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Sample records for climate change response

  1. Climate change, responsibility, and justice.

    PubMed

    Jamieson, Dale

    2010-09-01

    In this paper I make the following claims. In order to see anthropogenic climate change as clearly involving moral wrongs and global injustices, we will have to revise some central concepts in these domains. Moreover, climate change threatens another value ("respect for nature") that cannot easily be taken up by concerns of global justice or moral responsibility. PMID:19847671

  2. Geomorphic responses to climatic change

    SciTech Connect

    Bull, W.B.

    1991-01-01

    The primary focus of this book is the response of landscapes to Pleistocene and Holocene climatic changes. During the past 40 ky the global climate has varied from full-glacial to interglacial. Global temperatures decreased between 40 and 20 ka culminating in full-glacial climatic conditions at 20 ka. This resulted in a sea level decline of 130 m. Only 8 to 14 ky later the global temperature had reversed itself and the climate was the warmest of the past 120 ky. These dramatic changes in climate imposed significant controls on fluvial systems and impacted land forms and whole landscapes worldwide. Chapter 1, Conceptual Models for Changing landscapes, presents numerous concepts related to erosional and depositional processes controlling landscape development. Each of the next four chapters of the book, 2, 3, 4, and 5, examine different aspects of climatic change on fluvial systems. The conceptual models are used to analyze landscape response in four different climatic and geologic settings. In each setting the present and past climatic conditions, the climatically induced changes in vegetation and soil development, and geochronology are considered in assessing the influence of climatic changes on geomorphic processes. Chapter 2, investigates the influence of climatic change on the geomorphic processes operating in desert watersheds in the southwestern US and northern Mexico. The study sites for Chapter 3, are small desert drainage basins in the southwestern US and near the Sinai Peninsula in the Middle East. Chapter 4, investigates fill terraces in several drainage basins of the San Gabrial Mountains of the central Transverse Ranges of coastal southern California. The study site for Chapter 5 is the Charwell River watershed in the Seaward Kaikoura Range of New Zealand. Chapter 6, Difference Responses of Arid and Humid Fluvial Systems, compares the effects of changing climates in basins that range from extremely arid to humid.

  3. Mammalian Response to Cenozoic Climatic Change

    NASA Astrophysics Data System (ADS)

    Blois, Jessica L.; Hadly, Elizabeth A.

    2009-05-01

    Multiple episodes of rapid and gradual climatic changes influenced the evolution and ecology of mammalian species and communities throughout the Cenozoic. Climatic change influenced the abundance, genetic diversity, morphology, and geographic ranges of individual species. Within communities these responses interacted to catalyze immigration, speciation, and extinction. Combined they affected long-term patterns of community stability, functional turnover, biotic turnover, and diversity. Although the relative influence of climate on particular evolutionary processes is oft debated, an understanding of processes at the root of biotic change yields important insights into the complexity of mammalian response. Ultimately, all responses trace to events experienced by populations. However, many such processes emerge as patterns above the species level, where shared life history traits and evolutionary history allow us to generalize about mammalian response to climatic change. These generalizations provide the greatest power to understand and predict mammalian responses to current and future global change.

  4. Climate Change: The Public Health Response

    PubMed Central

    Frumkin, Howard; Hess, Jeremy; Luber, George; Malilay, Josephine; McGeehin, Michael

    2008-01-01

    There is scientific consensus that the global climate is changing, with rising surface temperatures, melting ice and snow, rising sea levels, and increasing climate variability. These changes are expected to have substantial impacts on human health. There are known, effective public health responses for many of these impacts, but the scope, timeline, and complexity of climate change are unprecedented. We propose a public health approach to climate change, based on the essential public health services, that extends to both clinical and population health services and emphasizes the coordination of government agencies (federal, state, and local), academia, the private sector, and nongovernmental organizations. PMID:18235058

  5. Ecological response to global climatic change

    USGS Publications Warehouse

    Malanson, G.P.; Butler, D.R.; Walsh, S. J.

    2004-01-01

    Climate change and ecological change go hand in hand. Because we value our ecological environment, any change has the potential to be a problem. Geographers have been drawn to this challenge, and have been successful in addressing it, because the primary ecological response to climate changes in the past — the waxing and waning of the great ice sheets over the past 2 million years – was the changing geographic range of the biota. Plants and animals changed their location. Geographers have been deeply involved in documenting the changing biota of the past, and today we are called upon to help assess the possible responses to ongoing and future climatic change and, thus, their impacts. Assessing the potential responses is important for policy makers to judge the outcomes of action or inaction and also sets the stage for preparation for and mitigation of change.

  6. CONTINENTAL SCALE BIOME RESPONSES TO CLIMATIC CHANGE

    EPA Science Inventory

    Current projections of climatic change call for a global average temperature increase of 2.8 to 5.2 degrees C and a 7% to 16% increase in rainfall by about 2030. he potential ecological responses to these changes have been estimated using a variety of techniques, but have general...

  7. Crop and pasture response to climate change.

    PubMed

    Tubiello, Francesco N; Soussana, Jean-François; Howden, S Mark

    2007-12-11

    We review recent research of importance to understanding crop and pasture plant species response to climate change. Topics include plant response to elevated CO(2) concentration, interactions with climate change variables and air pollutants, impacts of increased climate variability and frequency of extreme events, the role of weeds and pests, disease and animal health, issues in biodiversity, and vulnerability of soil carbon pools. We critically analyze the links between fundamental knowledge at the plant and plot level and the additional socio-economic variables that determine actual production and trade of food at regional to global scales. We conclude by making recommendations for current and future research needs, with a focus on continued and improved integration of experimental and modeling efforts. PMID:18077401

  8. Regional climate change and national responsibilities

    NASA Astrophysics Data System (ADS)

    Hansen, James; Sato, Makiko

    2016-03-01

    Global warming over the past several decades is now large enough that regional climate change is emerging above the noise of natural variability, especially in the summer at middle latitudes and year-round at low latitudes. Despite the small magnitude of warming relative to weather fluctuations, effects of the warming already have notable social and economic impacts. Global warming of 2 °C relative to preindustrial would shift the ‘bell curve’ defining temperature anomalies a factor of three larger than observed changes since the middle of the 20th century, with highly deleterious consequences. There is striking incongruity between the global distribution of nations principally responsible for fossil fuel CO2 emissions, known to be the main cause of climate change, and the regions suffering the greatest consequences from the warming, a fact with substantial implications for global energy and climate policies.

  9. Climate Change: Ethics and Collective Responsibility

    NASA Astrophysics Data System (ADS)

    Peacock, K.; Brown, M. B.; Mann, M. E.; Lewandowsky, S.

    2014-12-01

    Climate change poses grave risks for societies and people all around the earth. Though details of the risks remain uncertain, they include accelerating sea level rise and ocean acidification, regional drought, floods and heat waves, crop failures and more: dangerous changes are already occurring, while GHG emissions continue to grow, ice melts, water expands, temperature rises, and weather patterns shift. Our roles as individuals and nations in producing the emissions of GHGs responsible for this episode of climate change, and the actions that could be taken to mitigate it, raise difficult ethical questions. When we are responsible for putting others in danger, we have a duty to mitigate that danger. But our sense of responsibility is diluted here: each individual act contributes only minutely to the overall risks, and the links between individual acts and the harms they produce are complex, indirect and involve many other agents. In these circumstances, our sense of personal responsibility is diminished and uncoordinated, individual responses to the risks become ineffective. We propose a view of the ethics of climate change that begins with the tragedy of the commons: Free use of a shared, indispensable resource can lead to catastrophe as the resource is overrun, and the destruction of the commons arises from choices that are individuallyrational, if each person's choice is made independently of others'. Finally, individuals often fail to make ethical choices when the links between individual actions and their negative outcomes are obscure, when individual choices are made separately and privately, and when special interests stand to gain from actions that are generally harmful. Philosophical work in ethics has emphasized the role of ethics in enabling cooperation between individuals and coordinating group responses to problems, while recent work on social rules has modeled them as generalized forbiddings, taught and enforced by 'blocking' behaviours which

  10. Adaptation responses of crops to climate change

    SciTech Connect

    Seino, Hiroshi

    1993-12-31

    Appreciable global climatic responses to increasing levels of atmospheric CO{sub 2} and other trace gases are expected to take place over the next 50 to 80 years. Increasing atmospheric concentrations of carbon dioxide and other greenhouse gases are producing or will produce changes in the climate of the Earth. In particular, numerous efforts of climate modeling project very substantial increase of surface air temperature. In addition to a general warming of the atmosphere, the possibility of increased summer dryness in the continental mid-latitudes has been suggested on the basis of both historical analogues and some General Circulation Model (GCM) studies. There are three types of effect of climatic change on agriculture: (1) the physiological (direct) effect of elevated levels of atmospheric CO{sub 2} on crop plants and weeds, (2) the effect of changes in parameters of climate (e.g., temperature, precipitation, and solar radiation) on plants and animals, and (3) the effects of climate-related rises in sea-level on land use. The direct effects of elevated CO{sub 2} are on photosynthesis and respiration and thereby on growth, and there are additional effects of increased CO{sub 2} on development, yield quality and stomatal aperture and water use. A doubling of CO{sub 2} increases the instantaneous photosynthetic rate by 30% to 100%, depending on the other environmental conditions, and reduce water requirements of plants by reducing transpiration (per unit leaf area) through reductions in stomatal aperture. A doubling of CO{sub 2} causes partial stomatal closure on both C{sub 3} and C{sub 4} plants (approximately a 40% decrease in aperture). In many experiments this results in reductions of transpiration of about 23% to 46%. However. there is considerable uncertainty over the magnitude of this in natural conditions.

  11. Sensitivity and rapidity of vegetational response to abrupt climate change

    NASA Technical Reports Server (NTRS)

    Peteet, D.

    2000-01-01

    Rapid climate change characterizes numerous terrestrial sediment records during and since the last glaciation. Vegetational response is best expressed in terrestrial records near ecotones, where sensitivity to climate change is greatest, and response times are as short as decades.

  12. Undocumented migration in response to climate change

    PubMed Central

    Riosmena, Fernando; Hunter, Lori M.; Runfola, Daniel M.

    2016-01-01

    In the face of climate change induced economic uncertainty, households may employ migration as an adaptation strategy to diversify their livelihood portfolio through remittances. However, it is unclear whether such climate migration will be documented or undocumented. In this study we combine detailed migration histories with daily temperature and precipitation information for 214 weather stations to investigate whether climate change more strongly impacts undocumented or documented migration from 68 rural Mexican municipalities to the U.S. during the years 1986–1999. We employ two measures of climate change, the warm spell duration index (WSDI) and the precipitation during extremely wet days (R99PTOT). Results from multi-level event-history models demonstrate that climate-related international migration from rural Mexico was predominantly undocumented. We conclude that programs to facilitate climate change adaptation in rural Mexico may be more effective in reducing undocumented border crossings than increased border fortification.

  13. Simulating rice response to climate change

    SciTech Connect

    Singh, U.; Padilla, J.L. |

    1995-12-31

    The response of rice (Oryza sativa L.) to elevated CO{sub 2} concentration and temperature increase was simulated using the CERES-rice model. CERES-rice belongs to the International Benchmark Sites Network for Agrotechnology Transfer (IBSNAT) family of crop and nutrient dynamics models. Long-term historical data from the International Rice Research Institute (IRRI) wetland site was used to quantify the climatic change effects. The model simulated such beneficial effects of CO{sub 2} enrichment as increased grain yields, reduced transpiration, increased water use efficiency, improved use of intercepted radiation, reduced N losses, and higher N use efficiency. The trends were reversed for all of the above parameters with increase in temperature. CERES-rice simulated these negative trends in low input rice production as well. Based on the model`s prediction, some of the negative effects of temperature increase in warmer regions of the world could be offset by use of rice varieties that are tolerant to high temperature-induced spikelet sterility, and planting varieties with longer growth duration, particularly, longer grain filling duration. With improved varieties and good management future impact of climate change could be capitalized to have positive effects on rice production. Although the model has been extensively tested, it is critical to validate it with field data from extreme temperature and CO{sub 2} level studies. 33 refs., 13 figs., 3 tabs.

  14. Responses of large mammals to climate change

    PubMed Central

    Hetem, Robyn S; Fuller, Andrea; Maloney, Shane K; Mitchell, Duncan

    2014-01-01

    Most large terrestrial mammals, including the charismatic species so important for ecotourism, do not have the luxury of rapid micro-evolution or sufficient range shifts as strategies for adjusting to climate change. The rate of climate change is too fast for genetic adaptation to occur in mammals with longevities of decades, typical of large mammals, and landscape fragmentation and population by humans too widespread to allow spontaneous range shifts of large mammals, leaving only the expression of latent phenotypic plasticity to counter effects of climate change. The expression of phenotypic plasticity includes anatomical variation within the same species, changes in phenology, and employment of intrinsic physiological and behavioral capacity that can buffer an animal against the effects of climate change. Whether that buffer will be realized is unknown, because little is known about the efficacy of the expression of plasticity, particularly for large mammals. Future research in climate change biology requires measurement of physiological characteristics of many identified free-living individual animals for long periods, probably decades, to allow us to detect whether expression of phenotypic plasticity will be sufficient to cope with climate change.

  15. Responses of large mammals to climate change.

    PubMed

    Hetem, Robyn S; Fuller, Andrea; Maloney, Shane K; Mitchell, Duncan

    2014-01-01

    Most large terrestrial mammals, including the charismatic species so important for ecotourism, do not have the luxury of rapid micro-evolution or sufficient range shifts as strategies for adjusting to climate change. The rate of climate change is too fast for genetic adaptation to occur in mammals with longevities of decades, typical of large mammals, and landscape fragmentation and population by humans too widespread to allow spontaneous range shifts of large mammals, leaving only the expression of latent phenotypic plasticity to counter effects of climate change. The expression of phenotypic plasticity includes anatomical variation within the same species, changes in phenology, and employment of intrinsic physiological and behavioral capacity that can buffer an animal against the effects of climate change. Whether that buffer will be realized is unknown, because little is known about the efficacy of the expression of plasticity, particularly for large mammals. Future research in climate change biology requires measurement of physiological characteristics of many identified free-living individual animals for long periods, probably decades, to allow us to detect whether expression of phenotypic plasticity will be sufficient to cope with climate change. PMID:27583293

  16. Modeling Coastline Response to Changing Storm Climate

    NASA Astrophysics Data System (ADS)

    McNamara, D.; Murray, A. B.; Moore, L. J.; Brenner, O.

    2009-12-01

    Gradients in wave-driven alongshore sediment transport cause long-term change in the shape of sandy coastlines. Recent modeling work (Ashton, et. al. 2001; Ashton and Murray 2006) suggests coastlines can attain shapes that are in quasi-equilibrium with a regional wave climate—the distribution of wave influences as a function of deep-water wave-approach angles. Changes in storm frequency and/or magnitude will alter the wave climates affecting coastlines. Such a shift in wave forcing will tend to alter large-scale shapes of sedimentary coastlines (Slott et al., 2007). Even moderate changes in wave climate may cause coastlines to change shape rapidly, compared to a steady-wave-climate scenario. Such large-scale shape changes involve greatly accentuated rates of local erosion, and highly variable erosion/accretion rates. A recent analysis of wave records from the Southeastern US (Komar and Allen, 2007) indicates that wave climates have already been changing; for the past three decades, the heights of waves attributable to tropical storms have been increasing, changing the angular distribution of wave influences. These observations motivate ongoing, more refined modeling of how coastlines in this region should already be changing shape. Simulating patterns of shoreline change on actual coastlines involves examining the role of varying dynamical approximations in sub models of different environments (including wave propagation over the continental shelf) and uncertainties in model forcing (including the relationship between offshore buoy records and the wave climates affecting the coastline, when storm tracks often extend onshore of the buoy). Results suggest that modifications to the wave climate as recently seen along the Southeastern US give rise to rapid changes in shoreline shape and associated changes in patterns of erosion and accretion. Comparisons with results from related work, in which we examine historical and recent patterns of shoreline change for the

  17. Understanding complex biogeographic responses to climate change

    NASA Astrophysics Data System (ADS)

    Seabra, Rui; Wethey, David S.; Santos, António M.; Lima, Fernando P.

    2015-08-01

    Predicting the extent and direction of species’ range shifts is a major priority for scientists and resource managers. Seminal studies have fostered the notion that biological systems responding to climate change-impacted variables (e.g., temperature, precipitation) should exhibit poleward range shifts but shifts contrary to that expectation have been frequently reported. Understanding whether those shifts are indeed contrary to climate change predictions involves understanding the most basic mechanisms determining the distribution of species. We assessed the patterns of ecologically relevant temperature metrics (e.g., daily range, min, max) along the European Atlantic coast. Temperature metrics have contrasting geographical patterns and latitude or the grand mean are poor predictors for many of them. Our data suggest that unless the appropriate metrics are analysed, the impact of climate change in even a single metric of a single stressor may lead to range shifts in directions that would otherwise be classified as “contrary to prediction”.

  18. AO/NAO Response to Climate Change. 1; Respective Influences of Stratospheric and Tropospheric Climate Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.

    2005-01-01

    We utilize the GISS Global Climate Middle Atmosphere Model and 8 different climate change experiments, many of them focused on stratospheric climate forcings, to assess the relative influence of tropospheric and stratospheric climate change on the extratropical circulation indices (Arctic Oscillation, AO; North Atlantic Oscillation, NAO). The experiments are run in two different ways: with variable sea surface temperatures (SSTs) to allow for a full tropospheric climate response, and with specified SSTs to minimize the tropospheric change. The results show that tropospheric warming (cooling) experiments and stratospheric cooling (warming) experiments produce more positive (negative) AO/NAO indices. For the typical magnitudes of tropospheric and stratospheric climate changes, the tropospheric response dominates; results are strongest when the tropospheric and stratospheric influences are producing similar phase changes. Both regions produce their effect primarily by altering wave propagation and angular momentum transports, but planetary wave energy changes accompanying tropospheric climate change are also important. Stratospheric forcing has a larger impact on the NAO than on the AO, and the angular momentum transport changes associated with it peak in the upper troposphere, affecting all wavenumbers. Tropospheric climate changes influence both the A0 and NAO with effects that extend throughout the troposphere. For both forcings there is often vertical consistency in the sign of the momentum transport changes, obscuring the difference between direct and indirect mechanisms for influencing the surface circulation.

  19. What Can Plasticity Contribute to Insect Responses to Climate Change?

    PubMed

    Sgrò, Carla M; Terblanche, John S; Hoffmann, Ary A

    2016-01-01

    Plastic responses figure prominently in discussions on insect adaptation to climate change. Here we review the different types of plastic responses and whether they contribute much to adaptation. Under climate change, plastic responses involving diapause are often critical for population persistence, but key diapause responses under dry and hot conditions remain poorly understood. Climate variability can impose large fitness costs on insects showing diapause and other life cycle responses, threatening population persistence. In response to stressful climatic conditions, insects also undergo ontogenetic changes including hardening and acclimation. Environmental conditions experienced across developmental stages or by prior generations can influence hardening and acclimation, although evidence for the latter remains weak. Costs and constraints influence patterns of plasticity across insect clades, but they are poorly understood within field contexts. Plastic responses and their evolution should be considered when predicting vulnerability to climate change-but meaningful empirical data lag behind theory. PMID:26667379

  20. Urban Plantings: 'Living Laboratories' for Climate Change Response.

    PubMed

    Farrell, Claire; Szota, Christopher; Arndt, Stefan K

    2015-10-01

    Urban plantings are not only valuable resources for understanding 'urban plant physiology' but are 'living laboratories' for understanding plant response to climate change. Therefore, we encourage researchers who currently work in natural ecosystems to consider how urban plantings could enhance their research into plant physiological responses to a changing climate. PMID:26440428

  1. Climate change effects on agriculture: economic responses to biophysical shocks.

    PubMed

    Nelson, Gerald C; Valin, Hugo; Sands, Ronald D; Havlík, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina; Kyle, Page; Von Lampe, Martin; Lotze-Campen, Hermann; Mason d'Croz, Daniel; van Meijl, Hans; van der Mensbrugghe, Dominique; Müller, Christoph; Popp, Alexander; Robertson, Richard; Robinson, Sherman; Schmid, Erwin; Schmitz, Christoph; Tabeau, Andrzej; Willenbockel, Dirk

    2014-03-01

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change. PMID:24344285

  2. Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks

    NASA Technical Reports Server (NTRS)

    Nelson, Gerald C.; Valin, Hugo; Sands, Ronald D.; Havlik, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina

    2014-01-01

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  3. The physician's response to climate change.

    PubMed

    Sarfaty, Mona; Abouzaid, Safiya

    2009-05-01

    Climate change will have an effect on the health and well-being of the populations cared for by practicing physicians. The anticipated medical effects include heat- and cold-related deaths, cardiovascular illnesses, injuries and mental harms from extreme weather events, respiratory illnesses caused by poor air quality, infectious diseases that emanate from contaminated food, water, or spread of disease vectors, the injuries caused by natural disasters, and the mental harm associated with social disruption. Within several years, such medical problems are likely to reach the doorsteps of many physicians. In the face of this reality, physicians should assume their traditional roles as medical professionals, health educators, and community leaders. Clinicians provide individual health services to patients, some of whom will be especially vulnerable to the emerging health consequences of global warming. Physicians also work in academic medical institutions and hospitals that educate and provide continuing medical education to students, residents, and practitioners. The institutions also produce a measurable carbon footprint. Societies of physicians at national, state, and local levels can choose to use their well-developed avenues of communication to raise awareness of the key issues that are raised by climate change as well as other environmental concerns that have profound implications for human health and well-being. PMID:19418286

  4. Regional climate change, ecosystem responses, and climate feedbacks

    NASA Astrophysics Data System (ADS)

    Cook, Benjamin Issac

    2007-12-01

    I use empirical/statistical models and physically based general circulation models to assess the capacity for the Arctic Oscillation (AO) and the El Nino Southern Oscillation (ENSO) to influence terrestrial ecosystems, and the potential for those ecosystems to feedback to the climate system. AO warming leads to modest reductions in Eurasian carbon stocks; ˜17 Pg carbon are lost to the atmosphere, primarily from increased soil decomposition. Precipitation reductions in southern Africa associated with increased frequency of El Nino events lead to a reduction in tree cover and expansion of grasslands in the north and a reduction in grass cover in drier areas. Here half the carbon cycle changes are driven by the loss of tree cover, leading to a net loss of ˜5 Pg of carbon to the atmosphere. Over southern Africa, positive soil moisture anomalies lead to reduced precipitation through enhanced subsidence and reduced moisture convergence. Higher snow cover alone in Eurasia leads to minor albedo increases and moderate localized cooling (3°-5°C), mostly at very high latitudes (>70°N) and during the spring season. When vegetation is allowed to interact, increased snow cover leads to southward retreat of boreal vegetation, widespread cooling, and persistent snow cover over much of the boreal region during the boreal summer, with cold anomalies of up to 15°C. In southern Africa, the feedback experiments suggest a negative feedback between soil moisture and precipitation over the same area, implying this region may be resistant to externally forced changes in precipitation. In Eurasia, a persistent high phase of the AO leads to winter warming, but the feedback response is complicated. Warming during this season has been associated with increased snowfall, which could increase snow cover and albedo, countering the AO warming. Conversely, increased temperatures could lead to increased snow melting and decreased albedo, amplifying the AO warming.

  5. Shrinking body size as an ecological response to climate change

    NASA Astrophysics Data System (ADS)

    Sheridan, Jennifer A.; Bickford, David

    2011-11-01

    Determining how climate change will affect global ecology and ecosystem services is one of the next important frontiers in environmental science. Many species already exhibit smaller sizes as a result of climate change and many others are likely to shrink in response to continued climate change, following fundamental ecological and metabolic rules. This could negatively impact both crop plants and protein sources such as fish that are important for human nutrition. Furthermore, heterogeneity in response is likely to upset ecosystem balances. We discuss future research directions to better understand the trend and help ameliorate the trophic cascades and loss of biodiversity that will probably result from continued decreases in organism size.

  6. Geomorphic responses as indicators of paleoclimate and climatic change

    SciTech Connect

    1998-07-01

    There is little doubt that climate is an important parameter affecting the shape of the Earth`s surface. However absolute observance to the principles of climatic geomorphology leads us away from the study of processes because the analyses passes directly from climate to landscape form. An alternative approach is to examine the effects of climate change on the nature of the processes operating in the near surface environment. Utilizing this methodology, the climate-process relations take on greater significance, and lead to an understanding of the response(s) of geomorphic systems to shifts in climatic regime. Given that geomorphic systems respond to changes in climate regime, it should also be true that delineation of the changes in the types, rates, and magnitudes of geomorphic processes will provide insights into the timing and nature of past shifts in climate, particularly effective moisture. It is this approach that has been utilized herein. Specifically, geomorphic responses in eolian, lacustrine, and fluvial systems that have resulted in erosional and depositional events have been documented for several sites in Nevada (Figure 1), and used to infer the timing and character of climatic change in the Basin and Range Physiographic Province. The results and conclusions of the specific studies are provided.

  7. Climate change effects on agriculture: Economic responses to biophysical shocks

    PubMed Central

    Nelson, Gerald C.; Valin, Hugo; Sands, Ronald D.; Havlík, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina; Kyle, Page; Von Lampe, Martin; Lotze-Campen, Hermann; Mason d’Croz, Daniel; van Meijl, Hans; van der Mensbrugghe, Dominique; Müller, Christoph; Popp, Alexander; Robertson, Richard; Robinson, Sherman; Schmid, Erwin; Schmitz, Christoph; Tabeau, Andrzej; Willenbockel, Dirk

    2014-01-01

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change’s representative concentration pathway with end-of-century radiative forcing of 8.5 W/m2. The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change. PMID:24344285

  8. Conversion of Siberian Larch Forests in Response to Climate Change

    NASA Astrophysics Data System (ADS)

    Shuman, J. K.; Shugart, H. H.

    2009-12-01

    The Northern Hemisphere’s boreal forests and, in particular, the Siberian boreal forest zone, may have a particularly strong effect on the Earth’s climate through changes in the regional surface albedo. Warmer climate has been identified as a potential driver of the conversion of Siberia’s larch forests to dark-conifer forests of spruce and fir. This suggests a positive feedback cycle: warmer climate creates a succession from deciduous larch to dark-conifer forest; the resultant albedo change can then promote additional climate warming. The individual based forest growth model, FAREAST, which simulates the composition of the Russian forest, is used to test the impact of warming on forest succession and mitigation of this potential climate/cover feedback. Utilization of FAREAST with climate station and soil data from across Siberia generates baseline biomass (tCha-1) and species composition values from year zero to mature forest for current climate conditions. IPCC climate output data from two of NCAR’s Community Climate System Model 3.0 (CCSM) SRES climate change scenarios, which have stabilization at 720ppm of CO2 associated with 2.6°C warming and 550ppm CO2 with 1.2°C warming, are used to evaluate dominant species change in response to climate change. To explore mitigation of albedo changes associated with the predicted shift from larch to dark-conifer forest, the results for the current and two warming scenarios are compared to a set of model runs which introduce European Larch (Larix decidua). This deciduous species is adapted to warmer climate conditions and its introduction to Siberia could slow the rate of conversion to dark-conifer forests. Evaluation of climate as the driver for conversion of larch to dark-conifer enhances our ability to identify drivers of land surface change in this complex region and focus future analysis.

  9. Climate change effects on agriculture: Economic responses to biophysical shocks

    SciTech Connect

    Nelson, Gerald; Valin, Hugo; Sands, Ronald; Havlik, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina; Kyle, G. Page; von Lampe, Martin; Lotze-Campen, Hermann; Mason d'Croz, Daniel; van Meijl, Hans; van der Mensbrugghe, Dominique; Mueller, C.; Popp, Alexander; Robertson, Richard; Robinson, Sherman; Schmid, E.; Schmitz, Christoph; Tabeau, Andrzej; Willenbockel, Dirk

    2013-12-16

    Agricultural production is sensitive to weather and will thus be directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the IPCC’s Representative Concentration Pathway that result in end-of-century radiative forcing of 8.5 watts per square meter. The mean biophysical impact on crop yield with no incremental CO2 fertilization is a 17 percent reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11 percent, increase area of major crops by 12 percent, and reduce consumption by 2 percent. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences includes model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  10. Novel competitors shape species' responses to climate change.

    PubMed

    Alexander, Jake M; Diez, Jeffrey M; Levine, Jonathan M

    2015-09-24

    Understanding how species respond to climate change is critical for forecasting the future dynamics and distribution of pests, diseases and biological diversity. Although ecologists have long acknowledged species' direct physiological and demographic responses to climate, more recent work suggests that these direct responses can be overwhelmed by indirect effects mediated via other interacting community members. Theory suggests that some of the most dramatic impacts of community change will probably arise through the assembly of novel species combinations after asynchronous migrations with climate. Empirical tests of this prediction are rare, as existing work focuses on the effects of changing interactions between competitors that co-occur today. To explore how species' responses to climate warming depend on how their competitors migrate to track climate, we transplanted alpine plant species and intact plant communities along a climate gradient in the Swiss Alps. Here we show that when alpine plants were transplanted to warmer climates to simulate a migration failure, their performance was strongly reduced by novel competitors that could migrate upwards from lower elevation; these effects generally exceeded the impact of warming on competition with current competitors. In contrast, when we grew the focal plants under their current climate to simulate climate tracking, a shift in the competitive environment to novel high-elevation competitors had little to no effect. This asymmetry in the importance of changing competitor identity at the leading versus trailing range edges is best explained by the degree of functional similarity between current and novel competitors. We conclude that accounting for novel competitive interactions may be essential to predict species' responses to climate change accurately. PMID:26374998

  11. Climate change and mammals: evolutionary versus plastic responses

    PubMed Central

    Boutin, Stan; Lane, Jeffrey E

    2014-01-01

    Phenotypic plasticity and microevolution are the two primary means by which organisms respond adaptively to local conditions. While these mechanisms are not mutually exclusive, their relative magnitudes will influence both the rate of, and ability to sustain, phenotypic responses to climate change. We review accounts of recent phenotypic changes in wild mammal populations with the purpose of critically evaluating the following: (i) whether climate change has been identified as the causal mechanism producing the observed change; (ii) whether the change is adaptive; and (iii) the relative influences of evolution and/or phenotypic plasticity underlying the change. The available data for mammals are scant. We found twelve studies that report changes in phenology, body weight or litter size. In all cases, the observed response was primarily due to plasticity. Only one study (of advancing parturition dates in American red squirrels) provided convincing evidence of contemporary evolution. Subsequently, however, climate change has been shown to not be the causal mechanism underlying this shift. We also summarize studies that have shown evolutionary potential (i.e. the trait is heritable and/or under selection) in traits with putative associations with climate change and discuss future directions that need to be undertaken before a conclusive demonstration of plastic or evolutionary responses to climate change in wild mammals can be made. PMID:24454546

  12. Climate change and mammals: evolutionary versus plastic responses.

    PubMed

    Boutin, Stan; Lane, Jeffrey E

    2014-01-01

    Phenotypic plasticity and microevolution are the two primary means by which organisms respond adaptively to local conditions. While these mechanisms are not mutually exclusive, their relative magnitudes will influence both the rate of, and ability to sustain, phenotypic responses to climate change. We review accounts of recent phenotypic changes in wild mammal populations with the purpose of critically evaluating the following: (i) whether climate change has been identified as the causal mechanism producing the observed change; (ii) whether the change is adaptive; and (iii) the relative influences of evolution and/or phenotypic plasticity underlying the change. The available data for mammals are scant. We found twelve studies that report changes in phenology, body weight or litter size. In all cases, the observed response was primarily due to plasticity. Only one study (of advancing parturition dates in American red squirrels) provided convincing evidence of contemporary evolution. Subsequently, however, climate change has been shown to not be the causal mechanism underlying this shift. We also summarize studies that have shown evolutionary potential (i.e. the trait is heritable and/or under selection) in traits with putative associations with climate change and discuss future directions that need to be undertaken before a conclusive demonstration of plastic or evolutionary responses to climate change in wild mammals can be made. PMID:24454546

  13. Response of switchgrass yield to future climate change

    NASA Astrophysics Data System (ADS)

    Tulbure, Mirela G.; Wimberly, Michael C.; Owens, Vance N.

    2012-12-01

    A climate envelope approach was used to model the response of switchgrass, a model bioenergy species in the United States, to future climate change. The model was built using general additive models (GAMs), and switchgrass yields collected at 45 field trial locations as the response variable. The model incorporated variables previously shown to be the main determinants of switchgrass yield, and utilized current and predicted 1 km climate data from WorldClim. The models were run with current WorldClim data and compared with results of predicted yield obtained using two climate change scenarios across three global change models for three time steps. Results did not predict an increase in maximum switchgrass yield but showed an overall shift in areas of high switchgrass productivity for both cytotypes. For upland cytotypes, the shift in high yields was concentrated in northern and north-eastern areas where there were increases in average growing season temperature, whereas for lowland cultivars the areas where yields were projected to increase were associated with increases in average early growing season precipitation. These results highlight the fact that the influences of climate change on switchgrass yield are spatially heterogeneous and vary depending on cytotype. Knowledge of spatial distribution of suitable areas for switchgrass production under climate change should be incorporated into planning of current and future biofuel production. Understanding how switchgrass yields will be affected by future changes in climate is important for achieving a sustainable biofuels economy.

  14. Predicting the Response of Electricity Load to Climate Change

    SciTech Connect

    Sullivan, Patrick; Colman, Jesse; Kalendra, Eric

    2015-07-28

    Our purpose is to develop a methodology to quantify the impact of climate change on electric loads in the United States. We perform simple linear regression, assisted by geospatial smoothing, on paired temperature and load time-series to estimate the heating- and coolinginduced sensitivity to temperature across 300 transmission zones and 16 seasonal and diurnal time periods. The estimated load sensitivities can be coupled with climate scenarios to quantify the potential impact of climate change on load, with a primary application being long-term electricity scenarios. The method allows regional and seasonal differences in climate and load response to be reflected in the electricity scenarios. While the immediate product of this analysis was designed to mesh with the spatial and temporal resolution of a specific electricity model to enable climate change scenarios and analysis with that model, we also propose that the process could be applied for other models and purposes.

  15. Fast Vegetational Responses to Late-Glacial Climate Change

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Post, D. M.; Cwynar, L. C.; Lotter, A. F.; Levesque, A. J.

    2001-12-01

    How rapidly can natural ecosystems respond to rapid climate change? This question can be addressed by studying paired paleoecological and paleoclimatological records spanning the last deglaciation. Between 16 and 10 ka, abrupt climatic oscillations (e.g. Younger Dryas, Gerzensee/Killarney Oscillations) interrupted the general warming trend. Rates of climate change during these events were as fast or faster than projected rates of change for this century. We compiled a dozen high-resolution lacustrine records in North America and Europe with a pollen record and independent climatic proxy, a clear Younger Dryas signal, and good age control. Cross-correlation analysis suggests that vegetation responded rapidly to late-glacial climate change, with significant changes in vegetation composition occurring within the lifespan of individual trees. At all sites, vegetation lagged climate by less than 200 years, and at two-thirds of the sites, the initial vegetational response occurred within 100 years. The finding of rapid vegetational responses is consistent across sites and continents, and is similar to the 100-200 year response times predicted by gap-scale forest models. Likely mechanisms include 1) increased susceptibility of mature trees to disturbances such as fire, wind, and disease, thereby opening up gaps for colonization, 2) the proximity of these sites to late-glacial treeline, where climate may directly control plant population densities and range limits, 3) the presence of herbaceous taxa with short generation times in these plant communities, and 4) rapid migration due to rare long-distance seed dispersals. Our results are consistent with reports that plant ranges are already shifting in response to recent climate change, and suggest that these shifts will persist for the next several centuries. Widespread changes in plant distributions may affect surface-atmosphere interactions and will challenge attempts to manage ecosystems and conserve biodiversity.

  16. Canada's Landscape Response To Climate Change From Satellite Records

    NASA Astrophysics Data System (ADS)

    Latifovic, R.; Trishchenko, A.; Pouliot, D.

    2005-12-01

    Progress towards sustainability, including adaptation to climate change relies on our ability to monitor and predict impacts on the environment resulting from combined human and natural causes. The synthesis of current knowledge and quantitative impact assessments used by stakeholders and decision makers regarding climate change are founded on observations sustained over decades. Such long-term observations of the earth's surface and atmospheric properties can be provided to a large degree by earth observation systems. Satellite data contain valuable measurements of sufficient length and continuity to generate geophysical time series of land cover, leaf area index, cloud fraction, albedo, radiation, lake temperature and other land, atmosphere and water properties. In addition to studying climate change the information provided by such data, can be used in wide range of applications related to natural resource development, agriculture, environmental monitoring, and ocean surveillance. In response to this recognized need, under the project National Action on Climate Change in the framework of the Climate Change Program of Natural Resources Canada the generation of a comprehensive satellite data record has been initiated. The new archive includes AVHRR data at 1-km spatial resolution over Canada for 1985-2004 (20 years), SPOT/VGT 1&2 (1998-2004) and MODIS (2000-2005). The first evaluation of landscape response to global climate change at regional level using the new archive will be presented through examples related to land cover change, landscape productivity, and lake and sea ice variability.

  17. Plastic and evolutionary responses to climate change in fish

    PubMed Central

    Crozier, Lisa G; Hutchings, Jeffrey A

    2014-01-01

    The physical and ecological ‘fingerprints’ of anthropogenic climate change over the past century are now well documented in many environments and taxa. We reviewed the evidence for phenotypic responses to recent climate change in fish. Changes in the timing of migration and reproduction, age at maturity, age at juvenile migration, growth, survival and fecundity were associated primarily with changes in temperature. Although these traits can evolve rapidly, only two studies attributed phenotypic changes formally to evolutionary mechanisms. The correlation-based methods most frequently employed point largely to ‘fine-grained’ population responses to environmental variability (i.e. rapid phenotypic changes relative to generation time), consistent with plastic mechanisms. Ultimately, many species will likely adapt to long-term warming trends overlaid on natural climate oscillations. Considering the strong plasticity in all traits studied, we recommend development and expanded use of methods capable of detecting evolutionary change, such as the long term study of selection coefficients and temporal shifts in reaction norms, and increased attention to forecasting adaptive change in response to the synergistic interactions of the multiple selection pressures likely to be associated with climate change. PMID:24454549

  18. Analysing responses to climate change through the lens of reflexivity.

    PubMed

    Davidson, Debra

    2012-12-01

    Sociologists are increasingly directing attention toward social responses to climate change. As is true of any new field of inquiry, theoretical frameworks guiding the research to date have room for improvement. One advance could be achieved through closer engagement with Reflexivity Theory, particularly the work of Margaret Archer, who asks just how individuals come to give attention to certain problems, and formulate responses to them. Individuals vary significantly in regard to their understanding of and concern for anthropogenic climate change, and these standpoints in turn influence commitment to mitigation and adaptation. The emergent social interactions among all such agents in turn influence the morphogenetic trajectories through which social structures will evolve, but the role of 'meta-reflexives' is particularly crucial. Identifying pathways of individual climate change reflexivity can make a valuable contribution to our understanding of the potential for and nature of collective responses. In this paper, I explore climate change reflexivity, with particular attention to climate change meta-reflexives, through a qualitative analysis of personal interviews with residents of two small communities in Alberta, Canada. Applying Reflexivity Theory to this context articulates dimensions of reflexive processing not elaborated in current theoretical treatments, including future outlook and comfort with uncertainty, among others. PMID:23240835

  19. A Global Framework for Monitoring Phenological Responses to Climate Change

    SciTech Connect

    White, Michael A; Hoffman, Forrest M; Hargrove, William Walter; Nemani, Ramakrishna R

    2005-01-01

    Remote sensing of vegetation phenology is an important method with which to monitor terrestrial responses to climate change, but most approaches include signals from multiple forcings, such as mixed phenological signals from multiple biomes, urbanization, political changes, shifts in agricultural practices, and disturbances. Consequently, it is difficult to extract a clear signal from the usually assumed forcing: climate change. Here, using global 8 km 1982 to 1999 Normalized Difference Vegetation Index (NDVI) data and an eight-element monthly climatology, we identified pixels whose wavelet power spectrum was consistently dominated by annual cycles and then created phenologically and climatically self-similar clusters, which we term phenoregions. We then ranked and screened each phenoregion as a function of landcover homogeneity and consistency, evidence of human impacts, and political diversity. Remaining phenoregions represented areas with a minimized probability of non-climatic forcings and form elemental units for long-term phenological monitoring.

  20. Emergence, reductionism and landscape response to climate change

    NASA Astrophysics Data System (ADS)

    Harrison, Stephan; Mighall, Tim

    2010-05-01

    Predicting landscape response to external forcing is hampered by the non-linear, stochastic and contingent (ie dominated by historical accidents) forcings inherent in landscape evolution. Using examples from research carried out in southwest Ireland we suggest that non-linearity in landform evolution is likely to be a strong control making regional predictions of landscape response to climate change very difficult. While uncertainties in GCM projections have been widely explored in climate science much less attention has been directed by geomorphologists to the uncertainties in landform evolution under conditions of climate change and this problem may be viewed within the context of philosophical approaches to reductionsim and emergence. Understanding the present and future trajectory of landform change may also guide us to provide an enhanced appreciation of how landforms evolved in the past.

  1. SPRUCE: Spruce and Peatland Responses under Climatic and Environmental Change

    DOE Data Explorer

    SPRUCE is an experiment to assess the response of northern peatland ecosystems to increases in temperature and exposures to elevated atmospheric CO2 concentrations. It is the primary component of the Terrestrial Ecosystem Science Scientific Focus Area of ORNL's Climate Change Program, focused on terrestrial ecosystems and the mechanisms that underlie their responses to climatic change. The experimental work is to be conducted in a Picea mariana [black spruce] - Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). The site is located at the southern margin of the boreal peatland forest. It is an ecosystem considered especially vulnerable to climate change, and anticipated to be near its tipping point with respect to climate change. Responses to warming and interactions with increased atmospheric CO2 concentration are anticipated to have important feedbacks on the atmosphere and climate, because of the high carbon stocks harbored by such ecosystems.[copied from http://mnspruce.ornl.gov/] While some data files are restricted to access by project members only, others are available for public download now, even as research is being actively conducted.

  2. Response of seafloor ecosystems to abrupt global climate change

    NASA Astrophysics Data System (ADS)

    Moffitt, Sarah E.; Hill, Tessa M.; Roopnarine, Peter D.; Kennett, James P.

    2015-04-01

    Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; >5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation (>1.5 to <0.5 mLṡL-1 [O2]) associated with abrupt (<100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from <100 to >1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems.

  3. Response of seafloor ecosystems to abrupt global climate change

    PubMed Central

    Moffitt, Sarah E.; Hill, Tessa M.; Roopnarine, Peter D.; Kennett, James P.

    2015-01-01

    Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; >5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation (>1.5 to <0.5 mL⋅L−1 [O2]) associated with abrupt (<100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from <100 to >1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems. PMID:25825727

  4. Response of seafloor ecosystems to abrupt global climate change.

    PubMed

    Moffitt, Sarah E; Hill, Tessa M; Roopnarine, Peter D; Kennett, James P

    2015-04-14

    Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; >5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation (>1.5 to <0.5 mL⋅L(-1) [O2]) associated with abrupt (<100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from <100 to >1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems. PMID:25825727

  5. Choice of baseline climate data impacts projected species' responses to climate change.

    PubMed

    Baker, David J; Hartley, Andrew J; Butchart, Stuart H M; Willis, Stephen G

    2016-07-01

    Climate data created from historic climate observations are integral to most assessments of potential climate change impacts, and frequently comprise the baseline period used to infer species-climate relationships. They are often also central to downscaling coarse resolution climate simulations from General Circulation Models (GCMs) to project future climate scenarios at ecologically relevant spatial scales. Uncertainty in these baseline data can be large, particularly where weather observations are sparse and climate dynamics are complex (e.g. over mountainous or coastal regions). Yet, importantly, this uncertainty is almost universally overlooked when assessing potential responses of species to climate change. Here, we assessed the importance of historic baseline climate uncertainty for projections of species' responses to future climate change. We built species distribution models (SDMs) for 895 African bird species of conservation concern, using six different climate baselines. We projected these models to two future periods (2040-2069, 2070-2099), using downscaled climate projections, and calculated species turnover and changes in species-specific climate suitability. We found that the choice of baseline climate data constituted an important source of uncertainty in projections of both species turnover and species-specific climate suitability, often comparable with, or more important than, uncertainty arising from the choice of GCM. Importantly, the relative contribution of these factors to projection uncertainty varied spatially. Moreover, when projecting SDMs to sites of biodiversity importance (Important Bird and Biodiversity Areas), these uncertainties altered site-level impacts, which could affect conservation prioritization. Our results highlight that projections of species' responses to climate change are sensitive to uncertainty in the baseline climatology. We recommend that this should be considered routinely in such analyses. PMID:26950769

  6. Disentangling root responses to climate change in a semiarid grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Future ecosystem properties of grasslands will be driven largely by belowground plant biomass responses to climate change, whose understanding has been limited by experimental and technical constraints. We use a multi-faceted approach and a factorial field experiment to explore impacts of elevated C...

  7. CORAL RESPONSES TO CLIMATE AND LAND USE CHANGES

    EPA Science Inventory

    Fisher, William S., Debbie L. Santavy, John E. Rogers and Richard G. Zepp. In press. Coral Responses to Climate and Land Use Changes (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB R1019).

    Coral reefs have ex...

  8. RESPONSE AND FEEDBACKS OF FOREST ECOSYSTEMS TO GLOBAL CLIMATE CHANGE

    EPA Science Inventory

    The accumulation of greenhouse gases in the atmosphere over the past century is projected to cause a warming of the Earth. Climate Change predictions vary by region and terrestrial biosphere response, and feedbacks will be ecosystem specific. Forests play a major role in the Eart...

  9. Financial market response to extreme events indicating climatic change

    NASA Astrophysics Data System (ADS)

    Anttila-Hughes, J. K.

    2016-05-01

    A variety of recent extreme climatic events are considered to be strong evidence that the climate is warming, but these incremental advances in certainty often seem ignored by non-scientists. I identify two unusual types of events that are considered to be evidence of climate change, announcements by NASA that the global annual average temperature has set a new record, and the sudden collapse of major polar ice shelves, and then conduct an event study to test whether news of these events changes investors' valuation of energy companies, a subset of firms whose future performance is closely tied to climate change. I find evidence that both classes of events have influenced energy stock prices since the 1990s, with record temperature announcements on average associated with negative returns and ice shelf collapses associated with positive returns. I identify a variety of plausible mechanisms that may be driving these differential responses, discuss implications for energy markets' views on long-term regulatory risk, and conclude that investors not only pay attention to scientifically significant climate events, but discriminate between signals carrying different information about the nature of climatic change.

  10. Key ecological responses to nitrogen are altered by climate change

    USGS Publications Warehouse

    Greaver, T.L.; Clark, C.M.; Compton, J.E.; Vallano, D.; Talhelm, A. F.; Weaver, C.P.; Band, L.E.; Baron, J. S.; Davidson, E.A.; Tague, C.L.; Felker-Quinn, E.; Lynch, J.A.; Herrick, J.D.; Liu, L.; Goodale, C.L.; Novak, K. J.; Haeuber, R. A.

    2016-01-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  11. Climate change in the oceans: Human impacts and responses

    NASA Astrophysics Data System (ADS)

    Allison, Edward H.; Bassett, Hannah R.

    2015-11-01

    Although it has far-reaching consequences for humanity, attention to climate change impacts on the ocean lags behind concern for impacts on the atmosphere and land. Understanding these impacts, as well as society’s diverse perspectives and multiscale responses to the changing oceans, requires a correspondingly diverse body of scholarship in the physical, biological, and social sciences and humanities. This can ensure that a plurality of values and viewpoints is reflected in the research that informs climate policy and may enable the concerns of maritime societies and economic sectors to be heard in key adaptation and mitigation discussions.

  12. Western Mountain Initiative: predicting ecosystem responses to climate change

    USGS Publications Warehouse

    Baron, Jill S.; Peterson, David L.; Wilson, J.T.

    2008-01-01

    Mountain ecosystems of the western United States provide irreplaceable goods and services such as water, timber, biodiversity, and recreational opportunities, but their responses to climatic changes are complex and not well understood. The Western Mountain Initiative (WMI), a collaboration between USGS and U.S. Forest Service scientists, catalyzes assessment and synthesis of the effects of disturbance and climate change across western mountain areas, focusing on national parks and surrounding national forests. The WMI takes an ecosystem approach to science, integrating research across science disciplines at scales ranging from field studies to global trends.

  13. Climate change in the oceans: Human impacts and responses.

    PubMed

    Allison, Edward H; Bassett, Hannah R

    2015-11-13

    Although it has far-reaching consequences for humanity, attention to climate change impacts on the ocean lags behind concern for impacts on the atmosphere and land. Understanding these impacts, as well as society's diverse perspectives and multiscale responses to the changing oceans, requires a correspondingly diverse body of scholarship in the physical, biological, and social sciences and humanities. This can ensure that a plurality of values and viewpoints is reflected in the research that informs climate policy and may enable the concerns of maritime societies and economic sectors to be heard in key adaptation and mitigation discussions. PMID:26564848

  14. Contrasting responses of mean and extreme snowfall to climate change.

    PubMed

    O'Gorman, Paul A

    2014-08-28

    Snowfall is an important element of the climate system, and one that is expected to change in a warming climate. Both mean snowfall and the intensity distribution of snowfall are important, with heavy snowfall events having particularly large economic and human impacts. Simulations with climate models indicate that annual mean snowfall declines with warming in most regions but increases in regions with very low surface temperatures. The response of heavy snowfall events to a changing climate, however, is unclear. Here I show that in simulations with climate models under a scenario of high emissions of greenhouse gases, by the late twenty-first century there are smaller fractional changes in the intensities of daily snowfall extremes than in mean snowfall over many Northern Hemisphere land regions. For example, for monthly climatological temperatures just below freezing and surface elevations below 1,000 metres, the 99.99th percentile of daily snowfall decreases by 8% in the multimodel median, compared to a 65% reduction in mean snowfall. Both mean and extreme snowfall must decrease for a sufficiently large warming, but the climatological temperature above which snowfall extremes decrease with warming in the simulations is as high as -9 °C, compared to -14 °C for mean snowfall. These results are supported by a physically based theory that is consistent with the observed rain-snow transition. According to the theory, snowfall extremes occur near an optimal temperature that is insensitive to climate warming, and this results in smaller fractional changes for higher percentiles of daily snowfall. The simulated changes in snowfall that I find would influence surface snow and its hazards; these changes also suggest that it may be difficult to detect a regional climate-change signal in snowfall extremes. PMID:25164753

  15. High Resolution Modelling of Crop Response to Climate Change

    NASA Astrophysics Data System (ADS)

    Mirmasoudi, S. S.; Byrne, J. M.; MacDonald, R. J.; Lewis, D.

    2014-12-01

    Crop production is one of the most vulnerable sectors to climatic variability and change. Increasing atmospheric CO2 concentration and other greenhouse gases are causing increases in global temperature. In western North America, water supply is largely derived from mountain snowmelt. Climate change will have a significant impact on mountain snowpack and subsequently, the snow-derived water supply. This will strain water supplies and increase water demand in areas with substantial irrigation agriculture. Increasing temperatures may create heat stress for some crops regardless of soil water supply, and increasing surface O3 and other pollutants may damage crops and ecosystems. CO2 fertilization may or may not be an advantage in future. This work is part of a larger study that will address a series of questions based on a range of future climate scenarios for several watersheds in western North America. The key questions are: (1) how will snowmelt and rainfall runoff vary in future; (2) how will seasonal and inter-annual soil water supply vary, and how might that impacts food supplies; (3) how might heat stress impact (some) crops even with adequate soil water; (4) will CO2 fertilization alter crop yields; and (5) will pollution loads, particularly O3, cause meaningful changes to crop yields? The Generate Earth Systems Science (GENESYS) Spatial Hydrometeorological Model is an innovative, efficient, high-resolution model designed to assess climate driven changes in mountain snowpack derived water supplies. We will link GENESYS to the CROPWAT crop model system to assess climate driven changes in water requirement and associated crop productivity for a range of future climate scenarios. Literature bases studies will be utilised to develop approximate crop response functions for heat stress, CO2 fertilization and for O3 damages. The overall objective is to create modeling systems that allows meaningful assessment of agricultural productivity at a watershed scale under a

  16. America's Climate Choices: Informing an Effective Response to Climate Change (Invited)

    NASA Astrophysics Data System (ADS)

    Liverman, D. M.; McConnell, M. C.; Raven, P.

    2010-12-01

    At the request of Congress, the National Academy of Sciences convened a series of coordinated activities to provide advice on actions and strategies that the nation can take to respond to climate change. As part of this suite of activities, this study examines information needs and recommends ways the federal government can better inform responses by enhancing climate change and greenhouse gas information and reporting systems and by improving climate communication and education. Demand for better information to support climate-related decisions has grown rapidly as people, organizations, and governments have moved ahead with plans and actions to reduce greenhouse gas emissions and to adapt to the impacts of climate change. To meet this demand, good information systems and services are needed. Without such systems, decision makers cannot evaluate whether particular policies and actions are achieving their goals or should be modified. Although the many non-federal efforts to reduce emissions and/or adapt to future climate changes carry considerable potential to reduce risks related to climate change, there is currently no comprehensive way to assess the effectiveness of those efforts. In addition, the diverse climate change responses to date have resulted in a patchwork of regional, state, and local policies that has prompted many state and business leaders to call for the development of a more predictable and coherent policy environment at the federal level. This report demonstrates that the nation lacks comprehensive, robust, and credible information and reporting systems to inform climate choices and evaluate their effectiveness. This report also argues that decision makers can benefit from a systematic and iterative framework for responding to climate change, in which decisions and policies can be revised in light of new information and experience and that improved information and reporting systems allow for ongoing evaluation of responses to climate risks. The

  17. Book Review: Regional Hydrological Response to Climate Change

    NASA Technical Reports Server (NTRS)

    Koster, Randal

    1998-01-01

    The book being reviewed, Regional Hydrological Response to Climate Change, addresses the effects of global climate change, particularly global warming induced by greenhouse gas emissions, on hydrological budgets at the regional scale. As noted in its preface, the book consists of peer-reviewed papers delivered at scientific meetings held by the International Geographical Union Working Group on Regional Hydrological Response to Climate Change and Global Warming, supplemented with some additional chapters that round out coverage of the topic. The editors hope that this book will serve as "not only a record of current achievements, but also a stimulus to further hydrological research as the detail and spatial resolution of Global Climate Models improves". The reviewer found the background material on regional climatology to be valuable and the methodologies presented to be of interest. The value of the book is significantly diminished, however by the dated nature of some of the material and by large uncertainties in the predictions of regional precipitation change. The book would have been improved by a much more extensive documentation of the uncertainty associated with each step of the prediction process.

  18. Coccolithophore calcification response to past ocean acidification and climate change

    PubMed Central

    O’Dea, Sarah A.; Gibbs, Samantha J.; Bown, Paul R.; Young, Jeremy R.; Poulton, Alex J.; Newsam, Cherry; Wilson, Paul A.

    2014-01-01

    Anthropogenic carbon dioxide emissions are forcing rapid ocean chemistry changes and causing ocean acidification (OA), which is of particular significance for calcifying organisms, including planktonic coccolithophores. Detailed analysis of coccolithophore skeletons enables comparison of calcite production in modern and fossil cells in order to investigate biomineralization response of ancient coccolithophores to climate change. Here we show that the two dominant coccolithophore taxa across the Paleocene–Eocene Thermal Maximum (PETM) OA global warming event (~56 million years ago) exhibited morphological response to environmental change and both showed reduced calcification rates. However, only Coccolithus pelagicus exhibits a transient thinning of coccoliths, immediately before the PETM, that may have been OA-induced. Changing coccolith thickness may affect calcite production more significantly in the dominant modern species Emiliania huxleyi, but, overall, these PETM records indicate that the environmental factors that govern taxonomic composition and growth rate will most strongly influence coccolithophore calcification response to anthropogenic change. PMID:25399967

  19. Coccolithophore calcification response to past ocean acidification and climate change.

    PubMed

    O'Dea, Sarah A; Gibbs, Samantha J; Bown, Paul R; Young, Jeremy R; Poulton, Alex J; Newsam, Cherry; Wilson, Paul A

    2014-01-01

    Anthropogenic carbon dioxide emissions are forcing rapid ocean chemistry changes and causing ocean acidification (OA), which is of particular significance for calcifying organisms, including planktonic coccolithophores. Detailed analysis of coccolithophore skeletons enables comparison of calcite production in modern and fossil cells in order to investigate biomineralization response of ancient coccolithophores to climate change. Here we show that the two dominant coccolithophore taxa across the Paleocene-Eocene Thermal Maximum (PETM) OA global warming event (~56 million years ago) exhibited morphological response to environmental change and both showed reduced calcification rates. However, only Coccolithus pelagicus exhibits a transient thinning of coccoliths, immediately before the PETM, that may have been OA-induced. Changing coccolith thickness may affect calcite production more significantly in the dominant modern species Emiliania huxleyi, but, overall, these PETM records indicate that the environmental factors that govern taxonomic composition and growth rate will most strongly influence coccolithophore calcification response to anthropogenic change. PMID:25399967

  20. Adaptation potential of European agriculture in response to climate change

    NASA Astrophysics Data System (ADS)

    Moore, Frances C.; Lobell, David B.

    2014-07-01

    Projecting the impacts of climate change on agriculture requires knowing or assuming how farmers will adapt. However, empirical estimates of the effectiveness of this private adaptation are scarce and the sensitivity of impact assessments to adaptation assumptions is not well understood. Here we assess the potential effectiveness of private farmer adaptation in Europe by jointly estimating both short-run and long-run response functions using time-series and cross-sectional variation in subnational yield and profit data. The difference between the impacts of climate change projected using the short-run (limited adaptation) and long-run (substantial adaptation) response curves can be interpreted as the private adaptation potential. We find high adaptation potential for maize to future warming but large negative effects and only limited adaptation potential for wheat and barley. Overall, agricultural profits could increase slightly under climate change if farmers adapt but could decrease in many areas if there is no adaptation. Decomposing the variance in 2040 projected yields and farm profits using an ensemble of 13 climate model runs, we find that the rate at which farmers will adapt to rising temperatures is an important source of uncertainty.

  1. Modelling hydrological responses of Nerbioi River Basin to Climate Change

    NASA Astrophysics Data System (ADS)

    Mendizabal, Maddalen; Moncho, Roberto; Chust, Guillem; Torp, Peter

    2010-05-01

    Future climate change will affect aquatic systems on various pathways. Regarding the hydrological cycle, which is a very important pathway, changes in hydrometeorological variables (air temperature, precipitation, evapotranspiration) in first order impact discharges. The fourth report assessment of the Intergovernmental Panel for Climate Change indicates there is evidence that the recent warming of the climate system would result in more frequent extreme precipitation events, increased winter flood likelihoods, increased and widespread melting of snow and ice, longer and more widespread droughts, and rising sea level. Available research and climate model outputs indicate a range of hydrological impacts with likely to very likely probabilities (67 to 99%). For example, it is likely that up to 20% of the world population will live in areas where river flood potential could increase by the 2080s. In Spain, within the Atlantic basin, the hydrological variability will increase in the future due to the intensification of the positive phase of the North Atlantic Oscillation (NAO) index. This might cause flood frequency decreases, but its magnitude does not decrease. The generation of flood, its duration and magnitude are closely linked to changes in winter precipitation. The climatic conditions and relief of the Iberian Peninsula favour the generation of floods. In Spain, floods had historically strong socio-economic impacts, with more than 1525 victims in the past five decades. This upward trend of hydrological variability is expected to remain in the coming decades (medium uncertainty) when the intensification of the positive phase of the NAO index (MMA, 2006) is considered. In order to adapt or minimize climate change impacts in water resources, it is necessary to use climate projections as well as hydrological modelling tools. The main objective of this paper is to evaluate and assess the hydrological response to climate changes in flow conditions in Nerbioi river

  2. Interdependency of tropical marine ecosystems in response to climate change

    NASA Astrophysics Data System (ADS)

    Saunders, Megan I.; Leon, Javier X.; Callaghan, David P.; Roelfsema, Chris M.; Hamylton, Sarah; Brown, Christopher J.; Baldock, Tom; Golshani, Aliasghar; Phinn, Stuart R.; Lovelock, Catherine E.; Hoegh-Guldberg, Ove; Woodroffe, Colin D.; Mumby, Peter J.

    2014-08-01

    Ecosystems are linked within landscapes by the physical and biological processes they mediate. In such connected landscapes, the response of one ecosystem to climate change could have profound consequences for neighbouring systems. Here, we report the first quantitative predictions of interdependencies between ecosystems in response to climate change. In shallow tropical marine ecosystems, coral reefs shelter lagoons from incoming waves, allowing seagrass meadows to thrive. Deepening water over coral reefs from sea-level rise results in larger, more energetic waves traversing the reef into the lagoon, potentially generating hostile conditions for seagrass. However, growth of coral reef such that the relative water depth is maintained could mitigate negative effects of sea-level rise on seagrass. Parameterizing physical and biological models for Lizard Island, Great Barrier Reef, Australia, we find negative effects of sea-level rise on seagrass before the middle of this century given reasonable rates of reef growth. Rates of vertical carbonate accretion typical of modern reef flats (up to 3 mm yr-1) will probably be insufficient to maintain suitable conditions for reef lagoon seagrass under moderate to high greenhouse gas emissions scenarios by 2100. Accounting for interdependencies in ecosystem responses to climate change is challenging, but failure to do so results in inaccurate predictions of habitat extent in the future.

  3. Mammalian responses to Pleistocene climate change in southeastern Australia

    NASA Astrophysics Data System (ADS)

    Prideaux, Gavin J.; Roberts, Richard G.; Megirian, Dirk; Westaway, Kira E.; Hellstrom, John C.; Olley, Jon M.

    2007-01-01

    Resolving faunal responses to Pleistocene climate change is vital for differentiating human impacts from other drivers of ecological change. While 90% of Australia's large mammals were extinct by ca. 45 ka, their responses to glacial-interglacial cycling have remained unknown, due to a lack of rigorous biostratigraphic studies and the rarity of terrestrial climatic records that can be related directly to faunal records. We present an analysis of faunal data from the Naracoorte Caves in southeastern Australia, which are unique not only because of the species richness and time-depth of the assemblages that they contain, but also because this faunal record is directly comparable with a 500 k.y. speleothem-based record of local effective moisture. Our data reveal that, despite significant population fluctuations driven by glacial-interglacial cycling, the species composition of the mammal fauna was essentially stable for 500 k.y. before the late Pleistocene extinctions. Larger species declined during a drier interval between 270 and 220 ka, likely reflecting range contractions away from Naracoorte, but they then recovered locally, persisting well into the late Pleistocene. Because the speleothem record and prior faunal response imply that local conditions should have been favorable for megafauna until at least 30 ka, climate change is unlikely to have been the principal cause of the extinctions.

  4. Loss of adaptive variation during evolutionary responses to climate change.

    PubMed

    Buckley, James; Bridle, Jon R

    2014-10-01

    The changes in species' geographical distribution demanded by climate change are often critically limited by the availability of key interacting species. In such cases, species' persistence will depend on the rapid evolution of biotic interactions. Understanding evolutionary limits to such adaptation is therefore crucial for predicting biological responses to environmental change. The recent poleward range expansion of the UK brown argus butterfly has been associated with a shift in female preference from its main host plant, rockrose (Cistaceae), onto Geraniaceae host plants throughout its new distribution. Using reciprocal transplants onto natural host plants across the UK range, we demonstrate reduced fitness of females from recently colonised Geraniaceae-dominated habitat when moved to ancestral rockrose habitats. By contrast, individuals from ancestral rockrose habitats show no reduction in fitness on Geraniaceae. Climate-driven range expansion in this species is therefore associated with the rapid evolution of biotic interactions and a significant loss of adaptive variation. PMID:25104062

  5. The demographic response to Holocene climate change in the Sahara

    NASA Astrophysics Data System (ADS)

    Manning, Katie; Timpson, Adrian

    2014-10-01

    The timing and development of Holocene human occupation in the now hyperarid Sahara has major implications for understanding links between climate change, demography and cultural adaptation. Here we use summed probability distributions from 3287 calibrated 14C dates from 1011 archaeological sites to demonstrate a major and rapid demographic shift between 10,500 and 5500 years BP. This event corresponds with the African Humid Period (AHP) and is sub-continental in scale, indicating climate as the prime factor driving broad-scale population dynamics in northern Africa. Furthermore, by providing a high temporal resolution proxy for effective carrying capacity our population curve offers an independent estimate of environmental change in northern Africa, indicating a temporal delay in the terrestrial response to atmospheric climate change. These results highlight the degree to which human demography is a function of environment at the appropriate scale of observation in both time and space and sheds important new light on the social response to global environmental change.

  6. A Paleoindian response to Younger Dryas climate change

    NASA Astrophysics Data System (ADS)

    Newby, Paige; Bradley, James; Spiess, Arthur; Shuman, Bryan; Leduc, Phillip

    2005-01-01

    Late Quaternary changes in North American vegetation and geography reflect the influence of changing climate induced by the retreating ice sheets, orbitally-driven seasonal insolation patterns, increasing carbon dioxide concentrations, and relatively rapid internal variations. At regional scales, these climate changes resulted in ecosystem variability that impacted human access to resources. We use paleoenvironmental and archaeological records from 14,000 to 10,000 cal yr BP for New England and Maritime Canada (NE/M) to propose the impact of rapid climate change on human resource-procurement and technology. Paleoenvironmental reconstructions for the Younger Dryas chronozone (YDC; 12,900-11,600 cal yr BP) show ecologic responses to colder-than-earlier conditions. At roughly the same time (13,000-11,000 cal yr BP), we surmise that fluted points were used to hunt large mammals, including caribou, which inhabited regions with sub-arctic-like vegetation. Environmental changes, associated with rapid regional warming at the end of the YDC, coincided with the abandonment of fluting technology. As conditions warmed, vegetation changes led to shifts in animal populations, which may be reflected in the development of other point styles by Paleoindians and subsequent human groups.

  7. Responses of vegetation growth to climate change in china

    NASA Astrophysics Data System (ADS)

    Li, Z.; Zhou, T.

    2015-04-01

    Global warming-related climate changes have significantly impacted the growth of terrestrial vegetation. Quantifying the spatiotemporal characteristic of the vegetation's response to climate is crucial for assessing the potential impacts of climate change on vegetation. In this study, we employed the normalized difference vegetation index (NDVI) and the standardized precipitation evapotranspiration index (SPEI) that was calculated for various time scales (1 to 12 months) from monthly records of mean temperature and precipitation totals using 511 meteorological stations in China to study the response of vegetation types to droughts. We separated the NDVI into 12 time series (one per month) and also used the SPEI of 12 droughts time scales to make the correlation. The results showed that the differences exist in various vegetation types. For needle-leaved forest, broadleaf forest and shrubland, they responded to droughts at long time scales (9 to 12 months). For grassland, meadow and cultivated vegetation, they responded to droughts at short time scales (1 to 5months). The positive correlations were mostly found in arid and sub-arid environments where soil water was a primary constraining factor for plant growth, and the negative correlations always existed in humid environments where temperature and radiation played significant roles in vegetation growth. Further spatial analysis indicated that the positive correlations were primarily found in northern China, especially in northwestern China, which is a region that always has water deficit, and the negative correlations were found in southern China, especially in southeastern China, that is a region has water surplus most of the year. The disclosed patterns of spatiotemporal responses to droughts are important for studying the impact of climate change to vegetation growth.

  8. The acceptability of climate change in agricultural communities: comparing responses across variability and change.

    PubMed

    Raymond, Christopher M; Spoehr, John

    2013-01-30

    This study examined how the terms used to describe climate change influence landholder acceptability judgements and attitudes toward climate change at the local scale. Telephone surveys were conducted with landholders from viticultural (n = 97) or cereal growing (n = 195) backgrounds in rural South Australia. A variety of descriptive and inferential statistics were used to examine the influence of human-induced climate change and winter/spring drying trend terms on adaptation responses and uncertainties surrounding climate change science. We found that the terms used to describe climate change leads to significant differences in adaptation response and levels of scepticism surrounding climate change in rural populations. For example, those respondents who accepted human induced climate change as a reality were significantly more likely to invest in technologies to sow crops earlier or increase the amount of water stored or harvested on their properties than respondents who accepted the winter/spring drying trend as a reality. The results have implications for the targeting of climate change science messages to both rural landholders and communities of practice involved in climate change adaptation planning and implementation. PMID:23246767

  9. Climate Change

    MedlinePlus

    Climate is the average weather in a place over a period of time. Climate change is major change in temperature, rainfall, snow, ... by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. ...

  10. Climate Change

    MedlinePlus

    ... in a place over a period of time. Climate change is major change in temperature, rainfall, snow, or ... by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate ...

  11. Landscape fragmentation affects responses of avian communities to climate change.

    PubMed

    Jarzyna, Marta A; Porter, William F; Maurer, Brian A; Zuckerberg, Benjamin; Finley, Andrew O

    2015-08-01

    Forecasting the consequences of climate change is contingent upon our understanding of the relationship between biodiversity patterns and climatic variability. While the impacts of climate change on individual species have been well-documented, there is a paucity of studies on climate-mediated changes in community dynamics. Our objectives were to investigate the relationship between temporal turnover in avian biodiversity and changes in climatic conditions and to assess the role of landscape fragmentation in affecting this relationship. We hypothesized that community turnover would be highest in regions experiencing the most pronounced changes in climate and that these patterns would be reduced in human-dominated landscapes. To test this hypothesis, we quantified temporal turnover in avian communities over a 20-year period using data from the New York State Breeding Atlases collected during 1980-1985 and 2000-2005. We applied Bayesian spatially varying intercept models to evaluate the relationship between temporal turnover and temporal trends in climatic conditions and landscape fragmentation. We found that models including interaction terms between climate change and landscape fragmentation were superior to models without the interaction terms, suggesting that the relationship between avian community turnover and changes in climatic conditions was affected by the level of landscape fragmentation. Specifically, we found weaker associations between temporal turnover and climatic change in regions with prevalent habitat fragmentation. We suggest that avian communities in fragmented landscapes are more robust to climate change than communities found in contiguous habitats because they are comprised of species with wider thermal niches and thus are less susceptible to shifts in climatic variability. We conclude that highly fragmented regions are likely to undergo less pronounced changes in composition and structure of faunal communities as a result of climate change

  12. Hydrological Response to Climate Change over the Blue Nile Basin Distributed hydrological modeling based on surrogate climate change scenarios

    NASA Astrophysics Data System (ADS)

    Berhane, F. G.; Anyah, R. O.

    2010-12-01

    The program Soil and Water Assessment Tool (SWAT2009) model has been applied to the Blue Nile Basin to study the hydrological response to surrogate climate changes over the Blue Nile Basin (Ethiopia) by downscaling gridded weather data. The specific objectives of the study include (i) examining the performance of the SWAT model in simulating hydrology-climate interactions and feedbacks within the entire Blue Nile Basin, and (ii) investigating the response of hydrological variables to surrogate climate changes. Monthly weather data from the Climate Research Unit (CRU) are converted to daily values as input into the SWAT using Monthly to Daily Weather Converter (MODAWEC). Using the program SUFI-2 (Sequential Uncertainty Fitting Algorithm), data from 1979 to 1983 are applied for sensitivity analysis and calibration (P-factor = 90%, R-factor =0.7, R2 =0.93 and NS=0.93) and subsequently to validate hindcasts over the period 1984-1989 (R2 =0.92 and NS=0.92). The period from 1960-2000 was used as baseline and has been used to determine the changes and the effect of the surrogate climate changes over the Blue Nile Basin. Overall, our surrogate climate change based simulations indicate the hydrology of the Blue Nile catchment is very sensitive to potential climate change with 100%, 34% and 51% increase to the surface runoff, lateral flow and water yield respectively for the A2 scenario surrogate. Key Words: SWAT, MODAWEC, Blue Nile Basin, SUFI-2, climate change, hydrological modeling, CRU

  13. Warming experiments underpredict plant phenological responses to climate change

    USGS Publications Warehouse

    Wolkovich, Elizabeth M.; Cook, Benjamin I.; Allen, Jenica M.; Crimmins, Theresa M.; Betancourt, Julio L.; Travers, Steven E.; Pau, Stephanie; Regetz, James; Davies, T. Jonathan; Kraft, Nathan J.B.; Ault, Toby R.; Bolmgren, Kjell; Mazer, Susan J.; McCabe, Gregory J.; McGill, Brian J.; Parmesan, Camille; Salamin, Nicolas; Schwartz, Mark D.; Cleland, Elsa E.

    2012-01-01

    Warming experiments are increasingly relied on to estimate plant responses to global climate change. For experiments to provide meaningful predictions of future responses, they should reflect the empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing. We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.

  14. Warming Experiments Underpredict Plant Phenological Responses to Climate Change

    NASA Technical Reports Server (NTRS)

    Wolkovich, E. M.; Cook, B. I.; Allen, J. M.; Crimmins, T. M.; Betancourt, J. L.; Travers, S. E.; Pau, S.; Regetz, J.; Davies, T. J.; Kraft, N. J. B.; Ault, T. R.; Bolmgren, K.; Mazer, S. J.; McCabe, G. J.; McGill, B. J.; Parmesan, C.; Salamin, N.; Schwartz, M. D.; Cleland, E. E.

    2012-01-01

    Warming experiments are increasingly relied on to estimate plant responses to global climate change. For experiments to provide meaningful predictions of future responses, they should reflect the empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing. We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.

  15. Response of soybean to predicted climate change in the USA

    SciTech Connect

    Curry, R.B.; Jones, J.W.; Boote, K.J.; Peart, R.M.; Allen, L.H. Jr.; Pickering, N.B.

    1995-12-31

    Soybean [Glycine max (L.) Merr.] is a major crop in the USA in terms of production, exports, and area of land used in its production. Projected changes in climate could have major impacts on the production of this crop as well as on areas where it would be produced. A simulation study was conducted to characterize these possible effects using a soybean crop growth model, historical weather data, and three possible climate change scenarios based on global climate model (GCM) results. For each weather scenario, rainfed and irrigation management cases were studied under normal and elevated atmospheric CO{sub 2} levels. Results showed that the high annual variability of rainfed soybean yields under historical weather conditions was amplified by the GCM-based climate change scenarios. The negative effects of climate change alone on soybean yields were mostly offset by the increased atmospheric CO{sub 2} concentration for two of the scenarios for both irrigated and rainfed cases. The third scenario resulted in decreased yields in most locations. On average, the climate change scenarios resulted in a 60% increase in estimated water requirements for irrigation. These results suggest that soybean production in the USA would not be adversely affected by climate change if the climate changes according to two of the GCMs, unless water supply for irrigation is limited. Under the most severe climate change scenario, however, soybean production in the USA could be reduced considerably unless changes in production regions and practices are made. 31 refs., 11 figs., 6 tabs.

  16. Stationary monitoring of glacier response to climate change in China

    NASA Astrophysics Data System (ADS)

    Ren, Jiawen; Li, Zhongqin; Qin, Xiang; He, Yuanqing; He, Xiaobo; Li, Huilin

    2016-04-01

    At present, there are about 48571 glaciers with a total area of about 51.8×103 km2 and a volume of about 5.6×103 km3 in China. They are distributed widely in the high mountains in and surrounding the Tibetan Plateau and other high mountains such as Tianshan, Altay and Pamir. In view of differences in climatic conditions and glacier types, stationary monitoring of the glacier variations has been ongoing in different regions in order to investigate the glacier response to climate change. The monitoring results show that all the monitoring glaciers have been in retreat during the past decades and especially since 1990's the retreat rate has an accelerating trend. The accumulative mass balance is much negative and has a large annual variability for the monsoonal maritime glaciers in comparison with the continental and sub-continental glaciers. Under climate warming background, the acceleration of glacier melting is mainly attributed to rise in air temperature, ice temperature augment and albedo reduction of glacier surface. Particularly, the albedo reduction has a positive feedback effect on the glacier melting. Based on long term observation of glacier variations and physical properties, a simple dynamics model is coupled with mass balance modeling to make a projection of a typical glacier change in future. The primary modeling results suggest that the glacier will continue in shrinkage until vanishing within 50-90 years.

  17. Global Responses to Potential Climate Change: A Simulation.

    ERIC Educational Resources Information Center

    Williams, Mary Louise; Mowry, George

    This interdisciplinary five-day unit provides students with an understanding of the issues in the debate on global climate change. Introductory lessons enhance understanding of the "greenhouse gases" and their sources with possible global effects of climate change. Students then roleplay negotiators from 10 nations in a simulation of the…

  18. A Systems Perspective on Responses to Climate Change

    EPA Science Inventory

    The science of climate change integrates many scientific fields to explain and predict the complex effects of greenhouse gas concentrations on the planet’s energy balance, weather patterns, and ecosystems as well as economic and social systems. A changing climate requires respons...

  19. Climate Change and Societal Response: Livelihoods, Communities, and the Environment

    ERIC Educational Resources Information Center

    Molnar, Joseph J.

    2010-01-01

    Climate change may be considered a natural disaster evolving in slow motion on a global scale. Increasing storm intensities, shifting rainfall patterns, melting glaciers, rising sea levels, and other manifold alterations are being experienced around the world. Climate has never been constant in any location, but human-induced changes associated…

  20. Modeling Transient Response of Forests to Climate Change

    SciTech Connect

    Dale, Virginia H; Tharp, M Lynn; Lannom, Karen O.; Hodges, Donald G

    2010-01-01

    Our hypothesis is that a high diversity of dominant life forms in Tennessee forests conveys resilience to disturbance such as climate change. Because of uncertainty in climate change and their effects, three climate change scenarios for 2030 and 2080 from three General Circulation Models (GCMs) were used to simulate a range of potential climate conditions for the state. These climate changes derive from the Intergovernmental Panel on Climate Change (IPCC) A1B storyline that assumes rapid global economic growth. The precipitation and temperature projections from the three GCMs for 2030 and 2080 were related to changes in five ecological provinces using the monthly record of temperature and precipitation from 1980 to 1997 for each 1 km cell across the state as aggregated into the provinces. Temperatures are projected to increase in all ecological provinces in all months for all three GCMs for both 2030 and 2080. Precipitation differences from the long-term average are more complex but less striking. The forest ecosystem model LINKAGES was used to simulate conditions for five ecological provinces from 1989 to 2300. Average output projects changes in tree diversity and species composition in all ecological provinces in Tennessee with the greatest changes in the Southern Mixed Forest province. Projected declines in total tree biomass are followed by biomass recovery as species replacement occurs in stands. The Southern Mixed Forest province results in less diversity in dominant trees as well as lower overall biomass than projections for the other four provinces. The biomass and composition changes projected in this study differ from forest dynamics expected without climate change. These results suggest that biomass recovery following climate change is linked to dominant tree diversity in the southeastern forest of the US. The generality of this observation warrants further investigation, for it relates to ways that forest management may influence climate change effects.

  1. Population variability complicates the accurate detection of climate change responses.

    PubMed

    McCain, Christy; Szewczyk, Tim; Bracy Knight, Kevin

    2016-06-01

    The rush to assess species' responses to anthropogenic climate change (CC) has underestimated the importance of interannual population variability (PV). Researchers assume sampling rigor alone will lead to an accurate detection of response regardless of the underlying population fluctuations of the species under consideration. Using population simulations across a realistic, empirically based gradient in PV, we show that moderate to high PV can lead to opposite and biased conclusions about CC responses. Between pre- and post-CC sampling bouts of modeled populations as in resurvey studies, there is: (i) A 50% probability of erroneously detecting the opposite trend in population abundance change and nearly zero probability of detecting no change. (ii) Across multiple years of sampling, it is nearly impossible to accurately detect any directional shift in population sizes with even moderate PV. (iii) There is up to 50% probability of detecting a population extirpation when the species is present, but in very low natural abundances. (iv) Under scenarios of moderate to high PV across a species' range or at the range edges, there is a bias toward erroneous detection of range shifts or contractions. Essentially, the frequency and magnitude of population peaks and troughs greatly impact the accuracy of our CC response measurements. Species with moderate to high PV (many small vertebrates, invertebrates, and annual plants) may be inaccurate 'canaries in the coal mine' for CC without pertinent demographic analyses and additional repeat sampling. Variation in PV may explain some idiosyncrasies in CC responses detected so far and urgently needs more careful consideration in design and analysis of CC responses. PMID:26725404

  2. 77 FR 76034 - National Water Program 2012 Strategy: Response to Climate Change

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... AGENCY National Water Program 2012 Strategy: Response to Climate Change AGENCY: Environmental Protection... publishing the final ``National Water Program 2012 Strategy: Response to Climate Change'' (2012 Strategy... light of climate change and charts key strategic actions to be taken to achieve the goals in 2012...

  3. Biogeochemical responses of shallow coastal lagoons to Climate Change

    NASA Astrophysics Data System (ADS)

    Brito, A.; Newton, A.; Tett, P.; Fernandes, T.

    2009-04-01

    carefully monitored so that appropriate responses can be timely to mitigate the impacts from global change. References: Eisenreich, S.J. (2005). Climate Change and the European Water Dimension - A report to the European Water Directors. Institute for Environment and Sustainability, European Comission-Joint Research Centre. Ispra, Italy. 253pp. Kerr, R. (2008). Global warming throws some curves in the Atlantic Ocean. Science, 322, 515. IPCC (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K., Tignor, M., Miller, H. (eds.)]. Cambridge University Press. Cambridge, United Kingdom and New York, NY, USA, 996pp. Lloret, J., Marín, A., Marín-Guirao, L. (2008). Is coastal lagoon eutrophication likely to be aggravated by global climate change? Estuarine, Coastal and Shelf Science, 78, 403-412. Snoussi, M., Ouchani, T., Niazi, S. (2008). Vulnerability assessment of the impact of sea-level rise and flooding on the Moroccan coast: The case of the Mediterranean eastern zone. Estuarine, Coastal and Shelf Science, 77, 206-213.

  4. Venezuelan policies and responses on climate change and natural hazards

    NASA Astrophysics Data System (ADS)

    Caponi, Claudio; Rosales, Anibal

    1992-06-01

    Venezuela is an intertropical country which has the fortune not to suffer the severities of natural hazards which are usual in other countries of this region. It is a developing country, whose economy is heavily dependent on oil production and exports. Its greenhouse gas emissions are relatively low, but it is expected that the planned industrialization development will bring an associated increase in emissions. As a nation, Venezuela has a highly developed environmental consciousness. The Ministry of environment, the first in Latin America, was created in 1977, and has been the main contributor to the national policy of Disaster Prevention and Reduction. As in many developing countries actions and responses in this regard have been rather limited in scope, and even though legislation has been developed, many problems arise for its enforcement. Several local warning systems, civil defense procedures, and infrastructural protection measures are operational, however they have not been designed, revised, or planned taking into consideration the potential impacts of climate change. Presently Venezuela is an active participant state in the negotiation for a framework convention on climate change. That is a very difficult negotiation for our country. Here we have to conciliate enviromental principles with national economic interests. The elements of our position in this contex are presented in this statement.

  5. Adaptation responses to climate change differ between global megacities

    NASA Astrophysics Data System (ADS)

    Georgeson, Lucien; Maslin, Mark; Poessinouw, Martyn; Howard, Steve

    2016-06-01

    Urban areas are increasingly at risk from climate change, with negative impacts predicted for human health, the economy and ecosystems. These risks require responses from cities to improve their resilience. Policymakers need to understand current adaptation spend to plan comprehensively and effectively. Through the measurement of spend in the newly defined `adaptation economy', we analyse current climate change adaptation efforts in ten megacities. In all cases, the adaptation economy remains a small part of the overall economy, representing a maximum of 0.33% of a city's gross domestic product (here referred to as GDPc). Differences in total spend are significant between cities in developed, emerging and developing countries, ranging from #15 million to #1,600 million. Comparing key subsectors, we demonstrate the differences in adaptation profiles. Developing cities have higher proportional spend on health and agriculture, whereas developed cities have higher spend on energy and water. Spend per capita and percentage of GDPc comparisons more clearly show disparities between cities. Developing country cities spend half the proportion of GDPc and significantly less per capita, suggesting that adaptation spend is driven by wealth rather than the number of vulnerable people. This indicates that current adaptation activities are insufficient in major population centres in developing and emerging economies.

  6. Hydrological Responses to Land-Use Change Scenarios under Constant and Changed Climatic Conditions.

    PubMed

    Zhang, Ling; Nan, Zhuotong; Yu, Wenjun; Ge, Yingchun

    2016-02-01

    This study quantified the hydrological responses to land-use change scenarios in the upper and middle Heihe River basin (HRB), northwest China, under constant and changed climatic conditions by combining a land-use/cover change model (dynamic conversion of land use and its effects, Dyna-CLUE) and a hydrological model (soil and water assessment tool, SWAT). Five land-use change scenarios, i.e., historical trend (HT), ecological protection (EP), strict ecological protection (SEP), economic development (ED), and rapid economic development (RED) scenarios, were established. Under constant climatic condition, hydrological variations are only induced by land-use changes in different scenarios. The changes in mean streamflow at the outlets of the upper and the middle HRB are not pronounced, although the different scenarios produce different outcomes. However, more pronounced changes are observed on a subbasin level. The frequency of extreme flood is projected to decrease under the SEP scenario, while under the other scenarios, no changes can be found. Two emission scenarios (A1B and B1) of three general circulation models (HadCM3, CGCM3, and CCSM3) were employed to generate future possible climatic conditions. Under changed climatic condition, hydrological variations are induced by the combination of land-use and climatic changes. The results indicate that the impacts of land-use changes become secondary when the changed climatic conditions have been considered. The frequencies of extreme flood and drought are projected to decrease and increase, respectively, under all climate scenarios. Although some agreements can be reached, pronounced difference of hydrological responses can be observed for different climate scenarios of different GCMs. PMID:26429363

  7. Hydrological Responses to Land-Use Change Scenarios under Constant and Changed Climatic Conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Nan, Zhuotong; Yu, Wenjun; Ge, Yingchun

    2016-02-01

    This study quantified the hydrological responses to land-use change scenarios in the upper and middle Heihe River basin (HRB), northwest China, under constant and changed climatic conditions by combining a land-use/cover change model (dynamic conversion of land use and its effects, Dyna-CLUE) and a hydrological model (soil and water assessment tool, SWAT). Five land-use change scenarios, i.e., historical trend (HT), ecological protection (EP), strict ecological protection (SEP), economic development (ED), and rapid economic development (RED) scenarios, were established. Under constant climatic condition, hydrological variations are only induced by land-use changes in different scenarios. The changes in mean streamflow at the outlets of the upper and the middle HRB are not pronounced, although the different scenarios produce different outcomes. However, more pronounced changes are observed on a subbasin level. The frequency of extreme flood is projected to decrease under the SEP scenario, while under the other scenarios, no changes can be found. Two emission scenarios (A1B and B1) of three general circulation models (HadCM3, CGCM3, and CCSM3) were employed to generate future possible climatic conditions. Under changed climatic condition, hydrological variations are induced by the combination of land-use and climatic changes. The results indicate that the impacts of land-use changes become secondary when the changed climatic conditions have been considered. The frequencies of extreme flood and drought are projected to decrease and increase, respectively, under all climate scenarios. Although some agreements can be reached, pronounced difference of hydrological responses can be observed for different climate scenarios of different GCMs.

  8. Wildfire responses to abrupt climate change in North America

    PubMed Central

    Marlon, J. R.; Bartlein, P. J.; Walsh, M. K.; Harrison, S. P.; Brown, K. J.; Edwards, M. E.; Higuera, P. E.; Power, M. J.; Anderson, R. S.; Briles, C.; Brunelle, A.; Carcaillet, C.; Daniels, M.; Hu, F. S.; Lavoie, M.; Long, C.; Minckley, T.; Richard, P. J. H.; Scott, A. C.; Shafer, D. S.; Tinner, W.; Umbanhowar, C. E.; Whitlock, C.

    2009-01-01

    It is widely accepted, based on data from the last few decades and on model simulations, that anthropogenic climate change will cause increased fire activity. However, less attention has been paid to the relationship between abrupt climate changes and heightened fire activity in the paleorecord. We use 35 charcoal and pollen records to assess how fire regimes in North America changed during the last glacial–interglacial transition (15 to 10 ka), a time of large and rapid climate changes. We also test the hypothesis that a comet impact initiated continental-scale wildfires at 12.9 ka; the data do not support this idea, nor are continent-wide fires indicated at any time during deglaciation. There are, however, clear links between large climate changes and fire activity. Biomass burning gradually increased from the glacial period to the beginning of the Younger Dryas. Although there are changes in biomass burning during the Younger Dryas, there is no systematic trend. There is a further increase in biomass burning after the Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and 11.7 ka are marked by large increases in fire activity. The timing of changes in fire is not coincident with changes in human population density or the timing of the extinction of the megafauna. Although these factors could have contributed to fire-regime changes at individual sites or at specific times, the charcoal data indicate an important role for climate, and particularly rapid climate change, in determining broad-scale levels of fire activity. PMID:19190185

  9. Climate Change Impacts and Responses: Societal Indicators for the National Climate Assessment

    NASA Technical Reports Server (NTRS)

    Kenney, Melissa A.; Chen, Robert S.; Maldonado, Julie; Quattrochi, Dale

    2011-01-01

    The Climate Change Impacts and Responses: Societal Indicators for the National Climate Assessment workshop, sponsored by the National Aeronautics and Space Administration (NASA) for the National Climate Assessment (NCA), was held on April 28-29, 2011 at The Madison Hotel in Washington, DC. A group of 56 experts (see list in Appendix B) convened to share their experiences. Participants brought to bear a wide range of disciplinary expertise in the social and natural sciences, sector experience, and knowledge about developing and implementing indicators for a range of purposes. Participants included representatives from federal and state government, non-governmental organizations, tribes, universities, and communities. The purpose of the workshop was to assist the NCA in developing a strategic framework for climate-related physical, ecological, and socioeconomic indicators that can be easily communicated with the U.S. population and that will support monitoring, assessment, prediction, evaluation, and decision-making. The NCA indicators are envisioned as a relatively small number of policy-relevant integrated indicators designed to provide a consistent, objective, and transparent overview of major variations in climate impacts, vulnerabilities, adaptation, and mitigation activities across sectors, regions, and timeframes. The workshop participants were asked to provide input on a number of topics, including: (1) categories of societal indicators for the NCA; (2) alternative approaches to constructing indicators and the better approaches for NCA to consider; (3) specific requirements and criteria for implementing the indicators; and (4) sources of data for and creators of such indicators. Socioeconomic indicators could include demographic, cultural, behavioral, economic, public health, and policy components relevant to impacts, vulnerabilities, and adaptation to climate change as well as both proactive and reactive responses to climate change. Participants provided

  10. A replicated climate change field experiment reveals rapid evolutionary response in an ecologically important soil invertebrate.

    PubMed

    Bataillon, Thomas; Galtier, Nicolas; Bernard, Aurelien; Cryer, Nicolai; Faivre, Nicolas; Santoni, Sylvain; Severac, Dany; Mikkelsen, Teis N; Larsen, Klaus S; Beier, Claus; Sørensen, Jesper G; Holmstrup, Martin; Ehlers, Bodil K

    2016-07-01

    Whether species can respond evolutionarily to current climate change is crucial for the persistence of many species. Yet, very few studies have examined genetic responses to climate change in manipulated experiments carried out in natural field conditions. We examined the evolutionary response to climate change in a common annelid worm using a controlled replicated experiment where climatic conditions were manipulated in a natural setting. Analyzing the transcribed genome of 15 local populations, we found that about 12% of the genetic polymorphisms exhibit differences in allele frequencies associated to changes in soil temperature and soil moisture. This shows an evolutionary response to realistic climate change happening over short-time scale, and calls for incorporating evolution into models predicting future response of species to climate change. It also shows that designed climate change experiments coupled with genome sequencing offer great potential to test for the occurrence (or lack) of an evolutionary response. PMID:27109012

  11. Measured Climate Induced Volume Changes of Three Glaciers and Current Glacier-Climate Response Prediction

    NASA Astrophysics Data System (ADS)

    Trabant, D. C.; March, R. S.; Cox, L. H.; Josberger, E. G.

    2003-12-01

    Small but hydrologically significant shifts in climate have affected the rates of glacier volume change at the three U.S. Geological Survey Benchmark glaciers. Rate changes are detected as inflections in the cumulative conventional and reference-surface mass-balances of Wolverine and Gulkana Glaciers in Alaska and South Cascade Glacier in Washington. The cumulative mass balances are robust and have recently been corroborated by geodetic determinations of glacier volume change. Furthermore, the four-decade length of record is unique for the western hemisphere. Balance trends at South Cascade Glacier in Washington are generally in the opposite sense compared with Wolverine Glacier in Alaska; NCEP correlation of winter balance with local winter temperatures is positive at 0.59 for Wolverine and -0.64 for South Cascade Glacier. At Wolverine Glacier, the negative trend of cumulative mass balances, since measurements began in 1965, was replaced by a growth trend \\(positive mass balances\\) during the late 1970s and 1980s. The positive mass-balance trend was driven by increased precipitation during the 1976/77 to 1989 period. At Gulkana Glacier, the cumulative mass-balance trend has been negative throughout its measurement history, but with rate-change inflection points that coincide with the interdecadal climate-regime shifts in the North Pacific indices. At South Cascade Glacier, the mass-loss trend, observed since measurements began in 1953, was replaced by a positive trend between 1970 and 1976 then became strongly and continuously negative until 1997 when the rate of loss generally decreased. Since 1989, the trends of the glaciers in Alaska have also been strongly negative. These loss rates are the highest rates in the entire record. The strongly negative trends during the 1990s agree with climate studies that suggest that the period since the 1989 regime shift has been unusual. Volume response time and reference surface balance are the current suggested methods for

  12. Pleistocene Climate, Phylogeny, and Climate Envelope Models: An Integrative Approach to Better Understand Species' Response to Climate Change

    PubMed Central

    Lawing, A. Michelle; Polly, P. David

    2011-01-01

    Mean annual temperature reported by the Intergovernmental Panel on Climate Change increases at least 1.1°C to 6.4°C over the next 90 years. In context, a change in climate of 6°C is approximately the difference between the mean annual temperature of the Last Glacial Maximum (LGM) and our current warm interglacial. Species have been responding to changing climate throughout Earth's history and their previous biological responses can inform our expectations for future climate change. Here we synthesize geological evidence in the form of stable oxygen isotopes, general circulation paleoclimate models, species' evolutionary relatedness, and species' geographic distributions. We use the stable oxygen isotope record to develop a series of temporally high-resolution paleoclimate reconstructions spanning the Middle Pleistocene to Recent, which we use to map ancestral climatic envelope reconstructions for North American rattlesnakes. A simple linear interpolation between current climate and a general circulation paleoclimate model of the LGM using stable oxygen isotope ratios provides good estimates of paleoclimate at other time periods. We use geologically informed rates of change derived from these reconstructions to predict magnitudes and rates of change in species' suitable habitat over the next century. Our approach to modeling the past suitable habitat of species is general and can be adopted by others. We use multiple lines of evidence of past climate (isotopes and climate models), phylogenetic topology (to correct the models for long-term changes in the suitable habitat of a species), and the fossil record, however sparse, to cross check the models. Our models indicate the annual rate of displacement in a clade of rattlesnakes over the next century will be 2 to 3 orders of magnitude greater (430-2,420 m/yr) than it has been on average for the past 320 ky (2.3 m/yr). PMID:22164305

  13. Climate Change and Trophic Response of the Antarctic Bottom Fauna

    PubMed Central

    Aronson, Richard B.; Moody, Ryan M.; Ivany, Linda C.; Blake, Daniel B.; Werner, John E.; Glass, Alexander

    2009-01-01

    Background As Earth warms, temperate and subpolar marine species will increasingly shift their geographic ranges poleward. The endemic shelf fauna of Antarctica is especially vulnerable to climate-mediated biological invasions because cold temperatures currently exclude the durophagous (shell-breaking) predators that structure shallow-benthic communities elsewhere. Methodology/Principal Findings We used the Eocene fossil record from Seymour Island, Antarctic Peninsula, to project specifically how global warming will reorganize the nearshore benthos of Antarctica. A long-term cooling trend, which began with a sharp temperature drop ∼41 Ma (million years ago), eliminated durophagous predators—teleosts (modern bony fish), decapod crustaceans (crabs and lobsters) and almost all neoselachian elasmobranchs (modern sharks and rays)—from Antarctic nearshore waters after the Eocene. Even prior to those extinctions, durophagous predators became less active as coastal sea temperatures declined from 41 Ma to the end of the Eocene, ∼33.5 Ma. In response, dense populations of suspension-feeding ophiuroids and crinoids abruptly appeared. Dense aggregations of brachiopods transcended the cooling event with no apparent change in predation pressure, nor were there changes in the frequency of shell-drilling predation on venerid bivalves. Conclusions/Significance Rapid warming in the Southern Ocean is now removing the physiological barriers to shell-breaking predators, and crabs are returning to the Antarctic Peninsula. Over the coming decades to centuries, we predict a rapid reversal of the Eocene trends. Increasing predation will reduce or eliminate extant dense populations of suspension-feeding echinoderms from nearshore habitats along the Peninsula while brachiopods will continue to form large populations, and the intensity of shell-drilling predation on infaunal bivalves will not change appreciably. In time the ecological effects of global warming could spread to other

  14. Complex response of the forest nitrogen cycle to climate change.

    PubMed

    Bernal, Susana; Hedin, Lars O; Likens, Gene E; Gerber, Stefan; Buso, Don C

    2012-02-28

    Climate exerts a powerful influence on biological processes, but the effects of climate change on ecosystem nutrient flux and cycling are poorly resolved. Although rare, long-term records offer a unique opportunity to disentangle effects of climate from other anthropogenic influences. Here, we examine the longest and most complete record of watershed nutrient and climate dynamics available worldwide, which was collected at the Hubbard Brook Experimental Forest in the northeastern United States. We used empirical analyses and model calculations to distinguish between effects of climate change and past perturbations on the forest nitrogen (N) cycle. We find that climate alone cannot explain the occurrence of a dramatic >90% drop in watershed nitrate export over the past 46 y, despite longer growing seasons and higher soil temperatures. The strongest climate influence was an increase in soil temperature accompanied by a shift in paths of soil water flow within the watershed, but this effect explained, at best, only ∼40% of the nitrate decline. In contrast, at least 50-60% of the observed change in the N export could be explained by the long-lasting effect of forest cutting in the early 1900s on the N cycle of the soil and vegetation pools. Our analysis shows that historic events can obscure the influence of modern day stresses on the N cycle, even when analyses have the advantage of being informed by 0.5-century-long datasets. These findings raise fundamental questions about interpretations of long-term trends as a baseline for understanding how climate change influences complex ecosystems. PMID:22331889

  15. Response of salt-marsh carbon accumulation to climate change.

    PubMed

    Kirwan, Matthew L; Mudd, Simon M

    2012-09-27

    About half of annual marine carbon burial takes place in shallow water ecosystems where geomorphic and ecological stability is driven by interactions between the flow of water, vegetation growth and sediment transport. Although the sensitivity of terrestrial and deep marine carbon pools to climate change has been studied for decades, there is little understanding of how coastal carbon accumulation rates will change and potentially feed back on climate. Here we develop a numerical model of salt marsh evolution, informed by recent measurements of productivity and decomposition, and demonstrate that competition between mineral sediment deposition and organic-matter accumulation determines the net impact of climate change on carbon accumulation in intertidal wetlands. We find that the direct impact of warming on soil carbon accumulation rates is more subtle than the impact of warming-driven sea level rise, although the impact of warming increases with increasing rates of sea level rise. Our simulations suggest that the net impact of climate change will be to increase carbon burial rates in the first half of the twenty-first century, but that carbon-climate feedbacks are likely to diminish over time. PMID:23018965

  16. Dynamic response of desert wetlands to abrupt climate change

    PubMed Central

    Springer, Kathleen B.; Manker, Craig R.; Pigati, Jeffrey S.

    2015-01-01

    Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated 14C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming. PMID:26554007

  17. Dynamic response of desert wetlands to abrupt climate change.

    PubMed

    Springer, Kathleen B; Manker, Craig R; Pigati, Jeffrey S

    2015-11-24

    Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated (14)C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming. PMID:26554007

  18. Dynamic response of desert wetlands to abrupt climate change

    USGS Publications Warehouse

    Springer, Kathleen; Manker, Craig; Pigati, Jeff

    2015-01-01

    Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated 14C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming.

  19. California climate change, hydrologic response, and flood forecasting

    SciTech Connect

    Miller, Norman L.

    2003-11-11

    There is strong evidence that the lower atmosphere has been warming at an unprecedented rate during the last 50 years, and it is expected to further increase at least for the next 100 years. Warmer air mass implies a higher capacity to hold water vapor and an increased likelihood of an acceleration of the global water cycle. This acceleration is not validated and considerable new research has gone into understanding aspects of the water cycle (e.g. Miller et al. 2003). Several significant findings on the hydrologic response to climate change can be reported. It is well understood that the observed and expected warming is related to sea level rise. In a recent seminar at Lawrence Berkeley National Laboratory, James Hansen (Director of the Institute for Space Studies, National Aeronautics and Space Administration) stressed that a 1.25 Wm{sup -2} increase in radiative forcing will lead to an increase in the near surface air temperature by 1 C. This small increase in temperature from 2000 levels is enough to cause very significant impacts to coasts. Maury Roos (Chief Hydrologist, California Department of Water Resources) has shown that a 0.3 m rise in sea level shifts the San Francisco Bay 100-year storm surge flood event to a 10-year event. Related coastal protection costs for California based on sea level rise are shown. In addition to rising sea level, snowmelt-related streamflow represents a particular problem in California. Model studies have indicated that there will be approximately a 50% decrease in snow pack by 2100. This potential deficit must be fully recognized and plans need to be put in place well in advance. In addition, the warmer atmosphere can hold more water vapor and result in more intense warm winter-time precipitation events that result in flooding. During anticipated high flow, reservoirs need to release water to maintain their structural integrity. California is at risk of water shortages, floods, and related ecosystem stresses. More research

  20. A plant’s perspective of extremes: Terrestrial plant responses to changing climatic variability

    PubMed Central

    Reyer, C.; Leuzinger, S.; Rammig, A.; Wolf, A.; Bartholomeus, R. P.; Bonfante, A.; de Lorenzi, F.; Dury, M.; Gloning, P.; Abou Jaoudé, R.; Klein, T.; Kuster, T. M.; Martins, M.; Niedrist, G.; Riccardi, M.; Wohlfahrt, G.; de Angelis, P.; de Dato, G.; François, L.; Menzel, A.; Pereira, M.

    2013-01-01

    We review observational, experimental and model results on how plants respond to extreme climatic conditions induced by changing climatic variability. Distinguishing between impacts of changing mean climatic conditions and changing climatic variability on terrestrial ecosystems is generally underrated in current studies. The goals of our review are thus (1) to identify plant processes that are vulnerable to changes in the variability of climatic variables rather than to changes in their mean, and (2) to depict/evaluate available study designs to quantify responses of plants to changing climatic variability. We find that phenology is largely affected by changing mean climate but also that impacts of climatic variability are much less studied but potentially damaging. We note that plant water relations seem to be very vulnerable to extremes driven by changes in temperature and precipitation and that heatwaves and flooding have stronger impacts on physiological processes than changing mean climate. Moreover, interacting phenological and physiological processes are likely to further complicate plant responses to changing climatic variability. Phenological and physiological processes and their interactions culminate in even more sophisticated responses to changing mean climate and climatic variability at the species and community level. Generally, observational studies are well suited to study plant responses to changing mean climate, but less suitable to gain a mechanistic understanding of plant responses to climatic variability. Experiments seem best suited to simulate extreme events. In models, temporal resolution and model structure are crucial to capture plant responses to changing climatic variability. We highlight that a combination of experimental, observational and /or modeling studies have the potential to overcome important caveats of the respective individual approaches. PMID:23504722

  1. Abundance changes and habitat availability drive species' responses to climate change

    NASA Astrophysics Data System (ADS)

    Mair, Louise; Hill, Jane K.; Fox, Richard; Botham, Marc; Brereton, Tom; Thomas, Chris D.

    2014-02-01

    There is little consensus as to why there is so much variation in the rates at which different species' geographic ranges expand in response to climate warming. Here we show that the relative importance of species' abundance trends and habitat availability for British butterfly species vary over time. Species with high habitat availability expanded more rapidly from the 1970s to mid-1990s, when abundances were generally stable, whereas habitat availability effects were confined to the subset of species with stable abundances from the mid-1990s to 2009, when abundance trends were generally declining. This suggests that stable (or positive) abundance trends are a prerequisite for range expansion. Given that species' abundance trends vary over time for non-climatic as well as climatic reasons, assessment of abundance trends will help improve predictions of species' responses to climate change, and help us to understand the likely success of different conservation strategies for facilitating their expansions.

  2. The insect response to climate change: Perspectives from the Quaternary record

    SciTech Connect

    Ashworth, A.C.; Schwert, D.P. . Quaternary Entomology Lab.)

    1993-03-01

    Data based on museum collections of insects are generally inadequate to answer questions related to the response of insects to recent and potential changes in climate. The most important source of information for this purpose is the late Quaternary fossil record. Abundant, well-preserved, [sup 14]C-dated assemblages of insect fossils provide information with which to answer the following questions: (1) will climate change result in speciation--all evidence suggests that species are constant through the climate changes of the late Quaternary, future climate change would not be expected to result in accelerated rates of speciation; (2) will climate change result in extinction--few species became extinct as a result of the large-scale changes in climate and physical environment during the quaternary, although large-scale extirpation might occur, future climate change would not be expected to result in widespread extinction of species; (3) will climate change result in changes in geographic distribution--species survived late Quaternary climatic change through the ability of individuals to disperse into suitable habitats. The result was large changes in geographic distribution of species, as exemplified by the succession of faunal changes that occurred in response to the climatic changes of the late Wisconsinan in the midcontinent, future climate change would be expected to result in significant range changes of species.

  3. Psychological responses to the proximity of climate change

    NASA Astrophysics Data System (ADS)

    Brügger, Adrian; Dessai, Suraje; Devine-Wright, Patrick; Morton, Thomas A.; Pidgeon, Nicholas F.

    2015-12-01

    A frequent suggestion to increase individuals' willingness to take action on climate change and to support relevant policies is to highlight its proximal consequences, that is, those that are close in space and time. But previous studies that have tested this proximizing approach have not revealed the expected positive effects on individual action and support for addressing climate change. We present three lines of psychological reasoning that provide compelling arguments as to why highlighting proximal impacts of climate change might not be as effective a way to increase individual mitigation and adaptation efforts as is often assumed. Our contextualization of the proximizing approach within established psychological research suggests that, depending on the particular theoretical perspective one takes on this issue, and on specific individual characteristics suggested by these perspectives, proximizing can bring about the intended positive effects, can have no (visible) effect or can even backfire. Thus, the effects of proximizing are much more complex than is commonly assumed. Revealing this complexity contributes to a refined theoretical understanding of the role that psychological distance plays in the context of climate change and opens up further avenues for future research and for interventions.

  4. Climate change compromises the immune response of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is by quantity the most important C4 cereal crop in the US; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2] is a driving force behind the warmer temperatures and drought, whi...

  5. Priorities in Soil Carbon Research in Response to Climate Change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Addressing the emerging issues associated with managing soil C is needed to provide environmental services, including mitigation of climate change due to atmospheric enrichment of CO2, and necessitates the identification of important research and development priorities. Important among these are the...

  6. The History of Germany's Response to Climate Change.

    ERIC Educational Resources Information Center

    Cavender, Jeannine; Jager, Jill

    1993-01-01

    Traces the history of the German climate change debate in the last 50 years and discusses the forces and events that shaped it. Examines the way in which scientists, the government, industry, nongovernmental organizations, and the media entered into and influenced the debate. (54 references) (MDH)

  7. Soil management challenges in response to climatic change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture has tremendous potential to help solve global food, feed, fiber, and bioenergy challenges and respond to changing climatic conditions provided we do not compromise our soil, water and air resources. This presentation will examine soil management, defined by the Soil Science Society of Am...

  8. Plasticity and genetic adaptation mediate amphibian and reptile responses to climate change

    PubMed Central

    Urban, Mark C; Richardson, Jonathan L; Freidenfelds, Nicole A

    2014-01-01

    Phenotypic plasticity and genetic adaptation are predicted to mitigate some of the negative biotic consequences of climate change. Here, we evaluate evidence for plastic and evolutionary responses to climate variation in amphibians and reptiles via a literature review and meta-analysis. We included studies that either document phenotypic changes through time or space. Plasticity had a clear and ubiquitous role in promoting phenotypic changes in response to climate variation. For adaptive evolution, we found no direct evidence for evolution of amphibians or reptiles in response to climate change over time. However, we found many studies that documented adaptive responses to climate along spatial gradients. Plasticity provided a mixture of adaptive and maladaptive responses to climate change, highlighting that plasticity frequently, but not always, could ameliorate climate change. Based on our review, we advocate for more experiments that survey genetic changes through time in response to climate change. Overall, plastic and genetic variation in amphibians and reptiles could buffer some of the formidable threats from climate change, but large uncertainties remain owing to limited data. PMID:24454550

  9. Changes in grassland ecosystem function due to extreme rainfall events: implications for responses to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change driven by increasing atmospheric CO2 concentrations is causing measurable changes in precipitation patterns. Most climate change scenarios forecast continuing increases in extreme precipitation patterns for North American terrestrial ecosystems, manifest as larger precipitation event...

  10. Business Responses to Climate Change. Identifying Emergent Strategies

    SciTech Connect

    Kolk, A.; Pinkse, J.

    2005-07-01

    Companies face much uncertainty about the competitive effects of the recently adopted Kyoto Protocol on global climate change and the current and future regulations that may emerge from it. Companies have considerable discretion to explore different market strategies to address global warming and reduce greenhouse gas emissions. This article examines these strategic options by reviewing the market-oriented actions that are currently being taken by 136 large companies that are part of the Global 500. There are six different market strategies that companies use to address climate change and that consist of different combinations of the market components available to managers. Managers can choose between more emphasis on improvements in their business activities through innovation or employ compensatory approaches such as emissions trading. They can either act by themselves or work with other companies, NGOs, or (local) governments.

  11. Declining uncertainty in transient climate response as CO2 forcing dominates future climate change

    NASA Astrophysics Data System (ADS)

    Myhre, Gunnar; Boucher, Olivier; Bréon, François-Marie; Forster, Piers; Shindell, Drew

    2015-03-01

    Carbon dioxide has exerted the largest portion of radiative forcing and surface temperature change over the industrial era, but other anthropogenic influences have also contributed. However, large uncertainties in total forcing make it difficult to derive climate sensitivity from historical observations. Anthropogenic forcing has increased between the Fourth and Fifth Assessment Reports of the Intergovernmental Panel of Climate Change (IPCC; refs , ), although its relative uncertainty has decreased. Here we show, based on data from the two reports, that this evolution towards lower uncertainty can be expected to continue into the future. Because it is easier to reduce air pollution than carbon dioxide emissions and because of the long lifetime of carbon dioxide, the less uncertain carbon dioxide forcing is expected to become increasingly dominant. Using a statistical model, we estimate that the relative uncertainty in anthropogenic forcing of more than 40% quoted in the latest IPCC report for 2011 will be almost halved by 2030, even without better scientific understanding. Absolute forcing uncertainty will also decline for the first time, provided projected decreases in aerosols occur. Other factors being equal, this stronger constraint on forcing will bring a significant reduction in the uncertainty of observation-based estimates of the transient climate response, with a 50% reduction in its uncertainty range expected by 2030.

  12. Continental weathering response to climate change: a modelling study (Invited)

    NASA Astrophysics Data System (ADS)

    Godderis, Y.; Williams, J. Z.; Schott, J.; Pollard, D.; Brantley, S. L.

    2009-12-01

    Chemical weathering is dependent on the climatic conditions, including air temperature and rainfall. Although obvious at the geological scale, this dependence has been recently evidenced at millenia to decadal timescales. In the present contribution, we explore the link between climate and weathering at these shorter timescales through numerical modelling. The rates of mineral weathering in loess deposited 23 ky ago in the Mississippi valley and experiencing soil formation for 10 ky are estimated using the WITCH model for weathering and the GENESIS model for climate simulation. The initial mineralogical composition of the loess is uniform along the Mississippi valley and mixes dolomite and alumino-silicates. Over the 10 kyr of the simulation, temperature at the soil surface is rising by up to 4°C, while the increase in the drainage of the loess section ranges from 10 to 40 % depending on the latitude of the simulated site. The calculated mineralogical evolution of the loess section is impacted, the main feature being the fast deepening of the dolomite weathering front by about 4 meters and the formation of a shallow plagioclase weathering front. The time evolution of the dissolved species production (hence the CO2 consumption) is calculated over the simulations. The exported dissolved silica output may rise by up to 25 %, but depends heavily on the latitude of the site. This coupled climatic-weathering study is then extended 200 years in the future to estimate the impact of the anthropogenic climate change on a weathering profile and on the CO2 consumption by weathering.

  13. Evolutionary and plastic responses to climate change in terrestrial plant populations

    PubMed Central

    Franks, Steven J; Weber, Jennifer J; Aitken, Sally N

    2014-01-01

    As climate change progresses, we are observing widespread changes in phenotypes in many plant populations. Whether these phenotypic changes are directly caused by climate change, and whether they result from phenotypic plasticity or evolution, are active areas of investigation. Here, we review terrestrial plant studies addressing these questions. Plastic and evolutionary responses to climate change are clearly occurring. Of the 38 studies that met our criteria for inclusion, all found plastic or evolutionary responses, with 26 studies showing both. These responses, however, may be insufficient to keep pace with climate change, as indicated by eight of 12 studies that examined this directly. There is also mixed evidence for whether evolutionary responses are adaptive, and whether they are directly caused by contemporary climatic changes. We discuss factors that will likely influence the extent of plastic and evolutionary responses, including patterns of environmental changes, species’ life history characteristics including generation time and breeding system, and degree and direction of gene flow. Future studies with standardized methodologies, especially those that use direct approaches assessing responses to climate change over time, and sharing of data through public databases, will facilitate better predictions of the capacity for plant populations to respond to rapid climate change. PMID:24454552

  14. The Water Volume Changes of Lake Manas and Its Response to Climate Change and Human Activities

    NASA Astrophysics Data System (ADS)

    Xu, Suning; Yang, Jingchun; Li, Youli

    2014-05-01

    The water volume changes of the lake basin in China's arid northwest region can sensitively reflect the impact of climate change and human activities in upper stream area. Lake Manas is a terminal lake of Manas Valley, a typical Valley in Northern Xinjiang. Just like other lakes, tectonic activities, such as water conservancy projects and agriculture irrigation projects, have great impacts on its evolution and change. We have a research on the response to climate change and human activities since 1950s, taking the Lake Manas for example. Collect aerial photographs and satellite imagery in year of 1958,1964,1979,1989,1999,2001,2003, with 1:50,000 topographic maps, 1:10000 DEM and other types of Figure and data of Lake Manas, we calculate the changes of the water volume of the Lake in 7different time period. According to the analysis of weather and hydrology records in the past 50 years, this author construct the correlation curves among the flow rate of Manas River, the temperature and precipitation in its upper steam area. This study shows that the development of contemporary Lake Manas could be divided to three stages: high-water period (in late the 1950s), extinct period (between 1970s and 1990s), and recovering season (in the early 21st century). The high-water period in late 1950s and the recovering season in early 21st century are mostly the results of excessive wet climate in the drainage basin, while the extinct period between the 1970s and the 1990s is mostly the result of man-made water projects in its upper stream area.The impact of climate change mainly in: the impact of climate change on runoff upstream determine the inflows of Lake Manas; the impact of downstream climate on the combination of water and heat determine the evaporation. The impact of human activities mainly in: the water conservancy projects upstream and agriculture irrigation projects since 1954 result in the extinct period between 1970s and 1990s in Lake Manas. Key Words: Lake Manas

  15. Beyond a warming fingerprint: individualistic biogeographic responses to heterogeneous climate change in California

    PubMed Central

    Rapacciuolo, Giovanni; Maher, Sean P; Schneider, Adam C; Hammond, Talisin T; Jabis, Meredith D; Walsh, Rachel E; Iknayan, Kelly J; Walden, Genevieve K; Oldfather, Meagan F; Ackerly, David D; Beissinger, Steven R

    2014-01-01

    Understanding recent biogeographic responses to climate change is fundamental for improving our predictions of likely future responses and guiding conservation planning at both local and global scales. Studies of observed biogeographic responses to 20th century climate change have principally examined effects related to ubiquitous increases in temperature – collectively termed a warming fingerprint. Although the importance of changes in other aspects of climate – particularly precipitation and water availability – is widely acknowledged from a theoretical standpoint and supported by paleontological evidence, we lack a practical understanding of how these changes interact with temperature to drive biogeographic responses. Further complicating matters, differences in life history and ecological attributes may lead species to respond differently to the same changes in climate. Here, we examine whether recent biogeographic patterns across California are consistent with a warming fingerprint. We describe how various components of climate have changed regionally in California during the 20th century and review empirical evidence of biogeographic responses to these changes, particularly elevational range shifts. Many responses to climate change do not appear to be consistent with a warming fingerprint, with downslope shifts in elevation being as common as upslope shifts across a number of taxa and many demographic and community responses being inconsistent with upslope shifts. We identify a number of potential direct and indirect mechanisms for these responses, including the influence of aspects of climate change other than temperature (e.g., the shifting seasonal balance of energy and water availability), differences in each taxon's sensitivity to climate change, trophic interactions, and land-use change. Finally, we highlight the need to move beyond a warming fingerprint in studies of biogeographic responses by considering a more multifaceted view of climate

  16. Beyond a warming fingerprint: individualistic biogeographic responses to heterogeneous climate change in California.

    PubMed

    Rapacciuolo, Giovanni; Maher, Sean P; Schneider, Adam C; Hammond, Talisin T; Jabis, Meredith D; Walsh, Rachel E; Iknayan, Kelly J; Walden, Genevieve K; Oldfather, Meagan F; Ackerly, David D; Beissinger, Steven R

    2014-09-01

    Understanding recent biogeographic responses to climate change is fundamental for improving our predictions of likely future responses and guiding conservation planning at both local and global scales. Studies of observed biogeographic responses to 20th century climate change have principally examined effects related to ubiquitous increases in temperature - collectively termed a warming fingerprint. Although the importance of changes in other aspects of climate - particularly precipitation and water availability - is widely acknowledged from a theoretical standpoint and supported by paleontological evidence, we lack a practical understanding of how these changes interact with temperature to drive biogeographic responses. Further complicating matters, differences in life history and ecological attributes may lead species to respond differently to the same changes in climate. Here, we examine whether recent biogeographic patterns across California are consistent with a warming fingerprint. We describe how various components of climate have changed regionally in California during the 20th century and review empirical evidence of biogeographic responses to these changes, particularly elevational range shifts. Many responses to climate change do not appear to be consistent with a warming fingerprint, with downslope shifts in elevation being as common as upslope shifts across a number of taxa and many demographic and community responses being inconsistent with upslope shifts. We identify a number of potential direct and indirect mechanisms for these responses, including the influence of aspects of climate change other than temperature (e.g., the shifting seasonal balance of energy and water availability), differences in each taxon's sensitivity to climate change, trophic interactions, and land-use change. Finally, we highlight the need to move beyond a warming fingerprint in studies of biogeographic responses by considering a more multifaceted view of climate

  17. The response of Lake Tahoe to climate change

    USGS Publications Warehouse

    Sahoo, G.B.; Schladow, S.G.; Reuter, J.E.; Coats, R.; Dettinger, M.; Riverson, J.; Wolfe, B.; Costa-Cabral, M.

    2013-01-01

    Meteorology is the driving force for lake internal heating, cooling, mixing, and circulation. Thus continued global warming will affect the lake thermal properties, water level, internal nutrient loading, nutrient cycling, food-web characteristics, fish-habitat, aquatic ecosystem, and other important features of lake limnology. Using a 1-D numerical model - the Lake Clarity Model (LCM) - together with the down-scaled climatic data of the two emissions scenarios (B1 and A2) of the Geophysical Fluid Dynamics Laboratory (GFDL) Global Circulation Model, we found that Lake Tahoe will likely cease to mix to the bottom after about 2060 for A2 scenario, with an annual mixing depth of less than 200 m as the most common value. Deep mixing, which currently occurs on average every 3-4 years, will (under the GFDL B1 scenario) occur only four times during 2061 to 2098. When the lake fails to completely mix, the bottom waters are not replenished with dissolved oxygen and eventually dissolved oxygen at these depths will be depleted to zero. When this occurs, soluble reactive phosphorus (SRP) and ammonium-nitrogen (both biostimulatory) are released from the deep sediments and contribute approximately 51 % and 14 % of the total SRP and dissolved inorganic nitrogen load, respectively. The lake model suggests that climate change will drive the lake surface level down below the natural rim after 2085 for the GFDL A2 but not the GFDL B1 scenario. The results indicate that continued climate changes could pose serious threats to the characteristics of the Lake that are most highly valued. Future water quality planning must take these results into account.

  18. Idiosyncratic responses of grizzly bear habitat to climate change based on projected food resource changes.

    PubMed

    Roberts, David R; Nielsen, Scott E; Stenhouse, Gordon B

    2014-07-01

    Climate change vulnerability assessments for species of conservation concern often use species distribution and ecological niche modeling to project changes in habitat. One of many assumptions of these approaches is that food web dependencies are consistent in time and environmental space. Species at higher trophic levels that rely on the availability of species at lower trophic levels as food may be sensitive to extinction cascades initiated by changes in the habitat of key food resources. Here we assess climate change vulnerability for Ursus arctos (grizzly bears) in the southern Canadian Rocky Mountains using projected changes to 17 of the most commonly consumed plant food items. We used presence-absence information from 7088 field plots to estimate ecological niches and to project changes in future distributions of each species. Model projections indicated idiosyncratic responses among food items. Many food items persisted or even increased, although several species were found to be vulnerable based on declines or geographic shifts in suitable habitat. These included Hedysarum alpinum (alpine sweet vetch), a critical spring and autumn root-digging resource when little else is available. Potential habitat loss was also identified for three fruiting species of lower importance to bears: Empetrum nigrum (crowberry), Vaccinium scoparium (grouseberry), and Fragaria virginiana (strawberry). A general trend towards uphill migration of bear foods may result in higher vulnerability to bear populations at low elevations, which are also those that are most likely to have human-bear conflict problems. Regardless, a wide diet breadth of grizzly bears, as well as wide environmental niches of most food items, make climate change a much lower threat to grizzly bears than other bear species such as polar bears and panda bears. We cannot exclude, however, future alterations in human behavior and land use resulting from climate change that may reduce survival rates. PMID:25154102

  19. Climate Change

    NASA Astrophysics Data System (ADS)

    Cowie, Jonathan

    2001-05-01

    In recent years climate change has become recognised as the foremost environmental problem of the twenty-first century. Not only will climate change potentially affect the multibillion dollar energy strategies of countries worldwide, but it also could seriously affect many species, including our own. A fascinating introduction to the subject, this textbook provides a broad review of past, present and likely future climate change from the viewpoints of biology, ecology and human ecology. It will be of interest to a wide range of people, from students in the life sciences who need a brief overview of the basics of climate science, to atmospheric science, geography, and environmental science students who need to understand the biological and human ecological implications of climate change. It will also be a valuable reference for those involved in environmental monitoring, conservation, policy-making and policy lobbying. The first book to cover not only the human impacts on climate, but how climate change will affect humans and the species that we rely on Written in an accessible style, with specialist terms used only when necessary and thoroughly explained The author has years of experience conveying the views of biological science learned societies to policy-makers

  20. Sustainable occupational responses to climate change through lifestyle choices.

    PubMed

    Hocking, Clare; Kroksmark, Ulla

    2013-03-01

    Abstract Occupational therapists and occupational scientists are increasingly aware of the relationship between occupation and global climate change, with some working to raise awareness of the issues and others proposing that an occupational perspective can make a valuable contribution to understanding and addressing the issues. In this discussion paper the United Nations Global Survey on Sustainable Lifestyles ( 1 ), which reports young adults' beliefs about everyday occupations that have a substantial impact on the environment (food, housekeeping, and transportation) is introduced. The authors argue that the survey findings are a valuable resource for occupational therapists who are concerned about global climate change and work with young adults (age 18-35), providing valuable insights into their concerns and preferences in relation to sustainability. To illustrate the insights contained in the reports, findings from four countries are presented: New Zealand and Sweden, the authors' countries of origin, and the Philippines and Lebanon which have people living in New Zealand and Sweden. Application to individual and community-based interventions to promote more sustainable lifestyles is suggested, along with studies to examine the perspectives of young adults with a disability, as their concerns and sustainability preferences might differ due to the barriers that limit their participation in educational and vocational occupations. PMID:23004010

  1. The Changing Climate.

    ERIC Educational Resources Information Center

    Schneider, Stephen H.

    1989-01-01

    Discusses the global change of climate. Presents the trend of climate change with graphs. Describes mathematical climate models including expressions for the interacting components of the ocean-atmosphere system and equations representing the basic physical laws governing their behavior. Provides three possible responses on the change. (YP)

  2. Watershed responses to climate change at Glacier National Park

    USGS Publications Warehouse

    Fagre, D.B.; Comanor, P.L.; White, J.D.; Hauer, F. Richard; Running, S.W.

    1997-01-01

    We have developed an approach which examines ecosystem function and the potential effects of climatic shifts. The Lake McDonald watershed of Glacier National Park was the focus for two linked research activities: acquisition of baseline data on hydrologic, chemical and aquatic organism attributes that characterize this pristine northern rocky mountain watershed, and further developing the Regional Hydro-Ecosystem Simulation System (RHESSys), a collection of integrated models which collectively provide spatially explicit, mechanistically-derived outputs of ecosystem processes, including hydrologic outflow, soil moisture, and snowpack water equivalence. In this unique setting field validation of RHESSys, outputs demonstrated that reasonable estimates of SWE and streamflow are being produced. RHESSys was used to predict annual stream discharge and temperature. The predictions, in conjunction with the field data, indicated that aquatic resources of the park may be significantly affected. Utilizing RHESSys to predict potential climate scenarios and response of other key ecosystem components can provide scientific insights as well as proactive guidelines for national park management.

  3. How do various maize crop models vary in their responses to climate change factors?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models give similar grain yield responses to changes in climatic factors, or whether they agr...

  4. RESPONSES AND FEEDBACK TO GLOBAL FORESTS TO CLIMATE CHANGE

    EPA Science Inventory

    The accumulation of greenhouse gases in the atmosphere over the past century is projected to cause a warming of the Earth. limate change predictions vary by region and terrestrial biosphere response and feedbacks will be ecosystem specific. orests play a major role in the earth's...

  5. Effective and responsible teaching of climate change in Earth Science-related disciplines

    NASA Astrophysics Data System (ADS)

    Robinson, Z. P.; Greenhough, B. J.

    2009-04-01

    Climate change is a core topic within Earth Science-related courses. This vast topic covers a wide array of different aspects that could be covered, from past climatic change across a vast range of scales to environmental (and social and economic) impacts of future climatic change and strategies for reducing anthropogenic climate change. The Earth Science disciplines play a crucial role in our understanding of past, present and future climate change and the Earth system in addition to understanding leading to development of strategies and technological solutions to achieve sustainability. However, an increased knowledge of the occurrence and causes of past (natural) climate changes can lead to a lessened concern and sense of urgency and responsibility amongst students in relation to anthropogenic causes of climatic change. Two concepts integral to the teaching of climate change are those of scientific uncertainty and complexity, yet an emphasis on these concepts can lead to scepticism about future predictions and a further loss of sense of urgency. The requirement to understand the nature of scientific uncertainty and think and move between different scales in particular relating an increased knowledge of longer timescale climatic change to recent (industrialised) climate change, are clearly areas of troublesome knowledge that affect students' sense of responsibility towards their role in achieving a sustainable society. Study of the attitudes of university students in a UK HE institution on a range of Earth Science-related programmes highlights a range of different attitudes in the student body towards the subject of climate change. Students express varied amounts of ‘climate change saturation' resulting from both media and curriculum coverage, a range of views relating to the significance of humans to the global climate and a range of opinions about the relevance of environmental citizenship to their degree programme. Climate change is therefore a challenging

  6. How does complex terrain influence responses of carbon and water cycle processes to climate variability and climate change?

    EPA Science Inventory

    We are pursuing the ambitious goal of understanding how complex terrain influences the responses of carbon and water cycle processes to climate variability and climate change. Our studies take place in H.J. Andrews Experimental Forest, an LTER (Long Term Ecological Research) site...

  7. Rapid genetic divergence in response to 15 years of simulated climate change.

    PubMed

    Ravenscroft, Catherine H; Whitlock, Raj; Fridley, Jason D

    2015-11-01

    Genetic diversity may play an important role in allowing individual species to resist climate change, by permitting evolutionary responses. Our understanding of the potential for such responses to climate change remains limited, and very few experimental tests have been carried out within intact ecosystems. Here, we use amplified fragment length polymorphism (AFLP) data to assess genetic divergence and test for signatures of evolutionary change driven by long-term simulated climate change applied to natural grassland at Buxton Climate Change Impacts Laboratory (BCCIL). Experimental climate treatments were applied to grassland plots for 15 years using a replicated and spatially blocked design and included warming, drought and precipitation treatments. We detected significant genetic differentiation between climate change treatments and control plots in two coexisting perennial plant study species (Festuca ovina and Plantago lanceolata). Outlier analyses revealed a consistent signature of selection associated with experimental climate treatments at individual AFLP loci in P. lanceolata, but not in F. ovina. Average background differentiation at putatively neutral AFLP loci was close to zero, and genomewide genetic structure was associated neither with species abundance changes (demography) nor with plant community-level responses to long-term climate treatments. Our results demonstrate genetic divergence in response to a suite of climatic environments in reproductively mature populations of two perennial plant species and are consistent with an evolutionary response to climatic selection in P. lanceolata. These genetic changes have occurred in parallel with impacts on plant community structure and may have contributed to the persistence of individual species through 15 years of simulated climate change at BCCIL. PMID:26311135

  8. Non-linearity dynamics in ecosystem response to climate change: Case studies and policy implications

    USGS Publications Warehouse

    Burkett, V.R.; Wilcox, D.A.; Stottlemyer, R.; Barrow, W.; Fagre, D.; Baron, J.; Nielsen, J.L.; Allen, C.D.; Peterson, D.L.; Ruggerone, G.; Doyle, T.

    2005-01-01

    Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate cna lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear.

  9. Nonlinear dynamics in ecosystem response to climatic change: Case studies and policy implications

    USGS Publications Warehouse

    Burkett, Virginia R.; Wilcox, Douglas A.; Stottlemyer, Robert; Barrow, Wylie; Fagre, Dan; Baron, Jill; Price, Jeff; Nielsen, Jennifer L.; Allen, Craig D.; Peterson, David L.; Ruggerone, Greg; Doyle, Thomas

    2005-01-01

    Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear.

  10. Global reductions in seafloor biomass in response to climate change

    PubMed Central

    Jones, Daniel O B; Yool, Andrew; Wei, Chih-Lin; Henson, Stephanie A; Ruhl, Henry A; Watson, Reg A; Gehlen, Marion

    2014-01-01

    Seafloor organisms are vital for healthy marine ecosystems, contributing to elemental cycling, benthic remineralization, and ultimately sequestration of carbon. Deep-sea life is primarily reliant on the export flux of particulate organic carbon from the surface ocean for food, but most ocean biogeochemistry models predict global decreases in export flux resulting from 21st century anthropogenically induced warming. Here we show that decadal-to-century scale changes in carbon export associated with climate change lead to an estimated 5.2% decrease in future (2091–2100) global open ocean benthic biomass under RCP8.5 (reduction of 5.2 Mt C) compared with contemporary conditions (2006–2015). Our projections use multi-model mean export flux estimates from eight fully coupled earth system models, which contributed to the Coupled Model Intercomparison Project Phase 5, that have been forced by high and low representative concentration pathways (RCP8.5 and 4.5, respectively). These export flux estimates are used in conjunction with published empirical relationships to predict changes in benthic biomass. The polar oceans and some upwelling areas may experience increases in benthic biomass, but most other regions show decreases, with up to 38% reductions in parts of the northeast Atlantic. Our analysis projects a future ocean with smaller sized infaunal benthos, potentially reducing energy transfer rates though benthic multicellular food webs. More than 80% of potential deep-water biodiversity hotspots known around the world, including canyons, seamounts, and cold-water coral reefs, are projected to experience negative changes in biomass. These major reductions in biomass may lead to widespread change in benthic ecosystems and the functions and services they provide. PMID:24382828

  11. Global reductions in seafloor biomass in response to climate change.

    PubMed

    Jones, Daniel O B; Yool, Andrew; Wei, Chih-Lin; Henson, Stephanie A; Ruhl, Henry A; Watson, Reg A; Gehlen, Marion

    2014-06-01

    Seafloor organisms are vital for healthy marine ecosystems, contributing to elemental cycling, benthic remineralization, and ultimately sequestration of carbon. Deep-sea life is primarily reliant on the export flux of particulate organic carbon from the surface ocean for food, but most ocean biogeochemistry models predict global decreases in export flux resulting from 21st century anthropogenically induced warming. Here we show that decadal-to-century scale changes in carbon export associated with climate change lead to an estimated 5.2% decrease in future (2091-2100) global open ocean benthic biomass under RCP8.5 (reduction of 5.2 Mt C) compared with contemporary conditions (2006-2015). Our projections use multi-model mean export flux estimates from eight fully coupled earth system models, which contributed to the Coupled Model Intercomparison Project Phase 5, that have been forced by high and low representative concentration pathways (RCP8.5 and 4.5, respectively). These export flux estimates are used in conjunction with published empirical relationships to predict changes in benthic biomass. The polar oceans and some upwelling areas may experience increases in benthic biomass, but most other regions show decreases, with up to 38% reductions in parts of the northeast Atlantic. Our analysis projects a future ocean with smaller sized infaunal benthos, potentially reducing energy transfer rates though benthic multicellular food webs. More than 80% of potential deep-water biodiversity hotspots known around the world, including canyons, seamounts, and cold-water coral reefs, are projected to experience negative changes in biomass. These major reductions in biomass may lead to widespread change in benthic ecosystems and the functions and services they provide. PMID:24382828

  12. Response of Glaciers to Climate Change in Northwest China

    NASA Astrophysics Data System (ADS)

    Li, Z.; Wang, P.

    2015-12-01

    In Northwest China, an extremely dry region, more than 20,000 mountain glaciers are developed. Glacial melt water is vital for local water resources, ecosystem in the lower reaches, peoples' living and city development there. During the past several decades, due to climate warming, the most glaciers in NW China are in a state of rapid retreating. To obtain the general idea on response of glaciers in that region, Tianshan Glaciological Station, Chinese Academy of Sciences selected more than ten glaciers in six sub-regions along Altai Mountain, Tianshan and Qilian Mountain, respectively, doing in-situ observations. Based on field observation and remote sensing technique, this study has revealed that the area reductions in different regions range between 8.8%~34.2 % during the past four decades. The potential impact of the glacier recession on water resource in future will be spatially different. For the Tarim River, the glacier runoff is estimated to maintain its current level or increase somewhat in next 30~50 years. In the north slope of Tianshan, the glaciers with a size smaller than 1 km2 are most likely to be melted away in next 20~40 years, and those larger than 5 km2 are melting intensively. In eastern Xinjiang, because the number of the glaciers is small and also because the climate is extremely dry, the glacier retreating are causing the water shortage problem. For Ili River and Irtysh River, because they are dominant by snow melt runoff, the impact of the glacier shrinkage and temperature rise would be limited on the quantity of the river runoff, but significant on the annual distribution of the river runoff. For Qilian Mountains, glaciers are quite small. The vanishing of small glacier will have significant impact on local water resources in near future.

  13. Changing Stomatal Conductance in Response to Anthropogenic Climate Change: a Model-Data Comparison

    NASA Astrophysics Data System (ADS)

    Purcell, C.; Batke, S.; Caballero, R.; McElwain, J.

    2015-12-01

    Understanding the response of stomatal conductance to increasing anthropogenic CO2 is of critical importance for the evaluation of the global hydrological cycle, and has implications for future climate change, particularly flood and risk. Via physiological and morphological changes in leaf structure, stomatal conductance has been shown to decrease under elevated CO2 conditions, stimulating higher vegetation water use efficiency and water retention within the land system. However, an assessment of how the simulation of changing stomatal conductance in an Earth System Model compares with observational data under varying CO2 concentrations (Free Air CO2 Enrichment - FACE - studies) has not yet been conducted, and is crucial for considering the significance of the issue of flooding for global policy making. Here we utilise the Community Land Model, Version 4.5 (CLM4.5), performing climate simulations over a range of atmospheric CO2 concentrations from 350ppm to 700ppm (50ppm increments), and compare the model data with results from a conclusive set of FACE studies (350ppm - 700ppm range). We show general agreement between the climate model and FACE data with regards to decreasing stomatal conductance in response to increasing CO2 concentration. However the magnitudes of the conductance changes differ, spatially within the model, and across species in the FACE studies. We show how the model can be used to assess global stomatal conductance changes on spatial scales where FACE cannot (ie. most FACE studies are located across the 30°- 60° latitude belt). This is useful for understanding the role of groundwater retention and potential flood risk at regional scales across the globe. Additionally the model demonstrates seasonal-spatial changes in stomatal conductance in response to CO2 forcing. Such seasonal changes are generally absent throughout FACE studies, as measurement is predominantly tasked during summer months. Our results reiterate the importance of climate

  14. The role of science assessments in policy making in response to climatic change

    SciTech Connect

    Jager, J.

    1996-12-31

    The paper traces three scientific debates on issues related to anthropogenic climate change: the introduction of non-CO{sub 2} greenhouse gases into assessments; the assessment of the climate sensitivity; and the changing evaluations of the risk of sea-level rise. These stories illustrate how science assessments affected the perceived urgency of the response as well as showing the nature of climate change assessments and the role they have played in developing a policy response to climatic change. Looking at major assessments of the magnitude and timing of the potential climatic change also gives clear indications of factors that contribute to a successful scientific assessment. These factors include broad international participation, careful preparation of peer-reviewed executive summaries and the avoidance of parallel assessments which require input from one another. The material presented in this paper is based on the output from a major international project on Social Learning in the Management of Global Environmental Risks.

  15. Trends in Global Vegetation Activity and Climatic Drivers Indicate a Decoupled Response to Climate Change.

    PubMed

    Schut, Antonius G T; Ivits, Eva; Conijn, Jacob G; Ten Brink, Ben; Fensholt, Rasmus

    2015-01-01

    Detailed understanding of a possible decoupling between climatic drivers of plant productivity and the response of ecosystems vegetation is required. We compared trends in six NDVI metrics (1982-2010) derived from the GIMMS3g dataset with modelled biomass productivity and assessed uncertainty in trend estimates. Annual total biomass weight (TBW) was calculated with the LINPAC model. Trends were determined using a simple linear regression, a Thiel-Sen medium slope and a piecewise regression (PWR) with two segments. Values of NDVI metrics were related to Net Primary Production (MODIS-NPP) and TBW per biome and land-use type. The simple linear and Thiel-Sen trends did not differ much whereas PWR increased the fraction of explained variation, depending on the NDVI metric considered. A positive trend in TBW indicating more favorable climatic conditions was found for 24% of pixels on land, and for 5% a negative trend. A decoupled trend, indicating positive TBW trends and monotonic negative or segmented and negative NDVI trends, was observed for 17-36% of all productive areas depending on the NDVI metric used. For only 1-2% of all pixels in productive areas, a diverging and greening trend was found despite a strong negative trend in TBW. The choice of NDVI metric used strongly affected outcomes on regional scales and differences in the fraction of explained variation in MODIS-NPP between biomes were large, and a combination of NDVI metrics is recommended for global studies. We have found an increasing difference between trends in climatic drivers and observed NDVI for large parts of the globe. Our findings suggest that future scenarios must consider impacts of constraints on plant growth such as extremes in weather and nutrient availability to predict changes in NPP and CO2 sequestration capacity. PMID:26466347

  16. Trends in Global Vegetation Activity and Climatic Drivers Indicate a Decoupled Response to Climate Change

    PubMed Central

    Schut, Antonius G. T.; Ivits, Eva; Conijn, Jacob G.; ten Brink, Ben; Fensholt, Rasmus

    2015-01-01

    Detailed understanding of a possible decoupling between climatic drivers of plant productivity and the response of ecosystems vegetation is required. We compared trends in six NDVI metrics (1982–2010) derived from the GIMMS3g dataset with modelled biomass productivity and assessed uncertainty in trend estimates. Annual total biomass weight (TBW) was calculated with the LINPAC model. Trends were determined using a simple linear regression, a Thiel-Sen medium slope and a piecewise regression (PWR) with two segments. Values of NDVI metrics were related to Net Primary Production (MODIS-NPP) and TBW per biome and land-use type. The simple linear and Thiel-Sen trends did not differ much whereas PWR increased the fraction of explained variation, depending on the NDVI metric considered. A positive trend in TBW indicating more favorable climatic conditions was found for 24% of pixels on land, and for 5% a negative trend. A decoupled trend, indicating positive TBW trends and monotonic negative or segmented and negative NDVI trends, was observed for 17–36% of all productive areas depending on the NDVI metric used. For only 1–2% of all pixels in productive areas, a diverging and greening trend was found despite a strong negative trend in TBW. The choice of NDVI metric used strongly affected outcomes on regional scales and differences in the fraction of explained variation in MODIS-NPP between biomes were large, and a combination of NDVI metrics is recommended for global studies. We have found an increasing difference between trends in climatic drivers and observed NDVI for large parts of the globe. Our findings suggest that future scenarios must consider impacts of constraints on plant growth such as extremes in weather and nutrient availability to predict changes in NPP and CO2 sequestration capacity. PMID:26466347

  17. Climate change: present and future risks to health, and necessary responses.

    PubMed

    McMichael, A J; Lindgren, E

    2011-11-01

    Recent observed changes in Earth's climate, to which humans have contributed substantially, are affecting various health outcomes. These include altered distributions of some infectious disease vectors (ticks at high latitudes, malaria mosquitoes at high altitudes), and an uptrend in extreme weather events and associated deaths, injuries and other health outcomes. Future climate change, if unchecked, will have increasing, mostly adverse, health impacts - both direct and indirect. Climate change will amplify health problems in vulnerable regions, influence infectious disease emergence, affect food yields and nutrition, increase risks of climate-related disasters and impair mental health. The health sector should assist society understand the risks to health and the needed responses. PMID:21682780

  18. Morphological variation in salamanders and their potential response to climate change

    PubMed Central

    Ficetola, Gentile Francesco; Colleoni, Emiliano; Renaud, Julien; Scali, Stefano; Padoa-Schioppa, Emilio; Thuiller, Wilfried

    2016-01-01

    Despite the recognition that some species might quickly adapt to new conditions under climate change, demonstrating and predicting such a fundamental response is challenging. Morphological variations in response to climate may be caused by evolutionary changes or phenotypic plasticity, or both, but teasing apart these processes is difficult. Here we built on the number of thoracic vertebrae (NTV) in ectothermic vertebrates, a known genetically-based feature, to establish a link with body size and evaluate how climate change might affect the future morphological response of this group of species. First we show that in old-world salamanders, NTV variation is strongly related to changes in body size. Secondly, using 22 salamander species as a case study, we found support for relationships between the spatial variation in selected bioclimatic variables and NTV for most of species. For 44% of species, precipitation and aridity were the predominant drivers of geographical variation of the NTV. Temperature features were dominant for 31% of species, while for 19% temperature and precipitation played a comparable role. This two-step analysis demonstrates that ectothermic vertebrates may evolve in response to climate change by modifying the number of thoracic vertebrae. These findings allow to develop scenarios for potential morphological evolution under future climate change, and to identify areas and species in which the most marked evolutionary responses are expected. Resistance to climate change estimated from species distribution models was positively related to present-day species morphological response, suggesting that the ability of morphological evolution may play a role for species’ persistence under climate change. The possibility that present-day capacity for local adaptation might help the resistance response to climate change can be integrated into analyses of the impact of global changes, and should also be considered when planning management actions

  19. Morphological variation in salamanders and their potential response to climate change.

    PubMed

    Ficetola, Gentile Francesco; Colleoni, Emiliano; Renaud, Julien; Scali, Stefano; Padoa-Schioppa, Emilio; Thuiller, Wilfried

    2016-06-01

    Despite the recognition that some species might quickly adapt to new conditions under climate change, demonstrating and predicting such a fundamental response is challenging. Morphological variations in response to climate may be caused by evolutionary changes or phenotypic plasticity, or both, but teasing apart these processes is difficult. Here, we built on the number of thoracic vertebrae (NTV) in ectothermic vertebrates, a known genetically based feature, to establish a link with body size and evaluate how climate change might affect the future morphological response of this group of species. First, we show that in old-world salamanders, NTV variation is strongly related to changes in body size. Secondly, using 22 salamander species as a case study, we found support for relationships between the spatial variation in selected bioclimatic variables and NTV for most of species. For 44% of species, precipitation and aridity were the predominant drivers of geographical variation of the NTV. Temperature features were dominant for 31% of species, while for 19% temperature and precipitation played a comparable role. This two-step analysis demonstrates that ectothermic vertebrates may evolve in response to climate change by modifying the number of thoracic vertebrae. These findings allow to develop scenarios for potential morphological evolution under future climate change and to identify areas and species in which the most marked evolutionary responses are expected. Resistance to climate change estimated from species distribution models was positively related to present-day species morphological response, suggesting that the ability of morphological evolution may play a role for species' persistence under climate change. The possibility that present-day capacity for local adaptation might help the resistance response to climate change can be integrated into analyses of the impact of global changes and should also be considered when planning management actions favouring

  20. 77 FR 19661 - Draft National Water Program 2012 Strategy: Response to Climate Change

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... AGENCY Draft National Water Program 2012 Strategy: Response to Climate Change AGENCY: Environmental... of water resource management, including how to: address risks to drinking water, wastewater and storm water infrastructure; protect quality of surface water, ground water and drinking water;...

  1. Is Dealing with Climate Change a Corporation’s Responsibility? A Social Contract Perspective

    PubMed Central

    Unsworth, Kerrie L.; Russell, Sally V.; Davis, Matthew C.

    2016-01-01

    In this paper, we argue that individuals – as members of society – play an important role in the expectations of whether or not companies are responsible for addressing environmental issues, and whether or not governments should regulate them. From this perspective of corporate social responsibility as a social contract we report the results of a survey of 1066 individuals. The aim of the survey was to assess participants’ belief in anthropogenic climate change, free-market ideology, and beliefs around who is responsible for dealing with climate change. Results showed that both climate change views and free market ideology have a strong effect on beliefs that companies are responsible for dealing with climate change and on support for regulatory policy to that end. Furthermore, we found that free market ideology is a barrier in the support of corporate regulatory policy. The implications of these findings for research, policy, and practice are discussed. PMID:27588009

  2. Is Dealing with Climate Change a Corporation's Responsibility? A Social Contract Perspective.

    PubMed

    Unsworth, Kerrie L; Russell, Sally V; Davis, Matthew C

    2016-01-01

    In this paper, we argue that individuals - as members of society - play an important role in the expectations of whether or not companies are responsible for addressing environmental issues, and whether or not governments should regulate them. From this perspective of corporate social responsibility as a social contract we report the results of a survey of 1066 individuals. The aim of the survey was to assess participants' belief in anthropogenic climate change, free-market ideology, and beliefs around who is responsible for dealing with climate change. Results showed that both climate change views and free market ideology have a strong effect on beliefs that companies are responsible for dealing with climate change and on support for regulatory policy to that end. Furthermore, we found that free market ideology is a barrier in the support of corporate regulatory policy. The implications of these findings for research, policy, and practice are discussed. PMID:27588009

  3. Climatic effects of 1950-2050 changes in US anthropogenic aerosols - Part 2: Climate response

    NASA Astrophysics Data System (ADS)

    Leibensperger, E. M.; Mickley, L. J.; Jacob, D. J.; Chen, W.-T.; Seinfeld, J. H.; Nenes, A.; Adams, P. J.; Streets, D. G.; Kumar, N.; Rind, D.

    2012-04-01

    We investigate the climate response to changing US anthropogenic aerosol sources over the 1950-2050 period by using the NASA GISS general circulation model (GCM) and comparing to observed US temperature trends. Time-dependent aerosol distributions are generated from the GEOS-Chem chemical transport model applied to historical emission inventories and future projections. Radiative forcing from US anthropogenic aerosols peaked in 1970-1990 and has strongly declined since due to air quality regulations. We find that the regional radiative forcing from US anthropogenic aerosols elicits a strong regional climate response, cooling the central and eastern US by 0.5-1.0 °C on average during 1970-1990, with the strongest effects on maximum daytime temperatures in summer and autumn. Aerosol cooling reflects comparable contributions from direct and indirect (cloud-mediated) radiative effects. Absorbing aerosol (mainly black carbon) has negligible warming effect. Aerosol cooling reduces surface evaporation and thus decreases precipitation along the US east coast, but also increases the southerly flow of moisture from the Gulf of Mexico resulting in increased cloud cover and precipitation in the central US. Observations over the eastern US show a lack of warming in 1960-1980 followed by very rapid warming since, which we reproduce in the GCM and attribute to trends in US anthropogenic aerosol sources. Present US aerosol concentrations are sufficiently low that future air quality improvements are projected to cause little further warming in the US (0.1 °C over 2010-2050). We find that most of the warming from aerosol source controls in the US has already been realized over the 1980-2010 period.

  4. Heating up Climate Literacy Education: Understanding Teachers' and Students' Motivational and Affective Response to Climate Change

    NASA Astrophysics Data System (ADS)

    Sinatra, G. M.

    2011-12-01

    Changing students' ideas about controversial scientific issues, such as human-induced climate change, presents unique challenges for educators (Lombardi & Sinatra, 2010; Sinatra & Mason, 2008). First, climate science is complex and requires "systems thinking," or the ability to think and reason abstractly about emergent systems (Goldstone & Sakamoto, 2003). Appreciating the intricacies of complex systems and emergent processes has proven challenging for students (Chi, 2005). In addition to these challenges, there are specific misconceptions that may lead thinking astray on the issue of global climate change, such as the distinction between weather and climate (Lombardi & Sinatra, 2010). As an example, when students are asked about their views on climate change, they often recall individual storm events or very cold periods and use their personal experiences and recollections of short-term temperature fluctuations to assess whether the planet is warming. Beyond the conceptual difficulties, controversial topics offer another layer of challenge. Such topics are often embedded in complex socio-cultural and political contexts, have a high degree of uncertainty, and may be perceived by individuals as in conflict with their personal or religious beliefs (Levinson, 2006, Sinatra, Kardash, Taasoobshirazi, & Lombardi, 2011). Individuals are often committed to their own views on socio-scientific issues and this commitment may serve as a motivation to actively resist new ideas (Dole & Sinatra, 1998). Individuals may also have strong emotions associated with their misconceptions (Broughton, Pekrun, & Sinatra, 2011). Negative emotions, misconceptions, and resistance do not make a productive combination for learning. Further, teachers who find human-induced climate change implausible have been shown to hold negative emotions about having to teach about climate change (Lombardi & Sinatra, in preparation), which could affect how they present the topic to students. In this

  5. Ecological and methodological drivers of species' distribution and phenology responses to climate change.

    PubMed

    Brown, Christopher J; O'Connor, Mary I; Poloczanska, Elvira S; Schoeman, David S; Buckley, Lauren B; Burrows, Michael T; Duarte, Carlos M; Halpern, Benjamin S; Pandolfi, John M; Parmesan, Camille; Richardson, Anthony J

    2016-04-01

    Climate change is shifting species' distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global data set of 651 published marine species' responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that (1) reanalyses of existing time series state how the existing data sets may limit the inferences about possible climate responses; (2) qualitative comparisons of species' responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates; and (4) that new time series be designed to include the detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the accuracy

  6. Neotropical vegetation responses to Younger Dryas climates as analogs for future climate change scenarios and lessons for conservation

    NASA Astrophysics Data System (ADS)

    Rull, V.; Vegas-Vilarrúbia, T.; Montoya, E.

    2015-05-01

    The Younger Dryas (YD) climatic reversal (12.86-11.65 cal ky BP), especially the warming initiated at ∼12.6 cal ky BP, and the associated vegetation changes have been proposed as past analogs to forecast the potential vegetation responses to future global warming. In this paper, we applied this model to highland and midland Neotropical localities. We used pollen analysis of lake sediments to record vegetation responses to YD climatic changes, which are reconstructed from independent paleoclimatic proxies such as the Mg/Ca ratio on foraminiferal tests and Equilibrium Line Altitude (ELA) for paleotemperature, and grayscale density and Titanium content for paleoprecipitation. Paleoclimatic reconstructions at both highlands and midlands showed a clear YD signal with a conspicuous warming extending into the early Holocene. A small percentage of taxa resulted to be sensitive to these YD climate changes. Response lags were negligible at the resolution of the study. However, changes in the sensitive taxa were relevant enough to determine changes in biodiversity and taxonomic composition. Highland vegetation experienced mainly intra-community reorganizations, whereas midland vegetation underwent major changes leading to community substitutions. This was explained in terms of threshold-crossing non-linear responses in which the coupling of climatic and other forcings (fire) was proposed as the main driving mechanism. Paleoecology provides meaningful insights on the responses of highland and midland Neotropical vegetation to the YD climatic reversal. Biotic responses at both individual (species) and collective (assemblage) levels showed patterns and processes of vegetation change useful to understand its ecological dynamics, as well as the mechanisms and external drivers involved. The use of paleoecological methods to document the biotic responses to the YD climate shifts can be useful to help forecasting the potential consequences of future global warming. Due to its quasi

  7. Separating the role of biotic interactions and climate in determining adaptive response of plants to climate change.

    PubMed

    Tomiolo, Sara; Van der Putten, Wim H; Tielbörger, Katja

    2015-05-01

    Altered rainfall regimes will greatly affect the response of plant species to climate change. However, little is known about how direct effects of changing precipitation on plant performance may depend on other abiotic factors and biotic interactions. We used reciprocal transplants between climatically very different sites with simultaneous manipulation of soil, plant population origin, and neighbor conditions to evaluate local adaptation and possible adaptive response of four Eastern Mediterranean annual plant species to climate change. The effect of site on plant performance was negligible, but soil origin had a strong effect on fecundity, most likely due to differential water retaining ability. Competition by neighbors strongly reduced fitness. We separated the effects of the abiotic and biotic soil properties on plant performance by repeating the field experiment in a greenhouse under homogenous environmental conditions and including a soil biota manipulation treatment. As in the field, plant performance differed among soil origins and neighbor treatments. Moreover, we found plant species-specific responses to soil biota that may be best explained by the differential sensitivity to negative and positive soil biota effects. Overall, under the conditions of our experiment with two contrasting sites, biotic interactions had a strong effect on plant fitness that interacted with and eventually overrode climate. Because climate and biotic interactions covary, reciprocal transplants and climate gradient studies should consider soil biotic interactions and abiotic conditions when evaluating climate change effects on plant performance. PMID:26236843

  8. Predicting Climate Change using Response Theory: Global Averages and Spatial Patterns

    NASA Astrophysics Data System (ADS)

    Lucarini, Valerio; Lunkeit, Frank; Ragone, Francesco

    2016-04-01

    The provision of accurate methods for predicting the climate response to anthropogenic and natural forcings is a key contemporary scientific challenge. Using a simplified and efficient open-source climate model featuring O(105) degrees of freedom, we show how it is possible to approach such a problem using nonequilibrium statistical mechanics. Using the theoretical framework of the pullback attractor and the tools of response theory we propose a simple yet efficient method for predicting - at any lead time and in an ensemble sense - the change in climate properties resulting from increase in the concentration of CO2 using test perturbation model runs. We assess strengths and limitations of the response theory in predicting the changes in the globally averaged values of surface temperature and of the yearly total precipitation, as well as their spatial patterns. We also show how it is possible to define accurately concepts like the the inertia of the climate system or to predict when climate change is detectable given a scenario of forcing. Our analysis can be extended for dealing with more complex portfolios of forcings and can be adapted to treat, in principle, any climate observable. Our conclusion is that climate change is indeed a problem that can be effectively seen through a statistical mechanical lens, and that there is great potential for optimizing the current coordinated modelling exercises run for the preparation of the subsequent reports of the Intergovernmental Panel for Climate Change.

  9. Contrasting response of South Greenland glaciers to recent climatic change

    SciTech Connect

    Warren, C.R.; Glasser, N.F. )

    1992-05-01

    A unique geographical configuration of glaciers exists in the Narsarsuaq district of South Greenland. Two large outlet glaciers divide into seven distributaries, such that each glacier system has land-terminating, tidewater-calving, and fresh-water-calving termini. Despite a similar climatic regime, these seven glaciers have exhibited strongly contrasting terminal behavior in historical time, as shown by historical records, aerial photographs, and fieldwork in 1989. The behavior of the calving glaciers cannot be accounted for with reference solely to climatic parameters. The combination of iceberg calving dynamics and topographic control has partially decoupled them from climatic forcing such that their oscillations relate more closely to glaciodynamic than glacioclimatic factors.

  10. Climatology of Andean glaciers: A framework to understand glacier response to climate change

    NASA Astrophysics Data System (ADS)

    Sagredo, E. A.; Lowell, T. V.

    2012-04-01

    Recent glacial and climate models suggest that glaciers located in contrasting climates could respond with different magnitudes to identical climatic perturbations. This implies that to understand the response of glaciers to a particular climate perturbation or to compare glacial fluctuations between different regions, climate conditions that permit glaciers to exist must be taken into account. In this study we systematize, classify, and identify the spatial distribution of the climates that permit the occurrence of present-day glaciers in the climatically diverse Andes. A first approximation suggests that a sample of 234 Andean glaciers exist under three distinctive combinations of temperature and precipitation conditions: i) cold and dry, ii) intermediate, and iii) warm and wet conditions. Cluster analysis (CA) and Principal Component analysis (PCA) of temperature, precipitation, and humidity reveal seven climatic configurations that support present-day Andean glaciers and suggest that these configurations have a distinctive geographical distribution. The groups are: 1) inner tropics and Tierra del Fuego, 2) wetter outer tropics, 3) drier outer tropics, 4) subtropics, 5) central Chile-Argentina (semi-arid), 6) northern and central Patagonia, and 7) southern Patagonia. This classification provides a basis to examine the spatial variability of glacier sensitivity to climate change, to unravel the causes of past glacial fluctuations, to understand the climatic signals driving present-day glacier fluctuations, and perhaps to predict the response of glaciers to future climate changes.

  11. Threshold effects in the vegetation response to Holocene climate changes in central Asia

    NASA Astrophysics Data System (ADS)

    Zhao, Y.

    2015-12-01

    Understanding the response of ecosystems to past climate is critical for evaluating the impacts of future climate changes. A relatively abrupt vegetation shift in response to the late Holocene gradual climate changes has been well documented for the Sahara-Sahel ecosystem. However, whether such threshold shift is of universal significance remains to be further addressed. Here, we examine the vegetation-climate relationships in central Asia based on four newly recovered Holocene pollen records and a synthesis on previously published pollen data. The results show that the orbital-induced gradual climate trend during the Holocene led to two major abrupt vegetation shifts, and that the timings of these shifts are highly dependent of the local rainfall conditions. Instead, the mid-Holocene vegetation remained rather stable despite of the changing climate. These new findings demonstrate generally significant threshold and truncation effects of climate changes on vegetation, as are strongly supported by surface pollen data and LPJ-GUESS modeling. The results also imply that using pollen data to reconstruct past climate changes is not always straightforward. Our findings have important implication for understanding the potential effects of global warming on dryland ecosystem change.

  12. Exploring the southern ocean response to climate change

    NASA Technical Reports Server (NTRS)

    Martinson, Douglas G.; Rind, David; Parkinson, Claire

    1993-01-01

    The purpose of this project was to couple a regional (Southern Ocean) ocean/sea ice model to the existing Goddard Institute for Space Science (GISS) atmospheric general circulation model (GCM). This modification recognizes: the relative isolation of the Southern Ocean; the need to account, prognostically, for the significant air/sea/ice interaction through all involved components; and the advantage of translating the atmospheric lower boundary (typically the rapidly changing ocean surface) to a level that is consistent with the physical response times governing the system evolution (that is, to the base of the fast responding ocean surface layer). The deeper ocean beneath this layer varies on time scales several orders of magnitude slower than the atmosphere and surface ocean, and therefore the boundary between the upper and deep ocean represents a more reasonable fixed boundary condition.

  13. Forest Owners' Response to Climate Change: University Education Trumps Value Profile

    PubMed Central

    Persson, Erik; Hanewinkel, Marc

    2016-01-01

    Do forest owners’ levels of education or value profiles explain their responses to climate change? The cultural cognition thesis (CCT) has cast serious doubt on the familiar and often criticized "knowledge deficit" model, which says that laypeople are less concerned about climate change because they lack scientific knowledge. Advocates of CCT maintain that citizens with the highest degrees of scientific literacy and numeracy are not the most concerned about climate change. Rather, this is the group in which cultural polarization is greatest, and thus individuals with more limited scientific literacy and numeracy are more concerned about climate change under certain circumstances than those with higher scientific literacy and numeracy. The CCT predicts that cultural and other values will trump the positive effects of education on some forest owners' attitudes to climate change. Here, using survey data collected in 2010 from 766 private forest owners in Sweden and Germany, we provide the first evidence that perceptions of climate change risk are uncorrelated with, or sometimes positively correlated with, education level and can be explained without reference to cultural or other values. We conclude that the recent claim that advanced scientific literacy and numeracy polarizes perceptions of climate change risk is unsupported by the forest owner data. In neither of the two countries was university education found to reduce the perception of risk from climate change. Indeed in most cases university education increased the perception of risk. Even more importantly, the effect of university education was not dependent on the individuals' value profile. PMID:27223473

  14. Forest Owners' Response to Climate Change: University Education Trumps Value Profile.

    PubMed

    Blennow, Kristina; Persson, Johannes; Persson, Erik; Hanewinkel, Marc

    2016-01-01

    Do forest owners' levels of education or value profiles explain their responses to climate change? The cultural cognition thesis (CCT) has cast serious doubt on the familiar and often criticized "knowledge deficit" model, which says that laypeople are less concerned about climate change because they lack scientific knowledge. Advocates of CCT maintain that citizens with the highest degrees of scientific literacy and numeracy are not the most concerned about climate change. Rather, this is the group in which cultural polarization is greatest, and thus individuals with more limited scientific literacy and numeracy are more concerned about climate change under certain circumstances than those with higher scientific literacy and numeracy. The CCT predicts that cultural and other values will trump the positive effects of education on some forest owners' attitudes to climate change. Here, using survey data collected in 2010 from 766 private forest owners in Sweden and Germany, we provide the first evidence that perceptions of climate change risk are uncorrelated with, or sometimes positively correlated with, education level and can be explained without reference to cultural or other values. We conclude that the recent claim that advanced scientific literacy and numeracy polarizes perceptions of climate change risk is unsupported by the forest owner data. In neither of the two countries was university education found to reduce the perception of risk from climate change. Indeed in most cases university education increased the perception of risk. Even more importantly, the effect of university education was not dependent on the individuals' value profile. PMID:27223473

  15. Determining the response of African biota to climate change: using the past to model the future

    PubMed Central

    Willis, K. J.; Bennett, K. D.; Burrough, S. L.; Macias-Fauria, M.; Tovar, C.

    2013-01-01

    Prediction of biotic responses to future climate change in tropical Africa tends to be based on two modelling approaches: bioclimatic species envelope models and dynamic vegetation models. Another complementary but underused approach is to examine biotic responses to similar climatic changes in the past as evidenced in fossil and historical records. This paper reviews these records and highlights the information that they provide in terms of understanding the local- and regional-scale responses of African vegetation to future climate change. A key point that emerges is that a move to warmer and wetter conditions in the past resulted in a large increase in biomass and a range distribution of woody plants up to 400–500 km north of its present location, the so-called greening of the Sahara. By contrast, a transition to warmer and drier conditions resulted in a reduction in woody vegetation in many regions and an increase in grass/savanna-dominated landscapes. The rapid rate of climate warming coming into the current interglacial resulted in a dramatic increase in community turnover, but there is little evidence for widespread extinctions. However, huge variation in biotic response in both space and time is apparent with, in some cases, totally different responses to the same climatic driver. This highlights the importance of local features such as soils, topography and also internal biotic factors in determining responses and resilience of the African biota to climate change, information that is difficult to obtain from modelling but is abundant in palaeoecological records. PMID:23878343

  16. Time-lag effects of global vegetation responses to climate change.

    PubMed

    Wu, Donghai; Zhao, Xiang; Liang, Shunlin; Zhou, Tao; Huang, Kaicheng; Tang, Bijian; Zhao, Wenqian

    2015-09-01

    Climate conditions significantly affect vegetation growth in terrestrial ecosystems. Due to the spatial heterogeneity of ecosystems, the vegetation responses to climate vary considerably with the diverse spatial patterns and the time-lag effects, which are the most important mechanism of climate-vegetation interactive effects. Extensive studies focused on large-scale vegetation-climate interactions use the simultaneous meteorological and vegetation indicators to develop models; however, the time-lag effects are less considered, which tends to increase uncertainty. In this study, we aim to quantitatively determine the time-lag effects of global vegetation responses to different climatic factors using the GIMMS3g NDVI time series and the CRU temperature, precipitation, and solar radiation datasets. First, this study analyzed the time-lag effects of global vegetation responses to different climatic factors. Then, a multiple linear regression model and partial correlation model were established to statistically analyze the roles of different climatic factors on vegetation responses, from which the primary climate-driving factors for different vegetation types were determined. The results showed that (i) both the time-lag effects of the vegetation responses and the major climate-driving factors that significantly affect vegetation growth varied significantly at the global scale, which was related to the diverse vegetation and climate characteristics; (ii) regarding the time-lag effects, the climatic factors explained 64% variation of the global vegetation growth, which was 11% relatively higher than the model ignoring the time-lag effects; (iii) for the area with a significant change trend (for the period 1982-2008) in the global GIMMS3g NDVI (P < 0.05), the primary driving factor was temperature; and (iv) at the regional scale, the variation in vegetation growth was also related to human activities and natural disturbances. Considering the time-lag effects is quite

  17. Climate variability slows evolutionary responses of Colias butterflies to recent climate change.

    PubMed

    Kingsolver, Joel G; Buckley, Lauren B

    2015-03-01

    How does recent climate warming and climate variability alter fitness, phenotypic selection and evolution in natural populations? We combine biophysical, demographic and evolutionary models with recent climate data to address this question for the subalpine and alpine butterfly, Colias meadii, in the southern Rocky Mountains. We focus on predicting patterns of selection and evolution for a key thermoregulatory trait, melanin (solar absorptivity) on the posterior ventral hindwings, which affects patterns of body temperature, flight activity, adult and egg survival, and reproductive success in Colias. Both mean annual summer temperatures and thermal variability within summers have increased during the past 60 years at subalpine and alpine sites. At the subalpine site, predicted directional selection on wing absorptivity has shifted from generally positive (favouring increased wing melanin) to generally negative during the past 60 years, but there is substantial variation among years in the predicted magnitude and direction of selection and the optimal absorptivity. The predicted magnitude of directional selection at the alpine site declined during the past 60 years and varies substantially among years, but selection has generally been positive at this site. Predicted evolutionary responses to mean climate warming at the subalpine site since 1980 is small, because of the variability in selection and asymmetry of the fitness function. At both sites, the predicted effects of adaptive evolution on mean population fitness are much smaller than the fluctuations in mean fitness due to climate variability among years. Our analyses suggest that variation in climate within and among years may strongly limit evolutionary responses of ectotherms to mean climate warming in these habitats. PMID:25631995

  18. Climate variability slows evolutionary responses of Colias butterflies to recent climate change

    PubMed Central

    Kingsolver, Joel G.; Buckley, Lauren B.

    2015-01-01

    How does recent climate warming and climate variability alter fitness, phenotypic selection and evolution in natural populations? We combine biophysical, demographic and evolutionary models with recent climate data to address this question for the subalpine and alpine butterfly, Colias meadii, in the southern Rocky Mountains. We focus on predicting patterns of selection and evolution for a key thermoregulatory trait, melanin (solar absorptivity) on the posterior ventral hindwings, which affects patterns of body temperature, flight activity, adult and egg survival, and reproductive success in Colias. Both mean annual summer temperatures and thermal variability within summers have increased during the past 60 years at subalpine and alpine sites. At the subalpine site, predicted directional selection on wing absorptivity has shifted from generally positive (favouring increased wing melanin) to generally negative during the past 60 years, but there is substantial variation among years in the predicted magnitude and direction of selection and the optimal absorptivity. The predicted magnitude of directional selection at the alpine site declined during the past 60 years and varies substantially among years, but selection has generally been positive at this site. Predicted evolutionary responses to mean climate warming at the subalpine site since 1980 is small, because of the variability in selection and asymmetry of the fitness function. At both sites, the predicted effects of adaptive evolution on mean population fitness are much smaller than the fluctuations in mean fitness due to climate variability among years. Our analyses suggest that variation in climate within and among years may strongly limit evolutionary responses of ectotherms to mean climate warming in these habitats. PMID:25631995

  19. Modeling the response of plants and ecosystems to elevated CO sub 2 and climate change

    SciTech Connect

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  20. Modeling the response of plants and ecosystems to elevated CO{sub 2} and climate change

    SciTech Connect

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth`s surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society`s ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  1. Dealing with uncertainty: Response-resilient climate change mitigation polices for long-lived and short-lived climate pollutants

    NASA Astrophysics Data System (ADS)

    Millar, R.; Boneham, J.; Hepburn, C.; Allen, M. R.

    2015-12-01

    Climate change solutions are subject to many inherent uncertainties. One of the most important is the uncertainty over the magnitude of the physical response of the climate system to external forcing. The risk of extremely large responses to forcing, so called "fat-tail" outcomes, cannot be ruled out from the latest science and offer profound challenges when creating policies that aim to meet a specific target of global temperature change. This study offers examples of how mitigation policies can be made resilient to this uncertainty in the physical climate response via indexing policies against an attributable anthropogenic warming index (the magnitude of the observed global mean warming that is can be traced to human activities), the AWI, instead of against time directly. We show that indexing policy measures that influence the total stock of carbon in the atmosphere (such as the fraction of extracted carbon sequestered) against the AWI can largely eliminate the risk of missing the specified warming goal due to unexpectedly large climate responses as well as the risk of costly over-mitigation if the physical response turned out to be lower than expected. We offer further examples of how this methodology can be expanded to include short-lived climate pollutants as well as long-lived carbon dioxide. Indexing policies against the AWI can have important consequences for the actions of governments acting to design national climate mitigation policies as well as private sector investors looking to incentivise the transition to a climate-stable economy. We conclude with some thoughts on how these indexes can help focus attention on the long-term perspective that is consistent with the conclusions of the latest climate science on what is required to ultimately stabilise the global climate system.

  2. Watershed response and land energy feedbacks under climate change depend upon groundwater.

    SciTech Connect

    Maxwell, R M; Kollet, S J

    2008-06-10

    Human induced climate change will have a significant impact on the hydrologic cycle, creating changes in fresh water resources, land cover, and feedbacks that are difficult to characterize, which makes it an issue of global importance. Previous studies have not included subsurface storage in climate change simulations and feedbacks. A variably-saturated groundwater flow model with integrated overland flow and land surface model processes is used to examine the interplay between coupled water and energy processes under climate change conditions. A case study from the Southern Great Plains (SGP) USA, an important agricultural region that is susceptible to drought, is used as the basis for three scenarios simulations using a modified atmospheric forcing dataset to reflect predicted effects due to human-induced climate change. These scenarios include an increase in the atmospheric temperature and variations in rainfall amount and are compared to the present-day climate case. Changes in shallow soil saturation and groundwater levels are quantified as well as the corresponding energy fluxes at the land surface. Here we show that groundwater and subsurface lateral flow processes are critical in understanding hydrologic response and energy feedbacks to climate change and that certain regions are more susceptible to changes in temperature, while others to changes in precipitation. This groundwater control is critical for understanding recharge and drought processes, possible under future climate conditions.

  3. Body size and activity times mediate mammalian responses to climate change.

    PubMed

    McCain, Christy M; King, Sarah R B

    2014-06-01

    Model predictions of extinction risks from anthropogenic climate change are dire, but still overly simplistic. To reliably predict at-risk species we need to know which species are currently responding, which are not, and what traits are mediating the responses. For mammals, we have yet to identify overarching physiological, behavioral, or biogeographic traits determining species' responses to climate change, but they must exist. To date, 73 mammal species in North America and eight additional species worldwide have been assessed for responses to climate change, including local extirpations, range contractions and shifts, decreased abundance, phenological shifts, morphological or genetic changes. Only 52% of those species have responded as expected, 7% responded opposite to expectations, and the remaining 41% have not responded. Which mammals are and are not responding to climate change is mediated predominantly by body size and activity times (phylogenetic multivariate logistic regressions, P < 0.0001). Large mammals respond more, for example, an elk is 27 times more likely to respond to climate change than a shrew. Obligate diurnal and nocturnal mammals are more than twice as likely to respond as mammals with flexible activity times (P < 0.0001). Among the other traits examined, species with higher latitudinal and elevational ranges were more likely to respond to climate change in some analyses, whereas hibernation, heterothermy, burrowing, nesting, and study location did not influence responses. These results indicate that some mammal species can behaviorally escape climate change whereas others cannot, analogous to paleontology's climate sheltering hypothesis. Including body size and activity flexibility traits into future extinction risk forecasts should substantially improve their predictive utility for conservation and management. PMID:24449019

  4. Integrating human responses to climate change into conservation vulnerability assessments and adaptation planning.

    PubMed

    Maxwell, Sean L; Venter, Oscar; Jones, Kendall R; Watson, James E M

    2015-10-01

    The impact of climate change on biodiversity is now evident, with the direct impacts of changing temperature and rainfall patterns and increases in the magnitude and frequency of extreme events on species distribution, populations, and overall ecosystem function being increasingly publicized. Changes in the climate system are also affecting human communities, and a range of human responses across terrestrial and marine realms have been witnessed, including altered agricultural activities, shifting fishing efforts, and human migration. Failing to account for the human responses to climate change is likely to compromise climate-smart conservation efforts. Here, we use a well-established conservation planning framework to show how integrating human responses to climate change into both species- and site-based vulnerability assessments and adaptation plans is possible. By explicitly taking into account human responses, conservation practitioners will improve their evaluation of species and ecosystem vulnerability, and will be better able to deliver win-wins for human- and biodiversity-focused climate adaptation. PMID:26555860

  5. Changes in Climate over the South China Sea and Adjacent Regions: Response to and Feedback on Global Climate Change

    NASA Astrophysics Data System (ADS)

    Yang, Song

    2016-04-01

    El Niño-Southern Oscillation and the Asian monsoon have experienced significant long-term changes in the past decades. These changes, together with other factors, have in turn led to large climate change signals over the South China Sea and adjacent regions including Southeast Asia, the western Pacific, and the tropical Indian Ocean. An attribution analysis of the feedback processes of these signals indicate the predominant importance of water vapor and cloud radiative feedbacks. Experiments with multiple earth system models also show that these regional climate change signals exert significant influences on global climate. The increases in atmospheric heating over Southeast Asia and sea surface temperature in the adjacent oceans in the past decades have weakened the Indian and African monsoons, led to a drying effect over East Asia, and generated wave-train patterns in both the northern and southern hemispheres, explaining several prominent climate features in and outside Southeast Asia.

  6. Evolutionary and plastic responses of freshwater invertebrates to climate change: realized patterns and future potential.

    PubMed

    Stoks, Robby; Geerts, Aurora N; De Meester, Luc

    2014-01-01

    We integrated the evidence for evolutionary and plastic trait changes in situ in response to climate change in freshwater invertebrates (aquatic insects and zooplankton). The synthesis on the trait changes in response to the expected reductions in hydroperiod and increases in salinity indicated little evidence for adaptive, plastic, and genetic trait changes and for local adaptation. With respect to responses to temperature, there are many studies on temporal trait changes in phenology and body size in the wild that are believed to be driven by temperature increases, but there is a general lack of rigorous demonstration whether these trait changes are genetically based, adaptive, and causally driven by climate change. Current proof for genetic trait changes under climate change in freshwater invertebrates stems from a limited set of common garden experiments replicated in time. Experimental thermal evolution experiments and common garden warming experiments associated with space-for-time substitutions along latitudinal gradients indicate that besides genetic changes, also phenotypic plasticity and evolution of plasticity are likely to contribute to the observed phenotypic changes under climate change in aquatic invertebrates. Apart from plastic and genetic thermal adjustments, also genetic photoperiod adjustments are widespread and may even dominate the observed phenological shifts. PMID:24454547

  7. Responses of Terrestrial Ecosystems’ Net Primary Productivity to Future Regional Climate Change in China

    PubMed Central

    Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

    2013-01-01

    The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems’ response to global climate change. China’s ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund–Potsdam–Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China’s terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change. PMID:23593325

  8. Evolution of plant–pollinator mutualisms in response to climate change

    PubMed Central

    Gilman, R Tucker; Fabina, Nicholas S; Abbott, Karen C; Rafferty, Nicole E

    2012-01-01

    Climate change has the potential to desynchronize the phenologies of interdependent species, with potentially catastrophic effects on mutualist populations. Phenologies can evolve, but the role of evolution in the response of mutualisms to climate change is poorly understood. We developed a model that explicitly considers both the evolution and the population dynamics of a plant–pollinator mutualism under climate change. How the populations evolve, and thus whether the populations and the mutualism persist, depends not only on the rate of climate change but also on the densities and phenologies of other species in the community. Abundant alternative mutualist partners with broad temporal distributions can make a mutualism more robust to climate change, while abundant alternative partners with narrow temporal distributions can make a mutualism less robust. How community composition and the rate of climate change affect the persistence of mutualisms is mediated by two-species Allee thresholds. Understanding these thresholds will help researchers to identify those mutualisms at highest risk owing to climate change. PMID:25568025

  9. High-latitude tree-ring data: Records of climatic change and ecological response

    SciTech Connect

    Graumlich, L.J.

    1992-03-01

    Tree-ring data provide critical information regarding two fundamental questions as to the role of the polar regions in global change: (1) what is the nature of climatic variability; and (2) what is the response of vegetation to climatic variability. Tree-ring based climatic reconstructions document the variability of the climate system on time scales of years to centuries. Dendroclimatic reconstructions indicate that the climatic episodes defined on the basis of documentary evidence in western Europe (i.e., Medieval Warm Episode, ca. A.D. 1000-1300; Little Ice Age, ca. A.D. 15501850) can be observed at some high-latitude sites (ex., Polar Urals). Spatial variation in long-term temperature trends (ex., northern Fennoscandia vs Polar Urals) demonstrates the importance of regional-scale climatic controls. When collated into global networks, proxy-based climatic reconstructions can be used to test hypotheses as to the relative importance of external forcing vs. internal variation in governing climatic variation. Specifically, such a global network would allow the quantification of the climatic response to various permutations of factors thought to be important in governing decadal- to centennial-scale climatic variation (i.e., solar insolation, volcanic activity, trace gas concentrations)

  10. Assessing insect responses to climate change: What are we testing for? Where should we be heading?

    PubMed

    Andrew, Nigel R; Hill, Sarah J; Binns, Matthew; Bahar, Md Habibullah; Ridley, Emma V; Jung, Myung-Pyo; Fyfe, Chris; Yates, Michelle; Khusro, Mohammad

    2013-01-01

    To understand how researchers are tackling globally important issues, it is crucial to identify whether current research is comprehensive enough to make substantive predictions about general responses. We examined how research on climate change affecting insects is being assessed, what factors are being tested and the localities of studies, from 1703 papers published between 1985 and August 2012. Most published research (64%) is generated from Europe and North America and being dedicated to core data analysis, with 29% of the studies analysed dedicated to Lepidoptera and 22% Diptera: which are well above their contribution to the currently identified insect species richness (estimated at 13% and 17% respectively). Research publications on Coleoptera fall well short of their proportional contribution (19% of publications but 39% of insect species identified), and to a lesser extent so do Hemiptera, and Hymenoptera. Species specific responses to changes in temperature by assessing distribution/range shifts or changes in abundance were the most commonly used methods of assessing the impact of climate change on insects. Research on insects and climate change to date is dominated by manuscripts assessing butterflies in Europe, insects of economic and/or environmental concern in forestry, agriculture, and model organisms. The research on understanding how insects will respond to a rapidly changing climate is still in its infancy, but the current trends of publications give a good basis for how we are attempting to assess insect responses. In particular, there is a crucial need for broader studies of ecological, behavioural, physiological and life history responses to be addressed across a greater range of geographic locations, particularly Asia, Africa and Australasia, and in areas of high human population growth and habitat modification. It is still too early in our understanding of taxa responses to climate change to know if charismatic taxa, such as butterflies, or

  11. Intensification of winter transatlantic aviation turbulence in response to climate change

    NASA Astrophysics Data System (ADS)

    Williams, Paul D.; Joshi, Manoj M.

    2013-07-01

    Atmospheric turbulence causes most weather-related aircraft incidents. Commercial aircraft encounter moderate-or-greater turbulence tens of thousands of times each year worldwide, injuring probably hundreds of passengers (occasionally fatally), costing airlines tens of millions of dollars and causing structural damage to planes. Clear-air turbulence is especially difficult to avoid, because it cannot be seen by pilots or detected by satellites or on-board radar. Clear-air turbulence is linked to atmospheric jet streams, which are projected to be strengthened by anthropogenic climate change. However, the response of clear-air turbulence to projected climate change has not previously been studied. Here we show using climate model simulations that clear-air turbulence changes significantly within the transatlantic flight corridor when the concentration of carbon dioxide in the atmosphere is doubled. At cruise altitudes within 50-75°N and 10-60°W in winter, most clear-air turbulence measures show a 10-40% increase in the median strength of turbulence and a 40-170% increase in the frequency of occurrence of moderate-or-greater turbulence. Our results suggest that climate change will lead to bumpier transatlantic flights by the middle of this century. Journey times may lengthen and fuel consumption and emissions may increase. Aviation is partly responsible for changing the climate, but our findings show for the first time how climate change could affect aviation.

  12. Favorable climate change response explains non-native species' success in Thoreau's woods.

    PubMed

    Willis, Charles G; Ruhfel, Brad R; Primack, Richard B; Miller-Rushing, Abraham J; Losos, Jonathan B; Davis, Charles C

    2010-01-01

    Invasive species have tremendous detrimental ecological and economic impacts. Climate change may exacerbate species invasions across communities if non-native species are better able to respond to climate changes than native species. Recent evidence indicates that species that respond to climate change by adjusting their phenology (i.e., the timing of seasonal activities, such as flowering) have historically increased in abundance. The extent to which non-native species success is similarly linked to a favorable climate change response, however, remains untested. We analyzed a dataset initiated by the conservationist Henry David Thoreau that documents the long-term phenological response of native and non-native plant species over the last 150 years from Concord, Massachusetts (USA). Our results demonstrate that non-native species, and invasive species in particular, have been far better able to respond to recent climate change by adjusting their flowering time. This demonstrates that climate change has likely played, and may continue to play, an important role in facilitating non-native species naturalization and invasion at the community level. PMID:20126652

  13. Sex-specific responses to climate change in plants alter population sex ratio and performance.

    PubMed

    Petry, William K; Soule, Judith D; Iler, Amy M; Chicas-Mosier, Ana; Inouye, David W; Miller, Tom E X; Mooney, Kailen A

    2016-07-01

    Males and females are ecologically distinct in many species, but whether responses to climate change are sex-specific is unknown. We document sex-specific responses to climate change in the plant Valeriana edulis (valerian) over four decades and across its 1800-meter elevation range. Increased elevation was associated with increased water availability and female frequency, likely owing to sex-specific water use efficiency and survival. Recent aridification caused male frequency to move upslope at 175 meters per decade, a rate of trait shift outpacing reported species' range shifts by an order of magnitude. This increase in male frequency reduced pollen limitation and increased seedset. Coupled with previous studies reporting sex-specific arthropod communities, these results underscore the importance of ecological differences between the sexes in mediating biological responses to climate change. PMID:27365446

  14. The Response of Vegetation Zonation in Rocky Mountain Ecotones to Climate Change

    NASA Astrophysics Data System (ADS)

    Foster, A.; Shuman, J. K.; Shugart, H. H., Jr.

    2014-12-01

    Mean annual temperatures in the western United States have increased in the last few decades, and during the 21st century, it is predicted that this warming trend will continue. This change in climate may create shifts in the optimal ranges of vegetation within the Rocky Mountains, requiring species migration. For a species at the top of a mountain there may be little room for upward migration. These forests are a crucial part of the US's carbon budget, thus it is important to analyze how climate change will affect the zonation and species composition of vegetation in Rocky Mountain landscapes. UVAFME is an individual-based gap model that simulates biomass and species composition of a forest. Originally developed for northeast China and applied across all of Russia, this model has accurately simulated diverse forests in a range of climates, as well as the response of these forests to climate change. UVAFME is first calibrated to several sites along the Colorado and Wyoming Rocky Mountains using species, soil, and climate data from the US Forest Service. The initial model output of biomass and species composition is tested against forest inventory data and expected forest type ecotone along an elevational gradient. The model is then run with a linear increase in temperature of 3°C over 200 years, corresponding to the A1B IPPC climate scenario. These results are compared to current forest inventory data and to model runs without climate change. We project that with climate change species ranges will shift up the mountain, leading to an increase in the deciduous species Populus tremuloides, and a decrease in coniferous species at high elevations. These results are an important step in evaluating the response of Rocky Mountain vegetation to climate change and will help predict the future of these crucial ecosystems.

  15. Response of western mountain ecosystems to climatic variability and change: the Western Mountain Initiative

    USGS Publications Warehouse

    Stephenson, Nathan L.; Peterson, Dave; Fagre, Daniel B.; Allen, Craig D.; McKenzie, Donald; Baron, Jill S.; O'Brian, Kelly

    2007-01-01

    Mountain ecosystems within our national parks and other protected areas provide valuable goods and services such as clean water, biodiversity conservation, and recreational opportunities, but their potential responses to expected climatic changes are inadequately understood. The Western Mountain Initiative (WMI) is a collaboration of scientists whose research focuses on understanding and predicting responses of western mountain ecosystems to climatic variability and change. It is a legacy of the Global Change Research Program initiated by the National Park Service (NPS) in 1991 and continued by the U.S. Geological Survey (USGS) to this day as part of the U.S. Climate Change Science Program (http://www.climatescience.gov/). All WMI scientists are active participants in CIRMOUNT, and seek to further its goals.

  16. Response of western mountain ecosystems to climatic variability and change: The Western Mountain Initiative

    USGS Publications Warehouse

    Stephenson, Nathan L.; Peterson, David A.; Fagre, Daniel B.; Allen, Craig; McKenzie, Donald; Baron, Jill; O'Brien, K.

    2006-01-01

    Mountain ecosystems within our national parks and other protected areas provide valuable goods and services such as clean water, biodiversity conservation, and recreational opportunities, but their potential responses to expected climatic changes are inadequately understood. The Western Mountain Initiative (WMI) is a collaboration of scientists whose research focuses on understanding and predicting responses of western mountain ecosystems to climatic variability and change. It is a legacy of the Global Change Research Program initiated by the National Park Service (NPS) in 1991 and continued by the U.S. Geological Survey (USGS) to this day as part of the U.S. Climate Change Science Program (http://www.climatescience.gov/). All WMI scientists are active participants in CIRMOUNT, and seek to further its goals.

  17. Agroecology: Implications for plant response to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural ecosystems (agroecosystems) represent the balance between the physiological responses of plants and plant canopies and the energy exchanges. Rising temperature and increasing CO2 coupled with an increase in variability of precipitation will create a complex set of interactions on plant ...

  18. Modeling phenological responses of Inner Mongolia grassland species to regional climate change

    NASA Astrophysics Data System (ADS)

    Li, Qiuyue; Xu, Lin; Pan, Xuebiao; Zhang, Lizhen; Li, Chao; Yang, Ning; Qi, Jiaguo

    2016-01-01

    Plant phenology is an important indicator of ecosystem dynamics and services. However, little is understood of its responses to climate change, particularly in ecologically sensitive regions such as arid and semi-arid grasslands. In this study, we analyzed a long-term climate and plant phenology dataset of thirteen grassland species in the Inner Mongolia of China, collected during 1981-2011 time period, to understand temporal patterns of plant phenology and then developed a simple chilling-adjusted physiological model to simulate phenological responses of each plant species to climate change. The results of regional climate analysis suggested that the minimum temperature was increasing at a greater rate than mean and maximum temperatures in the region and the climate variability had significant impacts on vegetation phenology. Chilling from an early stage in spring in general slowed down the phenological development in most plant species, although there were some inconsistencies among sites and years. Specifically, we found lower precipitation during green-up resulted in delayed flowering, which may attribute to plant self-adjustment strategy to respond changes in climate. These climate dependent phenologies were characterized by a simple physiological model. Scenario analysis suggested that by 2071-2100 significant shifts in plant phenology are expected in Inner Mongolia, including as much as 6-11 days earlier in green-up time and 8-11 days shorter in growing season due to earlier senescence.

  19. Crop Models, CO2, and Climate Change - Response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our research article did not criticize the design of models used to predict global change impacts on future food supply. We argued that reliable model projections require accurate model parameterization. Data from the fully open-air field treatments with elevated CO2 (FACE) indicate that the commonl...

  20. Predicting Climate Change Using Response Theory: Global Averages and Spatial Patterns

    NASA Astrophysics Data System (ADS)

    Lucarini, Valerio; Ragone, Francesco; Lunkeit, Frank

    2016-04-01

    The provision of accurate methods for predicting the climate response to anthropogenic and natural forcings is a key contemporary scientific challenge. Using a simplified and efficient open-source general circulation model of the atmosphere featuring O(10^5 ) degrees of freedom, we show how it is possible to approach such a problem using nonequilibrium statistical mechanics. Response theory allows one to practically compute the time-dependent measure supported on the pullback attractor of the climate system, whose dynamics is non-autonomous as a result of time-dependent forcings. We propose a simple yet efficient method for predicting—at any lead time and in an ensemble sense—the change in climate properties resulting from increase in the concentration of CO_2 using test perturbation model runs. We assess strengths and limitations of the response theory in predicting the changes in the globally averaged values of surface temperature and of the yearly total precipitation, as well as in their spatial patterns. The quality of the predictions obtained for the surface temperature fields is rather good, while in the case of precipitation a good skill is observed only for the global average. We also show how it is possible to define accurately concepts like the inertia of the climate system or to predict when climate change is detectable given a scenario of forcing. Our analysis can be extended for dealing with more complex portfolios of forcings and can be adapted to treat, in principle, any climate observable. Our conclusion is that climate change is indeed a problem that can be effectively seen through a statistical mechanical lens, and that there is great potential for optimizing the current coordinated modelling exercises run for the preparation of the subsequent reports of the Intergovernmental Panel for Climate Change.

  1. U.S. and Chinese Scientists Discuss the Ocean's Response to Climate Change

    NASA Astrophysics Data System (ADS)

    DiMarco, Steven F.; Wu, Dexing

    2009-04-01

    Climate Change and Coastal Oceans Workshop; Qingdao, China, 26-28 October 2008; A 3-day workshop was held in China to discuss coastal ocean processes, the biogeochemistry of large river-dominated ocean margins (RiOMars), and climate change and variability studies; to formulate a strategy for a joint venture to assess how climate change has affected coastal oceans; and to predict the ocean's response to future change scenarios. The workshop, which brought together experts from Texas A&M University (TAMU) and five Chinese universities and institutes—Ocean University of China (OUC), Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), Xiamen University (XU), Tianjin University of Science and Technology (TUST), and East China Normal University (ECNU), highlighted the similarities in topics important to North America and Asia. As indicated by the 2007 Intergovernmental Panel on Climate Change report, climate change imposes far-reaching challenges on society. This workshop focused on two large, river-dominated coastal environments: the Mississippi-Atchafalaya system and the Changjiang estuary. Numerous parallels exist between the impacts of the Changjiang on the East China Sea and the Mississippi on the Gulf of Mexico. These RiOMars are ideal for examining the impacts of climate change because they are characterized by large, heavily populated watersheds in two countries that are important in determining the human carbon footprint. The hydrology, biodiversity, and geochemical characteristics of these systems have been greatly influenced by land use and regional-scale climate change. Workshop participants reviewed current progress in understanding physical and biogeochemical processes controlling the two RiOMars, brainstormed challenges in developing a multidisciplinary system capable of assessing and predicting impacts of global climate change on these RiOMars, and identified a multifaceted approach to address these challenges.

  2. Herders' perceptions of and responses to climate change in northern Pakistan.

    PubMed

    Joshi, S; Jasra, W A; Ismail, M; Shrestha, R M; Yi, S L; Wu, N

    2013-09-01

    Migratory pastoralism is an adaptation to a harsh and unstable environment, and pastoral herders have traditionally adapted to environmental and climatic change by building on their in-depth knowledge of this environment. In the Hindu Kush Himalayan region, and particularly in the arid and semiarid areas of northern Pakistan, pastoralism, the main livelihood, is vulnerable to climate change. Little detailed information is available about climate trends and impacts in remote mountain regions; herders' perceptions of climate change can provide the information needed by policy makers to address problems and make decisions on adaptive strategies in high pastoral areas. A survey was conducted in Gilgit-Baltistan province of Pakistan to assess herders' perceptions of, and adaptation strategies to climate change. Herders' perceptions were gathered in individual interviews and focus group discussions. The herders perceived a change in climate over the past 10-15 years with longer and more intense droughts in summer, more frequent and heavier snowfall in winter, and prolonged summers and relatively shorter winters. These perceptions were validated by published scientific evidence. The herders considered that the change in climate had directly impacted pastures and then livestock by changing vegetation composition and reducing forage yield. They had adopted some adaptive strategies in response to the change such as altering the migration pattern and diversifying livelihoods. The findings show that the herder communities have practical lessons and indigenous knowledge related to rangeland management and adaptation to climate change that should be shared with the scientific community and integrated into development planning. PMID:23674240

  3. Holocene Climate and Catchment-Specific Responses to Climate Change, Recorded in a Transect of Icelandic Lakes

    NASA Astrophysics Data System (ADS)

    Geirsdottir, A.; Axford, Y.; Florian, C. R.; Miller, G. H.; Crump, S. E.; Larsen, D. J.; Olafsdóttir, S.; Thordarson, T.; Blair, C.

    2015-12-01

    Holocene paleoclimate reconstructions from the northern North Atlantic landmasses exhibit greater responses to climate forcings than other Arctic regions presumably tied to changes in North Atlantic ocean-atmosphere circulation. Here we present an overview of high-resolution, precisely dated and PSV synchronized Holocene lake sediment records on Iceland, where we employ diverse proxies at sites spanning a broad modern climate gradient, from the presently glaciated highlands to the coastal lowlands. Despite substantial differences in catchment specific processes that influence each lake record, the multi-proxy reconstructions over the last 10 ka show remarkably consistent trends, especially throughout the mid to late Holocene cooling related to the slow decrease in summer insolation. Of particular note are highly non-linear abrupt departures of centennial scale summer cold periods such as at 5.5 ka, ~4.2 ka; ~3.0 ka, ~1.5 ka, 0.7 ka, and 0.2 ka. Some of the abrupt shifts may be related to Icelandic volcanism influencing catchment stability, but the lack of a full recovery to pre-existing values after the perturbation suggests increased periglacial activity, decreased vegetation cover, and glacier growth in Iceland. That these shifts reflect regional climate changes is also supported by contemporaneous shifts documented elsewhere in the northern North Atlantic region. Although timing and abruptness of these shifts is similar between our Icelandic lake records, their magnitude can differ substantially. Regional-scale factors such as volcanism likely modulate climatic responses to radiative forcing; and at the same time, local watershed characteristics like vegetation cover and soil properties produce site-specific environmental responses to climate change. Our Icelandic lake records provide opportunities to observe the precise timing of local climate shifts and corresponding environmental responses, and thus to disentangle these effects.

  4. Responses to historical climate change identify contemporary threats to diversity in Dodecatheon

    PubMed Central

    Oberle, Brad; Schaal, Barbara A.

    2011-01-01

    Anthropogenic climate change may threaten many species with extinction. However, species at risk today survived global climate change in recent geological history. Describing how habitat tracking and adaptation allowed species to survive warming since the end of the Pleistocene can indicate the relative importance of dispersal and natural selection during climate change. By taking this historical perspective, we can identify how contemporary climate change could interfere with these mechanisms and threaten the most vulnerable species. We focused on a group of closely related plant species in the genus Dodecatheon (Primulaceae) in eastern North America. Two rare species (Dodecatheon amethystinum and Dodecatheon frenchii) that are endemic to patchy cool cliffs may be glacial relicts whose ranges constricted following the last glacial maximum. Alternatively, these species may be extreme ecotypes of a single widespread species (Dodecatheon meadia) that quickly adapted to microclimatic differences among habitats. We test support for these alternative scenarios by combining ecophysiological and population genetic data at a regional scale. An important ecophysiological trait distinguishes rare species from D. meadia, but only a few northern populations of D. amethystinum are genetically distinctive. These relict populations indicate that habitat tracking did occur with historical climate change. However, relatively stronger evidence for isolation by distance and admixture suggests that local adaptation and genetic introgression have been at least as important. The complex response of Dodecatheon to historical climate change suggests that contemporary conservation efforts should accommodate evolutionary processes, in some cases by restoring genetic connectivity between ecologically differentiated populations. PMID:21402919

  5. Notable shifting in the responses of vegetation activity to climate change in China

    NASA Astrophysics Data System (ADS)

    Chen, Aifang; He, Bin; Wang, Honglin; Huang, Ling; Zhu, Yunhua; Lv, Aifeng

    The weakening relationship between inter-annual temperature variability and vegetation activity in the Northern Hemisphere over the last three decades has been reported by a recent study. However, how and to what extent vegetation activity responds to climate change in China is still unclear. We applied the Pearson correlation and partial correlation methods with a moving 15-y window to the GIMMS NDVI dataset from NOAA/AVHRR and observed climate data to examine the variation in the relationships between vegetation activity and climate variables. Results showed that there was an expanding negative response of vegetation growth to climate warming and a positive role of precipitation. The change patterns between NDVI and climate variables over vegetation types during the past three decades pointed an expending negative correlation between NDVI and temperature and a positive role of precipitation over most of the vegetation types (meadow, grassland, shrub, desert, cropland, and forest). Specifically, correlation between NDVI and temperature (PNDVI-T) have shifted from positive to negative in most of the station of temperature-limited areas with evergreen broadleaf forests, whereas precipitation-limited temperate grassland and desert were characterized by a positive PNDVI-P. This study contributes to ongoing investigations of the effects of climate change on vegetation activity. It is also of great importance for designing forest management strategies to cope with climate change.

  6. Modelling shifts in agroclimate and crop cultivar response under climate change

    PubMed Central

    Rötter, Reimund P; Höhn, Jukka; Trnka, Mirek; Fronzek, Stefan; Carter, Timothy R; Kahiluoto, Helena

    2013-01-01

    This paper aims: (i) to identify at national scale areas where crop yield formation is currently most prone to climate-induced stresses, (ii) to evaluate how the severity of these stresses is likely to develop in time and space, and (iii) to appraise and quantify the performance of two strategies for adapting crop cultivation to a wide range of (uncertain) climate change projections. To this end we made use of extensive climate, crop, and soil data, and of two modelling tools: N-AgriCLIM and the WOFOST crop simulation model. N-AgriCLIM was developed for the automatic generation of indicators describing basic agroclimatic conditions and was applied over the whole of Finland. WOFOST was used to simulate detailed crop responses at four representative locations. N-AgriCLIM calculations have been performed nationally for 3829 grid boxes at a 10 × 10 km resolution and for 32 climate scenarios. Ranges of projected shifts in indicator values for heat, drought and other crop-relevant stresses across the scenarios vary widely – so do the spatial patterns of change. Overall, under reference climate the most risk-prone areas for spring cereals are found in south-west Finland, shifting to south-east Finland towards the end of this century. Conditions for grass are likely to improve. WOFOST simulation results suggest that CO2 fertilization and adjusted sowing combined can lead to small yield increases of current barley cultivars under most climate scenarios on favourable soils, but not under extreme climate scenarios and poor soils. This information can be valuable for appraising alternative adaptation strategies. It facilitates the identification of regions in which climatic changes might be rapid or otherwise notable for crop production, requiring a more detailed evaluation of adaptation measures. The results also suggest that utilizing the diversity of cultivar responses seems beneficial given the high uncertainty in climate change projections. PMID:24324870

  7. Functional foods and urban agriculture: two responses to climate change-related food insecurity.

    PubMed

    Dixon, Jane M; Donati, Kelly J; Pike, Lucy L; Hattersley, Libby

    2009-01-01

    Affluent diets have negative effects on the health of the population and the environment. Moreover, the ability of industrialised agricultural ecosystems to continue to supply these diets is threatened by the anticipated consequences of climate change. By challenging the ongoing supply the diets of affluent countries, climate change provides a population and environmental health opportunity. This paper contrasts two strategies for dealing with climate change-related food insecurity. Functional foods are being positioned as one response because they are considered a hyper-efficient mechanism for supplying essential micronutrients. An alternative response is civic and urban agriculture. Rather than emphasising increased economic or nutritional efficiencies, civic agriculture presents a holistic approach to food security that is more directly connected to the economic, environmental and social factors that affect diet and health. PMID:19261211

  8. Testable Predictions for Large-Scale Coastline-Shape Change in Response to Changing Storm Climate

    NASA Astrophysics Data System (ADS)

    Murray, A. B.; Moore, L. J.; McNamara, D.; Brenner, O.; Slott, J.

    2008-12-01

    Recent modeling (Ashton et al. 2001; Ashton and Murray, 2006a) and observations (Ashton and Murray 2006b) suggest that sandy coastlines self-organize into large-scale, plan-view shapes that depend sensitively on the regional wave climate-the distribution of influences on alongshore sediment transport from different deep-water wave-approach angles. Subsequent modeling (Slott et al., 2007) shows that even moderate changes in wave climate, as are likely to arise as storm behaviors shift in the coming century, will cause coastlines to change shape rapidly, compared to a steady-wave-climate scenario. Such large-scale shape changes involve greatly accentuated rates of local erosion, and highly variable erosion/accretion rates. A recent analysis of wave records from the Southeastern US (Komar and Allen, 2007) indicates that wave climates have already been changing over the past three decades; the heights of waves attributable to tropical storms have been increasing, changing the angular distribution of wave influences. Modeling based on these observations leads to predictions of how coastlines in this region should already be changing shape (McNamara et al., in prep.). As a case study, we are examining historical shorelines for the Carolina coastline, to test whether the predicted alongshore patterns of shoreline change can already be detected.

  9. Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution.

    PubMed

    Godoy, Mario D P; de Lacerda, Luiz D

    2015-01-01

    Mangroves function as a natural coastline protection for erosion and inundation, providing important environmental services. Due to their geographical distribution at the continent-ocean interface, the mangrove habitat may suffer heavy impacts from global climate change, maximized by local human activities occurring in a given coastal region. This review analyzed the literature published over the last 25 years, on the documented response of mangroves to environmental change caused by global climate change, taking into consideration 104 case studies and predictive modeling, worldwide. Most studies appeared after the year 2000, as a response to the 1997 IPCC report. Although many reports showed that the world's mangrove area is decreasing due to direct anthropogenic pressure, several others, however, showed that in a variety of habitats mangroves are expanding as a response to global climate change. Worldwide, pole ward migration is extending the latitudinal limits of mangroves due to warmer winters and decreasing the frequency of extreme low temperatures, whereas in low-lying coastal plains, mangroves are migrating landward due to sea level rise, as demonstrated for the NE Brazilian coast. Taking into consideration climate change alone, mangroves in most areas will display a positive response. In some areas however, such as low-lying oceanic islands, such as in the Pacific and the Caribbean, and constrained coastlines, such as the SE Brazilian coast, mangroves will most probably not survive. PMID:25993360

  10. Response to a Regional Climate Change in Antarctic Streams

    NASA Astrophysics Data System (ADS)

    Jaros, C. L.; McKnight, D. M.; Lyons, W.

    2002-05-01

    Sandwiched between the polar ice cap, and the Ross Sea, the McMurdo Dry Valleys represent the largest ice-free region of East Antarctica. During the short austral summer, glacial meltwater streams flow through porous alluvial channels, carrying nutrients to many closed-basin lakes throughout the region. A shallow permafrost depth of up to 0.5 m constrains the melt waters, limiting the interaction with alluvium surfaces to the saturated and wetted compartments of the hyporheic zone. The monitoring of the stream flow and water quality for Taylor and Wright began in 1990 and 1968 respectively, and was incorporated as part of the MCMLTER in 1993. The physical characteristics of these stream channels in large part control the solute chemistry of the waters they contain, with short and steep stream reaches notably depleted in major ions in relation to their more gradual counterparts. Within streams of similar physical characteristics, presence of algal communities further limit the concentrations of nutrients in stream waters entering the lakes. Flowrates in the streams vary greatly from season to season, as well as from day to day, with extreme events impacting both algal populations and channel characteristics. The streamflow in the Dry Valleys has decreased in the past decade in association with colder summer temperatures, a response which differs from reported global trends. When reported, these results caused a stir in the international press.

  11. An energetic perspective on the regional response of precipitation to climate change

    NASA Astrophysics Data System (ADS)

    Muller, C. J.; O'Gorman, P. A.

    2011-08-01

    Understanding and predicting the response of the hydrological cycle to climate change is a major challenge with important societal implications. Much progress has been made in understanding the response of global average precipitation by considering the energy balances of the atmosphere and the surface. This energetic perspective reveals that changes in temperature, greenhouse gases, aerosols, solar forcing and cloud feedbacks can all affect the global average rate of precipitation. Local precipitation changes have conventionally been analysed using the water vapour budget, but here we show that the energetic approach can be extended to local changes in precipitation by including changes in horizontal energy transport. In simulations of twenty-first century climate change, this energy transport accounts for much of the spatial variability in precipitation change. We show that changes in radiative and surface sensible heat fluxes are a guide to the local precipitation response over land and at large scales, but not at small scales over the ocean, where cloud and water vapour radiative feedbacks dampen the response. The energetic approach described here helps bridge the gap between our understanding of global and regional precipitation changes. It could be applied to better understand the response of regional precipitation to different radiative forcings, including geo-engineering schemes, as well as to understand the differences between the fast and slow responses of regional precipitation to such forcings.

  12. Responses of arctic and alpine ecosystems to altered seasonality under climate change

    NASA Astrophysics Data System (ADS)

    Ernakovich, J. G.; Hopping, K. A.; Berdanier, A.; Simpson, R. T.; Kachergis, E. J.; Steltzer, H.; Wallenstein, M. D.

    2012-12-01

    Arctic and alpine ecosystems are largely structured by strong seasonal patterns in abiotic drivers, including solar radiation and air and soil temperature. Because air temperature and precipitation patterns are changing rapidly, the length of the growing season is increasing due to shifts in snowfall, earlier snowmelt in spring, and delayed snowfall in autumn. Although arctic and alpine environments are both characterized by short growing seasons, they differ in fundamental ways that will affect their responses to changing seasonality. We compare meteorological data from sixteen arctic and alpine sites and biological data from two arctic and two alpine sites. We propose that although alpine and arctic ecosystems appear similar under historical climate conditions, especially during the growing season, winter conditions and climate change will result in divergent responses. Biotic responses to changing seasonality will affect belowground and aboveground community composition, trophic dynamics, and the functioning of these ecosystems, including net carbon balance.

  13. Stream nitrate responses to hydrological forcing and climate change in northern forests of the USA (Invited)

    NASA Astrophysics Data System (ADS)

    Sebestyen, S. D.; Campbell, J. L.; Shanley, J. B.; Pourmokhtarian, A.; Driscoll, C. T.; Boyer, E. W.

    2009-12-01

    There is a need to understand how climate variability and change affect nutrient delivery to surface waters. We analyzed long-term records of hydrochemical data to explore how the forms, concentrations, and loadings of nitrogen in forest streams throughout the northern USA vary with catchment wetness. We considered projected changes in growing season length and precipitation patterns to simulate future climate scenarios and to assess how stream nitrate loading responds to hydrological forcing under different climate change scenarios. At the Sleepers River Research Watershed in northeastern Vermont, model results suggest that stream nutrient loadings over the next century will respond to hydrological forcing during climate change that affects the amount of water that flows through the landscape. For example, growing season stream water yield (+20%) and nitrate loadings (+57%) increase in response to greater amounts of precipitation (+28%) during a warmer climate with a longer growing season (+43 days). We further explore these findings by presenting model results from a biogeochemical process model (PnET-BGC) to separate changes that are due to biogeochemical cycling and the effects of hydrological forcing. Our findings suggest that nitrogen cycling and transport will intensify during anthropogenic climate forcing, thereby affecting the timing and magnitude of annual stream nutrient loadings in northern forests of the USA.

  14. Sensitivity and response time of natural systems to climatic change in the late quaternary

    NASA Astrophysics Data System (ADS)

    Wright, H. E.

    Although the leading theory for the cause of climatic change — the Milankovitch perturbations in insolation — indicates variable rates of change at different latitudes, any discussion of the sensitivity and response time of different natural systems is most practical when the climatic change is considered to be relatively abrupt and global rather than gradual and regional. The oxygen-isotope record in glacial ice should have the swiftest response time, but the stratigraphic record in ice sheets at particular localities may be obscured or confused if the glacier flow is irregular. The oxygen-isotope stratigraphy of ocean sediment cores is a sensitive reflection primarily of contemporaneous ice volume, and to a lesser extent ocean temperature. Ocean temperature, however, is recorded more specifically by microfossils in ocean sediments and may reflect global insolation directly, except that in the North Atlantic the influence of glacial meltwater and various feedbacks may override the insolation factor. The differential lags in the response of isotopes and faunas to insolational change are apparent in the ocean sediment stratigraphy. Ice sheets themselves at their terminus may respond to climatic change only slowly if a change in snow accumulation is the factor, because of the time involved in building a thickness sufficient for flow to great distances, but if wastage near the margin is the factor then the response may be more rapid. Some glaciers, however, may advance rapidly without regard to climatic change, as in the case of surging, or they may retreat just as rapidly if they terminate in deep water, through iceberg formation. World sea level is depressed with glacial growth and thus reflects the volume of ice sheets, but isostatic changes in the crust complicate the sea level response not only locally beneath the ice load but elsewhere as well. The pluvial lakes of the American Southwest, correlated in their high levels with intervals of glaciation, show a

  15. Evolutionary response of the egg hatching date of a herbivorous insect under climate change

    NASA Astrophysics Data System (ADS)

    van Asch, Margriet; Salis, Lucia; Holleman, Leonard J. M.; van Lith, Bart; Visser, Marcel E.

    2013-03-01

    Under changing climatic conditions, species need to adapt to their new environment. Genetic adaptation is crucial to prevent population extinction but examples where climate change leads to genetic changes in wild populations have been few. The synchronization between the timing of egg hatching of a herbivorous insect, the winter moth (Operophtera brumata), and the seasonal bud burst of its food plant, oak (Quercus robur), has been disrupted by climate change and a quantitative genetic model predicts that selection will delay the egg hatching date. Here we show, using both long-term observational data and experiments, that the egg hatching date has changed genetically, resulting in closer synchrony with oak bud burst. The observed rate of change matches the predicted rate of change of one day per year. Hence, altered selection pressures, caused by environmental change, result in a rapid adaptive response in insect phenology. These genetic changes in a key life-history trait in this herbivorous insect therefore seem to be fast enough to match the climate-change-induced advancement of their host phenology.

  16. Response of Late Carboniferous and Early Permian Plant Communities to Climate Change

    NASA Astrophysics Data System (ADS)

    Dimichele, William A.; Pfefferkorn, Hermann W.; Gastaldo, Robert A.

    Late Carboniferous and Early Permian strata record the transition from a cold interval in Earth history, characterized by the repeated periods of glaciation and deglaciation of the southern pole, to a warm-climate interval. Consequently, this time period is the best available analogue to the Recent in which to study patterns of vegetational response, both to glacial-interglacial oscillation and to the appearance of warm climate. Carboniferous wetland ecosystems were dominated by spore-producing plants and early gymnospermous seed plants. Global climate changes, largely drying, forced vegetational changes, resulting in a change to a seed plant-dominated world, beginning first at high latitudes during the Carboniferous, reaching the tropics near the Permo-Carboniferous boundary. For most of this time plant assemblages were very conservative in their composition. Change in the dominant vegetation was generally a rapid process, which suggests that environmental thresholds were crossed, and involved little mixing of elements from the wet and dry floras.

  17. Decreasing litter size of marmots over time: a life history response to climate change?

    PubMed

    Tafani, Marion; Cohas, Aurélie; Bonenfant, Christophe; Gaillard, Jean-Michel; Allainé, Dominique

    2013-03-01

    The way that plants and animals respond to climate change varies widely among species, but the biological features underlying their actual response remains largely unknown. Here, from a 20-year monitoring study, we document a continuous decrease in litter size of the Alpine marmot (Marmota marmota) since 1990. To cope with harsh winters, Alpine marmots hibernate in burrows and their reproductive output should depend more on spring conditions compared to animals that are active year-round. However, we show that litter size decreased over time because of the general thinning of winter snow cover that has been repeatedly reported to occur in the Alps over the same period, despite a positive effect of an earlier snowmelt in spring. Our results contrast markedly with a recent study on North American yellow-bellied marmots, suggesting that between-species differences in life histories can lead to opposite responses to climate change, even between closely related species. Our case study therefore demonstrates the idiosyncratic nature of the response to climate change and emphasizes, even for related species with similar ecological niches, that it may be hazardous to extrapolate life history responses to climate change from one species to another. PMID:23687884

  18. Plant response to climate change varies with topography, interactions with neighbors, and ecotype.

    PubMed

    Liancourt, Pierre; Spence, Laura A; Song, Daniel S; Lkhagva, Ariuntsetseg; Sharkhuu, Anarmaa; Boldgiv, Bazartseren; Helliker, Brent R; Petraitis, Peter S; Casper, Brenda B

    2013-02-01

    Predicting the future of any given species represents an unprecedented challenge in light of the many environmental and biological factors that affect organismal performance and that also interact with drivers of global change. In a three-year experiment set in the Mongolian steppe, we examined the response of the common grass Festuca lenensis to manipulated temperature and water while controlling for topographic variation, plant-plant interactions, and ecotypic differentiation. Plant survival and growth responses to a warmer, drier climate varied within the landscape. Response to simulated increased precipitation occurred only in the absence of neighbors, demonstrating that plant-plant interactions can supersede the effects of climate change. F. lenensis also showed evidence of local adaptation in populations that were only 300 m apart. Individuals from the steep and dry upper slope showed a higher stress/drought tolerance, whereas those from the more productive lower slope showed a higher biomass production and a greater ability to cope with competition. Moreover, the response of this species to increased precipitation was ecotype specific, with water addition benefiting only the least stress-tolerant ecotype from the lower slope origin. This multifaceted approach illustrates the importance of placing climate change experiments within a realistic ecological and evolutionary framework. Existing sources of variation impacting plant performance may buffer or obscure climate change effects. PMID:23691663

  19. AO/NAO response to climate change: 2. Relative importance of low- and high-latitude temperature changes

    NASA Astrophysics Data System (ADS)

    Rind, D.; Perlwitz, J.; Lonergan, P.; Lerner, J.

    2005-06-01

    We address the issue of why different models may be getting different responses of the AO/NAO in climate change experiments. The results from part 1 (Rind et al., 2005) suggest that for substantive climate changes, the differences are likely to be found in the patterns of tropospheric climate change, rather than from the stratosphere. We assess the various tropospheric forcings through a variety of experiments. We first use extreme paleoclimate experiments (Ice Age, Paleocene) which feature large variations in the low level latitudinal temperature gradient; the results show that under these circumstances, changes in the eddy transport of sensible heat, and in situ high latitude forcing, dominate the AO response. We next test the effect of more modest SST temperature gradient changes in the current climate, and find a similar result with a model configuration that does not easily transport the low level temperature changes into the upper troposphere. We then reanalyze the results from different 2 × CO2 experiments with the GISS model and find that they can be understood by assessing: (1) the magnitude of tropical SST warming; (2) the translations of that warming into the upper troposphere; (3) the change in the extratropical low altitude temperature gradient; and (4) the change in the high latitude SST/sea ice response. We suggest that these features might explain the varying results among modeling groups, and that forecasts will not converge until these features do.

  20. Deep-Sea Biodiversity Response to Abrupt Deglacial and Holocene Climate Changes

    NASA Astrophysics Data System (ADS)

    Yasuhara, M.

    2014-12-01

    High-resolution records of microfossil assemblages from deep-sea sediment cores covering the last 20,000 years in the North Atlantic Ocean were investigated to understand biotic responses to abrupt climate changes over decadal-centennial timescales. The results show pervasive control of deep-sea benthic species diversity by rapidly changing climate. Species diversity rapidly increased during abrupt stadial events during the last deglacial and the Holocene interglacial periods. These included the well-known Heinrich 1, the Younger Dryas, and the 8.2 ka events when the strength of Atlantic Meridional Overturning Circulation (AMOC) decreased. In addition, there is evidence for quasi-cyclic changes in biodiversity at a ~1500-year periodicity. Statistical analyses revealed that AMOC-driven bottom-water-temperature variability is a primary influence on deep-sea biodiversity. Our results may portend pervasive, synchronous and sudden ecosystem responses to human-induced changes to climate and ocean circulation in this century. Exceptionally highly resolved fossil records help us to understand past, present and future ecosystem responses to climate changes by bridging the gap between biological and palaeontological time-scales.

  1. Modelling climate change responses in tropical forests: similar productivity estimates across five models, but different mechanisms and responses

    NASA Astrophysics Data System (ADS)

    Rowland, L.; Harper, A.; Christoffersen, B. O.; Galbraith, D. R.; Imbuzeiro, H. M. A.; Powell, T. L.; Doughty, C.; Levine, N. M.; Malhi, Y.; Saleska, S. R.; Moorcroft, P. R.; Meir, P.; Williams, M.

    2014-11-01

    Accurately predicting the response of Amazonia to climate change is important for predicting changes across the globe. However, changes in multiple climatic factors simultaneously may result in complex non-linear responses, which are difficult to predict using vegetation models. Using leaf and canopy scale observations, this study evaluated the capability of five vegetation models (CLM3.5, ED2, JULES, SiB3, and SPA) to simulate the responses of canopy and leaf scale productivity to changes in temperature and drought in an Amazonian forest. The models did not agree as to whether gross primary productivity (GPP) was more sensitive to changes in temperature or precipitation. There was greater model-data consistency in the response of net ecosystem exchange to changes in temperature, than in the response to temperature of leaf area index (LAI), net photosynthesis (An) and stomatal conductance (gs). Modelled canopy scale fluxes are calculated by scaling leaf scale fluxes to LAI, and therefore in this study similarities in modelled ecosystem scale responses to drought and temperature were the result of inconsistent leaf scale and LAI responses among models. Across the models, the response of An to temperature was more closely linked to stomatal behaviour than biochemical processes. Consequently all the models predicted that GPP would be higher if tropical forests were 5 °C colder, closer to the model optima for gs. There was however no model consistency in the response of the An-gs relationship when temperature changes and drought were introduced simultaneously. The inconsistencies in the An-gs relationships amongst models were caused by to non-linear model responses induced by simultaneous drought and temperature change. To improve the reliability of simulations of the response of Amazonian rainforest to climate change the mechanistic underpinnings of vegetation models need more complete validation to improve accuracy and consistency in the scaling of processes from

  2. Climate Sensitivity Runs and Regional Hydrologic Modeling for Predicting the Response of the Greater Florida Everglades Ecosystem to Climate Change

    NASA Astrophysics Data System (ADS)

    Obeysekera, Jayantha; Barnes, Jenifer; Nungesser, Martha

    2015-04-01

    It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature, ±10 % change in precipitation, and a 0.46 m (1.5 feet) increase in sea level for the 50-year planning horizon. The results suggested that, depending on the rainfall and temperature scenario, there would be significant changes in water budgets, ecosystem performance, and in water supply demands met. The increased sea level scenarios also show that the ground water levels would increase significantly with associated implications for flood protection in the urbanized areas of southeastern Florida.

  3. Climate sensitivity runs and regional hydrologic modeling for predicting the response of the greater Florida Everglades ecosystem to climate change.

    PubMed

    Obeysekera, Jayantha; Barnes, Jenifer; Nungesser, Martha

    2015-04-01

    It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature, ±10 % change in precipitation, and a 0.46 m (1.5 feet) increase in sea level for the 50-year planning horizon. The results suggested that, depending on the rainfall and temperature scenario, there would be significant changes in water budgets, ecosystem performance, and in water supply demands met. The increased sea level scenarios also show that the ground water levels would increase significantly with associated implications for flood protection in the urbanized areas of southeastern Florida. PMID:25011530

  4. Elevation-dependent responses of tree mast seeding to climate change over 45 years

    PubMed Central

    Allen, Robert B; Hurst, Jennifer M; Portier, Jeanne; Richardson, Sarah J

    2014-01-01

    We use seed count data from a New Zealand mono-specific mountain beech forest to test for decadal trends in seed production along an elevation gradient in relation to changes in climate. Seedfall was collected (1965 to 2009) from seed trays located on transect lines at fixed elevations along an elevation gradient (1020 to 1370 m). We counted the number of seeds in the catch of each tray, for each year, and determined the number of viable seeds. Climate variables were obtained from a nearby (<2 km) climate station (914-m elevation). Variables were the sum or mean of daily measurements, using periods within each year known to correlate with subsequent interannual variation in seed production. To determine trends in mean seed production, at each elevation, and climate variables, we used generalized least squares (GLS) regression. We demonstrate a trend of increasing total and viable seed production, particularly at higher elevations, which emerged from marked interannual variation. Significant changes in four seasonal climate variables had GLS regression coefficients consistent with predictions of increased seed production. These variables subsumed the effect of year in GLS regressions with a greater influence on seed production with increasing elevation. Regression models enforce a view that the sequence of climate variables was additive in their influence on seed production throughout a reproductive cycle spanning more than 2 years and including three summers. Models with the most support always included summer precipitation as the earliest variable in the sequence followed by summer maximum daily temperatures. We interpret this as reflecting precipitation driven increases in soil nutrient availability enhancing seed production at higher elevations rather than the direct effects of climate, stand development or rising atmospheric CO2 partial pressures. Greater sensitivity of tree seeding at higher elevations to changes in climate reveals how ecosystem responses to

  5. Climate change as a three-part ethical problem: a response to Jamieson and Gardiner.

    PubMed

    Kingston, Ewan

    2014-12-01

    Dale Jamieson has claimed that conventional human-directed ethical concepts are an inadequate means for accurately understanding our duty to respond to climate change. Furthermore, he suggests that a responsibility to respect nature can instead provide the appropriate framework with which to understand such a duty. Stephen Gardiner has responded by claiming that climate change is a clear case of ethical responsibility, but the failure of institutions to respond to it creates a (not unprecedented) political problem. In assessing the debate between Gardiner and Jamieson, I develop an analysis which shows a three-part structure to the problem of climate change, in which the problem Gardiner identifies is only one of three sub-problems of climate change. This analysis highlights difficulties with Jamieson's argument that the duty of respect for nature is necessary for a full understanding of climate ethics, and suggests how a human-directed approach based on the three-part analysis can avoid Jamieson's charge of inadequacy. PMID:24146296

  6. Climatic effects of 1950-2050 changes in US anthropogenic aerosols - Part 2: Climate response

    NASA Astrophysics Data System (ADS)

    Leibensperger, E. M.; Mickley, L. J.; Jacob, D. J.; Chen, W.-T.; Seinfeld, J. H.; Nenes, A.; Adams, P. J.; Streets, D. G.; Kumar, N.; Rind, D.

    2011-08-01

    We investigate the climate response to US anthropogenic aerosol sources over the 1950 to 2050 period by using the NASA GISS general circulation model (GCM) and comparing to observed US temperature trends. Time-dependent aerosol distributions are generated from the GEOS-Chem chemical transport model applied to historical emission inventories and future projections. Radiative forcing from US anthropogenic aerosols peaked in 1970-1990 and has strongly declined since due to air quality regulations. We find that the regional radiative forcing from US anthropogenic aerosols elicits a strong regional climate response, cooling the central and eastern US by 0.5-1.0 °C on average during 1970-1990, with the strongest effects on maximum daytime temperatures in summer and autumn. Aerosol cooling reflects comparable contributions from direct and indirect (cloud-mediated) radiative effects. Absorbing aerosol (mainly black carbon) has negligible warming effect. Aerosol cooling reduces surface evaporation and thus decreases precipitation along the US east coast, but also increases the southerly flow of moisture from the Gulf of Mexico resulting in increased cloud cover and precipitation in the central US. Observations over the eastern US show a lack of warming in 1960-1980 followed by very rapid warming since, which we reproduce in the GCM and attribute to trends in US anthropogenic aerosol sources. Present US aerosol concentrations are sufficiently low that future air quality improvements are projected to cause little further warming in the US (0.1 °C over 2010-2050). We find that most of the potential warming from aerosol source controls in the US has already been realized over the 1980-2010 period.

  7. Uncertainty of the hydrological response to climate change conditions; 605 basins, 3 hydrological models, 5 climate models, 5 hydrological variables

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke; Mizukami, Naoki; Newman, Andrew; Clark, Martyn; Teuling, Adriaan

    2016-04-01

    Many studies investigated the effect of a changing climate on the hydrological response of a catchment and uncertainty of the effect coming from hydrologic modelling (e.g., forcing, hydrologic model structures, and parameters). However, most past studies used only a single or a small number of catchments. To go beyond the case-study, and to assess the uncertainty involved in modelling the hydrological impact of climate change more comprehensively, we studied 605 basins over a wide range of climate regimes throughout the contiguous USA. We used three different widely-used hydrological models (VIC, HBV, SAC), which we forced with five distinct climate model outputs. The hydrological models have been run for a base period (1986-2008) for which observations were available, and for a future period (2070-2099). Instead of calibrating each hydrological model for each basin, the model has been run with a parameter sample (varying from 1600 to 1900 samples dependent on the number of free parameters in the model). Five hydrological states and fluxes were stored; discharge, evapotranspiration, soil moisture, SWE and snow melt, and 15 different metrics and signatures have been obtained for each model run. With the results, we conduct a sensitivity analysis over the change in signatures from the future period compared to the base period. In this way, we can identify the parameters that are responsible for certain projected changes, and identify the processes responsible for this change. By using three different models, in which VIC is most distinctive in including explicit vegetation parameters, we can compare different process representations and the effect on the projected hydrological change.

  8. The dependence of wintertime Mediterranean precipitation on the atmospheric circulation response to climate change

    NASA Astrophysics Data System (ADS)

    Zappa, Giuseppe; Hoskins, Brian; Shepherd, Ted

    2016-04-01

    Climate models indicate a future wintertime precipitation reduction in the Mediterranean region which may have large socio-economic impacts. However, there is large uncertainty in the amplitude of the projected precipitation reduction and this limits the possibility to inform effective adaptation planning. We analyse CMIP5 climate model output to quantify the role of atmospheric circulation in the precipitation change and the time of emergence of the Mediterranean precipitation response. It is found that a simple circulation index, i.e. the 850 hPa zonal wind (U850) in North Africa, well describes the year to year fluctuations in the area-averaged Mediterranean precipitation, with positive (i.e. westerly) U850 anomalies in North Africa being associated with positive precipitation anomalies. Under climate change, U850 in North Africa and the Mediterranean precipitation are both projected to decrease consistently with the relationship found in the inter-annual variability. This enables us to estimate that about 85% of the CMIP5 mean precipitation response and 80% of the variance in the inter-model spread are related to changes in the atmospheric circulation. In contrast, there is no significant correlation between the mean precipitation response and the global-mean surface warming across the models. We also find that the precipitation response to climate change might already emerge from internal variability by 2025 relative to 1960-1990 according to the climate models with a large circulation response. This implies that it might soon be possible to test model projections using observations. Finally, some of the mechanisms which are important for the Mediterranean circulation response in the CMIP5 models are discussed.

  9. Unexpected patterns of vegetation distribution response and climate change velocities in cold ecosystems

    NASA Astrophysics Data System (ADS)

    Macias-Fauria, M.; Johnson, E. A.; Forbes, B. C.; Willis, K. J.

    2013-12-01

    In cold ecosystems such as sub-alpine forests and forest-tundra, vegetation geographical ranges are expected to expand upward/northward in a warmer world. Such moving fronts have been predicted to 1) decrease the remaining alpine area in mountain systems, increasing fragmentation and extinction risk of many alpine taxa, and 2) fundamentally modify the energy budget of newly afforested areas, enhancing further regional warming due to a reduction in albedo. The latter is particularly significant in the forest-tundra, where changes over large regions can have regional-to-global effects on climate. An integral part of the expected range shifts is their velocity. Whereas range shifts across thermal gradients can theoretically be fast in an elevation gradient relative to climate velocity (i.e. rate of climate change) due to the short distances involved, large lags are expected over the flat forest-tundra. Mountain regions have thus been identified as buffer areas where species can track climate change, in opposition to flat terrain where climate velocity is faster. Thus, much shorter time-to-equilibrium are expected for advancing upslope sub-alpine forest than for advancing northern boreal forest. We contribute to this discussion by showing two mechanisms that might largely alter the above predictions in opposite directions: 1) In mountain regions, terrain heterogeneity not only allows for slower climate velocities, but slope processes largely affect the advance of vegetation. Indeed, such mechanisms can potentially reduce the climatic signal in vegetation distribution limits (e.g. treeline), precluding it from migrating to climatically favourable areas - since these areas occur in geologically unfavourable ones. Such seemingly local control to species range shifts was found to reduce the climate-sensitive treeline areas in the sub-alpine forest of the Canadian Rocky Mountains to ~5% at a landscape scale, fundamentally altering the predictions of vegetation response to

  10. Quantifying the hydrological responses to climate change in an intact forested small watershed in Southern China

    USGS Publications Warehouse

    Zhou, G.; Wei, X.; Wu, Y.; Huang, Y.; Yan, J.; Zhang, Dongxiao; Zhang, Q.; Liu, J.; Meng, Z.; Wang, C.; Chu, G.; Liu, S.; Tang, X.; Liu, Xiuying

    2011-01-01

    Responses of hydrological processes to climate change are key components in the Intergovernmental Panel for Climate Change (IPCC) assessment. Understanding these responses is critical for developing appropriate mitigation and adaptation strategies for sustainable water resources management and protection of public safety. However, these responses are not well understood and little long-term evidence exists. Herein, we show how climate change, specifically increased air temperature and storm intensity, can affect soil moisture dynamics and hydrological variables based on both long-term observation and model simulations using the Soil and Water Assessment Tool (SWAT) in an intact forested watershed (the Dinghushan Biosphere Reserve) in Southern China. Our results show that, although total annual precipitation changed little from 1950 to 2009, soil moisture decreased significantly. A significant decline was also found in the monthly 7-day low flow from 2000 to 2009. However, the maximum daily streamflow in the wet season and unconfined groundwater tables have significantly increased during the same 10-year period. The significant decreasing trends on soil moisture and low flow variables suggest that the study watershed is moving towards drought-like condition. Our analysis indicates that the intensification of rainfall storms and the increasing number of annual no-rain days were responsible for the increasing chance of both droughts and floods. We conclude that climate change has indeed induced more extreme hydrological events (e.g. droughts and floods) in this watershed and perhaps other areas of Southern China. This study also demonstrated usefulness of our research methodology and its possible applications on quantifying the impacts of climate change on hydrology in any other watersheds where long-term data are available and human disturbance is negligible. ?? 2011 Blackwell Publishing Ltd.

  11. Quantifying the hydrological responses to climate change in an intact forested small watershed in southern China

    USGS Publications Warehouse

    Zhou, Guo-Yi; Wei, Xiaohua; Wu, Yiping; Liu, Shu-Guang; Huang, Yuhui; Yan, Junhua; Zhang, Deqiang; Zhang, Qianmei; Liu, Juxiu; Meng, Ze; Wang, Chunlin; Chu, Guowei; Liu, Shizhong; Tang, Xu-Li; Liu, Xiaodong

    2011-01-01

    Responses of hydrological processes to climate change are key components in the Intergovernmental Panel for Climate Change (IPCC) assessment. Understanding these responses is critical for developing appropriate mitigation and adaptation strategies for sustainable water resources management and protection of public safety. However, these responses are not well understood and little long-term evidence exists. Herein, we show how climate change, specifically increased air temperature and storm intensity, can affect soil moisture dynamics and hydrological variables based on both long-term observation and model simulations using the Soil and Water Assessment Tool (SWAT) in an intact forested watershed (the Dinghushan Biosphere Reserve) in Southern China. Our results show that, although total annual precipitation changed little from 1950 to 2009, soil moisture decreased significantly. A significant decline was also found in the monthly 7-day low flow from 2000 to 2009. However, the maximum daily streamflow in the wet season and unconfined groundwater tables have significantly increased during the same 10-year period. The significant decreasing trends on soil moisture and low flow variables suggest that the study watershed is moving towards drought-like condition. Our analysis indicates that the intensification of rainfall storms and the increasing number of annual no-rain days were responsible for the increasing chance of both droughts and floods. We conclude that climate change has indeed induced more extreme hydrological events (e.g. droughts and floods) in this watershed and perhaps other areas of Southern China. This study also demonstrated usefulness of our research methodology and its possible applications on quantifying the impacts of climate change on hydrology in any other watersheds where long-term data are available and human disturbance is negligible.

  12. Limited hydrologic response to Pleistocene climate change in deep vadose zones — Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

    Paces, James B.; Neymark, Leonid A.; Whelan, Joseph F.; Wooden, Joseph L.; Lund, Steven P.; Marshall, Brian D.

    2010-12-01

    Understanding the movement of water through thick vadose zones, especially on time scales encompassing long-term climate change, is increasingly important as societies utilize semi-arid environments for both water resources and sites viewed as favorable for long-term disposal or storage of hazardous waste. Hydrologic responses to Pleistocene climate change within a deep vadose zone in the eastern Mojave Desert at Yucca Mountain, Nevada, were evaluated by uranium-series dating of finely layered hyalitic opal using secondary ion mass spectrometry. Opal is present within cm-thick secondary hydrogenic mineral crusts coating floors of lithophysal cavities in fractured volcanic rocks at depths of 200 to 300 m below land surface. Uranium concentrations in opal fluctuate systematically between 5 and 550 μg/g. Age-calibrated profiles of uranium concentration correlate with regional climate records over the last 300,000 years and produce time-series spectral peaks that have distinct periodicities of 100- and 41-ka, consistent with planetary orbital parameters. These results indicate that the chemical compositions of percolating solutions varied in response to near-surface, climate-driven processes. However, slow (micrometers per thousand years), relatively uniform growth rates of secondary opal and calcite deposition spanning several glacial-interglacial climate cycles imply that water fluxes in the deep vadose zone remained low and generally buffered from the large fluctuations in available surface moisture during different climates.

  13. Limited hydrologic response to Pleistocene climate change in deep vadose zones - Yucca Mountain, Nevada

    USGS Publications Warehouse

    Paces, J.B.; Neymark, L.A.; Whelan, J.F.; Wooden, J.L.; Lund, S.P.; Marshall, B.D.

    2010-01-01

    Understanding the movement of water through thick vadose zones, especially on time scales encompassing long-term climate change, is increasingly important as societies utilize semi-arid environments for both water resources and sites viewed as favorable for long-term disposal or storage of hazardous waste. Hydrologic responses to Pleistocene climate change within a deep vadose zone in the eastern Mojave Desert at Yucca Mountain, Nevada, were evaluated by uranium-series dating of finely layered hyalitic opal using secondary ion mass spectrometry. Opal is present within cm-thick secondary hydrogenic mineral crusts coating floors of lithophysal cavities in fractured volcanic rocks at depths of 200 to 300 m below land surface. Uranium concentrations in opal fluctuate systematically between 5 and 550 μg/g. Age-calibrated profiles of uranium concentration correlate with regional climate records over the last 300,000 years and produce time-series spectral peaks that have distinct periodicities of 100- and 41-ka, consistent with planetary orbital parameters. These results indicate that the chemical compositions of percolating solutions varied in response to near-surface, climate-driven processes. However, slow (micrometers per thousand years), relatively uniform growth rates of secondary opal and calcite deposition spanning several glacial–interglacial climate cycles imply that water fluxes in the deep vadose zone remained low and generally buffered from the large fluctuations in available surface moisture during different climates.

  14. Catchment Sensitivity to Changing Climate Conditions: Does the Landscape Control Hydrological Responses?

    NASA Astrophysics Data System (ADS)

    Quesada Montano, B.; Teutschbein, C.; Grabs, T.; Karlsen, R.; Laudon, H.; Bishop, K. H.

    2015-12-01

    It has long been recognized that streamflow-generating processes are not only dependent on climatic conditions, but also affected by physical catchment properties such as topography, geology, soils and land cover. We hypothesize that these landscape characteristics do not only lead to highly variable hydrologic behavior of rather similar catchments under the same stationary climate conditions, but that they also play a fundamental role for the sensitivity of a catchment to a changing climate. A multi-model ensemble based on 15 regional climate models was combined with a multi-catchment approach to explore the hydrologic sensitivity of 14 partially nested and rather similar catchments in Northern Sweden to changing climate conditions and the importance of small-scale spatial variability. Current (1981-2010) and future (2061-2090) streamflow was simulated with the HBV model. As expected, projected increases in temperature and precipitation resulted in increased total available streamflow, with lower spring and summer flows, but substantially higher winter streamflow. Furthermore, significant changes in flow durations with lower chances of both high and low flows can be expected in boreal Sweden in the future. This overall trend in projected streamflow pattern changes was comparable among the analyzed catchments while the magnitude of change differed considerably. This suggests that catchments belonging to the same region can show distinctly different degrees of hydrological responses to the same external climate change signal. We reason that differences in spatially distributed physical catchment properties at smaller scales are not only of great importance for current streamflow behavior, but also play a major role as first-order control for the sensitivity of catchments to changing climate conditions.

  15. Potential Changes in Disease Patterns and Pharmaceutical Use in Response to Climate Change

    PubMed Central

    Redshaw, Clare H.; Stahl-Timmins, Will M.; Fleming, Lora E.; Davidson, Iain; Depledge, Michael H.

    2013-01-01

    As climate change alters environmental conditions, the incidence and global patterns of human diseases are changing. These modifications to disease profiles and the effects upon human pharmaceutical usage are discussed. Climate-related environmental changes are associated with a rise in the incidence of chronic diseases already prevalent in the Northern Hemisphere, for example, cardiovascular disease and mental illness, leading to greater use of associated heavily used Western medications. Sufferers of respiratory diseases may exhibit exacerbated symptoms due to altered environmental conditions (e.g., pollen). Respiratory, water-borne, and food-borne toxicants and infections, including those that are vector borne, may become more common in Western countries, central and eastern Asia, and across North America. As new disease threats emerge, substantially higher pharmaceutical use appears inevitable, especially of pharmaceuticals not commonly employed at present (e.g., antiprotozoals). The use of medications for the treatment of general symptoms (e.g., analgesics) will also rise. These developments need to be viewed in the context of other major environmental changes (e.g., industrial chemical pollution, biodiversity loss, reduced water and food security) as well as marked shifts in human demographics, including aging of the population. To identify, prevent, mitigate, and adapt to potential threats, one needs to be aware of the major factors underlying changes in the use of pharmaceuticals and their subsequent release, deliberately or unintentionally, into the environment. This review explores the likely consequences of climate change upon the use of medical pharmaceuticals in the Northern Hemisphere. PMID:23909463

  16. Consistent response of vegetation dynamics to recent climate change in tropical mountain regions.

    PubMed

    Krishnaswamy, Jagdish; John, Robert; Joseph, Shijo

    2014-01-01

    Global climate change has emerged as a major driver of ecosystem change. Here, we present evidence for globally consistent responses in vegetation dynamics to recent climate change in the world's mountain ecosystems located in the pan-tropical belt (30°N-30°S). We analyzed decadal-scale trends and seasonal cycles of vegetation greenness using monthly time series of satellite greenness (Normalized Difference Vegetation Index) and climate data for the period 1982-2006 for 47 mountain protected areas in five biodiversity hotspots. The time series of annual maximum NDVI for each of five continental regions shows mild greening trends followed by reversal to stronger browning trends around the mid-1990s. During the same period we found increasing trends in temperature but only marginal change in precipitation. The amplitude of the annual greenness cycle increased with time, and was strongly associated with the observed increase in temperature amplitude. We applied dynamic models with time-dependent regression parameters to study the time evolution of NDVI-climate relationships. We found that the relationship between vegetation greenness and temperature weakened over time or was negative. Such loss of positive temperature sensitivity has been documented in other regions as a response to temperature-induced moisture stress. We also used dynamic models to extract the trends in vegetation greenness that remain after accounting for the effects of temperature and precipitation. We found residual browning and greening trends in all regions, which indicate that factors other than temperature and precipitation also influence vegetation dynamics. Browning rates became progressively weaker with increase in elevation as indicated by quantile regression models. Tropical mountain vegetation is considered sensitive to climatic changes, so these consistent vegetation responses across widespread regions indicate persistent global-scale effects of climate warming and associated moisture

  17. Soil respiration response to climate change in Pacific Northwest prairies is mediated by a regional Mediterranean climate gradient.

    PubMed

    Reynolds, Lorien L; Johnson, Bart R; Pfeifer-Meister, Laurel; Bridgham, Scott D

    2015-01-01

    Soil respiration is expected to increase with rising global temperatures but the degree of response may depend on soil moisture and other local factors. Experimental climate change studies from single sites cannot discern whether an observed response is site-dependent or generalizable. To deconvolve site-specific vs. regional climatic controls, we examined soil respiration for 18 months along a 520 km climate gradient in three Pacific Northwest, USA prairies that represents increasingly severe Mediterranean conditions from north to south. At each site we implemented a fully factorial combination of 2.5-3 °C warming and 20% added precipitation intensity. The response of soil respiration to warming was driven primarily by the latitudinal climate gradient and not site-specific factors. Warming increased respiration at all sites during months when soil moisture was not limiting. However, these gains were offset by reductions in respiration during seasonal transitions and summer drought due to lengthened periods of soil moisture limitation. The degree of this offset varied along the north-south climate gradient such that in 2011 warming increased cumulative annual soil respiration 28.6% in the northern site, 13.5% in the central site, and not at all in the southern site. Precipitation also stimulated soil respiration more frequently in the south, consistent with an increased duration of moisture limitation. The best predictors of soil respiration in nonlinear models were the Normalized Difference Vegetation Index (NDVI), antecedent soil moisture, and temperature but these models provided biased results at high and low soil respiration. NDVI was an effective integrator of climate and site differences in plant productivity in terms of their combined effects on soil respiration. Our results suggest that soil moisture limitation can offset the effect of warming on soil respiration, and that greater growing-season moisture limitation would constrain cumulative annual

  18. What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change.

    PubMed

    Vetter, Sebastian G; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

    2015-01-01

    Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species' demographic response to climate change. PMID:26158846

  19. Regional and seasonal response of a West Nile virus vector to climate change

    PubMed Central

    Morin, Cory W.; Comrie, Andrew C.

    2013-01-01

    Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions. PMID:24019459

  20. Regional and seasonal response of a West Nile virus vector to climate change.

    PubMed

    Morin, Cory W; Comrie, Andrew C

    2013-09-24

    Climate change will affect the abundance and seasonality of West Nile virus (WNV) vectors, altering the risk of virus transmission to humans. Using downscaled general circulation model output, we calculate a WNV vector's response to climate change across the southern United States using process-based modeling. In the eastern United States, Culex quinquefasciatus response to projected climate change displays a latitudinal and elevational gradient. Projected summer population depressions as a result of increased immature mortality and habitat drying are most severe in the south and almost absent further north; extended spring and fall survival is ubiquitous. Much of California also exhibits a bimodal pattern. Projected onset of mosquito season is delayed in the southwestern United States because of extremely dry and hot spring and summers; however, increased temperature and late summer and fall rains extend the mosquito season. These results are unique in being a broad-scale calculation of the projected impacts of climate change on a WNV vector. The results show that, despite projected widespread future warming, the future seasonal response of C. quinquefasciatus populations across the southern United States will not be homogeneous, and will depend on specific combinations of local and regional conditions. PMID:24019459

  1. What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change

    PubMed Central

    Vetter, Sebastian G.; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

    2015-01-01

    Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species’ demographic response to climate change. PMID:26158846

  2. Global climatic change

    SciTech Connect

    Houghton, R.A.; Woodwell, G.M.

    1989-04-01

    This paper reviews the climatic effects of trace gases such as carbon dioxide and methane. It discusses the expected changes from the increases in trace gases and the extent to which the expected changes can be found in the climate record and in the retreat of glaciers. The use of ice cores in correlating atmospheric composition and climate is discussed. The response of terrestrial ecosystems as a biotic feedback is discussed. Possible responses are discussed, including reduction in fossil-fuel use, controls on deforestation, and reforestation. International aspects, such as the implications for developing nations, are addressed.

  3. Changing crops in response to climate: virtual Nang Rong, Thailand in an agent based simulation

    PubMed Central

    Malanson, George P.; Verdery, Ashton M.; Walsh, Stephen J.; Sawangdee, Yothin; Heumann, Benjamin W.; McDaniel, Philip M.; Frizzelle, Brian G.; Williams, Nathalie E.; Yao, Xiaozheng; Entwisle, Barbara; Rindfuss, Ronald R.

    2014-01-01

    The effects of extended climatic variability on agricultural land use were explored for the type of system found in villages of northeastern Thailand. An agent based model developed for the Nang Rong district was used to simulate land allotted to jasmine rice, heavy rice, cassava, and sugar cane. The land use choices in the model depended on likely economic outcomes, but included elements of bounded rationality in dependence on household demography. The socioeconomic dynamics are endogenous in the system, and climate changes were added as exogenous drivers. Villages changed their agricultural effort in many different ways. Most villages reduced the amount of land under cultivation, primarily with reduction in jasmine rice, but others did not. The variation in responses to climate change indicates potential sensitivity to initial conditions and path dependence for this type of system. The differences between our virtual villages and the real villages of the region indicate effects of bounded rationality and limits on model applications. PMID:25061240

  4. Change in atmospheric mineral aerosols in response to climate: Last glacial period, preindustrial, modern, and doubled carbon dioxide climates

    USGS Publications Warehouse

    Mahowald, N.M.; Muhs, D.R.; Levis, S.; Rasch, P.J.; Yoshioka, M.; Zender, C.S.; Luo, C.

    2006-01-01

    Desert dust simulations generated by the National Center for Atmospheric Research's Community Climate System Model for the current climate are shown to be consistent with present day satellite and deposition data. The response of the dust cycle to last glacial maximum, preindustrial, modern, and doubled-carbon dioxide climates is analyzed. Only natural (non-land use related) dust sources are included in this simulation. Similar to some previous studies, dust production mainly responds to changes in the source areas from vegetation changes, not from winds or soil moisture changes alone. This model simulates a +92%, +33%, and -60% change in dust loading for the last glacial maximum, preindustrial, and doubled-carbon dioxide climate, respectively, when impacts of carbon dioxide fertilization on vegetation are included in the model. Terrestrial sediment records from the last glacial maximum compiled here indicate a large underestimate of deposition in continental regions, probably due to the lack of simulation of glaciogenic dust sources. In order to include the glaciogenic dust sources as a first approximation, we designate the location of these sources, and infer the size of the sources using an inversion method that best matches the available data. The inclusion of these inferred glaciogenic dust sources increases our dust flux in the last glacial maximum from 2.1 to 3.3 times current deposition. Copyright 2006 by the American Geophysical Union.

  5. Compensation and climate: Latitudinal variation in ecototherm response to environmental change

    SciTech Connect

    Curtin, C.G.

    1995-06-01

    Thermal preference measured in a laboratory thermal gradient, and field body temperatures in a field enclosure, contrast the fundamental and realized thermal niches of ornate box turtles (Terrapene ornata) from northern, central, and southern locations. The relatively warmer thermal preference of southern turtles appears to result in lower body temperatures and relatively shorter activity periods. Variation in thermal constraints are input into computer simulations of ectotherm response to climate to assess latitudinal variation in turtle response to microclimate cooling (4{degrees} C), current climate (1970-1990), and climatic warming (3-5{degrees} C). Climatic warming is calculated to lead to a northward shift in turtle range and distribution with increases in northern and declines in southern populations. Microclimate cooling is estimated to result in declines in northern areas and in the core of the box turtle range. The local changes in microclimate, such as can result from shifts in land-use, can be greater than those resulting from large scale changes in climate. Suggesting that land managers and conservation biologists need to focus greater attention on the impact of changes in within patch structure of plant associations and its implications for alteration of microclimate and species life history.

  6. Soil erosion under climate change: simulatingthe response of temperature and rainfall changes in three UK catchments

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Walker-Springett, Kate J.; Constantine, José Antonio; Hales, Tristram C.

    2015-04-01

    Soil erosion by water cost in environmental damages across the Great Britain is estimated in over £200m (2014 GBP) each year and could increase for the effect of climate change. Assessing the potential for increased climate-driven soil erosion, due to the several water processes involved (e.g., infiltration excess, return flow, direct precipitation onto saturated soil),is recognizedas a complex task. Climate change can have a positive and direct effect on soil erosionsuch the case of increasing rainfall in amount and intensity, or an indirect effect through the variation of the atmospheric CO2 level, which can improve plant productivityandwater infiltration capacity of soil reducing the likelihood of soil erosion. Changes in vegetation patterns and typologies with a different protection effect can lead also the soil system to dramatic changes in soil erosion rates, potentially amplifying or ameliorating the direct effects of climate change.Climate, vegetation and soil erosion are thus connected and several feedback effects could be accounted in the study of global change. Understanding these interactions may be a primary goal for clarifying the impact of global change on soil erosion and its consequences on related soil functions such as water and organic carbon storage support to vegetation and agricultural production. In this research, focused on three UK catchments (i.e. Conwy, 627 km2, Wales; Ehen, 225 km2, England; and Dee, 2100 km2, Scotland), we simulated soil erosionapplying SRES climatic scenarios(IPCC, 2000) for different CO2 emission levels. We modelled using Pesera "The Pan European Soil Erosion Risk Assessment" (Kirkby et al., 2004), a model for vegetation growing and soil erosion evaluation at regional scale. For each catchment,we realised a sensitivity - analysis - like test investigating different increments in temperature and rainfall, then, we compared the results of the SRES scenarios with the issues of the parametric sensitivity analysis. The

  7. Assessing Forest Carbon Response to Climate Change and Disturbances Using Long-term Hydro-climatic Observations and Simulations

    NASA Astrophysics Data System (ADS)

    Trettin, C.; Dai, Z.; Amatya, D. M.

    2014-12-01

    Long-term climatic and hydrologic observations on the Santee Experimental Forest in the lower coastal plain of South Carolina were used to estimate long-term changes in hydrology and forest carbon dynamics for a pair of first-order watersheds. Over 70 years of climate data indicated that warming in this forest area in the last decades was faster than the global mean; 35+ years of hydrologic records showed that forest ecosystem succession three years following Hurricane Hugo caused a substantial change in the ratio of runoff to precipitation. The change in this relationship between the paired watersheds was attributed to altered evapotranspiration processes caused by greater abundance of pine in the treatment watershed and regeneration of the mixed hardwood-pine forest on the reference watershed. The long-term records and anomalous observations are highly valuable for reliable calibration and validation of hydrological and biogeochemical models capturing the effects of climate variability. We applied the hydrological model MIKESHE that showed that runoff and water table level are sensitive to global warming, and that the sustained warming trends can be expected to decrease stream discharge and lower the mean water table depth. The spatially-explicit biogeochemical model Forest-DNDC, validated using biomass measurements from the watersheds, was used to assess carbon dynamics in response to high resolution hydrologic observation data and simulation results. The simulations showed that the long-term spatiotemporal carbon dynamics, including biomass and fluxes of soil carbon dioxide and methane were highly regulated by disturbance regimes, climatic conditions and water table depth. The utility of linked-modeling framework demonstrated here to assess biogeochemical responses at the watershed scale suggests applications for assessing the consequences of climate change within an urbanizing forested landscape. The approach may also be applicable for validating large

  8. Nile Basin Vegetation Response and Vulnerability to Climate Change: A Multi-Sensor Remote Sensing Approach

    NASA Astrophysics Data System (ADS)

    Yitayew, M.; Didan, K.; Barreto-munoz, A.

    2013-12-01

    changes in the vegetation index signal and to a lesser degree the change in land cover and land use over the last 30 years. Using the climate data record we looked at the drivers of this change. The sensitivity of the basin to climate change was assessed using the multi-linear regression analysis on the covariance of the change in key phenology parameters and the two climate drivers considered here. The overall response was very complex owing to the complicated climate regime and topography of the region. Vegetation response was mostly stable in high lands with a slightly decreasing trend over low and mid-elevations. Over the same period we also observed an intensification of agriculture production corresponding to an increase in percent cover and productivity. We also observed a decrease in forest cover associated with land use conversion. These changes were mostly driven by the precipitation regimes with little impact of the temperature. Climate models project an eventual decrease in precipitation and increase in temperature over the basin. Coupled with these results and observations these projected changes point to major challenges to the vegetation cover, productivity, and associated ecosystem services of the Nile basin.

  9. Responses of tropical root crops to climate change: implications for Pacific food security

    NASA Astrophysics Data System (ADS)

    Gleadow, R.; Webber, B.; Macness, N.; Lisson, S.; Nauluvula, P.; Hargraves, J.; Crimp, S. J.

    2013-12-01

    Cassava and taro are an important source of calories in many parts of the developing world and hold much promise for meeting the need for food security in equatorial regions. Communities in the Pacific Island countries reliant on agriculture-based livelihood systems have been identified as particularly at risk from climate change, due to likely increases in crop failure, new patterns of pests and diseases, lack of appropriate seed and plant material, loss of livestock and potential loss of arable land. Recent shortfalls in agricultural production resulting from changing export markets, commodity prices, climatic variation, and population growth and urbanisation, have contributed further to regional food insecurity concerns. Cassava and taro contain herbivore defense chemicals that are detrimental to human health (cyanogenic glucosides and calcium oxalate). Unprocessed cassava can cause acute cyanide intoxication, paralysis and even death, especially during droughts. A number of activities are already underway in the Pacific region to identify ways to ameliorate existing climate risk and enhance current agricultural production. Whilst these activities are important to ensure long-term agricultural sustainability, there remains a significant degree of uncertainty as to how effective these strategies may be in the face of a changing and increasingly variable future climate. We present our current understanding of the impact of climate change on key Pacific production systems - specifically those based on the staple root crops, taro and cassava. This includes (1) Our understanding of the responses of cassava and taro crops to existing environmental drivers (climate, soil and nutrient interactions); (2) The responses of cassava and taro crops to enhanced CO2 conditions; and (3) Efforts to model productivity responses (within the APSIM framework) and results for locations in the Pacific.

  10. Engaging Storm Spotters and Community College Students in Regional Responses to Climate Change

    NASA Astrophysics Data System (ADS)

    Mooney, M. E.; Ackerman, S. A.; Buhr, S. M.

    2012-12-01

    Resiliency to natural hazards includes climate literacy. With a record number of billion dollar weather disasters in 2011, each one enhanced by a warmer atmosphere, our nation needs new strategies to respond, mitigate, communicate and adapt to the impacts of climate change. We know that actions we take today matter, but finding ways to mobilize our citizenry remains largely elusive. One way to galvanize a meaningful response to climate change could involve National Weather Service (NWS) storm spotters and Community College students. Dedicated storm spotters represent decades of NOAA NWS efforts to engage and enlist public participation in community safety. Why not leverage this wealth of human capital to cultivate a similar mitigation and stewardship response? The Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison conducted a pilot project with NWS storm spotters in the spring of 2011 via a web seminar on climate change, climate mitigation and emerging applications to access weather and climate data with mobile devices. Nineteen storm spotters participated and eleven provided feedback via a follow-up survey. A third of the respondents indicated that they had taken actions to minimize their carbon footprint; a majority (90%) indicated their likelihood to take action in the near future and more than two-thirds said they wanted to learn more about climate mitigation and sustainability. One attendee commented "Thank-you for putting together this web seminar. As a weather spotter, I found the information helpful, even humbling, to know climate change is already happening." CIMSS is also collaborating with the Cooperative Institute for Research in Environmental Sciences (CIRES) and Madison Area Technical College (MATC) on a climate education project where community college students take an on-line climate change course followed by the opportunity to apply for a summer internship. Through this program, two students

  11. A Hierarchical Modeling Approach to Simulating the Geomorphic Response of River Systems to Climate Change

    NASA Astrophysics Data System (ADS)

    Praskievicz, S. J.

    2014-12-01

    Anthropogenic climate change is expected to change the discharge and sediment-transport regime of river systems. Because rivers adjust their channels to accommodate their typical inputs of water and sediment, changes in these variables can potentially alter river morphology. Here, I developed and applied a hierarchical modeling approach to examine potential changes in reach-averaged bedload transport and spatial patterns of erosion and deposition for three snowmelt-dominated gravel-bed rivers in the interior Pacific Northwest (the Tucannon River in southeastern Washington and the South Fork Coeur d'Alene and Red rivers in Idaho). The modeling hierarchy was based on discharge and suspended-sediment load from a basin-scale hydrologic model driven by a range of downscaled climate-change scenarios. In the field, I collected channel morpholohy and sediment grain-size data for all three rivers. To estimate changes in reach-averaged bedload transport, I used the Bedload Assessment of Gravel-bedded Streams (BAGS) software. I then used the Cellular Automaton Evolutionary Slope and River (CAESAR) model to simulate the spatial pattern of erosion and deposition within each reach to infer potential changes in channel geometry and planform. Results from the BAGS sediment-transport formulas indicate that changes in the duration of the critical discharge needed to mobilize bed sediments are the primary drivers of changes in reach-averaged sediment transport. CAESAR modeling results include changes in river morphology for the two higher-energy river reaches, but no significant morphological changes for a lower-energy reach with steep, cohesive banks, suggesting that the geomorphic response of river systems to climate change may depend on how reach characteristics affect a river's relative stability or mobility. Changes in sediment transport and river morphology resulting from climate change could affect the management of river systems for human and ecological uses.

  12. Sundangrass reproductive biomass responses under climate change scenarios in oak savannah and mesic prairie mesocosm communities

    EPA Science Inventory

    Potential climate change effects include shifts in the distribution of plant species and changes in reproductive output. We tested the hypothesis that environmental stressors such as elevated temperature and drought that are associated with climate change would increase the repr...

  13. Detecting cross-equatorial wind change as a fingerprint of climate response to anthropogenic aerosol forcing

    NASA Astrophysics Data System (ADS)

    Wang, Hai; Xie, Shang-Ping; Tokinaga, Hiroki; Liu, Qinyu; Kosaka, Yu

    2016-04-01

    Anthropogenic aerosols are a major driver of the twetieth century climate change. In climate models, the aerosol forcing, larger in the Northern than Southern Hemispheres, induces an interhemispheric Hadley circulation. In support of the model result, we detected a robust change in the zonal mean cross-equatorial wind over the past 60 years from ship observations and reanalyses, accompanied by physically consistent changes in atmospheric pressure and marine cloud cover. Single-forcing experiments indicate that the observed change in cross-equatorial wind is a fingerprint of aerosol forcing. This zonal mean mode follows the evolution of global aerosol forcing that is distinct from regional changes in the Atlantic sector. Atmospheric simulations successfully reproduce this interhemispheric mode, indicating the importance of sea surface temperature mediation in response to anthropogenic aerosol forcing. As societies awaken to reduce aerosol emissions, a phase reversal of this interhemispheric mode is expected in the 21st century.

  14. Policy strategies to address sustainability of Alaskan boreal forests in response to a directionally changing climate

    PubMed Central

    Chapin, F. Stuart; Lovecraft, Amy L.; Zavaleta, Erika S.; Nelson, Joanna; Robards, Martin D.; Kofinas, Gary P.; Trainor, Sarah F.; Peterson, Garry D.; Huntington, Henry P.; Naylor, Rosamond L.

    2006-01-01

    Human activities are altering many factors that determine the fundamental properties of ecological and social systems. Is sustainability a realistic goal in a world in which many key process controls are directionally changing? To address this issue, we integrate several disparate sources of theory to address sustainability in directionally changing social–ecological systems, apply this framework to climate-warming impacts in Interior Alaska, and describe a suite of policy strategies that emerge from these analyses. Climate warming in Interior Alaska has profoundly affected factors that influence landscape processes (climate regulation and disturbance spread) and natural hazards, but has only indirectly influenced ecosystem goods such as food, water, and wood that receive most management attention. Warming has reduced cultural services provided by ecosystems, leading to some of the few institutional responses that directly address the causes of climate warming, e.g., indigenous initiatives to the Arctic Council. Four broad policy strategies emerge: (i) enhancing human adaptability through learning and innovation in the context of changes occurring at multiple scales; (ii) increasing resilience by strengthening negative (stabilizing) feedbacks that buffer the system from change and increasing options for adaptation through biological, cultural, and economic diversity; (iii) reducing vulnerability by strengthening institutions that link the high-latitude impacts of climate warming to their low-latitude causes; and (iv) facilitating transformation to new, potentially more beneficial states by taking advantage of opportunities created by crisis. Each strategy provides societal benefits, and we suggest that all of them be pursued simultaneously. PMID:17008403

  15. Temperature tracking by North Sea benthic invertebrates in response to climate change.

    PubMed

    Hiddink, Jan G; Burrows, Michael T; García Molinos, Jorge

    2015-01-01

    Climate change is a major threat to biodiversity and distributions shifts are one of the most significant threats to global warming, but the extent to which these shifts keep pace with a changing climate is yet uncertain. Understanding the factors governing range shifts is crucial for conservation management to anticipate patterns of biodiversity distribution under future anthropogenic climate change. Soft-sediment invertebrates are a key faunal group because of their role in marine biogeochemistry and as a food source for commercial fish species. However, little information exists on their response to climate change. Here, we evaluate changes in the distribution of 65 North Sea benthic invertebrate species between 1986 and 2000 by examining their geographic, bathymetric and thermal niche shifts and test whether species are tracking their thermal niche as defined by minimum, mean or maximum sea bottom (SBT) and surface (SST) temperatures. Temperatures increased in the whole North Sea with many benthic invertebrates showing north-westerly range shifts (leading/trailing edges as well as distribution centroids) and deepening. Nevertheless, distribution shifts for most species (3.8-7.3 km yr(-1) interquantile range) lagged behind shifts in both SBT and SST (mean 8.1 km yr(-1)), resulting in many species experiencing increasing temperatures. The velocity of climate change (VoCC) of mean SST accurately predicted both the direction and magnitude of distribution centroid shifts, while maximum SST did the same for contraction of the trailing edge. The VoCC of SBT was not a good predictor of range shifts. No good predictor of expansions of the leading edge was found. Our results show that invertebrates need to shift at different rates and directions to track the climate velocities of different temperature measures, and are therefore lagging behind most temperature measures. If these species cannot withstand a change in thermal habitat, this could ultimately lead to a drop in

  16. Forests, fire, floods and fish: nonlinear biophysical responses to changing climate

    NASA Astrophysics Data System (ADS)

    Pierce, J. L.; Baxter, C.; Yager, E. M.; Fremier, A. K.; Crosby, B. T.; Smith, A. M.; Kennedy, B.; Hicke, J. A.; Feris, K.

    2009-12-01

    consequences for organisms, and 6) how hypothesized shifts in climate-related forces alter the function and resiliency of the Salmon River ecosystem. Integrated approaches include the application of legacy datasets, the exploration of historic chemical and physical records of ecosystem change, intensive stream, riparian and forest monitoring, the use of paired experimental watershed approaches, and the development of spatial analysis tools. If feedbacks among geomorphic, hydrologic and ecologic systems are positive this suggests a possible state change in response to a changing climate.

  17. Exploring the universal ecological responses to climate change in a univoltine butterfly.

    PubMed

    Fenberg, Phillip B; Self, Angela; Stewart, John R; Wilson, Rebecca J; Brooks, Stephen J

    2016-05-01

    Animals with distinct life stages are often exposed to different temperatures during each stage. Thus, how temperature affects these life stages should be considered for broadly understanding the ecological consequences of climate warming on such species. For example, temperature variation during particular life stages may affect respective change in body size, phenology and geographic range, which have been identified as the "universal" ecological responses to climate change. While each of these responses has been separately documented across a number of species, it is not known whether each response occurs together within a species. The influence of temperature during particular life stages may help explain each of these ecological responses to climate change. Our goal was to determine if monthly temperature variation during particular life stages of a butterfly species can predict respective changes in body size and phenology. We also refer to the literature to assess if temperature variability during the adult stage influences range change over time. Using historical museum collections paired with monthly temperature records, we show that changes in body size and phenology of the univoltine butterfly, Hesperia comma, are partly dependent upon temporal variation in summer temperatures during key stages of their life cycle. June temperatures, which are likely to affect growth rate of the final larval instar, are important for predicting adult body size (for males only; showing a positive relationship with temperature). July temperatures, which are likely to influence the pupal stage, are important for predicting the timing of adult emergence (showing a negative relationship with temperature). Previous studies show that August temperatures, which act on the adult stage, are linked to range change. Our study highlights the importance of considering temperature variation during each life stage over historic time-scales for understanding intraspecific response to

  18. Does an understanding of ecosystems responses to rainfall pulses improve predictions of responses of drylands to climate change?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drylands will experience more intense and frequent droughts and floods. Ten-year field experiments manipulating the amount and variability of precipitation suggest that we cannot predict responses of drylands to climate change based on pulse experimentation. Long-term drought experiments showed no e...

  19. Hydrological response to changing climate conditions: Spatial streamflow variability in the boreal region

    NASA Astrophysics Data System (ADS)

    Teutschbein, Claudia; Grabs, Thomas; Karlsen, Reinert H.; Laudon, Hjalmar; Bishop, Kevin

    2016-04-01

    It has long been recognized that streamflow-generating processes are not only dependent on climatic conditions, but also affected by physical catchment properties such as topography, geology, soils and land cover. We hypothesize that these landscape characteristics do not only lead to highly variable hydrologic behavior of rather similar catchments under the same stationary climate conditions (Karlsen et al., 2014), but that they also play a fundamental role for the sensitivity of a catchment to a changing climate (Teutschbein et al., 2015). A multi-model ensemble based on 15 regional climate models was combined with a multi-catchment approach to explore the hydrologic sensitivity of 14 partially nested and rather similar catchments in Northern Sweden to changing climate conditions and the importance of small-scale spatial variability. Current (1981-2010) and future (2061-2090) streamflow was simulated with the HBV model. As expected, projected increases in temperature and precipitation resulted in increased total available streamflow, with lower spring and summer flows, but substantially higher winter streamflow. Furthermore, significant changes in flow durations with lower chances of both high and low flows can be expected in boreal Sweden in the future. This overall trend in projected streamflow pattern changes was comparable among the analyzed catchments while the magnitude of change differed considerably. This suggests that catchments belonging to the same region can show distinctly different degrees of hydrological responses to the same external climate change signal. We reason that differences in spatially distributed physical catchment properties at smaller scales are not only of great importance for current streamflow behavior, but also play a major role as first-order control for the sensitivity of catchments to changing climate conditions. References Karlsen, R.H., T. Grabs, K. Bishop, H. Laudon, and J. Seibert (2014). Landscape controls on

  20. Hydrological response to changing climate conditions: Spatial streamflow variability in the boreal region

    NASA Astrophysics Data System (ADS)

    Teutschbein, C.; Grabs, T.; Karlsen, R. H.; Laudon, H.; Bishop, K.

    2015-12-01

    In this paper we combined a multimodel ensemble based on 15 regional climate models with a multicatchment approach to explore the hydrologic sensitivity of 14 neighboring and rather similar catchments to changing climate conditions. Current (1982-2010) and future (2062-2090) streamflow was simulated with the HBV model. A diagnostic approach was used, which considered major behavioral catchment functions by using hydrologically relevant signatures related to overall water balance, flow duration curves and hydrograph attributes. Projected increases in temperature and precipitation resulted in increased total available streamflow, with lower spring and summer flows, but substantially higher winter streamflow. Furthermore, significant changes in flow durations with lower chances of both high and low flows can be expected in boreal Sweden in the future. This overall trend in projected streamflow pattern changes was comparable among the analyzed catchments but the magnitude of change differed considerably. This suggests that catchments belonging to the same region can show distinctly different degrees of hydrological responses to the same external climate change signal. We reason that differences in spatially distributed physical catchment properties within catchments are not only of great importance for current streamflow behavior, but also play a major role in the sensitivity of catchments to changing climate conditions.

  1. Monsoons and Their Response to Climate Change in Idealized GCM Experiments

    NASA Astrophysics Data System (ADS)

    Laraia, A.; Bordoni, S.

    2014-12-01

    Monsoons are prominent features of the tropical and subtropical atmospheric circulation, affecting 60% of the world's population (Wang 2006) and sustaining rapidly growing economies. Understanding how monsoons will change with changing climate is of pressing societal importance, and yet remains a challenge: Numerous studies have explored the impact of global warming on monsoons, but many questions remain unanswered. In this study, we perform experiments with an idealized General Circulation Model (GCM) to investigate the response of an idealized monsoon to climate change. We focus on two idealized continental geometries, an Africa-like continent stretching from pole to pole with a fixed longitudinal width, and an Asia-like continent that spans all longitudes north of 10°N. The climate is varied by perturbing the atmospheric longwave absorber, in analogy to changes in greenhouse gas concentrations. We use the moist static energy, moisture and zonal momentum budgets (e.g., Chou et al. 2001, Bordoni and Schneider 2008) to interpret the simulated changes in monsoon onset, circulation strength and precipitation. Each budget is decomposed into mean, stationary and transient eddy fluxes, to explore the relative role of these circulations in the maintenance of the monsoonal precipitation. We specifically focus on how the distribution, both spatially and temporally, of precipitation changes as the climate is varied in the two different continental configurations.

  2. Vegetation response to climate change in Alaska: examples from the fossil record

    USGS Publications Warehouse

    Ager, Thomas A.

    2007-01-01

    Preface: This report was presented as an invited paper at the Fish & Wildlife Service Climate Forum held in Anchorage, Alaska on February 21-23, 2007. The purpose of the talk was to provide some examples of past climate changes that appear to have caused significant responses in Alaskan vegetation. These examples are based on interpretations of dated fossil assemblages (pollen, spores and plant macrofossils) collected and interpreted by U.S. Geological Survey and collaborating scientists from other scientific organizations during the past several decades.

  3. Mechanisms that Amplify, Attenuate and Deviate Glacier Response to Climate Change in Central East Greenland. (Invited)

    NASA Astrophysics Data System (ADS)

    Jiskoot, H.

    2013-12-01

    A multidecadal review of glacier fluctuations and case-studies of glacier processes and environments in central East Greenland will be used to demonstrate Mechanisms that Amplify, Attenuate and Deviate glacier response to climate forcings (MAAD). The different spatial and temporal scales at which MAAD affect mass balance and ice flow may complicate interpretation and longterm extrapolation of glacier response to climate change. A framework of MAAD characterisation and best-practice for interpreting climate signals while taking into account MAAD will be proposed. Glaciers in the Watkins Bjerge, Geikie Plateau and Stauning Alps regions of central East Greenland (68°-72°N) contain about 50000 km2 of glacierized area peripheral to the Greenland Ice Sheet. Within the region, large north-south and coast-inland climatic gradients, as well as complicated topography and glacier dynamics, result in discrepant glacier behaviour. Average retreat rates have doubled from about 2 to 4 km2 a-1 between the late 20th and early 21st centuries. However, glaciers terminating along the Atlantic coast display two times the retreat, thinning, and acceleration rates compared to glaciers terminating in inland fjords or on land. Despite similar climatic forcing variable glacier behaviour is apparent: individual glacier length change ranges from +57 m a-1 to -428 m a-1, though most retreat -20 to -100 m a-1. Interacting dynamic, mass balance and glacio-morphological mechanisms can amplify, attenuate or deviate glacier response (MAAD) to climate change, thus complicating the climatological interpretation of glacier length, area, and thickness changes. East Greenland MAAD include a range of common positive and negative feedback mechanisms in surface mass balance and terminus and subglacial boundary conditions affecting ice flow, but also mechanisms that have longterm or delayed effects. Certain MAAD may affect glacier change interpretation on multiple timescales: e.g. surging glaciers do not

  4. Simulated annual changes in plant functional types and their responses to climate change on the northern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Cuo, Lan; Zhang, Yongxin; Piao, Shilong; Gao, Yanhong

    2016-06-01

    Changes in plant functional types (PFTs) have important implications for both climate and water resources. Still, little is known about whether and how PFTs have changed over the past decades on the northern Tibetan Plateau (NTP) where several of the top largest rivers in the world are originated. Also, the relative importance of atmospheric conditions vs. soil physical conditions in affecting PFTs is unknown on the NTP. In this study, we used the improved Lund-Potsdam-Jena Dynamic Global Vegetation Model to investigate PFT changes through examining the changes in foliar projective coverages (FPCs) during 1957-2009 and their responses to changes in root zone soil temperature, soil moisture, air temperature, precipitation and CO2 concentrations. The results show spatially heterogeneous changes in FPCs across the NTP during 1957-2009, with 34 % (13 %) of the region showing increasing (decreasing) trends. Dominant drivers responsible for the observed FPC changes vary with regions and vegetation types, but overall, precipitation is the major factor in determining FPC changes on the NTP with positive impacts. Soil temperature increase exhibits small but negative impacts on FPCs. Different responses of individual FPCs to regionally varying climate change result in spatially heterogeneous patterns of vegetation changes on the NTP. The implication of the study is that fresh water resources in one of the world's largest and most important headwater basins and the onset and intensity of Asian monsoon circulations could be affected because of the changes in FPCs on the NTP.

  5. Modeling the Hydrological Response to Climate Change in an Arid Inland River Basin

    NASA Astrophysics Data System (ADS)

    Zheng, C.; Zhang, A.; Tian, Y.; Zheng, Y.; Liu, J.

    2014-12-01

    Located deep in the hinterlands of Eurasia, the Heihe River Basin (HRB) is an arid inland river basin in northwest China where the hydrologic regime responds sensitively to climate change. From the headwater region to terminal lakes, the HRB can be roughly divided into three sections, i.e., the upstream Qilian Mountains, the midstream oases and the downstream Gobi Desert. Runoff generated in the upstream mountainous terrains, dominated by climate variations, is the critical water resource for the whole river basin. With increasing intensification of climate change, there is an urgent need to understand future changes of water resources and water-related disasters to support regional water management. This study investigates the potential impact of climate change on hydrologic processes in the upper HRB for the future period of 2021~2150. Downscaled temperature and precipitation projections from six General Circulation Models under two emission scenarios (RCP4.5 and RCP8.5) are adopted to drive a commonly used flow model, Soil Water Assessment Tool (SWAT), for the upper HRB. The impacts of climate change on the total runoff and its components are quantified based on the future climate scenario analysis and the results of SWAT simulation. To understand how the climate change affects the availability and distribution of water resources in the middle and lower HRB where irrigated agriculture and ecosystem conservation compete for water resources, runoffs from the upper HRB are used as the boundary conditions for an integrated groundwater-surface water model based on the USGS GSFLOW for the middle and lower HRB. The integrated model assimilated multiple types of data including groundwater levels at monitoring wells, streamflow at gaging stations, and evapotranspiration (ET) derived from remote sensing data. The calibrated model was able to adequately reproduce the observed hydrological variables. The integrated model was then used to assess the potential response of the

  6. Beyond Adapting to Climate Change: Embedding Adaptation in Responses to Multiple Threats and Stresses

    SciTech Connect

    Wilbanks, Thomas J; Kates, Dr. Robert W.

    2010-01-01

    Climate change impacts are already being experienced in every region of the United States and every part of the world most severely in Arctic regions and adaptation is needed now. Although climate change adaptation research is still in its infancy, significant adaptation planning in the United States has already begun in a number of localities. This article seeks to broaden the adaptation effort by integrating it with broader frameworks of hazards research, sustainability science, and community and regional resilience. To extend the range of experience, we draw from ongoing case studies in the Southeastern United States and the environmental history of New Orleans to consider the multiple threats and stresses that all communities and regions experience. Embedding climate adaptation in responses to multiple threats and stresses helps us to understand climate change impacts, themselves often products of multiple stresses, to achieve community acceptance of needed adaptations as co-benefits of addressing multiple threats, and to mainstream the process of climate adaptation through the larger envelope of social relationships, communication channels, and broad-based awareness of needs for risk management that accompany community resilience.

  7. Imbedding dynamic responses with imperfect information into static portraits of the regional impact of climate change

    SciTech Connect

    Yohe, G.W. )

    1990-11-01

    It is becoming increasingly clear, at least on a theoretical level, that modelers of the potential impacts of climate change must impose that change upon the world as it will be configured sometime in the future rather than confine their attention to considerations of what would happen to the world as it looks now. Initial baselines which focus on current circumstances are certainly worthwhile points of departure in any study, of course, but the truth is that social, economic, and political systems will evolve as the future unfolds; and careful analysis of that evolution across a globe experiencing changes in its climate must be undertaken, as well. In the vernacular of the analysts' workroom, while it may be interesting to try to see what would happen to dumb farmers'' who continue to do things as they always have regardless of what happens, it is critically important to evaluate the need for any sort of policy response to climate change in a world of smart farmers'' who will have observed the ramifications of climate change and responded in their own best interest. 9 refs., 2 figs.

  8. Climate change, phenological shifts, eco-evolutionary responses and population viability: toward a unifying predictive approach.

    PubMed

    Jenouvrier, Stéphanie; Visser, Marcel E

    2011-11-01

    The debate on emission targets of greenhouse gasses designed to limit global climate change has to take into account the ecological consequences. One of the clearest ecological consequences is shifts in phenology. Linking these shifts to changes in population viability under various greenhouse gasses emission scenarios requires a unifying framework. We propose a box-in-a-box modeling approach that couples population models to phenological change. This approach unifies population modeling with both ecological responses to climate change as well as evolutionary processes. We advocate a mechanistic embedded correlative approach, where the link from genes to population is established using a periodic matrix population model. This periodic model has several major advantages: (1) it can include complex seasonal behaviors allowing an easy link with phenological shifts; (2) it provides the structure of the population at each phase, including the distribution of genotypes and phenotypes, allowing a link with evolutionary processes; and (3) it can incorporate the effect of climate at different time periods. We believe that the way climatologists have approached the problem, using atmosphere-ocean coupled circulation models in which components are gradually included and linked to each other, can provide a valuable example to ecologists. We hope that ecologists will take up this challenge and that our preliminary modeling framework will stimulate research toward a unifying predictive model of the ecological consequences of climate change. PMID:21710282

  9. Genetic response to climatic change: insights from ancient DNA and phylochronology.

    PubMed

    Hadly, Elizabeth A; Ramakrishnan, Uma; Chan, Yvonne L; van Tuinen, Marcel; O'Keefe, Kim; Spaeth, Paula A; Conroy, Chris J

    2004-10-01

    Understanding how climatic change impacts biological diversity is critical to conservation. Yet despite demonstrated effects of climatic perturbation on geographic ranges and population persistence, surprisingly little is known of the genetic response of species. Even less is known over ecologically long time scales pertinent to understanding the interplay between microevolution and environmental change. Here, we present a study of population variation by directly tracking genetic change and population size in two geographically widespread mammal species (Microtus montanus and Thomomys talpoides) during late-Holocene climatic change. We use ancient DNA to compare two independent estimates of population size (ecological and genetic) and corroborate our results with gene diversity and serial coalescent simulations. Our data and analyses indicate that, with population size decreasing at times of climatic change, some species will exhibit declining gene diversity as expected from simple population genetic models, whereas others will not. While our results could be consistent with selection, independent lines of evidence implicate differences in gene flow, which depends on the life history strategy of species. PMID:15361933

  10. Terrestrial Vegetation Response to Climate Change Over North America from Increased Atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Ming, M.; Mao, H.; Talbot, R.

    2005-12-01

    We used a regional climate version of the MM5 mesoscale atmospheric modeling system that was asynchronically and simultaneously coupled with the biogeographical model BIOME to explore vegetation-climate interactions over North America. The impact of climate change due to increased greenhouse gases on potential ecosystem evolution was assessed, and a future scenario of vegetation distribution was explored. Doubled CO2 conditions induced strong high-latitude warming, while the southern U.S. became cooler in winter. Across almost all of the model domain precipitation tended to increase in all seasons with the highest intensification found over the Northeast, Southeast, and the Great Plains. In response to this future climate scenario, vegetation migrated northward systematically in the eastern United States. In particular, the sparsely vegetated area around Hudson Bay was predicted to be covered by cool conifer forests. Over the Great Plains and parts of the Midwest, the supply of water from precipitation was found to be a crucial factor affecting the natural evolution of vegetation; more precipitation under doubled CO2 led to temperate deciduous forests extending northward and to the northwest. Grasslands in the northern half of the Great Plains are expected to be replaced by cool conifer and mixed forests due to increased precipitation. Over the Cascade and Rocky Mountain ranges in the western U.S., no systematic changes in vegetation are predicted, due to the complex terrain and unsystematic changes in temperature and precipitation. Averaged over the whole model domain, 39% of areas are projected to have vegetation type changes under doubled CO2. The above results were obtained with model simulations using 108 km resolution, and they will be compared with runs using 50 km resolution to study the potential impact of model resolution on regional ecosystem response to climate change.

  11. Hydrologic response to forest cover changes following a Mountain Pine Beetle outbreak in the context of a changing climate

    NASA Astrophysics Data System (ADS)

    Moore, Dan; Jost, Georg; Nelson, Harry; Smith, Russell

    2013-04-01

    Over the last 15 years, there has been extensive mortality of pine forests in western North America associated with an outbreak of Mountain Pine Beetle, often followed by salvage logging. The objective of this study was to quantify the separate and combined effects of forest recovery and climate change over the 21st century on catchment hydrology in the San Jose watershed, located in the semi-arid Interior Plateau of British Columbia. Forest cover changes were simulated using a dynamic spatial model that uses a decentralized planning approach. We implemented management strategies representing current timber management objectives around achieving targeted harvest levels and incorporating existing management constraints under two different scenarios, one with no climate change and one under climate change, using climate-adjusted growth and yield curves. In addition, higher rates of fire disturbance were modelled under climate change. Under climate change, while productivity improves for some species (mainly Douglas-fir on better quality sites), on drier and poorer quality sites most species, especially Lodgepole Pine, become significantly less productive, and stocking is reduced to the point that those sites transition into grasslands. The combined effect of initial age classes (where the forest has been severely impacted by MPB), increased fire, and reduced stocking results in a greater proportion of the forest in younger age classes compared to a "Business As Usual" scenario with no climate change. The hydrologic responses to changes in vegetation cover and climate were evaluated with the flexible Hydrology Emulator and Modelling Platform (HEMP) developed at the University of British Columbia. HEMP allows a flexible discretization of the landscape. Water is moved vertically within landscape units by processes such as precipitation, canopy interception and soil infiltration, and routed laterally between units as a function of local soil and groundwater storage. The

  12. Biomass allocation of montane and desert Pondersoa Pine: An analog for response to climate change

    SciTech Connect

    Callaway, R.M.; DeLucia, E.H. ); Schlesinger, W.H. )

    1994-07-01

    Aboveground biomass allocation of Pinus ponderosa on hydrothermally altered andesite in montane and desert climates was measured. Trees from montane climates had higher leaf mass per unit cross-sectional area of sapwood than trees from desert climates, suggesting a function response to differences in climate. Results also indicate that sapwood mass:leaf mass ratios of P. ponderosa may increase [approx]50% with a 5[degrees]C change in mean growing-season temperature. High proportional allocation of biomass to sapwood may improve water relations of P. ponderosa, but because sapwood contains living parenchyma, respiratory costs may be high. Simulated montane trees were 46-52% taller than desert trees, and montane trees 10 cm in dbh had twice the total aboveground mass of desert counterparts. Simulated 50-cm montane and desert trees were almost identical in total mass, even though the montane tree was 46% taller. The predicted proportion of biomass allocated to bole sapwood increased with size for both montane and desert models; however, the 50-cm desert model contained 8% more total sapwood mass than the taller montane model. Biomass of primary and secondary branches differed considerably. The 50-cm desert model had twice as much biomass in primary branches, whereas the montane model had 3 times more biomass in secondary branches than the desert model. For 10-cm trees of the desert and montane models 29 and 33% of the biomass were leaves, respectively. In larger trees, leaf allocation decreased to 5 and 7% for desert and montane models, respectively. The effects of climate on biomass allocation such as reported here, and corresponding changes in whole-plant assimilation rates must be incorporated into growth-response models used to predict future fluctuations in forest productivity due to global climate change. 35 refs., 3 figs., 3 tabs.

  13. Nonlinear flowering responses to climate: are species approaching their limits of phenological change?

    PubMed Central

    Iler, Amy M.; Høye, Toke T.; Inouye, David W.; Schmidt, Niels M.

    2013-01-01

    Many alpine and subalpine plant species exhibit phenological advancements in association with earlier snowmelt. While the phenology of some plant species does not advance beyond a threshold snowmelt date, the prevalence of such threshold phenological responses within plant communities is largely unknown. We therefore examined the shape of flowering phenology responses (linear versus nonlinear) to climate using two long-term datasets from plant communities in snow-dominated environments: Gothic, CO, USA (1974–2011) and Zackenberg, Greenland (1996–2011). For a total of 64 species, we determined whether a linear or nonlinear regression model best explained interannual variation in flowering phenology in response to increasing temperatures and advancing snowmelt dates. The most common nonlinear trend was for species to flower earlier as snowmelt advanced, with either no change or a slower rate of change when snowmelt was early (average 20% of cases). By contrast, some species advanced their flowering at a faster rate over the warmest temperatures relative to cooler temperatures (average 5% of cases). Thus, some species seem to be approaching their limits of phenological change in response to snowmelt but not temperature. Such phenological thresholds could either be a result of minimum springtime photoperiod cues for flowering or a slower rate of adaptive change in flowering time relative to changing climatic conditions. PMID:23836793

  14. Methods for Assessing Uncertainties in Climate Change, Impacts and Responses (Invited)

    NASA Astrophysics Data System (ADS)

    Manning, M. R.; Swart, R.

    2009-12-01

    Assessing the scientific uncertainties or confidence levels for the many different aspects of climate change is particularly important because of the seriousness of potential impacts and the magnitude of economic and political responses that are needed to mitigate climate change effectively. This has made the treatment of uncertainty and confidence a key feature in the assessments carried out by the Intergovernmental Panel on Climate Change (IPCC). Because climate change is very much a cross-disciplinary area of science, adequately dealing with uncertainties requires recognition of their wide range and different perspectives on assessing and communicating those uncertainties. The structural differences that exist across disciplines are often embedded deeply in the corresponding literature that is used as the basis for an IPCC assessment. The assessment of climate change science by the IPCC has from its outset tried to report the levels of confidence and uncertainty in the degree of understanding in both the underlying multi-disciplinary science and in projections for future climate. The growing recognition of the seriousness of this led to the formation of a detailed approach for consistent treatment of uncertainties in the IPCC’s Third Assessment Report (TAR) [Moss and Schneider, 2000]. However, in completing the TAR there remained some systematic differences between the disciplines raising concerns about the level of consistency. So further consideration of a systematic approach to uncertainties was undertaken for the Fourth Assessment Report (AR4). The basis for the approach used in the AR4 was developed at an expert meeting of scientists representing many different disciplines. This led to the introduction of a broader way of addressing uncertainties in the AR4 [Manning et al., 2004] which was further refined by lengthy discussions among many IPCC Lead Authors, for over a year, resulting in a short summary of a standard approach to be followed for that

  15. Adaptive Governance, Uncertainty, and Risk: Policy Framing and Responses to Climate Change, Drought, and Flood.

    PubMed

    Hurlbert, Margot; Gupta, Joyeeta

    2016-02-01

    As climate change impacts result in more extreme events (such as droughts and floods), the need to understand which policies facilitate effective climate change adaptation becomes crucial. Hence, this article answers the question: How do governments and policymakers frame policy in relation to climate change, droughts, and floods and what governance structures facilitate adaptation? This research interrogates and analyzes through content analysis, supplemented by semi-structured qualitative interviews, the policy response to climate change, drought, and flood in relation to agricultural producers in four case studies in river basins in Chile, Argentina, and Canada. First, an epistemological explanation of risk and uncertainty underscores a brief literature review of adaptive governance, followed by policy framing in relation to risk and uncertainty, and an analytical model is developed. Pertinent findings of the four cases are recounted, followed by a comparative analysis. In conclusion, recommendations are made to improve policies and expand adaptive governance to better account for uncertainty and risk. This article is innovative in that it proposes an expanded model of adaptive governance in relation to "risk" that can help bridge the barrier of uncertainty in science and policy. PMID:26630544

  16. Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change

    USGS Publications Warehouse

    Hope, A.G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, S.L.; Cook, J.A.

    2011-01-01

    Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes. ?? 2011 Blackwell Publishing Ltd.

  17. Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change

    USGS Publications Warehouse

    Hope, Andrew G.; Waltari, Eric; Fedorov, V.B.; Goropashnaya, A.V.; Talbot, Sandra; Cook, Joseph A.

    2014-01-01

    Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes.

  18. Persistence and diversification of the Holarctic shrew, Sorex tundrensis (Family Soricidae), in response to climate change.

    PubMed

    Hope, Andrew G; Waltari, Eric; Fedorov, Vadim B; Goropashnaya, Anna V; Talbot, Sandra L; Cook, Joseph A

    2011-10-01

    Environmental processes govern demography, species movements, community turnover and diversification and yet in many respects these dynamics are still poorly understood at high latitudes. We investigate the combined effects of climate change and geography through time for a widespread Holarctic shrew, Sorex tundrensis. We include a comprehensive suite of closely related outgroup taxa and three independent loci to explore phylogeographic structure and historical demography. We then explore the implications of these findings for other members of boreal communities. The tundra shrew and its sister species, the Tien Shan shrew (Sorex asper), exhibit strong geographic population structure across Siberia and into Beringia illustrating local centres of endemism that correspond to Late Pleistocene refugia. Ecological niche predictions for both current and historical distributions indicate a model of persistence through time despite dramatic climate change. Species tree estimation under a coalescent process suggests that isolation between populations has been maintained across timeframes deeper than the periodicity of Pleistocene glacial cycling. That some species such as the tundra shrew have a history of persistence largely independent of changing climate, whereas other boreal species shifted their ranges in response to climate change, highlights the dynamic processes of community assembly at high latitudes. PMID:21919986

  19. Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

    NASA Astrophysics Data System (ADS)

    Adloff, Fanny; Somot, Samuel; Sevault, Florence; Jordà, Gabriel; Aznar, Roland; Déqué, Michel; Herrmann, Marine; Marcos, Marta; Dubois, Clotilde; Padorno, Elena; Alvarez-Fanjul, Enrique; Gomis, Damià

    2015-11-01

    The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air-sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961-2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001-2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air-sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070-2099 period compared to 1961-1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in

  20. Competing Positive and Negative Feedbacks on Glacier Response to Climatic Changes

    NASA Astrophysics Data System (ADS)

    Rupper, S.; Todd, C. E.

    2009-12-01

    The adiabatic temperature lapse rate imparts a well-studied positive feedback on glacier changes in response to a given change in climate. For example, if temperature increases, the surface of the glacier thins into the warmer temperatures of the lower surface elevation, dependent upon the local lapse rate, which amplifies the glacier response to the original temperature. However, a less well-quantified negative feedback can also be at play. As the length and thickness of a valley glacier changes, the percentage of the glacier surface that is shaded changes as well, decreasing the incident shortwave radiation at the surface. Assuming turbulent heat fluxes are small, the balance between changing downward longwave radiation (adiabatic lapse rate effect) and shortwave radiation (shading effect) in response to a climatic change will determine the equilibrium glacier profile for the new climate state. Here we use an energy balance model to determine the sensitivity of glacial retreat reconstructions to both the temperature lapse rate and the shading by valley topography. We quantify the effect of shading and lapse rates on idealized glaciers and topography, and assess under what conditions one or the other feedback mechanism is expected to dominate the change in energy balance. We then examine the effect of temperature lapse rates and increased shading on a paleoglacier at Monroe Peak, in the Sevier Plateau, Utah. Although the peak is currently ice-free, lateral moraines on Monroe Peak show that a glacier once extended approximately 4000 m from a 4700 m high headwall on the western side of the peak. Preliminary results suggest that as the glacier retreated from its maximum position, increased shading had a significant positive effect on glacial mass balance which partially compensated for the lapse rate feedback. These preliminary results suggest that reconstructions of smaller glaciers surrounded by steep topography must account for changes in shading of the glacier

  1. Potential for a hazardous geospheric response to projected future climate changes.

    PubMed

    McGuire, B

    2010-05-28

    Periods of exceptional climate change in Earth history are associated with a dynamic response from the geosphere, involving enhanced levels of potentially hazardous geological and geomorphological activity. The response is expressed through the adjustment, modulation or triggering of a broad range of surface and crustal phenomena, including volcanic and seismic activity, submarine and subaerial landslides, tsunamis and landslide 'splash' waves, glacial outburst and rock-dam failure floods, debris flows and gas-hydrate destabilization. In relation to anthropogenic climate change, modelling studies and projection of current trends point towards increased risk in relation to a spectrum of geological and geomorphological hazards in a warmer world, while observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere. Here, the potential influences of anthropogenic warming are reviewed in relation to an array of geological and geomorphological hazards across a range of environmental settings. A programme of focused research is advocated in order to: (i) understand better those mechanisms by which contemporary climate change may drive hazardous geological and geomorphological activity; (ii) delineate those parts of the world that are most susceptible; and (iii) provide a more robust appreciation of potential impacts for society and infrastructure. PMID:20403831

  2. Soil Microbial Community Responses to Short-term Multiple Experimental Climate Change Drivers

    NASA Astrophysics Data System (ADS)

    Li, Guanlin; Lee, Jongyeol; Lee, Sohye; Roh, Yujin; Son, Yowhan

    2016-04-01

    It is agreed that soil microbial communities are responsible for the cycling of carbon and nutrients in ecosystems; however, the response of these microbial communities to climate change has not been clearly understood. In this study, we measured the direct and interactive effects of climate change drivers on soil bacterial and fungal communities (abundance and composition) in an open-field multifactor climate change experiment. The experimental treatment system was established with two-year-old Pinus densiflora seedlings at Korea University in April 2013, and consisted of six different treatments with three replicates: two levels of air temperature warming (control and +3° C) were crossed with three levels of precipitation manipulation (control, -30% and +30%). After 2.5 years of treatments, in August, 2015, soil samples were collected from the topsoil (0-15cm) of all plots (n=18). High-throughput sequencing technology was used to assess the abundance and composition of soil bacterial and fungal community. Analysis of variance for a blocked split-plot design was used to detect the effects of climate change drivers and their interaction on the abundance and composition of soil bacterial and fungal community. Our results showed that 1) only the significant effect of warming on fungal community abundance was observed (P <0.05); 2) on average, warming decreased both bacterial and fungal community abundance by 20.90% and 32.30%, 6.69% and 45.89%, 14.71% and 19.56% in control, decreased, and increased precipitation plots, respectively; 3) however, warming increased the relative bacterium/fungus ratio on average by 14.03%, 37.03% and 14.31% in control, decreased, and increased precipitation plots, respectively; 4) the phylogenetic distribution of bacterial and fungal groups and their relative abundance varied among treatments; 5) treatments altered the relative abundance of Ascomycota and Basidiomycota, where Ascomycota decreased with a concomitant increase in the

  3. Do cities simulate climate change? A comparison of herbivore response to urban and global warming.

    PubMed

    Youngsteadt, Elsa; Dale, Adam G; Terando, Adam J; Dunn, Robert R; Frank, Steven D

    2015-01-01

    Cities experience elevated temperature, CO2 , and nitrogen deposition decades ahead of the global average, such that biological response to urbanization may predict response to future climate change. This hypothesis remains untested due to a lack of complementary urban and long-term observations. Here, we examine the response of an herbivore, the scale insect Melanaspis tenebricosa, to temperature in the context of an urban heat island, a series of historical temperature fluctuations, and recent climate warming. We survey M. tenebricosa on 55 urban street trees in Raleigh, NC, 342 herbarium specimens collected in the rural southeastern United States from 1895 to 2011, and at 20 rural forest sites represented by both modern (2013) and historical samples. We relate scale insect abundance to August temperatures and find that M. tenebricosa is most common in the hottest parts of the city, on historical specimens collected during warm time periods, and in present-day rural forests compared to the same sites when they were cooler. Scale insects reached their highest densities in the city, but abundance peaked at similar temperatures in urban and historical datasets and tracked temperature on a decadal scale. Although urban habitats are highly modified, species response to a key abiotic factor, temperature, was consistent across urban and rural-forest ecosystems. Cities may be an appropriate but underused system for developing and testing hypotheses about biological effects of climate change. Future work should test the applicability of this model to other groups of organisms. PMID:25163424

  4. Do cities simulate climate change? A comparison of herbivore response to urban and global warming

    USGS Publications Warehouse

    Youngsteadt, Elsa; Dale, Adam G.; Terando, Adam; Dunn, Robert R.; Frank, Steven D.

    2014-01-01

    Cities experience elevated temperature, CO2, and nitrogen deposition decades ahead of the global average, such that biological response to urbanization may predict response to future climate change. This hypothesis remains untested due to a lack of complementary urban and long-term observations. Here, we examine the response of an herbivore, the scale insect Melanaspis tenebricosa, to temperature in the context of an urban heat island, a series of historical temperature fluctuations, and recent climate warming. We survey M. tenebricosa on 55 urban street trees in Raleigh, NC, 342 herbarium specimens collected in the rural southeastern United States from 1895 to 2011, and at 20 rural forest sites represented by both modern (2013) and historical samples. We relate scale insect abundance to August temperatures and find that M. tenebricosa is most common in the hottest parts of the city, on historical specimens collected during warm time periods, and in present-day rural forests compared to the same sites when they were cooler. Scale insects reached their highest densities in the city, but abundance peaked at similar temperatures in urban and historical datasets and tracked temperature on a decadal scale. Although urban habitats are highly modified, species response to a key abiotic factor, temperature, was consistent across urban and rural-forest ecosystems. Cities may be an appropriate but underused system for developing and testing hypotheses about biological effects of climate change. Future work should test the applicability of this model to other groups of organisms.

  5. NDVI-based vegetation responses to climate change in an arid area of China

    NASA Astrophysics Data System (ADS)

    Xu, Yufeng; Yang, Jing; Chen, Yaning

    2015-07-01

    Warming of the climate system is unequivocal, and the change of climate variables will eventually have a great impact on vegetation cover and agricultural practices, especially in the arid area Xinjiang in China, whose agriculture and ecosystems are heavily vulnerable to climate change. In this paper, normalized difference vegetation index (NDVI) was used to study the vegetation growth and its response to climate change in Xinjiang. Firstly, two NDVI datasets (Global Inventory Modeling and Mapping Studies (GIMMS) and Moderate Resolution Imaging Spectroradiometer (MODIS)) were merged through a pixel-wise regression analysis to obtain a long time series of NDVI data, and then, relationships between yearly NDVI and yearly climate variables, and monthly NDVI and monthly climate variables were extensively investigated for grassland and cropland in northern and southern Xinjiang, respectively. Results show the following: (1) there was an increasing trend in NDVI for both grassland and cropland in both northern and southern Xinjiang over the past decades and trends were significant except that for grassland in northern Xinjiang; (2) precipitation and evaporation were more important than temperature for grassland in northern Xinjiang, while precipitation and temperature were more important than evaporation for grassland in southern Xinjiang and cropland in both northern and southern Xinjiang; (3) NDVI was highly correlated with accumulated monthly precipitation instead of monthly precipitation, and there was a lagged effect of precipitation, temperature, and evaporation on NDVI change. However, lagged effects were only significant in specific months. The results could be helpful to agricultural practices; e.g., based on lagged effect of precipitation, irrigation in July is very important for crop growth.

  6. Climate change and apple farming in Indian Himalayas: a study of local perceptions and responses.

    PubMed

    Basannagari, Basavaraj; Kala, Chandra Prakash

    2013-01-01

    Apple farming is an important activity and profession of farmer communities in the Himalayan states of India. At present, the traditional apple farming is under stress due to changes in climate. The present study was undertaken in an Indian Himalayan state, Himachal Pradesh, with the major aim of studying perceptions of farmers on the effects of climate change on apple farming along the altitudinal gradient. Through questionnaire survey, the perceptions of farmers were recorded at low hills (<2500 m), mid-hills (2500-3000 m), and upper hills (>3000 m). At all elevation range the majority of farmers reported that there was increase in atmospheric temperature, and hence at low hills 72% farmers believed that this increase in temperature was responsible for decline in fruit size and so that the quality. Thirty five percent farmers at high hills and 30% at mid hills perceived frost as a major cause for damaging apple farming whereas at low hills 24% farmers perceived hailstorm as the major deterrent for apple farming. The majority of farmers, along the altitude (92% at high hills, 79% at mid hills and 83% at low hills), reported decrease in snowfall. The majority of farmers at low altitude and mid altitude reported decline in apple farming whereas 71% farmers at high hill areas refused decline in apple farming. About 73-83% farmers admitted delay in apple's harvesting period. At mid hills apple scab and at low hills pest attack on apple crops are considered as the indicators of climate change. The change in land use practices was attributed to climate change and in many areas the land under apple farming was replaced for production of coarse grains, seasonal vegetables and other horticulture species. Scientific investigation claiming changes in Indian Himalayan climate corroborates perceptions of farmers, as examined during the present study. PMID:24205051

  7. Population differentiation in tree-ring growth response of white fir (Abies concolor) to climate: Implications for predicting forest responses to climate change

    SciTech Connect

    Jensen, D.B.

    1993-10-01

    Forest succession models and correlative models have predicted 200--650 kilometer shifts in the geographic range of temperate forests and forest species as one response to global climate change. Few studies have investigated whether population differences may effect the response of forest species to climate change. This study examines differences in tree-ring growth, and in the phenotypic plasticity of tree-ring growth in 16-year old white fir, Abies concolor, from ten populations grown in four common gardens in the Sierra Nevada of California. For each population, tree-ring growth was modelled as a function of precipitation and degree-day sums. Tree-ring growth under three scenarios of doubled C0{sub 2} climates was estimated.

  8. Flood Response Modification of A Mountainous Watershed Due To Climate and Vegetation Changes

    NASA Astrophysics Data System (ADS)

    Loukas, A.; Vasiliades, L.; Dalezios, N. R.

    The flood response change due to altered climatic conditions and vegetation changes is analysed for the Illecillewaet watershed located on the western slopes of Rocky Mountain Range of British Columbia, Canada. The output of the second-generation general circulation model of the Canadian Centre for Climate Modeling and Analysis (CGCMa1) was used for the assessment of changes of precipitation and temperature due to climate change. The runoff was simulated using the U.B.C. watershed model and considering, also, changes on the spatial distribution of precipitation with eleva- tion, cloud cover, glaciers, vegetation distribution, vegetation biomass production, and plant physiology. The simulation was performed for a twenty-year period. The period 1970-1990 was the historical recorded period assuming that represents the present cli- mate and the period 2080-2100 represents the altered climatic conditions. The results showed that, on average, the annual basin wide precipitation would increase by about 15% and the temperature by about 4.1?C, under the altered climate. For the study of floods several flood parameters were extracted from the simulated hydrographs and es- timated for present and future climatic conditions using the historical triple long-term mean daily flow as a flood flow threshold. These flood parameters were calculated for the two identified major flood producing mechanisms (flood components) the spring rain and snowmelt runoff and the summer runoff with contribution of glacier melt. The study showed that, under the climate change scenario, the maximum flood peaks for the spring and summer events would reduce by 4% and 2% respectively, whereas the maximum annual flood would decrease, on average, by 11.5%. The total flood volume per year would change by -55% but the flood volume of the two major flood components would remain rather unchanged. The total number of flood episodes is likely to reduce by 43%. The flood episodes for spring and summer events

  9. Fine-scale processes regulate the response of extreme events to global climate change

    NASA Astrophysics Data System (ADS)

    Diffenbaugh, Noah S.; Pal, Jeremy S.; Trapp, Robert J.; Giorgi, Filippo

    2005-11-01

    We find that extreme temperature and precipitation events are likely to respond substantially to anthropogenically enhanced greenhouse forcing and that fine-scale climate system modifiers are likely to play a critical role in the net response. At present, such events impact a wide variety of natural and human systems, and future changes in their frequency and/or magnitude could have dramatic ecological, economic, and sociological consequences. Our results indicate that fine-scale snow albedo effects influence the response of both hot and cold events and that peak increases in extreme hot events are amplified by surface moisture feedbacks. Likewise, we find that extreme precipitation is enhanced on the lee side of rain shadows and over coastal areas dominated by convective precipitation. We project substantial, spatially heterogeneous increases in both hot and wet events over the contiguous United States by the end of the next century, suggesting that consideration of fine-scale processes is critical for accurate assessment of local- and regional-scale vulnerability to climate change. extreme climate | RegCM3 | regional climate model | United States | CO2

  10. Predicted response of stem respiration in ponderosa pine to global climate change

    SciTech Connect

    Carey, E.V.; DeLucia, E.H.; Callaway, R.M. )

    1994-06-01

    We measured woody tissue respiration on boles of desert and montane populations of Pinus ponderosa growing in the Great Basin Desert and on the east-slope of the Sierra Nevada as part of a study of responses of P. ponderosa to global climate change. The differences in temperature and precipitation between desert and montane populations match changes in climate predicted from a doubling of atmospheric CO[sub 2]; therefore, these naturally occurring populations represent the difference between present and future climatic conditions for these trees. Allometric relationships derived previously, indicate that for trees of equal diameter, desert trees predicted that desert trees would have lower Q[sub 10] responses for respiration (increase in respiration with a 10[degrees] increase in temperature) volume was not different between populations (Desert: 3.24; Montane: 3.13 moles m[sup [minus]3] sec[sup [minus]1]). Moreover, between population differences in Q[sub 10] for respiration were not statistically significant (Desert: 2.27; Montane: 2.39). Results suggest that under predicted future climatic conditions increased respiratory losses from woody tissue resulting from increased allocation to sapwood may offset increases in carbon uptake due to enhanced photosynthesis from elevated CO[sub 2].

  11. Lifestyle and Ice: The Relationship between Ecological Specialization and Response to Pleistocene Climate Change

    PubMed Central

    Kašparová, Eva; Van de Putte, Anton P.; Marshall, Craig; Janko, Karel

    2015-01-01

    Major climatic changes in the Pleistocene had significant effects on marine organisms and the environments in which they lived. The presence of divergent patterns of demographic history even among phylogenetically closely-related species sharing climatic changes raises questions as to the respective influence of species-specific traits on population structure. In this work we tested whether the lifestyle of Antarctic notothenioid benthic and pelagic fish species from the Southern Ocean influenced the concerted population response to Pleistocene climatic fluctuations. This was done by a comparative analysis of sequence variation at the cyt b and S7 loci in nine newly sequenced and four re-analysed species. We found that all species underwent more or less intensive changes in population size but we also found consistent differences between demographic histories of pelagic and benthic species. Contemporary pelagic populations are significantly more genetically diverse and bear traces of older demographic expansions than less diverse benthic species that show evidence of more recent population expansions. Our findings suggest that the lifestyles of different species have strong influences on their responses to the same environmental events. Our data, in conjunction with previous studies showing a constant diversification tempo of these species during the Pleistocene, support the hypothesis that Pleistocene glaciations had a smaller effect on pelagic species than on benthic species whose survival may have relied upon ephemeral refugia in shallow shelf waters. These findings suggest that the interaction between lifestyle and environmental changes should be considered in genetic analyses. PMID:26535569

  12. Independent Demographic Responses to Climate Change among Temperate and Tropical Milksnakes (Colubridae: Genus Lampropeltis)

    PubMed Central

    Ruane, Sara; Torres-Carvajal, Omar; Burbrink, Frank T.

    2015-01-01

    The effects of Late Quaternary climate change have been examined for many temperate New World taxa, but the impact of Pleistocene glacial cycles on Neotropical taxa is less well understood, specifically with respect to changes in population demography. Here, we examine historical demographic trends for six species of milksnake with representatives in both the temperate and tropical Americas to determine if species share responses to climate change as a taxon or by area (i.e., temperate versus tropical environments). Using a multilocus dataset, we test for the demographic signature of population expansion and decline using non-genealogical summary statistics, as well as coalescent-based methods. In addition, we determine whether range sizes are correlated with effective population sizes for milksnakes. Results indicate that there are no identifiable trends with respect to demographic response based on location, and that species responded to changing climates independently, with tropical taxa showing greater instability. There is also no correlation between range size and effective population size, with the largest population size belonging to the species with the smallest geographic distribution. Our study highlights the importance of not generalizing the demographic histories of taxa by region and further illustrates that the New World tropics may not have been a stable refuge during the Pleistocene. PMID:26083467

  13. Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific

    PubMed Central

    Groom, Scott V. C.; Stevens, Mark I.; Schwarz, Michael P.

    2014-01-01

    The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops. PMID:24807250

  14. Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific.

    PubMed

    Groom, Scott V C; Stevens, Mark I; Schwarz, Michael P

    2014-06-22

    The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops. PMID:24807250

  15. Lifestyle and Ice: The Relationship between Ecological Specialization and Response to Pleistocene Climate Change.

    PubMed

    Kašparová, Eva; Van de Putte, Anton P; Marshall, Craig; Janko, Karel

    2015-01-01

    Major climatic changes in the Pleistocene had significant effects on marine organisms and the environments in which they lived. The presence of divergent patterns of demographic history even among phylogenetically closely-related species sharing climatic changes raises questions as to the respective influence of species-specific traits on population structure. In this work we tested whether the lifestyle of Antarctic notothenioid benthic and pelagic fish species from the Southern Ocean influenced the concerted population response to Pleistocene climatic fluctuations. This was done by a comparative analysis of sequence variation at the cyt b and S7 loci in nine newly sequenced and four re-analysed species. We found that all species underwent more or less intensive changes in population size but we also found consistent differences between demographic histories of pelagic and benthic species. Contemporary pelagic populations are significantly more genetically diverse and bear traces of older demographic expansions than less diverse benthic species that show evidence of more recent population expansions. Our findings suggest that the lifestyles of different species have strong influences on their responses to the same environmental events. Our data, in conjunction with previous studies showing a constant diversification tempo of these species during the Pleistocene, support the hypothesis that Pleistocene glaciations had a smaller effect on pelagic species than on benthic species whose survival may have relied upon ephemeral refugia in shallow shelf waters. These findings suggest that the interaction between lifestyle and environmental changes should be considered in genetic analyses. PMID:26535569

  16. Size matters: plasticity in metabolic scaling shows body-size may modulate responses to climate change.

    PubMed

    Carey, Nicholas; Sigwart, Julia D

    2014-08-01

    Variability in metabolic scaling in animals, the relationship between metabolic rate ( R: ) and body mass ( M: ), has been a source of debate and controversy for decades. R: is proportional to MB: , the precise value of B: much debated, but historically considered equal in all organisms. Recent metabolic theory, however, predicts B: to vary among species with ecology and metabolic level, and may also vary within species under different abiotic conditions. Under climate change, most species will experience increased temperatures, and marine organisms will experience the additional stressor of decreased seawater pH ('ocean acidification'). Responses to these environmental changes are modulated by myriad species-specific factors. Body-size is a fundamental biological parameter, but its modulating role is relatively unexplored. Here, we show that changes to metabolic scaling reveal asymmetric responses to stressors across body-size ranges; B: is systematically decreased under increasing temperature in three grazing molluscs, indicating smaller individuals were more responsive to warming. Larger individuals were, however, more responsive to reduced seawater pH in low temperatures. These alterations to the allometry of metabolism highlight abiotic control of metabolic scaling, and indicate that responses to climate warming and ocean acidification may be modulated by body-size. PMID:25122741

  17. Connecting differential responses of native and invasive riparian plants to climate change and environmental alteration.

    PubMed

    Flanagan, Neal E; Richardson, Curtis J; Ho, Mengchi

    2015-04-01

    Climate change is predicted to impact river systems in the southeastern United States through alterations of temperature, patterns of precipitation and hydrology. Future climate scenarios for the southeastern United States predict (1) surface water temperatures will warm in concert with air temperature, (2) storm flows will increase and base flows will decrease, and (3) the annual pattern of synchronization between hydroperiod and water temperature will be altered. These alterations are expected to disturb floodplain plant communities, making them more vulnerable to establishment of invasive species. The primary objective of this study is to evaluate whether native and invasive riparian plant assemblages respond differently to alterations of climate and land use. To study the response of riparian wetlands to watershed and climate alterations, we utilized an existing natural experiment imbedded in gradients of temperature and hydrology-found among dammed and undammed rivers. We evaluated a suite of environmental variables related to water temperature, hydrology, watershed disturbance, and edaphic conditions to identify the strongest predictors of native and invasive species abundances. We found that native species abundance is strongly influenced by climate-driven variables such as temperature and hydrology, while invasive species abundance is more strongly influenced by site-specific factors such as land use and soil nutrient availability. The patterns of synchronization between plant phenology, annual hydrographs, and annual water temperature cycles may be key factors sustaining the viability of native riparian plant communities. Our results demonstrate the need to understand the interactions between climate, land use, and nutrient management in maintaining the species diversity of riparian plant communities. Future climate change is likely to result in diminished competitiveness of native plant species, while the competitiveness of invasive species will increase

  18. Evolutionary response of landraces to climate change in centers of crop diversity

    PubMed Central

    Mercer, Kristin L; Perales, Hugo R

    2010-01-01

    Landraces cultivated in centers of crop diversity result from past and contemporary patterns of natural and farmer-mediated evolutionary forces. Successful in situ conservation of crop genetic resources depends on continuity of these evolutionary processes. Climate change is projected to affect agricultural production, yet analyses of impacts on in situ conservation of crop genetic diversity and farmers who conserve it have been absent. How will crop landraces respond to alterations in climate? We review the roles that phenotypic plasticity, evolution, and gene flow might play in sustaining production, although we might expect erosion of genetic diversity if landrace populations or entire races lose productivity. For example, highland maize landraces in southern Mexico do not express the plasticity necessary to sustain productivity under climate change, but may evolve in response to altered conditions. The outcome for any given crop in a given region will depend on the distribution of genetic variation that affects fitness and patterns of climate change. Understanding patterns of neutral and adaptive diversity from the population to the landscape scale is essential to clarify how landraces conserved in situ will continue to evolve and how to minimize genetic erosion of this essential natural resource. PMID:25567941

  19. Evolutionary response of landraces to climate change in centers of crop diversity.

    PubMed

    Mercer, Kristin L; Perales, Hugo R

    2010-09-01

    Landraces cultivated in centers of crop diversity result from past and contemporary patterns of natural and farmer-mediated evolutionary forces. Successful in situ conservation of crop genetic resources depends on continuity of these evolutionary processes. Climate change is projected to affect agricultural production, yet analyses of impacts on in situ conservation of crop genetic diversity and farmers who conserve it have been absent. How will crop landraces respond to alterations in climate? We review the roles that phenotypic plasticity, evolution, and gene flow might play in sustaining production, although we might expect erosion of genetic diversity if landrace populations or entire races lose productivity. For example, highland maize landraces in southern Mexico do not express the plasticity necessary to sustain productivity under climate change, but may evolve in response to altered conditions. The outcome for any given crop in a given region will depend on the distribution of genetic variation that affects fitness and patterns of climate change. Understanding patterns of neutral and adaptive diversity from the population to the landscape scale is essential to clarify how landraces conserved in situ will continue to evolve and how to minimize genetic erosion of this essential natural resource. PMID:25567941

  20. Simulating the vegetation response in western Europe to abrupt climate changes under glacial background conditions

    NASA Astrophysics Data System (ADS)

    Woillez, M.-N.; Kageyama, M.; Combourieu-Nebout, N.; Krinner, G.

    2013-03-01

    The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard-Oeschger (DO) and Heinrich (HE) events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC) and led to major changes in the terrestrial biosphere. Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. We force ORCHIDEE offline with outputs from the IPSL_CM4 general circulation model, in which the AMOC is forced to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available for comparison. The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to a hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO. For both a collapse or a recovery of the AMOC, the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  1. Changing climatic response: a conceptual model for glacial cycles and the Mid-Pleistocene Transition

    NASA Astrophysics Data System (ADS)

    Daruka, I.; Ditlevsen, P. D.

    2014-03-01

    Milankovitch's astronomical theory of glacial cycles, attributing ice age climate oscillations to orbital changes in Northern Northern-Hemisphere insolation, is challenged by the paleoclimatic record. The climatic response to the variations in insolation is far from trivial. In general the glacial cycles are highly asymmetric in time, with slow cooling from the interglacials to the glacials (inceptions) and very rapid warming from the glacials to the interglacials (terminations). We shall refer to this fast-slow dynamics as the "saw-tooth" shape of the paleoclimatic record. This is non-linearly related to the time-symmetric variations in the orbital forcing. However, the most pronounced challenge to the Milankovitch theory is the Mid-Pleistocene Transition (MPT) occurring about one million years ago. During that event, the prevailing 41 kyr glacial cycles, corresponding to the almost harmonic obliquity cycle were replaced by longer saw-tooth shaped cycles with a time scale around 100 kyr. The MPT must have been driven by internal changes in climate response, since it does not correspond to any apparent changes in the orbital forcing. In order to identify possible mechanisms causing the observed changes in glacial dynamics, it is relevant to study simplified models with the capability of generating temporal behavior similar to the observed records. We present a simple oscillator type model approach, with two variables, a temperature anomaly and an ice volume analogous, climatic memory term. The generalization of the ice albedo feedback is included in terms of an effective multiplicative coupling between this latter climatic memory term (representing the internal degrees of freedom) and the external drive. The simple model reproduces the temporal asymmetry of the late Pleistocene glacial cycles and suggests that the MPT can be explained as a regime shift, aided by climatic noise, from a period 1 frequency locking to the obliquity cycle to a period 2-3 frequency

  2. On the brink of change: plant responses to climate on the Colorado Plateau

    USGS Publications Warehouse

    Munson, Seth M.; Belnap, Jayne; Schelz, Charles D.; Moran, Mary; Carolin, Tara W.

    2011-01-01

    The intensification of aridity due to anthropogenic climate change in the southwestern U.S. is likely to have a large impact on the growth and survival of plant species that may already be vulnerable to water stress. To make accurate predictions of plant responses to climate change, it is essential to determine the long-term dynamics of plant species associated with past climate conditions. Here we show how the plant species and functional types across a wide range of environmental conditions in Colorado Plateau national parks have changed with climate variability over the last twenty years. During this time, regional mean annual temperature increased by 0.18°C per year from 1989–1995, 0.06°C per year from 1995–2003, declined by 0.14°C from 2003–2008, and there was high interannual variability in precipitation. Non-metric multidimensional scaling of plant species at long-term monitoring sites indicated five distinct plant communities. In many of the communities, canopy cover of perennial plants was sensitive to mean annual temperature occurring in the previous year, whereas canopy cover of annual plants responded to cool season precipitation. In the perennial grasslands, there was an overall decline of C3 perennial grasses, no change of C4 perennial grasses, and an increase of shrubs with increasing temperature. In the shrublands, shrubs generally showed no change or slightly increased with increasing temperature. However, certain shrub species declined where soil and physical characteristics of a site limited water availability. In the higher elevation woodlands, Juniperus osteosperma and shrub canopy cover increased with increasing temperature, while Pinus edulis at the highest elevation sites was unresponsive to interannual temperature variability. These results from well-protected national parks highlight the importance of temperature to plant responses in a water-limited region and suggest that projected increases in aridity are likely to promote

  3. Role of Soils in Hydrologic Response to Climate Extremes and Land Use Change

    NASA Astrophysics Data System (ADS)

    Scanlon, B. R.; Zhang, Z.; Save, H.; Reedy, R. C.; Faunt, C. C.

    2015-12-01

    Increasing demand for water in response to growing global population underscores the need to better understand linkages and feedbacks between land surface processes and water resources to manage water resources more sustainably. Here we examine the role of soils on hydrologic response to climate extremes and land use change using field scale and remote sensing data at point to basin scales in the U.S. High Plains and California Central Valley. In the U.S. High Plains, soil-textural variations make the difference between sustainable water resources related to coarse-grained soils in the northern High Plains and groundwater mining associated with fine-grained soils in much of the central and southern High Plains. Field data show dynamic response of water resources to droughts and land use change in the northern High Plains with limited response in much of the central and southern High Plains. Soil profiles provide a key to the past by archiving system response to environmental changes in subsurface soil physics and environmental tracer data. Areas with coarse-grained soils are vulnerable to reduced recharge during droughts and increased recharge with land use change from perennial to annual vegetation whereas fine-grained soils are generally insensitive to these stresses. GRACE satellite monitoring of total water storage variations in response to recent droughts is consistent with these spatial variations in soils across the High Plains and hydrologic response to droughts.In the California Central Valley, coarse grained soils in alluvial basins result in dynamic hydrologic responses to climate extremes. GRACE satellite data show marked depletion in total water storage in response to recent droughts reflecting groundwater and surface reservoir storage declines consistent with regional groundwater modeling and monitoring data. The coarse alluvial soils typical of much of the region facilitate managed aquifer recharge in depleted aquifers to complement surface reservoir

  4. Assessing Land Management Changes and Population Dynamics in Central Burkina Faso in Response to Climate Change.

    NASA Astrophysics Data System (ADS)

    Kabore Bontogho, P. E.; Boubacar, I.; Afouda, A.; Joerg, H.

    2015-12-01

    Assessing landscape and population's dynamics at watershed level contribute to address anthropogenic aspect of climate change issue owing to the close link between LULC and climate changes. The objective of this study is to explore the dependencies of population to land management changes in Massili basin (2612 km²) located in central Burkina Faso. A set of three satellite scenes was acquired for the years 1990 (Landsat 7 ETM), 2002 (Landsat 7 ETM+) and 2013 (Landsat 8 OLI/TIRS) from the Global Land Cover Facility's (GLCF) website. Census data were provided by the National institute of statistics and demographic (INSD). The satellites images were classified using object-oriented classification method which was supported by historic maps and field data. Those were collected in order to allow for class definition, verification and accuracy assessments. Based on the developed land use maps, change analysis was carried out using post classification comparison in GIS. Finally, derived land use changes were compared with census data in order to explore links between population dynamics and the land use changes. It was found in 1990 that Massili watershed LULC was dominated by Tree/shrub savannah (69%, 1802.28 km2 ), Farm/Fallow was representing 22%, Gallery forest (4%), Settlement (3%), Barre soil (1%), Water bodies (1%). In 2002, the major landscape was Farm (54%). Tree/Shrub savannas were reduced to 36% while the Gallery Forest was decreased to1% of the basin area. The situation has also slightly changed in 2013 with an increase of the area devoted to farm/fallow and settlement at a rate of 3% and Gallery forest has increased to 4%. The changes in land use are in agreement with a notable increase in population. The analysis of census data showed that the number of inhabitants increased from 338 inhabitants per km2 in 1990 to 1150 inhabitants per km2 in 2013. As shown by statistical analysis (Kendall correlation tau=0.9), there is a close relation between both dynamics.

  5. Modeling the biogeomorphic evolution of coastal dunes in response to climate change

    NASA Astrophysics Data System (ADS)

    Keijsers, J. G. S.; De Groot, A. V.; Riksen, M. J. P. M.

    2016-06-01

    Coastal dunes form in many parts of the world the first flood defense line against the sea. To study effects of climate change on coastal dune evolution, we used a cellular model of dune, beach, and vegetation development. The model was calibrated and validated against field measurements of the Dutch coast, showing good performance for 10 year simulations. A sensitivity analysis showed that dune size and morphology are most sensitive to the rate of aeolian input and wave dissipation. Finally, 100 year climate change scenarios were run to establish the impacts of sea level rise and changes in vegetation growth rate on dune evolution. The results are in good agreement with conceptual models of dune evolution. Sea level rise largely determines the direction of dune evolution: the rate of rising controls whether dunes are able to preserve their height or sand volume while migrating landward. The effect of changing vegetation growth rates, resulting from climate change, is most manifest in dune response to large disturbances. If vegetation is removed halfway into the simulation, vegetation growth rate determines whether a foredune will revegetate and recover its height. Low vegetation growth rates result in mobile dunes that lose sand. The good agreement between observations and predictions indicates that the model successfully incorporates the suite of biogeomorphic and marine processes involved in dune building.

  6. Changes in land surface albedo in response of climate change and human activities

    NASA Astrophysics Data System (ADS)

    Liang, S.

    2013-05-01

    Our Earth's environment is experiencing rapid changes due to natural variability and human activities. Albedo is an important indicator of the changes in land surface properties. This presentation will consist of two parts. The first part is on our efforts for generating global long-term high-quality land surface albedo products. In the past few years, we have been actively working on estimation of land surface albedo from multiple satellite data, such as AVHRR, MODIS, and VIIRS. One of our key products is the Global Land Surface Satellite (GLASS) albedo product from both AVHRR (1981-1999) and MODIS (2000-2010) data at 1-5km spatial and 8-day temporal resolutions. The projects, algorithm development, and product validation would be outlined. The second part will be on spatiotemporal analysis of global albedo changes and their attributions. The emphasis will be on the regional "hotspots", such as Greenland, Tibetan plateau, and northern China where albedo changes are associated with climate change, drought, forest fires, reforestation and afforestation, and agricultural irrigation.

  7. Modelling the response of fresh groundwater to climate and vegetation changes in coral islands

    NASA Astrophysics Data System (ADS)

    Comte, Jean-Christophe; Join, Jean-Lambert; Banton, Olivier; Nicolini, Eric

    2014-12-01

    In coral islands, groundwater is a crucial freshwater resource for terrestrial life, including human water supply. Response of the freshwater lens to expected climate changes and subsequent vegetation alterations is quantified for Grande Glorieuse, a low-lying coral island in the Western Indian Ocean. Distributed models of recharge, evapotranspiration and saltwater phytotoxicity are integrated into a variable-density groundwater model to simulate the evolution of groundwater salinity. Model results are assessed against field observations including groundwater and geophysical measurements. Simulations show the major control currently exerted by the vegetation with regards to the lens morphology and the high sensitivity of the lens to climate alterations, impacting both quantity and salinity. Long-term changes in mean sea level and climatic conditions (rainfall and evapotranspiration) are predicted to be responsible for an average increase in salinity approaching 140 % (+8 kg m-3) when combined. In low-lying areas with high vegetation density, these changes top +300 % (+10 kg m-3). However, due to salinity increase and its phytotoxicity, it is shown that a corollary drop in vegetation activity can buffer the alteration of fresh groundwater. This illustrates the importance of accounting for vegetation dynamics to study groundwater in coral islands.

  8. Simulated Vegetation Response to Climate Change in California: The Importance of Seasonal Production Patterns

    NASA Astrophysics Data System (ADS)

    Kim, J. B.; Pitts, B.

    2013-12-01

    MC1 dynamic global vegetation model simulates vegetation response to climate change by simulating vegetation production, soil biogeochemistry, plant biogeography and fire. It has been applied at a wide range of spatial scales, yet the spatio-temporal patterns of simulated vegetation production, which drives the model's response to climate change, has not been examined in detail. We ran MC1 for California at a relatively fine scale, 30 arc-seconds, for the historical period (1895-2006) and for the future (2007-2100), using downscaled data from four CMIP3-based climate projections: A2 and B1 GHG emissions scenarios simulated by PCM and GFDL GCMs. The use of these four climate projections aligns our work with a body of climate change research work commissioned by the California Public Interest Energy Research (PIER) Program. The four climate projections vary not only in terms of changes in their annual means, but in the seasonality of projected climate change. We calibrated MC1 using MODIS NPP data for 2000-2011 as a guide, and adapting a published technique for adjusting simulated vegetation production by increasing the simulated plant rooting depths. We evaluated the simulation results by comparing the model output for the historical period with several benchmark datasets, summarizing by EPA Level 3 Ecoregions. Multi-year summary statistics of model predictions compare moderately well with Kuchler's potential natural vegetation map, National Biomass and Carbon Dataset, Leenhouts' compilation of fire return intervals, and, of course, the MODIS NPP data for 2000-2011. When we compared MC1's monthly NPP values with MODIS monthly GPP data (2000-2011), however, the seasonal patterns compared very poorly, with NPP/GPP ratio for spring (Mar-Apr-May) often exceeding 1, and the NPP/GPP ratio for summer (Jun-Jul-Aug) often flattening to zero. This suggests MC1's vegetation production algorithms are overly biased for spring production at the cost of summer production. We

  9. Modelling climate change responses in tropical forests: similar productivity estimates across five models, but different mechanisms and responses

    NASA Astrophysics Data System (ADS)

    Rowland, L.; Harper, A.; Christoffersen, B. O.; Galbraith, D. R.; Imbuzeiro, H. M. A.; Powell, T. L.; Doughty, C.; Levine, N. M.; Malhi, Y.; Saleska, S. R.; Moorcroft, P. R.; Meir, P.; Williams, M.

    2015-04-01

    Accurately predicting the response of Amazonia to climate change is important for predicting climate change across the globe. Changes in multiple climatic factors simultaneously result in complex non-linear ecosystem responses, which are difficult to predict using vegetation models. Using leaf- and canopy-scale observations, this study evaluated the capability of five vegetation models (Community Land Model version 3.5 coupled to the Dynamic Global Vegetation model - CLM3.5-DGVM; Ecosystem Demography model version 2 - ED2; the Joint UK Land Environment Simulator version 2.1 - JULES; Simple Biosphere model version 3 - SiB3; and the soil-plant-atmosphere model - SPA) to simulate the responses of leaf- and canopy-scale productivity to changes in temperature and drought in an Amazonian forest. The models did not agree as to whether gross primary productivity (GPP) was more sensitive to changes in temperature or precipitation, but all the models were consistent with the prediction that GPP would be higher if tropical forests were 5 °C cooler than current ambient temperatures. There was greater model-data consistency in the response of net ecosystem exchange (NEE) to changes in temperature than in the response to temperature by net photosynthesis (An), stomatal conductance (gs) and leaf area index (LAI). Modelled canopy-scale fluxes are calculated by scaling leaf-scale fluxes using LAI. At the leaf-scale, the models did not agree on the temperature or magnitude of the optimum points of An, Vcmax or gs, and model variation in these parameters was compensated for by variations in the absolute magnitude of simulated LAI and how it altered with temperature. Across the models, there was, however, consistency in two leaf-scale responses: (1) change in An with temperature was more closely linked to stomatal behaviour than biochemical processes; and (2) intrinsic water use efficiency (IWUE) increased with temperature, especially when combined with drought. These results suggest

  10. The change of global terrestrial ecosystem net primary productivity (NPP) and its response to climate change in CMIP5

    NASA Astrophysics Data System (ADS)

    Li, Suosuo; Lü, Shihua; Zhang, Yongjun; Liu, Yuanpu; Gao, Yanhong; Ao, Yinhuan

    2015-07-01

    Using global terrestrial ecosystem observation and proxy data for net primary productivity (NPP), leaf area index (LAI), and climate data, we compared simulated NPP, LAI, and major climatic factors and explored the relationship between their variations in historical scenarios of ten Coupled Model Intercomparison Project (CMIP5) models. The results showed that global spatial patterns of the simulated terrestrial ecosystem and climate are consistent with proxy data, but the values have some differences for each model. Based on statistical analysis, the simulated climatic factors were found to be better than terrestrial ecosystem NPP and LAI, and the multi-model ensemble (MME) results were better than every single model. For the terrestrial ecosystem, air temperature (Ta) was found to be the major affecting factor, followed by precipitation, meaning the terrestrial ecosystem NPP and LAI are more related to Ta than precipitation. Meanwhile, surface downwelling shortwave radiation (Rsds) was found to inhibit the terrestrial ecosystem in almost all regions of the world. Between 1976 and 2005, precipitation had a slight increasing trend, Ta an obvious increasing trend, and Rsds a slight decreasing trend. The changes of precipitation, air temperature, and Rsds were favorable for the terrestrial ecosystem and for plant growth. Therefore, LAI and NPP showed an obvious increasing temporal trend, and the terrestrial ecosystem showed a positive response to climate change. All the model results showed NPP had an increasing temporal trend in the past 150 years, which also indicated that the terrestrial ecosystem has shown a positive response to climate change in that time period. In terms of the global average, the simulated NPP varied from 21.5 to 69.3 Pg C year-1, and the MME NPP is about 50.6, which was almost consistent with the International Geosphere Biosphere Program (IGBP) NPP result of 55.1 and Moderate Resolution Imaging Spectroradiometer (MODIS) NPP results of 60.5 Pg

  11. Differential Responses of Neotropical Mountain Forests to Climate Change during the Last Millenium

    NASA Astrophysics Data System (ADS)

    Figueroa-Rangel, B. L.; Olvera Vargas, M.

    2013-05-01

    The long-term perspective in the conservation of mountain ecosystems using palaeoecological and paleoclimatological techniques are providing with crucial information for the understanding of the temporal range and variability of ecological pattern and processes. This perception is contributing with means to anticipate future conditions of these ecosystems, especially their response to climate change. Neotropical mountain forests, created by a particular geological and climatic history in the Americas, represent one of the most distinctive ecosystems in the tropics which are constantly subject to disturbances included climate change. Mexico due to its geographical location between the convergence of temperate and tropical elements, its diverse physiography and climatic heterogeneity, contains neotropical ecosystems with high biodiversity and endemicity whose structure and taxonomical composition have changed along centurial to millennial scales. Different neotropical forests expand along the mountain chains of Mexico with particular responses along spatial and temporal scales. Therefore in order to capture these scales at fine resolution, sedimentary sequences from forest hollows were retrieved from three forest at different altitudes within 10 km; Pine forest (PF), Transitional forest (TF) and Cloud forest (CF). Ordination techniques were used to relate changes in vegetation with the environment every ~60 years. The three forests experience the effect of the dry stage ~AD 800-1200 related to the Medieval Warm Period reported for several regions of the world. CF contracted, PF expanded while the TF evolved from CF to a community dominated by dry-resistant epiphytes. Dry periods in PF and TF overlapped with the increase in fire occurrences while a dissimilar pattern took place in CF. Maize, Asteraceae and Poaceae were higher during dry intervals while epiphytes decreased. A humid period ~1200-1450 AD was associated with an expansion and a high taxa turnover in CF

  12. Detecting mismatches of bird migration stopover and tree phenology in response to changing climate

    USGS Publications Warehouse

    Kellermann, Jherime L.; Van Riper, Charles, III

    2015-01-01

    Migratory birds exploit seasonal variation in resources across latitudes, timing migration to coincide with the phenology of food at stopover sites. Differential responses to climate in phenology across trophic levels can result in phenological mismatch; however, detecting mismatch is sensitive to methodology. We examined patterns of migrant abundance and tree flowering, phenological mismatch, and the influence of climate during spring migration from 2009 to 2011 across five habitat types of the Madrean Sky Islands in southeastern Arizona, USA. We used two metrics to assess phenological mismatch: synchrony and overlap. We also examined whether phenological overlap declined with increasing difference in mean event date of phenophases. Migrant abundance and tree flowering generally increased with minimum spring temperature but depended on annual climate by habitat interactions. Migrant abundance was lowest and flowering was highest under cold, snowy conditions in high elevation montane conifer habitat while bird abundance was greatest and flowering was lowest in low elevation riparian habitat under the driest conditions. Phenological synchrony and overlap were unique and complementary metrics and should both be used when assessing mismatch. Overlap declined due to asynchronous phenologies but also due to reduced migrant abundance or flowering when synchrony was actually maintained. Overlap declined with increasing difference in event date and this trend was strongest in riparian areas. Montane habitat specialists may be at greatest risk of mismatch while riparian habitat could provide refugia during dry years for phenotypically plastic species. Interannual climate patterns that we observed match climate change projections for the arid southwest, altering stopover habitat condition.

  13. Plant Functional Variability in Response to Late-Quaternary Climate Change Recorded in Ancient Packrat Middens

    NASA Astrophysics Data System (ADS)

    Holmgren, C. A.; Potts, D. L.

    2006-12-01

    Responses of plant functional traits to environmental variability are of enduring interest because they constrain organism performance and ecosystem function. However, most inferences regarding plant functional trait response to climatic variability have been limited to the modern period. To better understand plant functional response to long-term climate variability and how adjustments in leaf morphology may contribute to patterns of species establishment, persistence, or extirpation, we measured specific leaf area (SLA) from macrofossils preserved in ancient packrat middens collected along the Arizona/New Mexico border, USA. Our record spanned more than 32,000 years and included six woodland and Chihuahuan Desert species: Berberis cf. haematocarpa, Juniperus cf. coahuilensis, Juniperus osteosperma, Larrea tridentata, Prosopis glandulosa and Parthenium incanum. We predicted that regional climatic warming and drying since the late Pleistocene would result in intraspecific decreases in SLA. As predicted, SLA was positively correlated with midden age for three of the six species (L. tridentata, J. osteosperma, B. cf. haematocarpa). SLA was also negatively correlated with December (L. tridentata, J. cf. coahuilensis) or June (B. cf. haematocarpa, J. osteosperma) insolation. A unique record of vegetation community dynamics, plant macrofossils preserved in packrat middens also represent a rich and largely untapped source of information on long-term trends in species functional response to environmental change.

  14. Climate change and disaster management.

    PubMed

    O'Brien, Geoff; O'Keefe, Phil; Rose, Joanne; Wisner, Ben

    2006-03-01

    Climate change, although a natural phenomenon, is accelerated by human activities. Disaster policy response to climate change is dependent on a number of factors, such as readiness to accept the reality of climate change, institutions and capacity, as well as willingness to embed climate change risk assessment and management in development strategies. These conditions do not yet exist universally. A focus that neglects to enhance capacity-building and resilience as a prerequisite for managing climate change risks will, in all likelihood, do little to reduce vulnerability to those risks. Reducing vulnerability is a key aspect of reducing climate change risk. To do so requires a new approach to climate change risk and a change in institutional structures and relationships. A focus on development that neglects to enhance governance and resilience as a prerequisite for managing climate change risks will, in all likelihood, do little to reduce vulnerability to those risks. PMID:16512862

  15. Potential changes in slab avalanche activity in Colorado in response to climate change

    NASA Astrophysics Data System (ADS)

    Wagner, R.; Barlow, N.; Smith, A.

    2013-12-01

    The development of slab avalanches is a complex interaction between terrain, meteorological forcing, and snowpack microphysical processes. The magnitude, frequency, and seasonal timing of avalanches are likely to be influenced by climate change over the next century. Here we present spatial and seasonal variability in meteorological forcing of slab avalanches in several mountain ranges in Colorado, and changes in avalanche activity simulated using enhanced GHG concentrations. In particular, the study identifies loading factors (new snow, snow density, wind) and the development of weak layers using observed and modeled inputs. For the development of weak layers (especially depth hoar), the study will assess early season periods of cold temperatures and shallow snowpack, and also utilizes the SNOWPACK model, whose inputs are surface temperature and humidity, accumulated snow, wind, and surface radiation terms. Results using observed data are compared to those from model output from NCAR's Colorado Headwaters project, which coupled a high-resolution WRF model with the NOAH surface model. Changes in enhanced GHG simulations of the WRF model reveal potential changes in avalanche hazard, including differences in the seasonal cycle.

  16. Estimating the regional climate responses over river basins to changes in tropical sea surface temperature patterns

    NASA Astrophysics Data System (ADS)

    Tsai, Chii-Yun; Forest, Chris E.; Wagener, Thorsten

    2015-10-01

    We investigate how to identify and assess teleconnection signals between anomalous patterns of sea surface temperature (SST) changes and climate variables related to hydrologic impacts over different river basins. The regional climate sensitivity to tropical SST anomaly patterns is examined through a linear relationship given by the global teleconnection operator (GTO, also generally called a sensitivity matrix or an empirical Green's function). We assume that the GTO defines a multilinear relation between SST forcing and regional climate response of a target area. The sensitivities are computed based on data from a large ensemble of simulations using the NCAR Community Atmospheric Model version 3.1 (CAM 3.1). The linear approximation is evaluated by comparing the linearly reconstructed response with both the results from the full non-linear atmospheric model and observational data. The results show that the linear approximation can capture regional climate variability that the CAM 3.1 AMIP-style simulations produce at seasonal scales for multiple river basins. The linear method can be used potentially for estimating drought conditions, river flow forecasting, and agricultural water management problems.

  17. Water yield responses to high and low spatial resolution climate change scenarios in the Missouri River Basin

    NASA Astrophysics Data System (ADS)

    Stone, Mark C.; Hotchkiss, Rollin H.; Mearns, Linda O.

    2003-02-01

    Water yield responses to two climate change scenarios of different spatial scales were compared for the Missouri River Basin. A coarse-resolution climate change scenario was created from runs of the Commonwealth Scientific and Industrial Research Organization General Circulation Model (CSIRO GCM). The high-resolution climate change scenario was developed using runs of the Regional Climate Model RegCM, for which the GCM provided the initial and lateral boundary conditions. Water yield responses to the high- and low-resolution climate change scenarios were investigated using the Soil and Water Assessment Tool (SWAT). Basin-wide water yield increased for both GCM and RegCM scenarios but with an overall greater increase for the RegCM scenario. Significant differences in water yields were found between the GCM and RegCM climate scenarios.

  18. Delayed Response of Lake Area Change to Climate Change in Siling Co Lake, Tibetan Plateau, from 2003 to 2013.

    PubMed

    Yi, Guihua; Zhang, Tingbin

    2015-11-01

    The Tibetan Plateau is a key area for research on global environmental changes. During the past 50 years, the climate in the Siling Co lake area has become continuously warmer and wetter, which may have further caused the increase in Siling Co lake area. Based on the Siling Co lake area (2003 to 2013) and climate data acquired from the Xainza and Baingoin meteorological stations (covering 1966 to 2013), we analyzed the delayed responses of lake area changes to climate changes through grey relational analysis. The following results were obtained: (1) The Siling Co lake area exhibited a rapid expansion trend from 2003 to 2013. The lake area increased to 2318 km², with a growth ratio of 14.6% and an annual growth rate of 26.84 km²·year(-1); (2) The rate of air temperature increase was different in the different seasons. The rate in the cold season was about 0.41 °C per ten years and 0.32 °C in hot season. Precipitation evidently increased, with a change rate of 17.70 mm per ten years in the hot season and a slight increase with a change rate of 2.36 mm per ten years in the cold season. Pan evaporation exhibited evidently decreasing trends in both the hot and cold seasons, with rates of -33.35 and -14.84 mm per ten years, respectively; (3) An evident delayed response of lake area change to climate change is observed, with a delay time of approximately one to two years. PMID:26528996

  19. Delayed Response of Lake Area Change to Climate Change in Siling Co Lake, Tibetan Plateau, from 2003 to 2013

    PubMed Central

    Yi, Guihua; Zhang, Tingbin

    2015-01-01

    The Tibetan Plateau is a key area for research on global environmental changes. During the past 50 years, the climate in the Siling Co lake area has become continuously warmer and wetter, which may have further caused the increase in Siling Co lake area. Based on the Siling Co lake area (2003 to 2013) and climate data acquired from the Xainza and Baingoin meteorological stations (covering 1966 to 2013), we analyzed the delayed responses of lake area changes to climate changes through grey relational analysis. The following results were obtained: (1) The Siling Co lake area exhibited a rapid expansion trend from 2003 to 2013. The lake area increased to 2318 km2, with a growth ratio of 14.6% and an annual growth rate of 26.84 km2·year−1; (2) The rate of air temperature increase was different in the different seasons. The rate in the cold season was about 0.41 °C per ten years and 0.32 °C in hot season. Precipitation evidently increased, with a change rate of 17.70 mm per ten years in the hot season and a slight increase with a change rate of 2.36 mm per ten years in the cold season. Pan evaporation exhibited evidently decreasing trends in both the hot and cold seasons, with rates of −33.35 and −14.84 mm per ten years, respectively; (3) An evident delayed response of lake area change to climate change is observed, with a delay time of approximately one to two years. PMID:26528996

  20. Tree Growth Responses to Climate Change at the Upper Treeline in the Mountains of Western Tuva

    NASA Astrophysics Data System (ADS)

    Kolunchukova, Mariam; Reznikov, Andrey; Chistyakov, Kirill

    2015-04-01

    The response of forest to climate change is most pronounced at higher elevations due to the limitation of growth by temperature and precipitation. Modern instrumental measurements show temperature increase during the 20th century that causes rising of upper boundary of forests in the mountain regions. Climate-driven upward tree migration in the region of Altai-Sayan Mountains has been demonstrated in a number of investigations. The purpose of this research was an analysis of the impact of main climatic factors on tree growth and current treeline dynamics under the climate changes in the mountains of Western Tuva. Tree-ring width chronologies were built based on larch samples (Larix sibirica) of living trees from the upper treeline, the chronologies were compared, their statistics were estimated, and correlation with temperatures and precipitations were analyzed. Tree growth is dominated by two major factors - moisture supply and summer temperatures. It is generally hypothesized that tree growth at the lower treeline is precipitation limited while at the upper treeline is normally controlled by temperature. However in the upper forest belt temperature can influence tree growth negatively as well as positively. Correlations between chronologies and climatic factors revealed different climatic influences on radial growth along a north-south gradient in the study area. Within northern wetter areas tree ring width correlates positively with summer temperatures and negatively with precipitation, so temperature increase leads to rise of upper treeline. Within southern drier areas tree ring width correlates positively with precipitation and negatively with rising summer temperatures. The analysis showed that in this case the tree growth is determined by combination of optimal temperature and maximum precipitation. The results provide evidence of critical importance of temperature and precipitation in the upper forest belt and will be used in subsequent analysis of temporal

  1. Methane pools within the Glacial Lake Agassiz Peatlands (GLAP) and their response to climatic change.

    NASA Astrophysics Data System (ADS)

    Glaser, P. H.; Chanton, J.; Siegel, D. I.; Reeve, A. S.; Corbett, J. E.; Rosenberry, D. O.

    2014-12-01

    Global warming may destabilize the carbon pool in northern peatlands but it remains uncertain how climatic patterns regulate the transformation of solid-phase peat into greenhouse gases. Here we present a 43-year record of changes in the pore water chemistry from a major peat basin in northern Minnesota. These data indicate that methane production and its transient storage within bogs and fens is finely tuned to climatically driven flow systems on multiple time scales. The peak zones for methanogenesis were apparently limited to the uppermost peat strata during a dry climatic period (1965-1983) when shallow recharge systems prevailed across the GLAP. The shift to a moister climate after 1990 strengthened downward transport systems across the region greatly expanding the vertical suppy of labile root exudates and the peak production zones for methanogenesis in peat profiles. Large methane pools accumulated within the GLAP from 1990 through 2008. Dissolved methane concentrations were 2-to-4 times greater within the deeper peat (1-4 m) than above and were generally higher within bog landforms than in sedge fens. The size of these methane pools varied in response to seasonal and interannual climatic oscillations that apparently affected emission rates via ebullition (from deep peat) and wicking through plant stoma (from the rhizosphere). However, methane pools remained relatively stable during this period, except for a large change between 1990 and 1991. One remaining element of uncertainty concerns the transformation of dissolved methane to free-phase bubbles, which can represent 10-20% of peat volume in the GLAP. Nevertheless, methane profiles from the GLAP indicate that the entire peat profile can function as an incubator for methane depending on the prevailing climate regime and downward transport of labile carbon substrates.

  2. Multiple phenological responses to climate change among 42 plant species in Xi'an, China

    NASA Astrophysics Data System (ADS)

    Dai, Junhu; Wang, Huanjiong; Ge, Quansheng

    2013-09-01

    Phenological data of 42 woody plants in a temperate deciduous forest from the Chinese Phenological Observation Network (CPON) and the corresponding meteorological data from 1963 to 2011 in Xi'an, Shaanxi Province, China were collected and analyzed. The first leaf date (FLD), leaf coloring date (LCD) and first flower date (FFD) are revealed as strong biological signals of climatic change. The FLD, LCD and FFD of most species are sensitive to average temperature during a certain period before phenophase onset. Regional precipitation also has a significant impact on phenophases of about half of the species investigated. Affected by climate change, the FLD and FFD of these species have advanced by 5.54 days and 10.20 days on average during 2003-2011 compared with the period 1963-1996, respectively. Meanwhile, the LCD has delayed by 10.59 days, and growing season length has extended 16.13 days. Diverse responses of phenology commonly exist among different species and functional groups during the study period. Especially for FFD, the deviations between the above two periods ranged from -20.68 to -2.79 days; biotic pollination species showed a significantly greater advance than abiotic pollination species. These results were conducive to the understanding of possible changes in both the structure of plant communities and interspecific relationships in the context of climate change.

  3. Alluvial fan response to climatic change: Insights from numerical modeling (Invited)

    NASA Astrophysics Data System (ADS)

    Pelletier, J. D.

    2009-12-01

    Alluvial fans in the western U.S. exhibit a regionally correlative sequence of Plio-Quaternary deposits. Cosmogenic and U-series dating has greatly improved the age control on these deposits and their associated terraces and generally strengthened the case for aggradation during humid-to-arid transitions. Still, the linkages between climate change, upland basin response, and alluvial fan response are not well constrained. Fans may fill and cut as a result of autogenetic processes/internal adjustments, changes in regional temperature (which controls snowmelt-induced flooding), changes in the frequency-size distribution of rainfall events, and/or changes in upslope vegetation. Here I describe the results of a numerical modeling study designed to better constrain the relationships between different end-member forcing mechanisms and the geologic record of alluvial fan deposits and terraces. The model solves the evolution of the fan topography using Exner's equation (conservation of mass) coupled with a nonlinear, threshold-controlled transport relation for sand and gravel. Bank retreat is modeled using an advection equation with a rate proportional to bank shear stress. I begin by considering the building of a fan under conditions of constant water and sediment supply. This simple system exhibits all of the complexity of fans developed under experimental conditions, and it provides insights into the mechanisms that control avulsions and it provides a baseline estimate for the within-fan relief that can result from autogenetic processes. Relationships between the magnitude and period of variations in the sediment-to-water ratio and the geomorphic response of fans are then discussed. I also consider the response of a coupled drainage basin-fan system to changes in climate, including the hydrologic and vegetation response of upland hillslopes. Fans can aggrade or incise in response to the same climatic event depending on the relief of the upstream drainage basin, which

  4. Climate Responses to Changes in Land-surface Properties due to Wildfires

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Hao, X.; Qu, J. J.

    2015-12-01

    Wildfires can feedback the atmosphere by impacting atmospheric radiation transfer and cloud microphysics through emitting smoke particles and the land-air heat and water fluxes through modifying land-surface properties. While the impacts through smoke particles have been extensively investigated recently, very few studies have been conducted to examine the impacts through land-surface property change. This study is to fill this gap by examining the climate responses to the changes in land-surface properties induced by several large wildfires in the United States. Satellite remote sensing tools including MODIS and Landsat are used to quantitatively evaluate the land-surface changes characterized by reduced vegetation coverage and increased albedo over long post-fire periods. Variations in air and soil temperature and moisture of the burned areas are also monitored. Climate modeling is conducted to simulate climate responses and understand the related physical processes and interactions. The preliminary results indicate noticeable changes in water and heat transfers from the ground to the atmosphere through several mechanisms. Larger albedo reduces solar radiation absorbed on the ground, leading to less energy for latent and sensible heat fluxes. With smaller vegetation coverage, water transfer from the soil to the atmosphere through transpiration is reduced. Meanwhile, the Bowen ratio becomes larger after burning and therefore more solar energy absorbed on the ground is converted into sensible heat instead of being used as latent energy for water phase change. In addition, reduced vegetation coverage reduces roughness and increases wind speed, which modify dynamic resistances to water and heat movements. As a result of the changes in the land-air heat and water fluxes, clouds and precipitation as well as other atmospheric processes are affected by wildfires.

  5. Microbial community responses to temperature increase the potential for soil carbon losses under climate change.

    NASA Astrophysics Data System (ADS)

    Hartley, Iain; Karhu, Kristiina; Auffret, Marc; Hopkins, David; Prosser, Jim; Singh, Brajesh; Subke, Jens-Arne; Wookey, Philip; Ågren, Göran

    2014-05-01

    There are concerns that global warming may stimulate decomposition rates in soils, with the extra CO2 released representing a positive feedback to climate change. However, there is growing recognition that adaptation of soil microbial communities to temperature changes may alter the potential rate of carbon release. Critically, recent studies have produced conflicting results in terms of whether the medium-term soil microbial community response to temperature reduces (compensatory thermal adaptation) or enhances (enhancing thermal adaptation) the instantaneous direct positive effects of temperature on microbial activity. This lack of understanding adds considerably to uncertainty in predictions of the magnitude and direction of carbon-cycle feedbacks to climate change. In this talk, I present results from one of the most extensive investigations ever undertaken into the role that microbial adaptation plays in controlling the temperature sensitivity of decomposition. Soils were collected from a range of ecosystem types, representing a thermal gradient from the Arctic to the Amazon. Our novel soil-cooling approach minimises issues associated with substrate depletion in warming studies, but still tests whether adaptation enhances or reduces the direct impact of temperature changes on microbial activity. We also investigated the mechanisms underlying changes in microbial respiration by quantifying changes in microbial community composition, microbial biomass, mass-specific activity, carbon-use efficiency, and enzyme activities. Our results indicate that enhancing responses are much more common than compensatory thermal acclimation, with the latter being observed in less than 10% of cases. However, identifying the mechanisms underlying enhancing and compensatory adaptation remained elusive. No consistent changes were observed in terms of mass-specific activity, biomass or enzyme activity, indicating that current theory is inadequate in explaining observed patterns

  6. Grassland/atmosphere response to changing climate: Coupling regional and local scales. Final report

    SciTech Connect

    Coughenour, M.B.; Kittel, T.G.F.; Pielke, R.A.; Eastman, J.

    1993-10-01

    The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C{sub 3} temperate grasslands wig respond more strongly to elevated CO{sub 2} than temperate C{sub 4} grasslands in the short-term while a large positive N-PP response was predicted for a C{sub 4} Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO{sub 2} is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO{sub 2} GCM Simulations revealed relatively small differences.

  7. Styles of glaciation on Kilimanjaro, Tanzania, in response to late Quaternary climate change

    NASA Astrophysics Data System (ADS)

    Boston, Clare; Lovell, Harold; Mills, Stephanie; Cullen, Nicolas; Sirguey, Pascal

    2016-04-01

    The recognition of geomorphological evidence for more extensive ice masses in a number of areas near the equator provides a direct link to climate change in the tropics. Kilimanjaro in Tanzania consists of the highest elevations in Africa, and sets of moraines document that ice was significantly more extensive in the past. The most extensive moraines around Kibo, the highest peak, suggest that glaciers may have extended down to around 3800 m at the Last Glacial Maximum (LGM). A more recent set of moraines, at 4600-4800 m on the western side of the peak, document the maximum position that ice reached during the Little Ice Age (LIA). Both of these sets of moraines indicate significant recession has occurred throughout the late Quaternary, and particularly during the 20th century. Present-day ice is restricted to rapidly-receding glaciers and icefields on the uppermost flanks and summit of Kibo, between ~5000-5800 m. The area is therefore important for understanding the timing, magnitude and style of glacier response to changes in climate in the tropics in the late Quaternary. This research presents the results of new field and remotely-sensed mapping of moraines relating to the Late Pleistocene and LIA, providing greater detail on the glacial geomorphology of the area than in previous mapping. This allows an assessment of the styles of glaciation, and particularly the role of topography and aspect on influencing response to climate and patterns of glacier recession.

  8. Antarctic Climate Change: Extreme Events Disrupt Plastic Phenotypic Response in Adélie Penguins

    PubMed Central

    Lescroël, Amélie; Ballard, Grant; Grémillet, David; Authier, Matthieu; Ainley, David G.

    2014-01-01

    In the context of predicted alteration of sea ice cover and increased frequency of extreme events, it is especially timely to investigate plasticity within Antarctic species responding to a key environmental aspect of their ecology: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins (Pygoscelis adeliae) breeding in the Ross Sea. A ‘natural experiment’ brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The ‘natural experiment’ uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise. PMID:24489657

  9. Antarctic climate change: extreme events disrupt plastic phenotypic response in Adélie penguins.

    PubMed

    Lescroël, Amélie; Ballard, Grant; Grémillet, David; Authier, Matthieu; Ainley, David G

    2014-01-01

    In the context of predicted alteration of sea ice cover and increased frequency of extreme events, it is especially timely to investigate plasticity within Antarctic species responding to a key environmental aspect of their ecology: sea ice variability. Using 13 years of longitudinal data, we investigated the effect of sea ice concentration (SIC) on the foraging efficiency of Adélie penguins (Pygoscelis adeliae) breeding in the Ross Sea. A 'natural experiment' brought by the exceptional presence of giant icebergs during 5 consecutive years provided unprecedented habitat variation for testing the effects of extreme events on the relationship between SIC and foraging efficiency in this sea-ice dependent species. Significant levels of phenotypic plasticity were evident in response to changes in SIC in normal environmental conditions. Maximum foraging efficiency occurred at relatively low SIC, peaking at 6.1% and decreasing with higher SIC. The 'natural experiment' uncoupled efficiency levels from SIC variations. Our study suggests that lower summer SIC than currently observed would benefit the foraging performance of Adélie penguins in their southernmost breeding area. Importantly, it also provides evidence that extreme climatic events can disrupt response plasticity in a wild seabird population. This questions the predictive power of relationships built on past observations, when not only the average climatic conditions are changing but the frequency of extreme climatic anomalies is also on the rise. PMID:24489657

  10. Potential for evolutionary responses to climate change – evidence from tree populations

    PubMed Central

    Alberto, Florian J; Aitken, Sally N; Alía, Ricardo; González-Martínez, Santiago C; Hänninen, Heikki; Kremer, Antoine; Lefèvre, François; Lenormand, Thomas; Yeaman, Sam; Whetten, Ross; Savolainen, Outi

    2013-01-01

    Evolutionary responses are required for tree populations to be able to track climate change. Results of 250 years of common garden experiments show that most forest trees have evolved local adaptation, as evidenced by the adaptive differentiation of populations in quantitative traits, reflecting environmental conditions of population origins. On the basis of the patterns of quantitative variation for 19 adaptation-related traits studied in 59 tree species (mostly temperate and boreal species from the Northern hemisphere), we found that genetic differentiation between populations and clinal variation along environmental gradients were very common (respectively, 90% and 78% of cases). Thus, responding to climate change will likely require that the quantitative traits of populations again match their environments. We examine what kind of information is needed for evaluating the potential to respond, and what information is already available. We review the genetic models related to selection responses, and what is known currently about the genetic basis of the traits. We address special problems to be found at the range margins, and highlight the need for more modeling to understand specific issues at southern and northern margins. We need new common garden experiments for less known species. For extensively studied species, new experiments are needed outside the current ranges. Improving genomic information will allow better prediction of responses. Competitive and other interactions within species and interactions between species deserve more consideration. Despite the long generation times, the strong background in quantitative genetics and growing genomic resources make forest trees useful species for climate change research. The greatest adaptive response is expected when populations are large, have high genetic variability, selection is strong, and there is ecological opportunity for establishment of better adapted genotypes. PMID:23505261

  11. Assessing the implications of human land-use change for the transient climate response to cumulative carbon emissions

    NASA Astrophysics Data System (ADS)

    Simmons, C. T.; Matthews, H. D.

    2016-03-01

    Recent research has shown evidence of a linear climate response to cumulative CO2 emissions, which implies that the source, timing, and amount of emissions does not significantly influence the climate response per unit emission. Furthermore, these analyses have generally assumed that the climate response to land-use CO2 emissions is equivalent to that of fossil fuels under the assumption that, once in the atmosphere, the radiative forcing induced by CO2 is not sensitive to the emissions source. However, land-cover change also affects surface albedo and the strength of terrestrial carbon sinks, both of which have an additional climate effect. In this study, we use a coupled climate-carbon cycle model to assess the climate response to historical and future cumulative land-use CO2 emissions, in order to compare it to the response to fossil fuel CO2. We find that when we isolate the CO2-induced (biogeochemical) temperature changes associated with land-use change, then the climate response to cumulative land-use emissions is equivalent to that of fossil fuel CO2. We show further that the globally-averaged albedo-induced biophysical cooling from land-use change is non-negligible and may be of comparable magnitude to the biogeochemical warming, with the result that the net climate response to land-use change is substantially different from a linear response to cumulative emissions. However, our new simulations suggest that the biophysical cooling from land-use change follows its own independent (negative) linear response to cumulative net land-use CO2 emissions, which may provide a useful scaling factor for certain applications when evaluating the full transient climate response to emissions.

  12. Shorebird Migration Patterns in Response to Climate Change: A Modeling Approach

    NASA Technical Reports Server (NTRS)

    Smith, James A.

    2010-01-01

    The availability of satellite remote sensing observations at multiple spatial and temporal scales, coupled with advances in climate modeling and information technologies offer new opportunities for the application of mechanistic models to predict how continental scale bird migration patterns may change in response to environmental change. In earlier studies, we explored the phenotypic plasticity of a migratory population of Pectoral sandpipers by simulating the movement patterns of an ensemble of 10,000 individual birds in response to changes in stopover locations as an indicator of the impacts of wetland loss and inter-annual variability on the fitness of migratory shorebirds. We used an individual based, biophysical migration model, driven by remotely sensed land surface data, climate data, and biological field data. Mean stop-over durations and stop-over frequency with latitude predicted from our model for nominal cases were consistent with results reported in the literature and available field data. In this study, we take advantage of new computing capabilities enabled by recent GP-GPU computing paradigms and commodity hardware (general purchase computing on graphics processing units). Several aspects of our individual based (agent modeling) approach lend themselves well to GP-GPU computing. We have been able to allocate compute-intensive tasks to the graphics processing units, and now simulate ensembles of 400,000 birds at varying spatial resolutions along the central North American flyway. We are incorporating additional, species specific, mechanistic processes to better reflect the processes underlying bird phenotypic plasticity responses to different climate change scenarios in the central U.S.

  13. Response of plants and ecosystems to CO{sub 2} and climate change. Final technical report

    SciTech Connect

    Reynolds, J.F.

    1993-12-31

    In recognition of the important role of vegetation in the bio-geosphere carbon cycle, the Carbon Dioxide Research Program of the US Department of Energy established the research program: Direct Effects of increasing Carbon Dioxide on Vegetation. The ultimate goal is to develop a general ecosystem model to investigate, via hypothesis testing, the potential responses of different terrestrial ecosystems to changes in the global environment over the next century. The approach involves the parallel development of models at several hierarchical levels, from the leaf to the ecosystem. At the plant level, mechanism and the direct effects of CO{sub 2} in the development of a general plant growth model, GEPSI - GEneral Plant SImulator has been stressed. At the ecosystem level, we have stressed the translation Of CO{sub 2} effects and other aspects of climate change throughout the ecosystem, including feedbacks and constraints to system response, in the development of a mechanistic, general ecosystem model SERECO - Simulation of Ecosystem Response to Elevated CO{sub 2} and Climate Change has been stressed.

  14. Highly contrasted responses of Mediterranean octocorals to climate change along a depth gradient

    PubMed Central

    Pivotto, I. D.; Nerini, D.; Masmoudi, M.; Kara, H.; Chaoui, L.; Aurelle, D.

    2015-01-01

    Climate change has a strong impact on marine ecosystems, including temperate species. Analysing the diversity of thermotolerance levels within species along with their genetic structure enables a better understanding of their potential response to climate change. We performed this integrative study on the Mediterranean octocoral Eunicella cavolini, with samples from different depths and by means of a common garden experiment. This species does not host photosynthetic Symbiodinium, enabling us to focus on the cnidarian response. We compared the thermotolerance of individuals from 20 m and 40 m depths from the same site and with replicates from the same colony. On the basis of an innovative statistical analysis of necrosis kinetics and risk, we demonstrated the occurrence of a very different response between depths at this local scale, with lower thermotolerance of deep individuals. Strongly thermotolerant individuals were observed at 20 m with necrosis appearing at higher temperatures than observed in situ. On the basis of nine microsatellite loci, we showed that these marked thermotolerance differences occur within a single population. This suggests the importance of acclimatization processes in adaptation to these different depths. In addition, differences between replicates demonstrated the occurrence of a variability of response between fragments from the same colony with the possibility of an interaction with a tank effect. Our results provide a basis for studying adaptation and acclimatization in Mediterranean octocorals in a heterogeneous environment. PMID:26064654

  15. Integrated watershed-scale response to climate change for selected basins across the United States

    USGS Publications Warehouse

    Markstrom, Steven L.; Hay, Lauren E.; Ward-Garrison, D. Christian; Risley, John C.; Battaglin, William A.; Bjerklie, David M.; Chase, Katherine J.; Christiansen, Daniel E.; Dudley, Robert W.; Hunt, Randall J.; Koczot, Kathryn M.; Mastin, Mark C.; Regan, R. Steven; Viger, Roland J.; Vining, Kevin C.; Walker, John F.

    2012-01-01

    A study by the U.S. Geological Survey (USGS) evaluated the hydrologic response to different projected carbon emission scenarios of the 21st century using a hydrologic simulation model. This study involved five major steps: (1) setup, calibrate and evaluated the Precipitation Runoff Modeling System (PRMS) model in 14 basins across the United States by local USGS personnel; (2) acquire selected simulated carbon emission scenarios from the World Climate Research Programme's Coupled Model Intercomparison Project; (3) statistical downscaling of these scenarios to create PRMS input files which reflect the future climatic conditions of these scenarios; (4) generate PRMS projections for the carbon emission scenarios for the 14 basins; and (5) analyze the modeled hydrologic response. This report presents an overview of this study, details of the methodology, results from the 14 basin simulations, and interpretation of these results. A key finding is that the hydrological response of the different geographical regions of the United States to potential climate change may be different, depending on the dominant physical processes of that particular region. Also considered is the tremendous amount of uncertainty present in the carbon emission scenarios and how this uncertainty propagates through the hydrologic simulations.

  16. Water Demands with Two Adaptation Responses to Climate Change in a Mexican Irrigation District

    NASA Astrophysics Data System (ADS)

    Ojeda, W.; Iñiguez-Covarrubias, M.; Rojano, A.

    2012-12-01

    It is well documented that climate change is inevitable and that farmers need to adapt to changes in projected climate. Changes in water demands for a Mexican irrigation district were assessed using an irrigation scheduling model. The impact of two adaptations actions on water demands were estimated and compared with a baseline scenario. Wet and dry cropping plans were selected from the last 15 water years with actual climatology (1961-1990) taken as reference and three A1B climate change projection periods P1, P2 and P3 (2011-2040, 2041-2070, and 2071-2098). Projected precipitation and air temperature (medium, maximum and minimum) data were obtained through weighted averages of the best CGCM projections for Mexico, available at the IPCC data distribution center, using the Reliability Ensemble Averaging method (REA). Two adaptation farmers' responses were analyzed: use of longer season varieties and reduction of planting dates toward colder season as warming intensifies in the future. An annual accumulated ETo value of 1554 mm was estimated for the base period P0. Cumulative and Daily irrigations demands were generated for each agricultural season using the four climate projection series and considering adaptations actions. Figure 1 integrates in a unique net flow curve for the Fall-Winter season under selected adaptations actions. The simulation results indicated that for mid century (Period P2), the use of longer-season cultivars (AV) will have more pronounced effect in daily net flow based than the reduction of planting season (APS) as climate change intensifies during present century. Without adaptation (WA), the increase in temperature will shorten the growing season of all annual crops, generating a peak shift with respect to reference case (WA-P0). Combined adoptions of adaptation actions (AP+V) can generate higher, peak and cumulative, crop water requirements than actual values as Figure 1 shows. There are clear trends that without adaptations, water

  17. Eolian sediment responses to late Quaternary climate changes: Temporal and spatial patterns in the Sahara

    USGS Publications Warehouse

    Swezey, C.

    2001-01-01

    This paper presents a compilation of eolian-based records of late Quaternary climate changes in the Sahara. Although the data are relatively sparse, when viewed as a whole, they reveal a general pattern of widespread eolian sediment mobilization prior to 11,000 cal. years BP, eolian sediment stabilization from 11,000 to 5000 cal. years BP, and a return to widespread eolian sediment mobilization after 5000 cal. years BP. Furthermore, an eolian-based record from southern Tunisia reveals the existence of millennial-scale changes in eolian sediment behavior. These millennial-scale variations provide examples of eolian sediment responses to climate changes at a scale intermediate between seasonal and orbital ('Milankovitch') changes, and they are also coincident with abrupt atmospheric and oceanic changes. The general synchroneity of the eolian stratigraphic records and their coincidence with various oceanic and atmospheric changes suggest that global forcing mechanisms have influenced late Quaternary eolian sediment behavior in the Sahara. ?? 2001 Elsevier Science B.V.

  18. Response of high-elevation forests in the Olympic Mountains to climatic change

    USGS Publications Warehouse

    Zolbrod, A.N.; Peterson, D.L.

    1999-01-01

    The gap model ZELIG was used to examine the effects of increased temperature (2A?C) and altered precipitation on high-elevation ecosystems of the Olympic Mountains, Washington, U.S.A. Changes in tree species distribution and abundance, as well as stand biomass, were examined on north and south aspects in the dry northeast (NE) and wet southwest (SW) regions of the Olympics for (i) warmer, (ii) warmer and 20% wetter, and (iii) warmer and 20% drier climatic-change scenarios. Dominant tree species shift upwards 300-600 m in elevation in the SW, with subalpine meadows and Tsuga mertensiana (Bong.) Carr. forests being replaced by Abies amabilis (Dougl.) Forbes forests at higher elevations and A. amabilis forests being replaced by Tsuga heterophylla (Raf.) Sarg. forests at lower elevations. In the NE, drought-tolerant species become dominant approximately 200 m lower than present, with A. lasiocarpa dominating the north aspect and Pinus contorta Dougl. ex Loud. the south aspect. Biomass increases in the SW and generally decreases in the NE, depending on aspect and precipitation regime. This study suggests that species and site-specific responses at mesoscale (e.g., wet vs. dry climatic regime) and microscale (e.g., north vs. south aspect) resolutions must be characterized to quantify the variation in potential effects of climatic change on forest vegetation in mountainous regions.

  19. Climate Change Schools Project...

    ERIC Educational Resources Information Center

    McKinzey, Krista

    2010-01-01

    This article features the award-winning Climate Change Schools Project which aims to: (1) help schools to embed climate change throughout the national curriculum; and (2) showcase schools as "beacons" for climate change teaching, learning, and positive action in their local communities. Operating since 2007, the Climate Change Schools Project…

  20. Plant response to climate change along the forest-tundra ecotone in northeastern Siberia.

    PubMed

    Berner, Logan T; Beck, Pieter S A; Bunn, Andrew G; Goetz, Scott J

    2013-11-01

    Russia's boreal (taiga) biome will likely contract sharply and shift northward in response to 21st century climatic change, yet few studies have examined plant response to climatic variability along the northern margin. We quantified climate dynamics, trends in plant growth, and growth-climate relationships across the tundra shrublands and Cajander larch (Larix cajanderi Mayr.) woodlands of the Kolyma river basin (657 000 km(2) ) in northeastern Siberia using satellite-derived normalized difference vegetation indices (NDVI), tree ring-width measurements, and climate data. Mean summer temperatures (Ts ) increased 1.0 °C from 1938 to 2009, though there was no trend (P > 0.05) in growing year precipitation or climate moisture index (CMIgy ). Mean summer NDVI (NDVIs ) increased significantly from 1982 to 2010 across 20% of the watershed, primarily in cold, shrub-dominated areas. NDVIs positively correlated (P < 0.05) with Ts across 56% of the watershed (r = 0.52 ± 0.09, mean ± SD), principally in cold areas, and with CMIgy across 9% of the watershed (r = 0.45 ± 0.06), largely in warm areas. Larch ring-width measurements from nine sites revealed that year-to-year (i.e., high-frequency) variation in growth positively correlated (P < 0.05) with June temperature (r = 0.40) and prior summer CMI (r = 0.40) from 1938 to 2007. An unexplained multi-decadal (i.e., low-frequency) decline in annual basal area increment (BAI) occurred following the mid-20th century, but over the NDVI record there was no trend in mean BAI (P > 0.05), which significantly correlated with NDVIs (r = 0.44, P < 0.05, 1982-2007). Both satellite and tree-ring analyses indicated that plant growth was constrained by both low temperatures and limited moisture availability and, furthermore, that warming enhanced growth. Impacts of future climatic change on forests near treeline in Arctic Russia will likely be influenced by shifts in both temperature and moisture, which implies

  1. Changes in biocrust cover drive carbon cycle responses to climate change in drylands

    PubMed Central

    Maestre, Fernando T.; Escolar, Cristina; de Guevara, Mónica Ladrón; Quero, José L.; Lázaro, Roberto; Delgado-Baquerizo, Manuel; Ochoa, Victoria; Berdugo, Miguel; Gozalo, Beatriz; Gallardo, Antonio

    2013-01-01

    Dryland ecosystems account for ~27% of global soil organic carbon (C) reserves, yet it is largely unknown how climate change will impact C cycling and storage in these areas. In drylands, soil C concentrates at the surface, making it particularly sensitive to the activity of organisms inhabiting the soil uppermost levels, such as communities dominated by lichens, mosses, bacteria and fungi (biocrusts). We conducted a full factorial warming and rainfall exclusion experiment at two semiarid sites in Spain to show how an average increase of air temperature of 2–3°C promoted a drastic reduction in biocrust cover (~ 44% in four years). Warming significantly increased soil CO2 efflux, and reduced soil net CO2 uptake, in biocrust-dominated microsites. Losses of biocrust cover with warming through time were paralleled by increases in recalcitrant C sources, such as aromatic compounds, and in the abundance of fungi relative to bacteria. The dramatic reduction in biocrust cover with warming will lessen the capacity of drylands to sequester atmospheric CO2. This decrease may act synergistically with other warming-induced effects, such as the increase in soil CO2 efflux and the changes in microbial communities, to alter C cycling in drylands, and to reduce soil C stocks in the mid to long term. PMID:23818331

  2. Changes in biocrust cover drive carbon cycle responses to climate change in drylands.

    PubMed

    Maestre, Fernando T; Escolar, Cristina; de Guevara, Mónica Ladrón; Quero, José L; Lázaro, Roberto; Delgado-Baquerizo, Manuel; Ochoa, Victoria; Berdugo, Miguel; Gozalo, Beatriz; Gallardo, Antonio

    2013-12-01

    Dryland ecosystems account for ca. 27% of global soil organic carbon (C) reserves, yet it is largely unknown how climate change will impact C cycling and storage in these areas. In drylands, soil C concentrates at the surface, making it particularly sensitive to the activity of organisms inhabiting the soil uppermost levels, such as communities dominated by lichens, mosses, bacteria and fungi (biocrusts). We conducted a full factorial warming and rainfall exclusion experiment at two semiarid sites in Spain to show how an average increase of air temperature of 2-3 °C promoted a drastic reduction in biocrust cover (ca. 44% in 4 years). Warming significantly increased soil CO2 efflux, and reduced soil net CO2 uptake, in biocrust-dominated microsites. Losses of biocrust cover with warming through time were paralleled by increases in recalcitrant C sources, such as aromatic compounds, and in the abundance of fungi relative to bacteria. The dramatic reduction in biocrust cover with warming will lessen the capacity of drylands to sequester atmospheric CO2 . This decrease may act synergistically with other warming-induced effects, such as the increase in soil CO2 efflux and the changes in microbial communities to alter C cycling in drylands, and to reduce soil C stocks in the mid to long term. PMID:23818331

  3. Surface elevation change and vegetation distribution dynamics in a subtropical coastal wetland: Implications for coastal wetland response to climate change

    NASA Astrophysics Data System (ADS)

    Rogers, Kerrylee; Saintilan, Neil; Woodroffe, Colin D.

    2014-08-01

    The response of coastal wetlands to sea-level rise is receiving global attention and observed changes in the distribution of mangrove and salt marsh are increasingly associated with global climate change, particularly sea-level and temperature rise, and potentially elevated carbon dioxide. Processes operating over smaller-spatial scales, such as rainfall variability and nutrient enrichment are also proposed as possible short-term drivers of changes in the distribution of mangrove and salt marsh. We consider the response of mangrove and salt marsh in a subtropical estuary to changes in environmental variables over a 12 year period by comparing rates of surface elevation change and vegetation distribution dynamics to hydrological and climatic variables, specifically water level and rainfall. This period of analysis captured inter-annual variability in sea level and rainfall associated with different phases of the El Niño Southern Oscillation (ENSO). We found that the mangrove and salt marsh trend of increasing elevation was primarily controlled by position within the tidal prism, in this case defined by inundation depth and distance to the tidal channel. Rainfall was not a primary driver of elevation trends in mangrove and salt marsh, but rainfall and water level variability did influence variability in elevation over the study period, though cross-correlation of these factors confounds identification of a single process driving this variability. These results highlight the scale-dependence of coastal wetland vegetation distribution dynamics; the longer-term trend of surface elevation increase and mangrove encroachment of salt marsh correlated with global sea-level trends, while short-term variability in surface elevation was related to local variability in water level and rainfall. Rates of surface elevation increase were found to lag behind rates of water level change within the Tweed River, which may facilitate further expansion of mangrove into salt marsh. This

  4. Response of deciduous trees spring phenology to recent and projected climate change in Central Lithuania

    NASA Astrophysics Data System (ADS)

    Juknys, Romualdas; Kanapickas, Arvydas; Šveikauskaitė, Irma; Sujetovienė, Gintarė

    2016-03-01

    The analysis of long-term time series of spring phenology for different deciduous trees species has shown that leaf unfolding for all the investigated species is the most sensitive to temperatures in March and April and illustrates that forcing temperature is the main driver of the advancement of leaf unfolding. Available chilling amount has increased by 22.5 % over the last 90 years, indicating that in the investigated geographical region there is no threat of chilling shortage. The projection of climatic parameters for Central Lithuania on the basis of three global circulation models has shown that under the optimistic climate change scenario (RCP 2.6) the mean temperature tends to increase by 1.28 °C and under the pessimistic scenario (RCP 8.5) by 5.03 °C until the end of the current century. Recently, different statistical models are used not only to analyze but also to project the changes in spring phenology. Our study has shown that when the data of long-term phenological observations are available, multiple regression models are suitable for the projection of the advancement of leaf unfolding under the changing climate. According to the RCP 8.5 scenario, the projected advancement in leaf unfolding for early-season species birch consists of almost 15 days as an average of all three used GSMs. Markedly less response to the projected far future (2071-2100), climate change is foreseen for other investigated climax species: -9 days for lime, 10 days for oak, and 11 days for maple.

  5. The trophic responses of two different rodent–vector–plague systems to climate change

    PubMed Central

    Xu, Lei; Schmid, Boris V.; Liu, Jun; Si, Xiaoyan; Stenseth, Nils Chr.; Zhang, Zhibin

    2015-01-01

    Plague, the causative agent of three devastating pandemics in history, is currently a re-emerging disease, probably due to climate change and other anthropogenic changes. Without understanding the response of plague systems to anthropogenic or climate changes in their trophic web, it is unfeasible to effectively predict years with high risks of plague outbreak, hampering our ability for effective prevention and control of the disease. Here, by using surveillance data, we apply structural equation modelling to reveal the drivers of plague prevalence in two very different rodent systems: those of the solitary Daurian ground squirrel and the social Mongolian gerbil. We show that plague prevalence in the Daurian ground squirrel is not detectably related to its trophic web, and that therefore surveillance efforts should focus on detecting plague directly in this ecosystem. On the other hand, plague in the Mongolian gerbil is strongly embedded in a complex, yet understandable trophic web of climate, vegetation, and rodent and flea densities, making the ecosystem suitable for more sophisticated low-cost surveillance practices, such as remote sensing. As for the trophic webs of the two rodent species, we find that increased vegetation is positively associated with higher temperatures and precipitation for both ecosystems. We furthermore find a positive association between vegetation and ground squirrel density, yet a negative association between vegetation and gerbil density. Our study thus shows how past surveillance records can be used to design and improve existing plague prevention and control measures, by tailoring them to individual plague foci. Such measures are indeed highly needed under present conditions with prevailing climate change. PMID:25540277

  6. The trophic responses of two different rodent-vector-plague systems to climate change.

    PubMed

    Xu, Lei; Schmid, Boris V; Liu, Jun; Si, Xiaoyan; Stenseth, Nils Chr; Zhang, Zhibin

    2015-02-01

    Plague, the causative agent of three devastating pandemics in history, is currently a re-emerging disease, probably due to climate change and other anthropogenic changes. Without understanding the response of plague systems to anthropogenic or climate changes in their trophic web, it is unfeasible to effectively predict years with high risks of plague outbreak, hampering our ability for effective prevention and control of the disease. Here, by using surveillance data, we apply structural equation modelling to reveal the drivers of plague prevalence in two very different rodent systems: those of the solitary Daurian ground squirrel and the social Mongolian gerbil. We show that plague prevalence in the Daurian ground squirrel is not detectably related to its trophic web, and that therefore surveillance efforts should focus on detecting plague directly in this ecosystem. On the other hand, plague in the Mongolian gerbil is strongly embedded in a complex, yet understandable trophic web of climate, vegetation, and rodent and flea densities, making the ecosystem suitable for more sophisticated low-cost surveillance practices, such as remote sensing. As for the trophic webs of the two rodent species, we find that increased vegetation is positively associated with higher temperatures and precipitation for both ecosystems. We furthermore find a positive association between vegetation and ground squirrel density, yet a negative association between vegetation and gerbil density. Our study thus shows how past surveillance records can be used to design and improve existing plague prevention and control measures, by tailoring them to individual plague foci. Such measures are indeed highly needed under present conditions with prevailing climate change. PMID:25540277

  7. Climate of origin affects tick (Ixodes ricinus) host-seeking behavior in response to temperature: implications for resilience to climate change?

    PubMed Central

    Gilbert, Lucy; Aungier, Jennifer; Tomkins, Joseph L

    2014-01-01

    Climate warming is changing distributions and phenologies of many organisms and may also impact on vectors of disease-causing pathogens. In Europe, the tick Ixodes ricinus is the primary vector of medically important pathogens (e.g., Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis). How might climate change affect I. ricinus host-seeking behavior (questing)? We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. We predicted that ticks from cooler climates quest at cooler temperatures than those from warmer climates. This would suggest that I. ricinus can adapt and therefore have the potential to be resilient to climate change. I. ricinus were collected from a cline of climates using a latitudinal gradient (northeast Scotland, North Wales, South England, and central France). Under laboratory conditions, ticks were subjected to temperature increases of 1°C per day, from 6 to 15°C. The proportion of ticks questing was recorded five times per temperature (i.e., per day). The theoretical potential to quest was then estimated for each population over the year for future climate change projections. As predicted, more ticks from cooler climates quested at lower temperatures than did ticks from warmer climates. The proportion of ticks questing was strongly associated with key climate parameters from each location. Our projections, based on temperature alone, suggested that populations could advance their activity season by a month under climate change, which has implications for exposure periods of hosts to tick-borne pathogens. Our findings suggest that I. ricinus have adapted their behavior in response to climate, implying some potential to adapt to climate change. Predictive models of I. ricinus dynamics and disease risk over continental scales would benefit from knowledge of these differences between populations. PMID:24772293

  8. The Response of Different Audiences to Place-based Communication about the Role of Climate Change in Extreme Weather Events

    NASA Astrophysics Data System (ADS)

    Halperin, A.; Walton, P.

    2015-12-01

    As the science of extreme event attribution grows, there is an increasing need to understand how the public responds to this type of climate change communication. Extreme event attribution has the unprecedented potential to locate the effects of climate change in the here and now, but there is little information about how different facets of the public might respond to these local framings of climate change. Drawing on theories of place attachment and psychological distance, this paper explores how people with different beliefs and values shift their willingness to mitigate and adapt to climate change in response to local or global communication of climate change impacts. Results will be presented from a recent survey of over 600 Californians who were each presented with one of three experimental conditions: 1) a local framing of the role of climate change in the California drought 2) a global framing of climate change and droughts worldwide, or 3) a control condition of no text. Participants were categorized into groups based on their prior beliefs about climate change according to the Six Americas classification scheme (Leiserowitz et al., 2011). The results from the survey in conjunction with qualitative results from follow-up interviews shed insight into the importance of place in communicating climate change for people in each of the Six Americas. Additional results examine the role of gender and political affiliation in mediating responses to climate change communication. Despite research that advocates unequivocally for local framing of climate change, this study offers a more nuanced perspective of under which circumstances extreme event attribution might be an effective tool for changing behaviors. These results could be useful for scientists who wish to gain a better understanding of how their event attribution research is perceived or for educators who want to target their message to audiences where it could have the most impact.

  9. Electricity for groundwater use: constraints and opportunities for adaptive response to climate change

    NASA Astrophysics Data System (ADS)

    Scott, Christopher A.

    2013-09-01

    Globally, groundwater use is intensifying to meet demands for irrigation, urban supply, industrialization, and, in some instances, electrical power generation. In response to hydroclimatic variability, surface water is being substituted with groundwater, which must be viewed as a strategic resource for climate adaptation. In this sense, the supply of electricity for pumping is an adaptation policy tool. Additionally, planning for climate-change mitigation must consider CO2 emissions resulting from pumping. This paper examines the influence of electricity supply and pricing on groundwater irrigation and resulting emissions, with specific reference to Mexico—a climate-water-energy ‘perfect storm’. Night-time power supply at tariffs below the already-subsidized rates for agricultural groundwater use has caused Mexican farmers to increase pumping, reversing important water and electricity conservation gains achieved. Indiscriminate groundwater pumping, including for virtual water exports of agricultural produce, threatens the long-term sustainability of aquifers, non-agricultural water uses, and stream-aquifer interactions that sustain riparian ecosystems. Emissions resulting from agricultural groundwater pumping in Mexico are estimated to be 3.6% of total national emissions and are equivalent to emissions from transporting the same agricultural produce to market. The paper concludes with an assessment of energy, water, and climate trends coupled with policy futures to address these challenges.

  10. How is the River Water Quality Response to Climate Change Impacts?

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Willems, P.

    2015-12-01

    Water quality and its response to climate change have been become one of the most important issues of our society, which catches the attention of many scientists, environmental activists and policy makers. Climate change influences the river water quality directly and indirectly via rainfall and air temperature. For example, low flow decreases the volume of water for dilution and increases the residence time of the pollutants. By contrast, high flow leads to increases in the amount of pollutants and sediment loads from catchments to rivers. The changes in hydraulic characteristics, i.e. water depth and velocity, affect the transportation and biochemical transformation of pollutants in the river water body. The high air temperature leads to increasing water temperature, shorter growing periods of different crops and water demands from domestic households and industries, which eventually effects the level of river pollution. This study demonstrates the quantification of the variation of the water temperature and pollutant concentrations along the Molse Neet river in the North East of Belgium as a result of the changes in the catchment rainfall-runoff, air temperature and nutrient loads. Firstly, four climate change scenarios were generated based on a large ensemble of available global and regional climate models and statistical downscaling based on a quantile perturbation method. Secondly, the climatic changes to rainfall and temperature were transformed to changes in the evapotranspiration and runoff flow through the conceptual hydrological model PDM. Thirdly, the adjustment in nutrient loads from agriculture due to rainfall and growing periods of crops were calculated by means of the semi-empirical SENTWA model. Water temperature was estimated from air temperature by a stochastic model separating the temperature into long-term annual and short-term residual components. Next, hydrodynamic and water quality models of the river, implemented in InfoWorks RS, were

  11. Response of Florida shelf ecosystems to climate change: from macro to micro scales

    USGS Publications Warehouse

    Robbins, Lisa; Raabe, Ellen

    2010-01-01

    U.S. Geological Survey (USGS) research in St. Petersburg, Fla., is focusing attention on marine environments of the Florida shelf at three levels, from regional to estuarine to the individual organism. The USGS is partnering on this project with the Florida Department of Agriculture and Consumer Services (DACS), National Oceanic and Atmospheric Administration (NOAA), and the University of South Florida (USF) in marine studies. The specific goals of these combined efforts are an improved understanding of the effects of ocean acidification on regional carbonate processes, changes in individual estuaries, and organism-level response. This understanding will assist in developing appropriate Federal, State, and local management responses to climate change in coastal areas.

  12. Managing the global commons decision making and conflict resolution in response to climate change

    SciTech Connect

    Rayner, S. ); Naegeli, W.; Lund, P. )

    1990-07-01

    A workshop was convened to develop a better understanding of decision-making matters concerning management of the global commons and to resolve conflicts in response to climate change. This workshop report does not provide a narrative of the proceedings. The workshop program is included, as are the abstracts of the papers that were presented. Only the introductory paper on social science research by William Riebsame and the closing summary by Richard Rockwell are reprinted here. This brief report focuses instead on the deliberations of the working groups that developed during the workshop. 4 figs., 1 tab.

  13. Introduction to the symposium: responses of organisms to climate change: a synthetic approach to the role of thermal adaptation.

    PubMed

    Sears, Michael W; Angilletta, Michael J

    2011-11-01

    On a global scale, changing climates are affecting ecological systems across multiple levels of biological organization. Moreover, climates are changing at rates unprecedented in recent geological history. Thus, one of the most pressing concerns of the modern era is to understand the biological responses to climate such that society can both adapt and implement measures that attempt to offset the negative impacts of a rapidly changing climate. One crucial question, to understand organismal responses to climate, is whether the ability of organisms to adapt can keep pace with quickly changing environments. To address this question, a syntheses of knowledge from a broad set of biological disciplines will be needed that integrates information from the fields of ecology, behavior, physiology, genetics, and evolution. This symposium assembled a diverse group of scientists from these subdisciplines to present their perspectives regarding the ability of organisms to adapt to changing climates. Specifically, the goals of this symposia were to (1) highlight what each discipline brings to a discussion of organismal responses to climate, (2) to initiate and foster a discussion to break barriers in the transfer of knowledge across disciplines, and (3) to synthesize an approach to address ongoing issues concerning biological responses to climate. PMID:21880691

  14. Principals' Response to Change in Schools and Its Effect on School Climate

    ERIC Educational Resources Information Center

    Busch, Steve; Johnson, Shirley; Robles-Piña, Rebecca; Slate, John R.

    2009-01-01

    In this study, the researchers examined principal behaviors related with change in school climate. That is, the manner in which principals managed change within their schools and the impact of these change behaviors on the school climate was investigated. Through use of the Leadership Profile (Johnson, 2003) and the Organizational Health Inventory…

  15. Vertebrate records in polar sediments: Biological responses to past climate change and human activities

    NASA Astrophysics Data System (ADS)

    Sun, L. G.; Emslie, S. D.; Huang, T.; Blais, J. M.; Xie, Z. Q.; Liu, X. D.; Yin, X. B.; Wang, Y. H.; Huang, W.; Hodgson, D. A.; Smol, J. P.

    2013-11-01

    Biological responses to climate and environmental changes in remote polar regions are of increasing interest in global change research. Terrestrial and marine polar ecosystems have suffered from impacts of both rapid climate change and intense human activities, and large fluctuations in the population sizes of seabirds, seals, and Antarctic krill have been observed in the past decades. To understand the mechanisms driving these regime shifts in polar ecosystems, it is important to first distinguish the influences of natural forcing from anthropogenic activities. Therefore, investigations of past changes of polar ecosystems prior to human contact are relevant for placing recent human-induced changes within a long-term historical context. Here we focus our review on the fossil, sub-fossil, archaeological, and biogeochemical remains of marine vertebrates in polar sediments. These remains include well-preserved tissues such as bones, hairs and feathers, and biogeochemical markers and other proxy indicators, including deposits of guano and excrement, which can accumulate in lake and terrestrial sediments over thousands of years. Analyses of these remains have provided insight into both natural and anthropogenic impacts on marine vertebrates over millennia and have helped identify the causal agents for these impacts. Furthermore, land-based seabirds and marine mammals have been shown to play an important role as bio-vectors in polar environments as they transport significant amounts of nutrients and anthropogenic contaminants between ocean and terrestrial ecosystems.

  16. Small mammal diversity loss in response to late-Pleistocene climatic change.

    PubMed

    Blois, Jessica L; McGuire, Jenny L; Hadly, Elizabeth A

    2010-06-10

    Communities have been shaped in numerous ways by past climatic change; this process continues today. At the end of the Pleistocene epoch about 11,700 years ago, North American communities were substantially altered by the interplay of two events. The climate shifted from the cold, arid Last Glacial Maximum to the warm, mesic Holocene interglacial, causing many mammal species to shift their geographic distributions substantially. Populations were further stressed as humans arrived on the continent. The resulting megafaunal extinction event, in which 70 of the roughly 220 largest mammals in North America (32%) became extinct, has received much attention. However, responses of small mammals to events at the end of the Pleistocene have been much less studied, despite the sensitivity of these animals to current and future environmental change. Here we examine community changes in small mammals in northern California during the last 'natural' global warming event at the Pleistocene-Holocene transition and show that even though no small mammals in the local community became extinct, species losses and gains, combined with changes in abundance, caused declines in both the evenness and richness of communities. Modern mammalian communities are thus depauperate not only as a result of megafaunal extinctions at the end of the Pleistocene but also because of diversity loss among small mammals. Our results suggest that across future landscapes there will be some unanticipated effects of global change on diversity: restructuring of small mammal communities, significant loss of richness, and perhaps the rising dominance of native 'weedy' species. PMID:20495547

  17. What plant hydraulics can tell us about responses to climate-change droughts.

    PubMed

    Sperry, John S; Love, David M

    2015-07-01

    Climate change exposes vegetation to unusual drought, causing declines in productivity and increased mortality. Drought responses are hard to anticipate because canopy transpiration and diffusive conductance (G) respond to drying soil and vapor pressure deficit (D) in complex ways. A growing database of hydraulic traits, combined with a parsimonious theory of tree water transport and its regulation, may improve predictions of at-risk vegetation. The theory uses the physics of flow through soil and xylem to quantify how canopy water supply declines with drought and ceases by hydraulic failure. This transpiration 'supply function' is used to predict a water 'loss function' by assuming that stomatal regulation exploits transport capacity while avoiding failure. Supply-loss theory incorporates root distribution, hydraulic redistribution, cavitation vulnerability, and cavitation reversal. The theory efficiently defines stomatal responses to D, drying soil, and hydraulic vulnerability. Driving the theory with climate predicts drought-induced loss of plant hydraulic conductance (k), canopy G, carbon assimilation, and productivity. Data lead to the 'chronic stress hypothesis' wherein > 60% loss of k increases mortality by multiple mechanisms. Supply-loss theory predicts the climatic conditions that push vegetation over this risk threshold. The theory's simplicity and predictive power encourage testing and application in large-scale modeling. PMID:25773898

  18. Debating Climate Change

    SciTech Connect

    Malone, Elizabeth L.

    2009-11-01

    Debating Climate Change explores, both theoretically and empirically, how people argue about climate change and link to each other through various elements in their arguments. As science is a central issue in the debate, the arguments of scientists and the interpretations and responses of non-scientists are important aspects of the analysis. The book first assesses current thinking about the climate change debate and current participants in the debates surrounding the issue, as well as a brief history of various groups’ involvements. Chapters 2 and 3 distill and organize various ways of framing the climate change issue. Beginning in Chapter 4, a modified classical analysis of the elements carried in an argument is used to identify areas and degrees of disagreement and agreement. One hundred documents, drawn from a wide spectrum of sources, map the topic and debate space of the climate change issue. Five elements of each argument are distilled: the authority of the writer, the evidence presented, the formulation of the argument, the worldview presented, and the actions proposed. Then a social network analysis identifies elements of the arguments that point to potential agreements. Finally, the book suggests mechanisms by which participants in the debate can build more general agreements on elements of existing agreement.

  19. "As-If" the Climate Has Changed; What We Can Expect in Hydrologic Response

    NASA Astrophysics Data System (ADS)

    Vieux, B. E.; Looper, J.

    2015-12-01

    Predicting the effects of climate change through hydrologic modeling with hydrologic forcing representative of historic and future climates. Understanding the hydrologic impacts of various climate scenarios and pathways is accomplished with a physics-based distributed hydrologic model with historic and future precipitation and evapotranspiration inputs. Vflo is a gridded hydrologic model setup for the 71,009 sq.-km. study area, the Canadian River, extending from arid areas in eastern New Mexico, across the Texas Panhandle to Lake Eufaula in sub-humid eastern Oklahoma. This model uses merged radar and rain gauge data to generate hydrographs at gauged and ungauged locations. Vflo is calibrated to observed stream gauge data minimizing Nash-Sutcliffe error function for volume and discharge. Streamflow characteristics at ungauged locations, for both historic and future scenarios, are used to develop ecological relationships between water quality, discharge, and fish species. Testing the change in hydrologic response from future potential evapotranspiration (PET) and future precipitation is accomplished using observed rainfall. Historical rainfall is perturbed to represent future climate scenarios. Model-based simulations are used to test various scenarios comprising: 1) warmer and drier, 2) warmer and status quo precipitation, and 3) status quo PET but drier. Bias corrected and spatially down-sampled CMIP3 datasets are used to create perturbations for the latter portion of the 21st Century, 2070-2099. The change in precipitation and PET between 1970-1999 and 2070-2099 is applied to radar data from the observed period, 1995-2010. Then GCM-predicted changes in precipitation under the perturbation of historic rainfall accomplishes an important feature, i.e. preserving realistic spatial, temporal, and convective patterns of rainfall typical of the southern plains, which adds confidence to the model-based simulation of future climate impacts. Simulation of the perturbed

  20. Deep-sea ostracode species diversity: Response to late Quaternary climate change

    USGS Publications Warehouse

    Cronin, T. M.; DeMartino, D.M.; Dwyer, G.S.; Rodriguez-Lazaro, J.

    1999-01-01

    Late Quaternary ostracode assemblages from the North Atlantic Ocean were studied to establish the effect of climatic changes of the past 210,000 yr (marine oxygen isotope stages 7-1) on deep-sea benthic biodiversity and faunal composition. Two-hundred and twenty five samples from the Chain 82-24 Core 4PC (41??43'N, 32??51'W, 3427 m water depth) on the western Mid-Atlantic Ridge revealed high amplitude fluctuations in ostracode abundance and diversity coincident with orbital and suborbital scale climate oscillations measured by several paleoceanographic proxy records. During the past 210,000 yr, ostracode biodiversity as measured by species number (S) and the Shannon-Weaver index, H(S), oscillated from H(S) = 0.4 during glacial periods (marine isotope stages 6, 5d, 5b, 4, and 2) to H(S) = 1.1 during interglacial and interstadial periods (stages 7, 5e, 5c, 5a, 3 and 1). A total of 23 diversity peaks could be recognized. Eleven of these signify major periods of high diversity [H(S) > 0.8, S = 10-21] occurring every 15-20 ka. Twelve were minor peaks which may represent millennial-scale diversity oscillations. The composition of ostracode assemblages varies with Krithe-dominated assemblages characterizing glacial intervals, and Argilloecia-Cytheropteron characterizing deglacials, and trachyleberid genera (Poseidonamicus, Echinocythereis, Henryhowella, Oxycythereis) abundant during interglacials. Diversity and faunal composition changes can be matched to independent deep-sea paleoceanographic tracers such as benthic foraminiferal carbon isotopes, Krithe trace elements (Mg/Ca ratios), and to North Atlantic region climate records such as Greenland ice cores. When interpreted in light of ostracode species' ecology, these faunal and diversity patterns provide evidence that deep-sea benthic ecosystems experience significant reorganization in response to climate changes over orbital to millennial timescales.

  1. Using Rapid-Response Scenario-Building Methodology for Climate Change Adaptation Planning

    NASA Astrophysics Data System (ADS)

    Ludwig, K. A.; Stoepler, T. M.; Schuster, R.

    2015-12-01

    Rapid-response scenario-building methodology can be modified to develop scenarios for slow-onset disasters associated with climate change such as drought. Results of a collaboration between the Department of the Interior (DOI) Strategic Sciences Group (SSG) and the Southwest Colorado Social-Ecological Climate Resilience Project are presented in which SSG scenario-building methods were revised and applied to climate change adaptation planning in Colorado's Gunnison Basin, United States. The SSG provides the DOI with the capacity to rapidly assemble multidisciplinary teams of experts to develop scenarios of the potential environmental, social, and economic cascading consequences of environmental crises, and to analyze these chains to determine actionable intervention points. By design, the SSG responds to acute events of a relatively defined duration. As a capacity-building exercise, the SSG explored how its scenario-building methodology could be applied to outlining the cascading consequences of slow-onset events related to climate change. SSG staff facilitated two workshops to analyze the impacts of drought, wildfire, and insect outbreak in the sagebrush and spruce-fir ecosystems. Participants included local land managers, natural and social scientists, ranchers, and other stakeholders. Key findings were: 1) scenario framing must be adjusted to accommodate the multiple, synergistic components and longer time frames of slow-onset events; 2) the development of slow-onset event scenarios is likely influenced by participants having had more time to consider potential consequences, relative to acute events; 3) participants who are from the affected area may have a more vested interest in the outcome and/or may be able to directly implement interventions.

  2. Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change

    USGS Publications Warehouse

    Person, M.; Roy, P.; Wright, H.; Gutowski, W., Jr.; Ito, E.; Winter, T.; Rosenberry, D.; Cohen, D.

    2007-01-01

    In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the Crow Wing Watershed, Upper Mississippi Basin in north central Minnesota. The model was first calibrated to a 50 yr historical record of average annual surface-water discharge, monthly groundwater levels, and lake-level fluctuations. The model was able to reproduce reasonably well long-term historical records (1949-1999) of water-table and lake-level fluctuations across the watershed as well as stream discharge near the watershed outlet. The calibrated model was then used to reproduce paleogroundwater and lake levels using climate reconstructions based on pollen-transfer functions from Williams Lake just outside the watershed. Computed declines in mid-Holocene lake levels for two lakes at opposite ends of the watershed were between 6 and 18 m. Simulated streamflow near the outlet of the watershed decreased to 70% of modern average annual discharge after ???200 yr. The area covered by wetlands for the entire watershed was reduced by ???16%. The mid-Holocene hydrologic changes indicated by these model results and corroborated by several lake-core records across the Crow Wing Watershed may serve as a useful proxy of the hydrologic response to future warm, dry climatic forecasts (ca. 2050) made by some atmospheric general-circulation models for the glaciated Midwestern United States. ?? 2007 Geological Society of America.

  3. Modeling agricultural commodity prices and volatility in response to anticipated climate change

    NASA Astrophysics Data System (ADS)

    Lobell, D. B.; Tran, N.; Welch, J.; Roberts, M.; Schlenker, W.

    2012-12-01

    Food prices have shown a positive trend in the past decade, with episodes of rapid increases in 2008 and 2011. These increases pose a threat to food security in many regions of the world, where the poor are generally net consumers of food, and are also thought to increase risks of social and political unrest. The role of global warming in these price reversals have been debated, but little quantitative work has been done. A particular challenge in modeling these effects is that they require understanding links between climate and food supply, as well as between food supply and prices. Here we combine the anticipated effects of climate change on yield levels and volatility with an empirical competitive storage model to examine how expected climate change might affect prices and social welfare in the international food commodity market. We show that price level and volatility do increase over time in response to decreasing yield, and increasing yield variability. Land supply and storage demand both increase, but production and consumption continue to fall leading to a decrease in consumer surplus, and a corresponding though smaller increase in producer surplus.

  4. Responses of wind erosion to climate-induced vegetation changes on the Colorado Plateau

    PubMed Central

    Munson, Seth M.; Belnap, Jayne; Okin, Gregory S.

    2011-01-01

    Projected increases in aridity throughout the southwestern United States due to anthropogenic climate change will likely cause reductions in perennial vegetation cover, which leaves soil surfaces exposed to erosion. Accelerated rates of dust emission from wind erosion have large implications for ecosystems and human well-being, yet there is poor understanding of the sources and magnitude of dust emission in a hotter and drier climate. Here we use a two-stage approach to compare the susceptibility of grasslands and three different shrublands to wind erosion on the Colorado Plateau and demonstrate how climate can indirectly moderate the magnitude of aeolian sediment flux through different responses of dominant plants in these communities. First, using results from 20 y of vegetation monitoring, we found perennial grass cover in grasslands declined with increasing mean annual temperature in the previous year, whereas shrub cover in shrublands either showed no change or declined as temperature increased, depending on the species. Second, we used these vegetation monitoring results and measurements of soil stability as inputs into a field-validated wind erosion model and found that declines in perennial vegetation cover coupled with disturbance to biological soil crust resulted in an exponential increase in modeled aeolian sediment flux. Thus the effects of increased temperature on perennial plant cover and the correlation of declining plant cover with increased aeolian flux strongly suggest that sustained drought conditions across the southwest will accelerate the likelihood of dust production in the future on disturbed soil surfaces. PMID:21368143

  5. Responses of wind erosion to climate-induced vegetation changes on the Colorado Plateau

    USGS Publications Warehouse

    Munson, S.M.; Belnap, J.; Okin, G.S.

    2011-01-01

    Projected increases in aridity throughout the southwestern United States due to anthropogenic climate change will likely cause reductions in perennial vegetation cover, which leaves soil surfaces exposed to erosion. Accelerated rates of dust emission from wind erosion have large implications for ecosystems and human well-being, yet there is poor understanding of the sources and magnitude of dust emission in a hotter and drier climate. Here we use a two-stage approach to compare the susceptibility of grasslands and three different shrublands to wind erosion on the Colorado Plateau and demonstrate how climate can indirectly moderate the magnitude of aeolian sediment flux through different responses of dominant plants in these communities. First, using results from 20 y of vegetation monitoring, we found perennial grass cover in grasslands declined with increasing mean annual temperature in the previous year, whereas shrub cover in shrublands either showed no change or declined as temperature increased, depending on the species. Second, we used these vegetation monitoring results and measurements of soil stability as inputs into a field-validated wind erosion model and found that declines in perennial vegetation cover coupled with disturbance to biological soil crust resulted in an exponential increase in modeled aeolian sediment flux. Thus the effects of increased temperature on perennial plant cover and the correlation of declining plant cover with increased aeolian flux strongly suggest that sustained drought conditions across the southwest will accelerate the likelihood of dust production in the future on disturbed soil surfaces.

  6. Morphological and dietary responses of chipmunks to a century of climate change.

    PubMed

    Walsh, Rachel E; Aprígio Assis, Ana Paula; Patton, James L; Marroig, Gabriel; Dawson, Todd E; Lacey, Eileen A

    2016-09-01

    Predicting how individual taxa will respond to climatic change is challenging, in part because the impacts of environmental conditions can vary markedly, even among closely related species. Studies of chipmunks (Tamias spp.) in Yosemite National Park provide an important opportunity to explore the reasons for this variation in response. While the alpine chipmunk (T. alpinus) has undergone a significant elevational range contraction over the past century, the congeneric and partially sympatric lodgepole chipmunk (T. speciosus) has not experienced an elevational range shift during this period. As a first step toward identifying the factors underlying this difference in response, we examined evidence for dietary changes and changes in cranial morphology in these species over the past century. Stable isotope analyses of fur samples from modern and historical museum specimens of these species collected at the same localities indicated that signatures of dietary change were more pronounced in T. alpinus, although diet breadth did not differ consistently between the study species. Morphometric analyses of crania from these specimens revealed significant changes in cranial shape for T. alpinus, with less pronounced changes in shape for T. speciosus; evidence of selection on skull morphology was detected for T. alpinus, but not for T. speciosus. These results are consistent with growing evidence that T. alpinus is generally more responsive to environmental change than T. speciosus, but emphasize the complex and often geographically variable nature of such responses. Accordingly, future studies that make use of the taxonomically and spatially integrative approach employed here may prove particularly informative regarding relationships between environmental conditions, range changes, and patterns of phenotypic variation. PMID:26732228

  7. Modeling responses of large-river fish populations to global climate change through downscaling and incorporation of predictive uncertainty

    USGS Publications Warehouse

    Wildhaber, Mark L.; Wikle, Christopher K.; Anderson, Christopher J.; Franz, Kristie J.; Moran, Edward H.; Dey, Rima

    2012-01-01

    Climate change operates over a broad range of spatial and temporal scales. Understanding its effects on ecosystems requires multi-scale models. For understanding effects on fish populations of riverine ecosystems, climate predicted by coarse-resolution Global Climate Models must be downscaled to Regional Climate Models to watersheds to river hydrology to population response. An additional challenge is quantifying sources of uncertainty given the highly nonlinear nature of interactions between climate variables and community level processes. We present a modeling approach for understanding and accomodating uncertainty by applying multi-scale climate models and a hierarchical Bayesian modeling framework to Midwest fish population dynamics and by linking models for system components together by formal rules of probability. The proposed hierarchical modeling approach will account for sources of uncertainty in forecasts of community or population response. The goal is to evaluate the potential distributional changes in an ecological system, given distributional changes implied by a series of linked climate and system models under various emissions/use scenarios. This understanding will aid evaluation of management options for coping with global climate change. In our initial analyses, we found that predicted pallid sturgeon population responses were dependent on the climate scenario considered.

  8. Evaluating the Contribution of Natural Variability and Climate Model Response to Uncertainty in Projections of Climate Change Impacts on U.S. Air Quality

    EPA Science Inventory

    We examine the effects of internal variability and model response in projections of climate impacts on U.S. ground-level ozone across the 21st century using integrated global system modeling and global atmospheric chemistry simulations. The impact of climate change on air polluti...

  9. Deciduous forest responses to temperature, precipitation, and drought imply complex climate change impacts.

    PubMed

    Xie, Yingying; Wang, Xiaojing; Silander, John A

    2015-11-01

    Changes in spring and autumn phenology of temperate plants in recent decades have become iconic bio-indicators of rapid climate change. These changes have substantial ecological and economic impacts. However, autumn phenology remains surprisingly little studied. Although the effects of unfavorable environmental conditions (e.g., frost, heat, wetness, and drought) on autumn phenology have been observed for over 60 y, how these factors interact to influence autumn phenological events remain poorly understood. Using remotely sensed phenology data from 2001 to 2012, this study identified and quantified significant effects of a suite of environmental factors on the timing of fall dormancy of deciduous forest communities in New England, United States. Cold, frost, and wet conditions, and high heat-stress tended to induce earlier dormancy of deciduous forests, whereas moderate heat- and drought-stress delayed dormancy. Deciduous forests in two eco-regions showed contrasting, nonlinear responses to variation in these explanatory factors. Based on future climate projection over two periods (2041-2050 and 2090-2099), later dormancy dates were predicted in northern areas. However, in coastal areas earlier dormancy dates were predicted. Our models suggest that besides warming in climate change, changes in frost and moisture conditions as well as extreme weather events (e.g., drought- and heat-stress, and flooding), should also be considered in future predictions of autumn phenology in temperate deciduous forests. This study improves our understanding of how multiple environmental variables interact to affect autumn phenology in temperate deciduous forest ecosystems, and points the way to building more mechanistic and predictive models. PMID:26483475

  10. Deciduous forest responses to temperature, precipitation, and drought imply complex climate change impacts

    PubMed Central

    Xie, Yingying; Wang, Xiaojing; Silander, John A.

    2015-01-01

    Changes in spring and autumn phenology of temperate plants in recent decades have become iconic bio-indicators of rapid climate change. These changes have substantial ecological and economic impacts. However, autumn phenology remains surprisingly little studied. Although the effects of unfavorable environmental conditions (e.g., frost, heat, wetness, and drought) on autumn phenology have been observed for over 60 y, how these factors interact to influence autumn phenological events remain poorly understood. Using remotely sensed phenology data from 2001 to 2012, this study identified and quantified significant effects of a suite of environmental factors on the timing of fall dormancy of deciduous forest communities in New England, United States. Cold, frost, and wet conditions, and high heat-stress tended to induce earlier dormancy of deciduous forests, whereas moderate heat- and drought-stress delayed dormancy. Deciduous forests in two eco-regions showed contrasting, nonlinear responses to variation in these explanatory factors. Based on future climate projection over two periods (2041–2050 and 2090–2099), later dormancy dates were predicted in northern areas. However, in coastal areas earlier dormancy dates were predicted. Our models suggest that besides warming in climate change, changes in frost and moisture conditions as well as extreme weather events (e.g., drought- and heat-stress, and flooding), should also be considered in future predictions of autumn phenology in temperate deciduous forests. This study improves our understanding of how multiple environmental variables interact to affect autumn phenology in temperate deciduous forest ecosystems, and points the way to building more mechanistic and predictive models. PMID:26483475

  11. Evaluating the Effects of Climate Change on Summertime Ozone using a Relative Response Factor approach for Policy Makers

    EPA Science Inventory

    The impact of climate change on surface level ozone is examined through a multi-scale modeling effort that linked global and regional climate models to drive air quality model simulations. Results are quantified in terms of the Relative Response Factor (RRFE), which es...

  12. Wetlands as a Record of Climate Change and Hydrological Response in Arid Rift Settings

    NASA Astrophysics Data System (ADS)

    Ashley, G. M.

    2004-12-01

    Of all the terrestrial depositional settings, rift basins typically provide the greatest accommodation space, and consequently have some of the longest records of continental sedimentation. Lake deposits were the only rift component studied for records of long-term climatic change and for testing hypotheses of orbital forcing. Recently, the continuing quest for the paleontological and cultural records of human origins entombed in the sedimentary rocks of the East African Rift System raised questions concerning hydrologic and biologic response to climatic change. Additional issues are the impact of climate on paleolandscapes and the environmental stresses that might have affected human evolution. Other important indicators of rift hydrology, such as springs and wetlands are now emerging as viable records of climate change. Rift valley basins are shallow, hydrologically closed systems that are responsive to shifts in climate, and specifically sensitive to changes in the hydrologic budget (P-ET). Long term wet-dry cycles in the low latitudes are thought to be astronomically controlled, i.e. Milankovitch precession cycles (19-23 ka). In the tropics, precipitation (P) varies with changes in solar insolation which fluctuates <8-10 % over a cycle. Stronger insolation drives stronger summer monsoon maxima increasing P. Mean annual temperatures are high, but evapo-transpiration, ET (~ 2500 mm/yr) varies little. Consequently, during wetter periods regional groundwater reservoirs enlarge, the water table rises and springs and wetlands increase in number and in size compared to drier periods. Lake levels are known to fluctuate in response to change in hydrologic budget and wetlands appear to respond similarly. Springs and groundwater-fed wetlands are common, however the sources and sustainability of water or what geologic factors lead to the formation and longevity of wetlands is not well established. It appears that rainfall is trapped on topographic highs (rift fault blocks

  13. Identifying the main drivers of soil carbon response to climate change in arctic and boreal Alaska.

    NASA Astrophysics Data System (ADS)

    Genet, H.; McGuire, A. D.; He, Y.; Johnson, K.; Wylie, B. K.; Pastick, N. J.; Zhuang, Q.; Zhu, Z.

    2015-12-01

    Boreal and arctic regions represent the largest reservoir of carbon among terrestrial biomes. Most of this carbon is stored deep in the soil in permafrost where frozen organic matter is protected from decomposition. The vulnerability of soil carbon stocks to a changing climate in high latitudes depends on a number of physical and ecological processes. The importance of these processes in controlling the dynamics of soil carbon stocks vary across regions because of variability in vegetation composition, drainage condition, and permafrost characteristics. To better understand the main drivers of the vulnerability of soil carbon stocks to climate change in Alaska, we ran a process-based ecosystem model, the Terrestrial Ecosystem Model. This model explicitly simulates interactions between the carbon cycle and permafrost dynamics and was coupled with a disturbance model and a model of biogenic methane dynamics to assess historical and projected soil carbon dynamics in Alaska, from 1950 to 2100. The uncertainties related to climate, fire regime and atmospheric CO2projections on soil carbon dynamics were quantified by running simulations using climate projections from 2 global circulation models, 3 fossil fuel emission scenarios and 3 alternative fire management scenarios. During the historical period [1950-2009], soil carbon stocks increased by 4.7 TgC/yr in Alaska. Soil carbon stocks decreased in boreal Alaska due to substantial fire activity in the early 2000's. This loss was offset by carbon accumulation in the arctic. Changes in soil carbon stocks from 2010 to 2099 ranged from 8.9 to 25.6 TgC/yr, depending on the climate projections. Soil carbon accumulation was slower in lowlands than in uplands and slower in the boreal than in the arctic regions because of the negative effect of fire activity on soil carbon stocks. Tundra ecosystems were more vulnerable to carbon loss from fire than forest ecosystems because of a lower productivity. As a result, the increase in

  14. How Do Various Maize Crop Models Vary in Their Responses to Climate Change Factors?

    NASA Technical Reports Server (NTRS)

    Bassu, Simona; Brisson, Nadine; Grassini, Patricio; Durand, Jean-Louis; Boote, Kenneth; Lizaso, Jon; Jones, James W.; Rosenzweig, Cynthia; Ruane, Alex C.; Adam, Myriam; Baron, Christian; Basso, Bruno; Biernath, Christian; Boogaard, Hendrik; Conijn, Sjaak; Corbeels, Marc; Deryng, Delphine; DeSanctis, Giacomo; Gayler, Sebastian; Grassini, Patricio; Hatfield, Jerry; Hoek, Steven; Izaurralde, Cesar; Jongschaap, Raymond; Kemanian, Armen R.; Kersebaum, K. Christian

    2014-01-01

    Potential consequences of climate change on crop production can be studied using mechanistic crop simulation models. While a broad variety of maize simulation models exist, it is not known whether different models diverge on grain yield responses to changes in climatic factors, or whether they agree in their general trends related to phenology, growth, and yield. With the goal of analyzing the sensitivity of simulated yields to changes in temperature and atmospheric carbon dioxide concentrations [CO2], we present the largest maize crop model intercomparison to date, including 23 different models. These models were evaluated for four locations representing a wide range of maize production conditions in the world: Lusignan (France), Ames (USA), Rio Verde (Brazil) and Morogoro (Tanzania). While individual models differed considerably in absolute yield simulation at the four sites, an ensemble of a minimum number of models was able to simulate absolute yields accurately at the four sites even with low data for calibration, thus suggesting that using an ensemble of models has merit. Temperature increase had strong negative influence on modeled yield response of roughly -0.5 Mg ha(sup 1) per degC. Doubling [CO2] from 360 to 720 lmol mol 1 increased grain yield by 7.5% on average across models and the sites. That would therefore make temperature the main factor altering maize yields at the end of this century. Furthermore, there was a large uncertainty in the yield response to [CO2] among models. Model responses to temperature and [CO2] did not differ whether models were simulated with low calibration information or, simulated with high level of calibration information.

  15. Modeling Sphagnum moisture stress in response to 21st century climate change using dynamic peat properties

    NASA Astrophysics Data System (ADS)

    Moore, P.; Kettridge, N.; Morris, P. J.; Waddington, J. M.

    2013-12-01

    Sphagnum is associated with wet habitats such as northern peatlands, which may be vulnerable to enhanced 21st century drought due to climate change. We adapted a physically based, 1.5-dimensional (vertical with horizontal interaction in the saturated zone) water-balance model to investigate the role of topographic position and depth-dependence of hydrophysical properties on Sphagnum moisture stress response to current and projected climate conditions in a southern boreal peatland. We parameterized the peat hydrophysical properties using field and lab-based measurements from three adjacent peatlands with different average water table (WT) depths, microtopgraphic variability, and microtopographic patterning; where measurement locations were chosen to take advantage of a long-term WT manipulation that resulted from berm construction in the 1950s. WT level was shown to have a strong control on pore water pressure (ψ), and thus on Sphagnum moisture stress. As a result of the close correspondence between laboratory measured surface peat hydrophysical properties for hummocks and lawns used to parameterize our model, microtopographic position was shown to have a greater impact on Sphagnum moisture stress when using a static surface level. By incorporating a dynamic surface level based on ψ, bulk density, and differences in compressibility between microtopographical elements, Sphagnum moisture stress was shown to be reduced in lawns. The reduction in moisture stress was less than what would be expected based solely on surface adjustment due to the concomitant change in pore-size distribution, which we model based on changes in bulk density. Overall, model behavior suggests that, while ψ maintains equilibrium-profile values relative to the WT level for relatively shallow values, surface ψ becomes non-linearly related to WT level below a value of approximately -0.4 m, thus greatly increasing the likelihood of desiccation under future climate scenarios where growing season

  16. Phenological response to climate change in China: a meta-analysis.

    PubMed

    Ge, Quansheng; Wang, Huanjiong; Rutishauser, This; Dai, Junhu

    2015-01-01

    The change in the phenology of plants or animals reflects the response of living systems to climate change. Numerous studies have reported a consistent earlier spring phenophases in many parts of middle and high latitudes reflecting increasing temperatures with the exception of China. A systematic analysis of Chinese phenological response could complement the assessment of climate change impact for the whole Northern Hemisphere. Here, we analyze 1263 phenological time series (1960-2011, with 20+ years data) of 112 species extracted from 48 studies across 145 sites in China. Taxonomic groups include trees, shrubs, herbs, birds, amphibians and insects. Results demonstrate that 90.8% of the spring/summer phenophases time series show earlier trends and 69.0% of the autumn phenophases records show later trends. For spring/summer phenophases, the mean advance across all the taxonomic groups was 2.75 days decade(-1) ranging between 2.11 and 6.11 days decade(-1) for insects and amphibians, respectively. Herbs and amphibians show significantly stronger advancement than trees, shrubs and insect. The response of phenophases of different taxonomic groups in autumn is more complex: trees, shrubs, herbs and insects show a delay between 1.93 and 4.84 days decade(-1), while other groups reveal an advancement ranging from 1.10 to 2.11 days decade(-1) . For woody plants (including trees and shrubs), the stronger shifts toward earlier spring/summer were detected from the data series starting from more recent decades (1980s-2000s). The geographic factors (latitude, longitude and altitude) could only explain 9% and 3% of the overall variance in spring/summer and autumn phenological trends, respectively. The rate of change in spring/summer phenophase of woody plants (1960s-2000s) generally matches measured local warming across 49 sites in China (R=-0.33, P<0.05). PMID:24895088

  17. Climate change matters.

    PubMed

    Macpherson, Cheryl Cox

    2014-04-01

    One manifestation of climate change is the increasingly severe extreme weather that causes injury, illness and death through heat stress, air pollution, infectious disease and other means. Leading health organisations around the world are responding to the related water and food shortages and volatility of energy and agriculture prices that threaten health and health economics. Environmental and climate ethics highlight the associated challenges to human rights and distributive justice but rarely address health or encompass bioethical methods or analyses. Public health ethics and its broader umbrella, bioethics, remain relatively silent on climate change. Meanwhile global population growth creates more people who aspire to Western lifestyles and unrestrained socioeconomic growth. Fulfilling these aspirations generates more emissions; worsens climate change; and undermines virtues and values that engender appreciation of, and protections for, natural resources. Greater understanding of how virtues and values are evolving in different contexts, and the associated consequences, might nudge the individual and collective priorities that inform public policy toward embracing stewardship and responsibility for environmental resources necessary to health. Instead of neglecting climate change and related policy, public health ethics and bioethics should explore these issues; bring transparency to the tradeoffs that permit emissions to continue at current rates; and offer deeper understanding about what is at stake and what it means to live a good life in today's world. PMID:23665996

  18. The scaling law of climate change and its relevance to assessing (palaeo)biological responses

    NASA Astrophysics Data System (ADS)

    Kiessling, Wolfgang; Eichenseer, Kilian

    2014-05-01

    interglacials, are not monotonic, but punctuated by short-term cooling intervals. The fossil record tells us that biodiversity responded dramatically to ancient intervals of climate warming. We can now see that the apparently slower rates of change in some mass extinctions (Permian-Triassic, Triassic-Jurassic) were greater than today when the scaling law is considered. This reassures us that studying deep time patterns of organismic response to climate change is a worthwhile endeavor that is relevant for predicting the future. References Burrows, M. T., Schoeman, D. S., Buckley, L. B., Moore, P., Poloczanska, E. S., Brander, K. M., Brown, C., Bruno, J. F., Duarte, C. M., Halpern, B. S., Holding, J., Kappel, C. V., Kiessling, W., O'Connor, M. I., Pandolfi, J. M., Parmesan, C., Schwing, F. B., Sydeman, W. J., and Richardson, A. J.: The pace of shifting climate in marine and terrestrial ecosystems, Science, 334, 652-655, 2011. Gingerich, P. D.: Quantification and comparison of evolutionary rates, American Journal of Science, 293A, 453-478, 1993. Sadler, P. M.: Sediment accumulation rates and the completeness of stratigraphic sections, Journal of Geology, 89, 569-584, 1981. Sun, Y., Joachimski, M. M., Wignall, P. B., Yan, C., Chen, Y., Jiang, H., Wang, L., and Lai, X.: Lethally hot temperatures during the Early Triassic greenhouse, Science, 338, 366-370, 2012.

  19. Contrasting response of glacierized catchments in the Central Himalaya and the Central Andes to climate change

    NASA Astrophysics Data System (ADS)

    Ragettli, Silvan; Pellicciotti, Francesca; Immerzeel, Walter

    2015-04-01

    total melt from glaciers differ fundamentally. In the Langtang region in the Central Himalaya, the model results indicate increasing catchment runoff until mid-century and then either slowly declining or constant runoff depending on the climate scenario. In the Juncal region in the Central Andes catchment runoff starts to decline sharply after 2031-2040, so that annual river runoff may decrease by up to 60% until the end of the century. While in the Juncal region the seasonality of runoff may change dramatically, due to less snow- and glacier melt during the summer, the seasonality of runoff in the Central Himalaya will be essentially unaffected by climate change. Differences in catchment response are explained by differences in climate change projections (as precipitation is projected to increase in the Central Himalaya but to decrease in the Central Andes), but also by the differences in glacier characteristics and glacier evolution. Meltwater production of glaciers in Juncal is already on a decline under the present climate. In Langtang, in contrast, the rate of glacier area decrease at lower elevations is exceeded by the rate of additional glacier area at high elevations contributing to melt in a warming climate. As a consequence of this, annual icemelt in the Central Himalaya will reach its peak not before mid-century.

  20. Modeling wildfire and hydrologic response to global climate change using the Landlab modeling environment

    NASA Astrophysics Data System (ADS)

    Adams, J. M.; Gasparini, N. M.; Tucker, G. E.; Istanbulluoglu, E.; Hutton, E.; Hobley, D. E.; Nudurupati, S.

    2013-12-01

    Climate change presents new challenges in modeling surface processes across landscapes that are prone to wildfire. Historical recurrence intervals of wildfire and precipitation must be adapted to account for changes in climate. Warming temperatures have already been linked to shorter winters, smaller volumes of snowmelt, and lower soil moisture content, all of which can contribute to more frequent fires. As fire and precipitation distributions change, the magnitude of fluvial erosion in burned landscapes may change dramatically. Fluvial erosion driven by large precipitation events post-fire can threaten property, infrastructure and human life in the short-term, and potentially impact long-term landscape evolution. Understanding post-fire landscape response across multiple time scales can be accomplished through numerical modeling of fire and rainfall events and the resulting stream flow across a landscape. This study uses the Landlab modeling environment to explore possible fire and precipitation scenarios that could lead to significant post-fire landscape change. Landlab is a plug-and-play model that is designed to be highly flexible in order to address a wide range of scientific questions. This study links together a stochastic fire generator, stochastic storm generator, and overland flow module to explore scenarios that may cause significant flow in the one-year period following a high-severity fire. Post-fire landscapes have been observed to be particularly vulnerable to fluvial erosion during this period. The parameters in the fire and rainfall generator are varied to test whether erosion-inducing precipitation events will increase in frequency and severity as climate changes. We analyze potential scenarios in which fire and storm recurrence change with the climate. Three test cases are explored: increasing fire recurrence while holding the parameters of the precipitation distribution constant; increasing the recurrence of precipitation events while holding

  1. Public health and climate change adaptation at the federal level: one agency's response to Executive Order 13514.

    PubMed

    Hess, Jeremy J; Schramm, Paul J; Luber, George

    2014-03-01

    Climate change will likely have adverse human health effects that require federal agency involvement in adaptation activities. In 2009, President Obama issued Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance. The order required federal agencies to develop and implement climate change adaptation plans. The Centers for Disease Control and Prevention (CDC), as part of a larger Department of Health and Human Services response to climate change, is developing such plans. We provide background on Executive Orders, outline tenets of climate change adaptation, discuss public health adaptation planning at both the Department of Health and Human Services and the CDC, and outline possible future CDC efforts. We also consider how these activities may be better integrated with other adaptation activities that manage emerging health threats posed by climate change. PMID:24432931

  2. Public Health and Climate Change Adaptation at the Federal Level: One Agency’s Response to Executive Order 13514

    PubMed Central

    Schramm, Paul J.; Luber, George

    2014-01-01

    Climate change will likely have adverse human health effects that require federal agency involvement in adaptation activities. In 2009, President Obama issued Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance. The order required federal agencies to develop and implement climate change adaptation plans. The Centers for Disease Control and Prevention (CDC), as part of a larger Department of Health and Human Services response to climate change, is developing such plans. We provide background on Executive Orders, outline tenets of climate change adaptation, discuss public health adaptation planning at both the Department of Health and Human Services and the CDC, and outline possible future CDC efforts. We also consider how these activities may be better integrated with other adaptation activities that manage emerging health threats posed by climate change. PMID:24432931

  3. Detecting climate-change responses of plants and soil organic matter using isotopomers

    NASA Astrophysics Data System (ADS)

    Schleucher, Jürgen; Ehlers, Ina; Segura, Javier; Haei, Mahsa; Augusti, Angela; Köhler, Iris; Zuidema, Pieter; Nilsson, Mats; Öquist, Mats

    2015-04-01

    Responses of vegetation and soils to environmental changes will strongly influence future climate, and responses on century time scales are most important for feedbacks on the carbon cycle, climate models, prediction of crop productivity, and for adaptation to climate change. That plants respond to increasing CO2 on century time scales has been proven by changes in stomatal index, but very little is known beyond this. In soil, the complexity of soil organic matter (SOM) has hampered a sufficient understanding of the temperature sensitivity of SOM turnover. Here we present new stable isotope methodology that allows detecting shifts in metabolism on long time scales, and elucidating SOM turnover on the molecular level. Compound-specific isotope analysis measures isotope ratios of defined metabolites, but as average of the entire molecule. Here we demonstrate how much more detailed information can be obtained from analyses of intramolecular distributions of stable isotopes, so-called isotopomer abundances. As key tool, we use nuclear magnetic resonance (NMR) spectroscopy, which allows detecting isotope abundance with intramolecular resolution and without risk for isotope fractionation during analysis. Enzyme isotope fractionations create non-random isotopomer patterns in biochemical metabolites. At natural isotope abundance, these patterns continuously store metabolic information. We present a strategy how these patterns can be used as to extract signals on plant physiology, climate variables, and their interactions. Applied in retrospective analyses to herbarium samples and tree-ring series, we detect century-time-scale metabolic changes in response to increasing atmospheric CO2, with no evidence for acclimatory reactions by the plants. In trees, the increase in photosynthesis expected from increasing CO2 ("CO2 fertilization) was diminished by increasing temperatures, which resolves the discrepancy between expected increases in photosynthesis and commonly observed

  4. "My worries are rational, climate change is not": habitual ecological worrying is an adaptive response.

    PubMed

    Verplanken, Bas; Roy, Deborah

    2013-01-01

    Qualifications such as "global warming hysteria" and "energy policy schizophrenia" put forward by some climate change skeptics, usually outside the academic arena, may suggest that people who seriously worry about the environment suffer from psychological imbalance. The present study aimed to refute this thesis. While habitual worrying in general is strongly associated with psychopathological symptoms, in a survey a near-zero correlation was found between habitual ecological worrying and pathological worry. Instead, habitual ecological worrying was associated with pro-environmental attitudes and behaviors, and with a personality structure characterized by imagination and an appreciation for new ideas. The study had sufficient statistical power and measures were valid and reliable. The results confirm that those who habitually worry about the ecology are not only lacking in any psychopathology, but demonstrate a constructive and adaptive response to a serious problem. In the public domain, these findings may contribute to a more rational and less emotional debate on climate change and to the prevention of stigmatization of people who are genuinely concerned about our habitat and are prepared to do something about it ("habitual worriers are not crazy"). In the academic arena this study may contribute to environmental psychology ("habitual worrying is part of a green identity"), as well as to the literature on worry and anxiety ("habitual worrying can be a constructive response"). PMID:24023958

  5. Hydrologic response of Upper Ganga basin under changing land use and climate scenarios

    NASA Astrophysics Data System (ADS)

    Mujumdar, P.; Chawla, I.

    2013-12-01

    In the backdrop of recent devastation caused by flooding of the Ganga River in the upstream reaches of Uttarakhand region, India, it has become necessary to understand the implications of climate variability and human induced changes in landscape on the hydrology of the region. The present study assesses the effect of changing land use and climate on the hydrology of the Upper Ganga basin (UGB) using the Variable Infiltration Capacity (VIC) model. Initially, the temporal changes in land use and land cover (LULC) of the region are identified using high resolution multispectral satellite imageries from Landsat, for the years 1973, 1980, 2000 and 2011. The LULC analysis results show an increase in crop land and urban area in the region by 47% and 122% respectively from 1973 to 2011. After an initial decline in dense forest for three decades (from 14.5% in 1973 to 11.44% in 2000), a slight increase in dense forest is observed between 2000- 2011,from 11.44% to 14.8%. The scrub forest area and the barren land are observed to decline in the study region by 62% and 96% respectively since 1973. The land cover information along with meteorological data and soil data are used to drive the VIC model to investigate the impact of LULC changes on hydrological processes such as streamflow, baseflow, evapotranspiration (ET) and soil moisture in the UGB. For the simulation purpose, the basin is divided into three regions: (1) upstream, (2) midstream and (3) downstream. The VIC model is calibrated and validated for all the three regions independently at monthly time scale. The model outputs from the three regions are aggregated appropriately to generate the hydrologic response of the entire UGB. Using the calibrated model for the three regions of the UGB, sensitivity analysis is performed by generating hydrologic scenarios corresponding to different land use (LU) and climate conditions. The results from an experiment in which the climate is held constant at 1971 level and effect of

  6. Mechanisms Controlling Species Responses to Climate Change: Thermal Tolerances and Shifting Range Limits. (Invited)

    NASA Astrophysics Data System (ADS)

    Sage, R. F.; Bykova, O.; Coiner, H.

    2010-12-01

    One of the main effects of anthropogenic climate change will be widespread shifts in species distribution, with the common assumption that they will migrate to higher elevation and latitude. While this assumption is supported by migration patterns following climate warming in the past 20,000 years, it has not been rigorously evaluated in terms of physiological mechanism, despite the implication that migration in response to climate warming is controlled by some form of thermal adaptation. We have been evaluating the degree to which species range limits are controlled by physiological patterns of thermal tolerance in bioinvaders of North America. Bioinvaders presumably have few biotic controls over their distribution and thus are more likely to fully exploit their thermal niche. In cheatgrass (Bromus tectorum), the minimum lethal temperature in winter is -32C, which corresponds to the mean winter minimum temperature at its northern range limit. In red brome (Bromus rubens), the minimum lethal temperature is also near -32C, which is well below the minimum winter temperature near -20C that corresponds to its northern distribution limit. In kudzu (Pueraria lobata), the minimum lethal temperature is near -20C, which corresponds to the midwinter minimum at its northern distribution limit; however, overwintering kudzu tissues are insulated by soil and snow cover, and thus do not experience lethal temperatures at kudzu's northern range limit. These results demonstrate that some invasive species can exploit the potential range defined by their low temperature tolerance and thus can be predicted by mechanistic models to migrate to higher latitudes with moderation of winter cold. The distribution of other invaders such as kudzu and red brome are not controlled by tolerance of midwinter cold. Developing mechanistic models of their distributions, and how these might change with climate warming, will require extensive physiological study.

  7. Subalpine Species Response to Past Climate Change and Fire Activity: Are We Underestimating the Biotic Resilience?

    NASA Astrophysics Data System (ADS)

    Whitlock, C. L.; Iglesias, V.; Krause, T.

    2014-12-01

    Climate-change impacts on species distributions will be especially complex in mountain systems with steep environmental gradients and heterogeneous landscapes. In the western US, projected climate conditions include rising temperatures, decreased snowpack, and increased moisture deficits, all of which will impact species distributions at high elevations. Whitebark pine (Pinus albicaulis; WBP) is a keystone species in subalpine environments and one that is highly vulnerable to projected climate trends. In the past two decades, WBP populations dramatically declined as a result of bark beetle infestation, blister rust, high-severity fires, and drought. Species-niche modeling used to map future WPB distributions is based on the relation between present-day occurrence and bioclimatic parameters. While these models capture the realized niche, the full niche space inferred from paleo-observations appears to be much larger. To assess a broad range of bioclimatic conditions for WPB, we examined its response to past changes in climate, fire activity, and species competition. General additive modeling of pollen/charcoal data from the Greater Yellowstone area indicate that WBP reached maximum population size and distribution ~12,000 -7500 years ago and declined thereafter. Population dynamics tracked variations in summer insolation, such that WBP was most abundant when summer temperatures and fire frequency were higher than at present. Competition from lodgepole pine after ~10,000 years ago limited WBP at middle elevations. Paleoecological data indicate that the fundamental WBP niche is considerably larger than assumed, and simulations that project the demise of WBP in the next 50 years are probably too dramatic given WPB's ability to thrive under warm conditions and high fire activity in the past. Management strategies that reduce biotic competition and nonnative pathogens should help increase the future resilience of WBP and other subalpine species.

  8. Crocodilian diversity and distributional responses to climate changes over the last 100 Ma

    SciTech Connect

    Markwick, P.J. . Dept. of Geophysical Sciences)

    1993-03-01

    A database of over 1,100 fossil crocodilian localities has been compiled in order to study paleoclimatic changes since the middle Cretaceous. Trends in both genetic diversity and paleolatitudinal distribution for the crocodilians closely echo the climatic signal indicated by other paleoclimate indicators such as the sedimentary, floral and isotopic records. The global scale of the data means that the time resolution used is stage or coarser and so conclusions as to rates of change or smaller scale events are presently unresolvable. However a number of trends are apparent. During the hot-house world of the early and middle eocene both diversity and latitudinal poleward extent are high, but with the initial formation of ice sheets in the late Eocene and full glaciation by the middle Oligocene, both factors decrease rapidly. Latitudinal range and diversity recover in the Miocene reflecting the IRD (ice rafted detritus) record which suggests that the ice sheets dissipate or even disappear during this time, only to appear once more in the late Miocene-Pliocene when once again both generic diversity and poleward expansion of crocodilian ranges are diminished. The effects of preservational biases on this dataset are important, but the use of control groups shows that at periods of ice sheet development, and consequent drawdown in sea level, the loss of depositional area does not dominate the changes observed in crocodilian diversity and distributional patterns, and that any observed trends are real. The close correlation between climate change and the responses shown by crocodilian spatial distributions and generic diversity reaffirm the importance of climate in influencing biogeographic patterns.

  9. Responses to Climate Change: Exploring Organisational Learning across Internationally Networked Organisations for Development

    ERIC Educational Resources Information Center

    Boyd, Emily; Osbahr, Henny

    2010-01-01

    Drawing from the organisational learning and governance literature, this paper assesses four internationally networked governmental and non-governmental organisations in the UK addressing climate change. We analyse how those concerned understand the climate change crisis, what mechanisms are put in place to address information flows, and what…

  10. The sensitivity of global ozone predictions to dry deposition schemes and their response to climate change

    NASA Astrophysics Data System (ADS)

    Centoni, Federico; Stevenson, David; Fowler, David; Nemitz, Eiko; Coyle, Mhairi

    2015-04-01

    deposition to C3 grass over central-northern Europe, N. Asia and N. America is associated with a considerable decrease of surface ozone. Global and seasonal distributions of ozone concentrations and fluxes simulated using the revised UM-UKCA model were compared with global ozone concentration and flux data sets. Finally, results from a future climate integration for the 2090s using RCP 8.5 climate change scenario are presented. This was done in order to highlight the response of UM-UKCA simulated ozone to climate change only. Another experiment took into account a future vegetation distribution with the aim to investigate how land use changes might contribute to affect future ozone.

  11. Climate-ecosystem change off southern California: Time-dependent seabird predator-prey numerical responses

    NASA Astrophysics Data System (ADS)

    Sydeman, William J.; Thompson, Sarah Ann; Santora, Jarrod A.; Koslow, J. Anthony; Goericke, Ralf; Ohman, Mark D.

    2015-02-01

    Climate change may increase both stratification and upwelling in marine ecosystems, but these processes may affect productivity in opposing or complementary ways. For the Southern California region of the California Current Ecosystem (CCE), we hypothesized that changes in stratification and upwelling have affected marine bird populations indirectly through changes in prey availability. To test this hypothesis, we derived trends and associations between stratification and upwelling, the relative abundance of potential prey including krill and forage fish, and seabirds based on the long-term, multi-disciplinary CalCOFI/CCE-LTER program. Over the period 1987 through 2011, spring and summer seabird density (all species combined) declined by ~2% per year, mostly in the northern sector of the study region. Krill showed variable trends with two species increasing and one deceasing, resulting in community reorganization. Nearshore forage fish, dominated by northern anchovy (Engraulis mordax) as well as offshore mesopelagic species, show declines in relative abundance over this period. The unidirectional decline in springtime seabird density is largely explained by declining nearshore fish abundance in the previous season (winter). Interannual variability in seabird density, especially in the 2000s, is explained by variability in krill abundance. Changes in the numerical responses of seabirds to prey abundance correspond to a putative ecosystem shift in 1998-1999 and support aspects of optimal foraging (diet) theory. Predator-prey interactions and numerical responses clearly explain aspects of the upper trophic level patterns of change in the pelagic ecosystem off southern California.

  12. The response of debris-covered glaciers to climate change: A numerical modeling approach

    NASA Astrophysics Data System (ADS)

    Anderson, Leif S.; Anderson, Robert S.

    2016-04-01

    Debris-covered glaciers are common in rapidly-eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. Continuous debris cover can therefore reduce the mass balance gradient in the ablation zone, leading to increases in glacier length. In order to quantify feedbacks in the debris-glacier-climate system, we developed a 2D long-valley numerical glacier model that includes deposition of debris on the glacier surface, and both englacial and supraglacial debris advection. We ran 120 simulations in which a steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to new steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier. The debris flux onto the glacier surface, and the details of the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibrium-line altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to debris-free glaciers forced by the same climate. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). The model reproduces first-order relationships between debris cover, AARs, and glacier surface velocities reported from glaciers in High Asia. We also explore the response of debris-covered glaciers to increases in the equilibrium-line altitude (climate warming). We highlight the conditions required to generate a low surface velocity 'dead' ice terminal reach during a warming climate, and the associated increase of fractional glacier surface debris. We also compare our debris-covered glacier climate response results with data from glaciers in High Asia. Our model provides a quantitative, theoretical

  13. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions

    PubMed Central

    Zelikova, Tamara J; Hufbauer, Ruth A; Reed, Sasha C; Wertin, Timothy; Fettig, Christa; Belnap, Jayne

    2013-01-01

    How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming experiment at two sites in southeastern Utah, we tested this prediction over 4 years, measuring B. tectorum phenology, biomass, and reproduction. In a complimentary greenhouse study, we assessed whether changes in field B. tectorum biomass and reproductive output influence offspring performance. We found that following a wet winter and early spring, the timing of spring growth initiation, flowering, and summer senescence all advanced in warmed plots at both field sites and the shift in phenology was progressively larger with greater warming. Earlier green-up and development was associated with increases in B. tectorum biomass and reproductive output, likely due early spring growth, when soil moisture was not limiting, and a lengthened growing season. Seeds collected from plants grown in warmed plots had higher biomass and germination rates and lower mortality than seeds from ambient plots. However, in the following two dry years, we observed no differences in phenology between warmed and ambient plots. In addition, warming had a generally negative effect on B. tectorum biomass and reproduction in dry years and this negative effect was significant in the plots that received the highest warming treatment. In contrast to models that predict negative responses of B. tectorum to warmer climate on the Colorado Plateau, the effects of warming were more nuanced, relied on background climate, and differed between the two field sites. Our results highlight the importance of considering the interacting effects of temperature, precipitation, and site-specific characteristics such as soil texture, on plant demography and have direct

  14. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions

    USGS Publications Warehouse

    Zelikova, Tamara J.; Hufbauer, Ruth A.; Reed, Sasha C.; Wertin, Timothy M.; Fettig, Christa; Belnap, Jayne

    2013-01-01

    How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming experiment at two sites in southeastern Utah, we tested this prediction over 4 years, measuring B. tectorum phenology, biomass, and reproduction. In a complimentary greenhouse study, we assessed whether changes in field B. tectorum biomass and reproductive output influence offspring performance. We found that following a wet winter and early spring, the timing of spring growth initiation, flowering, and summer senescence all advanced in warmed plots at both field sites and the shift in phenology was progressively larger with greater warming. Earlier green-up and development was associated with increases in B. tectorum biomass and reproductive output, likely due early spring growth, when soil moisture was not limiting, and a lengthened growing season. Seeds collected from plants grown in warmed plots had higher biomass and germination rates and lower mortality than seeds from ambient plots. However, in the following two dry years, we observed no differences in phenology between warmed and ambient plots. In addition, warming had a generally negative effect on B. tectorum biomass and reproduction in dry years and this negative effect was significant in the plots that received the highest warming treatment. In contrast to models that predict negative responses of B. tectorum to warmer climate on the Colorado Plateau, the effects of warming were more nuanced, relied on background climate, and differed between the two field sites. Our results highlight the importance of considering the interacting effects of temperature, precipitation, and site-specific characteristics such as soil texture, on plant demography and have direct

  15. Simulating the hydrological responses to climate change of the Xiang River basin, China

    NASA Astrophysics Data System (ADS)

    Wang, Guoqing; Zhang, Jianyun; Pagano, Thomas C.; Xu, Yueping; Bao, Zhenxin; Liu, Yanli; Jin, Junliang; Liu, Cuishan; Song, Xiaomeng; Wan, Sicheng

    2016-05-01

    The responses of stream flow, actual evaporation, and soil moisture to climate change in six catchments within Xiang River basin, China, are investigated using Variable Infiltration Capacity (VIC) model. Results show that stream flows are highly correlated to precipitation while weakly correlated to temperature, which indicates precipitation governs variability of stream flow for these catchments. The VIC model performs well at simulating monthly discharge, with Nash Sutcliffe Efficiencies (NSEs) exceeding 70 % and relative errors (REs) of the volumetric fit falling in the range of ±10 % for both calibration and validation periods. The model can simulate seasonal cycles of soil moisture and actual evaporation reasonably well. Due to humid climate of the region, stream flows are more sensitive to changes in precipitation than to change in temperature, while soil moisture and actual evaporation tend to be relatively more affected by temperature. A 2 °C rise in temperature will lead to 5.62 % (4.3-7.45 %) decrease in stream flow, 6.45 % (5.8-7.02 %) increase in actual evaporation, and 5 % (4.16-5.59 %) decrease in soil moisture. A 10 % increase in precipitation will result in 14.17 % (13.44-15.70 %), 5.22 % (4.32-5.62 %), and 4.57 % (2.90-4.96 %) increases in stream flow, actual evaporation, and soil moisture, respectively.

  16. Consistent response of bird populations to climate change on two continents.

    PubMed

    Stephens, Philip A; Mason, Lucy R; Green, Rhys E; Gregory, Richard D; Sauer, John R; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H M; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemysław; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P B; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; van Strien, Arco J; van Turnhout, Chris A M; Vorisek, Petr; Willis, Stephen G

    2016-04-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends. PMID:27034371

  17. Consistent response of bird populations to climate change on two continents

    USGS Publications Warehouse

    Stephens, Philip A.; Mason, Lucy R.; Green, Rhys E.; Gregory, Richard D.; Sauer, John R.; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H.M.; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemyslaw; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P.B.; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G.; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; Van Strien, Arco; van Turnhout, Chris A.M.; Vorisek, Petr; Willis, Stephen G.

    2016-01-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

  18. AO/NAO Response to Climate Change. 2; Relative Importance of Low- and High-Latitude Temperature Changes

    NASA Technical Reports Server (NTRS)

    Rind, D.; Perlwitz, J.; Lonergan, P.; Lerner, J.

    2005-01-01

    Using a variety of GCM experiments with various versions of the GISS model, we investigate how different aspects of tropospheric climate changes affect the extratropical Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) circulation indices. The results show that low altitude changes in the extratropical latitudinal temperature gradient can have a strong impact on eddy forcing of the extratropical zonal wind, in the sense that when this latitudinal temperature gradient increases, it helps force a more negative AO/NAO phase. In addition, local conditions at high latitudes can stabilize/destabilize the atmosphere, inducing negative/positive phase changes. To the extent that there is not a large temperature change in the tropical upper troposphere (either through reduced tropical sensitivity at the surface, or limited transport of this change to high levels), the changes in the low level temperature gradient can provide the dominate influence on the extratropical circulation, so that planetary wave meridional refraction and eddy angular momentum transport changes become uncorrelated with potential vorticity transports. In particular, the climate change that produces the most positive NAO phase change would have substantial warming in the tropical upper troposphere over the Pacific Ocean, with high latitude warming in the North Atlantic. An increase in positive phase of these circulation indices is still more likely than not, but it will depend on the degree of tropical and high latitude temperature response and the transport of low level warming into the upper troposphere. These are aspects that currently differ among the models used for predicting the effects of global warning, contributing to the lack of consensus of future changes in the AO/NAO.

  19. Coupled terrestrial and aquatic regional responses to land use change and climate variability in a temperate New England watershed

    NASA Astrophysics Data System (ADS)

    Wollheim, W. M.; Samal, N. R.; Zhou, Z.; Zuidema, S.; Stewart, R. J.; Mineau, M.

    2015-12-01

    Climate change and land use interact to alter hydrology, biogeochemistry, and ecosystem function. Regional scale analyses that link terrestrial and aquatic ecosystems across spatial scales are needed to understand the mechanisms of response and tradeoffs among different ecosystem services. We coupled the terrestrial ecosystem model, PnET, with a river network model, FrAMES, to explore how terrestrial and aquatic conditions simultaneously respond to variation and changes in climate and land use. We applied the coupled model to the Merrimack R. watershed, NH/MA, USA, to understand how impacts vary at different nested basin scales. The coupled PnET-FrAMES predicts variables relevant to key ecosystem services including snow pack, runoff, woody biomass accumulation, net carbon sequestration, nitrogen runoff, discharge, conductivity, water temperature, aquatic denitrification, and nitrogen flux. We used statistically downscaled high and low emission scenarios of GCMs (GFDL CM2.1) to explore projected future responses to 2100. Some variables were more sensitive (snowpack, runoff, net carbon sequestration, water temperature) than others (woody biomass, conductivity, nitrogen concentration) to interannual climate variability. Water quality and terrestrial ecosystem responses were more sensitive to land use changes. Water quality responses are buffered in large rivers due to the dilution capacity of forested areas of the watersheds, but this dilution capacity is altered by future climate changes. Coupled terrestrial-aquatic models at regional scales using downscale climate projections will be essential for planning adaption and mitigation strategies in response to future climate and land use change.

  20. Assessing the Response of Nematode Communities to Climate Change-Driven Warming: A Microcosm Experiment.

    PubMed

    Gingold, Ruth; Moens, Tom; Rocha-Olivares, Axayácatl

    2013-01-01

    Biodiversity has diminished over the past decades with climate change being among the main responsible factors. One consequence of climate change is the increase in sea surface temperature, which, together with long exposure periods in intertidal areas, may exceed the tolerance level of benthic organisms. Benthic communities may suffer structural changes due to the loss of species or functional groups, putting ecological services at risk. In sandy beaches, free-living marine nematodes usually are the most abundant and diverse group of intertidal meiofauna, playing an important role in the benthic food web. While apparently many functionally similar nematode species co-exist temporally and spatially, experimental results on selected bacterivore species suggest no functional overlap, but rather an idiosyncratic contribution to ecosystem functioning. However, we hypothesize that functional redundancy is more likely to observe when taking into account the entire diversity of natural assemblages. We conducted a microcosm experiment with two natural communities to assess their stress response to elevated temperature. The two communities differed in diversity (high [HD] vs. low [LD]) and environmental origin (harsh vs. moderate conditions). We assessed their stress resistance to the experimental treatment in terms of species and diversity changes, and their function in terms of abundance, biomass, and trophic diversity. According to the Insurance Hypothesis, we hypothesized that the HD community would cope better with the stressful treatment due to species functional overlap, whereas the LD community functioning would benefit from species better adapted to harsh conditions. Our results indicate no evidence of functional redundancy in the studied nematofaunal communities. The species loss was more prominent and size specific in the HD; large predators and omnivores were lost, which may have important consequences for the benthic food web. Yet, we found evidence for

  1. Climate change affects the outcome of competitive interactions-an application of principal response curves.

    PubMed

    Heegaard, Einar; Vandvik, Vigdis

    2004-05-01

    It has been hypothesised that climate change may affect vegetation by changing the outcome of competitive interactions. We use a space-for-time approach to evaluate this hypothesis in the context of alpine time-of-snowmelt gradients. Principal response curves, a multivariate repeated-measurement analysis technique, are used to analyse for compositional differences in local ridge-to-snowbed gradients among 100 m altitudinal bands from 1,140 to 1,550 m a.s.l., corresponding to a temperature gradient of 2.5 degrees C (local lapse rate is 0.6 degrees C). The interaction between time-of-snowmelt and altitude is strongly significant statistically, indicating that the altitudinal gradient cannot be explained simply by the physiological responses of the species, but that there are also changes in the outcome of competitive interactions. At higher altitudes, there is a decrease in the time-of-snowmelt ranges of species which have intermediate times-of-snowmelt optima, whereas snowbed (chinophilous) species have wider time-of-snowmelt ranges. As snowbed species can survive, grow and reproduce at very early snow-free sites at high altitudes, the most likely explanation for their absence from all but the latest time-of-snowmelt habitats at lower altitudes is competitive exclusion by more vigorous lee-side species. This suggests that with future climate change snowbed species will experience, in addition to habitat fragmentation and reduced size of habitats due to increased temperature and snowmelt, an indirect effect due to competitive exclusion from late-snowmelt sites by species that have their optima outside snowbeds. PMID:15021981

  2. Diverging Plant and Ecosystem Strategies in Response to Climate Change in the High Arctic

    NASA Astrophysics Data System (ADS)

    Maseyk, K. S.; Welker, J. M.; Czimczik, C. I.; Lupascu, M.; Lett, C.; Seibt, U. H.

    2014-12-01

    Increasing summer precipitation means Arctic growing seasons are becoming wetter as well as warmer, but the effect of these coupled changes on tundra ecosystem functioning remains largely unknown. We have determined how warmer and wetter summers affect coupled carbon-water cycling in a High Arctic polar semi-desert ecosystem in NW Greenland. Measurements of ecosystem CO2 and water fluxes throughout the growing season and leaf ecophysiological traits (gas exchange, morphology, leaf chemistry) were made at a long-term climate change experiment. After 9 years of exposure to warmer (+ 4°C) and / or wetter (+ 50% precipitation) treatments, we found diverging plant strategies between the responses to warming with or without an increase in summer precipitation. Warming alone resulted in an increase in leaf nitrogen, mesophyll conductance and leaf-mass per area and higher rates of leaf-level photosynthesis, but with warming and wetting combined leaf traits remain largely unchanged. However, total leaf area increased with warming plus wetting but was unchanged with warming alone. The combined effect of these leaf trait and canopy adjustments is a decrease in ecosystem water-use efficiency (the ratio of net productivity to evapotranspiration) with warming only, but a substantial increase with combined warming and wetting. We conclude that increasing summer precipitation will alter tundra ecohydrological responses to warming; that leaf-level changes in ecophysiological traits have an upward cascading consequence for ecosystem and land surface-climate interactions; and the current relative resistance of High Arctic ecosystems to warming may mask biochemical and carbon cycling changes already underway.

  3. Main physical processes and mechanisms responsible for the observable climate changes in the 20-21st centuries

    NASA Astrophysics Data System (ADS)

    Zherebtsov, G. A.; Kovalenko, V. A.; Kirichenko, K. E.

    2015-11-01

    We discuss the issues of primary importance for understanding the nature of climate changes in the 20th century and main physical processes responsible for them. Special attention is paid to climate changes which occurred in 1943-1976 and 2000-2014. These periods exhibit the maximum increase in CO2 in the atmosphere, with virtually unchanged global temperature and its reduction in some regions. We study atmospheric and sea surface temperature effects of solar activity. The paper deals with results of the analysis of regularities and peculiarities of a tropospheric and sea surface temperature response to separate heliogeophysical disturbances as well as to long-term solar and geomagnetic activity variations. We also present results of the analysis of a change in sea surface temperature covering the time period 1854-2012 and their relation to solar activity variations. We find further evidence for the solar effect on climatic processes in the troposphere and ocean. We reveal a significant response in the major climatic characteristics, namely, surface air temperature and sea surface temperature (SST). It is established that the climatic response is characterized by significant space-time inhomogeneity, is regional and depends on the climate epoch. We discuss a role of wind stress and thermohaline circulation in the observable climate changes.

  4. Hydrochemical responses to climate change in high-elevation catchments of the Colorado Front Range. (Invited)

    NASA Astrophysics Data System (ADS)

    Williams, M. W.

    2009-12-01

    Potential climate impacts on the hydrochemistry of two seasonally snow covered catchments is evaluated using 24 years of data from the Niwot Ridge Long Term Ecological Research Site, Colorado. At the larger (220 ha), higher elevation (3570 m) GL4 catchment annual discharge did not change significantly based on nonparametric trend testing. However, October streaflow volumes and groundwater storage did increase, despite drought conditions near the end of the record in 2000-2004. In contrast, at the smaller (8 ha), lower elevation (3400 m) MART catchment, annual discharge decreased significantly over the study period with the most substantial changes in July-September. The study period was separated into "wet", "normal", and "dry" years based on the 75th and 25th quartiles of annual precipitation. Results indicate that MART is particularly sensitive to changes in precipitation with dry years exhibiting decreased snowmelt peak flows, earlier snowmelt timing, decreased annual discharge, and reduced late-season flows. GL4 was less susceptible to changes in precipitation and surprisingly late-season flow volumes (Sept.-Oct.) were not significantly different between wet, normal, and dry conditions. Surprisingly, during dry years both the concentrations and annual fluxes of Ca2+ and SO42- increased in the outflow of GL4, but not at the Martinelli catchment. These changes in hydrochemistry were particularly pronounced during the low-flow period. Streamwater chemistry in GL4 during drought years resembled that of permafrost, suggesting augmented flow during the fall due to permafrost melt. This study shows that seasonally snow covered catchments are particularly sensitive to changes in climate, but the hydrochemical response may depend on landscape characteristics.

  5. Fluvial responses to late Quaternary climate change in the Shiyang River drainage system, western China

    NASA Astrophysics Data System (ADS)

    Gao, Hongshan; Li, Zongmeng; Pan, Baotian; Liu, Fenliang; Liu, Xiaopeng

    2016-04-01

    As a drainage system located in arid western China, the Shiyang River, combined with considerable fluvial strata and landform information, provides an environmental context within which to investigate fluvial responses to late Quaternary climate change. Sedimentological analysis and optically stimulated luminescence (OSL) dating enabled us to reconstruct the processes and fluvial styles of three sedimentary sequences of the Shagou and Hongshui rivers in the Shiyang drainage system. Our results present a variety of river behaviors during the late Quaternary in these areas. In the upstream Shiyang River, Zhangjiadazhuang (ZJDZ) profile of the Shagou was dominated by aggradation and a meandering channel pattern at 10.6-4.2 ka, while a noticeable channel incision occurred at ~ 4.2 ka followed by lateral channel migration. In the downstream Shiyang River, Datugou (DTG) profile of the Hongshui was an aggrading meandering river from 39.7 to 7.2 ka while channel incision occurred at 7.2 ka. Another downstream profile, Wudunwan (WDW) of the Hongshui was also characterized by aggradation from 22.4 to 4.8 ka; however, its channel pattern shifted from braided to meandering at ~ 13 ka. A discernable downcutting event occurred at ~ 4.8 ka, followed by three channel aggradation and incision episodes prior to 1.8 ka. The last 1.8 ka has been characterized by modern channel and floodplain development. The fluvial processes and styles investigated have a close correlation with late Quaternary climate change in the Shiyang River drainage. During cold phases, the WDW reach was dominated by aggradation with a braided channel pattern. During warm phases, the rivers that we investigated were also characterized by aggradation but with meandering channel patterns. Channel incision events and changes of fluvial style occurred mainly during climate transitions.

  6. A Prototype Indicators System for U.S. Climate Changes, Impacts, Vulnerabilities, and Responses

    NASA Astrophysics Data System (ADS)

    Kenney, M. A.; Janetos, A.; Gerst, M.; Lloyd, A.; Wolfinger, J. F.; Reyes, J. J.; Anderson, S. M.; Pouyat, R. V.

    2015-12-01

    Indicators are observations or calculations that are used to systematically report or forecast social and biophysical conditions over time. When the purpose of indicators is to, in part, provide complex scientific information that is understood by non-scientists and included in decision processes, the choice of indicators requires a structured process that includes co-production among a range of actors, including scientists, decision-makers, and a range of stakeholders. Here we describe recommendations on a vision and a prototype created for an indicators system, we term the National Climate Indicators System (NCIS). The goal of the NCIS is to create a system of physical, natural, and societal indicators to communicate and inform decisions about climate changes, impacts, vulnerabilities, and responses. The process of generating the indicator system involved input from over 200 subject-matter experts. Organized into 13 teams, experts created conceptual models of their respective sectors to generate an initial recommended set of indicators. A subset of indicators, which could be immediately implemented, were prototyped for the U.S. Global Change Research Program (USGCRP) a Federal program that coordinates and supports integration of global change research across the government. USGCRP reviewed the recommendations (Kenney et al., 2014) and prototypes provided by the scientific experts, and recently launched 14 indicators as proof-of-concept in support of a sustained National Climate Assessment and to solicit feedback from the users. Social science research is currently being undertaken in order to evaluate how well the prototype indicators communicate science to non-scientists, the usability of indicator system portal by scientists and decision-makers, and the development of information visualization guidelines to improve visual communication effectiveness. The goal of such efforts would be to provide input into the development of a more comprehensive USGCRP indicator

  7. Increasing biological diversity in a dynamic vegetation model and consequences for simulated response to climate change

    NASA Astrophysics Data System (ADS)

    Keribin, R. M.; Friend, A. D.; Purves, D.; Smith, M. J.

    2013-12-01

    Vegetation, from tropical rainforests to the tundra, is the basis of the world food chain but is also a key component of the Earth system, with biophysical and biogeochemical impacts on the global climate, and Dynamic Global Vegetation Models (DGVMs) are an important integrative tool for understanding its responses to climate change. DGVMs up to now have treated only a small number of plant types representing broad divisions in vegetation worldwide (e.g. trees and grasses, broadleaf and needleleaf, deciduousness), but these categories ignore most of the variation that exists between plant species and between individuals within a species. Research in community ecology makes it clear however that these variations can affect large-scale ecosystem properties such as productivity and resilience to environmental changes. The current challenge is for DGVMs to account for fine-grained variations between plants and a few such models are being developed using newly-available plant trait databases such as the TRY database and insights from community ecology such as habitat filtering. Hybrid is an individual-based DGVM, first published in 1993, that models plant physiology in a mechanistic way. We modified Hybrid 8, the latest version of the model which uses surface physics taken from the GISS ModelE GCM, to include a mechanistic gap-model component with individual-based variation in tree wood density. This key plant trait is known to be strongly correlated with a trade-off between growth and mortality in the majority of forests worldwide, which allows for otherwise-similar individuals to have different life-history strategies. We investigate how the inclusion of continuous variation in wood density into the model affects the ecosystem's transient dynamics under climate change.

  8. Climate change and marine vertebrates.

    PubMed

    Sydeman, William J; Poloczanska, Elvira; Reed, Thomas E; Thompson, Sarah Ann

    2015-11-13

    Climate change impacts on vertebrates have consequences for marine ecosystem structures and services. We review marine fish, mammal, turtle, and seabird responses to climate change and discuss their potential for adaptation. Direct and indirect responses are demonstrated from every ocean. Because of variation in research foci, observed responses differ among taxonomic groups (redistributions for fish, phenology for seabirds). Mechanisms of change are (i) direct physiological responses and (ii) climate-mediated predator-prey interactions. Regional-scale variation in climate-demographic functions makes range-wide population dynamics challenging to predict. The nexus of metabolism relative to ecosystem productivity and food webs appears key to predicting future effects on marine vertebrates. Integration of climate, oceanographic, ecosystem, and population models that incorporate evolutionary processes is needed to prioritize the climate-related conservation needs for these species. PMID:26564847

  9. Response of Step-pool Mountain Channels to Wildfire Under Changing Climate-fire Regimes

    NASA Astrophysics Data System (ADS)

    Chin, A.; O'Dowd, A. P.; Storesund, R.; Parker, A.; Roberts-Niemann, C.

    2013-12-01

    The western U.S. is becoming more susceptible to wildfire, even though wildfires have occurred throughout history and pre-history. Warming climates leading to drier conditions have increased the occurrence of wildfires. Fire suppression policies throughout the twentieth century have also allowed fuel loads to build and increased the potential for larger and more frequent fires. These trends have growing impacts on human society, as evidenced in increasing number of structures destroyed and related costs of firefighting and resulting damages. Besides the first-order effects of wildfire, such as burned vegetation and reduced infiltration capacities, changing climate-fire regimes have significant indirect effects on hydrologic and geomorphologic responses. This contribution explores how these changes affect the stability and functioning of step-pool mountain streams in the context of landscape evolution. Step-pool systems are stable features adjusted to the prevailing flow and channel morphology, serving important functions of energy dissipation in high-energy environments. Steps and pools are also important ecologically, as they provide diverse habitats for sensitive organisms. Whereas step-pool channels are typically restructured by flows with recurrence intervals often exceeding 50 years, these flows are reached more frequently under changing climate-fire regimes. Following the Waldo Canyon Fire of June/July 2012, one of several recent wildfires that spread along the Colorado Front Range, we track the stability, destruction, and re-development of step-pool systems in two basins in Pike National Forest using terrestrial LiDAR scanning and surveys of longitudinal profiles and cross sections. We document how the first geomorphologically significant event on 1 July 2013 obliterated the step-pool structure in Williams Canyon, widened river channels and lowered channel beds by as much as one meter. Changes in ecological character accompanied the conversion of channel

  10. Changes in lake area in response to thermokarst processes and climate in Old Crow Flats, Yukon

    NASA Astrophysics Data System (ADS)

    Lantz, T. C.; Turner, K. W.

    2015-03-01

    Growing evidence indicates that lake-dominated ecosystems at high latitudes are undergoing significant hydrological changes. Research examining these changes is complicated because both thermokarst and climatic processes likely influence lake dynamics. To examine the relative impacts of these processes in permafrost landscapes, we investigated the dynamics of lake area and number in Old Crow Flats (OCF), Yukon using historical air photos and satellite imagery. Between 1951 and 2007, OCF experienced a decline of ~6000 ha in total lake area but gained 232 lakes. Close to half (49%) of the difference in lake area was driven by the rapid and persistent drainage of 38 large lakes. These catastrophic drainages were associated with new or enlarged outlet channels, resulted in the formation of numerous residual ponds, and were likely driven by thermokarst processes. Our analysis shows that catastrophic lake drainages have become more than 5 times more frequent in recent decades. These changes are likely related to the impacts of increased temperature and precipitation on thermokarst processes. Fifty-nine of the 170 intensively studied lakes showed either large bidirectional fluctuations or gradual cumulative declines. These changes affected a much smaller portion of OCF and were likely driven by interactions between increased precipitation and temperature and individual catchment characteristics. To anticipate landscape-scale changes in these systems, and assess their impact on hydrology, wildlife habitat, and carbon storage, field research is required to better characterize the mechanisms responsible for changes.

  11. An approach to consider behavioral plasticity as a source of uncertainty when forecasting species' response to climate change

    PubMed Central

    Muñoz, Antonio-Román; Márquez, Ana Luz; Real, Raimundo

    2015-01-01

    The rapid ecological shifts that are occurring due to climate change present major challenges for managers and policymakers and, therefore, are one of the main concerns for environmental modelers and evolutionary biologists. Species distribution models (SDM) are appropriate tools for assessing the relationship between species distribution and environmental conditions, so being customarily used to forecast the biogeographical response of species to climate change. A serious limitation of species distribution models when forecasting the effects of climate change is that they normally assume that species behavior and climatic tolerances will remain constant through time. In this study, we propose a new methodology, based on fuzzy logic, useful for incorporating the potential capacity of species to adapt to new conditions into species distribution models. Our results demonstrate that it is possible to include different behavioral responses of species when predicting the effects of climate change on species distribution. Favorability models offered in this study show two extremes: one considering that the species will not modify its present behavior, and another assuming that the species will take full advantage of the possibilities offered by an increase in environmental favorability. This methodology may mean a more realistic approach to the assessment of the consequences of global change on species' distribution and conservation. Overlooking the potential of species' phenotypical plasticity may under- or overestimate the predicted response of species to changes in environmental drivers and its effects on species distribution. Using this approach, we could reinforce the science behind conservation planning in the current situation of rapid climate change. PMID:26120426

  12. Sustainable forest management and impacts on forest responses to a changing climate

    NASA Astrophysics Data System (ADS)

    Stover, D. B.; Parker, G.; Riutta, T.; Capretz, R.; Murthy, I.; Haibao, R.; Bebber, D.

    2009-12-01

    Impacts from human activities at varying scales and intensities have a profound influence on forest carbon dynamics in addition to interactions with climate. As such, forest carbon stocks and fluxes are among the least well-defined elements of the global carbon cycle, and great uncertainty remains in predicting the effect of climate change on forest dynamics. In some cases, these management-climate interactions are well known, but often represent a fundamental gap in our understanding of ecosystem responses and are likely to be important in improving modeling of climate change, and in valuing forest carbon. To improve understanding of human induced forest management-climate interactions, a network of permanent study plots has been established in five sites around the world - in the US, UK, Brazil, India and China. The sites are near larger global monitoring (Smithsonian CTFS) plots to facilitate comparisons. At each site, a series of 1-ha plots have been placed in forest stands with differing management regimes and histories. Utilizing citizen scientists from HSBC bank, all trees >5 cm dbh are tagged, mapped, identified to species, and diameter is recorded within each plot. A subset of trees have dendrometer bands attached, to record seasonal growth. Dead wood and litterfall samples are taken, and microclimate is recorded with automatic sensors. Serial measurements will allow correlation of forest dynamics with weather. Although the studies are at an early stage current results indicate above-ground biomass estimates are 102-288 Mg ha-1 for intermediate and mature Liriodendron tulipifera-dominated stands in the US, respectively. In India, mature semi-natural evergreen forests biomass estimates are 192-235 Mg ha-1 while plantation and semi-natural core forests in the UK are estimated at 211-292 Mg ha-1. Successional Atlantic forests in Brazil are estimated to contain 192-235 Mg ha-1. In the US, initial results have demonstrated dramatic differences in microclimate

  13. The Response of Gas Hydrates to Past Climate Change along the West Spitsbergen Margin

    NASA Astrophysics Data System (ADS)

    Crocker, A. J.; Palike, H.; Rohling, E. J.

    2011-12-01

    During summer 2008, more than 250 plumes of methane bubbles were mapped escaping from the seabed along the West Spitsbergen Margin (Westbrook et al., 2009). The concentration of these plumes close to the predicted landward limit of the gas hydrate stability zone suggests that destabilised gas hydrate deposits may be the source of much of this methane. This could be a response to an observed warming of 1°C in the West Spitsbergen Current over the last 30 years. However, it is not yet known how long the bubble plumes have been active or whether the shallowest hydrate deposits could respond to a temperature perturbation in the overlying water column this rapidly. We present a multiproxy reconstruction of changes in the climate and oceanography of the West Spitsbergen margin over the last 40,000 years from sediment cores taken in 2008. By linking this to evidence of past methane releases from the margin, we can gain a better understanding of the response of shallow Arctic gas hydrate reserves to a temperature perturbation. This has important implications for climate prediction under future warming scenarios. Westbrook, G. K., Thatcher, K. E., Rohling, E. J., Piotrowski, A. M., Pälike, H. et al. Escape of methane gas from the seabed along the West Spitsbergen continental margin. GEOPHYSICAL RESEARCH LETTERS 36. doi:10.1029/2009GL039191 (2009).

  14. Does including physiology improve species distribution model predictions of responses to recent climate change?

    PubMed

    Buckley, Lauren B; Waaser, Stephanie A; MacLean, Heidi J; Fox, Richard

    2011-12-01

    Thermal constraints on development are often invoked to predict insect distributions. These constraints tend to be characterized in species distribution models (SDMs) by calculating development time based on a constant lower development temperature (LDT). Here, we assessed whether species-specific estimates of LDT based on laboratory experiments can improve the ability of SDMs to predict the distribution shifts of six U.K. butterflies in response to recent climate warming. We find that species-specific and constant (5 degrees C) LDT degree-day models perform similarly at predicting distributions during the period of 1970-1982. However, when the models for the 1970-1982 period are projected to predict distributions in 1995-1999 and 2000-2004, species-specific LDT degree-day models modestly outperform constant LDT degree-day models. Our results suggest that, while including species-specific physiology in correlative models may enhance predictions of species' distribution responses to climate change, more detailed models may be needed to adequately account for interspecific physiological differences. PMID:22352161

  15. Climate Change and Infectious Disease Risk in Western Europe: A Survey of Dutch Expert Opinion on Adaptation Responses and Actors

    PubMed Central

    Akin, Su-Mia; Martens, Pim; Huynen, Maud M.T.E.

    2015-01-01

    There is growing evidence of climate change affecting infectious disease risk in Western Europe. The call for effective adaptation to this challenge becomes increasingly stronger. This paper presents the results of a survey exploring Dutch expert perspectives on adaptation responses to climate change impacts on infectious disease risk in Western Europe. Additionally, the survey explores the expert sample’s prioritization of mitigation and adaptation, and expert views on the willingness and capacity of relevant actors to respond to climate change. An integrated view on the causation of infectious disease risk is employed, including multiple (climatic and non-climatic) factors. The results show that the experts consider some adaptation responses as relatively more cost-effective, like fostering interagency and community partnerships, or beneficial to health, such as outbreak investigation and response. Expert opinions converge and diverge for different adaptation responses. Regarding the prioritization of mitigation and adaptation responses expert perspectives converge towards a 50/50 budgetary allocation. The experts consider the national government/health authority as the most capable actor to respond to climate change-induced infectious disease risk. Divergence and consensus among expert opinions can influence adaptation policy processes. Further research is necessary to uncover prevailing expert perspectives and their roots, and compare these. PMID:26295247

  16. Climate Change and Infectious Disease Risk in Western Europe: A Survey of Dutch Expert Opinion on Adaptation Responses and Actors.

    PubMed

    Akin, Su-Mia; Martens, Pim; Huynen, Maud M T E

    2015-08-01

    There is growing evidence of climate change affecting infectious disease risk in Western Europe. The call for effective adaptation to this challenge becomes increasingly stronger. This paper presents the results of a survey exploring Dutch expert perspectives on adaptation responses to climate change impacts on infectious disease risk in Western Europe. Additionally, the survey explores the expert sample's prioritization of mitigation and adaptation, and expert views on the willingness and capacity of relevant actors to respond to climate change. An integrated view on the causation of infectious disease risk is employed, including multiple (climatic and non-climatic) factors. The results show that the experts consider some adaptation responses as relatively more cost-effective, like fostering interagency and community partnerships, or beneficial to health, such as outbreak investigation and response. Expert opinions converge and diverge for different adaptation responses. Regarding the prioritization of mitigation and adaptation responses expert perspectives converge towards a 50/50 budgetary allocation. The experts consider the national government/health authority as the most capable actor to respond to climate change-induced infectious disease risk. Divergence and consensus among expert opinions can influence adaptation policy processes. Further research is necessary to uncover prevailing expert perspectives and their roots, and compare these. PMID:26295247

  17. Climate Change and Health

    MedlinePlus

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Climate change and health Fact sheet Reviewed June 2016 Key ... in improved health, particularly through reduced air pollution. Climate change Over the last 50 years, human activities – particularly ...

  18. Fiddling with climate change

    NASA Astrophysics Data System (ADS)

    2012-01-01

    Composer and string musician, turned award-winning environmentalist, Aubrey Meyer tells Nature Climate Change why he is campaigning for countries to adopt his 'contraction and convergence' model of global development to avoid dangerous climate change.

  19. Projected asymmetric response of Adélie penguins to Antarctic climate change

    NASA Astrophysics Data System (ADS)

    Cimino, Megan A.; Lynch, Heather J.; Saba, Vincent S.; Oliver, Matthew J.

    2016-06-01

    The contribution of climate change to shifts in a species’ geographic distribution is a critical and often unresolved ecological question. Climate change in Antarctica is asymmetric, with cooling in parts of the continent and warming along the West Antarctic Peninsula (WAP). The Adélie penguin (Pygoscelis adeliae) is a circumpolar meso-predator exposed to the full range of Antarctic climate and is undergoing dramatic population shifts coincident with climate change. We used true presence-absence data on Adélie penguin breeding colonies to estimate past and future changes in habitat suitability during the chick-rearing period based on historic satellite observations and future climate model projections. During the contemporary period, declining Adélie penguin populations experienced more years with warm sea surface temperature compared to populations that are increasing. Based on this relationship, we project that one-third of current Adélie penguin colonies, representing ~20% of their current population, may be in decline by 2060. However, climate model projections suggest refugia may exist in continental Antarctica beyond 2099, buffering species-wide declines. Climate change impacts on penguins in the Antarctic will likely be highly site specific based on regional climate trends, and a southward contraction in the range of Adélie penguins is likely over the next century.

  20. Projected asymmetric response of Adélie penguins to Antarctic climate change.

    PubMed

    Cimino, Megan A; Lynch, Heather J; Saba, Vincent S; Oliver, Matthew J

    2016-01-01

    The contribution of climate change to shifts in a species' geographic distribution is a critical and often unresolved ecological question. Climate change in Antarctica is asymmetric, with cooling in parts of the continent and warming along the West Antarctic Peninsula (WAP). The Adélie penguin (Pygoscelis adeliae) is a circumpolar meso-predator exposed to the full range of Antarctic climate and is undergoing dramatic population shifts coincident with climate change. We used true presence-absence data on Adélie penguin breeding colonies to estimate past and future changes in habitat suitability during the chick-rearing period based on historic satellite observations and future climate model projections. During the contemporary period, declining Adélie penguin populations experienced more years with warm sea surface temperature compared to populations that are increasing. Based on this relationship, we project that one-third of current Adélie penguin colonies, representing ~20% of their current population, may be in decline by 2060. However, climate model projections suggest refugia may exist in continental Antarctica beyond 2099, buffering species-wide declines. Climate change impacts on penguins in the Antarctic will likely be highly site specific based on regional climate trends, and a southward contraction in the range of Adélie penguins is likely over the next century. PMID:27352849

  1. Projected asymmetric response of Adélie penguins to Antarctic climate change

    PubMed Central

    Cimino, Megan A.; Lynch, Heather J.; Saba, Vincent S.; Oliver, Matthew J.

    2016-01-01

    The contribution of climate change to shifts in a species’ geographic distribution is a critical and often unresolved ecological question. Climate change in Antarctica is asymmetric, with cooling in parts of the continent and warming along the West Antarctic Peninsula (WAP). The Adélie penguin (Pygoscelis adeliae) is a circumpolar meso-predator exposed to the full range of Antarctic climate and is undergoing dramatic population shifts coincident with climate change. We used true presence-absence data on Adélie penguin breeding colonies to estimate past and future changes in habitat suitability during the chick-rearing period based on historic satellite observations and future climate model projections. During the contemporary period, declining Adélie penguin populations experienced more years with warm sea surface temperature compared to populations that are increasing. Based on this relationship, we project that one-third of current Adélie penguin colonies, representing ~20% of their current population, may be in decline by 2060. However, climate model projections suggest refugia may exist in continental Antarctica beyond 2099, buffering species-wide declines. Climate change impacts on penguins in the Antarctic will likely be highly site specific based on regional climate trends, and a southward contraction in the range of Adélie penguins is likely over the next century. PMID:27352849

  2. Crop response to climate change in southern Africa: A comprehensive review

    NASA Astrophysics Data System (ADS)

    Zinyengere, Nkulumo; Crespo, Olivier; Hachigonta, Sepo

    2013-12-01

    Concern over future food security in southern Africa has led to various studies that assess the impact of climate change on crops in the region. The results vary according to applied methods and tools. This study reviewed and consolidated results from 19 recent studies which quantitatively project the impact of climate change on crops for the 21st century in southern Africa. Results were assessed according to crop modelling techniques, which included process-based, statistical and economic (Ricardian) modelling. Studies were assessed for their reporting and recommendations concerning adaptation and CO2 fertilisation. Results suggest that the aggregate impact of climate change on crops in southern Africa will be negative. Maize yields are projected to decline on average by 18%. The collective impact of climate change on all crop yields shows a median decline of - 11% and - 14% respectively under process-based and statistical methodologies. Median impacts show declining crop yields through the 21st century. No significant change in the near future, - 18% for the mid century and - 30% for late century. GCM driven Ricardian projections are highly variable. However, uniform climate scenarios project a median revenue decline. Notwithstanding the challenges of such a review; lack of data, bias towards reported methods and tools, uncertainty, scale etc., results indicate that climate change may impact southern African crops in important ways thereby making adaptation essential. Adaptation and CO2 fertilisation could potentially moderate the negative impacts of climate change. This implies a need for studies into future adaptation that consider CO2 fertilisation.

  3. Biotic Responses of Headwater Streams to Geophysical Alteration and Disturbance Related to Climate Change

    NASA Astrophysics Data System (ADS)

    Gresswell, R. E.; Sedell, E. R.; Cannon, S.; Hostetler, S. W.; Williams, J. E.; Haak, A. L.; Kershner, J. L.

    2009-12-01

    Climate change will potentially alter physical habitat availability for trout species (both native and nonnative) in the western USA, and ultimately affect population distribution and abundance in watersheds across the region. To understand the biological consequences of habitat alteration associated with climate change, we have developed models linking contemporary patterns of occurrence and abundance to geomorphic variables (e.g., aspect, elevation, and slope) and stream conditions derived from the habitat (e.g., temperature, discharge, and flood regimes). Because headwater streams may be especially susceptible to catastrophic disturbances in the form of debris flow torrents that have the potential to radically alter the physical structure of channels and sometimes extirpate local fish populations, we are focusing fine-scale spatial analyses in the high elevation systems. Risks of such disturbances increase exponentially in landscapes that have experienced recent wildfires when high-intensity precipitation or runoff events occur. Although predicting the timing, extent, and severity of future wildfires or subsequent precipitation and runoff events is difficult, it is possible to identify channels within stream networks that may be prone to debris flows. These channels can be identified using models based on characteristic storm and burn scenarios and geographic information describing topographic, soil, and vegetation characteristics. At-risk channels are being mapped throughout the stream networks within the study areas in the headwaters of the Colorado River to provide information about the potential for catastrophic population disturbance in response to variety of wildfire and post-wildfire storm scenarios.

  4. Unpredictable responses of garden snail ( Helix aspersa) populations to climate change

    NASA Astrophysics Data System (ADS)

    Bezemer, T. Martijn; Knight, Kevin J.

    2001-08-01

    We studied the impact of climate change on the population dynamics of the garden snail ( Helix aspersa) in the Ecotron controlled environment facility. The experimental series ran for three plant generations, allowing the snails to reproduce. We investigated the isolated and combined effects of elevated CO 2 (current + 200 μmol mol -1) and warming (current + 2ºC) in three consecutive runs (CO 2, Temperature and Combined). In the CO 2 Run, the number of juvenile snails recorded at the end of the experiment did not differ between ambient and elevated CO 2, whereas in the Temperature Run, fewer juveniles were found at elevated temperatures. An opposite response was observed in the Combined Run, where significantly more juveniles were found in elevated temperature and CO 2 compared to elevated CO 2 on its own. Within each run, juvenile emergence was not affected by treatments but juvenile presence was first observed about 70 days earlier in the Combined Run than in the Temperature Run. The differences in snail performance in the different runs were not correlated with differences in community structure or leaf quality measured as C:N ratios and neither with the abundance of the most preferred host plant species, Cardamine hirsuta. The abundance of this species, however, was significantly altered in all runs. The results illustrate clearly the degree of difficulty in making predictable generalisations about the consequences of climate change for certain species.

  5. Response of wheat restricted-tillering and vigorous growth traits to variables of climate change.

    PubMed

    Dias de Oliveira, Eduardo A; Siddique, Kadambot H M; Bramley, Helen; Stefanova, Katia; Palta, Jairo A

    2015-02-01

    The response of wheat to the variables of climate change includes elevated CO2, high temperature, and drought which vary according to the levels of each variable and genotype. Independently, elevated CO2, high temperature, and terminal drought affect wheat biomass and grain yield, but the interactive effects of these three variables are not well known. The aim of this study was to determine the effects of elevated CO2 when combined with high temperature and terminal drought on the high-yielding traits of restricted-tillering and vigorous growth. It was hypothesized that elevated CO2 alone, rather than combined with high temperature, ameliorates the effects of terminal drought on wheat biomass and grain yield. It was also hypothesized that wheat genotypes with more sink capacity (e.g. high-tillering capacity and leaf area) have more grain yield under combined elevated CO2, high temperature, and terminal drought. Two pairs of sister lines with contrasting tillering and vigorous growth were grown in poly-tunnels in a four-factor completely randomized split-plot design with elevated CO2 (700 µL L(-1)), high day time temperature (3 °C above ambient), and drought (induced from anthesis) in all combinations to test whether elevated CO2 ameliorates the effects of high temperature and terminal drought on biomass accumulation and grain yield. For biomass and grain yield, only main effects for climate change variables were significant. Elevated CO2 significantly increased grain yield by 24-35% in all four lines and terminal drought significantly reduced grain yield by 16-17% in all four lines, while high temperature (3 °C above the ambient) had no significant effect. A trade-off between yield components limited grain yield in lines with greater sink capacity (free-tillering lines). This response suggests that any positive response to predicted changes in climate will not overcome the limitations imposed by the trade-off in yield components. PMID:25330325

  6. Long-term Terrestrial Carbon and Water Cycle Responses to Projected Climate Change Beyond 2100

    NASA Astrophysics Data System (ADS)

    Hoffman, F. M.; Randerson, J. T.; Fu, W.; Lindsay, K. T.; Munoz, E.; Mahowald, N. M.; Bonan, G. B.

    2014-12-01

    Understanding the long-term responses of ecosystems to climate change is important for quantifying the strength of carbon-climate feedbacks and informing carbon management and energy policies. Using simulations from the Community Earth System Model version 1.0 (CESM1-BGC), we quantified the effects of increasing atmospheric CO2 and the resulting increases in temperature and changes in precipitation from 1850 to 2300 on terrestrial ecosystems. We analyzed the evolution of the global carbon and water cycles in four sets of Historical (1850-2005), Representative Concentration Pathway 8.5 (2006-2100), and Extended Concentration Pathway 8.5 (2101-2300) simulations with active land and ocean biogeochemical cycles. In the first set of simulations, the increasing atmospheric CO2 and other greenhouse gases and aerosols were radiatively coupled. In the second set, the CO2 was radiatively uncoupled; while in the third, CO2 and the other atmospheric forcing agents were radiatively uncoupled. The fourth set was radiatively coupled, but the ocean and land biogeochemistry experienced only the pre-industrial CO2 forcing. We found that carbon-climate feedbacks intensify as a consequence of weakening CO2 uptake by oceans and the terrestrial biosphere through the end of the 23rd century. We also investigated the effects of changing water availability on land uptake and biosphere productivity, and found an increase in terrestrial water storage globally as a result of intensification of the water cycle. Water cycle changes were driven by the balance between increasing temperatures, changing precipitation, melting snow and ice, thawing permafrost, and increasing leaf area and water use efficiency. Regional changes in precipitation and runoff were not consistent within latitude zones, resulting in differential effects on ecosystem productivity and fire frequency, particularly in the tropics. While tropical and mid-latitude productivity increases largely slowed or became negative at or

  7. Using Long-Term Experimental Warming To Distinguish Vegetation Responses To Warming From Other Environmental Drivers Related To Climate Change

    NASA Astrophysics Data System (ADS)

    Gould, W. A.; Welker, J. M.; Mercado-Díaz, J. A.; Anderson, A.; Menken, M.

    2010-12-01

    Long term studies of vegetation change throughout the tundra biome show increases in the height, canopy extent and dominance of vascular vegetation versus bryophytes and lichens, with mixed responses of the dominant shrub and graminoid growth forms. Increases in vascular vegetation are recorded for sites with and without measurable climatic warming over recent decades, but with other potential drivers, i.e., increased summer precipitation. Experimental warming of tundra vegetation at Toolik Lake, Alaska shows a clear increase in shrub abundance relative to graminoids, with correlated higher NDVI values, increasing canopy heights, and thaw depths. Responses were similar between moist and dry tundra vegetation, with greater responses in moist vegetation. NDVI, with its ability to distinguish shrub from graminoid vegetation, may be a tool to distinguish fine scale differences in the response of tundra vegetation to climatic change, i.e., shifting balances of shrub and graminoid relative abundances that may be related to distinct climatic change drivers.

  8. Evaluating the Contribution of Natural Variability and Climate Model Response to Uncertainty in Projections of Climate Change Impacts on U.S. Air Quality

    NASA Astrophysics Data System (ADS)

    Garcia Menendez, F.; Monier, E.; Selin, N. E.

    2014-12-01

    We examine the effects of internal variability and model response in projections of climate impacts on U.S. ground-level ozone across the 21st century using integrated global system modeling and global atmospheric chemistry simulations. The impact of climate change on air pollution has been explored by using general circulation model simulations to drive air quality models and project atmospheric pollutant concentrations. However, the uncertainties associated with climate projections and their propagation into air quality simulations must be well understood when undertaking these assessments. Here, we investigate the influence of climate uncertainty on projections of U.S. ground-level ozone beyond greenhouse gas emissions scenario by evaluating the roles of natural variability and climate sensitivity. The Community Atmosphere Model with Chemistry is used to simulate ozone concentrations and driven by meteorological fields generated through the MIT Integrated Global System Model (IGSM-CAM). Under unconstrained and stabilization greenhouse gas emissions scenarios, 30-year simulations centered around the years 2000, 2050 and 2100 are carried out using multiple initial conditions to assess the influence of internal variability on projected ozone changes. The climate penalty on U.S. air quality is estimated by fixing anthropogenic emissions of conventional air pollutants and precursors at year 2000 levels. The effect of climate model response is evaluated by perturbing climate sensitivity within the IGSM-CAM through a cloud radiative adjustment method and comparing ozone projections under climate sensitivities equal to 3.0 and 4.5˚C. In addition, we explore the propagation of these uncertainties into population-weighted pollutant concentrations and their potential impact on health impact assessments. In the ensemble simulation of 21st century climate we identify an important influence of natural variability and climate model response on ozone projections and find that

  9. Rapid Response of a Marine Mammal Species to Holocene Climate and Habitat Change

    PubMed Central

    de Bruyn, Mark; Hall, Brenda L.; Chauke, Lucas F.; Baroni, Carlo; Koch, Paul L.; Hoelzel, A. Rus

    2009-01-01

    Environmental change drives demographic and evolutionary processes that determine diversity within and among species. Tracking these processes during periods of change reveals mechanisms for the establishment of populations and provides predictive data on response to potential future impacts, including those caused by anthropogenic climate change. Here we show how a highly mobile marine species responded to the gain and loss of new breeding habitat. Southern elephant seal, Mirounga leonina, remains were found along the Victoria Land Coast (VLC) in the Ross Sea, Antarctica, 2,500 km from the nearest extant breeding site on Macquarie Island (MQ). This habitat was released after retreat of the grounded ice sheet in the Ross Sea Embayment 7,500–8,000 cal YBP, and is within the range of modern foraging excursions from the MQ colony. Using ancient mtDNA and coalescent models, we tracked the population dynamics of the now extinct VLC colony and the connectivity between this and extant breeding sites. We found a clear expansion signal in the VLC population ∼8,000 YBP, followed by directional migration away from VLC and the loss of diversity at ∼1,000 YBP, when sea ice is thought to have expanded. Our data suggest that VLC seals came initially from MQ and that some returned there once the VLC habitat was lost, ∼7,000 years later. We track the founder-extinction dynamics of a population from inception to extinction in the context of Holocene climate change and present evidence that an unexpectedly diverse, differentiated breeding population was founded from a distant source population soon after habitat became available. PMID:19593366

  10. Competition-interaction landscapes for the joint response of forests to climate change.

    PubMed

    Clark, James S; Bell, David M; Kwit, Matthew C; Zhu, Kai

    2014-06-01

    The recent global increase in forest mortality episodes could not have been predicted from current vegetation models that are calibrated to regional climate data. Physiological studies show that mortality results from interactions between climate and competition at the individual scale. Models of forest response to climate do not include interactions because they are hard to estimate and require long-term observations on individual trees obtained at frequent (annual) intervals. Interactions involve multiple tree responses that can only be quantified if these responses are estimated as a joint distribution. A new approach provides estimates of climate–competition interactions in two critical ways, (i) among individuals, as a joint distribution of responses to combinations of inputs, such as resources and climate, and (ii) within individuals, due to allocation requirements that control outputs, such as demographic rates. Application to 20 years of data from climate and competition gradients shows that interactions control forest responses, and their omission from models leads to inaccurate predictions. Species most vulnerable to increasing aridity are not those that show the largest growth response to precipitation, but rather depend on interactions with the local resource environment. This first assessment of regional species vulnerability that is based on the scale at which climate operates, individual trees competing for carbon and water, supports predictions of potential savannification in the southeastern US. PMID:24932467

  11. Hearing Examines Climate Change Economics

    NASA Astrophysics Data System (ADS)

    2007-03-01

    The Intergovernmental Panel on Climate Change has released its summary report on the science of climate change and will release subsequent reports on impacts and response strategies in coming months (see Eos 88(7), 2007). With this as backdrop, attention to issues related to climate change policy has been growing, particularly within the U.S. government where House and Senate committees continue to hold hearings each week on various aspects of climate change. One of these hearings, held 28 February by the House Ways and Means Committee, focused on the economic issues related to strategies for reducing levels of greenhouse gases in the atmosphere.

  12. [Homeostatic responses of plants to modern climate change: spatial and phenological aspects].

    PubMed

    Minin, A A; Voskova, A V

    2014-01-01

    A series of dates of unfolding of the first leaves and duration of the season of vegetation in the silver birch (Betulapendula Roth. (B. verrucosa Ehrh.)), as well as the duration of flowering of the bird cherry (Padus avium), mountain ash (Sórbus aucupária), and small-leaved lime (Tilia cordata Mill.) for the period 1970-2010 in the central part of European Russia were studied in order to assess the trends. Differences in phenological responses to homogeneous climate changes in the trees of the same species from the northern and southern parts of the range were revealed. If spring events occur 3-7 days earlier in the northern part, no such effect is observed in the south. This fact can be interpreted as a manifestation of the different mechanisms of homeostasis in different populations determined by their biological characteristics (in particular, by the need to pass successfully the periods of organic rest and vegetation). PMID:25720275

  13. Bridging the Divide: Linking Genomics to Ecosystem Responses to Climate Change: Final Report

    SciTech Connect

    Smith, Melinda D.

    2014-03-15

    Over the project period, we have addressed the following objectives: 1) assess the effects of altered precipitation patterns (i.e., increased variability in growing season precipitation) on genetic diversity of the dominant C4 grass species, Andropogon gerardii, and 2) experimentally assess the impacts of extreme climatic events (heat wave, drought) on responses of the dominant C4 grasses, A. gerardii and Sorghastrum nutans, and the consequences of these response for community and ecosystem structure and function. Below is a summary of how we have addressed these objectives. Objective 1 After ten years of altered precipitation, we found the number of genotypes of A. gerardii was significantly reduced compared to the ambient precipitation treatments (Avolio et al., 2013a). Although genotype number was reduced, the remaining genotypes were less related to one another indicating that the altered precipitation treatment was selecting for increasingly dissimilar genomes (based on mean pairwise Dice distance among individuals). For the four key genotypes that displayed differential abundances depending on the precipitation treatment (G1, G4, and G11 in the altered plots and G2 in the ambient plots), we identified phenotypic differences in the field that could account for ecological sorting (Avolio & Smith, 2013a). The three altered rainfall genotypes also have very different phenotypic traits in the greenhouse in response to different soil moisture availabilities (Avolio and Smith, 2013c). Two of the genotypes that increased in abundance in the altered precipitation plots had greater allocation to root biomass (G4 and G11), while G1 allocated more biomass aboveground. These phenotypic differences among genotypes suggests that changes in genotypic structure between the altered and the ambient treatments has likely occurred via niche differentiation, driven by changes in soil moisture dynamics (reduced mean, increased variability and changes in the depth distribution of

  14. The response of runoff and sediment loading in the Apalachicola River, Florida to climate and land use land cover change

    NASA Astrophysics Data System (ADS)

    Hovenga, Paige A.; Wang, Dingbao; Medeiros, Stephen C.; Hagen, Scott C.; Alizad, Karim

    2016-05-01

    The response of runoff and sediment loading in the Apalachicola River under projected climate change scenarios and land use land cover (LULC) change is evaluated. A hydrologic model using the Soil and Water Assessment Tool was developed for the Apalachicola region to simulate daily runoff and sediment load under present (circa 2000) and future conditions (2100) to understand how parameters respond over a seasonal time frame to changes in climate, LULC, and coupled climate/LULC. The Long Ashton Research Station-Weather Generator was used to downscale temperature and precipitation from three general circulation models, each under Intergovernmental Panel on Climate Change (IPCC) carbon emission scenarios A2, A1B, and B1. Projected 2100 LULC data provided by the United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center was incorporated for each corresponding IPCC scenario. Results indicate that climate change may induce seasonal shifts to both runoff and sediment loading. Changes in LULC showed that more sediment load was associated with increased agriculture and urban areas and decreased forested regions. A nonlinear response for both runoff and sediment loading was observed by coupling climate and LULC change, suggesting that both should be incorporated into hydrologic models when studying the future conditions. The outcomes from this research can be used to better guide management practices and mitigation strategies.

  15. Temporal responses of peak citrus flowering to climate change in Iran: 1960-2010

    NASA Astrophysics Data System (ADS)

    Fitchett, Jennifer; Grab, Stefan; Thompson, Dave; Roshan, GholamReza

    2014-05-01

    Recent studies investigating floral and faunal phenological responses to climate change have highlighted the extent to which these relationships are species and location specific. This study investigates temporal responses of citrus peak flowering to climate change in the cities of Kerman, Shiraz and Gorgan, Iran. Phenological data comprise peak flowering dates of five citrus types: orange (Citrus x sinensis), tangerine (Citrus x tangerine), sweet lemon (Citrus limetta), sour lemon (Citrus x limon) and sour orange (Citrus x aurantium). These were collected daily from government heritage gardens located within each of the three cities, and archived by a private Iranian company, for the period 1960-2010. For the same period, daily Tmax, Tmin, rainfall and sunshine hour data were acquired from the Iranian Meteorological Organization. Time trend analyses were undertaken for both the phenological and meteorological data, followed by linear regression to determine the nature and extent of any relationships between these variables. We find that the mean peak flowering dates, and their long-term trends over the 51-year period, are very similar amongst the five citrus types within each city, but demonstrate significant differences between cities. Flowering date advances of 0.12-0.17d/yr are recorded for Kerman, and more rapid advances of 0.56-0.65d/yr for Shiraz. Notable progressive delays in flowering dates occur in Gorgan (0.05-0.1d/yr). The peak flowering dates of citrus in the former two cities demonstrate strong relationships with mean annual Tmin, ranging from r = 0.46-0.61 (p = 0002; p < 0.0001) for Kerman to r = 0.53-0.67 (p = 0.0386; p < 0.0001) for Shiraz, and equating to peak flowering advances of 3.15-3.39d/°C and 4.34-5.47d/°C respectively. By contrast, the strongest relationships between peak flowering dates and climate in Gorgan are with rainfall (r = 0.02-0.3, p = 0.8874-0.0528), indicating a weak phenophase response