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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

    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 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

  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. 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...

  6. 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...

  7. 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...

  8. 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

  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. 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

  11. 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.

  12. 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.

  13. 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.

  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

    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 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

  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. 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...

  18. 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…

  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. 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.

  5. 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.

  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. 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.

  16. 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

  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

    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

  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. 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...

  4. 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.

  5. 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...

  6. 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...

  7. 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)

  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. 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

  20. 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

  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

    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

  11. 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

  12. 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

  13. 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.

  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

    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

  19. 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

  20. 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

  1. 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;...

  2. 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

  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. 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

  12. 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.

  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. 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

  18. 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

  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.

    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

  3. 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.

  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, 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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

  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. 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

  1. 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

  2. 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

  3. 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.

  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. 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.

  13. 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...

  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. 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...

  18. 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

  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. 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.

  1. 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.

  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. 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

  8. 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.

  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.