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1

Extension of the PMV model to non-air-conditioned buildings in warm climates  

Microsoft Academic Search

The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV predicts. The main reason is low expectations, but a metabolic rate that is estimated too

P. Ole Fanger; Jørn Toftum

2002-01-01

2

Climate science: Pacemakers of warming  

NASA Astrophysics Data System (ADS)

In the first decades of the twentieth century, the Earth warmed rapidly. A coral-based climate proxy record of westerly winds over the equatorial Pacific suggests that wind strength and warming rate were linked, as they are today.

Brönnimann, Stefan

2015-02-01

3

The global climate of December 1992February 1993. Part I: Warm ENSO conditions continue in the tropical Pacific; California drought abates  

Microsoft Academic Search

Part I of this Seasonal Climate Summary present an analysis of the global climate during December 1992 - February 1993 (DJF). Atmospheric and oceanic indices indicate the redevelopment of mature El Nino-Southern Oscillation conditions in the tropical Pacific during DJF. This marks one of the longest periods of continuous warm episode conditions on record. Above normal sea surface temperature covered

G. D. Bell; A. N. Basist

1994-01-01

4

Provision for bearing capacity of permafrost soils in conditions of climate warming  

SciTech Connect

Results are given from numerical calculations of the change in temperature conditions of the permafrost layer and its strength properties with possible warming of the air temperature by 2-4{degrees}C in the next 60 years. The effect of these changes on the bearing capacity of permafrost soils and the associated stability of structures erected in the permafrost zone is evaluated. Measures that provide for stability of these structures by using the natural cold of the North are discussed. It is taken into account that the natural temperature of the permafrost layer changes in a meridional direction from north to south, and that, in connection with this, the sensitivity of permafrost soil to a thermal action also changes.

Vyalov, S.S.; Fotiev, S.M.; Gerasimov, A.S.; Zolotar, A.I. [Moscow State Construction Univ. (Russian Federation)

1994-05-01

5

Response of ocean ecosystems to climate warming  

Microsoft Academic Search

We examine six different coupled climate model simulations to determine the ocean biological response to climate warming between the beginning of the industrial revolution and 2050. We use vertical velocity, maximum winter mixed layer depth, and sea ice cover to define six biomes. Climate warming leads to a contraction of the highly productive marginal sea ice biome by 42 in

J. L. Sarmiento; R. Slater; R. Barber; L. Bopp; S. C. Doney; A. C. Hirst; J. Kleypas; R. Matear; U. Mikolajewicz; P. Monfray; V. Soldatov; S. A. Spall; R. Stouffer

2004-01-01

6

Warming asymmetry in climate change simulations  

Microsoft Academic Search

Climate change simulations made with coupled global climate models typically show a marked hemispheric asymmetry with more warming in the northern high lati- tudes than in the south. This asymmetry is ascribed to heat uptake by the ocean at high southern latitudes. A re- cent version of the CCCma climate model exhibits a much more symmetric warming, compared to an

G. M. Flato; G. J. Boer

2001-01-01

7

How strong is carbon cycle-climate feedback under global warming?  

E-print Network

How strong is carbon cycle-climate feedback under global warming? Haifeng Qian Advisor: Prof. Ning IPCC report, global warming was predicted under different CO2 scenarios. Under such warming conditions carbon cycle to the climate system, which means that under the global warming condition, the ecosystem

Maryland at College Park, University of

8

The global climate of December 1992-February 1993. Part I: Warm ENSO conditions continue in the tropical Pacific; California drought abates  

SciTech Connect

Part I of this Seasonal Climate Summary present an analysis of the global climate during December 1992 - February 1993 (DJF). Atmospheric and oceanic indices indicate the redevelopment of mature El Nino-Southern Oscillation conditions in the tropical Pacific during DJF. This marks one of the longest periods of continuous warm episode conditions on record. Above normal sea surface temperature covered large portions of the tropical and subtropical eastern Pacific during the period. In the extratropics, one prominent feature during the season was extremely heavy precipitation totals over California and the southwestern US. This precipitation was associated with enhanced southwesterly flow, above normal cyclone activity, and enhanced transport of low-level moisture into the region from the subtropical North Pacific. A second prominent feature was a strong positive phase of the North Atlantic Oscillation.

Bell, G.D.; Basist, A.N. [Climate Analysis Center, Washington, DC (United States)] [Climate Analysis Center, Washington, DC (United States)

1994-10-01

9

Effects of climate warming, North Atlantic Oscillation, and El Niño-Southern Oscillation on thermal conditions and plankton dynamics in northern hemispheric lakes.  

PubMed

Impacts of climate warming on freshwater ecosystems have been documented recently for a variety of sites around the globe. Here we provide a review of studies that report long-term (multidecadal) effects of warming trends on thermal properties and plankton dynamics in northern hemispheric lakes. We show that higher lake temperatures, shorter periods with ice cover, and shorter stagnation periods were common trends for lakes across the hemisphere in response to the warmer conditions. Only for shallow dimictic lakes was it observed that deep-water temperatures decreased. Moreover, it became evident that phytoplankton dynamics and primary productivity altered in conjunction with changes in lake physics. Algal spring blooms developed early and were more pronounced in several European lakes after mild winters with short ice cover periods, and primary productivity increased in North American lakes. Effects of elevated temperatures on zooplankton communities were seen in an early development of various species and groups, as is documented for cladocerans, copepods, and rotifers in European lakes. Furthermore, thermophile species reached higher abundance in warmer years. Obviously, the nature of responses is species specific, and depends on the detailed seasonal patterning of warming. Complex responses such as effects propagating across trophic levels are likely, indicating that observed climate-ecosystem relationships are not generally applicable. Nonetheless, the picture emerges that climate-driven changes in freshwater ecosystems may be synchronised to a certain extent among lakes even over great distances if climatic influences are not masked by anthropogenic impacts or differences in lake morphology. Macro-scale climatic fluctuations--such as the North Atlantic Oscillation or the El Niño-Southern Oscillation--were identified as the most important candidates responsible for such coherence, with the former predominating in Europe and the latter in North America. We emphasise, however, that the driving mechanisms and the future behaviour of these oscillations are rather uncertain, which complicates extrapolation of observed effects into the future. Thus, it is necessary to quantify the most important climate-ecosystem relationships in models of appropriate complexity. Such models will help elucidate the multiple pathways climate affects freshwater ecosystems, and will indicate possible adverse effects of a warmer future climate. PMID:12805986

Gerten, Dieter; Adrian, Rita

2002-03-01

10

WHAT'S IN A NAME? GLOBAL WARMING VERSUS CLIMATE CHANGE  

E-print Network

WHAT'S IN A NAME? GLOBAL WARMING VERSUS CLIMATE CHANGE May 2014 #12;What's In A Name? Global Warming vs. Climate Change 1 TABLE OF CONTENTS PREFACE NATIONAL SURVEY STUDY 2: GLOBAL WARMING VS. CLIMATE CHANGE............................ 10 Is global

Haller, Gary L.

11

Design extremes in a warming climate- A global assessment of changes in antecedent conditions preceding extreme rainfall events with warming temperatures  

NASA Astrophysics Data System (ADS)

Antecedent moisture of a catchment is an important variable that influences, amongst other things, the severity of floods that occurs in a catchment. While there exist several studies that evaluate changes in extreme precipitation as well as attribute such trends to global warming, an assessment of whether or not trends exist in antecedent moisture condition prior to such extreme rain has not been conducted. In this study, antecedent precipitation index (API), a weighted sum of precipitation preceding extreme events, is used as a surrogate measure of antecedent moisture to evaluate possible trends in different regions of the world. To this end, trends in annual API for tropical and extra-tropical regions as well as for each continent across the world are estimated as follows. First, a threshold precipitation is selected to obtain, on average, five extreme precipitation per year at each observation station using daily precipitation data across the world. Second, API at each of these extreme precipitation as well as exceedance probabilities of the API are determined. Finally, trends in the exceedance probabilities of the API together with the associated uncertainty are estimated for the tropics and extra-tropics as well as each continent of the world using the Thiessen polygon method. Estimation of trends based on exceedance probabilities of the API, rather than the API itself, allows to objectively compare trends across different observation stations and regions. We found a significant increasing API trend in Africa, Europe and Australia as well as Extra-tropics regions whereas significant decreasing trend being obtained in South America and the Tropics. The analysis in North America and Asia does not indicate any significant trend. Overall, this study reveals that significant trends exist in the antecedent moisture in many parts of the world, which needs be considered in the estimation of design flood as well as planning and design of hydraulic structures.

Sharma, Ashish; Woldemeskel, Fitsum

2014-05-01

12

Issues of the Global Warming and Climate Change Simulations  

Microsoft Academic Search

This paper discusses the issues of global warming and climate change simulations as a task of the Center for Climate System Research in the COE21 Project. The issues cover better simulation of various feedback processes among atmosphere, ocean, land, and cryosphere, and realistic simulation of physical and chemical condition of the system. One of the goals of the COE21 Project

Teruyuki Nakajima; Masahide Kimoto; Ayako Abe; Hiroyasu Hasumi

13

State-dependent climate sensitivity in past warm climates and its implications for future climate projections  

PubMed Central

Projections of future climate depend critically on refined estimates of climate sensitivity. Recent progress in temperature proxies dramatically increases the magnitude of warming reconstructed from early Paleogene greenhouse climates and demands a close examination of the forcing and feedback mechanisms that maintained this warmth and the broad dynamic range that these paleoclimate records attest to. Here, we show that several complementary resolutions to these questions are possible in the context of model simulations using modern and early Paleogene configurations. We find that (i) changes in boundary conditions representative of slow “Earth system” feedbacks play an important role in maintaining elevated early Paleogene temperatures, (ii) radiative forcing by carbon dioxide deviates significantly from pure logarithmic behavior at concentrations relevant for simulation of the early Paleogene, and (iii) fast or “Charney” climate sensitivity in this model increases sharply as the climate warms. Thus, increased forcing and increased slow and fast sensitivity can all play a substantial role in maintaining early Paleogene warmth. This poses an equifinality problem: The same climate can be maintained by a different mix of these ingredients; however, at present, the mix cannot be constrained directly from climate proxy data. The implications of strongly state-dependent fast sensitivity reach far beyond the early Paleogene. The study of past warm climates may not narrow uncertainty in future climate projections in coming centuries because fast climate sensitivity may itself be state-dependent, but proxies and models are both consistent with significant increases in fast sensitivity with increasing temperature. PMID:23918397

Caballero, Rodrigo; Huber, Matthew

2013-01-01

14

GLOBAL WARMING AND CLIMATE CHANGE MITIGATION TECHNOLOGIES  

Microsoft Academic Search

This paper provides an overview of climate change issues and their related international initiatives to response the challenge of the global warming. It addresses the different technologies for the mitigation of climate changes, including energy efficiency improvement, renewable energy, and greenhouse gas capture and sequestration. It focuses on the technologies of CO2 capture and sequestration and the recent development on

Jinyue Yan

15

The global climate for June to August 1990: Drought returns to sub-Saharan West Africa and warm southern oscillation episode conditions develop in the central pacific  

SciTech Connect

Although the general monsoon circulation evolved relatively normally over most of the globe, dry conditions returned to sub-Saharan West Africa. The Northern Hemisphere summer surface temperature continued to be above normal over most land areas, but in general the anomolies were less extreme. The equatorial sea surface temperatures continued to move toward warm episode Southern Oscillation conditions in the central Pacific, but without an accompanying warming in the traditional eastern Pacific El Nino areas.

Ropelewski, C.F. (Climate Analysis Center, Washington, DC (United States)); Lamb, P.J.; Portis, D.H. (Univ. of Oklahoma, Norman, OK (United States))

1993-11-01

16

Indian Ocean warming modulates Pacific climate change  

PubMed Central

It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east–west Walker circulation) through the Pacific ocean–atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific’s could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries. PMID:23112174

Luo, Jing-Jia; Sasaki, Wataru; Masumoto, Yukio

2012-01-01

17

Projected changes of snow conditions and avalanche activity in a warming climate: the French Alps over the 2020-2050 and 2070-2100 periods  

NASA Astrophysics Data System (ADS)

Projecting changes in snow cover due to climate warming is important for many societal issues, including the adaptation of avalanche risk mitigation strategies. Efficient modelling of future snow cover requires high resolution to properly resolve the topography. Here, we introduce results obtained through statistical downscaling techniques allowing simulations of future snowpack conditions including mechanical stability estimates for the mid and late 21st century in the French Alps under three climate change scenarios. Refined statistical descriptions of snowpack characteristics are provided in comparison to a 1960-1990 reference period, including latitudinal, altitudinal and seasonal gradients. These results are then used to feed a statistical model relating avalanche activity to snow and meteorological conditions, so as to produce the first projection on annual/seasonal timescales of future natural avalanche activity based on past observations. The resulting statistical indicators are fundamental for the mountain economy in terms of anticipation of changes. Whereas precipitation is expected to remain quite stationary, temperature increase interacting with topography will constrain the evolution of snow-related variables on all considered spatio-temporal scales and will, in particular, lead to a reduction of the dry snowpack and an increase of the wet snowpack. Overall, compared to the reference period, changes are strong for the end of the 21st century, but already significant for the mid century. Changes in winter are less important than in spring, but wet-snow conditions are projected to appear at high elevations earlier in the season. At the same altitude, the southern French Alps will not be significantly more affected than the northern French Alps, which means that the snowpack will be preserved for longer in the southern massifs which are higher on average. Regarding avalanche activity, a general decrease in mean (20-30%) and interannual variability is projected. These changes are relatively strong compared to changes in snow and meteorological variables. The decrease is amplified in spring and at low altitude. In contrast, an increase in avalanche activity is expected in winter at high altitude because of conditions favourable to wet-snow avalanches earlier in the season. Comparison with the outputs of the deterministic avalanche hazard model MEPRA (Modèle Expert d'aide à la Prévision du Risque d'Avalanche) shows generally consistent results but suggests that, even if the frequency of winters with high avalanche activity is clearly projected to decrease, the decreasing trend may be less strong and smooth than suggested by the statistical analysis based on changes in snowpack characteristics and their links to avalanches observations in the past. This important point for risk assessment pleads for further work focusing on shorter timescales. Finally, the small differences between different climate change scenarios show the robustness of the predicted avalanche activity changes.

Castebrunet, H.; Eckert, N.; Giraud, G.; Durand, Y.; Morin, S.

2014-09-01

18

Stream Temperature Sensitivity to Climate Warming in California's Sierra Nevada  

NASA Astrophysics Data System (ADS)

Water temperatures influence the distribution, abundance, and health of aquatic organisms in stream ecosystems. Improving understanding of climate warming on the thermal regime of rivers will help water managers better manage instream habitat. This study assesses climate warming impacts on unregulated stream temperatures in California’s west-slope Sierra Nevada watersheds from the Feather River to the Kern River. We used unregulated hydrology to isolate climate induced changes from those of water operations and land use changes. A 21 year timeseries of weekly instream flow estimates from WEAP21, a spatially explicit rainfall-runoff model were passed to RTEMP, a simplified model based on equilibrium temperature theory, to estimate stream temperatures using net heat exchange, coarse river channel geometry, and exposure time of water to atmospheric conditions. Air temperature was uniformly increased by 2?C, 4?C, and 6?C as a sensitivity analysis to bracket the range of likely outcomes for stream temperatures. Other meteorological conditions, including precipitation, were left unchanged from historical values. Overall, stream temperatures increased by an average of 1.6?C for each 2?C rise in air temperature, and increased most at middle elevations. Thermal heterogeneity existed within and between basins (Figure 1). The high watersheds of the southern Sierra Nevada and the Feather River watershed were less vulnerable to changes in the thermal regime of rivers from climate warming. Precipitation as rainfall instead of snowfall, and low flow conditions were two characteristics that drove water temperatures dynamics with climate warming. These results suggest the thermal regime of rivers will change with climate warming. Viable coldwater habitat will shift to higher elevations and will likely be reduced in California. Understanding potential changes to stream temperatures from climate warming will affect how fish and wildlife are managed, and must be incorporated into modeling studies, restoration assessments, environmental impact statements, and licensing operations of hydropower facilities to best estimate future conditions and achieve desired outcomes. Average annual number of weeks stream temperature exceeds 24°C with incremental uniform 2°C air temperature increases

Null, S.; Viers, J. H.; Deas, M.; Tanaka, S.; Mount, J.

2010-12-01

19

Climate warming will not decrease winter mortality  

NASA Astrophysics Data System (ADS)

It is widely assumed by policymakers and health professionals that the harmful health impacts of anthropogenic climate change will be partially offset by a decline in excess winter deaths (EWDs) in temperate countries, as winters warm. Recent UK government reports state that winter warming will decrease EWDs. Over the past few decades, however, the UK and other temperate countries have simultaneously experienced better housing, improved health care, higher incomes and greater awareness of the risks of cold. The link between winter temperatures and EWDs may therefore no longer be as strong as before. Here we report on the key drivers that underlie year-to-year variations in EWDs. We found that the association of year-to-year variation in EWDs with the number of cold days in winter ( <5 °C), evident until the mid 1970s, has disappeared, leaving only the incidence of influenza-like illnesses to explain any of the year-to-year variation in EWDs in the past decade. Although EWDs evidently do exist, winter cold severity no longer predicts the numbers affected. We conclude that no evidence exists that EWDs in England and Wales will fall if winters warm with climate change. These findings have important implications for climate change health adaptation policies.

Staddon, Philip L.; Montgomery, Hugh E.; Depledge, Michael H.

2014-03-01

20

Response of ocean ecosystems to climate warming  

NASA Astrophysics Data System (ADS)

We examine six different coupled climate model simulations to determine the ocean biological response to climate warming between the beginning of the industrial revolution and 2050. We use vertical velocity, maximum winter mixed layer depth, and sea ice cover to define six biomes. Climate warming leads to a contraction of the highly productive marginal sea ice biome by 42% in the Northern Hemisphere and 17% in the Southern Hemisphere, and leads to an expansion of the low productivity permanently stratified subtropical gyre biome by 4.0% in the Northern Hemisphere and 9.4% in the Southern Hemisphere. In between these, the subpolar gyre biome expands by 16% in the Northern Hemisphere and 7% in the Southern Hemisphere, and the seasonally stratified subtropical gyre contracts by 11% in both hemispheres. The low-latitude (mostly coastal) upwelling biome area changes only modestly. Vertical stratification increases, which would be expected to decrease nutrient supply everywhere, but increase the growing season length in high latitudes. We use satellite ocean color and climatological observations to develop an empirical model for predicting chlorophyll from the physical properties of the global warming simulations. Four features stand out in the response to global warming: (1) a drop in chlorophyll in the North Pacific due primarily to retreat of the marginal sea ice biome, (2) a tendency toward an increase in chlorophyll in the North Atlantic due to a complex combination of factors, (3) an increase in chlorophyll in the Southern Ocean due primarily to the retreat of and changes at the northern boundary of the marginal sea ice zone, and (4) a tendency toward a decrease in chlorophyll adjacent to the Antarctic continent due primarily to freshening within the marginal sea ice zone. We use three different primary production algorithms to estimate the response of primary production to climate warming based on our estimated chlorophyll concentrations. The three algorithms give a global increase in primary production of 0.7% at the low end to 8.1% at the high end, with very large regional differences. The main cause of both the response to warming and the variation between algorithms is the temperature sensitivity of the primary production algorithms. We also show results for the period between the industrial revolution and 2050 and 2090.

Sarmiento, J. L.; Slater, R.; Barber, R.; Bopp, L.; Doney, S. C.; Hirst, A. C.; Kleypas, J.; Matear, R.; Mikolajewicz, U.; Monfray, P.; Soldatov, V.; Spall, S. A.; Stouffer, R.

2004-09-01

21

Evaluating the Dominant Components of Warming in Pliocene Climate Simulations  

NASA Technical Reports Server (NTRS)

The Pliocene Model Intercomparison Project (PlioMIP) is the first coordinated climate model comparison for a warmer palaeoclimate with atmospheric CO2 significantly higher than pre-industrial concentrations. The simulations of the mid-Pliocene warm period show global warming of between 1.8 and 3.6 C above pre-industrial surface air temperatures, with significant polar amplification. Here we perform energy balance calculations on all eight of the coupled ocean-atmosphere simulations within PlioMIP Experiment 2 to evaluate the causes of the increased temperatures and differences between the models. In the tropics simulated warming is dominated by greenhouse gas increases, with the cloud component of planetary albedo enhancing the warming in most of the models, but by widely varying amounts. The responses to mid-Pliocene climate forcing in the Northern Hemisphere midlatitudes are substantially different between the climate models, with the only consistent response being a warming due to increased greenhouse gases. In the high latitudes all the energy balance components become important, but the dominant warming influence comes from the clear sky albedo, only partially offset by the increases in the cooling impact of cloud albedo. This demonstrates the importance of specified ice sheet and high latitude vegetation boundary conditions and simulated sea ice and snow albedo feedbacks. The largest components in the overall uncertainty are associated with clouds in the tropics and polar clear sky albedo, particularly in sea ice regions. These simulations show that albedo feedbacks, particularly those of sea ice and ice sheets, provide the most significant enhancements to high latitude warming in the Pliocene.

Hill, D. J.; Haywood, A. M.; Lunt, D. J.; Hunter, S. J.; Bragg, F. J.; Contoux, C.; Stepanek, C.; Sohl, L.; Rosenbloom, N. A.; Chan, W.-L.; Kamae, Y.; Zhang, Z.; Abe-Ouchi, A.; Chandler, M. A.; Jost, A.; Lohmann, G.; Otto-Bliesner, B. L.; Ramstein, G.; Ueda, H.

2014-01-01

22

Divergence of reproductive phenology under climate warming  

PubMed Central

Because the flowering and fruiting phenology of plants is sensitive to environmental cues such as temperature and moisture, climate change is likely to alter community-level patterns of reproductive phenology. Here we report a previously unreported phenomenon: experimental warming advanced flowering and fruiting phenology for species that began to flower before the peak of summer heat but delayed reproduction in species that started flowering after the peak temperature in a tallgrass prairie in North America. The warming-induced divergence of flowering and fruiting toward the two ends of the growing season resulted in a gap in the staggered progression of flowering and fruiting in the community during the middle of the season. A double precipitation treatment did not significantly affect flowering and fruiting phenology. Variation among species in the direction and magnitude of their response to warming caused compression and expansion of the reproductive periods of different species, changed the amount of overlap between the reproductive phases, and created possibilities for an altered selective environment to reshape communities in a future warmed world. PMID:17182748

Sherry, Rebecca A.; Zhou, Xuhui; Gu, Shiliang; Arnone, John A.; Schimel, David S.; Verburg, Paul S.; Wallace, Linda L.; Luo, Yiqi

2007-01-01

23

Adapting California's water system to warm vs. dry climates  

E-print Network

was developed from downscaled effects of the GFDL CM2.1 (A2 emissions scenario) global climate model for a 30 climate (wet winters and warm, dry summers), California's urban and agricultural water supply dependsAdapting California's water system to warm vs. dry climates Christina R. Connell-Buck & Josué

Pasternack, Gregory B.

24

GLOBAL WARMING, CLIMATE CHANGE AND HUMAN PSYCHOLOGY 1  

Microsoft Academic Search

This chapter considers psychological aspects of global warming and climate change. It begins with a brief consideration of the public and political recognition of global warming and climate change as significant environmental issues. The chapter then turns to a review of the scientific evidence of the causes and consequences of climate change, and some of the issues in psychology that

Taciano L. Milfont

25

Lagging adaptation to warming climate in Arabidopsis thaliana  

PubMed Central

If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer climates will outperform natives and may provide genetic potential for evolutionary rescue. We tested for lagging adaptation to warming climate using banked seeds of the annual weed Arabidopsis thaliana in common garden experiments in four sites across the species’ native European range: Valencia, Spain; Norwich, United Kingdom; Halle, Germany; and Oulu, Finland. Genotypes originating from geographic regions near the planting site had high relative fitness in each site, direct evidence for broad-scale geographic adaptation in this model species. However, genotypes originating in sites historically warmer than the planting site had higher average relative fitness than local genotypes in every site, especially at the northern range limit in Finland. This result suggests that local adaptive optima have shifted rapidly with recent warming across the species’ native range. Climatic optima also differed among seasonal germination cohorts within the Norwich site, suggesting that populations occurring where summer germination is common may have greater evolutionary potential to persist under future warming. If adaptational lag has occurred over just a few decades in banked seeds of an annual species, it may be an important consideration for managing longer-lived species, as well as for attempts to conserve threatened populations through ex situ preservation. PMID:24843140

Wilczek, Amity M.; Cooper, Martha D.; Korves, Tonia M.; Schmitt, Johanna

2014-01-01

26

Lagging adaptation to warming climate in Arabidopsis thaliana.  

PubMed

If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer climates will outperform natives and may provide genetic potential for evolutionary rescue. We tested for lagging adaptation to warming climate using banked seeds of the annual weed Arabidopsis thaliana in common garden experiments in four sites across the species' native European range: Valencia, Spain; Norwich, United Kingdom; Halle, Germany; and Oulu, Finland. Genotypes originating from geographic regions near the planting site had high relative fitness in each site, direct evidence for broad-scale geographic adaptation in this model species. However, genotypes originating in sites historically warmer than the planting site had higher average relative fitness than local genotypes in every site, especially at the northern range limit in Finland. This result suggests that local adaptive optima have shifted rapidly with recent warming across the species' native range. Climatic optima also differed among seasonal germination cohorts within the Norwich site, suggesting that populations occurring where summer germination is common may have greater evolutionary potential to persist under future warming. If adaptational lag has occurred over just a few decades in banked seeds of an annual species, it may be an important consideration for managing longer-lived species, as well as for attempts to conserve threatened populations through ex situ preservation. PMID:24843140

Wilczek, Amity M; Cooper, Martha D; Korves, Tonia M; Schmitt, Johanna

2014-06-01

27

Climatic warming disrupts recurrent Alpine insect outbreaks  

PubMed Central

Climate change has been identified as a causal factor for diverse ecological changes worldwide. Warming trends over the last couple of decades have coincided with the collapse of long-term population cycles in a broad range of taxa, although causal mechanisms are not well-understood. Larch budmoth (LBM) population dynamics across the European Alps, a classic example of regular outbreaks, inexplicably changed sometime during the 1980s after 1,200 y of nearly uninterrupted periodic outbreak cycles. Herein, analysis of perhaps the most extensive spatiotemporal dataset of population dynamics and reconstructed Alpine-wide LBM defoliation records reveals elevational shifts in LBM outbreak epicenters that coincide with temperature fluctuations over two centuries. A population model supports the hypothesis that temperature-mediated shifting of the optimal elevation for LBM population growth is the mechanism for elevational epicenter changes. Increases in the optimal elevation for population growth over the warming period of the last century to near the distributional limit of host larch likely dampened population cycles, thereby causing the collapse of a millennium-long outbreak cycle. The threshold-like change in LBM outbreak pattern highlights how interacting species with differential response rates to climate change can result in dramatic ecological changes. PMID:21059922

Johnson, Derek M.; Büntgen, Ulf; Frank, David C.; Kausrud, Kyrre; Haynes, Kyle J.; Liebhold, Andrew M.; Esper, Jan; Stenseth, Nils Chr.

2010-01-01

28

Cold months in a warming climate  

NASA Astrophysics Data System (ADS)

The frequency of cold months in the 21st century is studied using the CMIP3 ensemble of climate model simulations, using month-, location- and model-specific threshold temperatures derived from the simulated 20th century climate. Unsurprisingly, cold months are projected to become less common, but not non-existent, under continued global warming. As a multi-model mean over the global land area excluding Antarctica and under the SRES A1B scenario, 14% of the months during the years 2011-2050 are simulated to be colder than the 20th century median for the same month, 1.3% colder than the 10th percentile, and 0.1% record cold. The geographic and seasonal variations in the frequency of cold months are strongly modulated by variations in the magnitude of interannual variability. Thus, for example, cold months are most infrequently simulated over the tropical oceans where the variability is smallest, not over the Arctic where the warming is largest.

Räisänen, Jouni; Ylhäisi, Jussi S.

2011-11-01

29

Early-Holocene Climate Change in Beringia: Mediation of Global-Warming Impacts by Regional-Scale Boundary-Condition Changes  

Microsoft Academic Search

The early Holocene transition from glacial to interglacial conditions that occurred ca. 13ka to 10ka in Beringia (eastern Siberia, Alaska, and northwestern Canada) was driven by the amplified seasonal cycle of northern hemisphere insolation and the accompanying changes in global ice volume, atmospheric composition, sea- surface temperature, and sea level. The climate of Beringia also was likely influenced by changes

M. E. Edwards; P. J. Bartlein; S. W. Hostetler; S. L. Shafer; P. M. Anderson; L. B. Brubaker

2006-01-01

30

The Medieval Warm Period, the Little Ice Age and simulated climatic variability  

Microsoft Academic Search

The CSIRO Mark 2 coupled global climatic model has been used to generate a 10,000-year simulation for ‘present’ climatic conditions. The model output has been analysed to identify sustained climatic fluctuations, such as those attributed to the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Since no external forcing was permitted during the model run all such fluctuations

B. G. Hunt

2006-01-01

31

Shifting suitability for malaria vectors across Africa with warming climates  

PubMed Central

Background Climates are changing rapidly, producing warm climate conditions globally not previously observed in modern history. Malaria is of great concern as a cause of human mortality and morbidity, particularly across Africa, thanks in large part to the presence there of a particularly competent suite of mosquito vector species. Methods I derive spatially explicit estimates of human populations living in regions newly suitable climatically for populations of two key Anopheles gambiae vector complex species in Africa over the coming 50 years, based on ecological niche model projections over two global climate models, two scenarios of climate change, and detailed spatial summaries of human population distributions. Results For both species, under all scenarios, given the changing spatial distribution of appropriate conditions and the current population distribution, the models predict a reduction of 11.3–30.2% in the percentage of the overall population living in areas climatically suitable for these vector species in coming decades, but reductions and increases are focused in different regions: malaria vector suitability is likely to decrease in West Africa, but increase in eastern and southern Africa. Conclusion Climate change effects on African malaria vectors shift their distributional potential from west to east and south, which has implications for overall numbers of people exposed to these vector species. Although the total is reduced, malaria is likely to pose novel public health problems in areas where it has not previously been common. PMID:19426558

2009-01-01

32

Warm rain and climate: VOCALS, CloudSat, Models  

E-print Network

Warm rain and climate: VOCALS, CloudSat, Models Robert Wood University of Washington #12;Warm. (2008) Warm rain rate and its sensitivity to aerosols/microphysics is important and unknown #12;Cloud GHz)Rain rate to reflectivity (94 GHz) · Several steps need to be taken to compareSeveral steps need

Wood, Robert

33

Global warming and Arctic climate. Raymond S. Bradley  

E-print Network

Global warming and Arctic climate. Raymond S. Bradley Climate System Research Center University around the world; express all as anomalies from 1961-90 average #12;#12;Overall trend is upward ("global warming") 9 of the 10 warmest years have occurred since 1990 Greenhouse gas "forcing" became increasingly

Mountziaris, T. J.

34

Regional news portrayals of global warming and climate change  

Microsoft Academic Search

In this study we utilize content analysis techniques to examine how the issue of global warming and climate change has been characterized during the period of 1992 through 2005 by the Houston Chronicle—the largest regional newspaper in the Texas coastal region. A total of 795 global warming and climate change news articles from the Houston Chronicle are collected, coded and

Xinsheng Liu; Arnold Vedlitz; Letitia Alston

2008-01-01

35

How to preserve the tundra in a warming climate?  

NASA Astrophysics Data System (ADS)

The warming climate of the polar regions may change much of the current arctic-alpine tundra to forest or dense scrubland. This modification requires adaptation by traditional livelihoods such as reindeer herding, which relies on diverse, seasonal pasturelands. Vegetation change may also trigger positive warming feedbacks, where more abundant forest-scrub vegetation will decrease the global albedo. NCoE Tundra team investigates the complex climate-animal-plant interaction of the tundra ecosystem and aim to unravel the capability of herbivorous mammals to control the expansion of woody vegetation. Our interdisciplinary approach involves several work packages, whose results will be summarised in the presentation. In the ecological WPs, we study the dynamics of the natural food chains involving small herbivorous and the impacts of reindeer on the vegetation and the population dynamics of those arctic-alpine plants, which are most likely to become threatened in a warmer climate. Our study demonstrates the potential of a relatively sparse reindeer stocks (2-5 heads per km2) together with natural populations of arvicoline rodents to prevent the expansion of erect woody plants at the arctic-alpine timberline. In the climatic WPs we study the impact of grazing-dependent vegetation differences on the fraction of solar energy converted to heat. In the socio-economic WPs, we study the conditions for maintaining the economic and cultural viability of reindeer herding while managing the land use so that the arctic-alpine biota would be preserved.

Käyhkö, Jukka

2014-05-01

36

Experimental evaluation of reproductive response to climate warming in an oviparous skink.  

PubMed

The impact of climate warming on organisms is increasingly being recognized. The experimental evaluation of phenotypically plastic responses to warming is a critical step in understanding the biological effects and adaptive capacity of organisms to future climate warming. Oviparous Scincella modesta live in deeply-shaded habitats and they require low optimal temperatures during embryonic development, which makes them suitable subjects for testing the effects of warming on reproduction. We raised adult females and incubated their eggs under different thermal conditions that mimicked potential climate warming. Female reproduction, embryonic development and hatchling traits were monitored to evaluate the reproductive response to warming. Experimental warming induced females to lay eggs earlier, but it did not affect the developmental stage of embryos at oviposition or the reproductive output. The high temperatures experienced by gravid females during warming treatments reduced the incubation period and increased embryonic mortality. The locomotor performance of hatchlings was not affected by the maternal thermal environment, but it was affected by the warming treatment during embryonic development. Our results suggest that climate warming might have a profound effect on fitness-relevant traits both at embryonic and post-embryonic stages in oviparous lizards. PMID:23731813

Lu, Hongliang; Wang, Yong; Tang, Wenqi; DU, Weiguo

2013-06-01

37

Modelling middle pliocene warm climates of the USA  

USGS Publications Warehouse

The middle Pliocene warm period represents a unique time slice in which to model and understand climatic processes operating under a warm climatic regime. Palaeoclimatic model simulations, focussed on the United States of America (USA), for the middle Pliocene (ca 3 Ma) were generated using the USGS PRISM2 2?? ?? 2?? data set of boundary conditions and the UK Meteorological Office's HadAMS General Circulation Model (GCM). Model results suggest that conditions in the USA during the middle Pliocene can be characterised as annually warmer (by 2?? to 4??C), less seasonal, wetter (by a maximum of 4 to 8 mm/day) and with an absence of freezing winters over the central and southern Great Plains. A sensitivity experiment suggests that the main forcing mechanisms for surface temperature changes in near coastal areas are the imposed Pliocene sea surface temperatures (SST's). In interior regions, reduced Northern Hemisphere terrestrial ice, combined with less snow cover and a reduction in the elevation of the western cordillera of North America, generate atmospheric circulation changes and positive albedo feedbacks that raise surface temperatures. A complex set of climatic feedback mechanisms cause an enhancement of the hydrological cycle magnifying the moisture bearing westerly wind belt during the winter season (Dec., Jan., Feb.). Predictions produced by the model are in broad agreement with available geological evidence. However, the GCM appears to underestimate precipitation levels in the interior and central regions of the southern USA. Copyright: Palaeontological Association, 22 June 2001.

Haywood, A.M.; Valdes, P.J.; Sellwood, B.W.; Kaplan, J.O.; Dowsett, H.J.

2001-01-01

38

Ocean biogeochemistry in the warm climate of the late Paleocene  

NASA Astrophysics Data System (ADS)

The late Paleocene is characterized by warm and stable climatic conditions that served as the background climate for the Paleocene-Eocene Thermal Maximum (PETM, ~55 million years ago). With respect to feedback processes in the carbon cycle, the ocean biogeochemical background state is of major importance for projecting the climatic response to a carbon perturbation related to the PETM. Therefore, we use the Hamburg Ocean Carbon Cycle model (HAMOCC), embedded in the ocean general circulation model of the Max Planck Institute for Meteorology, MPIOM, to constrain the ocean biogeochemistry of the late Paleocene. We focus on the evaluation of modeled spatial and vertical distributions of the ocean carbon cycle parameters in a long-term warm steady-state ocean, based on a 560 ppm CO2 atmosphere. Model results are discussed in the context of available proxy data and simulations of pre-industrial conditions. Our results illustrate that ocean biogeochemistry is shaped by the warm and sluggish ocean state of the late Paleocene. Primary production is slightly reduced in comparison to the present day; it is intensified along the Equator, especially in the Atlantic. This enhances remineralization of organic matter, resulting in strong oxygen minimum zones and CaCO3 dissolution in intermediate waters. We show that an equilibrium CO2 exchange without increasing total alkalinity concentrations above today's values is achieved. However, consistent with the higher atmospheric CO2, the surface ocean pH and the saturation state with respect to CaCO3 are lower than today. Our results indicate that, under such conditions, the surface ocean carbonate chemistry is expected to be more sensitive to a carbon perturbation (i.e., the PETM) due to lower CO32- concentration, whereas the deep ocean calcite sediments would be less vulnerable to dissolution due to the vertically stratified ocean.

Heinze, M.; Ilyina, T.

2015-01-01

39

Linking climate change and biological invasions: Ocean warming facilitates nonindigenous  

E-print Network

Linking climate change and biological invasions: Ocean warming facilitates nonindigenous species October 2, 2002 (received for review July 23, 2002) The spread of exotic species and climate change suggest that the greatest effects of climate change on biotic communities may be due to changing maximum

Stachowicz, Jay

40

Soil respiration under climate warming: differential response of heterotrophic and autotrophic respiration.  

PubMed

Despite decades of research, how climate warming alters the global flux of soil respiration is still poorly characterized. Here, we use meta-analysis to synthesize 202 soil respiration datasets from 50 ecosystem warming experiments across multiple terrestrial ecosystems. We found that, on average, warming by 2 °C increased soil respiration by 12% during the early warming years, but warming-induced drought partially offset this effect. More significantly, the two components of soil respiration, heterotrophic respiration and autotrophic respiration showed distinct responses. The warming effect on autotrophic respiration was not statistically detectable during the early warming years, but nonetheless decreased with treatment duration. In contrast, warming by 2 °C increased heterotrophic respiration by an average of 21%, and this stimulation remained stable over the warming duration. This result challenged the assumption that microbial activity would acclimate to the rising temperature. Together, our findings demonstrate that distinguishing heterotrophic respiration and autotrophic respiration would allow us better understand and predict the long-term response of soil respiration to warming. The dependence of soil respiration on soil moisture condition also underscores the importance of incorporating warming-induced soil hydrological changes when modeling soil respiration under climate change. PMID:24771521

Wang, Xin; Liu, Lingli; Piao, Shilong; Janssens, Ivan A; Tang, Jianwu; Liu, Weixing; Chi, Yonggang; Wang, Jing; Xu, Shan

2014-10-01

41

Why tropical forest lizards are vulnerable to climate warming  

PubMed Central

Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards are useful for evaluating risks of warming because their thermal biology is well studied. We conducted macrophysiological analyses of diurnal lizards from diverse latitudes plus focal species analyses of Puerto Rican Anolis and Sphaerodactyus. Although tropical lowland lizards live in environments that are warm all year, macrophysiological analyses indicate that some tropical lineages (thermoconformers that live in forests) are active at low body temperature and are intolerant of warm temperatures. Focal species analyses show that some tropical forest lizards were already experiencing stressful body temperatures in summer when studied several decades ago. Simulations suggest that warming will not only further depress their physiological performance in summer, but will also enable warm-adapted, open-habitat competitors and predators to invade forests. Forest lizards are key components of tropical ecosystems, but appear vulnerable to the cascading physiological and ecological effects of climate warming, even though rates of tropical warming may be relatively low. PMID:19324762

Huey, Raymond B.; Deutsch, Curtis A.; Tewksbury, Joshua J.; Vitt, Laurie J.; Hertz, Paul E.; Álvarez Pérez, Héctor J.; Garland, Theodore

2009-01-01

42

The European climate under a 2?°C global warming  

NASA Astrophysics Data System (ADS)

A global warming of 2?°C relative to pre-industrial climate has been considered as a threshold which society should endeavor to remain below, in order to limit the dangerous effects of anthropogenic climate change. The possible changes in regional climate under this target level of global warming have so far not been investigated in detail. Using an ensemble of 15 regional climate simulations downscaling six transient global climate simulations, we identify the respective time periods corresponding to 2?°C global warming, describe the range of projected changes for the European climate for this level of global warming, and investigate the uncertainty across the multi-model ensemble. Robust changes in mean and extreme temperature, precipitation, winds and surface energy budgets are found based on the ensemble of simulations. The results indicate that most of Europe will experience higher warming than the global average. They also reveal strong distributional patterns across Europe, which will be important in subsequent impact assessments and adaptation responses in different countries and regions. For instance, a North-South (West-East) warming gradient is found for summer (winter) along with a general increase in heavy precipitation and summer extreme temperatures. Tying the ensemble analysis to time periods with a prescribed global temperature change rather than fixed time periods allows for the identification of more robust regional patterns of temperature changes due to removal of some of the uncertainty related to the global models’ climate sensitivity.

Vautard, Robert; Gobiet, Andreas; Sobolowski, Stefan; Kjellström, Erik; Stegehuis, Annemiek; Watkiss, Paul; Mendlik, Thomas; Landgren, Oskar; Nikulin, Grigory; Teichmann, Claas; Jacob, Daniela

2014-03-01

43

Global Climate Change: The Effects of Global Warming  

NSDL National Science Digital Library

In this lesson, students conduct an experiment to learn about CO2 levels found in four different gases. Through this experiment and a set of multimedia resources, they will learn how atmospheric levels of CO2 relate to climate change and global warming, explore the effects of global warming on the environment (as indicated by the changes in Earth's glacial ice), and consider human contributions to global warming, particularly from the use of automobiles.

2005-01-01

44

The Impact of Boreal Forest Fire on Climate Warming  

E-print Network

fire, integrating the effects of greenhouse gases, aerosols,and the effects from the remaining greenhouse gases in thegreenhouse gases emitted by fire contribute to climate warming, understanding the net effect

2006-01-01

45

Modeling the Impact of Warming in Climate Change Economics  

E-print Network

Any economic analysis of climate change policy requires some model that describes the impact of warming on future GDP and consumption. Most integrated assessment models (IAMs) relate temperature to the level of real GDP ...

Pindyck, Robert S.

46

The Climate Policy Narrative for a Dangerously Warming World  

SciTech Connect

It is time to acknowledge that global average temperatures will likely rise above the 2 C policy target and consider how that deeply troubling prospect should affect priorities for communicating and managing the risks of a dangerously warming climate.

Sanford, Todd [Union of Concerned Scientists] [Union of Concerned Scientists; Frumhoff, Peter [Union of Concerned Scientists] [Union of Concerned Scientists; Luers, Amy [Skoll Global Threats Fund] [Skoll Global Threats Fund; Gulledge, Jay [ORNL] [ORNL

2014-01-01

47

Estimating the Potential for Adaptation of Corals to Climate Warming  

Microsoft Academic Search

The persistence of tropical coral reefs is threatened by rapidly increasing climate warming, causing a functional breakdown of the obligate symbiosis between corals and their algal photosymbionts (Symbiodinium) through a process known as coral bleaching. Yet the potential of the coral-algal symbiosis to genetically adapt in an evolutionary sense to warming oceans is unknown. Using a quantitative genetics approach, we

Nikolaus B. M. Császár; Peter J. Ralph; Richard Frankham; Ray Berkelmans; Madeleine J. H. van Oppen; Robert Desalle

2010-01-01

48

Above-and belowground linkages in Sphagnum-peatland: climate warming affects plant-microbial interactions  

E-print Network

global warming is causing ecological communities to rapidly change, resulting in modifications1 Above- and belowground linkages in Sphagnum-peatland: climate warming affects plant) Running title: Warming affects plant-microbial interactions Keywords: aboveground, belowground, climate

Paris-Sud XI, Université de

49

Patterns of decadal-scale Arctic warming events in simulated climate  

NASA Astrophysics Data System (ADS)

Pronounced positive decadal-scale temperature anomalies occurred in the Arctic region in the first half of the twentieth century, an episode known as the early twentieth century warming (ETCW). Analyzing a 3,000-year unperturbed climate simulation performed with the Max Planck Institute Earth System Model, we demonstrate that internal variability of the Northern Hemisphere climate system is sufficient to reproduce warm events matching the observed ETCW. We perform a superposed epoch analysis on simulated data and identify 26 Arctic warming episodes compatible with the ETCW. The simulated events reproduce, in their ensemble average, magnitude as well as spatial and temporal extent of the observed ETCW. In individual realizations, the ETCW-like events indicate that different patterns of internally generated decadal Arctic warming are possible, including pan-Arctic warming events. We investigate the dynamics that typically lead to the simulated warming events: positive oceanic heat transport anomalies that form in the North Atlantic initialize the warming events and trigger an ocean-ice-albedo feedback in the Barents Sea region. The consequent reduction in sea-ice extent leads to enhanced multi-year surface warming through strengthened ocean heat release to the atmosphere. The oceanic heat transport anomalies reduce to pre-event levels around the year of the maximum warming. However, the warming events typically lasts for another 5-7 years until the sea-ice extent recovers to pre-event conditions.

Beitsch, Alexander; Jungclaus, Johann H.; Zanchettin, Davide

2014-10-01

50

Terrestrial Carbon Cycle Feedback to Climate Warming: Experimental Evidence  

NASA Astrophysics Data System (ADS)

Global climate modeling has demonstrated that climate warming would stimulate respiratory CO2 release from the terrestrial ecosystems to the atmosphere, which in turn leads to more warming in the climate system. This positive feedback between the climate change and the terrestrial carbon cycle can form a vicious cycle that potentially leads to a dangerous threat to ecosystem functioning and service. Some of the key processes underlying this feedback loop, however, have not been carefully examined by experimental studies. Those key processes include temperature sensitivity of ecosystem carbon influx; regulation of carbon processes by warming-induced changes in species composition, and nutrient and water availability; and phenology and timing of ecosystem processes under warming. We have conducted two warming experiments in a Southern Great Plains prairie to examine ecosystem responses to climate warming. We used infrared heaters to elevate soil temperature by approximately 2.0 and 4.0 oC, respectively, during the experimental period. Our results indicate that plant biomass growth increased by approximately 20% in the warmed plots in comparison to that in the control plots. The increased plant productivity likely resulted from extended length of growing seasons since warming advanced phenology of early-flowering species and delayed phenology of late-flowering species, leading to an extension of the growing season. Leaf photosynthesis, however, was not strongly affected by warming. Warming also considerably increased C4 plant biomass and caused slight decreases in growth of C3 plants. Increased C4 biomass and litter production resulted in decreases in quality and decomposition of bulk litter at the ecosystem scale, leading to an increase in litter mass at the soil surface. Soil respiration did not significantly increase in the first two years but increased by 8-10% in the last several years, largely due to increased root respiration and litter pool sizes. We did not observe much change in soil C content under warming, indicating that increased plant biomass counterbalanced the increased carbon loss via respiration. The increased biomass production was accompanied by increases in plant nitrogen uptake and use efficiency. Decreased litter quality and increased litter pools may trigger a negative nitrogen feedback to decrease nitrogen releases from litter and availability for plants over time. Overall, our data from the Great Plains prairie do not support the notion that warming stimulation of soil respiration is the major feedback process to climate change. A realistic prediction of the future carbon cycle and climate change may require more ecosystem processes other than the respiration to be incorporated into climate models.

Luo, Y.; Zhou, X.; Sherry, R.

2006-12-01

51

The capacity to cope with climate warming declines from temperate to tropical latitudes in two widely distributed Eucalyptus species.  

PubMed

As rapid climate warming creates a mismatch between forest trees and their home environment, the ability of trees to cope with warming depends on their capacity to physiologically adjust to higher temperatures. In widespread species, individual trees in cooler home climates are hypothesized to more successfully acclimate to warming than their counterparts in warmer climates that may approach thermal limits. We tested this prediction with a climate-shift experiment in widely distributed Eucalyptus tereticornis and E. grandis using provenances originating along a ~2500 km latitudinal transect (15.5-38.0°S) in eastern Australia. We grew 21 provenances in conditions approximating summer temperatures at seed origin and warmed temperatures (+3.5 °C) using a series of climate-controlled glasshouse bays. The effects of +3.5 °C warming strongly depended on home climate. Cool-origin provenances responded to warming through an increase in photosynthetic capacity and total leaf area, leading to enhanced growth of 20-60%. Warm-origin provenances, however, responded to warming through a reduction in photosynthetic capacity and total leaf area, leading to reduced growth of approximately 10%. These results suggest that there is predictable intraspecific variation in the capacity of trees to respond to warming; cool-origin taxa are likely to benefit from warming, while warm-origin taxa may be negatively affected. PMID:25378195

Drake, John E; Aspinwall, Michael J; Pfautsch, Sebastian; Rymer, Paul D; Reich, Peter B; Smith, Renee A; Crous, Kristine Y; Tissue, David T; Ghannoum, Oula; Tjoelker, Mark G

2015-01-01

52

Implication of climate warming for agricultural production in eastern China  

Microsoft Academic Search

According to the regional climate change scenarios for China estimated by the composite GCM, the potential impacts of climate warming on rice, winter wheat and corn production in eastern agricultural areas and cropping systems in China in future are simulated in this paper, using the weather-yield model and cropping system model. As a result, it is shown that under the

Wang Futang

1996-01-01

53

Climatic unpredictability and parasitism of caterpillars: Implications of global warming  

E-print Network

interactions and potential changes in ecosystem function that are associated with climate change (3, 4Climatic unpredictability and parasitism of caterpillars: Implications of global warming J. O 63121; Department of Biology, University of Utah, Salt Lake City, UT 84112; Yanayacu Biological Station

Coley, Phyllis

54

Impact of global warming and climate change on social development  

Microsoft Academic Search

In recent years there has been a lot of discussion on global warming and climate change and its implications for social development – an area that Mohan has devoted his life to. It is now accepted that climate change is real and its impacts will be felt across different sectors ranging from water resources to industries to social arenas. In

Ashok K. Mishra; Vijay P. Singh; Sharad K. Jain

2010-01-01

55

Simulated increase of hurricane intensities in a CO{sub 2}-warmed climate  

SciTech Connect

Hurricanes can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of these powerful storms could change in response to greenhouse gas-induced global warming. The impact of climate warming on hurricane intensities was investigated with a regional, high-resolution, hurricane prediction model. In a case study, 51 western Pacific storm cases under present-day climate conditions were compared with 51 storm cases under high-CO{sub 2} conditions. More idealized experiments were also performed. The large-scale initial conditions were derived from a global climate model. For a sea surface temperature warming of about 2.2{degree}C, the simulations yielded hurricanes that were more intense by 3 to 7 meters per second (5 to 12 percent) for wind speed and 7 to 20 millibars for central surface pressure. 26 refs., 4 figs.

Knutson, T.R.; Tuleya, R.E.; Kurihara, Y. [National Oceanic and Atmospheric Administration, Princeton, NJ (United States)] [National Oceanic and Atmospheric Administration, Princeton, NJ (United States)

1998-02-13

56

Peatland Carbon Dynamics in Alaska During Past Warm Climates  

NASA Astrophysics Data System (ADS)

Peatlands represent a large belowground carbon (C) pool in the biosphere. However, how peatland C sequestration capacity varies with changes in climate and climate-induced disturbance is still poorly understood and debated. Here we summarize results from Alaskan peatlands to document how peat C accumulation has responded to past warm climate intervals. We find that the greatest C accumulation rates at sites from the Kenai Peninsula to the North Slope occurred during the Holocene thermal maximum (HTM) in the early Holocene. This time period also corresponds with explosive formation and expansion of new peatlands on the landscape across Alaska. In addition, we note that many peatlands that existed during the earlier Holocene on the North Slope have disappeared and are presently covered by mineral soils under tundra or sandy deposits. During the Medieval Climate Anomaly (MCA) around 1000-500 years ago, several peatlands in Alaska show high rates of C accumulation when compared to the period before the MCA during the Neoglacial or the following Little Ice Age period. Altogether, our results indicate that the Alaskan landscape was very different during the last 10,000 years and that peatlands can rapidly accumulate C under warm climatic conditions. We speculate that warmth-stimulated increase in plant production surpasses increase in peat decomposition during the early Holocene, and potentially also during the MCA. Other factors that might have contributed to rapid peat accumulation during the early Holocene include increased summer sunlight, lowered sea levels, and decreased sea-ice cover/duration. Summer insolation was ca. 8% higher than today during the early Holocene due to orbital variations, which likely promoted plant productivity by increasing growing seasons sunlight. Furthermore, lower sea levels and exposed shallow continental shelves in the Beaufort Sea (Arctic Ocean) would have made the present-day Arctic Coastal Plain more continental, with warmer summers and colder winters, also reducing non-growing season decomposition. Reduced summer sea ice cover would also mediate and increase summer temperatures on the North Slope. Overall, our results show that, contrary to conventional wisdom, cool and wet climates such as those that characterized the Neoglacial period may result in peatland flooding (too much water), thereby limiting peat accumulation in these wet and cold regions. If the observations from northern Alaska are also applicable to other high-latitude regions with possible 'disappeared peatlands', our findings have important implications for understanding the role of peatlands in the global C cycle in the past and future.

Yu, Z.; Cleary, K.; Massa, C.; Hunt, S. J.; Klein, E. S.; Loisel, J.

2013-12-01

57

ENSO nonlinearity in a warming climate  

Microsoft Academic Search

The El Niño Southern Oscillation (ENSO) is known as the strongest natural inter-annual climate signal, having widespread consequences\\u000a on the global weather, climate, ecology and even on societies. Understanding ENSO variations in a changing climate is therefore\\u000a of primordial interest to both the climate community and policy makers. In this study, we focus on the change in ENSO nonlinearity\\u000a due

J. BoucharelB; B. Dewitte; Y. du Penhoat; B. Garel; S.-W. Yeh; J.-S. Kug

58

Terrestrial carbon cycle affected by non-uniform climate warming  

NASA Astrophysics Data System (ADS)

Feedbacks between the terrestrial carbon cycle and climate change could affect many ecosystem functions and services, such as food production, carbon sequestration and climate regulation. The rate of climate warming varies on diurnal and seasonal timescales. A synthesis of global air temperature data reveals a greater rate of warming in winter than in summer in northern mid and high latitudes, and the inverse pattern in some tropical regions. The data also reveal a decline in the diurnal temperature range over 51% of the global land area and an increase over only 13%, because night-time temperatures in most locations have risen faster than daytime temperatures. Analyses of satellite data, model simulations and in situ observations suggest that the impact of seasonal warming varies between regions. For example, spring warming has largely stimulated ecosystem productivity at latitudes between 30° and 90° N, but suppressed productivity in other regions. Contrasting impacts of day- and night-time warming on plant carbon gain and loss are apparent in many regions. We argue that ascertaining the effects of non-uniform climate warming on terrestrial ecosystems is a key challenge in carbon cycle research.

Xia, Jianyang; Chen, Jiquan; Piao, Shilong; Ciais, Philippe; Luo, Yiqi; Wan, Shiqiang

2014-03-01

59

Global Warming What is Climate? Ocean's Role in Climate Change Uncertainty Quantification, the Next Frontier The Role Played by Oceans in Climate  

E-print Network

Global Warming What is Climate? Ocean's Role in Climate Change Uncertainty Quantification, the Next Department University of Arizona October 11, 2008 #12;Global Warming What is Climate? Ocean's Role in Climate, Undergraduate Students: 2. UQGQG #12;Global Warming What is Climate? Ocean's Role in Climate Change Uncertainty

Restrepo, Juan M.

60

Seasonal Climate Extremes : Mechanism, Predictability and Responses to Global Warming  

NASA Astrophysics Data System (ADS)

Climate extremes are rarely occurring natural phenomena in the climate system. They often pose one of the greatest environmental threats to human and natural systems. Statistical methods are commonly used to investigate characteristics of climate extremes. The fitted statistical properties are often interpolated or extrapolated to give an indication of the likelihood of a certain event within a given period or interval. Under changing climatic conditions, the statistical properties of climate extremes are also changing. It is an important scientific goal to predict how the properties of extreme events change. To achieve this goal, observational and model studies aimed at revealing important features are a necessary prerequisite. Notable progress has been made in understanding mechanisms that influence climate variability and extremes in many parts of the globe including Europe. However, some of the recently observed unprecedented extremes cannot be fully explained from the already identified forcing factors. A better understanding of why these extreme events occur and their sensitivity to certain reinforcing and/or competing factors is useful. Understanding their basic form as well as their temporal variability is also vital and can contribute to global scientific efforts directed at advancing climate prediction capabilities, particularly making skilful forecasts and realistic projections of extremes. In this thesis temperature and precipitation extremes in Europe and Africa, respectively, are investigated. Emphasis is placed on the mechanisms underlying the occurrence of the extremes, their predictability and their likely response to global warming. The focus is on some selected seasons when extremes typically occur. An atmospheric energy budget analysis for the record-breaking European Autumn 2006 event has been carried out with the goal to identify the sources of energy for the extreme event. Net radiational heating is compared to surface turbulent fluxes of energy and dynamic horizontal advection of heat. There is clear evidence that the central North Atlantic Ocean was the major source of energy for the Autumn 2006 extreme event. Within Europe, anomalously high atmospheric water-vapor loading played a significant role through its strong greenhouse effect which resulted in an increase of downwelling infrared flux to the surface. Potential influences and connections between boreal snow cover during the melt season (February--April) and near-surface temperature in the spring season are established. Large amounts of snow act as a precursor to cold spring seasons by altering the coupling between the land and the overlying air through a modification of the surface energy and hydrological processes. In operational numerical models, a snow signal is found to provide some seasonal forecast skill for cold spring seasons in Europe. Changes in the intensity of droughts and floods in Africa in response to global warming are investigated and compared with changes in mean precipitation simulated by an ensemble of climate models selected from the Intergovernmental Panel on Climate Change (IPCC) fourth assessment report (AR4) set. The model simulations are objectively combined using a Bayesian weighting procedure. In southern Africa south of about 15° S, the most robust climate-change signal is a shortening of the main rainfall season. This arises from a delayed onset of seasonal rainfall associated with a reduction in lower-tropospheric moisture advection from the southwestern Indian Ocean. The semi-arid areas closer to the Kalahari desert are projected to become drier, while the wet areas are projected to become wetter. East Africa is projected to get wet in the future climate, much wetter than other regions within the same latitudinal belt. The zonal asymmetry in tropical precipitation increase is associated with a shift towards positive Indian Ocean Zonal Mode (IOZM)-like events via an alteration in the structure of the Eastern Hemisphere Walker circulation.

Shongwe, M. E.

2010-01-01

61

Hydrologic Response and Watershed Sensitivity to Climate Warming in California's Sierra Nevada  

PubMed Central

This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air temperature uniformly by 2°, 4°, and 6°C, but leave other climatic variables unchanged from observed values. Results are analyzed for changes in mean annual flow, peak runoff timing, and duration of low flow conditions to highlight which watersheds are most resilient to climate warming within a region, and how individual watersheds may be affected by changes to runoff quantity and timing. Results are compared with current water resources development and ecosystem services in each watershed to gain insight into how regional climate warming may affect water supply, hydropower generation, and montane ecosystems. Overall, watersheds in the northern Sierra Nevada are most vulnerable to decreased mean annual flow, southern-central watersheds are most susceptible to runoff timing changes, and the central portion of the range is most affected by longer periods with low flow conditions. Modeling results suggest the American and Mokelumne Rivers are most vulnerable to all three metrics, and the Kern River is the most resilient, in part from the high elevations of the watershed. Our research seeks to bridge information gaps between climate change modeling and regional management planning, helping to incorporate climate change into the development of regional adaptation strategies for Sierra Nevada watersheds. PMID:20368984

Null, Sarah E.; Viers, Joshua H.; Mount, Jeffrey F.

2010-01-01

62

Global Warming - The Science of Climate Change  

Microsoft Academic Search

Extremely topical over recent years, global warming has been the subject of a huge and growing amount of literature. Current literature however tends to fall into two camps: that which is highly scientific in nature and inaccessible to the average student, and that which is directed to the \\

Frances Drake

2000-01-01

63

Geoengineering: Direct Mitigation of Climate Warming  

EPA Science Inventory

For Frank Princiotta?s book, Global Climate Change?The Technology Challenge With the concentrations of atmospheric greenhouse gases (GHGs) rising to levels unprecedented in the current glacial epoch, the earth?s climate system appears to be rapidly shifting into a warmer regime....

64

Northern Hemisphere ice-sheet responses to past climate warming  

NASA Astrophysics Data System (ADS)

During ice-age glacial maxima of the last ~2.6 million years, ice sheets covered large portions of the Northern Hemisphere. Records from the retreat of these ice sheets during deglaciations provide important insights into how ice sheets behave under a warming climate. During the last two deglaciations, the southernmost margins of land-based Northern Hemisphere ice sheets responded nearly instantaneously to warming caused by increased summertime solar energy reaching the Earth. Land-based ice sheets subsequently retreated at a rate commensurate with deglacial climate warming. By contrast, marine-based ice sheets experienced a delayed onset of retreat relative to warming from increased summertime solar energy, with retreat characterized by periods of rapid collapse. Both observations raise concern over the response of Earth's remaining ice sheets to carbon-dioxide-induced global warming. The almost immediate reaction of land-based ice margins to past small increases in summertime energy implies that the Greenland Ice Sheet could be poised to respond to continuing climate change. Furthermore, the prehistoric precedent of marine-based ice sheets undergoing abrupt collapses raises the potential for a less predictable response of the marine-based West Antarctic Ice Sheet to future climate change.

Carlson, Anders E.; Winsor, Kelsey

2012-09-01

65

Implication of climate warming for agricultural production in eastern areas of China  

SciTech Connect

Based on historical variation of temperature and precipitation, the potential effects of climate warming on rice, winter wheat and corn production in China are simulated in this paper, using the weather-yield model and cropping system model. As a result, it is shown that under the current planting systems and agrotechniques, the greenhouse climate warming effect upon the corn production is the most significant. Regionally, the meteorological conditions of agricultural production in the northern part of China will be more favorable than the south and the central part. And seasonally speaking, such impact in general will be apparent in Autumn.

Wang Futang

1996-12-31

66

Global Warming and Climate Change Science  

Microsoft Academic Search

Global climate change has emerged as a major scientific and political issue within a few short decades. Scientific evidence clearly indicates that this change is a result of a complex interplay between a number of human-related and natural earth systems. While the complexity of the earth-ocean-atmosphere system makes the understanding and prediction of global climate change very difficult, improved scientific

Atul Jain

2008-01-01

67

Projected changes of snow conditions and avalanche activity in a warming climate: a case study in the French Alps over the 2020-2050 and 2070-2100 periods  

NASA Astrophysics Data System (ADS)

Projecting changes in snow cover due to climate warming is important for many societal issues, including adaptation of avalanche risk mitigation strategies. Efficient modeling of future snow cover requires high resolution to properly resolve the topography. Here, we detail results obtained through statistical downscaling techniques allowing simulations of future snowpack conditions for the mid- and late 21st century in the French Alps under three climate change scenarios. Refined statistical descriptions of snowpack characteristics are provided with regards to a 1960-1990 reference period, including latitudinal, altitudinal and seasonal gradients. These results are then used to feed a statistical model of avalanche activity-snow conditions-meteorological conditions relationships, so as to produce the first prognoses at annual/seasonal time scales of future natural avalanche activity eventually based on past observations. The resulting statistical indicators are fundamental for the mountain economy in terms of changes anticipation. At all considered spatio-temporal scales, whereas precipitations are expected to remain quite stationary, temperature increase interacting with topography will control snow-related variables, for instance the rate of decrease of total and dry snow depths, and the successive increase/decrease of the wet snow pack. Overall, with regards to the reference period, changes are strong for the end of the 21st century, but already significant for the mid-century. Changes in winter are somewhat less important than in spring, but wet snow conditions will appear at high elevations earlier in the season. For a given altitude, the Southern French Alps will not be significantly more affected than the Northern French Alps, so that the snowpack characteristics will be preserved more lately in the southern massifs of higher mean altitude. Regarding avalanche activity, a general -20-30% decrease and interannual variability is forecasted, relatively strong compared to snow and meteorological parameters changes. This decrease is amplified in spring and at low altitude. In contrast, an increase of avalanche activity is expected in winter at high altitude because of earlier wet snow avalanches triggers, at least as long as a minimal snow cover will be present. Comparison with the outputs of the deterministic avalanche hazard model MEPRA shows generally consistent results but suggests that, even if the frequency of winters with high avalanche activity will clearly decrease, the decreasing trend may be less strong and smooth than suggested by the changes in snowpack characteristics. This important point for risk assessment pleads for further work focusing on shorter time scales. Finally, small differences between different climate change scenarios show the robustness of the predicted avalanche activity changes.

Castebrunet, H.; Eckert, N.; Giraud, G.; Durand, Y.; Morin, S.

2014-01-01

68

Hudson Bay Ringed Seal: Ecology in a Warming Climate  

Microsoft Academic Search

\\u000a Ringed seals (Phoca hispida) have evolved to exploit snow covered sea-ice platforms for reproduction and survival and may face critical challenges with\\u000a ongoing and predicted climate change. The Hudson Bay ecosystem is already showing signs of climate warming raising concerns\\u000a for the ecological, economical, and culturally-significant ringed seals of Hudson Bay. This chapter summarizes the current\\u000a knowledge on ringed seals

M. Chambellant

69

Climate and conflicts: the security risks of global warming  

Microsoft Academic Search

Since the publication of the fourth assessment report of the Intergovernmental Panel on Climate Change in 2007, the securitization\\u000a of global warming has reached a new level. Numerous public statements and a growing research literature have discussed the\\u000a potential security risks and conflicts associated with climate change. This article provides an overview of this debate and\\u000a introduces an assessment framework

Jürgen Scheffran; Antonella Battaglini

2011-01-01

70

Modelling the response of glaciers to climate warming  

Microsoft Academic Search

Dynamic ice-flow models for 12 glaciers and ice caps have been forced with various climate change scenarios. The volume of\\u000a this sample spans three orders of magnitude. Six climate scenarios were considered: from 1990 onwards linear warming rates\\u000a of 0.01, 0.02 and 0.04?K a-1, with and without concurrent changes in precipitation. The models, calibrated against the historic record of glacier

J. Oerlemans; B. Anderson; A. Hubbard; P. Huybrechts; T. Jóhannesson; W. H. Knap; M. J. Schmeits; A. P. Stroeven; J. Wallinga; Z. Zuo

1998-01-01

71

Global Warming, Climate Change and Glacier Retreat of Nepal Himalayas  

Microsoft Academic Search

Global average air temperature near the earth surface rose 0.74¡¾0.18¨¬C during the twentieth century. The Intergovernmental Panel on Climate Change (IPCC) concludes that observed increased globally averaged temperatures since mid-twentieth century is very likely due to the observed increment in anthropogenic greenhouse gas concentrations, which leads to warming of the surface and lower atmosphere by increasing the greenhouse effect. Climate

S. Shrestha; Y. Hisaki

2007-01-01

72

Climate Warming and Disease Risks for Terrestrial and Marine Biota  

NASA Astrophysics Data System (ADS)

Infectious diseases can cause rapid population declines or species extinctions. Many pathogens of terrestrial and marine taxa are sensitive to temperature, rainfall, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen development and survival rates, disease transmission, and host susceptibility. Although most host-parasite systems are predicted to experience more frequent or severe disease impacts with warming, a subset of pathogens might decline with warming, releasing hosts from disease. Recently, changes in El Niño-Southern Oscillation events have had a detectable influence on marine and terrestrial pathogens, including coral diseases, oyster pathogens, crop pathogens, Rift Valley fever, and human cholera. To improve our ability to predict epidemics in wild populations, it will be necessary to separate the independent and interactive effects of multiple climate drivers on disease impact.

Harvell, C. Drew; Mitchell, Charles E.; Ward, Jessica R.; Altizer, Sonia; Dobson, Andrew P.; Ostfeld, Richard S.; Samuel, Michael D.

2002-06-01

73

Direct impacts of recent climate warming on insect populations.  

PubMed

Effects of recent climate change have already been detected in many species, and, in particular, in insects. The present paper reviews the key impacts of global warming on insect development and dispersal. The effects of climate change appear to be much more complex than a simple linear response to an average increase in temperature. They can differ between seasons and bioclimatic regions. Earlier flight periods, enhanced winter survival and acceleration of development rates are the major insect responses. Differential response of insects and hosts to warming up might also lead to disruption of their phenological synchrony, but adaptive genetic processes are likely to quickly restore this synchrony. In a number of cases, warming results in removing or relocating the barriers that limit present species' ranges. It is also likely to facilitate the establishment and spread of invasive alien species. Finally, knowledge gaps are identified and future research interests are suggested. PMID:21392331

Robinet, Christelle; Roques, Alain

2010-06-01

74

Climate warming and disease risks for terrestrial and marine biota  

USGS Publications Warehouse

Infectious diseases can cause rapid population declines or species extinctions. Many pathogens of terrestrial and marine taxa are sensitive to temperature, rainfall, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen development and survival rates, disease transmission, and host susceptibility. Although most host-parasite systems are predicted to experience more frequent or severe disease impacts with warming, a subset of pathogens might decline with warming, releasing hosts from disease. Recently, changes in El Niño–Southern Oscillation events have had a detectable influence on marine and terrestrial pathogens, including coral diseases, oyster pathogens, crop pathogens, Rift Valley fever, and human cholera. To improve our ability to predict epidemics in wild populations, it will be necessary to separate the independent and interactive effects of multiple climate drivers on disease impact.

Harvell, C.D.; Mitchell, C.E.; Ward, J.R.; Altizer, S.; Dobson, A.P.; Ostfeld, R.S.; Samuel, M.D.

2002-01-01

75

Impacts of climate warming on terrestrial ectotherms across latitude  

E-print Network

Impacts of climate warming on terrestrial ectotherms across latitude Curtis A. Deutsch* , Joshua J for terrestrial ectotherms. Our analyses imply that, in the absence of ameliorating factors such as migration with the physiological sensitivity of organisms to that change (12). Ectotherms constitute the vast majority

Huey, Raymond B.

76

The Impact of Boreal Forest Fire on Climate Warming  

E-print Network

The Impact of Boreal Forest Fire on Climate Warming J. T. Randerson,1 * H. Liu,2 M. G. Flanner,1 S measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black of these processes (and their temporal and spatial scales) is important in managing northern forests to mitigate

Zender, Charles

77

Possible Impacts of Climatic Warming on Polar Bears  

Microsoft Academic Search

If climatic warming occurs, the first impacts on polar bears (Ursus maritirnus) will be felt at the southern limits of their distribution, such as in James and Hudson bays, where the whole population is already forced to fast for approximately four months when the sea ice melts during the summer. Prolonging the ice-free period will increase nutritional stress on this

ANDREW E. DEROCHER

1993-01-01

78

Climatic warming increases isoprene emission from a subarctic heath  

Microsoft Academic Search

Emissions of isoprene, a reactive hydrocarbon, from Subarctic vegetation are not well documented. However, the Arctic is likely to experience the most pronounced effects of climatic warming, which may increase temperature-dependent isoprene emission. Here, we assessed isoprene emission from a Subarctic heath subjected to a 3-4 degrees C increase in air temperature and mountain birch (Betula pubescens ssp. czerepanovii) litter

Päivi Tiiva; Patrick Faubert; Anders Michelsen; Toini Holopainen; Jarmo K. Holopainen; Riikka Rinnan

2008-01-01

79

Lightning Strikes Predicted to Increase as Climate Warms  

NASA Astrophysics Data System (ADS)

By the end of the 21st century, the frequency of lightning strikes in the United States may increase by 50% because of climate warming, up from an average 25 million lightning strikes per year, a paper published in the 13 November issue of Science reports.

Wendel, JoAnna

2014-11-01

80

CLIMATE WARMING AND WATER MANAGEMENT ADAPTATION FOR CALIFORNIA  

E-print Network

. LUND, RICHARD E. HOWITT, MARION W. JENKINS, MANUEL A. PULIDO, M´ELANIE TAUBER, RANDALL S. RITZEMACLIMATE WARMING AND WATER MANAGEMENT ADAPTATION FOR CALIFORNIA STACY K. TANAKA, TINGJU ZHU, JAY R-006-9079-5 c Springer 2006 #12;S. K. TANAKA ET AL. et al., 2002). The potential effects of climate change

Pasternack, Gregory B.

81

Seventh grade students' conceptions of global warming and climate change  

Microsoft Academic Search

The purpose of this study was to investigate seventh grade students' conceptions of global warming and climate change. The study was descriptive in nature and involved the collection of qualitative data from 91 seventh grade students from three different schools in the Midwest, USA. An open response and draw and explain assessment instrument was administered to students. These data were

Daniel P. Shepardson; Dev Niyogi; Soyoung Choi; Umarporn Charusombat

2009-01-01

82

Vertical gradient of climate change and climate tourism conditions in the Black Forest  

Microsoft Academic Search

Due to the public discussion about global and regional warming, the regional climate and the modified climate conditions are\\u000a analyzed exemplarily for three different regions in the southern Black Forest (southwest Germany). The driving question behind\\u000a the present study was how can tourism adapt to modified climate conditions and associated changes to the tourism potential\\u000a in low mountain ranges. The

Christina Endler; Karoline Oehler; Andreas Matzarakis

2010-01-01

83

Decision-making in Electricity Generation Based on Global Warming Potential and Life-cycle Assessment for Climate Change  

E-print Network

Global Warming Potential and Life-cycle Assessment for Climate Change"Global Warming Potential and Life-cycle Assessment for Climate Changeglobal warming potential (GWP) method. GWP is a method to compare the global climate change

Horvath, Arpad

2005-01-01

84

African agriculture especially vulnerable to warming climate  

NASA Astrophysics Data System (ADS)

Malnourishment across Africa could jump 40% by 2050 due to climate change, according to the Africa Agriculture Status Report 2014 (AASR), released on 2 September. With temperatures predicted to rise 1.5°C-2.5°C by midcentury, African smallholder farms, which are generally run by one family, are more vulnerable than ever, the report finds.

Wendel, JoAnna

2014-09-01

85

Polar Bears in a Warming Climate1  

Microsoft Academic Search

SYNOPSIS. Polar bears (Ursus maritimus) live throughout the ice-covered waters of the circumpolar Arctic, particularly in near shore annual ice over the continental shelf where biological productivity is highest. However, to a large degree under scenarios predicted by climate change models, these preferred sea ice habitats will be substantially altered. Spatial and temporal sea ice changes will lead to shifts

ANDREW E. DEROCHER; J. LUNN; IAN STIRLING

2004-01-01

86

Earth's Warming Climate: Are We Responsible?  

NSDL National Science Digital Library

This tutorial provides the evidence that the amount of CO² in the atmosphere has not been as high as it is currently for nearly half a million years and that this increase corresponds with data that human activity is responsible. Learners examine scientific data showing increases in both atmospheric becomes CO² and the Earth's average temperature and analyze changes in atmospheric concentration of CO² over time. They reflect on some of the barriers involved in teaching global climate change and how using data in the classroom may be used to overcome those barriers. Multimedia resources such as video clips, a data visualization exercise featuring digital resources on climate.nasa.gov, and an interview with NASA climate scientist, Dr. Gavin Schmidt, are included. This is the second of ten self-paced professional development modules providing opportunities for teachers to learn about climate change through first-hand data exploration. Lesson plans for middle and high school students, descriptions of data collection instruments, glossary links to vocabulary are included.

87

Climate warming and Great Lakes management  

SciTech Connect

A decision-analysis approach to determining the relevance of information on climate change for near-term Great Lakes management decisions is outlined. Simplified applications to decisions to preserve coastal wetlands and to regulate outflows from Lake Erie are presented as illustrations of the methodology.

Hobbs, B.F.; Chao, P.T.; Nayal, M.; Bogart, W.T. [Case Western Reserve Univ., Cleveland, OH (United States)

1994-12-31

88

Divergent tree growth response to recent climatic warming, Lake Clark National Park and Preserve, Alaska  

NASA Astrophysics Data System (ADS)

Many dendroclimatic studies have been conducted in Alaska to understand recent climate changes, identify past and current warming trends, and determine how climate change may influence ecosystems. Four new white spruce (Picea glauca [Moench] Voss) ring-width chronologies from four sites along a 30 kilometer north-south transect in the Lake Clark National Park and Preserve on the Alaskan Peninsula span a common interval from AD 1769 to 2003. Two sites show an internally consistent positive growth response to increasing April-July temperatures after 1950. The two other sites each contain two subpopulations showing varying growth responses. One subpopulation diverges from historical temperature data after 1950 and one shows increased growth consistent with warming or exceeds expected growth increases. The growth decline may be due to temperature-induced drought stress that acts on some trees. Unprecedented climatic changes are triggering diverse growth responses between and within study sites that may greatly complicate dendroclimatic reconstructions of past climate conditions.

Driscoll, William W.; Wiles, Gregory C.; D'Arrigo, Rosanne D.; Wilmking, Martin

2005-10-01

89

Climate warming and Bergmann's rule through time: is there any evidence?  

PubMed Central

Climate change is expected to induce many ecological and evolutionary changes. Among these is the hypothesis that climate warming will cause a reduction in body size. This hypothesis stems from Bergmann's rule, a trend whereby species exhibit a smaller body size in warmer climates, and larger body size under colder conditions in endotherms. The mechanisms behind this rule are still debated, and it is not clear whether Bergmann's rule can be extended to predict the effects of climate change through time. We reviewed the primary literature for evidence (i) of a decrease in body size in response to climate warming, (ii) that changing body size is an adaptive response and (iii) that these responses are evolutionary or plastic. We found weak evidence for changes in body size through time as predicted by Bergmann's rule. Only three studies investigated the adaptive nature of these size decreases. Of these, none reported evidence of selection for smaller size or of a genetic basis for the size change, suggesting that size decreases could be due to nonadaptive plasticity in response to changing environmental conditions. More studies are needed before firm conclusions can be drawn about the underlying causes of these changes in body size in response to a warming climate. PMID:24454554

Teplitsky, Celine; Millien, Virginie

2014-01-01

90

Climate warming will reduce growth and survival of Scots pine except in the far north  

E-print Network

range. Keywords Climate-change impacts, genetic variation, global warming, growth, intraspecific­597 I N T R O DU C T I O N Given that current climate projections are for warming by 1.4­5.8 °C globallyLETTER Climate warming will reduce growth and survival of Scots pine except in the far north P. B

Minnesota, University of

91

A brief history of climate the northern seas from the Last Glacial Maximum to global warming  

E-print Network

1 A brief history of climate ­ the northern seas from the Last Glacial Maximum to global warming maritime climate ­ from the Last Glacial Maximum through to the projected global warming of the 21st understanding of past, present, and projected future climate change in the northern seas region. Warm and cold

Drange, Helge

92

First tropical warm rain estimates could improve global climate models  

NSDL National Science Digital Library

This study breaks down the type of rainfall in the tropical zones. Microwave images and radar data from the Tropical Rainfall Measuring Mission were examined. It was found that approximately 72 percent of the total rain area and 31 percent of the total rain amount in the tropics comes from warm rain. The relationship between liquid water in a cloud and the rain rate was also measured. Results can be used in climate models to represent convection cycles and their role in global warming.

William Lau

93

The response of the tropical Indo-Pacific warm-pool to conditions of global warmth  

NASA Astrophysics Data System (ADS)

The Indo-Pacific warm pool (IPWP) plays an important role in both regional and global climate, but the response of this region to anthropogenic climate change is not well understood. Climate models are inconsistent in their predictions of sea surface temperature (SST) change in the region, with some models predicting warming in the IPWP due to greenhouse gas forcing and some indicating no change or a moderate cooling. While the early Pliocene warm period is not a perfect analogue for anthropogenic climate change, it is the most recent time in Earth history when global temperatures were warmer than they are today for a sustained period of time, and therefore arguable presents the best test-bed for looking at conditions of global warmth in the paleo record. We will present a Mg/Ca (G.sacculifer) sea surface temperature record from ODP site 758 in the eastern Indian Ocean and show that IPWP SST remained relatively stable through the last 5 Ma and was not warmer in the early Pliocene compared today. The stability of the IPWP through the last 5 Ma, even as SST in the EEP and coastal upwelling regions cooled significantly, presents a challenge to climate models to understand the mechanisms involved with a change from El Padre conditions to modern conditions so that we can more clearly predict future climate change.

Dekens, P. S.; Ravelo, A. C.

2008-12-01

94

Climate and tourism in the Black Forest during the warm season  

NASA Astrophysics Data System (ADS)

Climate, climate change and tourism all interact. Part of the public discussion about climate change focusses on the tourism sector, with direct and indirect impacts being of equally high relevance. Climate and tourism are closely linked. Thus, climate is a very decisive factor in choices both of destination and of type of journey (active holidays, wellness, and city tours) in the tourism sector. However, whether choices about destinations or types of trip will alter with climate change is difficult to predict. Future climates can be simulated and projected, and the tendencies of climate parameters can be estimated using global and regional climate models. In this paper, the focus is on climate change in the mountainous regions of southwest Germany - the Black Forest. The Black Forest is one of the low mountain ranges where both winter and summer tourism are vulnerable to climate change due to its southern location; the strongest climatic changes are expected in areas covering the south and southwest of Germany. Moreover, as the choice of destination is highly dependent on good weather, a climatic assessment for tourism is essential. Thus, the aim of this study was to estimate climatic changes in mountainous regions during summer, especially for tourism and recreation. The assessment method was based on human-biometeorology as well as tourism-climatologic approaches. Regional climate simulations based on the regional climate model REMO were used for tourism-related climatic analyses. Emission scenarios A1B and B1 were considered for the time period 2021 to 2050, compared to the 30-year base period of 1971-2000, particularly for the warm period of the year, defined here as the months of March-November. In this study, we quantified the frequency, but not the means, of climate parameters. The study results show that global and regional warming is reflected in an increase in annual mean air temperature, especially in autumn. Changes in the spring show a slight negative trend, which is in line with the trend of a decrease in physiologically equivalent temperature as well as in thermal comfort conditions. Due to the rising air temperature, heat stress as well as sultry conditions are projected to become more frequent, affecting human health and recreation, especially at lower lying altitudes. The tops of the mountains and higher elevated areas still have the advantage of offering comfortable climatic conditions.

Endler, Christina; Matzarakis, Andreas

2011-03-01

95

Warming Experiments Underpredict Plant Phenological Responses to Climate Change  

NASA Technical Reports Server (NTRS)

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.

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

96

Lungs in a warming world: climate change and respiratory health.  

PubMed

Climate change is a health threat no less consequential than cigarette smoking. Increased concentrations of greenhouse gases, and especially CO?, in the earth's atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, temperature variability, air pollution, forest fires, droughts, and floods, all of which put respiratory health at risk. These changes in climate and air quality substantially increase respiratory morbidity and mortality for patients with common chronic lung diseases such as asthma and COPD and other serious lung diseases. Physicians have a vital role in addressing climate change, just as they did with tobacco, by communicating how climate change is a serious, but remediable, hazard to their patients. PMID:23648909

Bernstein, Aaron S; Rice, Mary B

2013-05-01

97

Cold Climate, Warm Climates: How Can We Tell Past Temperatures?  

NSDL National Science Digital Library

This brief NASA article provides general information about paleoclimatology (the study of past climate). Focusing on ice core data and foraminifera (shelled marine microorganisms) in deep sea sediments, the article provides a summary of how paleoclimate can be inferred.

Gavin Schmidt

98

High Arctic wetting reduces permafrost carbon feedbacks to climate warming  

NASA Astrophysics Data System (ADS)

The carbon (C) balance of permafrost regions is predicted to be extremely sensitive to climatic changes. Major uncertainties exist in the rate of permafrost thaw and associated C emissions (33-508PgC or 0.04-1.69°C by 2100; refs , ) and plant C uptake. In the High Arctic, semi-deserts retain unique soil-plant-permafrost interactions and heterogeneous soil C pools (>12PgC ref. ). Owing to its coastal proximity, marked changes are expected for High Arctic tundra. With declining summer sea-ice cover, these systems are simultaneously exposed to rising temperatures, increases in precipitation and permafrost degradation. Here we show, using measurements of tundra-atmosphere C fluxes and soil C sources (14C) at a long-term climate change experiment in northwest Greenland, that warming decreased the summer CO2 sink strength of semi-deserts by up to 55%. In contrast, warming combined with wetting increased the CO2 sink strength by an order of magnitude. Further, wetting while relocating recently assimilated plant C into the deep soil decreased old C loss compared with the warming-only treatment. Consequently, the High Arctic has the potential to remain a strong C sink even as the rest of the permafrost region transitions to a net C source as a result of future global warming.

Lupascu, M.; Welker, J. M.; Seibt, U.; Maseyk, K.; Xu, X.; Czimczik, C. I.

2014-01-01

99

Greenhouse Effect/Climate Change/Global Warming  

NSDL National Science Digital Library

The terms greenhouse effect, climate change, and global warming are often used interchangeably, yet they really refer to three separate and distinct processes. This activity examines all three and assesses whether Earth's atmosphere is getting warmer. Students will read two articles from the journal of Science that discuss the findings of the Intergovernmental Panel on Climate Change (IPCC) and investigate the bias of both groups of authors. This activity requires the use of two articles from the July 20, 2001 issue of the journal Science.

Chris Fox

100

Microclimate impacts of passive warming methods in Antarctica: implications for climate change studies  

E-print Network

in descriptions of treatment effects. Keywords Antarctica Á Climate change Á Climate warming Á Extreme event ÁREVIEW Microclimate impacts of passive warming methods in Antarctica: implications for climate prediction of magnified (i.e. more rapid) climatic change in the polar regions, a prediction supported

Wall, Diana

101

The warming hole as an internal climate variability phenomenon  

NASA Astrophysics Data System (ADS)

A potentially outstanding manifestation of the effects of internal variability is the so-called warming hole that extends over the south-eastern United States. In this region no warming trend was detected during most of the 20th century and even a slight cooling was observed in the second half of the century. Although many mechanisms were proposed in the attempt to explain the presence of this peculiar feature (e.g. changes in land use and aerosol emissions), we demonstrate that the warming hole may have at least partly resulted from internal variability temporarily obscuring the warming signal in the region. The role of internal variability is tested using a 21-member ensemble generated by the fully coupled NCAR's Community Earth System Model (CESM) for the period 1950-2100 with slightly perturbed initial conditions. The possibility of simulating the warming hole in the reference period 1960-2004 is investigated by introducing a simple identification criterion based on near-surface temperature changes. Not unexpectedly, the warming hole does not appear in the simulated ensemble average temperature changes but is identified in 6 out of the 21 runs. In a perfect-model approach and assuming correct external forcing, this is suggestive of the fact that the warming hole may occur under particular circumstances due to internal variability. In a second step we explore what modes of variability account for the lack of warming in certain realisations of the model. To this end, a principal component analysis was performed on the set of the 21 simulated mean winter 500hPa geopotential height trend patterns over North America (10-90°N, 170°E-30°W) in the period 1960-2004. The first two EOFs collectively explain approximately 63% of the total variance and are recognised as representative of the time evolution of two different configurations of the Pacific/North American Pattern (PNA). Resorting to a regression method, the temperature trend contribution of this mode is then removed from individual runs, which results in the disappearance of the warming hole in filtered fields. Our experiment thus suggests that internal variability masking the warming signal may account for a large portion of the observed warming hole. In particular, the observed negative temperature trends in the south-eastern United States may have been produced by a long-term positive trend of the Pacific/North American Pattern, shifting towards a positive phase. Such a trend is indeed detectable in observations and is also evident in those model runs featuring a warming hole when looking at the time series of the principal component of the second EOF, associated with the warming hole structure.

Saffioti, Claudio; Fischer, Erich M.; Knutti, Reto

2014-05-01

102

Reductions in labour capacity from heat stress under climate warming  

NASA Astrophysics Data System (ADS)

A fundamental aspect of greenhouse-gas-induced warming is a global-scale increase in absolute humidity. Under continued warming, this response has been shown to pose increasingly severe limitations on human activity in tropical and mid-latitudes during peak months of heat stress. One heat-stress metric with broad occupational health applications is wet-bulb globe temperature. We combine wet-bulb globe temperatures from global climate historical reanalysis and Earth System Model (ESM2M) projections with industrial and military guidelines for an acclimated individual's occupational capacity to safely perform sustained labour under environmental heat stress (labour capacity)--here defined as a global population-weighted metric temporally fixed at the 2010 distribution. We estimate that environmental heat stress has reduced labour capacity to 90% in peak months over the past few decades. ESM2M projects labour capacity reduction to 80% in peak months by 2050. Under the highest scenario considered (Representative Concentration Pathway 8.5), ESM2M projects labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress. Uncertainties and caveats associated with these projections include climate sensitivity, climate warming patterns, CO2 emissions, future population distributions, and technological and societal change.

Dunne, John P.; Stouffer, Ronald J.; John, Jasmin G.

2013-06-01

103

Climatic Conditions in Classrooms.  

ERIC Educational Resources Information Center

Presents an overview of research on the ways in which classroom thermal environment, lighting conditions, ion state, and electromagnetic and air pollution affect learning and the performance of students and teachers. (SJL)

Kevan, Simon M.; Howes, John D.

1980-01-01

104

Heavy rainfall in future climate around the central Japan by pseudo global warming experiments  

NASA Astrophysics Data System (ADS)

The central part of Japan sometimes suffers from heavy rainfall derived by a typhoon. In 2000, a severe heavy rainfall attacked the central Japan. The maximum hourly precipitation in Aichi prefecture during this event was 114 mm, and daily precipitation 492 mm. On the other hand, it is reported that, in future climate, tropical cyclones (typhoons and hurricanes) will be stronger in IPCC AR4. In this study, variations in heavy rainfall around the central Japan are assessed by a pseudo global warming experiment using numerical weather prediction model. Based on the heavy rainfall event in 2000, pseudo global warming conditions are made from a reanalysis data and climate prediction in the 3rd phase of climate model intercomparison project (CMIP3), and simulations are made by the weather research forecasting model (WRF). The results of the control run of the heavy rainfall event in 2000 agree well with observed precipitation and same rainfall processes are found. In the pseudo global warming experiment using eight different CMIP3 output, five results show heavy rainfall around Aichi prefecture. Four results from the five heavy rainfalls show the larger maximum hourly precipitation, and the events continue longer than the control run. At the same time, using the same method, changes in precipitation characteristics around the central Japan are investigate for summer. The future climate conditions are obtained from dynamic downscaling by WRF using two pseudo global warming condition made with two CMIP3 projections (MPI ECHAM5 and CCCMA CGCM3.1 T47). The results show the opposite variation in future precipitation in the central Japan. In ECHAM5, summer precipitation increases in wide area, but the result with CCCMA shows decreasing precipitation especially in the Pacific side (see Figure). Such characteristics are found in the original CMIP3 output. Detail investigations of precipitation show that there are small variations in hourly precipitation in ECHAM5 and CCCMA. However, for three-hourly and six-hourly, ECHAM5 shows increasing precipitation in future but CCCMA decreasing. Those contradictions are thought to be caused by uncertainty of climate models used for making pseudo global warming conditions. Further study using many more CMIP3 model outputs is necessary for reliable assessment.; The difference in summer precipitation (June-August) between future and present climate around the central Japan. Left: result from pseudo global warming condition made with MPI ECHAM5. Right: result with CCCMA CGCM3.1 T47. The unit of color bar is mm.

Taniguchi, K.

2012-12-01

105

Permafrost carbon-climate feedbacks accelerate global warming.  

PubMed

Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. We have used a terrestrial ecosystem model that includes permafrost carbon dynamics, inhibition of respiration in frozen soil layers, vertical mixing of soil carbon from surface to permafrost layers, and CH(4) emissions from flooded areas, and which better matches new circumpolar inventories of soil carbon stocks, to explore the potential for carbon-climate feedbacks at high latitudes. Contrary to model results for the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), when permafrost processes are included, terrestrial ecosystems north of 60°N could shift from being a sink to a source of CO(2) by the end of the 21st century when forced by a Special Report on Emissions Scenarios (SRES) A2 climate change scenario. Between 1860 and 2100, the model response to combined CO(2) fertilization and climate change changes from a sink of 68 Pg to a 27 + -7 Pg sink to 4 + -18 Pg source, depending on the processes and parameter values used. The integrated change in carbon due to climate change shifts from near zero, which is within the range of previous model estimates, to a climate-induced loss of carbon by ecosystems in the range of 25 + -3 to 85 + -16 Pg C, depending on processes included in the model, with a best estimate of a 62 + -7 Pg C loss. Methane emissions from high-latitude regions are calculated to increase from 34 Tg CH(4)/y to 41-70 Tg CH(4)/y, with increases due to CO(2) fertilization, permafrost thaw, and warming-induced increased CH(4) flux densities partially offset by a reduction in wetland extent. PMID:21852573

Koven, Charles D; Ringeval, Bruno; Friedlingstein, Pierre; Ciais, Philippe; Cadule, Patricia; Khvorostyanov, Dmitry; Krinner, Gerhard; Tarnocai, Charles

2011-09-01

106

Permafrost carbon-climate feedbacks accelerate global warming  

PubMed Central

Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. We have used a terrestrial ecosystem model that includes permafrost carbon dynamics, inhibition of respiration in frozen soil layers, vertical mixing of soil carbon from surface to permafrost layers, and CH4 emissions from flooded areas, and which better matches new circumpolar inventories of soil carbon stocks, to explore the potential for carbon-climate feedbacks at high latitudes. Contrary to model results for the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), when permafrost processes are included, terrestrial ecosystems north of 60°N could shift from being a sink to a source of CO2 by the end of the 21st century when forced by a Special Report on Emissions Scenarios (SRES) A2 climate change scenario. Between 1860 and 2100, the model response to combined CO2 fertilization and climate change changes from a sink of 68 Pg to a 27 + -7 Pg sink to 4 + -18 Pg source, depending on the processes and parameter values used. The integrated change in carbon due to climate change shifts from near zero, which is within the range of previous model estimates, to a climate-induced loss of carbon by ecosystems in the range of 25 + -3 to 85 + -16 Pg C, depending on processes included in the model, with a best estimate of a 62 + -7 Pg C loss. Methane emissions from high-latitude regions are calculated to increase from 34 Tg CH4/y to 41–70 Tg CH4/y, with increases due to CO2 fertilization, permafrost thaw, and warming-induced increased CH4 flux densities partially offset by a reduction in wetland extent. PMID:21852573

Koven, Charles D.; Ringeval, Bruno; Friedlingstein, Pierre; Ciais, Philippe; Cadule, Patricia; Khvorostyanov, Dmitry; Krinner, Gerhard; Tarnocai, Charles

2011-01-01

107

Foraging by forest ants under experimental climatic warming: a test at two sites  

PubMed Central

Climatic warming is altering the behavior of individuals and the composition of communities. However, recent studies have shown that the impact of warming on ectotherms varies geographically: species at warmer sites where environmental temperatures are closer to their upper critical thermal limits are more likely to be negatively impacted by warming than are species inhabiting relatively cooler sites. We used a large-scale experimental temperature manipulation to warm intact forest ant assemblages in the field and examine the impacts of chronic warming on foraging at a southern (North Carolina) and northern (Massachusetts) site in eastern North America. We examined the influence of temperature on the abundance and recruitment of foragers as well as the number of different species observed foraging. Finally, we examined the relationship between the mean temperature at which a species was found foraging and the critical thermal maximum temperature of that species, relating functional traits to behavior. We found that forager abundance and richness were related to the experimental increase in temperature at the southern site, but not the northern site. Additionally, individual species responded differently to temperature: some species foraged more under warmer conditions, whereas others foraged less. Importantly, these species-specific responses were related to functional traits of species (at least at the Duke Forest site). Species with higher critical thermal maxima had greater forager densities at higher temperatures than did species with lower critical thermal maxima. Our results indicate that while climatic warming may alter patterns of foraging activity in predictable ways, these shifts vary among species and between sites. More southerly sites and species with lower critical thermal maxima are likely to be at greater risk to ongoing climatic warming. PMID:23531642

Stuble, Katharine L; Pelini, Shannon L; Diamond, Sarah E; Fowler, David A; Dunn, Robert R; Sanders, Nathan J

2013-01-01

108

Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history.  

PubMed

Rapid warming over the past 50?years on the Antarctic Peninsula is associated with the collapse of a number of ice shelves and accelerating glacier mass loss. In contrast, warming has been comparatively modest over West Antarctica and significant changes have not been observed over most of East Antarctica, suggesting that the ice-core palaeoclimate records available from these areas may not be representative of the climate history of the Antarctic Peninsula. Here we show that the Antarctic Peninsula experienced an early-Holocene warm period followed by stable temperatures, from about 9,200 to 2,500?years ago, that were similar to modern-day levels. Our temperature estimates are based on an ice-core record of deuterium variations from James Ross Island, off the northeastern tip of the Antarctic Peninsula. We find that the late-Holocene development of ice shelves near James Ross Island was coincident with pronounced cooling from 2,500 to 600?years ago. This cooling was part of a millennial-scale climate excursion with opposing anomalies on the eastern and western sides of the Antarctic Peninsula. Although warming of the northeastern Antarctic Peninsula began around 600 years ago, the high rate of warming over the past century is unusual (but not unprecedented) in the context of natural climate variability over the past two millennia. The connection shown here between past temperature and ice-shelf stability suggests that warming for several centuries rendered ice shelves on the northeastern Antarctic Peninsula vulnerable to collapse. Continued warming to temperatures that now exceed the stable conditions of most of the Holocene epoch is likely to cause ice-shelf instability to encroach farther southward along the Antarctic Peninsula. PMID:22914090

Mulvaney, Robert; Abram, Nerilie J; Hindmarsh, Richard C A; Arrowsmith, Carol; Fleet, Louise; Triest, Jack; Sime, Louise C; Alemany, Olivier; Foord, Susan

2012-09-01

109

Climate changes mirror global warming predictions BY THOMAS CROWLEY Guest columnist  

E-print Network

Climate changes mirror global warming predictions BY THOMAS CROWLEY Guest columnist The Herald" and must reflect, at least in part, the climate system response to the increase in global warming. What if we wanted to prevent global warming. This is just doomsday speaking of the same type that he

110

DO GLOBAL WARMING AND CLIMATE CHANGE REPRESENT A SERIOUS THREAT TO OUR WELFARE  

E-print Network

DO GLOBAL WARMING AND CLIMATE CHANGE REPRESENT A SERIOUS THREAT TO OUR WELFARE AND ENVIRONMENT? By Michael E. Mann I. Introduction The subjects of "global warming" and "climate change" have become parts of both the popular lexicon and the public discourse. Discussions of global warming often evoke passionate

111

Can ozone depletion and global warming interact to produce rapid climate change?  

E-print Network

Can ozone depletion and global warming interact to produce rapid climate change? Dennis L. Hartmann of Climate Change (IPCC) assess- ment of the status of global warming, which reported that winter stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible

Limpasuvan, Varavut

112

Geographic variation in vulnerability to climate warming in a tropical Caribbean lizard  

E-print Network

and physiological capacity would change assuming climate warming of 3 °C over the next century. 3. The mean TeGeographic variation in vulnerability to climate warming in a tropical Caribbean lizard Alex R-scale analyses have predicted global patterns of vulnerability to warming, with tropical species at higher risk

Leal, Manuel S.

113

Increased Climate Variability Is More Visible Than Global Warming: A General  

E-print Network

Increased Climate Variability Is More Visible Than Global Warming: A General System@utep.edu Abstract While global warming is a statistically confirmed long-term phenomenon, its most visible than the global warming itself. 1 Formulation of the Problem What is global warming. The term "global

Kreinovich, Vladik

114

Accelerated phenology of blacklegged ticks under climate warming.  

PubMed

The phenology of tick emergence has important implications for the transmission of tick-borne pathogens. A long lag between the emergence of tick nymphs in spring and larvae in summer should increase transmission of persistent pathogens by allowing infected nymphs to inoculate the population of naive hosts that can subsequently transmit the pathogen to larvae to complete the transmission cycle. In contrast, greater synchrony between nymphs and larvae should facilitate transmission of pathogens that do not produce long-lasting infections in hosts. Here, we use 19 years of data on blacklegged ticks attached to small-mammal hosts to quantify the relationship between climate warming and tick phenology. Warmer years through May and August were associated with a nearly three-week advance in the phenology of nymphal and larval ticks relative to colder years, with little evidence of increased synchrony. Warmer Octobers were associated with fewer larvae feeding concurrently with nymphs during the following spring. Projected warming by the 2050s is expected to advance the timing of average nymph and larva activity by 8-11 and 10-14 days, respectively. If these trends continue, climate warming should maintain or increase transmission of persistent pathogens, while it might inhibit pathogens that do not produce long-lasting infections. PMID:25688016

Levi, Taal; Keesing, Felicia; Oggenfuss, Kelly; Ostfeld, Richard S

2015-04-01

115

A field facility to simulate climate warming and increased nutrient supply in shallow aquatic ecosystems.  

PubMed

Global warming and excess nitrogen deposition can exert strong impacts on aquatic populations, communities, and ecosystems. However, experimental data to establish clear cause-and-effect relationships in naturally complex field conditions are scarce in aquatic environments. Here, we describe the design and performance of a unique outdoor enclosure facility used to simulate warming, increased nitrogen supply, and both factors combined in a littoral freshwater wetland dominated by common reed, Phragmites australis. The experimental system effectively simulated a 2.8 °C climate warming scenario over an extended period, capturing the natural temperature variations in the wetland at diel and seasonal scales with only small deviations. Excess nitrogen supply enhanced nitrate concentrations especially in winter when it was associated with increased concentration of ammonium and dissolved organic carbon. Nitrogen also reduced dissolved oxygen concentrations, particularly in the summer. Importantly, by stimulating biological activity, warming enhanced the nitrogen uptake capacity of the wetland during the winter, emphasizing the need for multifactorial global change experiments that examine both warming and nitrogen loading in concert. Establishing similar experiments across broad environmental gradients holds great potential to provide robust assessments of the impacts of climate change on shallow aquatic ecosystems. PMID:23836092

Hines, Jes; Hammrich, Arne; Steiner, Daniel; Gessner, Mark O

2013-12-01

116

The impact of global warming on the range distribution of different climatic groups of Aspidoscelis costata costata.  

PubMed

The ectothermic nature of reptiles makes them especially sensitive to global warming. Although climate change and its implications are a frequent topic of detailed studies, most of these studies are carried out without making a distinction between populations. Here we present the first study of an Aspidoscelis species that evaluates the effects of global warming on its distribution using ecological niche modeling. The aims of our study were (1) to understand whether predicted warmer climatic conditions affect the geographic potential distribution of different climatic groups of Aspidoscelis costata costata and (2) to identify potential altitudinal changes of these groups under global warming. We used the maximum entropy species distribution model (MaxEnt) to project the potential distributions expected for the years 2020, 2050, and 2080 under a single simulated climatic scenario. Our analysis suggests that some climatic groups of Aspidoscelis costata costata will exhibit reductions and in others expansions in their distribution, with potential upward shifts toward higher elevation in response to climate warming. Different climatic groups were revealed in our analysis that subsequently showed heterogeneous responses to climatic change illustrating the complex nature of species geographic responses to environmental change and the importance of modeling climatic or geographic groups and/or populations instead of the entire species' range treated as a homogeneous entity. PMID:23215975

Güizado-Rodríguez, Martha Anahí; Ballesteros-Barrera, Claudia; Casas-Andreu, Gustavo; Barradas-Miranda, Victor Luis; Téllez-Valdés, Oswaldo; Salgado-Ugarte, Isaías Hazarmabeth

2012-12-01

117

The Changing Geographic Distribution of Malaria with Global Climate Warming  

NSDL National Science Digital Library

In this exercise, students analyze climate data to find areas in the southern United States that are now close to having conditions in which the malaria parasite and its mosquito hosts thrive and then attempt to forecast when areas might become climatically suitable.

Mary Savina

118

Climate Variability and Dengue Fever in Warm and Humid Mexico  

PubMed Central

Multiple linear regression models were fitted to look for associations between changes in the incidence rate of dengue fever and climate variability in the warm and humid region of Mexico. Data were collected for 12 Mexican provinces over a 23-year period (January 1985 to December 2007). Our results show that the incidence rate or risk of infection is higher during El Niño events and in the warm and wet season. We provide evidence to show that dengue fever incidence was positively associated with the strength of El Niño and the minimum temperature, especially during the cool and dry season. Our study complements the understanding of dengue fever dynamics in the region and may be useful for the development of early warning systems. PMID:21540386

Colón-González, Felipe J.; Lake, Iain R.; Bentham, Graham

2011-01-01

119

Political Polarization over Global Warming: Analyzing Twitter Data on Climate Change  

E-print Network

Political Polarization over Global Warming: Analyzing Twitter Data on Climate Change Alireza/Democrats are more likely to ex- press personal concern about global warming than are self-identified conservatives

Sukthankar, Gita Reese

120

Multisectoral climate impact hotspots in a warming world.  

PubMed

The impacts of global climate change on different aspects of humanity's diverse life-support systems are complex and often difficult to predict. To facilitate policy decisions on mitigation and adaptation strategies, it is necessary to understand, quantify, and synthesize these climate-change impacts, taking into account their uncertainties. Crucial to these decisions is an understanding of how impacts in different sectors overlap, as overlapping impacts increase exposure, lead to interactions of impacts, and are likely to raise adaptation pressure. As a first step we develop herein a framework to study coinciding impacts and identify regional exposure hotspots. This framework can then be used as a starting point for regional case studies on vulnerability and multifaceted adaptation strategies. We consider impacts related to water, agriculture, ecosystems, and malaria at different levels of global warming. Multisectoral overlap starts to be seen robustly at a mean global warming of 3 °C above the 1980-2010 mean, with 11% of the world population subject to severe impacts in at least two of the four impact sectors at 4 °C. Despite these general conclusions, we find that uncertainty arising from the impact models is considerable, and larger than that from the climate models. In a low probability-high impact worst-case assessment, almost the whole inhabited world is at risk for multisectoral pressures. Hence, there is a pressing need for an increased research effort to develop a more comprehensive understanding of impacts, as well as for the development of policy measures under existing uncertainty. PMID:24344270

Piontek, Franziska; Müller, Christoph; Pugh, Thomas A M; Clark, Douglas B; Deryng, Delphine; Elliott, Joshua; Colón González, Felipe de Jesus; Flörke, Martina; Folberth, Christian; Franssen, Wietse; Frieler, Katja; Friend, Andrew D; Gosling, Simon N; Hemming, Deborah; Khabarov, Nikolay; Kim, Hyungjun; Lomas, Mark R; Masaki, Yoshimitsu; Mengel, Matthias; Morse, Andrew; Neumann, Kathleen; Nishina, Kazuya; Ostberg, Sebastian; Pavlick, Ryan; Ruane, Alex C; Schewe, Jacob; Schmid, Erwin; Stacke, Tobias; Tang, Qiuhong; Tessler, Zachary D; Tompkins, Adrian M; Warszawski, Lila; Wisser, Dominik; Schellnhuber, Hans Joachim

2014-03-01

121

Midlatitude Ocean-Atmosphere Interactions in a Warming Climate  

NASA Astrophysics Data System (ADS)

Recent studies have shown that mid-latitude regions with strong SST gradients as they can be found in the Gulf Stream and it's extension are a key-region for midlatitude ocean-atmosphere interactions; SST variability on inter-annual to decadal timescales in this region has a distinct impact on the overlying atmosphere. Climate projections with coupled general circulation models show strong indications, that the strength and the shape of the ocean circulation might underly crucial changes in a warming climate. This work presents an analysis of the atmospheric part of a long-term (covering the period until 2300) RCP 8.5 scenario run of a coupled general circulation model (MPI-ESM-LR) with focus on the North Atlantic. The ocean component of the model shows a strong decrease in the meridional overturning circulation and a northward-shift of the boundary between the subpolar and the subtropical gyre. This leads to significant changes of the ocean surface conditions in the Gulf Stream and the Gulf Stream extension. The weakened MOC and the northward shift of the SST front leads to a weakening of the SST gradients in the historical Gulf Stream area and a strengthening of the gradients east of Newfoundland. We analysed the impact of the changes in the ocean on precipitation, a quantity which has been shown to be highly sensitive to the position of the SST front and the absolute value of SST in that region in previous studies. In winter the model shows a large region with strongly enhanced precipitation southeast off Newfoundland, likely related to a slight intensification of the North-Atlantic storm track present in the future projection. In summer the most prominent feature in terms of precipitation is a decrease in the region off the US east coast, where the historical control experiment had the strongest SST gradients, but shows weaker gradients in the future. A preliminary analysis of the hydrological cycle gives indications, that the precipitation changes are induced by a combination of (globally) warmer air temperatures enhancing the hydrological cycle and an effect due to shifted ocean surface patterns. Sensitivity experiments with the atmospheric component of the model are being performed to separate and quantify these two effects better.

Hand, Ralf; Keenlyside, Noel S.; Greatbatch, Richard J.; Omrani, Nour-Eddine

2014-05-01

122

Climatic factors controlling plant sensitivity to warming Andrei Lapenis & Hugh Henry & Mathias Vuille &  

E-print Network

, these longer thermal growing seasons may not be beneficial for plant growth. Climatic Change (2014) 122Climatic factors controlling plant sensitivity to warming Andrei Lapenis & Hugh Henry & Mathias, plants managed to keep pace with climate warming by shifting their leafing and flowering events

Vuille, Mathias

123

A Review of the Practical Problems Resulting from the Impact of the Climate Warming on Birds  

Microsoft Academic Search

In the article attention is focussed on the aspects of the effect of climate change on bird protection, aviation flight safety, and certain branches of economy. Changes in habitats under the climate warming exert influence on bird breeding success, breeding ranges, and, finally, the effectiveness of bird conservation. Under the impact of climate warming, changes in migratory state, migration routes,

Me?islovas Žalakevi?ius

2001-01-01

124

Measure Guideline: Supplemental Dehumidification in Warm-Humid Climates  

SciTech Connect

This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. In older homes in warm-humid climates, cooling loads are typically high and cooling equipment runs a lot to cool the air. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisture being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and some winter days. In warm-humid climates, those long off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and avoids adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.

Rudd, A.

2014-10-01

125

Trophic level responses differ as climate warms in Ireland.  

PubMed

Effective ecosystem functioning relies on successful species interaction. However, this delicate balance may be disrupted if species do not respond to environmental change at a similar rate. Here we examine trends in the timing of spring phenophases of groups of species occupying three trophic levels as a potential indicator of ecosystem response to climate warming in Ireland. The data sets were of varying length (1976-2009) and from varying locations: (1) timing of leaf unfolding and May Shoot of a range of broadleaf and conifer tree species, (2) first appearance dates of a range of moth species, and (3) first arrival dates of a range of spring migrant birds. All three groups revealed a statistically significant (P<0.01 and P<0.001) advance in spring phenology that was driven by rising spring temperature (P<0.05; 0.45 °C /decade). However, the rate of advance was greater for moths (1.8 days/year), followed by birds (0.37 days/year) and trees (0.29 days/year). In addition, the length of time between (1) moth emergence and leaf unfolding and (2) moth emergence and bird arrival decreased significantly (P<0.05 and P<0.001, respectively), indicating a decrease in the timing between food supply and demand. These differing trophic level response rates demonstrate the potential for a mismatch in the timing of interdependent phenophases as temperatures rise. Even though these data were not specifically collected to examine climate warming impacts, we conclude that such data may be used as an early warning indicator and as a means to monitor the potential for future ecosystem disruption to occur as climate warms. PMID:25380974

Donnelly, Alison; Yu, Rong; Liu, Lingling

2014-11-01

126

The effect of slope aspect on the response of snowpack to climate warming in the Pyrenees  

NASA Astrophysics Data System (ADS)

The aim of this study was to analyse the effect of slope aspect on the response of snowpack to climate warming in the Pyrenees. For this purpose, data available from five automatic weather stations were used to simulate the energy and mass balance of snowpack, assuming different magnitudes of an idealized climate warming (upward shifting of 1, 2 and 3 °C the temperature series). Snow energy and mass balance were simulated using the Cold Regions Hydrological Modelling platform (CRHM). CRHM was used to create a model that enabled correction of the all-wave incoming radiation fluxes from the observation sites for various slope aspects (N, NE, E, SE, S, SW,W,NW and flat areas), which enabled assessment of the differential impact of climate warming on snow processes on mountain slopes. The results showed that slope aspect was responsible for substantial variability in snow accumulation and the duration of the snowpack. Simulated variability markedly increased with warmer temperature conditions. Annual maximum snow accumulation (MSA) and annual snowpack duration (ASD) showed marked sensitivity to a warming of 1 °C. Thus, the sensitivity of the MSA in flat areas ranged from 11 to 17 % per degree C amongst the weather stations, and the ASD ranged from 11 to 20 days per degree C. There was a clear increase in the sensitivity of the snowpack to climate warming on those slopes that received intense solar radiation (S, SE and SW slopes) compared with those slopes where the incident radiation was more limited (N, NE and NW slopes). The sensitivity of the MSA and the ASD increased as the temperature increased, particularly on the most irradiated slopes. Large interannual variability was also observed. Thus, with more snow accumulation and longer duration the sensitivity of the snowpack to temperature decreased, especially on south-facing slopes.

López-Moreno, J. I.; Revuelto, J.; Gilaberte, M.; Morán-Tejeda, E.; Pons, M.; Jover, E.; Esteban, P.; García, C.; Pomeroy, J. W.

2014-07-01

127

Climate warming and agricultural stressors interact to determine stream periphyton community composition.  

PubMed

Lack of knowledge about how the various drivers of global climate change will interact with multiple stressors already affecting ecosystems is the basis for great uncertainty in projections of future biological change. Despite concerns about the impacts of changes in land use, eutrophication and climate warming in running waters, the interactive effects of these stressors on stream periphyton are largely unknown. We manipulated nutrients (simulating agricultural runoff), deposited fine sediment (simulating agricultural erosion) (two levels each) and water temperature (eight levels, 0-6 °C above ambient) simultaneously in 128 streamside mesocosms. Our aim was to determine the individual and combined effects of the three stressors on the algal and bacterial constituents of the periphyton. All three stressors had pervasive individual effects, but in combination frequently produced synergisms at the population level and antagonisms at the community level. Depending on sediment and nutrient conditions, the effect of raised temperature frequently produced contrasting response patterns, with stronger or opposing effects when one or both stressors were augmented. Thus, warming tended to interact negatively with nutrients or sediment by weakening or reversing positive temperature effects or strengthening negative ones. Five classes of algal growth morphology were all affected in complex ways by raised temperature, suggesting that these measures may prove unreliable in biomonitoring programs in a warming climate. The evenness and diversity of the most abundant bacterial taxa increased with temperature at ambient but not with enriched nutrient levels, indicating that warming coupled with nutrient limitation may lead to a more evenly distributed bacterial community as temperatures rise. Freshwater management decisions that seek to avoid or mitigate the negative effects of agricultural land use on stream periphyton should be informed by knowledge of the interactive effects of multiple stressors in a warming climate. PMID:24942814

Piggott, Jeremy J; Salis, Romana K; Lear, Gavin; Townsend, Colin R; Matthaei, Christoph D

2015-01-01

128

Typhoon and storm surge intensity changes under the warming climate around Korean Peninsula  

NASA Astrophysics Data System (ADS)

This study investigates the intensity change in typhoons and storm surges surrounding the Korean Peninsula under global warming conditions as obtained from the MPI_ECHAM5 climate model using the A1B series. The authors use the Cyclostationary Empirical Orthogonal Function to estimate future background fields for typhoon simulations from twenty-first-century prediction results. A series of numerical experiments applies WRF (Weather Research and Forecasting) and POM (Prinston Ocean Model) models to simulate two historical typhoons, Maemi (2003) and Rusa (2002), and associated storm surges under real historical and future warming conditions. Applying numerical experiments to two typhoons, this study found that their central pressure dropped about 19 and 17 hPa, respectively, when considering the future sea surface temperature (a warming of 3.9 K for 100 years) over the East China Sea (Exp. 1). The associated enhancement of storm surge height ranged from 16 to 67 cm along the southern coast of the Korean Peninsula. However, when the study considered global warming conditions for other atmospheric variables such as sea-level pressure, air temperature, relative humidity, geopotential height, and wind in the typhoon simulations (Exp. 2), the intensities of the two typhoons and their associated surge heights scarcely increased compared to the results of Exp. 1. Analyzing projected atmospheric variables, the authors found that air temperatures at the top of the storm around 200 hPa increased more than those at the surface in tropical and mid-latitudes. The reduced vertical temperature difference provided an unfavorable condition in the typhoon's development even under conditions of global warming. This suggests that global warming may not always correlate with a large increase in the number of intense cyclones and/or an increase in associated storm surges.

Oh, Sang Myeong; Moon, Il-Ju

2014-05-01

129

Vertical gradient of climate change and climate tourism conditions in the Black Forest.  

PubMed

Due to the public discussion about global and regional warming, the regional climate and the modified climate conditions are analyzed exemplarily for three different regions in the southern Black Forest (southwest Germany). The driving question behind the present study was how can tourism adapt to modified climate conditions and associated changes to the tourism potential in low mountain ranges. The tourism potential is predominately based on the attractiveness of natural resources being climate-sensitive. In this study, regional climate simulations (A1B) are analyzed by using the REMO model. To analyze the climatic tourism potential, the following thermal, physical and aesthetic parameters are considered for the time span 1961-2050: thermal comfort, heat and cold stress, sunshine, humid-warm conditions (sultriness), fog, precipitation, storm, and ski potential (snow cover). Frequency classes of these parameters expressed as a percentage are processed on a monthly scale. The results are presented in form of the Climate-Tourism-Information-Scheme (CTIS). Due to warmer temperatures, winters might shorten while summers might lengthen. The lowland might be more affected by heat and sultriness (e.g., Freiburg due to the effects of urban climate). To adapt to a changing climate and tourism, the awareness of both stakeholders and tourists as well as the adaptive capability are essential. PMID:19705164

Endler, Christina; Oehler, Karoline; Matzarakis, Andreas

2010-01-01

130

Vertical gradient of climate change and climate tourism conditions in the Black Forest  

NASA Astrophysics Data System (ADS)

Due to the public discussion about global and regional warming, the regional climate and the modified climate conditions are analyzed exemplarily for three different regions in the southern Black Forest (southwest Germany). The driving question behind the present study was how can tourism adapt to modified climate conditions and associated changes to the tourism potential in low mountain ranges. The tourism potential is predominately based on the attractiveness of natural resources being climate-sensitive. In this study, regional climate simulations (A1B) are analyzed by using the REMO model. To analyze the climatic tourism potential, the following thermal, physical and aesthetic parameters are considered for the time span 1961-2050: thermal comfort, heat and cold stress, sunshine, humid-warm conditions (sultriness), fog, precipitation, storm, and ski potential (snow cover). Frequency classes of these parameters expressed as a percentage are processed on a monthly scale. The results are presented in form of the Climate-Tourism-Information-Scheme (CTIS). Due to warmer temperatures, winters might shorten while summers might lengthen. The lowland might be more affected by heat and sultriness (e.g., Freiburg due to the effects of urban climate). To adapt to a changing climate and tourism, the awareness of both stakeholders and tourists as well as the adaptive capability are essential.

Endler, Christina; Oehler, Karoline; Matzarakis, Andreas

2010-01-01

131

Effects Of Climate, Permafrost And Fire On Potential Vegetation Change In Siberia In A Warming Climate  

Microsoft Academic Search

Observations and general circulation model projections suggest significant temperature increases in Siberia this century, which are expected to have profound effects on Siberian vegetation. Increased permafrost melt and forest fire directly affected by climate warming are predicted to additionally influence vegetation change. Our goal is to model potential vegetation change across Siberia (within the territory between the Urals and Yakutia

N. M. Tchebakova; E. I. Parfenova; A. J. Soja

2008-01-01

132

Weakening of atmospheric information flow in a warming climate in the Community Climate System Model  

NASA Astrophysics Data System (ADS)

We introduce a new perspective of climate change by revealing the changing characteristics of atmospheric information flow in a warming climate. The key idea is to interpret large-scale atmospheric dynamical processes as information flow around the globe and to identify the pathways of this information flow using a climate network based on causal discovery and graphical models. We construct such networks using the daily geopotential height data from the Community Climate System Model Version 4.0 (CCSM4.0)'s 20th century climate simulation and 21st century climate projection. We show that in the CCSM4.0 model under enhanced greenhouse gases (GHGs) forcing, prominent midlatitude information pathways in the midtroposphere weaken and shift poleward, while major tropical information pathways start diminishing. Averaged over the entire Northern Hemisphere, the atmospheric information flow weakens. The implications of this weakening for the interconnectivity among different geographical locations and for the intrinsic predictability of the atmosphere are discussed.

Deng, Yi; Ebert-Uphoff, Imme

2014-01-01

133

Implications of global warming for the climate of African rainforests.  

PubMed

African rainforests are likely to be vulnerable to changes in temperature and precipitation, yet there has been relatively little research to suggest how the regional climate might respond to global warming. This study presents projections of temperature and precipitation indices of relevance to African rainforests, using global climate model experiments to identify local change as a function of global temperature increase. A multi-model ensemble and two perturbed physics ensembles are used, one with over 100 members. In the east of the Congo Basin, most models (92%) show a wet signal, whereas in west equatorial Africa, the majority (73%) project an increase in dry season water deficits. This drying is amplified as global temperature increases, and in over half of coupled models by greater than 3% per °C of global warming. Analysis of atmospheric dynamics in a subset of models suggests that this could be partly because of a rearrangement of zonal circulation, with enhanced convection in the Indian Ocean and anomalous subsidence over west equatorial Africa, the Atlantic Ocean and, in some seasons, the Amazon Basin. Further research to assess the plausibility of this and other mechanisms is important, given the potential implications of drying in these rainforest regions. PMID:23878329

James, Rachel; Washington, Richard; Rowell, David P

2013-01-01

134

Aridity changes in the Tibetan Plateau in a warming climate  

NASA Astrophysics Data System (ADS)

Desertification in the Tibetan Plateau (TP) has drawn increasing attention in the recent decades. It has been postulated as a consequence of increasing climate aridity due to the observed warming. This study quantifies the aridity changes in the TP and attributes the changes to different climatic factors. Using the ratio of precipitation to potential evapotranspiration (P/PET) as an aridity index, we used observed meteorological records at 83 stations in the TP to calculate PET using the Penman–Monteith algorithm and the ratio. Spatial and temporal changes of P/PET in 1979–2011 were analyzed. Results show that stations located in the arid and semi-arid northwestern TP are becoming significantly wetter, and half of the stations in the semi-humid eastern TP are becoming drier, though not significantly, in the recent three decades. The aridity change patterns are significantly correlated with the change patterns of precipitation, sunshine duration and diurnal temperature range. Temporal correlations between the annual P/PET ratio and other meteorological variables confirm the significant correlation between aridity and the three variables, with precipitation being the dominant driver of P/PET changes at the interannual time scale. Annual PET are insignificantly but negatively correlated with P/PET in the cold season. In the warm season, however, the correlation between PET and P/PET is significant at the confidence level of 99.9% when the cryosphere near the surface melts. Significant correlation between annual wind speed and aridity occurs in limited locations and months. Consistency in the climatology pattern and linear trends in surface air temperature and precipitation calculated using station data, gridded data, and nearest grid-to-stations for the TP average and across sub-basins indicate the robustness of the trends despite the large spatial heterogeneity in the TP that challenge climate monitoring.

Gao, Yanhong; Li, Xia; Leung, L. Ruby; Chen, Deliang; Xu, Jianwei

2015-03-01

135

Multisectoral climate impact hotspots in a warming world  

PubMed Central

The impacts of global climate change on different aspects of humanity’s diverse life-support systems are complex and often difficult to predict. To facilitate policy decisions on mitigation and adaptation strategies, it is necessary to understand, quantify, and synthesize these climate-change impacts, taking into account their uncertainties. Crucial to these decisions is an understanding of how impacts in different sectors overlap, as overlapping impacts increase exposure, lead to interactions of impacts, and are likely to raise adaptation pressure. As a first step we develop herein a framework to study coinciding impacts and identify regional exposure hotspots. This framework can then be used as a starting point for regional case studies on vulnerability and multifaceted adaptation strategies. We consider impacts related to water, agriculture, ecosystems, and malaria at different levels of global warming. Multisectoral overlap starts to be seen robustly at a mean global warming of 3 °C above the 1980–2010 mean, with 11% of the world population subject to severe impacts in at least two of the four impact sectors at 4 °C. Despite these general conclusions, we find that uncertainty arising from the impact models is considerable, and larger than that from the climate models. In a low probability-high impact worst-case assessment, almost the whole inhabited world is at risk for multisectoral pressures. Hence, there is a pressing need for an increased research effort to develop a more comprehensive understanding of impacts, as well as for the development of policy measures under existing uncertainty. PMID:24344270

Piontek, Franziska; Müller, Christoph; Pugh, Thomas A. M.; Clark, Douglas B.; Deryng, Delphine; Elliott, Joshua; Colón González, Felipe de Jesus; Flörke, Martina; Folberth, Christian; Franssen, Wietse; Frieler, Katja; Friend, Andrew D.; Gosling, Simon N.; Hemming, Deborah; Khabarov, Nikolay; Kim, Hyungjun; Lomas, Mark R.; Masaki, Yoshimitsu; Mengel, Matthias; Morse, Andrew; Neumann, Kathleen; Nishina, Kazuya; Ostberg, Sebastian; Pavlick, Ryan; Ruane, Alex C.; Schewe, Jacob; Schmid, Erwin; Stacke, Tobias; Tang, Qiuhong; Tessler, Zachary D.; Tompkins, Adrian M.; Warszawski, Lila; Wisser, Dominik; Schellnhuber, Hans Joachim

2014-01-01

136

Climate warming could shift the timing of seed germination in alpine plants  

PubMed Central

Background and Aims Despite the considerable number of studies on the impacts of climate change on alpine plants, there have been few attempts to investigate its effect on regeneration. Recruitment from seeds is a key event in the life-history of plants, affecting their spread and evolution and seasonal changes in climate will inevitably affect recruitment success. Here, an investigation was made of how climate change will affect the timing and the level of germination in eight alpine species of the glacier foreland. Methods Using a novel approach which considered the altitudinal variation of temperature as a surrogate for future climate scenarios, seeds were exposed to 12 different cycles of simulated seasonal temperatures in the laboratory, derived from measurements at the soil surface at the study site. Key Results Under present climatic conditions, germination occurred in spring, in all but one species, after seeds had experienced autumn and winter seasons. However, autumn warming resulted in a significant increase in germination in all but two species. In contrast, seed germination was less sensitive to changes in spring and/or winter temperatures, which affected only three species. Conclusions Climate warming will lead to a shift from spring to autumn emergence but the extent of this change across species will be driven by seed dormancy status. Ungerminated seeds at the end of autumn will be exposed to shorter winter seasons and lower spring temperatures in a future, warmer climate, but these changes will only have a minor impact on germination. The extent to which climate change will be detrimental to regeneration from seed is less likely to be due to a significant negative effect on germination per se, but rather to seedling emergence in seasons that the species are not adapted to experience. Emergence in autumn could have major implications for species currently adapted to emerge in spring. PMID:22596094

Mondoni, Andrea; Rossi, Graziano; Orsenigo, Simone; Probert, Robin J.

2012-01-01

137

Modeling Multi-Reservoir Hydropower Systems in the Sierra Nevada with Environmental Requirements and Climate Warming  

NASA Astrophysics Data System (ADS)

Hydropower systems and other river regulation often harm instream ecosystems, partly by altering the natural flow and temperature regimes that ecosystems have historically depended on. These effects are compounded at regional scales. As hydropower and ecosystems are increasingly valued globally due to growing values for clean energy and native species as well as and new threats from climate warming, it is important to understand how climate warming might affect these systems, to identify tradeoffs between different water uses for different climate conditions, and to identify promising water management solutions. This research uses traditional simulation and optimization to explore these issues in California's upper west slope Sierra Nevada mountains. The Sierra Nevada provides most of the water for California's vast water supply system, supporting high-elevation hydropower generation, ecosystems, recreation, and some local municipal and agricultural water supply along the way. However, regional climate warming is expected to reduce snowmelt and shift runoff to earlier in the year, affecting all water uses. This dissertation begins by reviewing important literature related to the broader motivations of this study, including river regulation, freshwater conservation, and climate change. It then describes three substantial studies. First, a weekly time step water resources management model spanning the Feather River watershed in the north to the Kern River watershed in the south is developed. The model, which uses the Water Evaluation And Planning System (WEAP), includes reservoirs, run-of-river hydropower, variable head hydropower, water supply demand, and instream flow requirements. The model is applied with a runoff dataset that considers regional air temperature increases of 0, 2, 4 and 6 °C to represent historical, near-term, mid-term and far-term (end-of-century) warming. Most major hydropower turbine flows are simulated well. Reservoir storage is also generally well simulated, mostly limited by the accuracy of inflow hydrology. System-wide hydropower generation is reduced by 9% with 6 °C warming. Most reductions in hydropower generation occur in the highly productive watersheds in the northern Sierra Nevada. The central Sierra Nevada sees less reduction in annual runoff and can adapt better to changes in runoff timing. Generation in southern watersheds is expected to decrease. System-wide, reservoirs adapt to capture earlier runoff, but mostly decrease in mean reservoir storage with warming due to decreasing annual runoff. Second, a multi-reservoir optimization model is developed using linear programming that considers the minimum instream flows (MIFs) and weekly down ramp rates (DRRs) in the Upper Yuba River in the northern Sierra Nevada. Weekly DRR constraints are used to mimic spring snowmelt flows, which are particularly important for downstream ecosystems in the Sierra Nevada but are currently missing due to the influence of dams. Trade-offs between MIFs, DRRs and hydropower are explored with air temperature warming (+0, 2, 4 and 6 °C). Under base case operations, mean annual hydropower generation increases slightly with 2 °C warming and decreases slightly with 6 °C warming. With 6 °C warming, the most ecologically beneficial MIF and DRR reduce hydropower generation 5.5% compared to base case operations and a historical climate, which has important implications for re-licensing the hydropower project. Finally, reservoir management for downstream temperatures is explored using a linear programming model to optimally release water from a reservoir using selective withdrawal. The objective function is to minimize deviations from desired downstream temperatures, which are specified to mimic the natural temperature regime in the river. One objective of this study was to develop a method that can be readily integrated into a basin-scale multi-reservoir optimization model using a network representation of system features. The second objective was to explore the potential use of reservoirs to maintain an ideal str

Rheinheimer, David Emmanuel

138

Changes in ecologically critical terrestrial climate conditions.  

PubMed

Terrestrial ecosystems have encountered substantial warming over the past century, with temperatures increasing about twice as rapidly over land as over the oceans. Here, we review the likelihood of continued changes in terrestrial climate, including analyses of the Coupled Model Intercomparison Project global climate model ensemble. Inertia toward continued emissions creates potential 21st-century global warming that is comparable in magnitude to that of the largest global changes in the past 65 million years but is orders of magnitude more rapid. The rate of warming implies a velocity of climate change and required range shifts of up to several kilometers per year, raising the prospect of daunting challenges for ecosystems, especially in the context of extensive land use and degradation, changes in frequency and severity of extreme events, and interactions with other stresses. PMID:23908225

Diffenbaugh, Noah S; Field, Christopher B

2013-08-01

139

Why are climate models reproducing the observed global surface warming so well?  

E-print Network

Why are climate models reproducing the observed global surface warming so well? Reto Knutti1 global surface warming so well?, Geophys. Res. Lett., 35, L18704, doi:10.1029/ 2008GL034932. 1 models reproduce the observed surface warming better than one would expect given the uncertainties

Fischlin, Andreas

140

Climate feedback analysis of the GFDL IPCC AR4 global warming simulation  

Microsoft Academic Search

Both observed and modeled global warming pattern shows a large surface polar warming and a large upper atmospheric warming in the tropics. This pattern leads to an amplification (reduction) of the temperature gradient at upper levels (surface). Physical processes behind this temperature change are the external radiative forcing, and subsequent feedback processes that may amplify or dampen the climate response.

Christelle Clemence Castet

2009-01-01

141

A Vast Machine Computer Models, Climate Data, and the Politics of Global Warming  

E-print Network

A Vast Machine Computer Models, Climate Data, and the Politics of Global Warming Paul N. Edwards models, climate data, and the politics of global warming / Paul N. Edwards. p. cm. Includes. Climatology--History. 3. Meteorology--History. 4. Climatology--Technological innovation. 5. Global temperature

142

Territorial Manifestations of the Economical Influence Areas of Global Warming and Climate Change  

Microsoft Academic Search

Economic space is structured by the relationship between the anthropogenic and economic factors, with a dynamical evolution defined by the financial flows around the world and technology evolution. The global warming and the climate change are two different processes associated on the planet, due to different etiologies: the global warming is produced principally by anthropogenic effects, whereas the climate change

Y. G. Garcia Lopez; J. A. Perez-Peraza; V. M. Velasco Herrera

2007-01-01

143

Response of global warming on regional climate change over Korea: An experiment with the MM5 model  

Microsoft Academic Search

This study is to investigate changes in regional surface climate arising from global warming with MM5 downscaling simulation for the period 1971–2100. The main focus is on the drought conditions over Korea. Palmer Drought Severity Index (PDSI) is utilized as a measure of drought severity. The important findings show the increase of surface air temperature by 6°C and precipitation by

Kyung-On Boo; Won-Tae Kwon; Jai-Ho Oh; Hee-Jeong Baek

2004-01-01

144

Response of global warming on regional climate change over Korea: An experiment with the MM5 model  

Microsoft Academic Search

This study is to investigate changes in regional surface climate arising from global warming with MM5 downscaling simulation for the period 1971-2100. The main focus is on the drought conditions over Korea. Palmer Drought Severity Index (PDSI) is utilized as a measure of drought severity. The important findings show the increase of surface air temperature by 6°C and precipitation by

Kyung-On Boo; Won-Tae Kwon; Jai-Ho Oh; Hee-Jeong Baek

2004-01-01

145

Geoengineering the Climate: Approaches to Counterbalancing Global Warming  

NASA Astrophysics Data System (ADS)

For the past two hundred years, the inadvertent release of carbon dioxide and other radiatively active gases and aerosols, particularly as a result of combustion of fossil fuels and changes in land cover, have been contributing to global climate change. Global warming to date is approaching 1°C, and this is being accompanied by reduced sea ice, rising sea level, shifting ecosystems and more. Rather than sharply curtailing use of fossil fuels in order to reduce CO2 emissions and eventually eliminate the net human influence on global climate, a number of approaches have been suggested that are intended to advertently modify the climate in a manner to counter-balance the warming influence of greenhouse gas emissions. One general type of approach is carbon sequestration, which focuses on capturing the CO2 and then sequestering it underground or in the ocean. This can be done at the source of emission, by pulling the CO2 out of the atmosphere through some chemical process, or by enhancing the natural processes that remove CO2 from the atmosphere, for example by fertilizing the oceans with iron. A second general approach to geoengineering the climate is to lower the warming influence of the incoming solar radiation by an amount equivalent to the energy captured by the CO2-induced enhancement of the greenhouse effect. Proposals have been made to do this by locating a deflector at the Earth-Sun Lagrange point, lofting many thousands of near-Earth mirrors, injecting aerosols into the stratosphere, or by increasing the surface albedo. A third general approach is to alter natural Earth system processes in ways that would counterbalance the effects of the warming. Among suggested approaches are constructing dams to block various ocean passages, oceanic films to limit evaporation and water vapor feedback, and even, at small scale, to insulate mountain glaciers to prevent melting. Each of these approaches has its advantages, ranging from simplicity to reversibility, and disadvantages, ranging from costs for implementation to associated inadvertent negative environmental consequences. Unless implemented as only a bridging effort, geoengineering would require diversion of substantial, and even growing, resources from the effort to move away from reliance on fossil fuels. Because the lifetime of the excess CO2 in the atmosphere is so long, such efforts would generally need to be maintained for centuries by future generations to avoid a relatively rapid increase in global average temperature, even after emissions of CO2 had eventually been halted. In that such approaches are also fraught with uncertainties, there has been very little study of the details of how such approaches might be pursued and of their overall advertent and inadvertent consequences, leaving the area open to ongoing consideration of sometimes rather speculative possibilities.

MacCracken, M. C.

2005-12-01

146

Unexpected response of high Alpine Lake waters to climate warming.  

PubMed

Over the past two decades, we have observed a substantial rise in solute concentration at two remote high mountain lakes in catchments of metamorphic rocks in the European Alps. At Rasass See, the electrical conductivity increased 18-fold. Unexpectedly high nickel concentrations at Rasass See, which exceeded the limit in drinking water by more than 1 order of magnitude, cannot be related to catchment geology. We attribute these changes in lake water quality to solute release from the ice of an active rock glacier in the catchment as a response to climate warming. Similar processes occurred at the higher elevation lake Schwarzsee ob Sölden, where electrical conductivity has risen 3-fold during the past two decades. PMID:18044521

Thies, Hansjörg; Nickus, Ulrike; Mair, Volkmar; Tessadri, Richard; Tait, Danilo; Thaler, Bertha; Psenner, Roland

2007-11-01

147

Climate Change over the Equatorial Indo-Pacific in Global Warming* CHIE IHARA, YOCHANAN KUSHNIR, AND MARK A. CANE  

E-print Network

Climate Change over the Equatorial Indo-Pacific in Global Warming* CHIE IHARA, YOCHANAN KUSHNIR to global warming is investigated using model outputs submitted to the Intergovernmental Panel on Climate equatorial Indian Ocean warm more than the SSTs in the eastern equatorial Indian Ocean under global warming

148

Climate warming and estuarine and marine coastal ecosystems  

SciTech Connect

Estuaries are physically controlled, resilient coastal ecosystems harboring environmentally tolerant species in diluted seawater. Marine coastal systems are less stressed physically and contain some environmentally less tolerant species. Both systems are biologically productive and economically significant. Because of their complex structure and function, it is difficult to predict accurately the effects of climate change, but some broad generalizations can be made. If climate warming occurs, it will raise sea-level, heat shallow waters, and modify precipitation, wind, and water circulation patterns. Rapid sea-level rise could cause the loss of salt marshes, mangrove swamps, and coral reefs, thus diminishing the ecological roles of these highly productive systems. Warmer waters could eliminate heat-sensitive species from part of their geographical range while allowing heat-tolerant species to expand their range, depending on their ability to disperse. Most thermally influenced losses of species will probably only be local, but changed distributions may lead to changed community function. It is more difficult to predict the effects of modified precipitation, wind, and water circulation patterns, but changes could affect organisms dependent on such patterns for food production (e.g., in upwelling regions) or for retention in estuaries. Aquacultural and fishery-related enterprises would be affected negatively in some regions and positively in others. 73 refs.

Kennedy, V.S. [Univ. of Maryland Center for Environmental and Estuarine Studies, Cambridge, MD (United States). Horn Point Environmental Lab.

1994-12-31

149

Impact of climate change on stratospheric sudden warmings as simulated by the  

E-print Network

Impact of climate change on stratospheric sudden warmings as simulated by the Canadian middle midwinter stratospheric sudden warmings (SSWs) are ex- amined using transient climate change simulations$593157392 CentAUR 7326E125C427E3E3C7E84272B43&E#E97D4$ 97D4$4BE27B725CE9393BE647 #12;Impact of Climate Change

Wirosoetisno, Djoko

150

Global warming vs. climate change, taxes vs. prices: Does word choice matter?  

Microsoft Academic Search

Does “climate change” seem like a less serious problem than “global warming” to Americans and Europeans? Does describing the\\u000a costs of climate change mitigation in terms of “higher taxes” instead of “higher prices” reduce public support for such efforts?\\u000a In an experiment embedded in an American national survey, respondents were randomly assigned to rate the seriousness of “global\\u000a warming,” “climate

Ana Villar; Jon A. Krosnick

2011-01-01

151

Energetic contribution potential of building-integrated photovoltaics on airports in warm climates  

SciTech Connect

Especially in warm climates, a considerable fraction of the electricity demand in commercial buildings is due to the intensive use of air-conditioning systems. Airport buildings in sunny and warm regions present a perfect match between energy demand and solar resource availability. Airport buildings are also typically large and horizontal, isolated and free of shading, and have a great potential for the integration of solar photovoltaic (PV) systems. In this work, we assess the potential impact in energy demand reduction at the Florianopolis International Airport in Brazil (27 S, 48 W) with the use of building-integrated photovoltaic (BIPV) systems. We analyse the building's hourly energy consumption and solar irradiation data, to assess the match between energy demand and potential generation, and we estimate the PV power necessary to supply both the total amount and fractions of the annual energy demand. Our results show that the integration of PV systems on airport buildings in warm climates can supply the entire electric power consumption of an airport complex, in line with the general concept of a zero-energy building (ZEB). (author)

Ruether, Ricardo [LabEEE - Laboratorio de Eficiencia Energetica em Edificacoes, UFSC - Universidade Federal de Santa Catarina, Caixa Postal 476, Florianopolis, SC 88040-900 (Brazil); LABSOLAR - Laboratorio de Energia Solar, UFSC - Universidade Federal de Santa Catarina, Caixa Postal 476, Florianopolis, SC 88040-900 (Brazil); Braun, Priscila [LabEEE - Laboratorio de Eficiencia Energetica em Edificacoes, UFSC - Universidade Federal de Santa Catarina, Caixa Postal 476, Florianopolis, SC 88040-900 (Brazil)

2009-10-15

152

Disparity in elevational shifts of European trees in response to recent climate warming.  

PubMed

Predicting climate-driven changes in plant distribution is crucial for biodiversity conservation and management under recent climate change. Climate warming is expected to induce movement of species upslope and towards higher latitudes. However, the mechanisms and physiological processes behind the altitudinal and latitudinal distribution range of a tree species are complex and depend on each tree species features and vary over ontogenetic stages. We investigated the altitudinal distribution differences between juvenile and adult individuals of seven major European tree species along elevational transects covering a wide latitudinal range from southern Spain (37°N) to northern Sweden (67°N). By comparing juvenile and adult distributions (shifts on the optimum position and the range limits) we assessed the response of species to present climate conditions in relation to previous conditions that prevailed when adults were established. Mean temperature increased by 0.86 °C on average at our sites during the last decade compared with previous 30-year period. Only one of the species studied, Abies alba, matched the expected predictions under the observed warming, with a maximum abundance of juveniles at higher altitudes than adults. Three species, Fagus sylvatica, Picea abies and Pinus sylvestris, showed an opposite pattern while for other three species, such as Quercus ilex, Acer pseudoplatanus and Q. petraea, we were no able to detect changes in distribution. These findings are in contrast with theoretical predictions and show that tree responses to climate change are complex and are obscured not only by other environmental factors but also by internal processes related to ontogeny and demography. PMID:23572443

Rabasa, Sonia G; Granda, Elena; Benavides, Raquel; Kunstler, Georges; Espelta, Josep M; Ogaya, Romá; Peñuelas, Josep; Scherer-Lorenzen, Michael; Gil, Wojciech; Grodzki, Wojciech; Ambrozy, Slawomir; Bergh, Johan; Hódar, José A; Zamora, Regino; Valladares, Fernando

2013-08-01

153

Activity restriction and the mechanistic basis for extinctions under climate warming.  

PubMed

Correlative analyses predict that anthropogenic climate warming will cause widespread extinction but the nature and generality of the underlying mechanisms is unclear. Warming-induced activity restriction has been proposed as a general explanatory mechanism for recent population extinctions in lizards, and has been used to forecast future extinction. Here, I test this hypothesis using globally applied biophysical calculations of the effects of warming and shade reduction on potential activity time and whole-life-cycle energy budgets. These 'thermodynamic niche' analyses show that activity restriction from climate warming is unlikely to provide a general explanation of recent extinctions, and that loss of shade is viable alternative explanation. Climate warming could cause population declines, even under increased activity potential, through joint impacts on fecundity and mortality rates. However, such responses depend strongly on behaviour, habitat (shade, food) and life history, all of which should be explicitly incorporated in mechanistic forecasts of extinction risk under climate change. PMID:24118740

R Kearney, Michael

2013-12-01

154

Projection of Summer Climate on Tokyo Metropolitan Area using Pseudo Global Warming Method  

NASA Astrophysics Data System (ADS)

Recent surface air temperature observations in most of urban areas show the remarkable increasing trend affected by the global warming and the heat island effects. There are many populous areas in Japan. In such areas, the effects of land-use change and urbanization on the local climate are not negligible (Fujibe, 2010). The heat stress for citizen there is concerned to swell moreover in the future. Therefore, spatially detailed climate projection is required for making adaptation and mitigation plans. This study focuses on the Tokyo metropolitan area (TMA) in summer and aims to estimate the local climate change over the TMA in 2070s using a regional climate model. The Regional Atmospheric Modeling System (RAMS) was used for downscaling. A single layer urban canopy model (Kusaka et al., 2001) is built into RAMS as a parameterization expressing the features of urban surface. We performed two experiments for estimating present and future climate. In the present climate simulation, the initial and boundary conditions for RAMS are provided from the JRA-25/JCDAS. On the other hand, the Pseudo Global Warming (PGW) method (Sato et al., 2007) is applied to estimate the future climate, instead of the conventional dynamical downscaling method. The PGW method is expected to reduce the model biases in the future projection estimated by Atmosphere-Ocean General Circulation Models (AOGCM). The boundary conditions used in the PGW method is given by the PGW data, which are obtained by adding the climate monthly difference between 1990s and 2070s estimated by AOGCMs to the 6-hourly reanalysis data. In addition, the uncertainty in the regional climate projection depending on the AOGCM projections is estimated from additional downscaling experiments using the different PGW data obtained from five AOGCMs. Acknowledgment: This work was supported by the Global Environment Research Fund (S-5-3) of the Ministry of the Environment, Japan. References: 1. Fujibe, F., Int. J. Climatol., doi:10.1002/joc.2142 (2010). 2. Kusaka, H., H. Kondo, Y. Kikegawa, and F. Kimura, Bound.-Layer Meteor., 101, 329-358 (2001). 3. Sato, T., F. Kimura, and A. Kitoh, J. Hydrology, 144-154 (2007).

Adachi, S. A.; Kimura, F.; Kusaka, H.; Hara, M.

2010-12-01

155

Soils Cool as Climate Warms in the Great Lakes Region: 19512000  

E-print Network

Soils Cool as Climate Warms in the Great Lakes Region: 1951­2000 S. A. Isard,* R. J. Schaetzl Lakes region. Key Words: climate, global change, Great Lakes region, lake-effect snow, soil temperatures. H istorical air temperature data series indicate that the climate of the Great Lakes region has been

Schaetzl, Randall

156

The toxicology of climate change: Environmental contaminants in a warming world  

Microsoft Academic Search

Climate change induced by anthropogenic warming of the earth's atmosphere is a daunting problem. This review examines one of the consequences of climate change that has only recently attracted attention: namely, the effects of climate change on the environmental distribution and toxicity of chemical pollutants. A review was undertaken of the scientific literature (original research articles, reviews, government and intergovernmental

Pamela D. Noyes; Matthew K. McElwee; Hilary D. Miller; Bryan W. Clark; Lindsey A. Van Tiem; Kia C. Walcott; Kyle N. Erwin; Edward D. Levin

2009-01-01

157

Precipitation Rates in a Stable Warm and Wet Climate on Early Mars  

NASA Astrophysics Data System (ADS)

The Noachian river valley networks on Mars are thought to have formed under warm and wet conditions. Two conditions need to be met. The surface temperatures must have been warm enough to allow liquid water at the surface, and enough precipitation must have fallen to the surface on a yearly basis to maintain at least a seasonal flow of water, or flash floods over a long period of time. Using a general circulation model, we find that a warm climate could have been sustained by the greenhouse effect created by the hydrological cycle on early Mars with a 500 mb CO2 atmosphere, and a reduced solar constant. The required conditions for such a climate are: an initial injection of atmospheric water or a low-albedo ice cap, relatively high clouds with particle sizes near 10 ?m that do not precipitate efficiently, and horizontally extensive clouds that trap outgoing infrared radiation. We also find that to have significant precipitation at latitudes where the river valleys are found requires local sources of water at the surface. In the case of a large initial injection of atmospheric water, such local sources of water can form as snow deposits when the planet is in high obliquity (?45°). Oceans can also act as a local source of water. We present simulation results with oceans that reach to -2550 m (Arabia shoreline in the northern hemisphere, Hellas basin, and Argyre basin in the southern hemisphere). Such oceans freeze quickly and form ice layers that are meters thick. However the amount of water sublimated from the ice is sufficient to create significant precipitation in non-polar latitudes at all obliquities. With oceans, the obliquity determines the latitude for highest precipitation. Then the obliquity cycle explains why the river valleys are found across such a wide range of latitudes.

Urata, Richard; Toon, O. B.

2012-10-01

158

Climate-induced changes in carbon and nitrogen cycling in the rapidly warming Antarctic coastal ocean   

E-print Network

The western Antarctic Peninsula (WAP) is a hotspot of climatic and oceanographic change, with a 6°C rise in winter atmospheric temperatures and >1°C warming of the surface ocean since the 1950s. These trends are having ...

Henley, Sian Frances

2013-07-01

159

A latitudinal gradient in tree growth response to climate warming in the Siberian taiga  

E-print Network

A latitudinal gradient in tree growth response to climate warming in the Siberian taiga A N D R E Siberian taiga species, Larix cajanderi, Picea obovata, and Pinus sylvestris, across a latitudinal gradient that increased productivity with warming is likely only in the northern reaches of the Siberian taiga

Wagner, Diane

160

Bring the Heat, but Hope for Rain: Adapting to Climate Warming for California  

E-print Network

increase water scarcity. Warm-only scarcity costs, however, are much less than costs for warm and temperature on California's hydrology and potential water management adaptations. Two climate scenarios water supply system is applied to explore water supply adaptation strategies for 2050 water demands

Lund, Jay R.

161

Simulated increase of hurricane intensities in a COâ-warmed climate  

Microsoft Academic Search

Hurricanes can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of these powerful storms could change in response to greenhouse gas-induced global warming. The impact of climate warming on hurricane intensities was investigated with a regional, high-resolution, hurricane prediction model. In a case study, 51 western Pacific storm cases under

T. R. Knutson; R. E. Tuleya; Y. Kurihara

1998-01-01

162

Climate change affects low trophic level marine consumers: warming decreases copepod size and abundance.  

PubMed

Concern about climate change has re-ignited interest in universal ecological responses to temperature variations: (1) biogeographical shifts, (2) phenology changes, and (3) size shifts. In this study we used copepods as model organisms to study size responses to temperature because of their central role in the pelagic food web and because of the ontogenetic length constancy between molts, which facilitates the definition of size of distinct developmental stages. In order to test the expected temperature-induced shifts towards smaller body size and lower abundances under warming conditions, a mesocosm experiment using plankton from the Baltic Sea at three temperature levels (ambient, ambient +4 °C, ambient -4 °C) was performed in summer 2010. Overall copepod and copepodit abundances, copepod size at all life stages, and adult copepod size in particular, showed significant temperature effects. As expected, zooplankton peak abundance was lower in warm than in ambient treatments. Copepod size-at-immature stage significantly increased in cold treatments, while adult size significantly decreased in warm treatments. PMID:25413864

Garzke, Jessica; Ismar, Stefanie M H; Sommer, Ulrich

2015-03-01

163

Local forcings affect lake zooplankton vulnerability and response to climate warming.  

PubMed

While considerable insights on the ecological consequences of climate change have been gained from studies conducted on remote lakes, little has been done on lakes under direct human exposure. Ecosystem vulnerability and responses to climate warming might yet largely depend on the ecological state and thus on local anthropogenic pressures. We tested this hypothesis through a paleolimnological approach on three temperate large lakes submitted to rather similar climate warming but varying intensities of analogous local forcings (changes in nutrient inputs and fisheries management practices). Changes in the structure of the cladoceran community were considered as revealing for alterations, over the time, of the pelagic food web. Trajectories of the cladoceran communities were compared among the three study lakes (Lakes Geneva, Bourget, and Annecy) over the last 70-150 years. Generalized additive models were used to develop a hierarchical understanding of the respective roles of local stressors and climate warming in structuring cladoceran communities. The cladoceran communities were not equally affected by climate warming between lakes. In Lake Annecy, which is the most nutrient-limited, the cladoceran community was essentially controlled by local stressors, with very limited impact of climate. In contrast, the more nutrient-loaded Lakes Geneva and Bourget were more sensitive to climate warming, although the magnitude of their responses and the pathways under which climate warming affected the communities varied between the two lakes. Finally, our results demonstrated that lake vulnerability and responses to climate warming are modulated by lake trophic status but can also be altered by fisheries management practices through changes in fish predation pressure. PMID:24597223

Alric, Benjamin; Jenny, Jean-Philippe; Berthon, Vincent; Arnaud, Fabien; Pignol, Cecile; Reyss, Jean-Louis; Sabatier, Pierre; Perga, Marie-Elodie

2013-12-01

164

Impacts of climate extremes on gross primary production under global warming  

NASA Astrophysics Data System (ADS)

The impacts of historical droughts and heat-waves on ecosystems are often considered indicative of future global warming impacts, under the assumption that water stress sets in above a fixed high temperature threshold. Historical and future (RCP8.5) Earth system model (ESM) climate projections were analyzed in this study to illustrate changes in the temperatures for onset of water stress under global warming. The ESMs examined here predict sharp declines in gross primary production (GPP) at warm temperature extremes in historical climates, similar to the observed correlations between GPP and temperature during historical heat-waves and droughts. However, soil moisture increases at the warm end of the temperature range, and the temperature at which soil moisture declines with temperature shifts to a higher temperature. The temperature for onset of water stress thus increases under global warming and is associated with a shift in the temperature for maximum GPP to warmer temperatures. Despite the shift in this local temperature optimum, the impacts of warm extremes on GPP are approximately invariant when extremes are defined relative to the optimal temperature within each climate period. The GPP sensitivity to these relative temperature extremes therefore remains similar between future and present climates, suggesting that the heat- and drought-induced GPP reductions seen recently can be expected to be similar in the future, and may be underestimates of future impacts given model projections of increased frequency and persistence of heat-waves and droughts. The local temperature optimum can be understood as the temperature at which the combination of water stress and light limitations is minimized, and this concept gives insights into how GPP responds to climate extremes in both historical and future climate periods. Both cold (temperature and light-limited) and warm (water-limited) relative temperature extremes become more persistent in future climate projections, and the time taken to return to locally optimal climates for GPP following climate extremes increases by more than 25% over many land regions.

Williams, I. N.; Torn, M. S.; Riley, W. J.; Wehner, M. F.

2014-09-01

165

Under the present phase of warming climate, the behaviour of Antarctica and the Southern Ocean are of paramount concern  

E-print Network

behaviour in the face of global warming. He said he was delighted to be able to "give something backIceSked Under the present phase of warming climate, the behaviour of Antarctica and the Southern and Technology to evaluate past warm periods. Named ANZICE (Antarctica-New Zealand Interglacial Climate Extremes

166

Effects of climate warming on polar bears: a review of the evidence.  

PubMed

Climate warming is causing unidirectional changes to annual patterns of sea ice distribution, structure, and freeze-up. We summarize evidence that documents how loss of sea ice, the primary habitat of polar bears (Ursus maritimus), negatively affects their long-term survival. To maintain viable subpopulations, polar bears depend on sea ice as a platform from which to hunt seals for long enough each year to accumulate sufficient energy (fat) to survive periods when seals are unavailable. Less time to access to prey, because of progressively earlier breakup in spring, when newly weaned ringed seal (Pusa hispida) young are available, results in longer periods of fasting, lower body condition, decreased access to denning areas, fewer and smaller cubs, lower survival of cubs as well as bears of other age classes and, finally, subpopulation decline toward eventual extirpation. The chronology of climate-driven changes will vary between subpopulations, with quantifiable negative effects being documented first in the more southerly subpopulations, such as those in Hudson Bay or the southern Beaufort Sea. As the bears' body condition declines, more seek alternate food resources so the frequency of conflicts between bears and humans increases. In the most northerly areas, thick multiyear ice, through which little light penetrates to stimulate biological growth on the underside, will be replaced by annual ice, which facilitates greater productivity and may create habitat more favorable to polar bears over continental shelf areas in the short term. If the climate continues to warm and eliminate sea ice as predicted, polar bears will largely disappear from the southern portions of their range by mid-century. They may persist in the northern Canadian Arctic Islands and northern Greenland for the foreseeable future, but their long-term viability, with a much reduced global population size in a remnant of their former range, is uncertain. PMID:24501049

Stirling, Ian; Derocher, Andrew E

2012-09-01

167

The Great Season Climatic Oscillation and the Global Warming  

Microsoft Academic Search

The present earth warming up is often explained by the atmosphere gas greenhouse effect. This explanation is in contradiction with the thermodynamics second law. The warming up by greenhouse effect is quite improbable. It is cloud reflection that gives to the earth s ground its 15 degres C mean temperature. Since the reflection of the radiation by gases is negligible,

Ahmed Boucenna

2008-01-01

168

Responses of alpine grassland on Qinghai-Tibetan plateau to climate warming and permafrost degradation: a modeling perspective  

NASA Astrophysics Data System (ADS)

Permafrost plays a critical role in soil hydrology. Thus, the degradation of permafrost under warming climate conditions may affect the alpine grassland ecosystem on the Qinghai-Tibetan Plateau. Previous space-for-time studies using plot and basin scales have reached contradictory conclusions. In this study, we applied a process-based ecosystem model (DOS-TEM) with a state-of-the-art permafrost hydrology scheme to examine this issue. Our results showed that 1) the DOS-TEM model could properly simulate the responses of soil thermal and hydrological dynamics and of ecosystem dynamics to climate warming and spatial differences in precipitation; 2) the simulated results were consistent with plot-scale studies showing that warming caused an increase in maximum unfrozen thickness, a reduction in vegetation and soil carbon pools as a whole, and decreases in soil water content, net primary production, and heterotrophic respiration; and 3) the simulated results were also consistent with basin-scale studies showing that the ecosystem responses to warming were different in regions with different combinations of water and energy constraints. Permafrost prevents water from draining into water reservoirs. However, the degradation of permafrost in response to warming is a long-term process that also enhances evapotranspiration. Thus, the degradation of the alpine grassland ecosystem on the Qinghai-Tibetan Plateau (releasing carbon) cannot be mainly attributed to the disappearing waterproofing function of permafrost.

Yi, Shuhua; Wang, Xiaoyun; Qin, Yu; Xiang, Bo; Ding, Yongjian

2014-07-01

169

Climate Warming, Marine Protected Areas and the Ocean-Scale Integrity of Coral Reef Ecosystems  

Microsoft Academic Search

Coral reefs have emerged as one of the ecosystems most vulnerable to climate variation and change. While the contribution of a warming climate to the loss of live coral cover has been well documented across large spatial and temporal scales, the associated effects on fish have not. Here, we respond to recent and repeated calls to assess the importance of

Nicholas A. J. Graham; Tim R. McClanahan; M. Aaron MacNeil; Shaun K. Wilson; Nicholas V. C. Polunin; Simon Jennings; Pascale Chabanet; Susan Clark; Mark D. Spalding; Yves Letourneur; Lionel Bigot; René Galzin; Marcus C. Öhman; Kajsa C. Garpe; Alasdair J. Edwards; Charles R. C. Sheppard

2008-01-01

170

Climate warming and the decline of amphibians and reptiles in Europe  

E-print Network

SPECIAL ISSUE Climate warming and the decline of amphibians and reptiles in Europe M. B. Arau´jo1 the relationship between current European distributions of amphibian and reptile species and observed climate ask, first, what proportion of amphibian and reptile species are projected to lose and gain suitable

Binford, Michael W.

171

Response of ocean ecosystems to climate warming J. L. Sarmiento,1  

E-print Network

the ocean biological response to climate warming between the beginning of the industrial revolution and 2050 production algorithms. We also show results for the period between the industrial revolution and 2050 by the American Geophysical Union. 0886-6236/04/2003GB002134$12.00 GB3003 6 Climate and Global Dynamics, National

Kleypas, Joanie

172

Climatic warming, glacier recession and runoff from Alpine basins after the Little Ice Age maximum  

Microsoft Academic Search

Records of discharge of rivers draining Alpine basins with between 0 and ?? 70% ice cover, in the upper Aare and Rhone catchments, Switzerland, for the period 1894-2006 have been examined together with climatic data for 1866-2006, with a view to assessing the effects on runoff from glacierized basins of climatic warming coupled with glacier recession following the Little Ice

David N. Collins

2008-01-01

173

Climate Warming, Marine Protected Areas and the Ocean-Scale Integrity of Coral Reef Ecosystems  

E-print Network

Climate Warming, Marine Protected Areas and the Ocean-Scale Integrity of Coral Reef Ecosystems as one of the ecosystems most vulnerable to climate variation and change. While the contribution of America, 3 National Research Council, NOAA Panama City Laboratory, Panama City Beach, Florida United

Paris-Sud XI, Université de

174

The Dynamic Response of the Greenland and Antarctic Ice Sheets to Multiple-Century Climatic Warming  

Microsoft Academic Search

New calculations were performed to investigate the combined response of the Greenland and Antarctic ice sheets to a range of climatic warming scenarios over the next millennium. Use was made of fully dynamic 3D thermomechanic ice sheet models, which were coupled to a two-dimensional climate model. The experiments were initialized with simulations over the last two glacial cycles to estimate

Philippe Huybrechts; Jan de Wolde

1999-01-01

175

Medical Providers as Global Warming and Climate Change Health Educators: A Health Literacy Approach  

ERIC Educational Resources Information Center

Climate change is a threat to wildlife and the environment, but it also one of the most pervasive threats to human health. The goal of this study was to examine the relationships among dimensions of health literacy, patient education about global warming and climate change (GWCC), and health behaviors. Results reveal that patients who have higher…

Villagran, Melinda; Weathers, Melinda; Keefe, Brian; Sparks, Lisa

2010-01-01

176

Geoengineering of climate warming TR 2:55-4:10 Bradfield 1102  

E-print Network

Geoengineering of climate warming TR 2:55-4:10 Bradfield 1102 Prerequisites: Math 1920 Geoengineering: the deliberate large-scale manipulation of the planetary environment to counteract anthropogenic strategies to geoengineer the climate (e.g., using balloon technology to emit reflecting sulfate aerosols

Mahowald, Natalie

177

ORIGINAL ARTICLE Advanced breeding dates in relation to recent climate warming  

E-print Network

Flycatcher Á Climate change Á Laying date Á Timing of breeding Introduction There is nowadays overwhelming evidence for both a recent increase in ambient temperatures at a global level and its effects on birdORIGINAL ARTICLE Advanced breeding dates in relation to recent climate warming in a Mediterranean

Potti, Jaime

178

Global Farm Animal Production and Global Warming: Impacting and Mitigating Climate Change  

Microsoft Academic Search

Background: The farm animal sector is the single largest anthropogenic user of land, contributing to many environmental problems, including global warming and climate change. Objectives: The aim of this study was to synthesize and expand upon existing data on the contribution of farm animal production to climate change. Methods: We analyzed the scientific literature on farm animal production and documented

Gowri Koneswaran; Danielle Nierenberg

2008-01-01

179

Persistent versus transient tree encroachment of temperate peat bogs: effects of climate warming and drought events.  

PubMed

Peatlands store approximately 30% of global soil carbon, most in moss-dominated bogs. Future climatic changes, such as changes in precipitation patterns and warming, are expected to affect peat bog vegetation composition and thereby its long-term carbon sequestration capacity. Theoretical work suggests that an episode of rapid environmental change is more likely to trigger transitions to alternative ecosystem states than a gradual, but equally large, change in conditions. We used a dynamic vegetation model to explore the impacts of drought events and increased temperature on vegetation composition of temperate peat bogs. We analyzed the consequences of six patterns of summer drought events combined with five temperature scenarios to test whether an open peat bog dominated by moss (Sphagnum) could shift to a tree-dominated state. Unexpectedly, neither a gradual decrease in the amount of summer precipitation nor the occurrence of a number of extremely dry summers in a row could shift the moss-dominated peat bog permanently into a tree-dominated peat bog. The increase in tree biomass during drought events was unable to trigger positive feedbacks that keep the ecosystem in a tree-dominated state after a return to previous 'normal' rainfall conditions. In contrast, temperature increases from 1 °C onward already shifted peat bogs into tree-dominated ecosystems. In our simulations, drought events facilitated tree establishment, but temperature determined how much tree biomass could develop. Our results suggest that under current climatic conditions, peat bog vegetation is rather resilient to drought events, but very sensitive to temperature increases, indicating that future warming is likely to trigger persistent vegetation shifts. PMID:23526779

Heijmans, Monique M P D; van der Knaap, Yasmijn A M; Holmgren, Milena; Limpens, Juul

2013-07-01

180

Climate warming and agricultural stressors interact to determine stream macroinvertebrate community dynamics.  

PubMed

Global climate change is likely to modify the ecological consequences of currently acting stressors, but potentially important interactions between climate warming and land-use related stressors remain largely unknown. Agriculture affects streams and rivers worldwide, including via nutrient enrichment and increased fine sediment input. We manipulated nutrients (simulating agricultural run-off) and deposited fine sediment (simulating agricultural erosion) (two levels each) and water temperature (eight levels, 0-6°C above ambient) simultaneously in 128 streamside mesocosms to determine the individual and combined effects of the three stressors on macroinvertebrate community dynamics (community composition and body size structure of benthic, drift and insect emergence assemblages). All three stressors had pervasive individual effects, but in combination often produced additive or antagonistic outcomes. Changes in benthic community composition showed a complex interplay among habitat quality (with or without sediment), resource availability (with or without nutrient enrichment) and the behavioural/physiological tendency to drift or emerge as temperature rose. The presence of sediment and raised temperature both resulted in a community of smaller organisms. Deposited fine sediment strongly increased the propensity to drift. Stressor effects were most prominent in the benthic assemblage, frequently reflected by opposite patterns in individuals quitting the benthos (in terms of their propensity to drift or emerge). Of particular importance is that community measures of stream health routinely used around the world (taxon richness, EPT richness and diversity) all showed complex three-way interactions, with either a consistently stronger temperature response or a reversal of its direction when one or both agricultural stressors were also in operation. The negative effects of added fine sediment, which were often stronger at raised temperatures, suggest that streams already impacted by high sediment loads may be further degraded under a warming climate. However, the degree to which this will occur may also depend on in-stream nutrient conditions. PMID:25581853

Piggott, Jeremy J; Townsend, Colin R; Matthaei, Christoph D

2015-05-01

181

Climate Conditioning for the Learning Environment.  

ERIC Educational Resources Information Center

Discusses heating, cooling, and ventilation for the classroom in relationship to students' learning abilities. It is designed to assist school boards, administrators, architects and engineers in understanding the beneficial effects of total climate control, and in evaluating the climate conditioning systems available for schools. Discussion…

Perkins and Will, Architects, Chicago, IL.

182

Seasonal Climate Extremes : Mechanism, Predictability and Responses to Global Warming  

Microsoft Academic Search

Climate extremes are rarely occurring natural phenomena in the climate system. They often pose one of the greatest environmental threats to human and natural systems. Statistical methods are commonly used to investigate characteristics of climate extremes. The fitted statistical properties are often interpolated or extrapolated to give an indication of the likelihood of a certain event within a given period

M. E. Shongwe

2010-01-01

183

Is the climate warming or cooling? David R. Easterling1  

E-print Network

.1029/2009GL037810. 1. Introduction [2] Anthropogenic climate change is one of the most contentious scientific, but this notion begs the question, what would happen to the current concerns about climate change if we do have-term climate change. On the other hand, segments of the general public do pay attention to these fluctuations

184

REGIONAL CLIMATE CHANGE SCENARIOS UNDER GLOBAL WARMING IN KAZAKHSTAN  

Microsoft Academic Search

The aim of this paper is to report on the development of regional climate change scenarios for Kazakhstan as the result of increasing of CO2 concentration in the global atmosphere. These scenarios are used in the assessment of climate change impacts on the agricultural, forest and water resources of Kazakhstan. Climate change scenarios for Kazakhstan to assess both long-term (2×

Olga V. Pilifosova; Irina B. Eserkepova; Svetlana A. Dolgih

1997-01-01

185

Climate-change impact potentials as an alternative to global warming potentials  

NASA Astrophysics Data System (ADS)

For policy applications, such as for the Kyoto Protocol, the climate-change contributions of different greenhouse gases are usually quantified through their global warming potentials. They are calculated based on the cumulative radiative forcing resulting from a pulse emission of a gas over a specified time period. However, these calculations are not explicitly linked to an assessment of ultimate climate-change impacts. A new metric, the climate-change impact potential (CCIP), is presented here that is based on explicitly defining the climate-change perturbations that lead to three different kinds of climate-change impacts. These kinds of impacts are: (1) those related directly to temperature increases; (2) those related to the rate of warming; and (3) those related to cumulative warming. From those definitions, a quantitative assessment of the importance of pulse emissions of each gas is developed, with each kind of impact assigned equal weight for an overall impact assessment. Total impacts are calculated under the RCP6 concentration pathway as a base case. The relevant climate-change impact potentials are then calculated as the marginal increase of those impacts over 100 years through the emission of an additional unit of each gas in 2010. These calculations are demonstrated for CO2, methane and nitrous oxide. Compared with global warming potentials, climate-change impact potentials would increase the importance of pulse emissions of long-lived nitrous oxide and reduce the importance of short-lived methane.

Kirschbaum, Miko U. F.

2014-03-01

186

Performance of RegCM2.5\\/NCAR-CSM Nested System for the Simulation of Climate Change in East Asia Caused by Global Warming  

Microsoft Academic Search

Regional climate in East Asia under 1CO2 and 2CO2 conditions, was simulated for continuous 10-year periods by the RegCM2.5 developed by NCAR, using the output of a CO2 transient run from NCAR-CSM as lateral and surface boundary conditions in order to evaluate the performance of the nested system for the use of climate change simulation caused by global warming for

Hisashi Kato; Keiichi Nishizawa; Hiromaru Hirakuchi; Shinji Kadokura; Naoko Oshima; Filippo Giorgi

2001-01-01

187

Expanding Peatlands in Alaska Caused by Accelerated Glacier Melting Under a Warming Climate  

NASA Astrophysics Data System (ADS)

Most mountain glaciers worldwide have been retreating over the last century due to global warming. This is particularly true around the Gulf of Alaska, where glacier recession has further accelerated since 1988. It is well known that glacier meltwater plays a critical role in the global sea level rise, but its effects on structure and functioning of peatland ecosystems remain poorly understood. We have observed in the field that many peatlands in the Susitna Basin, south-central Alaska, are expanding. As high moisture conditions are needed to promote peatland development and expansion, a regional change toward wetter conditions is likely responsible for the ongoing paludification of these peatlands. However, instrumental climatic data from this region show no increase in precipitation but an increase in temperature (and presumably evaporation) over the last decades. We hypothesize that climatically-induced glacier melting is modifying the local/regional climate, especially air humidity during the growing season, promoting the expansion of peatlands. To document recent peatland vertical growth and lateral expansion, we collected two long peat cores and twelve 30-cm-long monoliths in 2008 along a 110-m transect from an expanding peatland margin toward the peatland center. Ecohydrologic changes were reconstructed from testate amoebae and plant macrofossils assemblages. Preliminary results from both long cores revealed a change in the vegetation assemblages from a mesotrophic fen dominated by sedges and brown mosses to a Sphagnum-dominated peat bog at 11 cm, suggesting a very recent modification of the local hydrologic regime. A simultaneous increase in moisture was reconstructed from testate amoebae records. These unusual shifts in peatland development and hydrology (e.g., wet conditions triggering the fen-bog transition) imply a recent increase of atmospheric water to these peatlands. Our ongoing lead-210 dating and additional proxy analysis will help us resolve the timing and nature of recent peatland changes. These data, together with glacier history and climate records, will allow us to further test our hypothesis that the increase in glacier meltwater is causing peatland expansion By acting as water sinks, peatlands located in glacierized watersheds may mediate the contribution of meltwater to present and future sea-level rise. Increases in peat accumulation rates due to favorable hydroclimatic conditions are also expected to promote carbon sequestration by these ecosystems. In contrast to the expected desiccation of peatlands under a warmer climate, enhanced growth due to glaciers-climate feedbacks in high-latitude regions may thus promote peatland expansion, even just temporally.

Loisel, J.; Yu, Z.; Jones, M. C.

2009-05-01

188

Geographic Assessment Of Permafrost Bearing Capacity In Siberia Under Warming Climate  

NASA Astrophysics Data System (ADS)

More than 75% of engineering structures on permafrost in Russia are built according to the ”First Construction Principle”, which relies on the freezing strength (bearing capacity) of the frozen ground to support structures. For given surface and subsurface conditions, the bearing capacity depends strongly on the active layer thickness (ALT) and the temperature at the top of the permafrost (TTOP), both of which are strongly affected by the atmospheric climate. Increases in TTOP and ALT resulting from climatic warming can significantly reduce the bearing capacity of the frozen soil and the stability of engineered structures. We have developed a set of parameterizations to estimate the bearing capacity of frozen soils as function of TTOP and ALT, according to Russian Construction Rules and Regulations. The effect of climate on TTOP and ALT was estimated by an equilibrium permafrost model. Here, we present results from a geographic assessment of changes in the bearing capacity of permafrost soils attributable to observed climatic change in Siberia. Changes in bearing capacity for the last forty years were evaluated for several large settlements and industrial centers, representing different geographical conditions of the Russian Arctic. GIS-based landscape approach was used to apply model at the regional and continental scales to spatially assess changes in the permafrost temperature, the active-layer thickness and the bearing capacity in the North of West Siberia and for the entire Russian continuous permafrost zone. Substantial (up to 25%) loss in the bearing capacity of frozen soils is evident throughout the Russian permafrost zone. This in turn undermines the stability of infrastructure built on permafrost.

Shiklomanov, N. I.; Streletskyi, D.

2009-12-01

189

R E V I E W : E C O L O G Y Climate Warming and Disease Risks for  

E-print Network

, and humidity, creating synergisms that could affect biodiversity. Climate warming can increase pathogen- eral phytophagous insects (9). In Australia, the root-infecting fungus Phytophthora cinnamomi converted

190

Constant diurnal temperature regime alters the impact of simulated climate warming on a tropical pseudoscorpion.  

PubMed

Recent theory suggests that global warming may be catastrophic for tropical ectotherms. Although most studies addressing temperature effects in ectotherms utilize constant temperatures, Jensen's inequality and thermal stress considerations predict that this approach will underestimate warming effects on species experiencing daily temperature fluctuations in nature. Here, we tested this prediction in a neotropical pseudoscorpion. Nymphs were reared in control and high-temperature treatments under a constant daily temperature regime, and results compared to a companion fluctuating-temperature study. At constant temperature, pseudoscorpions outperformed their fluctuating-temperature counterparts. Individuals were larger, developed faster, and males produced more sperm, and females more embryos. The greatest impact of temperature regime involved short-term, adult exposure, with constant temperature mitigating high-temperature effects on reproductive traits. Our findings demonstrate the importance of realistic temperature regimes in climate warming studies, and suggest that exploitation of microhabitats that dampen temperature oscillations may be critical in avoiding extinction as tropical climates warm. PMID:24424082

Zeh, Jeanne A; Bonilla, Melvin M; Su, Eleanor J; Padua, Michael V; Anderson, Rachel V; Zeh, David W

2014-01-01

191

Constant diurnal temperature regime alters the impact of simulated climate warming on a tropical pseudoscorpion  

NASA Astrophysics Data System (ADS)

Recent theory suggests that global warming may be catastrophic for tropical ectotherms. Although most studies addressing temperature effects in ectotherms utilize constant temperatures, Jensen's inequality and thermal stress considerations predict that this approach will underestimate warming effects on species experiencing daily temperature fluctuations in nature. Here, we tested this prediction in a neotropical pseudoscorpion. Nymphs were reared in control and high-temperature treatments under a constant daily temperature regime, and results compared to a companion fluctuating-temperature study. At constant temperature, pseudoscorpions outperformed their fluctuating-temperature counterparts. Individuals were larger, developed faster, and males produced more sperm, and females more embryos. The greatest impact of temperature regime involved short-term, adult exposure, with constant temperature mitigating high-temperature effects on reproductive traits. Our findings demonstrate the importance of realistic temperature regimes in climate warming studies, and suggest that exploitation of microhabitats that dampen temperature oscillations may be critical in avoiding extinction as tropical climates warm.

Zeh, Jeanne A.; Bonilla, Melvin M.; Su, Eleanor J.; Padua, Michael V.; Anderson, Rachel V.; Zeh, David W.

2014-01-01

192

Constant diurnal temperature regime alters the impact of simulated climate warming on a tropical pseudoscorpion  

PubMed Central

Recent theory suggests that global warming may be catastrophic for tropical ectotherms. Although most studies addressing temperature effects in ectotherms utilize constant temperatures, Jensen's inequality and thermal stress considerations predict that this approach will underestimate warming effects on species experiencing daily temperature fluctuations in nature. Here, we tested this prediction in a neotropical pseudoscorpion. Nymphs were reared in control and high-temperature treatments under a constant daily temperature regime, and results compared to a companion fluctuating-temperature study. At constant temperature, pseudoscorpions outperformed their fluctuating-temperature counterparts. Individuals were larger, developed faster, and males produced more sperm, and females more embryos. The greatest impact of temperature regime involved short-term, adult exposure, with constant temperature mitigating high-temperature effects on reproductive traits. Our findings demonstrate the importance of realistic temperature regimes in climate warming studies, and suggest that exploitation of microhabitats that dampen temperature oscillations may be critical in avoiding extinction as tropical climates warm. PMID:24424082

Zeh, Jeanne A.; Bonilla, Melvin M.; Su, Eleanor J.; Padua, Michael V.; Anderson, Rachel V.; Zeh, David W.

2014-01-01

193

Are treelines advancing? A global meta-analysis of treeline response to climate warming.  

PubMed

Treelines are temperature sensitive transition zones that are expected to respond to climate warming by advancing beyond their current position. Response to climate warming over the last century, however, has been mixed, with some treelines showing evidence of recruitment at higher altitudes and/or latitudes (advance) whereas others reveal no marked change in the upper limit of tree establishment. To explore this variation, we analysed a global dataset of 166 sites for which treeline dynamics had been recorded since 1900 AD. Advance was recorded at 52% of sites with only 1% reporting treeline recession. Treelines that experienced strong winter warming were more likely to have advanced, and treelines with a diffuse form were more likely to have advanced than those with an abrupt or krummholz form. Diffuse treelines may be more responsive to warming because they are more strongly growth limited, whereas other treeline forms may be subject to additional constraints. PMID:19682007

Harsch, Melanie A; Hulme, Philip E; McGlone, Matt S; Duncan, Richard P

2009-10-01

194

Evidence for 20th century climate warming and wetland drying in the North American Prairie Pothole Region.  

PubMed

The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946-1975; 1976-2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland-dependent species. PMID:24223283

Werner, Brett A; Johnson, W Carter; Guntenspergen, Glenn R

2013-09-01

195

Evidence for 20th century climate warming and wetland drying in the North American Prairie Pothole Region  

PubMed Central

The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate change may have been sufficient to have a significant impact on wetland cover cycling. Modeled wetlands in the PPR's western Canadian prairies show the most dramatic effects: a recent trend toward shorter hydroperiods and less dynamic vegetation cycles, which already may have reduced the productivity of hundreds of wetland-dependent species. PMID:24223283

Werner, Brett A; Johnson, W Carter; Guntenspergen, Glenn R

2013-01-01

196

Climatic changes and associated impacts in the Mediterranean resulting from a 2 °C global warming  

NASA Astrophysics Data System (ADS)

Climatic changes over the Mediterranean basin in 2031-2060, when a 2 °C global warming is most likely to occur, are investigated with the HadCM3 global circulation model and their impacts on human activities and natural ecosystem are assessed. Precipitation and surface temperature changes are examined through mean and extreme values analysis, under the A2 and B2 emission scenarios. Confidence in results is obtained via bootstrapping. Over the land areas, the warming is larger than the global average. The rate of warming is found to be around 2 °C in spring and winter, while it reaches 4 °C in summer. An additional month of summer days is expected, along with 2-4 weeks of tropical nights. Increase in heatwave days and decrease in frost nights are expected to be a month inland. In the northern part of the basin the widespread drop in summer rainfall is partially compensated by a winter precipitation increase. One to 3 weeks of additional dry days lead to a dry season lengthened by a week and shifted toward spring in the south of France and inland Algeria, and autumn elsewhere. In central Mediterranean droughts are extended by a month, starting a week earlier and ending 3 weeks later. The impacts of these climatic changes on human activities such as agriculture, energy, tourism and natural ecosystems (forest fires) are also assessed. Regarding agriculture, crops whose growing cycle occurs mostly in autumn and winter show no changes or even an increase in yield. In contrast, summer crops show a remarkable decrease of yield. This different pattern is attributed to a lengthier drought period during summer and to an increased rainfall in winter and autumn. Regarding forest fire risk, an additional month of risk is expected over a great part of the basin. Energy demand levels are expected to fall significantly during a warmer winter period inland, whereas they seem to substantially increase nearly everywhere during summer. Extremely high summer temperatures in the Mediterranean, coupled with improved climate conditions in northern Europe, may lead to a gradual decrease in summer tourism in the Mediterranean, but an increase in spring and autumn.

Giannakopoulos, C.; Le Sager, P.; Bindi, M.; Moriondo, M.; Kostopoulou, E.; Goodess, C. M.

2009-08-01

197

The Early Climate History of Mars: "Warm and Wet" or "Cold and Icy"?  

NASA Astrophysics Data System (ADS)

The Amazonian climate (last ~66% of history) was much like today, a cold and dry climate regime, characterized by the latitudinal migration of surface ice in response to variations in spin-axis/orbital parameters. But what characterized the Noachian climate (first ~20% of history)? Some data support a "warm and wet" early Mars, but this evidence has been challenged. New models of early Mars climate (Forget, Wordsworth et al.) find that for atmospheric pressures greater than a few hundred millibars, surface temperatures vary with altitude due to atmosphere-surface thermal coupling: an adiabatic cooling effect (ACE) results in deposition of snow and ice at high altitudes, in contrast to Amazonian conditions. Without other warming mechanisms, no combination of parameters lead to mean annual surface temperatures (MAT) consistent with widespread liquid water anywhere on the planet. The ACE causes southern highland region temperatures to fall significantly below the global average leading to a "Noachian Icy Highlands" scenario: Water is transported to the highlands from low-lying regions due to the ACE and snows out to form an extended H2O ice cap at the southern pole, and altitude-dependent snow and ice deposits down to lower southern latitudes. Could the predictions of this "Noachian Icy Highlands" model be consistent with the many lines of evidence traditionally cited for a "warm, wet" early Mars? Perturbing this predominant Noachian environment with punctuated impacts and volcanism/greenhouse gases would lead to raising of global surface temperatures toward the melting point of water, with the following consequences: 1) ice above the surface ice stability line undergoes rapid altitude/latitude dependent warming during each Mars summer; 2) meltwater runoff from the continuous ice sheet drains and flows downslope to the edge of the ice sheet, where meltwater channels encounter cratered terrain, forming closed-basin and open-basin lakes; 3) seasonal top-down heating and melting of the top tens of meters of continuous ice produce a volume of water well in excess of the total volume interpreted to have occupied open-basin/closed basin lakes; 4) this meltwater initially erodes into the dry regolith down to the top of the ice table, producing a perched aquifer and more efficient erosion than infiltration alone; 5) at the end of the annual melting period, temperatures return to below 0°C, meltwater freezes and sublimes, returning to high altitudes as snowfall to replenish the snow and ice deposit; 6) this Noachian icy highlands, ACE-dominated water cycle persists until MAT drops to <0°C. The icy Noachian highlands/punctuated volcanism scenario appears to be able to account for the: 1) source and volume of water required for valley networks; 2) presence of closed/open-basin lakes; 4) evidence for recurring phases of activity over millions of years; 5) small amounts of net erosion; 6) relatively poor stream integration and lower order; 7) presence of a surface hydrological cycle that can replenish the source area and cause recurring activity with a small total budget of water; and 8) presence of melting and runoff in a Late Noachian climate compatible with other constraints (e.g., faint young Sun, low atmospheric pressure).

Head, James

2013-04-01

198

Teaching about Climate Change: Cool Schools Tackle Global Warming.  

ERIC Educational Resources Information Center

Within the last couple of decades, the concentration of greenhouse gases in the atmosphere has increased significantly due to human activities. Today climate change is an important issue for humankind. This book provides a starting point for educators to teach about climate change, although there are obstacles caused by the industrialized…

Grant, Tim, Ed.; Littlejohn, Gail, Ed.

199

Committed warming and its implications for climate change  

Microsoft Academic Search

Time lags between changes in radiative forcing and the resulting simulated climate responses are investigated in a set of transient climate change experiments. Both surface air temperature (SAT) and soil moisture responses are examined. Results suggest that if the radiative forcing is held fixed at today's levels, the global mean SAT will rise an additional 1.0 K before equilibrating. This

Richard T. Wetherald; Ronald J. Stouffer; Keith W. Dixon

2001-01-01

200

Climatic Warming Increases Winter Wheat Yield but Reduces Grain Nitrogen Concentration in East China  

PubMed Central

Climatic warming is often predicted to reduce wheat yield and grain quality in China. However, direct evidence is still lacking. We conducted a three-year experiment with a Free Air Temperature Increase (FATI) facility to examine the responses of winter wheat growth and plant N accumulation to a moderate temperature increase of 1.5°C predicted to prevail by 2050 in East China. Three warming treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming) were applied for an entire growth period. Consistent warming effects on wheat plant were recorded across the experimental years. An increase of ca. 1.5°C in daily, daytime and nighttime mean temperatures shortened the length of pre-anthesis period averagely by 12.7, 8.3 and 10.7 d (P<0.05), respectively, but had no significant impact on the length of the post-anthesis period. Warming did not significantly alter the aboveground biomass production, but the grain yield was 16.3, 18.1 and 19.6% (P<0.05) higher in the AW, DW and NW plots than the non-warmed plot, respectively. Warming also significantly increased plant N uptake and total biomass N accumulation. However, warming significantly reduced grain N concentrations while increased N concentrations in the leaves and stems. Together, our results demonstrate differential impacts of warming on the depositions of grain starch and protein, highlighting the needs to further understand the mechanisms that underlie warming impacts on plant C and N metabolism in wheat. PMID:24736557

Deng, Aixing; Song, Zhenwei; Zhang, Baoming; Zhang, Weijian

2014-01-01

201

Climatic warming increases winter wheat yield but reduces grain nitrogen concentration in east China.  

PubMed

Climatic warming is often predicted to reduce wheat yield and grain quality in China. However, direct evidence is still lacking. We conducted a three-year experiment with a Free Air Temperature Increase (FATI) facility to examine the responses of winter wheat growth and plant N accumulation to a moderate temperature increase of 1.5°C predicted to prevail by 2050 in East China. Three warming treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming) were applied for an entire growth period. Consistent warming effects on wheat plant were recorded across the experimental years. An increase of ca. 1.5°C in daily, daytime and nighttime mean temperatures shortened the length of pre-anthesis period averagely by 12.7, 8.3 and 10.7 d (P<0.05), respectively, but had no significant impact on the length of the post-anthesis period. Warming did not significantly alter the aboveground biomass production, but the grain yield was 16.3, 18.1 and 19.6% (P<0.05) higher in the AW, DW and NW plots than the non-warmed plot, respectively. Warming also significantly increased plant N uptake and total biomass N accumulation. However, warming significantly reduced grain N concentrations while increased N concentrations in the leaves and stems. Together, our results demonstrate differential impacts of warming on the depositions of grain starch and protein, highlighting the needs to further understand the mechanisms that underlie warming impacts on plant C and N metabolism in wheat. PMID:24736557

Tian, Yunlu; Zheng, Chengyan; Chen, Jin; Chen, Changqing; Deng, Aixing; Song, Zhenwei; Zhang, Baoming; Zhang, Weijian

2014-01-01

202

Warm Rain Processes Over the Tropical Oceans and Implications on Climate Change  

NASA Technical Reports Server (NTRS)

In this talk, we will first show results from TRMM regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to a larger portion of the increase. The abundant rainout of warm precipitation at middle to low levels causes a reduction of high cloud cover due to the depletion of water available for ice-phase rain production. As a result, more isolated, but more intense penetrative convection develops. Results also show that increased autoconversion reduces the convective adjustment time scale tends, implying a faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbance on daily to weekly time scales. The causes of the sensitivity of the dynamical regimes to the microphysics parameterization in the GCM will be discussed.

Lau, William K. M.; Wu, H. T.

2004-01-01

203

Climate warming mediates negative impacts of rapid pond drying for three amphibian species.  

PubMed

Anthropogenic climate change will present both opportunities and challenges for pool-breeding amphibians. Increased water temperature and accelerated drying may directly affect larval growth, development, and survival, yet the combined effects of these processes on larvae with future climate change remain poorly understood. Increased surface temperatures are projected to warm water and decrease water inputs, leading to earlier and faster wetland drying. So it is often assumed that larvae will experience negative synergistic impacts with combined warming and drying. However, an alternative hypothesis is that warming-induced increases in metabolic rate and aquatic resource availability might compensate for faster drying rates, generating antagonistic larval responses. We conducted a mesocosm experiment to test the individual and interactive effects of pool permanency (permanent vs. temporary) and water temperature (ambient vs. (+) -3 degrees C) on three anurans with fast-to-slow larval development rates (Great Basin spadefoot [Spea intermontana], Pacific chorus frog [Pseudacris regilla], and northern red-legged frog [Rana aurora]). We found that although tadpoles in warmed pools reached metamorphosis 15-17 days earlier, they did so with little cost (< 2 mm) to size, likely due to greater periphyton growth in warmed pools easing drying-induced resource competition. Warming and drying combined to act antagonistically on early growth (P = 0.06) and survival (P = 0.06), meaning the combined impact was less than the sum of the individual impacts. Warming and drying acted additively on time to and size at metamorphosis. These nonsynergistic impacts may result from cotolerance of larvae to warming and drying, as well as warming helping to offset negative impacts of drying. Our results indicate that combined pool warming and drying may not always be harmful for larval amphibians. However, they also demonstrate that antagonistic responses are difficult to predict, which poses a challenge to proactive conservation and management. Our study highlights the importance of considering the nature of multiple stressor interactions as amphibians are exposed to an increasing number of anthropogenic threats. PMID:24933805

O'Regan, Sacha M; Palen, Wendy J; Anderson, Sean C

2014-04-01

204

Effects of Global Warming on Predatory Bugs Supported by Data Across Geographic and Seasonal Climatic Gradients.  

PubMed

Global warming may affect species abundance and distribution, as well as temperature-dependent morphometric traits. In this study, we first used historical data to document changes in Orius (Heteroptera: Anthocoridae) species assemblage and individual morphometric traits over the past seven decades in Israel. We then tested whether these changes could have been temperature driven by searching for similar patterns across seasonal and geographic climatic gradients in a present survey. The historical records indicated a shift in the relative abundance of dominant Orius species; the relative abundance of O. albidipennis, a desert-adapted species, increased while that of O. laevigatus decreased in recent decades by 6 and 10-15 folds, respectively. These shifts coincided with an overall increase of up to 2.1°C in mean daily temperatures over the last 25 years in Israel. Similar trends were found in contemporary data across two other climatic gradients, seasonal and geographic; O. albidipennis dominated Orius assemblages under warm conditions. Finally, specimens collected in the present survey were significantly smaller than those from the 1980's, corresponding to significantly smaller individuals collected now during warmer than colder seasons. Taken together, results provide strong support to the hypothesis that temperature is the most likely driver of the observed shifts in species composition and body sizes because (1) historical changes in both species assemblage and body size were associated with rising temperatures in the study region over the last few decades; and (2) similar changes were observed as a result of contemporary drivers that are associated with temperature. PMID:23805249

Schuldiner-Harpaz, Tarryn; Coll, Moshe

2013-01-01

205

Reconstruction of spatial patterns of climatic anomalies during the medieval warm period (AD 900-1300)  

SciTech Connect

The workshop will focus on climatic variations during the Medieval Warm Period or Little Climatic Optimum. The nominal time interval assigned to this period is AD 900--1300, but climate information available during the century or two preceding and following this episode is welcome. The aims of the workshop will be to: examine the available evidence for the existence of this episode; assess the spatial and temporal synchronicity of the climatic signals; discuss possible forcing mechanisms; and identify areas and paleoenvironmental records where additional research efforts are needed to improve our knowledge of this period. This document consists of abstracts of eighteen papers presented at the meeting.

Diaz, H.F. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Research Labs.; Hughes, M.K. [Arizona Univ., Tucson, AZ (United States). Lab. of Tree-Ring Research

1992-12-31

206

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

PubMed

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, emphasizing local-scale effects, and including a priori knowledge of relevant natural history for the taxa and regions under study. PMID:24934878

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

207

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

PubMed Central

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, emphasizing local-scale effects, and including a priori knowledge of relevant natural history for the taxa and regions under study. PMID:24934878

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

208

The integrated hydrologic and societal impacts of a warming climate in interior Alaska  

NASA Astrophysics Data System (ADS)

In this dissertation, interdisciplinary research methods were used to examine how changes in hydrology associated with climate affect Alaskans. Partnerships were established with residents of Fairbanks and Tanana to develop scientific investigations relevant to rural Alaskans. In chapter 2, local knowledge was incorporated into scientific models to identify a social-ecological threshold used to model potential driftwood harvest from the Yukon River. Anecdotal evidence and subsistence calendar records were combined with scientific data to model the harvest rates of driftwood. Modeling results estimate that between 1980 and 2010 hydrologic factors alone were responsible for a 29% decrease in the annual wood harvest, which approximately balanced a 23% reduction in wood demand due to a decline in number of households. The community's installation of wood-fired boilers in 2007 created a threshold increase (76%) in wood demand that is not met by driftwood harvest. Modeling of climatic scenarios illustrates that increased hydrologic variability decreases driftwood harvest and increases the financial or temporal costs for subsistence users. In chapter 3, increased groundwater flow related to permafrost degradation was hypothesized to be affect river ice thickness in sloughs of the Tanana River. A physically-based, numerical model was developed to examine the importance of permafrost degradation in explaining unfrozen river conditions in the winter. Results indicated that ice melt is amplified by increasing groundwater upwelling rates, groundwater temperatures, and snowfall. Modeling results also suggest that permafrost degradation could be a valid explanation of the phenomenon, but does not address the potential drivers (e.g. warming climate, forest fire, etc.) of the permafrost warming. In chapter 4, remote sensing techniques were hypothesized to be useful for mapping dangerous ice conditions on the Tanana River in interior Alaska. Unsupervised classification of high-resolution satellite imagery was used to identify and map open water and degraded ice conditions on the Tanana River. Ninety-five percent of the total river channel surface was classified as "safe" for river travel, while 4% of the channel was mapped as having degraded ice and 0.6% of the channel was classified as open water (overall accuracy of 73%). This research demonstrates that the classification of high-resolution satellite images can be useful for mapping hazardous ice for recreational, transportation, or industrial applications in northern climates. These results are applicable to communities throughout the North. For people that rely upon subsistence activities, increased variability in climate cycles can have substantial financial, cultural, recreational, or even mortal consequences. This research demonstrates how collaborations between scientists and local stakeholders can create tools that help to assess the impacts of increased environmental variability (such as flooding) or to detect or predict unsafe conditions (such as thin or unpredictable ice cover). Based upon this research, I conclude that regional-scale adaptations and technological advances (such as modeling and remote sensing tools) may help to alleviate the effects of environmental variability associated by climate.

Jones, Charles E., Jr.

209

The impact of warming climate on late summer snow cover in northwestern Finland  

NASA Astrophysics Data System (ADS)

Snowbeds and snow patches are characteristic features of arctic and alpine regions and are classified as endangered habitats due to the warming climate. We studied interannual variation of late summer snow cover and the factors affecting it in sub-arctic Enontekiö Lapland, northwestern Finland in years 2000, 2004, 2006, and 2009. Snow cover at 30 m resolution was derived from Landsat TM and ETM+ images obtained between 27 July and 4 August using a normalized difference snow index (NDSI). A generalized linear model (GLM) was constructed for the number (0 - 4) of snow occurrence years in 1-km grid squares. Explanatory variables in the model were elevation, terrain ruggedness, insolation and aspect. Variation in climatic conditions in the study region was examined using temperature and precipitation data from 1995 to 2009 (Finnish Meteorological Institute) and climate scenarios derived from the ENSEMBLES and PRUDENCE simulations extending to the period of 2070-2099. Late summer snow covered 23.0 km2 in 2000, 2.7 km2 in 2004, 1.5 km2 in 2006, and 5.0 km2 in 2009 of the 3176.5 km2 study area (mean altitude 727 m, maximum altitude 1310 m). The decline of snow cover was most prominent below 900 meters and on southern and western slopes. In year 2000, approximately a half of the snow cover was found above 900 meters (where 7% of the total study area is located) compared to circa 75% in 2004 and 2006, and 62% in 2009. Analyses at the 1-km resolution showed that in 19 % of the study squares there was late summer snow at least in one of the four years. Elevation and terrain ruggedness were the strongest explanatory variables for the number of snow occurrence year in a univariate GLM model. The GLM model including all variables explained 73% of the variation in the number of snow occurrence years. The interannual variation in late summer snow cover reflects the climatic variation in the study region. The mean annual temperature increased on average by 0.16°C per year during 1995-2009. Warming was most noticeable in November-December (0.37°C/year) and April- May (0.33°C/year). The number of frost days and the proportion of the snow of the total precipitation amount generally decreased during the study period. A higher number of frost days and a snowfall peak in 2008 probably explain the observed slight increase in the summer snow cover in 2009. ENSEMBLES models predict the greatest warming to take place in winter, from late autumn to early spring (ca 5.5°C by 2070-2099). Snowfall is predicted to increase 7-26% in November-March and to decrease notably in April-October. Further, PRUDENCE models predict a significant decrease in the number of frost days from average of 240 in 1961-1990 to 185 in 2071-2100. These results suggest that future climatic conditions in the study area will not support the summer occurrence of snowbeds and snow patches, which leads to threat to the alpine species and communities associated with snow and moist soils.

Kivinen, S.; Kaarlejärvi, E.; Jylhä, K.; Räisänen, J.

2012-04-01

210

Climate sensitivity of tropical and subtropical marine low cloud amount to ENSO and global warming due to doubled CO2  

E-print Network

Climate sensitivity of tropical and subtropical marine low cloud amount to ENSO and global warming of tropical and subtropical marine low cloud amount to ENSO and global warming due to doubled CO2, J. Geophys-level clouds can markedly offset or amplify the global warming due to increasing greenh

Bretherton, Chris

211

WHAT TO DO ABOUT CLIMATE CHANGE? Slowing the rate of carbon burning won't stop global warming  

E-print Network

WHAT TO DO ABOUT CLIMATE CHANGE? #12;Slowing the rate of carbon burning won't stop global warming: most CO2 stays in the air over a century, though individual molecules come and go. Global warming. But we need to research it -- starting now. If global warming gets bad, public opinion may suddently flip

Baez, John

212

Predicting organismal vulnerability to climate warming: roles of behaviour,  

E-print Network

temperatures) that are often available for some groups. Several proxies for ectotherms are promising that ectotherms sharing vulnerability traits seem concentrated in lowland tropical forests. Their vulnerability, the prospects for tropical forest ectotherms appear grim. Keywords: climate change; ectotherms; endotherms

Huey, Raymond B.

213

Marshy pools on permafrost mitigate landscape-scale climate warming  

NASA Astrophysics Data System (ADS)

Starting 5000 years ago, small marshy lakes dotting northern Siberia became significant carbon sinks, cooling the climate on a landscape scale. Researchers from the University of Alaska Fairbanks (UAF) published their findings in Nature online on 16 July.

Wendel, JoAnna

2014-07-01

214

Pacific Shallow Meridional Overturning Circulation in a Warming Climate  

E-print Network

By analyzing a set of the Coupled Model Intercomparison Project phase 3 (CMIP3) climate model projections of the twenty-first century, it is found that the shallow meridional overturning of the Pacific subtropical cells ...

Wang, Daiwei

215

Communicating Climate Uncertainties: Challenges and Opportunities Related to Spatial Scales, Extreme Events, and the Warming 'Hiatus'  

NASA Astrophysics Data System (ADS)

Many media, academic, government, and advocacy organizations have achieved sophistication in developing effective messages based on scientific information, and can quickly translate salient aspects of emerging climate research and evolving observations. However, there are several ways in which valid messages can be misconstrued by decision makers, leading them to inaccurate conclusions about the risks associated with climate impacts. Three cases will be discussed: 1) Issues of spatial scale in interpreting climate observations: Local climate observations may contradict summary statements about the effects of climate change on larger regional or global spatial scales. Effectively addressing these differences often requires communicators to understand local and regional climate drivers, and the distinction between a 'signal' associated with climate change and local climate 'noise.' Hydrological statistics in Missouri and California are shown to illustrate this case. 2) Issues of complexity related to extreme events: Climate change is typically invoked following a wide range of damaging meteorological events (e.g., heat waves, landfalling hurricanes, tornadoes), regardless of the strength of the relationship between anthropogenic climate change and the frequency or severity of that type of event. Examples are drawn from media coverage of several recent events, contrasting useful and potentially confusing word choices and frames. 3) Issues revolving around climate sensitivity: The so-called 'pause' or 'hiatus' in global warming has reverberated strongly through political and business discussions of climate change. Addressing the recent slowdown in warming yields an important opportunity to raise climate literacy in these communities. Attempts to use recent observations as a wedge between climate 'believers' and 'deniers' is likely to be counterproductive. Examples are drawn from Congressional testimony and media stories. All three cases illustrate ways that decision makers can arrive at invalid conclusions from a seemingly valid scientific messages. Honest discussion of uncertainties, and recognition of the spatial and time scales associated with decision making, can work to combat this potential confusion.

Casola, J. H.; Huber, D.

2013-12-01

216

Is Global Warming Injecting Randomness into the Climate System?  

Microsoft Academic Search

Data analyses and model simulations have indicated that as the planet is warming, the chance for extreme events increases. Karl et al. [1995] examined precipitation records over the 20th century and showed that the high-frequency (up to interannual) variability has increased. Subsequently, Tsonis [1996] showed that the low-frequency variability has also increased. These variability trends indicate that the frequency of

A. A. Tsonis

2004-01-01

217

Evaluation of Laboratory Conditioning Protocols for Warm-Mix Asphalt  

E-print Network

Warm-Mix Asphalt (WMA) refers to the asphalt concrete paving material produced and placed at temperatures approximately 50°F lower than those used for Hot-Mix Asphalt (HMA). Economic, environmental and engineering benefits have boosted the use...

Yin, Fan 1990-

2012-10-26

218

Climate Kids: It's Cold! Is Global Warming Over?  

NSDL National Science Digital Library

The movement of Arctic air, known as the Arctic oscillation, can and will cause periodic extreme winter weather outside the Arctic region - the harsh winter experienced in many parts of the U.S. in 2010 is a recent example. This article explains the connection between the two events. This article is part of the Climate Kids website, a NASA education resource featuring articles, videos, images and games focused on the science of climate change.

2013-11-07

219

Dividing climate change: global warming in the Indian mass media  

Microsoft Academic Search

Much research has now been conducted into the representation of climate change in the media. Specifically, the communication\\u000a of climate change from scientists and policy-makers to the public via the mass media has been a subject of major interest\\u000a because of its implications for creating national variation in public understanding of a global environmental issue. However,\\u000a to date, no study

Simon Billett

2010-01-01

220

Links between plant species’ spatial and temporal responses to a warming climate  

PubMed Central

To generate realistic projections of species’ responses to climate change, we need to understand the factors that limit their ability to respond. Although climatic niche conservatism, the maintenance of a species’s climatic niche over time, is a critical assumption in niche-based species distribution models, little is known about how universal it is and how it operates. In particular, few studies have tested the role of climatic niche conservatism via phenological changes in explaining the reported wide variance in the extent of range shifts among species. Using historical records of the phenology and spatial distribution of British plants under a warming climate, we revealed that: (i) perennial species, as well as those with weaker or lagged phenological responses to temperature, experienced a greater increase in temperature during flowering (i.e. failed to maintain climatic niche via phenological changes); (ii) species that failed to maintain climatic niche via phenological changes showed greater northward range shifts; and (iii) there was a complementary relationship between the levels of climatic niche conservatism via phenological changes and range shifts. These results indicate that even species with high climatic niche conservatism might not show range shifts as instead they track warming temperatures during flowering by advancing their phenology. PMID:24478304

Amano, Tatsuya; Freckleton, Robert P.; Queenborough, Simon A.; Doxford, Simon W.; Smithers, Richard J.; Sparks, Tim H.; Sutherland, William J.

2014-01-01

221

Projection of global warming onto regional precipitation over Mongolia using a regional climate model  

Microsoft Academic Search

Climate change due to global warming is of concern to the public and may cause significant changes in the hydrological regimes in arid\\/semi-arid areas including Mongolia, which locates at a boundary between arid and humid regions. However, general circulation models (GCMs) are not sufficient to evaluate climate change on a regional-scale. In this study, two kinds of dynamical downscaling (DDS),

Tomonori Sato; Fujio Kimura; Akio Kitoh

2007-01-01

222

Potential impacts of a warming climate on water availability in snow-dominated regions  

Microsoft Academic Search

All currently available climate models predict a near-surface warming trend under the influence of rising levels of greenhouse gases in the atmosphere. In addition to the direct effects on climate—for example, on the frequency of heatwaves—this increase in surface temperatures has important consequences for the hydrological cycle, particularly in regions where water supply is currently dominated by melting snow or

J. C. Adam; T. P. Barnett; D. P. Lettenmaier

2005-01-01

223

Vulnerability of Lake Tahoe (CA-NV) mixing patterns in response to global warming and climate change  

Microsoft Academic Search

Meteorological-driven processes exert large and diverse impacts on lakes internal heating, cooling and mixing. Thus, lakes' mixing pattern and ecosystem will likely be affected with continued global warming and climate change. The impact of climate change on Lake Tahoe (California-Nevada) was investigated here as a case study of climate change effects on the physical processes occurring within the lake. Climate

G. B. Sahoo; G. Schladow; J. E. Reuter

2008-01-01

224

Freezing of Martian streams under climatic conditions  

NASA Technical Reports Server (NTRS)

The valley networks of Mars are widely believed to have formed at a time when climatic conditions on the planet were significantly different from those that currently prevail. This view arises from the following observations: (1) the valleys form integrated branching networks which suggests fluid drainage, and water is the most plausible fluid, (2) the present atmosphere contains only minute amounts of water, (3) the networks appear to be more akin to terrestrial valleys that are eroded by streams of modest discharges than features that form by catastrophic floods, and (4) small streams of water will rapidly freeze under present climatic conditions. Climatic conditions at the time of formation of the valleys are studied based on the assumption that they were cut by running water.

Carr, M. H.

1984-01-01

225

Ecosystem resilience despite large-scale altered hydro climatic conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological paradigm for many regions. Large-scale, warm droughts have recently impacted North America, Africa, Europe, Amazonia, and Australia result...

226

Large Impacts of Climatic Warming on Growth of Boreal Forests since 1960  

PubMed Central

Boreal forests are sensitive to climatic warming, because low temperatures hold back ecosystem processes, such as the mobilization of nitrogen in soils. A greening of the boreal landscape has been observed using remote sensing, and the seasonal amplitude of CO2 in the northern hemisphere has increased, indicating warming effects on ecosystem productivity. However, field observations on responses of ecosystem productivity have been lacking on a large sub-biome scale. Here we report a significant increase in the annual growth of boreal forests in Finland in response to climatic warming, especially since 1990. This finding is obtained by linking meteorological records and forest inventory data on an area between 60° and 70° northern latitude. An additional increase in growth has occurred in response to changes in other drivers, such as forest management, nitrogen deposition and/or CO2 concentration. A similar warming impact can be expected in the entire boreal zone, where warming takes place. Given the large size of the boreal biome – more than ten million km2– important climate feedbacks are at stake, such as the future carbon balance, transpiration and albedo. PMID:25383552

Kauppi, Pekka E.; Posch, Maximilian; Pirinen, Pentti

2014-01-01

227

Climate warming affects biological invasions by shifting interactions of plants and herbivores.  

PubMed

Plants and herbivorous insects can each be dramatically affected by temperature. Climate warming may impact plant invasion success directly but also indirectly through changes in their natural enemies. To date, however, there are no tests of how climate warming shifts the interactions among invasive plants and their natural enemies to affect invasion success. Field surveys covering the full latitudinal range of invasive Alternanthera philoxeroides in China showed that a beetle introduced for biocontrol was rare or absent at higher latitudes. In contrast, plant cover and mass increased with latitude. In a 2-year field experiment near the northern limit of beetle distribution, we found the beetle sustained populations across years under elevated temperature, dramatically decreasing A. philoxeroides growth, but it failed to overwinter in ambient temperature. Together, these results suggest that warming will allow the natural enemy to expand its range, potentially benefiting biocontrol in regions that are currently too cold for the natural enemy. However, the invader may also expand its range further north in response to warming. In such cases where plants tolerate cold better than their natural enemies, the geographical gap between plant and herbivorous insect ranges may not disappear but will shift to higher latitudes, leading to a new zone of enemy release. Therefore, warming will not only affect plant invasions directly but also drive either enemy release or increase that will result in contrasting effects on invasive plants. The findings are also critical for future management of invasive species under climate change. PMID:23640751

Lu, Xinmin; Siemann, Evan; Shao, Xu; Wei, Hui; Ding, Jianqing

2013-08-01

228

Innovative empirical approaches for inferring climate-warming impacts on plants in remote areas.  

PubMed

The prediction of the effects of climate warming on plant communities across the globe has become a major focus of ecology, evolution and biodiversity conservation. However, many of the frequently used empirical approaches for inferring how warming affects vegetation have been criticized for decades. In addition, methods that require no electricity may be preferred because of constraints of active warming, e.g. in remote areas. Efforts to overcome the limitations of earlier methods are currently under development, but these approaches have yet to be systematically evaluated side by side. Here, an overview of the benefits and limitations of a selection of innovative empirical techniques to study temperature effects on plants is presented, with a focus on practicality in relatively remote areas without an electric power supply. I focus on methods for: ecosystem aboveground and belowground warming; a fuller exploitation of spatial temperature variation; and long-term monitoring of plant ecological and microevolutionary changes in response to warming. An evaluation of the described methodological set-ups in a synthetic framework along six axes (associated with the consistency of temperature differences, disturbance, costs, confounding factors, spatial scale and versatility) highlights their potential usefulness and power. Hence, further developments of new approaches to empirically assess warming effects on plants can critically stimulate progress in climate-change biology. PMID:25729798

De Frenne, Pieter

2015-02-01

229

Dusting the climate for fingerprints. Has greenhouse warming arrived? Will we ever know?  

SciTech Connect

The topic of global warming is front page news again. Although the annual average global temperature has risen by about 0.5 C since the late 19th century, investigators have had difficulty determining whether natural forces or human actions are to blame. This article summarizes the arguments pro and con and the search for a diffinative `human fingerprint` on global warming. For example, Max-Lanck researchers find it highly imporbable (1 in 20 chance) that natural forcers have caused the temperature rise. However other scientists acknowledge that uncertainties continue to plague studies aimed at detecting the human influence in climatic change. Computer climate models are the major approach, but distiguishing between recent abnormal warming due to greenhouse gases or to other causes is elusive.

Monastersy, R.

1995-06-10

230

Can behavior douse the fire of climate warming? Raymond B. Huey1  

E-print Network

­9) that does just that. Kearny et al. (6) quantify whether a diurnal ectotherm's use of behavioral adjustments-zone ectotherms live in environments that are considerably cooler than their optimum, and so be- coming warmer and continental- desert ectotherms is staying cool. Climate warming will place them at risk, especially if shade

Huey, Raymond B.

231

An Alternative View of the Climate Warming Mitigation Potential of U.S. Temperate Forests  

EPA Science Inventory

Many U.S. federal and non-governmental agencies promote forestation as a means to mitigate climate warming because of the carbon sequestration potential of forests. This biogeochemical-oriented carbon sequestration policy is somewhat inconsistent with a decade or more of researc...

232

Geothermal Evidence From Canada for a Cold Period Before Recent Climatic Warming  

Microsoft Academic Search

Three deep boreholes in a small area in Quebec, each having two high-accuracy temperature logs separated by 22 years, allow reliable determination of the ground surface temperature history during the past few centuries. The temperature logs show that the recent climatic warming was preceded by a cold period near the end of the 19th century in this area. The presence

Kelin Wang; Trevor J. Lewis

1992-01-01

233

Can increased poleward oceanic heat ux explain the warm Cretaceous climate?  

E-print Network

or the poleward oceanic heat ux itself have been prescribed. This implies that the mechanism giving rise1 Can increased poleward oceanic heat ux explain the warm Cretaceous climate? Gavin A. Schmidt Sciences, McGill University, Montreal, Quebec Abstract The poleward transport of heat in the mid

Fridlind, Ann

234

Response of littoral vegetation on climate warming in the boreal zone; an experimental simulation  

Microsoft Academic Search

The impact of climate warming on the littoral zone of a boreal lake ecosystem was studied experimentally for three growing seasons in two artificial ponds (10×27 m) and in replicated chamber experiments. One pond was enclosed in a plastic greenhouse and another untreated pond served as a reference system. During the growing seasons temperature in the greenhouse was maintained at levels

Paula Kankaala; Anne Ojala; Tiina Tulonen; Juha Haapamäki; Lauri Arvola

2000-01-01

235

The tundra warms and grows The effects of climate change on tundra  

E-print Network

ECOLOGY The tundra warms and grows The effects of climate change on tundra in the high Arctic on the tundra of Ellesmere Island in Nunavut, Canada, show an ecosystem `in transition'. Temperatures have risen. But because there was plenty of open ground at the site into which plants could expand, these changes did

236

Response of Lena basin river runoff to recent and projected global climate warming  

Microsoft Academic Search

It follows from the results of calculations fulfilled that in the period of intensive warming of regional climate (beginning with the 1980s) the average annual air temperature rose very considerably, but heterogeneously over the territory of the Lena River basin. The most significant rise is observed in central, eastern and southern parts of the basin. The character of change of

Alexander Georgiadi; Irina Milyukova; Ekaterina Kashutina

2010-01-01

237

Climate warming is lowering levels of dissolved carbon in the Yukon River  

NSDL National Science Digital Library

Dissolved organic carbon (DOC) export, normalized to water discharge, during the growing season from 1978 to 1980 was compared with that taken from 2001 to 2003. It was found that climate warming on frozen soils increases the flow path, residence time, and microbial mineralization of DOC in the soil's active layer and groundwater, ultimately decreasing DOC export.

Striegl et al.

238

Climate change, global warming and coral reefs: Modelling the effects of temperature  

Microsoft Academic Search

Climate change and global warming have severe consequences for the survival of scleractinian (reef-building) corals and their associated ecosystems. This review summarizes recent literature on the influence of temperature on coral growth, coral bleaching, and modelling the effects of high temperature on corals. Satellite-based sea surface temperature (SST) and coral bleaching information available on the internet is an important tool

M. James C. Crabbe

2008-01-01

239

Climatic water deficit and wildfire: predicting spatial patterns in forest ecosystem sensitivity to warming and earlier spring snowmelt. (Invited)  

NASA Astrophysics Data System (ADS)

Western U.S. forest wildfire area burned increased significantly in recent decades, with much of the increase in the US Rocky Mountains (Westerling et al 2006). While Westerling et al (2006) noted that interannual variability in aggregate regional forest wildfire has been highly correlated with regional indices of warming and spring snowmelt, our analysis of the hydroclimatic conditions coincident with the occurrence of large forest wildfires in recent decades reveals that sensitivity of wildfire in specific forest areas has been characterized by a narrow range of climatic conditions: long-term average snow-free season of ~2-4 months and relatively high cumulative water-year actual evapotranspiration (AET). These forests have shown large increases in cumulative water year moisture deficit concomitant with large increases in wildfire in recent years with warmer than average temperatures and earlier spring snowmelt. Forests with high AET and snow-free seasons between 4 and 5 months have exhibited significant but more moderate increases in wildfire activity. Mean snow-free season length and cumulative AET may also be predictive of forest wildfire sensitivity to projected warming. Recent climate change impact studies indicate that the same forests where wildfire activity has exhibited the most sensitivity to observed warming in recent decades may continue to exhibit large increases in the next few decades, until reductions in fuel availability and continuity become dominant constraints on the growth of large wildfires (e.g., Westerling et al 2011a, Litschert et al 2012, Westerling et al unpublished data). We also find that similar forests that may have been buffered from recent climate change by elevation or latitude may also show very large increases in wildfire under projected warming. Conversely, warmer, drier forests where recent changes in moisture deficit and fire activity have been more moderate (particularly those with snow-free seasons ~4-5 months), are projected to experience significant but more moderate increases in forest wildfire activity in response to continued warming (e.g., Krawchuk and Mortiz 2009, Westerling et al 2011b, Rogers et al 2011, Moritz et al 2012). We will present an analysis of hydroclimatic controls on wildfire sensitivity to recent and projected climatic changes, with a particular focus on Rocky mountain forests from the Canadian border through Colorado. Krawchuk, M. A., M. A. Moritz 2012. Fire and Climate Change in California. California Energy Commission CEC-500-2012-026. Litschert, S.E., T.C. Brown, D.M. Theobald 2012. Historic and future extent of wildfires in the Southern Rockies Ecoregion, USA. Forest Ecology and Management, 269:124-133. Moritz, M.A., M.-A. Parisien, E. Batllori, M. A. Krawchuk, J. Van Dorn, D. J. Ganz, & K. Hayhoe 2012. Climate change and disruptions to global fire activity. Ecosphere 3:49. Rogers, Brendan M., et al. 2011. Impacts of climate change on fire regimes and carbon stocks of the US Pacific Northwest. JGR: Biogeosciences (2005-2012) 116.G3. Westerling, A.L., M.G. Turner, E.H. Smithwick, W.H. Romme, M.G. Ryan 2011 (a). Continued warming could transform Greater Yellowstone fire regimes by mid-21st Century. PNAS, 108(32),13165-13170. Westerling, A.L., B.P. Bryant, H.K. Preisler, T.P. Holmes, H. Hidalgo, T. Das, and S. Shrestha 2011 (b). Climate Change and Growth Scenarios for California Wildfire. Climatic Change, 109(s1):445-463.

Westerling, A. L.; Keyser, A.; Milostan, J.

2011-12-01

240

Climatic water deficit and wildfire: predicting spatial patterns in forest ecosystem sensitivity to warming and earlier spring snowmelt. (Invited)  

NASA Astrophysics Data System (ADS)

Western U.S. forest wildfire area burned increased significantly in recent decades, with much of the increase in the US Rocky Mountains (Westerling et al 2006). While Westerling et al (2006) noted that interannual variability in aggregate regional forest wildfire has been highly correlated with regional indices of warming and spring snowmelt, our analysis of the hydroclimatic conditions coincident with the occurrence of large forest wildfires in recent decades reveals that sensitivity of wildfire in specific forest areas has been characterized by a narrow range of climatic conditions: long-term average snow-free season of ~2-4 months and relatively high cumulative water-year actual evapotranspiration (AET). These forests have shown large increases in cumulative water year moisture deficit concomitant with large increases in wildfire in recent years with warmer than average temperatures and earlier spring snowmelt. Forests with high AET and snow-free seasons between 4 and 5 months have exhibited significant but more moderate increases in wildfire activity. Mean snow-free season length and cumulative AET may also be predictive of forest wildfire sensitivity to projected warming. Recent climate change impact studies indicate that the same forests where wildfire activity has exhibited the most sensitivity to observed warming in recent decades may continue to exhibit large increases in the next few decades, until reductions in fuel availability and continuity become dominant constraints on the growth of large wildfires (e.g., Westerling et al 2011a, Litschert et al 2012, Westerling et al unpublished data). We also find that similar forests that may have been buffered from recent climate change by elevation or latitude may also show very large increases in wildfire under projected warming. Conversely, warmer, drier forests where recent changes in moisture deficit and fire activity have been more moderate (particularly those with snow-free seasons ~4-5 months), are projected to experience significant but more moderate increases in forest wildfire activity in response to continued warming (e.g., Krawchuk and Mortiz 2009, Westerling et al 2011b, Rogers et al 2011, Moritz et al 2012). We will present an analysis of hydroclimatic controls on wildfire sensitivity to recent and projected climatic changes, with a particular focus on Rocky mountain forests from the Canadian border through Colorado. Krawchuk, M. A., M. A. Moritz 2012. Fire and Climate Change in California. California Energy Commission CEC-500-2012-026. Litschert, S.E., T.C. Brown, D.M. Theobald 2012. Historic and future extent of wildfires in the Southern Rockies Ecoregion, USA. Forest Ecology and Management, 269:124-133. Moritz, M.A., M.-A. Parisien, E. Batllori, M. A. Krawchuk, J. Van Dorn, D. J. Ganz, & K. Hayhoe 2012. Climate change and disruptions to global fire activity. Ecosphere 3:49. Rogers, Brendan M., et al. 2011. Impacts of climate change on fire regimes and carbon stocks of the US Pacific Northwest. JGR: Biogeosciences (2005-2012) 116.G3. Westerling, A.L., M.G. Turner, E.H. Smithwick, W.H. Romme, M.G. Ryan 2011 (a). Continued warming could transform Greater Yellowstone fire regimes by mid-21st Century. PNAS, 108(32),13165-13170. Westerling, A.L., B.P. Bryant, H.K. Preisler, T.P. Holmes, H. Hidalgo, T. Das, and S. Shrestha 2011 (b). Climate Change and Growth Scenarios for California Wildfire. Climatic Change, 109(s1):445-463.

Westerling, A. L.; Keyser, A.; Milostan, J.

2013-12-01

241

Simulated climate warming alters phenological synchrony between an outbreak insect herbivore and host trees.  

PubMed

As the world's climate warms, the phenologies of interacting organisms in seasonally cold environments may advance at differing rates, leading to alterations in phenological synchrony that can have important ecological consequences. For temperate and boreal species, the timing of early spring development plays a key role in plant-herbivore interactions and can influence insect performance, outbreak dynamics, and plant damage. We used a field-based, meso-scale free-air forest warming experiment (B4WarmED) to examine the effects of elevated temperature on the phenology and performance of forest tent caterpillar (Malacosoma disstria) in relation to the phenology of two host trees, aspen (Populus tremuloides) and birch (Betula papyrifera). Results of our 2-year study demonstrated that spring phenology advanced for both insects and trees, with experimentally manipulated increases in temperature of 1.7 and 3.4 °C. However, tree phenology advanced more than insect phenology, resulting in altered phenological synchrony. Specifically, we observed a decrease in the time interval between herbivore egg hatch and budbreak of aspen in both years and birch in one year. Moreover, warming decreased larval development time from egg hatch to pupation, but did not affect pupal mass. Larvae developed more quickly on aspen than birch, but pupal mass was not affected by host species. Our study reveals that warming-induced phenological shifts can alter the timing of ecological interactions across trophic levels. These findings illustrate one mechanism by which climate warming could mediate insect herbivore outbreaks, and also highlights the importance of climate change effects on trophic interactions. PMID:24889969

Schwartzberg, Ezra G; Jamieson, Mary A; Raffa, Kenneth F; Reich, Peter B; Montgomery, Rebecca A; Lindroth, Richard L

2014-07-01

242

Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.  

PubMed

Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. PMID:24343906

de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

2014-07-01

243

Climatic warming in the Tibetan Plateau during recent decades  

Microsoft Academic Search

Adequate knowledge of climatic change over the Tibetan Plateau (TP) with an average elevation of more than 4000 m above sea level (a.s.l.) has been insufficient for a long time owing to the lack of sufficient observational data. In the present study, monthly surface air temperature data were collected from almost every meteorological station on the TP since their establishment.

Xiaodong Liu; Baode Chen

2000-01-01

244

Humidity critical for grass growth in warming climates  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant growth responses to climate change might be confounded by multi-factor changes such as temperature and vapor pressure deficit (VPD). The growth and water loss of tall fescue (Festuca arundinaccea Schreb.), a cool season grass, was measured over 6 weeks with independent control of temperature a...

245

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01

246

Photosynthesis of temperate Eucalyptus globulus trees outside their native range has limited adjustment to elevated CO2 and climate warming.  

PubMed

Eucalyptus species are grown widely outside of their native ranges in plantations on all vegetated continents of the world. We predicted that such a plantation species would show high potential for acclimation of photosynthetic traits across a wide range of growth conditions, including elevated [CO2] and climate warming. To test this prediction, we planted temperate Eucalyptus globulus Labill. seedlings in climate-controlled chambers in the field located >700 km closer to the equator than the nearest natural occurrence of this species. Trees were grown in a complete factorial combination of elevated CO2 concentration (eC; ambient [CO2] +240 ppm) and air warming treatments (eT; ambient +3 °C) for 15 months until they reached ca. 10 m height. There was little acclimation of photosynthetic capacity to eC and hence the CO2-induced photosynthetic enhancement was large (ca. 50%) in this treatment during summer. The warming treatment significantly increased rates of both carboxylation capacity (V(cmax)) and electron transport (Jmax) (measured at a common temperature of 25 °C) during winter, but decreased them significantly by 20-30% in summer. The photosynthetic CO2 compensation point in the absence of dark respiration (?*) was relatively less sensitive to temperature in this temperate eucalypt species than for warm-season tobacco. The temperature optima for photosynthesis and Jmax significantly changed by about 6 °C between winter and summer, but without further adjustment from early to late summer. These results suggest that there is an upper limit for the photosynthetic capacity of E. globulus ssp. globulus outside its native range to acclimate to growth temperatures above 25 °C. Limitations to temperature acclimation of photosynthesis in summer may be one factor that defines climate zones where E. globulus plantation productivity can be sustained under anticipated global environmental change. PMID:23824839

Crous, Kristine Y; Quentin, Audrey G; Lin, Yan-Shih; Medlyn, Belinda E; Williams, David G; Barton, Craig V M; Ellsworth, David S

2013-12-01

247

Impacts of peatland forestation on regional climate conditions in Finland  

NASA Astrophysics Data System (ADS)

Climate response to anthropogenic land cover change happens more locally and occurs on a shorter time scale than the global warming due to increased GHGs. Over the second half of last Century, peatlands were vastly drained in Finland to stimulate forest growth for timber production. In this study, we investigate the biophysical effects of peatland forestation on near-surface climate conditions in Finland. For this, the regional climate model REMO, developed in Max Plank Institute (currently in Climate Service Center, Germany), provides an effective way. Two sets of 15-year climate simulations were done by REMO, using the historic (1920s; The 1st Finnish National Forest Inventory) and present-day (2000s; the 10th Finnish National Forest Inventory) land cover maps, respectively. The simulated surface air temperature and precipitation were then analyzed. In the most intensive peatland forestation area in Finland, the differences in monthly averaged daily mean surface air temperature show a warming effect around 0.2 to 0.3 K in February and March and reach to 0.5 K in April, whereas a slight cooling effect, less than 0.2 K, is found from May till October. Consequently, the selected snow clearance dates in model gridboxes over that area are advanced 0.5 to 4 days in the mean of 15 years. The monthly averaged precipitation only shows small differences, less than 10 mm/month, in a varied pattern in Finland from April to September. Furthermore, a more detailed analysis was conducted on the peatland forestation area with a 23% decrease in peatland and a 15% increase in forest types. 11 day running means of simulated temperature and energy balance terms, as well as snow depth were averaged over 15 years. Results show a positive feedback induced by peatland forestation between the surface air temperature and snow depth in snow melting period. This is because the warmer temperature caused by lower surface albedo due to more forest in snow cover period leads to a quicker and earlier snow melting. Meanwhile, surface albedo is reduced and consequently surface air temperature is increased. Additionally, the maximum difference from individual gridboxes in this area over 15 years of 11 day running means of daily mean surface air temperature reaches 2 K, which is four times as much as the maximum difference of 15-year regional average of that. This illustrates that the spring warming effect from peatland forestation in Finland is highly heterogeneous spatially and temporally.

Gao, Yao; Markkanen, Tiina; Backman, Leif; Henttonen, Helena M.; Pietikäinen, Joni-Pekka; Laaksonen, Ari

2014-05-01

248

[Effects of climate warming and drying on millet yield in Gansu Province and related countermeasures].  

PubMed

Based on the data of air temperature, precipitation, and millet yield from Ganzhou, Anding, and Xifeng, the representative stations in Hexi moderate arid oasis irrigation area, moderate sub-arid dry area in middle Gansu, and moderate sub-humid dry area in eastern Gansu, respectively, this paper calculated the regional active accumulated temperature of > or = 0 degrees C, > or =5 degrees C, > or =10 degrees C, > or =15 degrees C, and > or =20 degrees C in millet growth period, and the average temperature and precipitation in millet key growth stages. The millet climatic yield was isolated by orthogonal polynomial, and the change characteristics of climate and millet climatic yield as well as the effects of climate change on millet yield were analyzed by statistical methods of linear tendency, cumulative anomaly, and Mann-Kendall. The results showed that warming and drying were the main regional features in the modern climatic change of Gansu. The regional temperature had a significant upward trend since the early 1990s, while the precipitation was significantly reduced from the late 1980s. There were significant correlations between millet yield and climatic factors. The millet yield in dry areas increased with the increasing temperature and precipitation in millet key growth stages, and that in Hexi Corridor area increased with increasing temperature. Warming and drying affected millet yield prominently. The weather fluctuation index of regional millet yield in Xifeng, Anding, and Ganzhou accounted for 73%, 72%, and 54% of real output coefficient variation, respectively, and the percentages increased significantly after warming. Warming was conducive to the increase of millet production, and the annual increment of millet climatic yield in Xifeng, Anding, and Ganzhou after warming was 30.6, 43.1, and 121.1 kg x hm(-2), respectively. Aiming at the warming and drying trend in Gansu Province in the future, the millet planting area in the Province should be further expanded, and the millet planting structure should be adjusted. At the same time, according to the different regional and yearly climatic types, different varieties should be selected, and various planting measures should be taken. PMID:21361020

Cao, Ling; Wang, Qiang; Deng, Zhen-yong; Guo, Xiao-qin; Ma, Xing-xiang; Ning, Hui-fang

2010-11-01

249

Climate warming increases biological control agent impact on a non-target species.  

PubMed

Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species. PMID:25376303

Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing

2015-01-01

250

Climate warming increases biological control agent impact on a non-target species  

PubMed Central

Climate change may shift interactions of invasive plants, herbivorous insects and native plants, potentially affecting biological control efficacy and non-target effects on native species. Here, we show how climate warming affects impacts of a multivoltine introduced biocontrol beetle on the non-target native plant Alternanthera sessilis in China. In field surveys across a latitudinal gradient covering their full distributions, we found beetle damage on A. sessilis increased with rising temperature and plant life history changed from perennial to annual. Experiments showed that elevated temperature changed plant life history and increased insect overwintering, damage and impacts on seedling recruitment. These results suggest that warming can shift phenologies, increase non-target effect magnitude and increase non-target effect occurrence by beetle range expansion to additional areas where A. sessilis occurs. This study highlights the importance of understanding how climate change affects species interactions for future biological control of invasive species and conservation of native species. PMID:25376303

Lu, Xinmin; Siemann, Evan; He, Minyan; Wei, Hui; Shao, Xu; Ding, Jianqing

2015-01-01

251

GLOBAL CLIMATE CHANGE TRIGGERED BY GLOBAL WARMING A POSITION PAPER FROM THE CENTER FOR INQUIRY  

E-print Network

for this material to be shared for noncommercial, educational purposes, provided that this notice appears on the reproduced materials, the full authoritative version is retained, and copies are not altered. To disseminate otherwise or to republish requires written permission from the Center for Inquiry, Inc. GLOBAL CLIMATE CHANGE TRIGGERED BY GLOBAL WARMING EXECUTIVE SUMMARY This paper will offer compelling evidence from a large body of research that global climate change caused by global warming is already underway and requires our immediate attention. The research in question appears in refereed scientific literature, and most of it reflects a broad consensus of the worldwide climatology community. The principal points of this position paper are summarized below and are considered in detail, with supporting references, in the text that follows. Convincing evidence that the Earth’s climate is undergoing significant, and in some cases alarming, changes has accumulated rapidly in recent years, especially during the past three decades.

unknown authors

252

Simulated Changes in the Freezing Rain Climatology of North America under Global Warming Using a Coupled Climate Model  

Microsoft Academic Search

A precipitation typing algorithm was applied to climate model simulations in order to investigate the effect of global warming on the occurrence of freezing rain over North America. The model used in the study was the Canadian Centre for Climate Modelling and Analysis' CGCM3. Two realizations of the present-day (1981–2000) climate and two realizations of a global warming (2081–2100) simulation

Steven J. Lambert; Bjarne K. Hansen

2011-01-01

253

Permafrost degradation and methane: low risk of biogeochemical climate-warming feedback  

NASA Astrophysics Data System (ADS)

Climate change and permafrost thaw have been suggested to increase high latitude methane emissions that could potentially represent a strong feedback to the climate system. Using an integrated earth-system model framework, we examine the degradation of near-surface permafrost, temporal dynamics of inundation (lakes and wetlands) induced by hydro-climatic change, subsequent methane emission, and potential climate feedback. We find that increases in atmospheric CH4 and its radiative forcing, which result from the thawed, inundated emission sources, are small, particularly when weighed against human emissions. The additional warming, across the range of climate policy and uncertainties in the climate-system response, would be no greater than 0.1?° C by 2100. Further, for this temperature feedback to be doubled (to approximately 0.2?° C) by 2100, at least a 25-fold increase in the methane emission that results from the estimated permafrost degradation would be required. Overall, this biogeochemical global climate-warming feedback is relatively small whether or not humans choose to constrain global emissions.

Gao, Xiang; Schlosser, C. Adam; Sokolov, Andrei; Anthony, Katey Walter; Zhuang, Qianlai; Kicklighter, David

2013-09-01

254

Quantifying greenhouse warming, aerosol cooling and the transient climate sensitivity - A novel approach  

NASA Astrophysics Data System (ADS)

We present an interdisciplinary study combining climate observations and modeling with econometric methodology to identify the relative contributions to recent climate change from greenhouse warming and aerosol cooling. The cooling effect of aerosols has likely masked some of the warming due to increasing GHG concentrations to date. Several publications have recently pointed out the intimate relationship between the aerosol cooling effect and climate sensitivity. Generally, a GCM that has a large aerosol cooling effect will typically have a high climate sensitivity, and vice versa. Given this connection between the aerosol effect and the GCMs climate sensitivity, it is problematic that the aerosol effect is still very poorly constrained, even after decades of dedicated research on aerosol effects on climate. It is time to seek out other complimentary and parallel approaches to the traditional ones, and this is at the heart of the presented study. We apply econometric methods to determine the parameters of an energy balance model, using observed time series of surface air temperature, radiation and CO2 concentrations. This framework allows us to decompose of the observed temperature trend into a GHG component and an aerosol component for the time period 1960 to 2000. We find that aerosols have likely masked about 50% of the warming due to increasing GHG concentrations during this time period. This is compared to a much weaker aerosol masking simulated by the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM). The framework also allows for an estimate of the transient climate sensitivity, with the caveat that the estimate is only valid for the parts of the globe which have sufficient data coverage to be included in our analysis. This is the case for most land areas, for which our framework yields a transient climate sensitivity of 6.1K, with a 95% confidence interval of [3.6, 8.7]K.

Storelvmo, T.; Leirvik, T.; Phillips, P.; Turrini, A.

2013-12-01

255

Adaptive strategies and life history characteristics in a warming climate: salmon in the Arctic?  

USGS Publications Warehouse

In the warming Arctic, aquatic habitats are in flux and salmon are exploring their options. Adult Pacific salmon, including sockeye (Oncorhynchus nerka), coho (O. kisutch), Chinook (O. tshawytscha), pink (O. gorbuscha) and chum (O. keta) have been captured throughout the Arctic. Pink and chum salmon are the most common species found in the Arctic today. These species are less dependent on freshwater habitats as juveniles and grow quickly in marine habitats. Putative spawning populations are rare in the North American Arctic and limited to pink salmon in drainages north of Point Hope, Alaska, chum salmon spawning rivers draining to the northwestern Beaufort Sea, and small populations of chum and pink salmon in Canada’s Mackenzie River. Pacific salmon have colonized several large river basins draining to the Kara, Laptev and East Siberian seas in the Russian Arctic. These populations probably developed from hatchery supplementation efforts in the 1960’s. Hundreds of populations of Arctic Atlantic salmon (Salmo salar) are found in Russia, Norway and Finland. Atlantic salmon have extended their range eastward as far as the Kara Sea in central Russian. A small native population of Atlantic salmon is found in Canada’s Ungava Bay. The northern tip of Quebec seems to be an Atlantic salmon migration barrier for other North American stocks. Compatibility between life history requirements and ecological conditions are prerequisite for salmon colonizing Arctic habitats. Broad-scale predictive models of climate change in the Arctic give little information about feedback processes contributing to local conditions, especially in freshwater systems. This paper reviews the recent history of salmon in the Arctic and explores various patterns of climate change that may influence range expansions and future sustainability of salmon in Arctic habitats. A summary of the research needs that will allow informed expectation of further Arctic colonization by salmon is given.

Nielsen, Jennifer L.; Ruggerone, Gregory T.; Zimmerman, Christian E.

2013-01-01

256

Personal efficacy, the information environment, and attitudes toward global warming and climate change in the united states. Risk Analysis  

E-print Network

Despite the growing scientific consensus about the risks of global warming and climate change, the mass media frequently portray the subject as one of great scientific controversy and debate. And yet previous studies of the mass public’s subjective assessments of the risks of global warming and climate change have not sufficiently examined public informedness, public confidence in climate scientists, and the role of personal efficacy in affecting global warming outcomes. By examining the results of a survey on an original and representative sample of Americans, we find that these three forces—informedness, confidence in scientists, and personal efficacy—are related in interesting and unexpected ways, and exert significant influence on risk assessments of global warming and climate change. In particular, more informed respondents both feel less personally responsible for global warming, and also show less concern for global warming. We also find that confidence in scientists has unexpected effects: respondents with high confidence in scientists feel less responsible for global warming, and also show less concern for global warming. These results have substantial implications for the interaction between scientists and the public in general, and for the public discussion of global warming and climate change in particular.

Paul M. Kellstedt; Sammy Zahran; Arnold Vedlitz

2008-01-01

257

Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions.  

PubMed

Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing. PMID:23980249

Godbold, Jasmin A; Solan, Martin

2013-01-01

258

Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions  

PubMed Central

Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing. PMID:23980249

Godbold, Jasmin A.; Solan, Martin

2013-01-01

259

A brief history of climate - the northern seas from the Last Glacial Maximum to global warming  

NASA Astrophysics Data System (ADS)

The understanding of climate and climate change is fundamentally concerned with two things: a well-defined and sufficiently complete climate record to be explained, for example of observed temperature, and a relevant mechanistic framework for making closed and consistent inferences concerning cause-and-effect. This is the case for understanding observed climate, as it is the case for historical climate as reconstructed from proxy data and future climate as projected by models. The present study offers a holistic description of northern maritime climate - from the Last Glacial Maximum through to the projected global warming of the 21st century - in this context. It includes the compilation of the most complete temperature record for Norway and the Norwegian Sea to date based on the synthesis of available terrestrial and marine paleoclimate reconstructions into continuous times series, and their continuation into modern and future climate with the instrumental record and a model projection. The scientific literature on a variable northern climate is reviewed against this background, and with a particular emphasis on the role of the Norwegian Atlantic Current - the Gulf Stream's extension towards the Arctic. This includes the introduction of an explicit and relatively simple diagnostic relation to quantify the change in ocean circulation consistent with reconstructed ocean temperatures. It is found that maritime climate and the strength of the Norwegian Atlantic Current are closely related throughout the record. The nature of the relation is however qualitatively different as one progresses from the past, through the present, and into the future.

Eldevik, Tor; Risebrobakken, Bjørg; Bjune, Anne E.; Andersson, Carin; Birks, H. John B.; Dokken, Trond M.; Drange, Helge; Glessmer, Mirjam S.; Li, Camille; Nilsen, Jan Even Ø.; Otterå, Odd Helge; Richter, Kristin; Skagseth, Øystein

2014-12-01

260

McMurdo Dry Valleys Climate Response to Plio-Pleistocene Warm Interglacial Climate Forcing  

NASA Astrophysics Data System (ADS)

The Antarctic Drilling Program recovered high quality Neogene sediment cores off of the coast of Ross Island recording a series of ice-contact, ice-proximal, ice-distal and marine facies suggesting grounding line migration along the sea floor. Chronology control of the core places glacial variability consistent with ~41 kyr orbital forcing. The marine facies suggests episodes of open-water conditions and elevated sea-surface temperatures in McMurdo Sound and the Ross Sea during the Pliocene. Recent Antarctic ice sheet modeling efforts have supported episodic retreat of the sea ice and possibly a frequent collapse of the West Antarctic Ice Sheet (WAIS) during the warmest intervals of the Pliocene-Pleistocene. Such repeated reduction in the Antarctic Ice Sheets occurs at a time when terrestrial records from near-by McMurdo Dry Valleys call for enduring hyper-arid cold desert conditions since the mid-to early Miocene. To assess whether hyper-arid cold desert climate could exist at high elevations within the McMurdo Dry Valleys during episodes of a diminished ice sheet (and near-by open water conditions), or if in fact these conditions are mutually exclusive, we simulated both present day (for validation) and paleo-climate conditions for Antarctic using a high resolution Regional Climate Model (RegCM3) nested within a medium resolution Global Climate Model (GCM) to predict paleo-climate as a function of ice sheet variability. RegCM3 simulations for paleo-conditions focused on the response of the Ross Sea sector to 1) orbital changes consistent with peak austral summer warmth, 2) reduction of ice shelves including the loss of the Ross and Filchner-Ronne Ice Shelves, 3) higher than modern carbon dioxide concentrations (400 - 800 ppmv) and 4) a highly diminished WAIS as predicted by the ice-sheet model. Results show mean atmospheric temperatures in the McMurdo Dry Valleys are most sensitive to loss of sea ice in McMurdo Sound / Ross Sea. If we assume a loss of marine grounded ice and remove the Antarctic ice shelves the mean atmospheric temperatures in the McMurdo Dry Valleys increases; model results suggest temperatures were 2.78°C and 2.38°C warmer than today at the coast and inland respectively although the rise in atmospheric temperatures during the summer months is typically of a smaller magnitude compared to the temperature rise predicted for the winter months. As expected the model showed warmer mean atmospheric temperatures with elevated levels of CO2. Precipitation also increased in the McMurdo Dry Valleys with increasing values of CO2. Initial model results for simulations run with a diminished WAIS predict increased atmospheric temperatures for most of the continent; temperature increase within the Transantarctic Mountains and McMurdo Dry Valleys is below the mean rise in Antarctic temperature for this simulation.

Kowalewski, D. E.; Deconto, R.; Seth, A.; Pollard, D.

2010-12-01

261

Climate Warming and 21st-Century Drought in Southwestern North America  

NASA Astrophysics Data System (ADS)

Since 2000, southwestern North America has experienced widespread drought. Lakes Powell and Mead are now at less than 50% of their reservoir capacity, and drought or fire-related states of emergency were declared this past summer by governors in six western states. As with other prolonged droughts, such as the Dust Bowl during the 1930s, aridity has at times extended from northern Mexico to the southern Canadian prairies. A synthesis of climatological and paleoclimatological studies suggests that a transition to a more arid climate may be occurring due to global warming, with the prospect of sustained droughts being exacerbated by the potential reaction of the Pacific Ocean to warming.

MacDonald, Glen M.; Stahle, David W.; Diaz, Jose Villanueva; Beer, Nicholas; Busby, Simon J.; Cerano-Paredes, Julian; Cole, Julie E.; Cook, Edward R.; Endfield, Georgina; Gutierrez-Garcia, Genaro; Hall, Beth; Magana, Victor; Meko, David M.; Méndez-Pérez, Matias; Sauchyn, David J.; Watson, Emma; Woodhouse, Connie A.

2008-02-01

262

Is This Global Warming? Communicating the Intangibles of Climate Change  

NASA Astrophysics Data System (ADS)

Unlike weather, which is immediate, tangible, and relevant on a daily basis, climate change is long-term, slow to evolve, and often difficult to relate to the public's daily concerns. By explaining global-change research to wide and diverse audiences through a variety of vehicles, including publications, exhibits, Web sites, and television B-roll, UCAR has gained experience and perspective on the challenges involved. This talk will explore some of the lessons learned and some of the key difficulties that face global-change communicators, including: --The lack of definitive findings on regional effects of global change -- The long time frame in which global change plays out, versus the short attention span of media, the public, and policy makers --The use of weather events as news pegs (they pique interest, but they may not be good exemplars of global change and are difficult to relate directly to changes in greenhouse-gas emissions) --The perils of the traditional journalistic technique of point-counterpoint in discussing climate change --The presence of strong personal/political convictions among various interest groups and how these affect the message(s) conveyed

Warner, L.; Henson, R.

2004-05-01

263

A regional response in mean westerly circulation and rainfall to projected climate warming over Tasmania, Australia  

NASA Astrophysics Data System (ADS)

Coupled ocean-atmosphere general circulation models (GCMs) lack sufficient resolution to model the regional detail of changes to mean circulation and rainfall with projected climate warming. In this paper, changes in mean circulation and rainfall in GCMs are compared to those in a variable resolution regional climate model, the Conformal Cubic Atmospheric Model (CCAM), under a high greenhouse gas emissions scenario. The study site is Tasmania, Australia, which is positioned within the mid-latitude westerlies of the southern hemisphere. CCAM projects a different response in mean sea level pressure and mid-latitude westerly circulation to climate warming to the GCMs used as input, and shows greater regional detail of the boundaries between regions of increasing and decreasing rainfall. Changes in mean circulation dominate the mean rainfall response in western Tasmania, whereas changes to rainfall in the East Coast are less related to mean circulation changes. CCAM projects an amplification of the dominant westerly circulation over Tasmania and this amplifies the seasonal cycle of wet winters and dry summers in the west. There is a larger change in the strength than in the incidence of westerly circulation and rainfall events. We propose the regional climate model displays a more sensitive atmospheric response to the different rates of warming of land and sea than the GCMs as input. The regional variation in these results highlight the need for dynamical downscaling of coupled general circulation models to finely resolve the influence of mean circulation and boundaries between regions of projected increases and decreases in rainfall.

Grose, Michael R.; Corney, Stuart P.; Katzfey, Jack J.; Bennett, James C.; Holz, Gregory K.; White, Christopher J.; Bindoff, Nathaniel L.

2013-04-01

264

Warming-induced increase in aerosol number concentration likely to moderate climate change  

NASA Astrophysics Data System (ADS)

Atmospheric aerosol particles influence the climate system directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. Apart from black carbon aerosol, aerosols cause a negative radiative forcing at the top of the atmosphere and substantially mitigate the warming caused by greenhouse gases. In the future, tightening of controls on anthropogenic aerosol and precursor vapour emissions to achieve higher air quality may weaken this beneficial effect. Natural aerosols, too, might affect future warming. Here we analyse long-term observations of concentrations and compositions of aerosol particles and their biogenic precursor vapours in continental mid- and high-latitude environments. We use measurements of particle number size distribution together with boundary layer heights derived from reanalysis data to show that the boundary layer burden of cloud condensation nuclei increases exponentially with temperature. Our results confirm a negative feedback mechanism between the continental biosphere, aerosols and climate: aerosol cooling effects are strengthened by rising biogenic organic vapour emissions in response to warming, which in turn enhance condensation on particles and their growth to the size of cloud condensation nuclei. This natural growth mechanism produces roughly 50% of particles at the size of cloud condensation nuclei across Europe. We conclude that biosphere-atmosphere interactions are crucial for aerosol climate effects and can significantly influence the effects of anthropogenic aerosol emission controls, both on climate and air quality.

Paasonen, Pauli; Asmi, Ari; Petäjä, Tuukka; Kajos, Maija K.; Äijälä, Mikko; Junninen, Heikki; Holst, Thomas; Abbatt, Jonathan P. D.; Arneth, Almut; Birmili, Wolfram; van der Gon, Hugo Denier; Hamed, Amar; Hoffer, András; Laakso, Lauri; Laaksonen, Ari; Richard Leaitch, W.; Plass-Dülmer, Christian; Pryor, Sara C.; Räisänen, Petri; Swietlicki, Erik; Wiedensohler, Alfred; Worsnop, Douglas R.; Kerminen, Veli-Matti; Kulmala, Markku

2013-06-01

265

Potential impacts of climate warming on water supply reliability in the Tuolumne and Merced River Basins, California.  

PubMed

We present an integrated hydrology/water operations simulation model of the Tuolumne and Merced River Basins, California, using the Water Evaluation and Planning (WEAP) platform. The model represents hydrology as well as water operations, which together influence water supplied for agricultural, urban, and environmental uses. The model is developed for impacts assessment using scenarios for climate change and other drivers of water system behavior. In this paper, we describe the model structure, its representation of historical streamflow, agricultural and urban water demands, and water operations. We describe projected impacts of climate change on hydrology and water supply to the major irrigation districts in the area, using uniform 2 °C, 4 °C, and 6 °C increases applied to climate inputs from the calibration period. Consistent with other studies, we find that the timing of hydrology shifts earlier in the water year in response to temperature warming (5-21 days). The integrated agricultural model responds with increased water demands 2 °C (1.4-2.0%), 4 °C (2.8-3.9%), and 6 °C (4.2-5.8%). In this sensitivity analysis, the combination of altered hydrology and increased demands results in decreased reliability of surface water supplied for agricultural purposes, with modeled quantity-based reliability metrics decreasing from a range of 0.84-0.90 under historical conditions to 0.75-0.79 under 6 °C warming scenario. PMID:24465455

Kiparsky, Michael; Joyce, Brian; Purkey, David; Young, Charles

2014-01-01

266

Indian Ocean warming during 1958-2004 simulated by a climate system model and its mechanism  

NASA Astrophysics Data System (ADS)

The mechanism responsible for Indian Ocean Sea surface temperature (SST) basin-wide warming trend during 1958-2004 is studied based on both observational data analysis and numerical experiments with a climate system model FGOALS-gl. To quantitatively estimate the relative contributions of external forcing (anthropogenic and natural forcing) and internal variability, three sets of numerical experiments are conducted, viz. an all forcing run forced by both anthropogenic forcing (greenhouse gases and sulfate aerosols) and natural forcing (solar constant and volcanic aerosols), a natural forcing run driven by only natural forcing, and a pre-industrial control run. The model results are compared to the observations. The results show that the observed warming trend during 1958-2004 (0.5 K (47-year)-1) is largely attributed to the external forcing (more than 90 % of the total trend), while the residual is attributed to the internal variability. Model results indicate that the anthropogenic forcing accounts for approximately 98.8 % contribution of the external forcing trend. Heat budget analysis shows that the surface latent heat flux due to atmosphere and surface longwave radiation, which are mainly associated with anthropogenic forcing, are in favor of the basin-wide warming trend. The basin-wide warming is not spatially uniform, but with an equatorial IOD-like pattern in climate model. The atmospheric processes, oceanic processes and climatological latent heat flux together form an equatorial IOD-like warming pattern, and the oceanic process is the most important in forming the zonal dipole pattern. Both the anthropogenic forcing and natural forcing result in easterly wind anomalies over the equator, which reduce the wind speed, thereby lead to less evaporation and warmer SST in the equatorial western basin. Based on Bjerknes feedback, the easterly wind anomalies uplift the thermocline, which is unfavorable to SST warming in the eastern basin, and contribute to SST warming via deeper thermocline in the western basin. The easterly anomalies also drive westward anomalous equatorial currents, against the eastward climatology currents, which is in favor of the SST warming in the western basin via anomalous warm advection. Therefore, both the atmospheric and oceanic processes are in favor of the IOD-like warming pattern formation over the equator.

Dong, Lu; Zhou, Tianjun; Wu, Bo

2014-01-01

267

Global warming is breeding social conflict: The subtle impact of climate change threat on authoritarian tendencies  

Microsoft Academic Search

Climate change can increase societies’ propensity to conflict by changes in socio-structural conditions (e.g., resource scarcity, migration). We propose an additional, subtle, and general effect of climate change threat via increases in authoritarian attitudes. Three studies in Germany and the UK support this suggestion. Reminding participants of the adverse consequences climate change may have for their country increased the derogation

Immo Fritsche; J. Christopher Cohrs; Thomas Kessler; Judith Bauer

268

Climate warming could reduce runoff significantly in New England, USA  

USGS Publications Warehouse

The relation between mean annual temperature (MAT), mean annual precipitation (MAP) and evapotranspiration (ET) for 38 forested watersheds was determined to evaluate the potential increase in ET and resulting decrease in stream runoff that could occur following climate change and lengthening of the growing season. The watersheds were all predominantly forested and were located in eastern North America, along a gradient in MAT from 3.5??C in New Brunswick, CA, to 19.8??C in northern Florida. Regression analysis for MAT versus ET indicated that along this gradient ET increased at a rate of 2.85 cm??C-1 increase in MAT (??0.96 cm??C-1, 95% confidence limits). General circulation models (GCM) using current mid-range emission scenarios project global MAT to increase by about 3??C during the 21st century. The inferred, potential, reduction in annual runoff associated with a 3??C increase in MAT for a representative small coastal basin and an inland mountainous basin in New England would be 11-13%. Percentage reductions in average daily runoff could be substantially larger during the months of lowest flows (July-September). The largest absolute reductions in runoff are likely to be during April and May with smaller reduction in the fall. This seasonal pattern of reduction in runoff is consistent with lengthening of the growing season and an increase in the ratio of rain to snow. Future increases in water use efficiency (WUE), precipitation, and cloudiness could mitigate part or all of this reduction in runoff but the full effects of changing climate on WUE remain quite uncertain as do future trends in precipitation and cloudiness.

Huntington, T.G.

2003-01-01

269

Impact of CO2Induced Warming on Simulated Hurricane Intensity and Precipitation: Sensitivity to the Choice of Climate Model and Convective Parameterization  

Microsoft Academic Search

Previous studies have found that idealized hurricanes, simulated under warmer, high-CO 2 conditions, are more intense and have higher precipitation rates than under present-day conditions. The present study explores the sensitivity of this result to the choice of climate model used to define the CO2-warmed environment and to the choice of convective parameterization used in the nested regional model that

Thomas R. Knutson; Robert E. Tuleya

2004-01-01

270

Correlation between recruitment and fall condition of age-0 pollock (Theragra chalcogramma) from the eastern Bering Sea under varying climate conditions  

NASA Astrophysics Data System (ADS)

Fishery managers require an understanding of how climate influences recruitment if they are to separate the effects of fishing and climate on production. The southeastern Bering Sea offers opportunities to understand climate effects on recruitment because inter-annual oscillations in ice coverage set up warm or cold conditions for juvenile fish production. Depth-averaged temperature anomalies in the Bering Sea indicate the past nine years have included three warm (2003-2005), an average (2006), and five cold (2007-2011) years. We examined how these climatic states influenced the diet quality and condition (size, energy density and total energy) of young-of-the-year (YOY) pollock (Theragra chalcogramma) in fall. The implications of fall condition were further examined by relating condition prior to winter to the number of age-1 recruits-per-spawner the following summer (R/S). The percentage of lipid in pollock diets was threefold higher in cold years compared with warm years, but stomach fullness did not vary. Consequently, fish energy densities were 33% higher in cold years (P<0.001) than in warm years. In contrast, neither fish size (P=0.666), nor total energy (P=0.197) varied with climatic condition. However, total energy was significantly (P=0.007) and positively correlated with R/S (R2=0.736). We conclude that recruitment to age-1 in the southeastern Bering Sea is improved under environmental conditions that produce large, energy dense YOY pollock in fall.

Heintz, Ron A.; Siddon, Elizabeth C.; Farley, Edward V.; Napp, Jeffrey M.

2013-10-01

271

Climate. Varying planetary heat sink led to global-warming slowdown and acceleration.  

PubMed

A vacillating global heat sink at intermediate ocean depths is associated with different climate regimes of surface warming under anthropogenic forcing: The latter part of the 20th century saw rapid global warming as more heat stayed near the surface. In the 21st century, surface warming slowed as more heat moved into deeper oceans. In situ and reanalyzed data are used to trace the pathways of ocean heat uptake. In addition to the shallow La Niña-like patterns in the Pacific that were the previous focus, we found that the slowdown is mainly caused by heat transported to deeper layers in the Atlantic and the Southern oceans, initiated by a recurrent salinity anomaly in the subpolar North Atlantic. Cooling periods associated with the latter deeper heat-sequestration mechanism historically lasted 20 to 35 years. PMID:25146282

Chen, Xianyao; Tung, Ka-Kit

2014-08-22

272

Spatiotemporal change in geographical distribution of global climate types in the context of climate warming  

NASA Astrophysics Data System (ADS)

After standardizing global land climate gridded data from the Climatic Research Unit TS (time-series) 3.1 dataset for the period 1901-2009, cluster analysis is used to objectively classify world climates into 14 climate types. These climate types establish a baseline classification map and the types are named according to Köppen-Geiger climate classifications. Although the cluster analysis and Köppen classification methods are very different, the distributions of climate types obtained by the two methods are similar. Moreover, the climate types we identify also coincide well with their corresponding vegetation types. Thus, cluster analysis can be used as an effective alternative to the Köppen classification method for classifying world climate types. The spatial and temporal changes in geographical distribution of global climate types were investigated in 25-year intervals, and Cohen's kappa coefficient is used to detect agreement between the periods. Globally, although an obvious trend in increasing global temperature is found, distribution of climate types overall show no distinct changes over the periods. However, at the regional scale, spatial change in distribution of climate types is evident in South America and Africa. In South America, larger areas of the "fully humid equatorial rainforest" (Af) and "equatorial savannah with dry winter" (Aw) climate types have changed types. In Africa, changes mainly occurred in the Af, "equatorial savannah with dry summer" (As), Aw, "steppe climate" (BS), and "desert climate" (BW) climate types. Moreover, some climate types, including Af, "equatorial monsoon" (Am), BS, BW, and "tundra climate" (ET), were susceptible to temporal climate changes, especially in the period 1976-2009.

Zhang, Xianliang; Yan, Xiaodong

2014-08-01

273

Enhanced Climatic Warming in the Tibetan Plateau Due to Double CO2: A Model Study  

NASA Technical Reports Server (NTRS)

The NCAR (National Center for Atmospheric Research) regional climate model (RegCM2) with time-dependent lateral meteorological fields provided by a 130-year transient increasing CO2 simulation of the NCAR Climate System Model (CSM) has been used to investigate the mechanism of enhanced ground temperature warming over the TP (Tibetan Plateau). From our model results, a remarkable tendency of warming increasing with elevation is found for the winter season, and elevation dependency of warming is not clearly recognized in the summer season. This simulated feature of elevation dependency of ground temperature is consistent with observations. Based on an analysis of surface energy budget, the short wave solar radiation absorbed at the surface plus downward long wave flux reaching the surface shows a strong elevation dependency, and is mostly responsible for enhanced surface warming over the TP. At lower elevations, the precipitation forced by topography is enhanced due to an increase in water vapor supply resulted from a warming in the atmosphere induced by doubling CO2. This precipitation enhancement must be associated with an increase in clouds, which results in a decline in solar flux reaching surface. At higher elevations, large snow depletion is detected in the 2xCO2run. It leads to a decrease in albedo, therefore more solar flux is absorbed at the surface. On the other hand, much more uniform increase in downward long wave flux reaching the surface is found. The combination of these effects (i.e. decrease in solar flux at lower elevations, increase in solar flux at higher elevation and more uniform increase in downward long wave flux) results in elevation dependency of enhanced ground temperature warming over the TP.

Chen, Baode; Chao, Winston C.; Liu, Xiao-Dong; Lau, William K. M. (Technical Monitor)

2001-01-01

274

Warm-water decapods and the trophic amplification of climate in the North Sea.  

PubMed

A long-term time series of plankton and benthic records in the North Sea indicates an increase in decapods and a decline in their prey species that include bivalves and flatfish recruits. Here, we show that in the southern North Sea the proportion of decapods to bivalves doubled following a temperature-driven, abrupt ecosystem shift during the 1980s. Analysis of decapod larvae in the plankton reveals a greater presence and spatial extent of warm-water species where the increase in decapods is greatest. These changes paralleled the arrival of new species such as the warm-water swimming crab Polybius henslowii now found in the southern North Sea. We suggest that climate-induced changes among North Sea decapods have played an important role in the trophic amplification of a climate signal and in the development of the new North Sea dynamic regime. PMID:20554562

Lindley, J A; Beaugrand, G; Luczak, C; Dewarumez, J-M; Kirby, R R

2010-12-23

275

Warm-water decapods and the trophic amplification of climate in the North Sea  

PubMed Central

A long-term time series of plankton and benthic records in the North Sea indicates an increase in decapods and a decline in their prey species that include bivalves and flatfish recruits. Here, we show that in the southern North Sea the proportion of decapods to bivalves doubled following a temperature-driven, abrupt ecosystem shift during the 1980s. Analysis of decapod larvae in the plankton reveals a greater presence and spatial extent of warm-water species where the increase in decapods is greatest. These changes paralleled the arrival of new species such as the warm-water swimming crab Polybius henslowii now found in the southern North Sea. We suggest that climate-induced changes among North Sea decapods have played an important role in the trophic amplification of a climate signal and in the development of the new North Sea dynamic regime. PMID:20554562

Lindley, J. A.; Beaugrand, G.; Luczak, C.; Dewarumez, J.-M.; Kirby, R. R.

2010-01-01

276

Warming climate extends dryness-controlled areas of terrestrial carbon sequestration  

NASA Astrophysics Data System (ADS)

At biome-scale, terrestrial carbon uptake is controlled mainly by weather variability. Observational data from a global monitoring network indicate that the sensitivity of terrestrial carbon sequestration to mean annual temperature (T) breaks down at a threshold value of 16°C, above which terrestrial CO2 fluxes are controlled by dryness rather than temperature. Here we show that since 1948 warming climate has moved the 16°C T latitudinal belt poleward. Land surface area with T > 16°C and now subject to dryness control rather than temperature as the regulator of carbon uptake has increased by 6% and is expected to increase by at least another 8% by 2050. Most of the land area subjected to this warming is arid or semiarid with ecosystems that are highly vulnerable to drought and land degradation. In areas now dryness-controlled, net carbon uptake is ~27% lower than in areas in which both temperature and dryness (T < 16°C) regulate plant productivity. This warming-induced extension of dryness-controlled areas may be triggering a positive feedback accelerating global warming. Continued increases in land area with T > 16°C has implications not only for positive feedback on climate change, but also for ecosystem integrity and land cover, particularly for pastoral populations in marginal lands.

Yi, Chuixiang; Wei, Suhua; Hendrey, George

2014-07-01

277

Warming climate extends dryness-controlled areas of terrestrial carbon sequestration  

PubMed Central

At biome-scale, terrestrial carbon uptake is controlled mainly by weather variability. Observational data from a global monitoring network indicate that the sensitivity of terrestrial carbon sequestration to mean annual temperature (T) breaks down at a threshold value of 16°C, above which terrestrial CO2 fluxes are controlled by dryness rather than temperature. Here we show that since 1948 warming climate has moved the 16°C T latitudinal belt poleward. Land surface area with T > 16°C and now subject to dryness control rather than temperature as the regulator of carbon uptake has increased by 6% and is expected to increase by at least another 8% by 2050. Most of the land area subjected to this warming is arid or semiarid with ecosystems that are highly vulnerable to drought and land degradation. In areas now dryness-controlled, net carbon uptake is ~27% lower than in areas in which both temperature and dryness (T < 16°C) regulate plant productivity. This warming-induced extension of dryness-controlled areas may be triggering a positive feedback accelerating global warming. Continued increases in land area with T > 16°C has implications not only for positive feedback on climate change, but also for ecosystem integrity and land cover, particularly for pastoral populations in marginal lands. PMID:24980649

Yi, Chuixiang; Wei, Suhua; Hendrey, George

2014-01-01

278

Warming climate extends dryness-controlled areas of terrestrial carbon sequestration.  

PubMed

At biome-scale, terrestrial carbon uptake is controlled mainly by weather variability. Observational data from a global monitoring network indicate that the sensitivity of terrestrial carbon sequestration to mean annual temperature (T) breaks down at a threshold value of 16°C, above which terrestrial CO? fluxes are controlled by dryness rather than temperature. Here we show that since 1948 warming climate has moved the 16°C T latitudinal belt poleward. Land surface area with T > 16°C and now subject to dryness control rather than temperature as the regulator of carbon uptake has increased by 6% and is expected to increase by at least another 8% by 2050. Most of the land area subjected to this warming is arid or semiarid with ecosystems that are highly vulnerable to drought and land degradation. In areas now dryness-controlled, net carbon uptake is ~27% lower than in areas in which both temperature and dryness (T < 16°C) regulate plant productivity. This warming-induced extension of dryness-controlled areas may be triggering a positive feedback accelerating global warming. Continued increases in land area with T > 16°C has implications not only for positive feedback on climate change, but also for ecosystem integrity and land cover, particularly for pastoral populations in marginal lands. PMID:24980649

Yi, Chuixiang; Wei, Suhua; Hendrey, George

2014-01-01

279

Floodplains, permafrost, cottonwood trees, and peat: What happened the last time climate warmed suddenly in arctic Alaska?  

NASA Astrophysics Data System (ADS)

We use the stratigraphy of floodplains on Alaska's North Slope to describe how tundra watersheds responded to climate changes over the last 15,000 calibrated years BP (15 cal ka BP). Two episodes of extremely rapid floodplain alluviation occurred during the Pleistocene-Holocene transition, one between 14 and 12.8 cal ka BP and the other between 11.5 and 9.5 cal ka BP. These aggradation episodes coincided with periods of warming in summer when cottonwood ( Populus balsamifera L.) expanded its range, peatlands became established, and widespread thermokarst occurred. The two aggradation episodes were separated by a period of floodplain incision during the Younger Dryas under cooler and possibly drier conditions. At times of increasing summer warmth, melting permafrost and enhanced precipitation probably triggered widespread mass wasting on hillslopes that overwhelmed the capacity of streams to transport sediment downstream, and rapid floodplain aggradation resulted. After peatlands became widespread in the early Holocene, rivers slowly incised their valley fills. Because major pulses of sediment input were limited to times of rapid thaw and increasing moisture, many floodplains on the North Slope have been effectively decoupled from upstream hillslopes for much of the past 15,000 years. Our findings: (a) confirm the sensitivity of arctic watersheds to rapid warming in summer, (b) emphasize the importance of hillslope mass wasting in landscape-scale responses to climate change, and (c) suggest that the presence of peatland on this arctic landscape today has raised its geomorphic response threshold to climate warming compared to what it was 14,000 years ago.

Mann, Daniel H.; Groves, Pamela; Reanier, Richard E.; Kunz, Michael L.

2010-12-01

280

The ice-core record - Climate sensitivity and future greenhouse warming  

NASA Technical Reports Server (NTRS)

The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

1990-01-01

281

Students’ conceptions about the greenhouse effect, global warming, and climate change  

Microsoft Academic Search

The purpose of this study was to investigate students’ conceptions of the greenhouse effect, global warming, and climate change.\\u000a The study was descriptive in nature and reflected a cross-age design involving the collection of qualitative data from 51\\u000a secondary students from three different schools in the Midwest, USA. These data were analyzed for content in an inductive\\u000a manner to identify

Daniel P. Shepardson; Dev Niyogi; Soyoung Choi; Umarporn Charusombat

2011-01-01

282

Climatic changes and associated impacts in the Mediterranean resulting from a 2 °C global warming  

Microsoft Academic Search

Climatic changes over the Mediterranean basin in 2031–2060, when a 2 °C global warming is most likely to occur, are investigated with the HadCM3 global circulation model and their impacts on human activities and natural ecosystem are assessed. Precipitation and surface temperature changes are examined through mean and extreme values analysis, under the A2 and B2 emission scenarios. Confidence in results

C. Giannakopoulos; P. Le Sager; M. Bindi; M. Moriondo; E. Kostopoulou; C. M. Goodess

2009-01-01

283

Trace element determination in warm-climate plants by Atomic Absorption Spectroscopy and Ion Selective Electrodes  

Microsoft Academic Search

Minor and trace elements of biological interest in some warm climate plants cultivated at Aswan (Egypt) were analysed to demonstrate their element metabolism, animal nutrition, toxicological effect and their uses as therapeutic plants. The seven plants studied wereMacroptilium atropurpureum,Pennisetum glaucum,Cyamopsis tetragonolobus,Dolichos purpureus,Cajanus cajan8 (Variety 78\\/237 A-Brasil),Cajanus cajan13 (Variety 79\\/450 Uganda) andProsopis juliflora. Silver, gold, cadmium, cobalt, copper, iron, potassium, manganese,

M. N. Rashed

1995-01-01

284

Coherent Transmission: A Technique for Stopping Global Warming and Climate Change  

Microsoft Academic Search

\\u000a “Green ICT” means Information and Communications Technology friendly for the globe. To stop global warming and climate change,\\u000a ICT, with low emission of carbon dioxide thus low consumption of energy, is required. When there was no constraint of low\\u000a energy consumption in communications, one solution for making us happier and more comfortable from the information-transmission\\u000a perspective was to have a

Shinsuke Hara

285

Climate warming increases Greenland Ice Sheet surface mass balance variability  

NASA Astrophysics Data System (ADS)

We analyze Greenland Ice Sheet (GIS) surface mass balance (SMB) trends generated by the Community Earth System Model for the time period 1850-2100. In addition to the expected decrease in the mean SMB, our analysis reveals a significant secular increase in temporal, integrated SMB variability. The largest variability increase occurs during the 21st century, and arises primarily from growth of the GIS ablation zone (i.e., a decrease in the accumulation area ratio, AAR) in conjunction with a high ratio of ablation-zone to accumulation-zone specific SMB variability. A secondary cause of the overall variability increase is a rise in specific SMB variability itself in both the accumulation and ablation zones, due to increased accumulation variability and lengthened melt seasons. Simple sensitivity experiments indicate that neither mechanism (decrease in the AAR, and increased specific SMB variability) in isolation is capable of causing the overall increase in integrated SMB variability. However, by exposing more of the ice sheet to high-variability ablation, the decrease in the AAR is about twice as effective as increased specific SMB variability in causing the overall variability increase. Ablation-zone SMB variability is driven largely by variability in summertime melting which is in turn regulated by variability in summertime surface energy fluxes. Broader climate processes that regulate these fluxes will therefore exert increasing control on GIS SMB variability in the future. This future increase in SMB variability can be expected to impact GIS-sourced freshwater fluxes and GIS ice dynamic variability, and may also make it more difficult to diagnose future secular trends in GIS volume.

Fyke, J. G.; Vizcaino, M.; Lipscomb, W. H.; Sacks, W.

2013-12-01

286

500-year climate cycles stacking of recent centennial warming documented in an East Asian pollen record  

PubMed Central

Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus, and a temperature proxy, revealed ~500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ~500-year cyclic climate change occurred in EA during the mid-late Holocene and even the last 150 years dominated by anthropogenic forcing. It was almost in phase with a ~500-year periodic change in solar activity and Greenland temperature change, suggesting that ~500-year small variations in solar output played a prominent role in the mid-late Holocene climate dynamics in EA, linked to high latitude climate system. Its last warm phase might terminate in the next several decades to enter another ~250-year cool phase, and thus this future centennial cyclic temperature minimum could partially slow down man-made global warming. PMID:24402348

Xu, Deke; Lu, Houyuan; Chu, Guoqiang; Wu, Naiqin; Shen, Caiming; Wang, Can; Mao, Limi

2014-01-01

287

A global experiment suggests climate warming will not accelerate litter decomposition in streams but might reduce carbon sequestration.  

PubMed

The decomposition of plant litter is one of the most important ecosystem processes in the biosphere and is particularly sensitive to climate warming. Aquatic ecosystems are well suited to studying warming effects on decomposition because the otherwise confounding influence of moisture is constant. By using a latitudinal temperature gradient in an unprecedented global experiment in streams, we found that climate warming will likely hasten microbial litter decomposition and produce an equivalent decline in detritivore-mediated decomposition rates. As a result, overall decomposition rates should remain unchanged. Nevertheless, the process would be profoundly altered, because the shift in importance from detritivores to microbes in warm climates would likely increase CO(2) production and decrease the generation and sequestration of recalcitrant organic particles. In view of recent estimates showing that inland waters are a significant component of the global carbon cycle, this implies consequences for global biogeochemistry and a possible positive climate feedback. PMID:21299824

Boyero, Luz; Pearson, Richard G; Gessner, Mark O; Barmuta, Leon A; Ferreira, Verónica; Graça, Manuel A S; Dudgeon, David; Boulton, Andrew J; Callisto, Marcos; Chauvet, Eric; Helson, Julie E; Bruder, Andreas; Albariño, Ricardo J; Yule, Catherine M; Arunachalam, Muthukumarasamy; Davies, Judy N; Figueroa, Ricardo; Flecker, Alexander S; Ramírez, Alonso; Death, Russell G; Iwata, Tomoya; Mathooko, Jude M; Mathuriau, Catherine; Gonçalves, José F; Moretti, Marcelo S; Jinggut, Tajang; Lamothe, Sylvain; M'Erimba, Charles; Ratnarajah, Lavenia; Schindler, Markus H; Castela, José; Buria, Leonardo M; Cornejo, Aydeé; Villanueva, Verónica D; West, Derek C

2011-03-01

288

Ocean Heat Transport and Water Vapor Greenhouse in a Warm Equable Climate: A New Look at the Low Gradient Paradox  

E-print Network

The authors study the role of ocean heat transport (OHT) in the maintenance of a warm, equable, ice-free climate. An ensemble of idealized aquaplanet GCM calculations is used to assess the equilibrium sensitivity of global ...

Rose, Brian E. J.

289

Ocean surface warming: The North Atlantic remains within the envelope of previous recorded conditions  

NASA Astrophysics Data System (ADS)

Anomalously warm air temperatures in various parts of the world have been widely noted in recent decades. In marine systems, biological indicators such as the range of plankton and fish have been used to indicate impacts of ocean warming, although for many regions recent ocean warming does not exceed short-term warming events over the last two centuries. Here we use International Comprehensive Ocean-Atmosphere Data Set (ICOADS) sea-surface temperature data to update analysis in the North Atlantic to show that present warm conditions are currently no more persistent than those encountered in the last 150 years. We show that the position of various isotherms, which play a central role in influencing the distribution of marine taxa ranging from plankton to fish and turtles, are more regularly found further north in recent years than at any time since the 1850s.

Hobson, Victoria J.; McMahon, Clive R.; Richardson, Anthony; Hays, Graeme C.

2008-02-01

290

Formability analysis of austenitic stainless steel-304 under warm conditions  

NASA Astrophysics Data System (ADS)

A warm deep drawing process of austenitic stainless steel-304 (ASS-304) of circular blanks with coupled ther mal analysis is studied in this article. 65 mm blanks were deep drawn at different temperatures and thickness distribution is experimentally measured after cutting the drawn component into two halves. The process is simulated using explicit fin ite element code LS-DYNA. A Barlat 3 parameter model is used in the simulation, as the material is anisotropic up to 30 0°C. Material properties for the simulation are determined at different temperatures using a 5 T UTM coupled with a furn ace. In this analysis constant punch speed and variable blank holder force (BHF) is applied to draw cups without wrinkle.

Lade, Jayahari; Singh, Swadesh Kumar; Banoth, Balu Naik; Gupta, Amit Kumar

2013-12-01

291

Soil Warming Alters the Nitrogen Cycle: Ecosystem Implications and Feedbacks to the Climate System  

NASA Astrophysics Data System (ADS)

Increases in soil temperatures associated with global warming have the potential to accelerate nitrogen turnover in soils, which could alter other biogeochemical processes and eventually affect the structure of these forests. Over the past five years we have been studying soil and plant responses to soil warming in large plots in a deciduous stand at Harvard Forest in central Massachusetts. We have heated the soil 5°C above ambient and measured nitrogen cycling parameters including in situ net nitrogen mineralization and nitrification, nitrogen leaching and nitrous oxide (N2O) fluxes. We have also measured various aspects of the carbon cycle including soil respiration and carbon accumulation in vegetation. Over the first five years of the study, we observed a mean annual increase in the net nitrogen mineralized in the warmed plot of 23.8 kg N ha-1. While nitrification rates were low throughout the five years in the control plot, they increased in the warmed plot to account for over 25% of the total net nitrogen mineralized in year five. The increase in nitrogen mineralization stimulated tree growth and carbon storage in woody tissue in the warmed plot. The increased carbon storage in the trees compensated for more than half of the carbon lost from the soils due to accelerated decay of soil organic matter and so reduced the magnitude of the positive feedback to the climate system due to soil warming. We hypothesize that the increase in nitrification we observed will eventually "open" the nitrogen cycle and make gaseous and solution losses more likely. To date, however, we have measured no major losses of nitrous oxide or solution losses of nitrate in response to soil warming. Trees with the capacity to use nitrate may have a competitive advantage in a warmer world. Nitrate-using plants have an inducible enzyme that transforms nitrate to ammonium, a key building block for producing essential amino acids and proteins. Studies by our research group and by others have shown that red maples (Acer rubrum), when grown with high levels of nitrate, have a greater ability to produce this enzyme than many other species common to the region's forests. We have also observed that red maple seedlings and saplings show a higher growth response to soil warming than juvenile plants of other species. Our working hypothesis is that some of this response is linked to the capacity of red maple to use the nitrate produced in the warmed soils. In the long term, warming could lead to red maples becoming a more dominant tree in the forests of southern New England.

Butler, S. M.; Melillo, J. M.; Johnson, J. E.; Mohan, J. E.; Steudler, P. A.; Bowles, F. P.

2008-12-01

292

Cloud feedbacks on greenhouse warming in the superparameterized climate model SP-CCSM4  

NASA Astrophysics Data System (ADS)

Cloud feedbacks on greenhouse warming are studied in a superparameterized version of the Community Climate System Model (SP-CCSM4) in an atmospheric component SP-CAM4 that explicitly simulates cumulus convection. A 150 year simulation in an abrupt quadrupling of CO2 is branched from a control run. It develops moderate positive global cloud feedback and an implied climate sensitivity of 2.8 K comparable to the conventionally parameterized CCSM4 and the median of other modern climate models. All of SP-CCSM4's positive shortwave cloud feedback is due to a striking decrease in low cloud over land, which is much more pronounced than in most other climate models, including CCSM4. Four other cloud responses - decreased midlevel cloud, more Arctic water and ice cloud, a slight poleward shift of midlatitude storm track cloud, and an upward shift of high clouds - are also typical of conventional global climate models. SP-CCSM4 does not simulate the large warming-induced decrease in Southern Ocean cloud found in CCSM4. Two companion uncoupled SP-CAM4 simulations, one with a uniform 4 K sea-surface temperature increase and one with quadrupled CO2 but fixed SST, suggest that SP-CCSM4's global-scale cloud changes are primarily mediated by the warming, rather than by rapid adjustments to increased CO2. SP-CAM4 show spatial patterns of cloud response qualitatively similar to the previous-generation superparameterized SP-CAM3, but with systematically more positive low cloud feedbacks over low-latitude land and ocean.

Bretherton, Christopher S.; Blossey, Peter N.; Stan, Cristiana

2014-12-01

293

Heat-Related Mortality in a Warming Climate: Projections for 12 U.S. Cities  

PubMed Central

Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience. PMID:25365060

Petkova, Elisaveta P.; Bader, Daniel A.; Anderson, G. Brooke; Horton, Radley M.; Knowlton, Kim; Kinney, Patrick L.

2014-01-01

294

Heat-related mortality in a warming climate: projections for 12 U.S. cities.  

PubMed

Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience. PMID:25365060

Petkova, Elisaveta P; Bader, Daniel A; Anderson, G Brooke; Horton, Radley M; Knowlton, Kim; Kinney, Patrick L

2014-11-01

295

Plant responses to elevated temperatures: a field study on phenological sensitivity and fitness responses to simulated climate warming  

PubMed Central

Significant changes in plant phenology have been observed in response to increases in mean global temperatures. There are concerns that accelerated phenologies can negatively impact plant populations. However, the fitness consequence of changes in phenology in response to elevated temperature is not well understood, particularly under field conditions. We address this issue by exposing a set of recombinant inbred lines of Arabidopsis thaliana to a simulated global warming treatment in the field. We find that plants exposed to elevated temperatures flower earlier, as predicted by photothermal models. However, contrary to life-history trade-off expectations, they also flower at a larger vegetative size, suggesting that warming probably causes acceleration in vegetative development. Although warming increases mean fitness (fruit production) by ca. 25%, there is a significant genotype-by-environment interaction. Changes in fitness rank indicate that imminent climate change can cause populations to be maladapted in their new environment, if adaptive evolution is limited. Thus, changes in the genetic composition of populations are likely, depending on the species’ generation time and the speed of temperature change. Interestingly, genotypes that show stronger phenological responses have higher fitness under elevated temperatures, suggesting that phenological sensitivity might be a good indicator of success under elevated temperature at the genotypic level as well as at the species level. PMID:24130095

Springate, David A; Kover, Paula X

2014-01-01

296

Plant responses to elevated temperatures: a field study on phenological sensitivity and fitness responses to simulated climate warming.  

PubMed

Significant changes in plant phenology have been observed in response to increases in mean global temperatures. There are concerns that accelerated phenologies can negatively impact plant populations. However, the fitness consequence of changes in phenology in response to elevated temperature is not well understood, particularly under field conditions. We address this issue by exposing a set of recombinant inbred lines of Arabidopsis thaliana to a simulated global warming treatment in the field. We find that plants exposed to elevated temperatures flower earlier, as predicted by photothermal models. However, contrary to life-history trade-off expectations, they also flower at a larger vegetative size, suggesting that warming probably causes acceleration in vegetative development. Although warming increases mean fitness (fruit production) by ca. 25%, there is a significant genotype-by-environment interaction. Changes in fitness rank indicate that imminent climate change can cause populations to be maladapted in their new environment, if adaptive evolution is limited. Thus, changes in the genetic composition of populations are likely, depending on the species' generation time and the speed of temperature change. Interestingly, genotypes that show stronger phenological responses have higher fitness under elevated temperatures, suggesting that phenological sensitivity might be a good indicator of success under elevated temperature at the genotypic level as well as at the species level. PMID:24130095

Springate, David A; Kover, Paula X

2014-02-01

297

Changing habitat associations of a thermally constrained species, the silver-spotted skipper butterfly, in response to climate warming.  

PubMed

1. The impact of climate change on the distribution, abundance, phenology and ecophysiology of species is already well documented, whereas the influence of climate change on habitat choice and utilization has received little attention. Here we report the changing habitat associations of a thermally constrained grassland butterfly, Hesperia comma, over 20 years. 2. Between 1982 and 2001-2, the optimum percentage of bare ground within habitat used for egg-laying shifted from 41% to 21%. 3. Egg-laying rates are temperature-dependent and females actively adjust microhabitat usage in response to temperature variations; relatively warmer host plants are chosen or oviposition at low ambient temperatures, and cooler host plants at high ambient temperatures. 4. Climate warming has increased the availability of thermally suitable habitat for H. comma at the cool, northern edge of the species' distribution, therefore increasing: (a) egg-laying rate and potentially the realized rate of population increase; (b) effective area of habitat patches as more microhabitats within a given vegetation fragment are now suitable for egg-laying; (c) buffering of populations against environmental variation as eggs are laid within a wider range of microhabitats; and (d) the number of habitat patches in the landscape that are currently available for colonization (including the use of more northerly facing aspects; Thomas et al., Nature, 2001, 411, 577-581). 5. Conservationists often assume the habitat requirements of a species to be constant, and manage habitats to maintain these conditions. For many species, these requirements are likely to change in response to climate warming, and care must be taken not to manage habitats based on outdated prescriptions. PMID:16903062

Davies, Zoe G; Wilson, Robert J; Coles, Sophie; Thomas, Chris D

2006-01-01

298

Warm climates of the past--a lesson for the future?  

PubMed

This Discussion Meeting Issue of the Philosophical Transactions A had its genesis in a Discussion Meeting of the Royal Society which took place on 10-11 October 2011. The Discussion Meeting, entitled 'Warm climates of the past: a lesson for the future?', brought together 16 eminent international speakers from the field of palaeoclimate, and was attended by over 280 scientists and members of the public. Many of the speakers have contributed to the papers compiled in this Discussion Meeting Issue. The papers summarize the talks at the meeting, and present further or related work. This Discussion Meeting Issue asks to what extent information gleaned from the study of past climates can aid our understanding of future climate change. Climate change is currently an issue at the forefront of environmental science, and also has important sociological and political implications. Most future predictions are carried out by complex numerical models; however, these models cannot be rigorously tested for scenarios outside of the modern, without making use of past climate data. Furthermore, past climate data can inform our understanding of how the Earth system operates, and can provide important contextual information related to environmental change. All past time periods can be useful in this context; here, we focus on past climates that were warmer than the modern climate, as these are likely to be the most similar to the future. This introductory paper is not meant as a comprehensive overview of all work in this field. Instead, it gives an introduction to the important issues therein, using the papers in this Discussion Meeting Issue, and other works from all the Discussion Meeting speakers, as exemplars of the various ways in which past climates can inform projections of future climate. Furthermore, we present new work that uses a palaeo constraint to quantitatively inform projections of future equilibrium ice sheet change. PMID:24043873

Lunt, D J; Elderfield, H; Pancost, R; Ridgwell, A; Foster, G L; Haywood, A; Kiehl, J; Sagoo, N; Shields, C; Stone, E J; Valdes, P

2013-10-28

299

Change in abundance of pacific brant wintering in alaska: evidence of a climate warming effect?  

USGS Publications Warehouse

Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from lowtemperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of the wintering populations. Mean surface air temperatures during winter at the end of the Alaska Peninsula increased about 1??C between 1963 and 2004, resulting in a 23% reduction in freezing degree days and a 34% decline in the number of days when ice cover prevents birds from accessing food resources. Trends in the wintering population fluctuated with states of the Pacific Decadal Oscillation, increasing during positive (warm) phases and decreasing during negative (cold) phases, and this correlation provides support for the hypothesis that growth in the wintering population of brant in Alaska is linked to climate warming. The size of the wintering population was negatively correlated with the number of days of strong northwesterly winds in November, which suggests that the occurrence of tailwinds favorable for migration before the onset of winter was a key factor in whether brant migrated from Alaska or remained there during winter. Winter distribution of brant on the Alaska Peninsula was highly variable and influenced by ice cover, particularly at the heavily used Izembek Lagoon. Observations of previously marked brant indicated that the Alaska wintering population was composed primarily of birds originating from Arctic breeding colonies that appear to be growing. Numbers of brant in Alaska during winter will likely increase as temperatures rise and ice cover decreases at high latitudes in response to climate warming. ?? The Arctic Institute of North America.

Ward, D.H.; Dau, C.P.; Lee, T.; Sedinger, J.S.; Anderson, B.A.; Hines, J.E.

2009-01-01

300

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America.  

PubMed

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period - a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI - high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to climate warming than the more diverse mixed forest catchments. PMID:24757012

Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

2014-10-01

301

Changing forest water yields in response to climate warming: results from long-term experimental watershed sites across North America  

PubMed Central

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment's change in actual ET divided by P [AET/P; evaporative index (EI)] coincident with a shift from a cool to a warm period – a positive d indicates an upward shift in EI and smaller than expected water yields, and a negative d indicates a downward shift in EI and larger than expected water yields. Elasticity was defined as the ratio of interannual variation in potential ET divided by P (PET/P; dryness index) to interannual variation in the EI – high elasticity indicates low d despite large range in drying index (i.e., resilient water yields), low elasticity indicates high d despite small range in drying index (i.e., nonresilient water yields). Although the data needed to fully evaluate ecosystems based on these metrics are limited, we were able to identify some characteristics of response among forest types. Alpine sites showed the greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer forests included catchments with lowest elasticity and stable to larger water yields. Deciduous forests included catchments with intermediate elasticity and stable to smaller water yields. Mixed coniferous/deciduous forests included catchments with highest elasticity and stable water yields. Forest type appeared to influence the resilience of catchment water yields to climate warming, with conifer and deciduous catchments more susceptible to climate warming than the more diverse mixed forest catchments. PMID:24757012

Creed, Irena F; Spargo, Adam T; Jones, Julia A; Buttle, Jim M; Adams, Mary B; Beall, Fred D; Booth, Eric G; Campbell, John L; Clow, Dave; Elder, Kelly; Green, Mark B; Grimm, Nancy B; Miniat, Chelcy; Ramlal, Patricia; Saha, Amartya; Sebestyen, Stephen; Spittlehouse, Dave; Sterling, Shannon; Williams, Mark W; Winkler, Rita; Yao, Huaxia

2014-01-01

302

Accounting for global-mean warming and scaling uncertainties in climate change impact studies Hydrol. Earth Syst. Sci., 11(3), 12071226, 2007  

E-print Network

Accounting for global-mean warming and scaling uncertainties in climate change impact studies 1207(s) 2007. This work is licensed under a Creative Commons License. Accounting for global-mean warming from a few regional climate model runs are scaled, based on different global-mean warming projections

Paris-Sud XI, Université de

303

Probability distributions for regional climate change from uncertain global mean warming and uncertain scaling relationship Hydrol. Earth Syst. Sci., 11(3), 10971114, 2007  

E-print Network

Probability distributions for regional climate change from uncertain global mean warming of probability distributions for regional climate change from uncertain global mean warming and an uncertain/precipitation per degree global mean warming. Each scaling variable is assumed to be normally distributed

Paris-Sud XI, Université de

304

Winter 2010 in Europe: A cold extreme in a warming climate  

NASA Astrophysics Data System (ADS)

The winter of 2009/2010 was characterized by record persistence of the negative phase of the North-Atlantic Oscillation (NAO) which caused several severe cold spells over Northern and Western Europe. This somehow unusual winter with respect to the most recent ones arose concurrently with public debate on climate change, during and after the Copenhagen climate negotiations. We show however that the cold European temperature anomaly of winter 2010 was (i) not extreme relative to winters of the past six decades, and (ii) warmer than expected from its record-breaking seasonal circulation indices such as NAO or blocking frequency. Daily flow-analogues of winter 2010, taken in past winters, were associated with much colder temperatures. The winter 2010 thus provides a consistent picture of a regional cold event mitigated by long-term climate warming.

Cattiaux, J.; Vautard, R.; Cassou, C.; Yiou, P.; Masson-Delmotte, V.; Codron, F.

2010-10-01

305

Earlier wine-grape ripening driven by climatic warming and drying and management practices  

NASA Astrophysics Data System (ADS)

Trends in phenological phases associated with climate change are widely reported--yet attribution remains rare. Attribution research in biological systems is critical in assisting stakeholders to develop adaptation strategies, particularly if human factors may be exacerbating impacts. Detailed, quantified attribution helps to effectively target adaptation strategies, and counters recent tendencies to overattribute phenological trends to climate shifts. Wine grapes have been ripening earlier in Australia in recent years, often with undesirable impacts. Attribution analysis of detected trends in wine-grape maturity, using time series of up to 64 years in duration, indicates that two climate variables--warming and declines in soil water content--are driving a major portion of this ripening trend. Crop-yield reductions and evolving management practices have probably also contributed to earlier ripening. Potential adaptation options are identified, as some drivers of the trend to earlier maturity can be manipulated through directed management initiatives, such as managing soil moisture and crop yield.

Webb, L. B.; Whetton, P. H.; Bhend, J.; Darbyshire, R.; Briggs, P. R.; Barlow, E. W. R.

2012-04-01

306

Tittel: An Alternative to the Global Warming Potential for Comparing Climate Impacts of Emissions of Greenhouse Gases Title: An Alternative to the Global Warming Potential for Comparing Climate Impacts of Emissions of Greenhouse Gases  

Microsoft Academic Search

The Global Warming Potential (GWP) is used within the Kyoto Protocol to the United Nations Framework Convention on Climate Change as a metric for weighting the climatic impact of emissions of different greenhouse gases. The GWP has been subject to many criticisms because of its formulation, but nevertheless it has retained some favour because of the simplicity of its design

Keith P. Shine; Jan S. Fuglestvedt; Nicola Stuber

307

Sensitivity of spring phenology to warming across temporal and spatial climate gradients in two independent databases  

NASA Astrophysics Data System (ADS)

Disparate ecological datasets are often organized into databases post-hoc and then analyzed and interpreted in ways that may diverge from the purposes of the original data collections. Few studies, however, have attempted to quantify how biases inherent in these data (e.g., species richness, replication, climate) affect their suitability for addressing broad scientific questions, especially in under-represented systems (e.g., deserts, tropical forests) and wild communities. Here, we quantitatively compare the sensitivity of species first flowering and leafing dates to spring warmth in two phenological databases from the Northern Hemisphere. One—PEP725—has high replication within and across sites, but has low species diversity and spans a limited climate gradient. The other—NECTAR—includes many more species and a wider range of climates, but has fewer sites and low replication of species across sites. PEP725, despite low species diversity and relatively low seasonality, accurately captures the magnitude and seasonality of warming responses at climatically similar NECTAR sites, with most species showing earlier phenological events in response to warming. In NECTAR, the prevalence of temperature responders significantly declines with increasing mean annual temperature, a pattern that cannot be detected across the limited climate gradient spanned by the PEP725 flowering and leafing data. Our results showcase broad areas of agreement between the two databases, despite significant differences in species richness and geographic coverage, while also noting areas where including data across broader climate gradients may provide added value. Such comparisons help to identify gaps in our observations and knowledge base that can be addressed by ongoing monitoring and research efforts. Resolving these issues will be critical for improving predictions in understudied and undersampled systems outside of the temperature seasonal midlatitudes.

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

2012-12-01

308

The intrinsic growth rate as a predictor of population viability under climate warming.  

PubMed

1. Lately, there has been interest in using the intrinsic growth rate (rm) to predict the effects of climate warming on ectotherm population viability. However, because rm is calculated using the Euler-Lotka equation, its reliability in predicting population persistence depends on whether ectotherm populations can achieve a stable age/stage distribution in thermally variable environments. Here, we investigate this issue using a mathematical framework that incorporates mechanistic descriptions of temperature effects on vital rates into a stage-structured population model that realistically captures the temperature-induced variability in developmental delays that characterize ectotherm life cycles. 2. We find that populations experiencing seasonal temperature variation converge to a stage distribution whose intra-annual pattern remains invariant across years. As a result, the mean annual per capita growth rate also remains constant between years. The key insight is the mechanism that allows populations converge to a stationary stage distribution. Temperature effects on the biochemical processes (e.g. enzyme kinetics, hormonal regulation) that underlie life-history traits (reproduction, development and mortality) exhibit well-defined thermodynamical properties (e.g. changes in entropy and enthalpy) that lead to predictable outcomes (e.g. reduction in reaction rates or hormonal action at temperature extremes). As a result, life-history traits exhibit a systematic and predictable response to seasonal temperature variation. This in turn leads to temporally predictable temperature responses of the stage distribution and the per capita growth rate. 3. When climate warming causes an increase in the mean annual temperature and/or the amplitude of seasonal fluctuations, the population model predicts the mean annual per capita growth rate to decline to zero within 100 years when warming is slow relative to the developmental period of the organism (0.03-0.05°C per year) and to become negative, causing population extinction, well before 100 years when warming is fast (e.g. 0.1°C per year). The Euler-Lotka equation predicts a slower decrease in rm when warming is slow and a longer persistence time when warming is fast, with the deviation between the two metrics increasing with increasing developmental period. These results suggest that predictions of ectotherm population viability based on rm may be valid only for species with short developmental delays, and even then, only over short time-scales and under slow warming regimes. PMID:23926903

Amarasekare, Priyanga; Coutinho, Renato M

2013-11-01

309

Supraglacial lakes on the Greenland ice sheet advance inland under warming climate  

NASA Astrophysics Data System (ADS)

Supraglacial lakes (SGLs) form annually on the Greenland ice sheet and, when they drain, their discharge enhances ice-sheet flow by lubricating the base and potentially by warming the ice. Today, SGLs tend to form within the ablation zone, where enhanced lubrication is offset by efficient subglacial drainage. However, it is not clear what impact a warming climate will have on this arrangement. Here, we use an SGL initiation and growth model to show that lakes form at higher altitudes as temperatures rise, consistent with satellite observations. Our simulations show that in southwest Greenland, SGLs spread 103 and 110 km further inland by the year 2060 under moderate (RCP 4.5) and extreme (RCP 8.5) climate change scenarios, respectively, leading to an estimated 48-53% increase in the area over which they are distributed across the ice sheet as a whole. Up to half of these new lakes may be large enough to drain, potentially delivering water and heat to the ice-sheet base in regions where subglacial drainage is inefficient. In such places, ice flow responds positively to increases in surface water delivered to the bed through enhanced basal lubrication and warming of the ice, and so the inland advance of SGLs should be considered in projections of ice-sheet change.

Leeson, A. A.; Shepherd, A.; Briggs, K.; Howat, I.; Fettweis, X.; Morlighem, M.; Rignot, E.

2015-01-01

310

Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model.  

PubMed

The continued increase in the atmospheric concentration of carbon dioxide due to anthropogenic emissions is predicted to lead to significant changes in climate. About half of the current emissions are being absorbed by the ocean and by land ecosystems, but this absorption is sensitive to climate as well as to atmospheric carbon dioxide concentrations, creating a feedback loop. General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon-cycle models that do not include climate change. Here we present results from a fully coupled, three-dimensional carbon-climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century. We find that under a 'business as usual' scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, the ocean uptake rate of 5 Gt C yr(-1) is balanced by the terrestrial carbon source, and atmospheric CO2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models, resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback. PMID:11089968

Cox, P M; Betts, R A; Jones, C D; Spall, S A; Totterdell, I J

2000-11-01

311

A geohydrologic framework for characterizing summer streamflow sensitivity to climate warming in the Pacific Northwest, USA  

NASA Astrophysics Data System (ADS)

Summer streamflows in the Pacific Northwest are largely derived from melting snow and groundwater discharge. As the climate warms, diminishing snowpack and earlier snowmelt will cause reductions in summer streamflow. Most assessments of the impacts of a changing climate to streamflow make use of downscaled temperature and precipitation projections from General Circulation Models (GCMs). Projected climate simulations from these GCMs are often too coarse for planning purposes, as they do not capture smaller scale topographic controls and other important watershed processes. This uncertainty is further amplified when downscaled climate predictions are coupled to macroscale hydrologic models that fail to capture streamflow contributions from deep groundwater. Deep aquifers play an important role in mediating streamflow response to climate change, and groundwater needs to be explicitly incorporated into sensitivity assessments. Here we develop and apply an analytical framework for characterizing summer streamflow sensitivity to a change in the timing and magnitude of recharge in a spatially-explicit fashion. Two patterns emerge from this analysis: first, areas with high streamflow sensitivity also have higher summer streamflows as compared to low sensitivity areas. Second, the level of sensitivity and spatial extent of highly sensitive areas diminishes over time as the summer progresses. Results of this analysis point to a robust, practical, and scalable approach that can help assess risk at the landscape scale, complement the downscaling approach, be applied to any climate scenario of interest, and provide a framework to assist land and water managers adapt to an uncertain and potentially challenging future.

Safeeq, M.; Grant, G. E.; Lewis, S. L.; Kramer, M. G.; Staab, B.

2014-03-01

312

Reproductive and physiological responses to simulated climate warming for four subalpine species.  

PubMed

* The carbon costs of reproduction were examined in four subalpine herbaceous plant species for which number and size of flowers respond differently under a long-term infrared warming experiment. * Instantaneous measurements of gas exchange and an integrative model were used to calculate whole-plant carbon budgets and reproductive effort (RE). * Of the two species for which flowering was reduced, only one (Delphinium nuttallianum) exhibited higher RE under warming. The other species (Erythronium grandiflorum) flowers earlier when freezing events under warming treatment could have damaged floral buds. Of the two species for which flowering rates were not reduced, one (Helianthella quinquenervis) had higher RE, while RE was unaffected for the other (Erigeron speciosus). Each of these different responses was the result of a different combination of changes in organ size and physiological rates in each of the species. * Results show that the magnitude and direction of responses to warming differ greatly among species. Such results demonstrate the importance of examining multiple species to understand the complex interactions among physiological and reproductive responses to climate change. PMID:17176399

Lambrecht, Susan C; Loik, Michael E; Inouye, David W; Harte, John

2007-01-01

313

Modeling the subsurface thermal impact of Arctic thaw lakes in a warming climate  

NASA Astrophysics Data System (ADS)

Warming air temperatures in the Arctic are modifying the rates of thermokarst processes along Alaska's Arctic Coastal Plain. The Arctic Coastal Plain is dominated by thaw lakes. These kilometer-scale lakes are the most visible surface features in the region, and they provide important habitats for migratory birds. The lakes are formed by thermokarst processes, and are therefore susceptible to change as warming continues. We present a 1D numerical model of permafrost and subsidence processes in order to investigate the subsurface thermal impact of thaw lakes of various depths, and to evaluate how this impact might change in a warming climate. Currently, most thaw lakes in the region are shallow (<˜2 m deep), freeze to their base each winter, and are not underlain by permanently unfrozen ground (taliks). Field observations indicate that these shallow lakes have not greatly altered the thermal structure of the subsurface. Our model suggests that under a warming scenario, the number of lakes that do not freeze to their base during the winter, and are therefore underlain by taliks, will increase. Such changes could substantially alter the hydrology of the Arctic Coastal Plain.

Matell, N.; Anderson, R. S.; Overeem, I.; Wobus, C.; Urban, F. E.; Clow, G. D.

2013-04-01

314

Assessing the combined effect of dams and climate warming on streamflow in California's Sierra Nevada for regional-scale adaptation  

NASA Astrophysics Data System (ADS)

Dams and their operations harm river ecosystems, in part by altering the natural flow regimes that those ecosystems depend on. In the multi-reservoir water management systems of California's Sierra Nevada, greater emphasis is being placed on re-operating existing reservoir systems to recover downstream ecosystems. However, climate change is changing inflow patterns, affecting both ecosystems and traditional water system benefits across the region. As new reservoir operation schemes will be needed to manage for natural resources management objectives at the regional scale, characterizing historical and future environmental impacts of current operations across the region can aid in prioritizing planning efforts. We used a coarse-scale water resources simulation model developed for the western Sierra Nevada to explore the independent and combined effects of dams and climate warming on the flow regime directly below reservoirs, the focal point for instream flow requirements in operations licenses. We quantified changes to mean annual flow, annual low flow duration, annual runoff centroid timing, and weekly rate of decrease under binary combinations of management (unregulated/regulated) and climate (historical/future) conditions. We demonstrate that although rivers in the Sierra Nevada are currently managed in ways that are harmful to instream ecosystems, and that streamflow effects of operations are typically much worse than climate change effects, there are signals that reservoirs can potentially be used to help adapt to some of climate changes harmful effects with little additional effort in some cases. This study is the first step toward a better understanding of the environmental costs from and opportunities afforded by the current stock of reservoirs in a large hydroregion under changing social and environmental conditions.

Rheinheimer, D. E.; Viers, J. H.

2012-12-01

315

Enhancing Primary School Students' Knowledge about Global Warming and Environmental Attitude Using Climate Change Activities  

ERIC Educational Resources Information Center

Climate change generally and global warming specifically have become a common feature of the daily news. Due to widespread recognition of the adverse consequences of climate change on human lives, concerted societal effort has been taken to address it (e.g. by means of the science curriculum). This study was designed to test the effect that…

Karpudewan, Mageswary; Roth, Wolff-Michael; Bin Abdullah, Mohd Nor Syahrir

2015-01-01

316

The effect of global warming and global cooling on the distribution of the latest Permian climate zones  

Microsoft Academic Search

The end-Permian biotic crisis is commonly associated with rapid and severe climatic changes. These climatic changes are commonly suggested to have originated from solid Earth carbon degassing (leading to global warming), but aerosol- and ash-induced cooling induced by lava degassing has been suggested as well. The application of an Earth System Model of Intermediate Complexity has enabled a visualisation of

Marco Roscher; Frode Stordal; Henrik Svensen

2011-01-01

317

The cumulative effects of climate warming and other human stresses on Canadian freshwaters in the new millennium  

Microsoft Academic Search

Climate warming will adversely affect Canadian water quality and water quantity. The magnitude and timing of river flows and lake levels and water renewal times will change. In many regions, wetlands will disappear and water tables will decline. Habitats for cold stenothermic organisms will be reduced in small lakes. Warmer temperatures will affect fish migrations in some regions. Climate will

D. W. Schindler

2001-01-01

318

Thermal thresholds as predictors of seed dormancy release and germination timing: altitude-related risks from climate warming for the wild grapevine Vitis vinifera subsp. sylvestris  

PubMed Central

Background and Aims The importance of thermal thresholds for predicting seed dormancy release and germination timing under the present climate conditions and simulated climate change scenarios was investigated. In particular, Vitis vinifera subsp. sylvestris was investigated in four Sardinian populations over the full altitudinal range of the species (from approx. 100 to 800 m a.s.l). Methods Dried and fresh seeds from each population were incubated in the light at a range of temperatures (10–25 and 25/10 °C), without any pre-treatment and after a warm (3 months at 25 °C) or a cold (3 months at 5 °C) stratification. A thermal time approach was then applied to the germination results for dried seeds and the seed responses were modelled according to the present climate conditions and two simulated scenarios of the Intergovernmental Panel on Climate Change (IPCC): B1 (+1·8 °C) and A2 (+3·4 °C). Key Results Cold stratification released physiological dormancy, while very few seeds germinated without treatments or after warm stratification. Fresh, cold-stratified seeds germinated significantly better (>80 %) at temperatures ?20 °C than at lower temperatures. A base temperature for germination (Tb) of 9·0–11·3 °C and a thermal time requirement for 50 % of germination (?50) ranging from 33·6 °Cd to 68·6 °Cd were identified for non-dormant cold-stratified seeds, depending on the populations. This complex combination of thermal requirements for dormancy release and germination allowed prediction of field emergence from March to May under the present climatic conditions for the investigated populations. Conclusions The thermal thresholds for seed germination identified in this study (Tb and ?50) explained the differences in seed germination detected among populations. Under the two simulated IPCC scenarios, an altitude-related risk from climate warming is identified, with lowland populations being more threatened due to a compromised seed dormancy release and a narrowed seed germination window. PMID:23071219

Orrù, Martino; Mattana, Efisio; Pritchard, Hugh W.; Bacchetta, Gianluigi

2012-01-01

319

Climate change. Projected increase in lightning strikes in the United States due to global warming.  

PubMed

Lightning plays an important role in atmospheric chemistry and in the initiation of wildfires, but the impact of global warming on lightning rates is poorly constrained. Here we propose that the lightning flash rate is proportional to the convective available potential energy (CAPE) times the precipitation rate. Using observations, the product of CAPE and precipitation explains 77% of the variance in the time series of total cloud-to-ground lightning flashes over the contiguous United States (CONUS). Storms convert CAPE times precipitated water mass to discharged lightning energy with an efficiency of 1%. When this proxy is applied to 11 climate models, CONUS lightning strikes are predicted to increase 12 ± 5% per degree Celsius of global warming and about 50% over this century. PMID:25395536

Romps, David M; Seeley, Jacob T; Vollaro, David; Molinari, John

2014-11-14

320

Is equilibrium climate sensitivity the best predictor for future global warming? (Invited)  

NASA Astrophysics Data System (ADS)

When the climate system is subject to radiative forcing the planet is brought out of radiative balance and the thermal inertia of the planet makes the surface temperature lag behind the forcing. The time constant, which is the time for relaxation to a new equilibrium after a sudden change in forcing, has been considered to be an important parameter to determine. The equilibrium climate sensitivity Seq, the temperature raise per unit forcing after relaxation is complete, is another. In the industrialized epoch a major source for the present energy imbalance is the steady increase in anthropogenic forcing. If the climate system can be modeled as a hierarchy of interacting subsystems with increasing heat capacities and response times there will also be a hierarchy of climate sensitivities. One way of modeling this feature is to replace the standard exponentially decaying impulse-response function with one that is scale free, i.e., decaying like a power law. For a climate system which is subject only to random forcing modeled as a white Gaussian noise, the resulting climate variable is then a long-memory fractional Gaussian noise with a scale-free power spectral density. The final response to a step increase in the forcing is infinite for such a perfectly scale-free response function, since the response to an increase in the forcing will never saturate. This is of course unphysical, but rather than invalidating the scale-free response model it suggests the introduction of a frequency-dependent climate sensitivity S(f). Even in the exponential response model the amplitude response to an oscillation vanishes for high frequencies, but converges to Seq in the limit of low frequencies f. In the scale-free response model S(f) diverges in the low-frequency limit. We demonstrate that long-memory responses can explain important aspects of Northern hemisphere temperature variability over the last millennium and lead to new predictions of how much more warming there will be 'in the pipeline' in any given forcing scenario. The relation to scaling properties of local temperature data and spatial correlations in climate data is also discussed. References: Rypdal, M. and Rypdal, K.: Long-memory effects in linear-response models of Earth's temperature and implications for future global warming, submitted to J. Climate, http://arxiv.org/pdf/ 1305.5080v1.pdf, 2013. Rypdal, M. and Rypdal, K.: 'Predicting' northern hemisphere temperature for the previous millennium based on a parametric stochastic-dynamic model trained on the instrumental global temperature and forcing records, session PP012, this conference.

Rypdal, M.; Rypdal, K.

2013-12-01

321

Assessing Climate Change Impacts for Military Installations in the Southwest United States During the Warm Season  

NASA Astrophysics Data System (ADS)

Arid and semi-arid regions are experiencing some of the most adverse impacts of climate change with increased heat waves, droughts, and extreme weather. These events will likely exacerbate socioeconomic and political instabilities in regions where the United States has vital strategic interests and ongoing military operations. The Southwest U.S. is strategically important in that it houses some of the most spatially expansive and important military installations in the country. The majority of severe weather events in the Southwest occur in association with the North American monsoon system (NAMS), and current observational record has shown a 'wet gets wetter and dry gets drier' global monsoon precipitation trend. We seek to evaluate the warm season extreme weather projection in the Southwest U.S., and how the extremes can affect Department of Defense (DoD) military facilities in that region. A baseline methodology is being developed to select extreme warm season weather events based on historical sounding data and moisture surge observations from Gulf of California. Numerical Weather Prediction (NWP)-type high resolution simulations will be performed for the extreme events identified from Weather Research and Forecast (WRF) model simulations initiated from IPCC GCM and NCAR Reanalysis data in both climate control and climate change periods. The magnitude in extreme event changes will be analyzed, and the synoptic forcing patterns of the future severe thunderstorms will provide a guide line to assess if the military installations in the Southwest will become more or less susceptible to severe weather in the future.

Castro, C.

2013-05-01

322

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

PubMed

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

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

2015-01-01

323

Climate warming may facilitate invasion of the exotic shrub Lantana camara.  

PubMed

Plant species show different responses to the elevated temperatures that are resulting from global climate change, depending on their ecological and physiological characteristics. The highly invasive shrub Lantana camara occurs between the latitudes of 35 °N and 35 °S. According to current and future climate scenarios predicted by the CLIMEX model, climatically suitable areas for L. camara are projected to contract globally, despite expansions in some areas. The objective of this study was to test those predictions, using a pot experiment in which branch cuttings were grown at three different temperatures (22 °C, 26 °C and 30 °C). We hypothesized that warming would facilitate the invasiveness of L. camara. In response to rising temperatures, the total biomass of L. camara did increase. Plants allocated more biomass to stems and enlarged their leaves more at 26 °C and 30 °C, which promoted light capture and assimilation. They did not appear to be stressed by higher temperatures, in fact photosynthesis and assimilation were enhanced. Using lettuce (Lactuca sativa) as a receptor plant in a bioassay experiment, we also tested the phytotoxicity of L. camara leachate at different temperatures. All aqueous extracts from fresh leaves significantly inhibited the germination and seedling growth of lettuce, and the allelopathic effects became stronger with increasing temperature. Our results provide key evidence that elevated temperature led to significant increases in growth along with physiological and allelopathic effects, which together indicate that global warming facilitates the invasion of L. camara. PMID:25184224

Zhang, Qiaoying; Zhang, Yunchun; Peng, Shaolin; Zobel, Kristjan

2014-01-01

324

Climate Warming May Facilitate Invasion of the Exotic Shrub Lantana camara  

PubMed Central

Plant species show different responses to the elevated temperatures that are resulting from global climate change, depending on their ecological and physiological characteristics. The highly invasive shrub Lantana camara occurs between the latitudes of 35°N and 35°S. According to current and future climate scenarios predicted by the CLIMEX model, climatically suitable areas for L. camara are projected to contract globally, despite expansions in some areas. The objective of this study was to test those predictions, using a pot experiment in which branch cuttings were grown at three different temperatures (22°C, 26°C and 30°C). We hypothesized that warming would facilitate the invasiveness of L. camara. In response to rising temperatures, the total biomass of L. camara did increase. Plants allocated more biomass to stems and enlarged their leaves more at 26°C and 30°C, which promoted light capture and assimilation. They did not appear to be stressed by higher temperatures, in fact photosynthesis and assimilation were enhanced. Using lettuce (Lactuca sativa) as a receptor plant in a bioassay experiment, we also tested the phytotoxicity of L. camara leachate at different temperatures. All aqueous extracts from fresh leaves significantly inhibited the germination and seedling growth of lettuce, and the allelopathic effects became stronger with increasing temperature. Our results provide key evidence that elevated temperature led to significant increases in growth along with physiological and allelopathic effects, which together indicate that global warming facilitates the invasion of L. camara. PMID:25184224

Zhang, Qiaoying; Zhang, Yunchun; Peng, Shaolin; Zobel, Kristjan

2014-01-01

325

Adaptation to Global Warming: Do Climate Models Tell Us What We Need to Know? Author(s): Naomi Oreskes, David A. Stainforth, Leonard A. Smith  

E-print Network

Adaptation to Global Warming: Do Climate Models Tell Us What We Need to Know? Author(s): Naomi. All rights reserved. 1012 Adaptation to Global Warming: Do Climate Models Tell Us What We Need to Know) for a synthesis of three Intergovernmental Panel on Climate Change (IPCC) working groups. #12;ADAPTATION TO GLOBAL

Stevenson, Paul

326

The influence of convection parameterisations under alternate climate conditions  

NASA Astrophysics Data System (ADS)

In the last decades several convection parameterisations have been developed to consider the impact of small-scale unresolved processes in Earth System Models associated with convective clouds. Global model simulations, which have been performed under current climate conditions with different convection schemes, significantly differ among each other in the simulated precipitation patterns due to the parameterisation assumptions and formulations, e.g. the simplified treatment of the cloud microphysics. Additionally, the simulated transport of short-lived trace gases strongly depends on the chosen convection parameterisation due to the differences in the vertical redistribution of mass. Furthermore, other meteorological parameters like the temperature or the specific humidity show substantial differences in convectively active regions. This study presents uncertainties of climate change scenarios caused by different convection parameterisations. For this analysis two experiments (reference simulation with a CO2 concentration of 348 ppm; 2xCO2-simulation with a CO2 concentration of 696 ppm) are calculated with the ECHAM/MESSy atmospheric chemistry (EMAC) model applying four different convection schemes (Tiedtke, ECMWF, Emanuel and Zhang-McFarlane - Hack) and two resolutions (T42 and T63), respectively. The results indicate that the equilibrium climate sensitivity is independent of the chosen convection parameterisation. However, the regional temperature increase, induced by a doubling of the carbon dioxide concentration, demonstrates differences of up to a few Kelvin at the surface as well as in the UTLS for the ITCZ region depending on the selected convection parameterisation. The interaction between cloud and convection parameterisations results in a large disagreement of precipitation patterns. Although every 2xCO2 -experiment simulates an increase in global mean precipitation rates, the change of regional precipitation patterns differ widely. Finally, analysing the cloud radiative forcing a huge spread of the cloud-induced radiative flux change is found in the warm pool region due to a change of the convection parameterisation.

Rybka, Harald; Tost, Holger

2013-04-01

327

Climate Extremes Triggered State Shifting of US Great Plains Prairie under Experimental Warming  

NASA Astrophysics Data System (ADS)

Ecosystems can exist under multiple stable states. Transition from one stable state to another is usually triggered by perturbations such as climate extremes, which should be large enough to push the ecosystem over a threshold. Ecosystem state changes can alter ecosystem functions and services as dramatically as in Sahara with vegetation changes from tropical forests to grassland and deserts over 6000 years. Thus it is crucial to understand mechanisms underlying ecosystem state changes. State changes of ecosystem vegetation have been well documented in paleo-records and predicted to occur under climate change by dynamic global vegetation models. Paleo-records usually offer broad-scale patterns of ecosystem state changes over time and rarely offer much insight into fundamental mechanisms underlying the state changes. Model predictions may be calibrated against contemporary and paleo vegetation distributions but have not been carefully tested against experimental evidence. The latter, however, is extremely rare largely because global chance experiments are mostly short term. We have observed state shifting of a US Great Plains prairie under long-term experimental warming and clipping treatments. Our analysis of 11-year data from the experiment showed two-stage stimulations of aboveground net primary production (ANPP) with small increases in the first 7 followed by distinctly large increases under experimental warming in comparison with those under control. The two-stage ANPP simulations were corresponded with species reordering with the plant community over time but not related to warming-induced changes in temperature, soil moisture and nitrogen dynamics in the grassland. The state shifting of the grassland under the experimental warming was partly because our experimental site locates in an ecotone between the mixed and tall grass prairies. Under the experimental warming, the prairie was shifting from the mixed prairie as dominated by Schizachyrium scoparium (little blue stem) with a typical height of about 1 m to a typical tallgrass prairie dominated by Sorghastrum nutans (Indian grass) of about 2 m tall. Our results suggested that chronic experimental treatments differentially exerted impacts on individual species to certain thresholds, beyond which plant community structure and ecosystem functions were changing to a different state. , The threshold change was triggered by climate extremes with two consecutive drought years in 2005 and 2006 followed by a very wet year in 2007.

Luo, Y.; Xu, X.; Sherry, R.; Niu, S.; Li, D.; Xia, J.

2012-04-01

328

Using climate models to unraveling past conditions during Earth's history and its relevance to Climate Change  

Microsoft Academic Search

During the mid 1970s global climate models were used to examine climate conditions of the past. Initially these early studies considered how external changes would influence the climate system and the ocean was considered as a fixed boundary condition. By the early 1980s the ocean evolved from a fixed boundary condition, to one acting solely as a moisture source and

G. S. Jenkins

2002-01-01

329

The toxicology of climate change: environmental contaminants in a warming world.  

PubMed

Climate change induced by anthropogenic warming of the earth's atmosphere is a daunting problem. This review examines one of the consequences of climate change that has only recently attracted attention: namely, the effects of climate change on the environmental distribution and toxicity of chemical pollutants. A review was undertaken of the scientific literature (original research articles, reviews, government and intergovernmental reports) focusing on the interactions of toxicants with the environmental parameters, temperature, precipitation, and salinity, as altered by climate change. Three broad classes of chemical toxicants of global significance were the focus: air pollutants, persistent organic pollutants (POPs), including some organochlorine pesticides, and other classes of pesticides. Generally, increases in temperature will enhance the toxicity of contaminants and increase concentrations of tropospheric ozone regionally, but will also likely increase rates of chemical degradation. While further research is needed, climate change coupled with air pollutant exposures may have potentially serious adverse consequences for human health in urban and polluted regions. Climate change producing alterations in: food webs, lipid dynamics, ice and snow melt, and organic carbon cycling could result in increased POP levels in water, soil, and biota. There is also compelling evidence that increasing temperatures could be deleterious to pollutant-exposed wildlife. For example, elevated water temperatures may alter the biotransformation of contaminants to more bioactive metabolites and impair homeostasis. The complex interactions between climate change and pollutants may be particularly problematic for species living at the edge of their physiological tolerance range where acclimation capacity may be limited. In addition to temperature increases, regional precipitation patterns are projected to be altered with climate change. Regions subject to decreases in precipitation may experience enhanced volatilization of POPs and pesticides to the atmosphere. Reduced precipitation will also increase air pollution in urbanized regions resulting in negative health effects, which may be exacerbated by temperature increases. Regions subject to increased precipitation will have lower levels of air pollution, but will likely experience enhanced surface deposition of airborne POPs and increased run-off of pesticides. Moreover, increases in the intensity and frequency of storm events linked to climate change could lead to more severe episodes of chemical contamination of water bodies and surrounding watersheds. Changes in salinity may affect aquatic organisms as an independent stressor as well as by altering the bioavailability and in some instances increasing the toxicity of chemicals. A paramount issue will be to identify species and populations especially vulnerable to climate-pollutant interactions, in the context of the many other physical, chemical, and biological stressors that will be altered with climate change. Moreover, it will be important to predict tipping points that might trigger or accelerate synergistic interactions between climate change and contaminant exposures. PMID:19375165

Noyes, Pamela D; McElwee, Matthew K; Miller, Hilary D; Clark, Bryan W; Van Tiem, Lindsey A; Walcott, Kia C; Erwin, Kyle N; Levin, Edward D

2009-08-01

330

Competitive and demographic leverage points of community shifts under climate warming.  

PubMed

Accelerating rates of climate change and a paucity of whole-community studies of climate impacts limit our ability to forecast shifts in ecosystem structure and dynamics, particularly because climate change can lead to idiosyncratic responses via both demographic effects and altered species interactions. We used a multispecies model to predict which processes and species' responses are likely to drive shifts in the composition of a space-limited benthic marine community. Our model was parametrized from experimental manipulations of the community. Model simulations indicated shifts in species dominance patterns as temperatures increase, with projected shifts in composition primarily owing to the temperature dependence of growth, mortality and competition for three critical species. By contrast, warming impacts on two other species (rendering them weaker competitors for space) and recruitment rates of all species were of lesser importance in determining projected community changes. Our analysis reveals the importance of temperature-dependent competitive interactions for predicting effects of changing climate on such communities. Furthermore, by identifying processes and species that could disproportionately leverage shifts in community composition, our results contribute to a mechanistic understanding of climate change impacts, thereby allowing more insightful predictions of future biodiversity patterns. PMID:23658199

Sorte, Cascade J B; White, J Wilson

2013-07-01

331

Competitive and demographic leverage points of community shifts under climate warming  

PubMed Central

Accelerating rates of climate change and a paucity of whole-community studies of climate impacts limit our ability to forecast shifts in ecosystem structure and dynamics, particularly because climate change can lead to idiosyncratic responses via both demographic effects and altered species interactions. We used a multispecies model to predict which processes and species' responses are likely to drive shifts in the composition of a space-limited benthic marine community. Our model was parametrized from experimental manipulations of the community. Model simulations indicated shifts in species dominance patterns as temperatures increase, with projected shifts in composition primarily owing to the temperature dependence of growth, mortality and competition for three critical species. By contrast, warming impacts on two other species (rendering them weaker competitors for space) and recruitment rates of all species were of lesser importance in determining projected community changes. Our analysis reveals the importance of temperature-dependent competitive interactions for predicting effects of changing climate on such communities. Furthermore, by identifying processes and species that could disproportionately leverage shifts in community composition, our results contribute to a mechanistic understanding of climate change impacts, thereby allowing more insightful predictions of future biodiversity patterns. PMID:23658199

Sorte, Cascade J. B.; White, J. Wilson

2013-01-01

332

Regional climate response to land surface changes after harvest in the North China Plain under present and possible future climate conditions  

NASA Astrophysics Data System (ADS)

In this study, we investigated the impacts of land use alterations from harvesting practices on the regional surface climate over the North China Plain. The surface climate responses after harvest in June in regions where double-cropping is practiced were evaluated using observations and model simulations with the global climate model HadGEM2-Atmosphere. Responses were modeled under both present and possible future climate conditions. In the model, double-cropping was represented using the monthly varying fraction of vegetation. This contributed to an improvement in the model simulation over East Asia. Modeling results showed that the land surface was warmer and drier after harvest, and these simulation results were consistent with observations. The bare soil surface after harvest in June had biophysical impacts on the surface climate that were mediated by decreasing evapotranspiration and latent heat flux effects, which increased surface air temperatures and decreased surface humidity. An increase in shortwave radiation also contributed to the rise in temperatures. Under two Representative Concentration Pathways (RCP) scenarios for possible future climate conditions, land conversion induced additional warming in addition to greenhouse gases induced global warming. The RCP 8.5 and RCP 2.6 scenarios demonstrated a warming of 1.0°C and 1.4°C due to harvesting practices in June, respectively. The response magnitude was affected by the climate conditions in each RCP. Our results suggest that potential impacts of harvest on the local climate need to be considered in future projections of CO2-induced warming on a regional scale.

Cho, Mee-Hyun; Boo, Kyung-On; Lee, Johan; Cho, Chunho; Lim, Gyu-Ho

2014-04-01

333

Arctic climate change with a 2 ? C global warming: Timing, climate patterns and vegetation change  

Microsoft Academic Search

The signatories to United Nations Framework Convention on Climate Change are charged with stabilizing the concentrations of\\u000a greenhouse gases in the atmosphere at a level that prevents dangerous interference with the climate system. A number of nations,\\u000a organizations and scientists have suggested that global mean temperature should not rise over 2 ?C above preindustrial levels. However, even a relatively moderate

Jed O. Kaplan; Mark New

2006-01-01

334

A paleoscience approach to estimating the effects of climatic warming on salmonid fisheries of the Columbia River Basin  

SciTech Connect

To understand how climatic warming might affect salmonid populations, we are following a four-step procedure, incorporating paleoenvironmental data at the beginning and ending points, as follows. First, we used geomorphic, paleobotanical, and paleomalacological data to reconstruct stream conditions during the last 8000 years. Second, we estimated the effect on salmon of conditions extant approximately 6000 to 7000 radiocarbon years before present (B.P.), when temperatures were as much as 2{degrees}C warmer than at present. This became an analog of future warmer climate and its effects on spawning, incubation, and rearing parameters of the NPPC`s Tributary Parameter Model (TPM) for estimating salmoned production. Third, we ran the TPM in conjunction with the NPPC System Planning Model (SPM) to calculate the effect of these analog conditions on the population of returning adult fish in selected stream systems. Ultimately, we will run the models for all salmon-accessible subbasins of the Columbia River system. Finally, we are identifying fish remains obtained from archaeological sites along the Columbia River to compare variations in the taxonomic composition of ancient fish assemblages with model predictions.

Chatters, J.C.; Butler, V.L.; Scott, M.J.; Anderson, D.M.; Neitzel, D.A.

1992-10-01

335

A paleoscience approach to estimating the effects of climatic warming on salmonid fisheries of the Columbia River Basin  

SciTech Connect

To understand how climatic warming might affect salmonid populations, we are following a four-step procedure, incorporating paleoenvironmental data at the beginning and ending points, as follows. First, we used geomorphic, paleobotanical, and paleomalacological data to reconstruct stream conditions during the last 8000 years. Second, we estimated the effect on salmon of conditions extant approximately 6000 to 7000 radiocarbon years before present (B.P.), when temperatures were as much as 2[degrees]C warmer than at present. This became an analog of future warmer climate and its effects on spawning, incubation, and rearing parameters of the NPPC's Tributary Parameter Model (TPM) for estimating salmoned production. Third, we ran the TPM in conjunction with the NPPC System Planning Model (SPM) to calculate the effect of these analog conditions on the population of returning adult fish in selected stream systems. Ultimately, we will run the models for all salmon-accessible subbasins of the Columbia River system. Finally, we are identifying fish remains obtained from archaeological sites along the Columbia River to compare variations in the taxonomic composition of ancient fish assemblages with model predictions.

Chatters, J.C.; Butler, V.L.; Scott, M.J.; Anderson, D.M.; Neitzel, D.A.

1992-10-01

336

Warm Rain Processes over the Tropical Oceans and Implications on Climate Change: Results from TRMM and GEOS GCM  

NASA Technical Reports Server (NTRS)

In this talk, we will first show results from TRMM data regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to larger portion of the increase. The abundant rainout of warm precipitation causes a reduction of low and middle cloud amount due to rainout, and reduced high clouds due to less water vapor available for ice-phase convection. However, clod radiation feedback caused by the increased rainfall efficiency, leads to differential vertical heating/cooling producing a more unstable atmosphere, allowing, more intense, but isolated penetrative convection, with contracted anvils to develop. Results also show that increased autoconversion reduces the convective adjustment time scale, resulting in faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbances on daily to weekly time scales. The crucial link of precipitation microphysical processes to climate change including the effects of aerosols will be discussed.

Lau, William K. M.; Wu, H. T.

2004-01-01

337

Warm Rain Processes Over the Tropical Oceans and Implications on Climate Change: Results from TRMM and GOES GCM  

NASA Technical Reports Server (NTRS)

In this talk, we will first show results from TRMM data regarding the characteristics of warm rains over the tropical oceans, and the dependence of rate of warm rain production on sea surface temperature. Results lead to the hypothesis that warm rain production efficiency, i.e., autoconversion, may be increased in a warm climate. We use the GEOS-II GCM to test this hypothesis. Our modeling results show that in a climate with increased rate of autoconversion, the total rain amount is increased, with warm rain contributing to a larger portion of the increase. The abundant rainout of warm precipitation causes a reduction of low and middle cloud amount due to rainout, and reduced high clouds due to less water vapor available for ice-phase convection. However, clod radiation feedback caused by the increased rainfall efficiency, leads to differential vertical heating/cooling producing a more unstable atmosphere, allowing, more intense, but isolated penetrative convection, with contracted anvils to develop. Results also show that increased autoconversion reduces the convective adjustment time scale, resulting in faster recycling of atmospheric water. Most interestingly, the increased low level heating associated with warm rain leads to more energetic Madden and Julian oscillations in the tropics, with well-defined eastward propagation. While reducing the autoconversion leads to an abundant mix of westward and eastward tropical disturbances on daily to weekly time scales. The crucial link of precipitation microphysical processes to climate change including the effects of aerosols will be discussed.

Lau, William K. M.; Wu, H. T.

2004-01-01

338

Changing forest water yields in response to climate warming: Results from long-term experimental watershed sites across North America  

NASA Astrophysics Data System (ADS)

Climate warming is projected to affect forest catchment water yields, but effects may vary among biomes. We hypothesized that catchments where water yields have varied relatively little in response to climate warming would be more resilient to warming effects than other types of catchments are. To test this hypothesis, we examined the variability in historical catchment water yields at long-term experimental watershed sites across Canada and the United States. Using the theoretical framework of the Budyko curve, which estimates catchment evaporation as a function of catchment dryness, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation was defined as a catchment's change in actual ET divided by P (AET/P) coincident with a shift from a cool to warm period. Elasticity was defined as the ratio of inter-annual variation in potential ET divided by P (PET/P, the dryness index) to inter-annual variation in actual ET divided by P (AET/P, the evaporative index). Deviation in water yields was related to elasticity. Alpine sites showed greatest sensitivity to climate warming with any warming leading to increased water yields. Conifer sites included catchments with lowest elasticity and had stable to higher water yields, deciduous sites included catchments with intermediate elasticity and had stable to lower water yields, and mixed forests included catchments with highest elasticity and had stable water yields. For all forest types, there was a tendency for elasticity to converge to 1.0 with forest age. Both forest type and age were determinants of elasticity, which leads to resilience of catchment water yields to climate warming.

Jones, J. A.; Creed, I. F.; Spargo, A.; Buttle, J. M.; Adams, M.; Beall, F. D.; Booth, E.; Campbell, J. L.; Clow, D. W.; Elder, K.; Ford, C. R.; Grimm, N. B.; Ramlal, P.; Saha, A.; Sebestyen, S. D.; Spittlehouse, D.; Sterling, S. M.; Williams, M. W.; Winkler, R. D.; Yao, H.

2013-12-01

339

Impact of a permanent El Niño (El Padre) and Indian Ocean Dipole in warm Pliocene climates  

NASA Astrophysics Data System (ADS)

Pliocene sea surface temperature data, as well as terrestrial precipitation and temperature proxies, indicate warmer than modern conditions in the eastern equatorial Pacific and imply permanent El Niño-like conditions with impacts similar to those of the 1997/1998 El Niño event. Here we use a general circulation model to examine the global-scale effects that result from imposing warm tropical sea surface temperature (SST) anomalies in both modern and Pliocene simulations. Observed SSTs from the 1997/1998 El Niño event were used for the anomalies and incorporate Pacific warming as well as a prominent Indian Ocean Dipole event. Both the permanent El Niño (also called El Padre) and Indian Ocean Dipole (IOD) conditions are necessary to reproduce temperature and precipitation patterns consistent with the global distribution of Pliocene proxy data. These patterns may result from the poleward propagation of planetary waves from the strong convection centers associated with the El Niño and IOD.

Shukla, Sonali P.; Chandler, Mark A.; Jonas, Jeff; Sohl, Linda E.; Mankoff, Ken; Dowsett, Harry

2009-06-01

340

Sensitivity of the atmospheric response to warm pool El Niño events to modeled SSTs and future climate forcings  

NASA Astrophysics Data System (ADS)

Warm pool El Niño (WPEN) events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific. Under present-day climate conditions, WPEN events generate poleward propagating wavetrains and enhance midlatitude planetary wave activity, weakening the stratospheric polar vortices. The late 21st century extratropical atmospheric response to WPEN events is investigated using the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM), version 2. GEOSCCM simulations are forced by projected late 21st century concentrations of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) and by SSTs and sea ice concentrations from an existing ocean-atmosphere simulation. Despite known ocean-atmosphere model biases, the prescribed SST fields represent a best estimate of the structure of late 21st century WPEN events. The future Arctic vortex response is qualitatively similar to that observed in recent decades but is weaker in late winter. This response reflects the weaker SST forcing in the Niño 3.4 region and subsequently weaker Northern Hemisphere tropospheric teleconnections. The Antarctic stratosphere does not respond to WPEN events in a future climate, reflecting a change in tropospheric teleconnections: The meridional wavetrain weakens while a more zonal wavetrain originates near Australia. Sensitivity simulations show that a strong poleward wavetrain response to WPEN requires a strengthening and southeastward extension of the South Pacific Convergence Zone; this feature is not captured by the late 21st century modeled SSTs. Expected future increases in GHGs and decreases in ODSs do not affect the polar stratospheric responses to WPEN.

Hurwitz, Margaret M.; Garfinkel, Chaim I.; Newman, Paul A.; Oman, Luke D.

2013-12-01

341

Sensitivity of the Atmospheric Response to Warm Pool El Nino Events to Modeled SSTs and Future Climate Forcings  

NASA Technical Reports Server (NTRS)

Warm pool El Nino (WPEN) events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific. Under present-day climate conditions, WPEN events generate poleward propagating wavetrains and enhance midlatitude planetary wave activity, weakening the stratospheric polar vortices. The late 21st century extratropical atmospheric response to WPEN events is investigated using the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM), version 2. GEOSCCM simulations are forced by projected late 21st century concentrations of greenhouse gases (GHGs) and ozone-depleting substances (ODSs) and by SSTs and sea ice concentrations from an existing ocean-atmosphere simulation. Despite known ocean-atmosphere model biases, the prescribed SST fields represent a best estimate of the structure of late 21st century WPEN events. The future Arctic vortex response is qualitatively similar to that observed in recent decades but is weaker in late winter. This response reflects the weaker SST forcing in the Nino 3.4 region and subsequently weaker Northern Hemisphere tropospheric teleconnections. The Antarctic stratosphere does not respond to WPEN events in a future climate, reflecting a change in tropospheric teleconnections: The meridional wavetrain weakens while a more zonal wavetrain originates near Australia. Sensitivity simulations show that a strong poleward wavetrain response to WPEN requires a strengthening and southeastward extension of the South Pacific Convergence Zone; this feature is not captured by the late 21st century modeled SSTs. Expected future increases in GHGs and decreases in ODSs do not affect the polar stratospheric responses to WPEN.

Hurwitz, Margaret M.; Garfinkel, Chaim I.; Newman, Paul A.; Oman, Luke D.

2013-01-01

342

Relative effects of multi-decadal climatic variability and changes in the mean and variability of climate due to global warming: future streamflows in Britain  

Microsoft Academic Search

Climate change impact assessments conventionally assess just the implications of a change in mean climate due to global warming. This paper compares such effects of such changes with those due to natural multi-decadal variability, and also explores the effects of changing the year-to-year variability in climate as well as the mean. It estimates changes in mean monthly flows and a

Nigel W Arnell

2003-01-01

343

Global Farm Animal Production and Global Warming: Impacting and Mitigating Climate Change  

PubMed Central

Background The farm animal sector is the single largest anthropogenic user of land, contributing to many environmental problems, including global warming and climate change. Objectives The aim of this study was to synthesize and expand upon existing data on the contribution of farm animal production to climate change. Methods We analyzed the scientific literature on farm animal production and documented greenhouse gas (GHG) emissions, as well as various mitigation strategies. Discussions An analysis of meat, egg, and milk production encompasses not only the direct rearing and slaughtering of animals, but also grain and fertilizer production for animal feed, waste storage and disposal, water use, and energy expenditures on farms and in transporting feed and finished animal products, among other key impacts of the production process as a whole. Conclusions Immediate and far-reaching changes in current animal agriculture practices and consumption patterns are both critical and timely if GHGs from the farm animal sector are to be mitigated. PMID:18470284

Koneswaran, Gowri; Nierenberg, Danielle

2008-01-01

344

Examining Impact of Global warming on the summer monsoon system using regional Climate Model (PRECIS)  

NASA Astrophysics Data System (ADS)

Every year, southwest monsoon arrives over Indian region with remarkable regularity. It hits the southern state of Kerala first by the end of May or the early June. More than 70% of the annual precipitation is received during the four monsoon months viz. June to September. This monsoon rainfall is vital for the agriculture as well as for the yearly needs of Indian population. The performance of the monsoon depends on the timely onset over southern tip of India and its progress along the entire country. This northward progression of monsoon to cover the entire Indian landmass, many times, is associated with the formation of synoptic scale system in the Bay of Bengal region and their movement along the monsoon trough region. The analysis of the observed cyclonic disturbances show that their frequency has reduced in recent decades. It is, therefore, necessary to assess the effect of global warming on the monsoon climate of India. A state-of-art regional climate modelling system, known as PRECIS (Providing REgional Climates for Impacts Studies) developed by the Hadley Centre for Climate Prediction and Research, U.K. is applied over the South Asian domain to investigate the impact of global warming on the cyclonic disturbances. The PRECIS simulations at 50 km x 50 km horizontal resolution are made for two time slices, present (1961-1990) and the future (2071-2100), for two socio-economic scenarios A2 and B2. The model skills are evaluated using observed precipitation and surface air temperature. The model has shown reasonably good skill in simulating seasonal monsoon rainfall, whereas cold bias is seen in surface air temperature especially in post-monsoon months. The typical monsoon features like monsoon trough, precipitation maxima over west coast and northeast India are well simulated by the model. The model simulations under the scenarios of increasing greenhouse gas concentrations and sulphate aerosols are analysed to study the likely changes in the quasi-permanent systems related to the monsoon climate over India viz. monsoon circulation, heat low over northwest India, mean sea level pressures along monsoon trough region, towards the end of the 21st century. The analysis of the model outputs indicate the weakening of monsoon circulation in the future. The mean sea level pressures in head bay of Bengal regions may be higher in future indicating the less frequent cyclonic disturbances in the Bay of Bengal region, under the effect of global warming.

Patwardhan, S. K.; Kundeti, K.; Krishna Kumar, K.

2011-12-01

345

Nitrogen partitioning in oak leaves depends on species, provenance, climate conditions and soil type.  

PubMed

Climate-tolerant tree species and/or provenances have to be selected to ensure the high productivity of managed forests in Central Europe under the prognosticated climate changes. For this purpose, we studied the responses of saplings from three oak species (i.e. Quercus robur, Q. petraea and Q. pubescens) and provenances of different climatic origin (i.e. low or high rainfall, low or high temperature habitats) with regard to leaf nitrogen (N) composition as a measure of N nutrition. Saplings were grown in model ecosystems on either calcareous or acidic soil and subjected to one of four treatments (control, drought, air warming or a combination of drought and air warming). Across species, oak N metabolism responded to the influence of drought and/or air warming with an increase in leaf amino acid N concentration at the expense of structural N. Moreover, provenances or species from drier habitats were more tolerant to the climate conditions applied, as indicated by an increase in amino acid N (comparing species) or soluble protein N (comparing provenances within a species). Furthermore, amino acid N concentrations of oak leaves were significantly higher on calcareous compared to acidic soil. From these results, it can be concluded that seeds from provenances or species originating from drier habitats and - if available - from calcareous soil types may provide a superior seed source for future forest establishment. PMID:22934888

Hu, B; Simon, J; Kuster, T M; Arend, M; Siegwolf, R; Rennenberg, H

2013-01-01

346

Impact of climate warming-induced increase in drought stress on successional dynamic of a coniferous forest within a dry inner Alpine environment  

NASA Astrophysics Data System (ADS)

Climate sensitivity of tree growth will effect the development of forest ecosystems under a warmer and drier climate by changing species composition and inducing shifts in forest distribution. We applied dendroclimatological techniques to determine impact of climate warming on radial stem growth of three native and widespread coniferous tree species of the central Austrian Alps (Norway spruce, Picea abies; European larch, Larix decidua; Scots pine, Pinus sylvestris), which grow intermixed at dry-mesic sites within a dry inner Alpine environment (750 m a.s.l., Tyrol, Austria). Time series of annual increments were developed from > 250 saplings and mature trees. Radial growth response to recent climate warming was explored by means of moving response functions (MRF) and evaluation of trends in basal area increment (BAI) for the period 1911 - 2009. Climate-growth relationships revealed significant differences among species in response to water availability. While precipitation in May - June favoured radial growth of spruce and larch, Scots pine growth mainly depended on April - May precipitation. Spruce growth was most sensitive to May - June temperature (inverse relationship). Although MRF coefficients indicated increasing drought sensitivity of all species, which is most likely related to intensified belowground competition for scarce water with increasing stand density and higher evapotranspiration rates due to climate warming, recent BAI trends strikingly differed among species. While BAI of larch was distinctly declining, spruce showed steadily increasing BAI and quite constant BAI was maintained in drought adapted Scots pine, although at lowest level of all species. Furthermore, more favourable growing conditions of spruce in recent decades are indicated by scattered natural regeneration and higher growth rates of younger trees during first decades of their lifespan. Because human interference and wildlife stock is negligible within the study area, results suggest a competitive advantage of shade-tolerant and shallow-rooted late successional spruce over early successional species, whereby the spruce`s competitive strength is most likely related to synergistic effects of shade-tolerance and efficient uptake of small rainfall events by fine roots distributed primarily in upper soil layers. On the other hand, strikingly decreasing trend in BAI of larch is suggested to be due to negative influence of climate warming on tree water status. We conclude that climate warming-induced increase in drought sensitivity changed competitive strength of co-occurring conifers due to differences in inherent adaptive capacity at a drought-prone inner Alpine site.

Schuster, R.; Zeisler, B.; Oberhuber, W.

2012-04-01

347

Arctic shelf flooding: a negative feedback on climate warming during terminations  

NASA Astrophysics Data System (ADS)

Glacial terminations are characterized by a strong rise in sea level related to melting ice sheets. This rise in sea level is not uniform all over the world, because regional effects (uplift and subsidence of coastal zones) are superimposed on global trends. For the Laptev Sea, Bauch et al. (2001) have shown that during the early Holocene the shelf area became flooded from 8.9 ka BP (-31 m) to 7.5 ka BP (-7 m, close to modern day coastline). An extrapolation of this result on the basis of modern bathymetry suggests that a far bigger area, covering the entire East Siberian Sea, became flooded at that time. This area is currently known as a sea-ice production zone (Tamura and Ohshima, 2010) and contributes significantly to the sea-ice exported from the Arctic through the Fram Strait (~20% of annual sea-ice area passing Fram Strait, Rigor and Colony, 1997). This leads to the following hypothesis: during times of lower sea levels, the coastline advances closer to the shelf break and reduces the amount of sea-ice production on these shelves, reducing sea-ice volume and export through Fram Strait and causing the sea-ice extent to retreat in the Nordic Seas, yielding warmer and saltier sea surface conditions. We have tested this hypothesis in a ocean-sea-ice-atmosphere coupled model of intermediate complexity (LOVECLIM), thereby focusing on an early Holocene (9 ka BP) test case. We use the results of 9 snapshot simulations with different model configurations, differing in land-sea-mask, manually prescribed ice sheets and melt fluxes from the Laurentide Ice sheet and the Greenland Ice sheet. Simulations with an unflooded East Siberian shelf show lower sea-ice production, a retreat of the sea-ice extent in the Nordic Seas and an increase in temperature and salinity on the northern East Greenland Current. Together with the retreating sea ice cover, local deep convection shifts from south of the Denmark Strait up to 9 degrees north, following the sea ice edge and resulting in heat release and surface warming during the entire year. Our analysis exhibits a surprising connection between increased sea-ice export through Fram Strait and changes in atmospheric winds that result from modifications in the atmospheric circulation, that are forced by changes in differential heating over the East Siberian Shelf and the Nordic Seas. This atmospheric teleconnection clearly shows that regional changes can affect hemispheric changes. In a first comparison with available sea-ice proxy reconstructions our results do not disagree, but show the necessity of increased temporal and spatial coverage of proxy reconstructions for future investigations. Our results indicate that shelf flooding had a significant impact on the climate during the early Holocene, namely reducing sea-ice cover and affecting atmospheric circulation. During terminations this can be considered to be a negative feedback on the progress of the termination, as a shelf area becomes flooded, sea-ice production and extent are likely to increase and reduce high latitude intake of orbitally-forced insolation, slowing down the warming trend. This can be the cause of observed cold reversals during warming phases in the continuous transformation of a glacial to an interglacial climate. This implies that shelf flooding should be taken into account when studying the climate dynamics during all glacial terminations. References Bauch, H.; Mueller-Lupp, T.; Taldenkova, E.; Spielhagen, R.; Kassens, H.; Grootes, P.; Thiede, J.; Heinemeier, J. & Petryashov, V. Chronology of the Holocene transgression at the North Siberian margin, Global and Planetary Change, 2001, 31, 125 - 139 Rigor, I. & Colony, R., Sea-ice production and transport of pollutants in the Laptev Sea, 1979-1993, Science of The Total Environment, Environmental Radioactivity in the Arctic, 1997, 202, 89-110 Tamura, T. & Ohshima, K. I., Mapping of sea ice production in the Arctic coastal polynyas, J. Geophys. Res., AGU, 2011, 116, C07030-

Blaschek, Michael; Renssen, Hans

2013-04-01

348

A warm and wet Little Climatic Optimum and a cold and dry Little Ice Age in the southern Rocky Mountains, USA  

SciTech Connect

In the next century, increases in atmospheric trace gas concentration could warm the global average temperature beyond what it has ranged during the past century. Examination of larger-than-historic climatic changes that have occurred in the past in specific regions provides realistic context for evaluating such potential future changes. This paper has contrasted the climatic manifestation of the Little Climatic Optimum or Medieval Warm Period (AD 900--1300) with that of the Little Ice Age (AD 1300--1850) in the northern Colorado Plateau region of the southwestern USA. The zenith of the Anasazi occupation coincides with the former and their demise coincides with the latter, when conditions became too cold and especially dry (in the summer) to support upland dry farming. During the height of the Little Climatic Optimum the region was characterized by a relatively long growing season and greater winter and summer precipitation than that of today. This resulted in a relatively rapid development of a potential dry-farming belt that was twice as wide as the present and areas that cannot be dry farmed today were routinely farmed by the Anasazi. Such conditions would be beneficial to dry farmers in the Four Corners region if those conditions were repeated in the near future.

Petersen, K.L.

1992-05-01

349

Subsurface warming in the subpolar North Atlantic during rapid climate events in the Early and Mid-Pleistocene  

NASA Astrophysics Data System (ADS)

A new high-resolution reconstruction of the temperature and salinity of the subsurface waters using paired Mg/Ca-?18O measurements on the planktonic foraminifera Neogloboquadrina pachyderma sinistrorsa (sin.) was conducted on a deep-sea sediment core in the subpolar North Atlantic (Site U1314). This study aims to reconstruct millennial-scale subsurface hydrography variations during the Early and Mid-Pleistocene (MIS 31-19). These rapid climate events are characterized by abrupt shifts between warm/cold conditions, and ice-sheet oscillations, as evidenced by major ice rafting events recorded in the North Atlantic sediments (Hernández-Almeida et al., 2012), similar to those found during the Last Glacial period (Marcott et al, 2011). The Mg/Ca derived paleotemperature and salinity oscillations prior and during IRD discharges at Site U1314 are related to changes in intermediate circulation. The increases in Mg/Ca paleotemperatures and salinities during the IRD event are preceded by short episodes of cooling and freshening of subsurface waters. The response of the AMOC to this perturbation is an increased of warm and salty water coming from the south, transported to high latitudes in the North Atlantic beneath the thermocline. This process is accompanied by a southward shift in the convection cell from the Nordic Seas to the subpolar North Atlantic and better ventilation of the North Atlantic at mid-depths. Poleward transport of warm and salty subsurface subtropical waters causes intense basal melting and thinning of marine ice-shelves, that culminates in large-scale instability of the ice sheets, retreat of the grounding line and iceberg discharge. The mechanism proposed involves the coupling of the AMOC with ice-sheet dynamics, and would explain the presence of these fluctuations before the establishment of high-amplitude 100-kyr glacial cycles. Hernández-Almeida, I., Sierro, F.J., Cacho, I., Flores, J.A., 2012. Impact of suborbital climate changes in the North Atlantic on ice sheet dynamics at the Mid-Pleistocene Transition. Paleoceanography 27, PA3214. Marcott, S.A., Clark, P.U., Padman, L., Klinkhammer, G.P., Springer, S.R., Liu, Z., Otto-Bliesner, B.L., Carlson, A.E., Ungerer, A., Padman, J., He, F., Cheng, J., Schmittner, A., 2011. Ice-shelf collapse from subsurface warming as a trigger for Heinrich events. Proceedings of the National Academy of Sciences 108, 13415-13419

Hernández-Almeida, Iván; Sierro, Francisco; Cacho, Isabel; Abel Flores, José

2014-05-01

350

Possible Asynchronous Glacial Expansion During Climatic Warming in the Holocene, Glacier Bay Region, Alaska  

NASA Astrophysics Data System (ADS)

Glacial expansion is commonly thought to occur during cold climatic periods whereas thinning and recession follow as the climate warms. However, data from Glacier Bay, Alaska, on the location and timing of ice margin positions suggest that ice growth of the terrestrial and tidewater systems continued long after warming began. Radiocarbon dating of trees overridden by glacial advance provide rates and positions of ice margins over the last 9500 years BP. Major periods of ice advance were initiated prior to 9500 yrs BP and continued through at least 6000 yrs BP. Similarly ice returned to the region around 4900 yrs BP and continued to expand apparently without interruption through 3200 yrs BP. Data from more recent periods of ice advance are not as well constrained but appear to suggest ice filled much of the bay, perhaps including parts of the ice mass remaining from the 4.9 K advance, during three separate periods including the Little Ice age. Current investigations are evaluating signals in the tree ring record for causes, including signals developed by external forcings such as El Nino, the Pacific Decadal Oscillation (PDO) and Arctic Oscillation(AO).

Lawson, D. E.; Finnegan, D. C.; Bigl, S. R.; Kopczynski, S. E.; Magilligan, F. J.

2003-12-01

351

Responses of butterflies to twentieth century climate warming: implications for future ranges.  

PubMed Central

We analyse distribution records for 51 British butterfly species to investigate altitudinal and latitudinal responses to twentieth century climate warming. Species with northern and/or montane distributions have disappeared from low elevation sites and colonized sites at higher elevations during the twentieth century, consistent with a climate explanation. We found no evidence for a systematic shift northwards across all species, even though 11 out of 46 southerly distributed species have expanded in the northern part of their distributions. For a subset of 35 species, we model the role of climate in limiting current European distributions and predict potential future distributions for the period 2070-2099. Most northerly distributed species will have little opportunity to expand northwards and will disappear from areas in the south, resulting in reduced range sizes. Southerly distributed species will have the potential to shift northwards, resulting in similar or increased range sizes. However, 30 out of 35 study species have failed to track recent climate changes because of lack of suitable habitat, so we revised our estimates accordingly for these species and predicted 65% and 24% declines in range sizes for northern and southern species, respectively. These revised estimates are likely to be more realistic predictions of future butterfly range sizes. PMID:12396492

Hill, J K; Thomas, C D; Fox, R; Telfer, M G; Willis, S G; Asher, J; Huntley, B

2002-01-01

352

Native bees buffer the negative impact of climate warming on honey bee pollination of watermelon crops.  

PubMed

If climate change affects pollinator-dependent crop production, this will have important implications for global food security because insect pollinators contribute to production for 75% of the leading global food crops. We investigate whether climate warming could result in indirect impacts upon crop pollination services via an overlooked mechanism, namely temperature-induced shifts in the diurnal activity patterns of pollinators. Using a large data set on bee pollination of watermelon crops, we predict how pollination services might change under various climate change scenarios. Our results show that under the most extreme IPCC scenario (A1F1), pollination services by managed honey bees are expected to decline by 14.5%, whereas pollination services provided by most native, wild taxa are predicted to increase, resulting in an estimated aggregate change in pollination services of +4.5% by 2099. We demonstrate the importance of native biodiversity in buffering the impacts of climate change, because crop pollination services would decline more steeply without the native, wild pollinators. More generally, our study provides an important example of how biodiversity can stabilize ecosystem services against environmental change. PMID:23704044

Rader, Romina; Reilly, James; Bartomeus, Ignasi; Winfree, Rachael

2013-10-01

353

Can ozone depletion and global warming interact to produce rapid climate change?  

PubMed Central

The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate trends during the past few decades is marked by rapid cooling and ozone depletion in the polar lower stratosphere of both hemispheres, coupled with an increasing strength of the wintertime westerly polar vortex and a poleward shift of the westerly wind belt at the earth's surface. Annular modes of variability are fundamentally a result of internal dynamical feedbacks within the climate system, and as such can show a large response to rather modest external forcing. The dynamics and thermodynamics of these modes are such that strong synergistic interactions between stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible for the pronounced changes in tropospheric and stratospheric climate observed during the past few decades. If these trends continue, they could have important implications for the climate of the 21st century. PMID:10677475

Hartmann, Dennis L.; Wallace, John M.; Limpasuvan, Varavut; Thompson, David W. J.; Holton, James R.

2000-01-01

354

Linking climate change and biological invasions: Ocean warming facilitates nonindigenous species invasions.  

PubMed

The spread of exotic species and climate change are among the most serious global environmental threats. Each independently causes considerable ecological damage, yet few data are available to assess whether changing climate might facilitate invasions by favoring introduced over native species. Here, we compare our long-term record of weekly sessile marine invertebrate recruitment with interannual variation in water temperature to assess the likely effect of climate change on the success and spread of introduced species. For the three most abundant introduced species of ascidian (sea squirt), the timing of the initiation of recruitment was strongly negatively correlated with winter water temperature, indicating that invaders arrived earlier in the season in years with warmer winters. Total recruitment of introduced species during the following summer also was positively correlated with winter water temperature. In contrast, the magnitude of native ascidian recruitment was negatively correlated with winter temperature (more recruitment in colder years) and the timing of native recruitment was unaffected. In manipulative laboratory experiments, two introduced compound ascidians grew faster than a native species, but only at temperatures near the maximum observed in summer. These data suggest that the greatest effects of climate change on biotic communities may be due to changing maximum and minimum temperatures rather than annual means. By giving introduced species an earlier start, and increasing the magnitude of their growth and recruitment relative to natives, global warming may facilitate a shift to dominance by nonnative species, accelerating the homogenization of the global biota. PMID:12422019

Stachowicz, John J; Terwin, Jeffrey R; Whitlatch, Robert B; Osman, Richard W

2002-11-26

355

Can ozone depletion and global warming interact to produce rapid climate change?  

PubMed

The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate trends during the past few decades is marked by rapid cooling and ozone depletion in the polar lower stratosphere of both hemispheres, coupled with an increasing strength of the wintertime westerly polar vortex and a poleward shift of the westerly wind belt at the earth's surface. Annular modes of variability are fundamentally a result of internal dynamical feedbacks within the climate system, and as such can show a large response to rather modest external forcing. The dynamics and thermodynamics of these modes are such that strong synergistic interactions between stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible for the pronounced changes in tropospheric and stratospheric climate observed during the past few decades. If these trends continue, they could have important implications for the climate of the 21st century. PMID:10677475

Hartmann, D L; Wallace, J M; Limpasuvan, V; Thompson, D W; Holton, J R

2000-02-15

356

The Spacing of Ceiling Fans for Human Comfort in Warm Temperature Conditions  

E-print Network

THE SPACING OF CEILING FANS FOR HUMAN COMFORT IN WARM TEMPERATURE CONDITIONS Syd Spain, Ph.D. Research Specialist CRS Sirrine, Inc. Houston, Tx ABSTRACT Airspeed tests of a commerci a1 1 y popular 52 in. ceiling fan operating at a low speed...

Spain, S.

1987-01-01

357

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

Microsoft Academic Search

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming.

S. Fischer; J. Sand; V. Baxter

1997-01-01

358

Plants, Birds and Butterflies: Short-Term Responses of Species Communities to Climate Warming Vary by Taxon and with Altitude  

PubMed Central

As a consequence of climate warming, species usually shift their distribution towards higher latitudes or altitudes. Yet, it is unclear how different taxonomic groups may respond to climate warming over larger altitudinal ranges. Here, we used data from the national biodiversity monitoring program of Switzerland, collected over an altitudinal range of 2500 m. Within the short period of eight years (2003–2010), we found significant shifts in communities of vascular plants, butterflies and birds. At low altitudes, communities of all species groups changed towards warm-dwelling species, corresponding to an average uphill shift of 8 m, 38 m and 42 m in plant, butterfly and bird communities, respectively. However, rates of community changes decreased with altitude in plants and butterflies, while bird communities changed towards warm-dwelling species at all altitudes. We found no decrease in community variation with respect to temperature niches of species, suggesting that climate warming has not led to more homogenous communities. The different community changes depending on altitude could not be explained by different changes of air temperatures, since during the 16 years between 1995 and 2010, summer temperatures in Switzerland rose by about 0.07°C per year at all altitudes. We discuss that land-use changes or increased disturbances may have prevented alpine plant and butterfly communities from changing towards warm-dwelling species. However, the findings are also consistent with the hypothesis that unlike birds, many alpine plant species in a warming climate could find suitable habitats within just a few metres, due to the highly varied surface of alpine landscapes. Our results may thus support the idea that for plants and butterflies and on a short temporal scale, alpine landscapes are safer places than lowlands in a warming world. PMID:24416144

Roth, Tobias; Plattner, Matthias; Amrhein, Valentin

2014-01-01

359

The Arctic freshwater cycle during a naturally and an anthropogenically induced warm climate  

NASA Astrophysics Data System (ADS)

The Arctic freshwater cycle plays an important role in regulating regional and global climate. Current observations suggest that an intensification of the high-northern latitude hydrological cycle has caused a freshening of the Arctic and sub-Arctic seas, increasing the potential of weakening overturning strength in the Nordic seas, and reducing temperatures. It is not known if this freshening is a manifestation of the current anthropogenic warming and if the Arctic freshwater cycle has exhibited similar changes in the past, in particular as a response to naturally induced periods of warming, for example during the mid-Holocene hypsithermal. Thus, we have used an earth model of intermediate complexity, LOVECLIM, to investigate the response of the Arctic freshwater cycle, during two warm periods that evolved under different sets of forcings, the mid-Holocene and the twenty-first century. A combination of proxy reconstructions and modelling studies have shown these two periods to exhibit similar surface temperature anomalies, compared to the pre-industrial period, however, it has yet to be determined if the Arctic freshwater cycle and thus, the transport and redistribution of freshwater to the Arctic and the sub-Arctic seas, during these two warm periods, is comparable. Here we provide an overview that shows that the response of the Arctic freshwater cycle during the first half of the twenty-first century can be interpreted as an `extreme' mid-Holocene hydrological cycle. Whilst for the remainder of the twenty-first century, the Arctic freshwater cycle and the majority of its components will likely transition into what can only be described as truly anthropogenic in nature.

Davies, Frazer J.; Renssen, Hans; Goosse, Hugues

2014-04-01

360

Does climate warming stimulate or inhibit soil protist communities? A test on testate amoebae in high-arctic tundra with free-air temperature increase.  

PubMed

Soil testate amoebae assemblages in a grassland area at Zackenberg (Northeast Greenland) were subjected to simulated climate-warming during the growing season using the Free-Air Temperature Increase technique. Samples were collected in upper (0 - 3cm) and deeper (3 - 6cm) soil horizons. Mean temperature elevations at 2.5 and 7.5 cm depth were 2.58 ± SD 1.11 and 2.13±SD 0.77°C, respectively, and did not differ significantly. Soil moisture in the top 11cm was not affected by the warming. During the manipulation, the densities of living amoebae and empty shells were higher in the experimental plots but only in the upper layer. Possibly, testate amoebae in the deeper layer were limited by other factors, suggesting that warming enhances the carrying capacity only in favourable conditions. Species richness, on the other hand, was only increased in the deeper horizon. Warming did not change the percentage of individuals belonging to small-sized species in any of the living assemblages, contrary to our expectation that those species would quickly increase their density. However, in the empty shell assemblages, the proportion of small-sized individuals in the experimental plots was higher in both layers, indicating a rapid, transient increase in small amoebae before the first sampling date. Changes in successional state of testate amoebae assemblages in response to future climate change might thus be ephemeral, whereas alterations in density and species richness might be more sustained. PMID:20708962

Tsyganov, Andrey N; Nijs, Ivan; Beyens, Louis

2011-04-01

361

BVOCs emission in a semi-arid grassland under climate warming and nitrogen deposition  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) profoundly affect atmospheric chemistry and ecosystem functioning. BVOCs emission and their responses to global change are still unclear in grasslands, which cover one quarter of the Earth's land surface and are currently undergoing the largest changes. Over two growing seasons, we conducted a field experiment in a semi-arid grassland (Inner Mongolia, China) to examine the emission and the responses of BVOCs emissions to warming and nitrogen deposition. The natural emission rate (NER) of monoterpene (dominant BVOCs here) is 107 ± 16 ?g m-2 h-1 in drought 2007, and 266 ± 53 ?g m-2 h-1 in wet 2008, respectively. Warming decreased the standard emission factor (SEF) by 24% in 2007, while it increased by 43% in 2008. The exacerbated soil moisture loss caused by warming in dry season might be responsible for the decrease of SEF in 2007. A possible threshold of soil moisture (8.2% (v/v)), which controls the direction of warming effects on monoterpene emission, existed in the semiarid grassland. Nitrogen deposition decreased the coverage of Artemisia frigida and hence reduced the NER by 24% across the two growing seasons. These results suggest that the grasslands dominated by the extended Artemisia frigida are an important source for BVOCs, while the responses of their emissions to global changes are more uncertain since they depend on multifactorial in-situ conditions.

Wang, H. J.; Xia, J. Y.; Mu, Y. J.; Nie, L.; Han, X. G.; Wan, S. Q.

2012-04-01

362

BVOCs emission in a semi-arid grassland under climate warming and nitrogen deposition  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOCs) profoundly affect atmospheric chemistry and ecosystem functioning. BVOCs emission and their responses to global change are still unclear in grasslands, which cover one quarter of the Earth's land surface and are currently undergoing the largest changes. Over two growing seasons, we conducted a field experiment in a semi-arid grassland (Inner Mongolia, China) to examine the emission and the responses of BVOCs emissions to warming and nitrogen deposition. The natural emission rate (NER) of monoterpene (dominant BVOCs here) is 107 ± 16 ?g m-2 h-1 in drought 2007, and 266 ± 53 ?g m-2 h-1 in wet 2008, respectively. Warming decreased the standard emission factor (SEF) by 24% in 2007, while increased it by 43% in 2008. The exacerbated soil moisture loss caused by warming in dry season might be responsible for the decrease of SEF in 2007. A possible threshold of soil moisture (8.2% (v/v)), which controls the direction of warming effects on monoterpene emission, existed in the semiarid grassland. Nitrogen deposition decreased the coverage of Artemisia frigida and hence reduced the NER by 24% across the two growing seasons. These results suggest that the grasslands dominated by the extended Artemisia frigida are an important source for BVOCs, while the responses of their emissions to global changes are more uncertain since they depend on multifactorial/in-situ/conditions.

Wang, H. J.; Xia, J. Y.; Mu, Y. J.; Nie, L.; Han, X. G.; Wan, S. Q.

2012-01-01

363

Simulated Fish Habitat Changes in North American Lakes in Response to Projected Climate Warming  

Microsoft Academic Search

Fish habitat is strongly constrained by water temperature and the available dissolved oxygen (DO). Fish habitat in small lakes of the contiguous United States was therefore determined from simulated daily water temperature and dissolved oxygen profiles. Twenty-seven types of lakes were simulated under past (1962–1979) climate conditions and a projected doubling of atmospheric carbon dioxide (2×CO2 climate scenario) at 209

Heinz G. Stefan; Xing Fang; John G. Eaton

2001-01-01

364

6146 JOURNAL OF CLIMATE VOLUME 24 Response of the Indian Ocean Basin Mode and Its Capacitor Effect to Global Warming*  

E-print Network

The development of the Indian Ocean basin (IOB) mode and its change under global warming are investigated using a pair of integrations with the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (CM2.1). In the simulation under constant climate forcing, the El Niño–induced warming over the tropical Indian Ocean (TIO) and its capacitor effect on summer northwest Pacific climate are reproduced realistically. In the simulation forced by increased greenhouse gas concentrations, the IOB mode and its summer capacitor effect are enhanced in persistence following El Niño, even though the ENSO itself weakens in response to global warming. In the prior spring, an antisymmetric pattern of rainfall–wind anomalies and the meridional SST gradient across the equator strengthen via increased wind–evaporation–sea surface temperature (WES) feedback. ENSO decays slightly faster in global warming. During the summer following El Niño decay, the resultant decrease in equatorial Pacific SST strengthens the SST contrast with the enhanced TIO warming, increasing the sea level pressure gradient and intensifying the anomalous anticyclone over the northwest Pacific. The easterly wind anomalies associated with the northwest Pacific anticyclone in turn sustain the SST warming over the north Indian Ocean and South China Sea. Thus, the increased TIO capacitor effect is due to enhanced air–sea interaction over the TIO and with the western Pacific. The implications for the observed intensification of the IOB mode and its capacitor effect after the 1970s are discussed. 1.

Xiao-tong Zheng; Shang-ping Xie; Qinyu Liu

2010-01-01

365

Climate hotspots: key vulnerable regions, climate change and limits to warming  

Microsoft Academic Search

Defining and operationalizing Article 2 of the UNFCCC remains a challenge. The question of what is dangerous climate change\\u000a is not a purely scientific one, as danger necessarily has a subjective dimension and its definition requires judgment and\\u000a precaution. The papers in this special issue of Regional Environmental Change attempt to navigate this problem, by offering\\u000a an overview of the

William L. Hare; Wolfgang Cramer; Michiel Schaeffer; Antonella Battaglini; Carlo C. Jaeger

2011-01-01

366

Is the impact of future climate change on hydro-climatic conditions significant? - A climate change study for an Eastern European catchment area.  

NASA Astrophysics Data System (ADS)

The future change of climatic conditions is, among others, closely linked to future hydrological changes. One important aspect of these issues is the question of future availability of water resources. A changed climatic water balance, as indicator for potential water availability, has far-reaching consequences for the water cycle, hydrological conditions, ecology, water management, the energy business, agriculture and forestry, and for anthropogenic use of the river. We generated regional climate projections via dynamic downscaling for the catchment area of the Western Bug river in the border area of Poland, Belarus, and Ukraine. The hydro-climatic conditions of the past and their projected future changes in the catchment were analyzed based on 2m-temperature, precipitation, potential evaporation and climatic water balance. Up to the end of the century, the used IPCC scenarios B1 and A2 lead to warming for each month in the long-term mean, with highest warming rates in winter. Instead, precipitation does not change in the long-term yearly mean. However, the intra-annual distribution of monthly precipitation sums shifts with an increase in winter and a strong decrease in summer. Combined, this leads to a changed climatic water balance with a stronger deficit in summer and a higher gain in winter. Particular in the south-eastern part of the catchment, the summer deficit cannot be compensated within the annual cycle. It raised the question: are these changes statistically significant and thus robust for use in further impact studies? Using a significance analysis, we found, that climatic changes in temperature, precipitation and potential evaporation and thus the climatic water balance change is most significant for scenario A2 from 2071 to 2100. The temperature changes are significant throughout the year. For the other variables changes are most significant in the late summer months (July, August, and September) and the winter months (December, January, and February). In contrast, projected changes are hardly significant in the first period from 2021 to 2050. Only temperatures show most statistically significant changes. Weaker change signals in temperature, precipitation and potential evaporation lead also to weak climatic water balance changes in the first period. However, the projected changes in the first period are already indications of impending climatic changes in the catchment.

Pavlik, Dirk; Söhl, Dennis; Bernhofer, Christian

2014-05-01

367

Thermokarst processes in west-European loess series: new evidences for rapid climatic warming events during the Last Glacial  

NASA Astrophysics Data System (ADS)

For a long time, the imprint of millennial climatic cycles (D/O cycles) in the Last Glacial loess sequences has been related to the alternation of loess layers and arctic brown soil horizons, especially between about 60 and 30 ka BP (± MIS 3). Nevertheless, owing to erosion gaps and strong reductions in the sedimentation rate, there are always less individual soil horizons than D/O cycles during the same period, which makes correlations very difficult. The discovery in the Nussloch loess sequence (Germany) of a thermokarst structure including well preserved vegetal remains, mollusc shells, and relicts of former ice wedge casts, provides new evidences for a rapid climatic warming at the origin of a major erosion event during the Middle Pleniglacial (±MIS 3). This elongated thermokarst erosion gully incised the underlying deposits. The presence of deformed ice-wedge relicts along its very sharp and irregular lower boundary indicates a formation by thermal erosion linked to a rapid melting of the permafrost ice. The analysis of the biological data (vegetal remains and mollusc shells) allows to evidence interstadial conditions strongly contrasting with the over- and underlying loess environments. Radiocarbon dates from wood remains (average 32.26 14C / ± 37.7 cal. BP) allow the correlation of the main thermokarst formation and infilling with GIS-8 from the GRIP ice core, following H4 event. Similar structures have been evidenced in other west-European loess sequences, most of them at the base of the Middle Pleniglacial formations. On the basis of a comparison with present day analogues from Alaska and Siberia permafrost areas, past "thermokarst events" are related to thermal erosion processes and proposed as markers for rapid warming periods in Last Glacial European loess sequences.

Antoine, Pierre; Moine, Olivier; Didier Rousseau, Denis; Hatté, Christine

2013-04-01

368

Tropical Cyclone Climatology in a Global-Warming Climate as Simulated in a 20 km-Mesh Global Atmospheric Model: Frequency and Wind Intensity Analyses  

Microsoft Academic Search

Possible changes in the tropical cyclones in a future, greenhouse-warmed climate are investigated using a 20 km-mesh, high-resolution, global atmospheric model of MRI\\/JMA, with the analyses focused on the evaluation of the frequency and wind intensity. Two types of 10-year climate experiments are conducted. One is a present-day climate experiment, and the other is a greenhouse-warmed climate experiment, with a

Kazuyoshi OOUCHI; Jun YOSHIMURA; Hiromasa YOSHIMURA; Ryo MIZUTA; Shoji KUSUNOKI; Akira NODA

2006-01-01

369

Diagnosing Warm Frontal Cloud Formation in a GCM: A Novel Approach Using Conditional Subsetting  

NASA Technical Reports Server (NTRS)

This study analyzes characteristics of clouds and vertical motion across extratropical cyclone warm fronts in the NASA Goddard Institute for Space Studies general circulation model. The validity of the modeled clouds is assessed using a combination of satellite observations from CloudSat, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E), and the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. The analysis focuses on developing cyclones, to test the model's ability to generate their initial structure. To begin, the extratropical cyclones and their warm fronts are objectively identified and cyclone-local fields are mapped into a vertical transect centered on the surface warm front. To further isolate specific physics, the cyclones are separated using conditional subsetting based on additional cyclone-local variables, and the differences between the subset means are analyzed. Conditional subsets are created based on 1) the transect clouds and 2) vertical motion; 3) the strength of the temperature gradient along the warm front, as well as the storm-local 4) wind speed and 5) precipitable water (PW). The analysis shows that the model does not generate enough frontal cloud, especially at low altitude. The subsetting results reveal that, compared to the observations, the model exhibits a decoupling between cloud formation at high and low altitudes across warm fronts and a weak sensitivity to moisture. These issues are caused in part by the parameterized convection and assumptions in the stratiform cloud scheme that are valid in the subtropics. On the other hand, the model generates proper covariability of low-altitude vertical motion and cloud at the warm front and a joint dependence of cloudiness on wind and PW.

Booth, James F.; Naud, Catherine M.; DelGenio, Anthony D.

2013-01-01

370

The palaeoclimatic significance of Eurasian Giant Salamanders (Cryptobranchidae: Zaissanurus, Andrias) - indications for elevated humidity in Central Asia during global warm periods (Eocene, late Oligocene warming, Miocene Climate Optimum)  

NASA Astrophysics Data System (ADS)

Cryptobranchids represent a group of large sized (up to 1.8 m) tailed amphibians known since the Middle Jurassic (Gao & Shubin 2003). Two species are living today in eastern Eurasia: Andrias davidianus (China) and A. japonicus (Japan). Cenozoic Eurasian fossil giant salamanders are known with two genera and two or three species from over 30 localities, ranging from the Late Eocene to the Early Pliocene (Böhme & Ilg 2003). The Late Eocene species Zaissanurus beliajevae is restricted to the Central Asian Zaissan Basin (SE-Kazakhstan, 50°N, 85°E), whereas the Late Oligocene to Early Pliocene species Andrias scheuchzeri is distributed from Central Europe to the Zaissan Basin. In the latter basin the species occur during two periods; the latest Oligocene and the late Early to early Middle Miocene (Chkhikvadse 1982). Andrias scheuchzeri is osteological indistinguishable from both recent species, indicating a similar ecology (Westfahl 1958). To investigate the palaeoclimatic significance of giant salamanders we analyzed the climate within the present-day distribution area and at selected fossil localities with independent palaeoclimate record. Our results indicate that fossil and recent Andrias species occur in humid areas where the mean annual precipitation reach over 900 mm (900 - 1.300 mm). As a working hypothesis (assuming a similar ecology of Andrias and Zaissanurus) we interpret occurrences of both fossil Eurasian giant salamanders as indicative for humid palaeoclimatic conditions. Based on this assumption the Late Eocene, the latest Oligocene (late Oligocene warming) and the late Early to early Middle Miocene (Miocene Climatic Optimum) of Central Asia (Zaissan Basin) are periods of elevated humidity, suggesting a direct (positive) relationship between global climate and Central Asian humidity evolution. Böhme M., Ilg A. 2003: fosFARbase, www.wahre-staerke.com/ Chkhikvadze V.M. 1982. On the finding of fossil Cryptobranchidae in the USSR and Mongolia. Vertebrata Hungarica, 21: 63-67. Gao K.-Q., Shubin N.H. 2003. Earliest known crown-group Salamanders. Nature, 422: 424-428. Westphal F. 1958. Die Tertiären und rezenten Eurasiatischen Riesensalamander. Palaeontolographica Abt. A, 110: 20-92.

Vasilyan, Davit; Böhme, Madelaine; Winklhofer, Michael

2010-05-01

371

Forest Dynamics and Their Phenological Response to Climate Warming in the Khingan Mountains, Northeastern China  

PubMed Central

The Khingan Mountain region, the most important and typical natural foci of tick-borne encephalitis (TBE) in China, is the largest and northernmost forest area and the one more sensitive to climate change. Taking this region as the study area, we investigated the spatio-temporal dynamics of deciduous broadleaf forest (DBF) and its phenology changes in relation to climate change and elevation. Based on MODIS Enhanced Vegetation Index (EVI) time series over the period of 2001 to 2009, the start-of-season (SOS), length-of-season (LOS) and another two vegetation variables (seasonal amplitude (SA) and integrated EVI (SI)) were derived. Over the past decade, the DBF in Khingan Mountains has generally degraded and over 65% of DBF has experienced negative SA and SI trends. Earlier trends in SOS and longer trends in LOS for DBF were observed, and these trends were mainly caused by climate warming. In addition, results from our analysis also indicated that the effects of temperature on DBF phenology were elevation dependent. The magnitude of advancement in SOS and extension in LOS with temperature increase significantly increased along a raising elevation gradient. PMID:23202825

Cai, Hongyan; Zhang, Shuwen; Yang, Xiaohuan

2012-01-01

372

Direct Expansion Air Conditioning System Selection for Hot & Humid Climates  

E-print Network

This paper discusses some of the difficulties of selecting direct expansion (DX) air conditioning systems to dehumidify conditioned spaces in hot & humid climates. It is a common opinion among designers that concerns of humidity control are best...

Browning, B. K.

2002-01-01

373

Altitudinal and latitudinal dependence of future warming in an island of multi climate zones: Taiwan as an example  

NASA Astrophysics Data System (ADS)

In this study, a global model, ECHAM5, and a mesoscale regional model, Weather Research Forecasting (WRF) were combined to perform dynamic downscaling of Taiwan's climate in the recent past (1979-2003) and climate change projection of near and distant future (2015-2039 and 2075-2099, respectively). Simulation results showed close correlation between fine-resolution downscaling by ECHAM5-WRF and the actual observation data for the period 1979-2003. Projection of future climate changes revealed both altitudinal and latitudinal variations in warming trend, with more significant temperature increase in mountain areas than in plain areas toward the end of the 21st century and more obvious warming in the north than in the south of Taiwan. These findings have essential implications on climate impact issues such as mountain ecology and disease transmission. The results obtained in this study can be applied to other regions of similar latitudes and with comparable relief.

Lin, Chuan-yao; Chua, Ying-Jea; sheng, Yang-Fan; Hsu, Huang-Hsiung; Cheng, Chao-Tzuen; Lin, Yi-Yin

2014-05-01

374

CO2 radiative forcing and Intertropical Convergence Zone influences on western Pacific warm pool climate over the past 400 ka  

NASA Astrophysics Data System (ADS)

The western Pacific warm pool (WPWP) is an important heat source for the atmospheric circulation and influences climate conditions worldwide. Estimating WPWP sensitivity to past radiative forcing perturbations is important for understanding the magnitudes and patterns of current and projected tropical climate change. Here we present a new Mg/Ca-based sea surface temperature (SST) reconstruction over the past 400 ka from the Bismarck Sea, off Papua New Guinea, along with benthic foraminiferal ?18O records and a transient intermediate complexity earth system model simulation. The Mg/Ca-SST record exhibits a close similarity with atmospheric CO2 content for the whole study period. Our model analysis demonstrates that greenhouse gas forcing is the primary driver for glacial/interglacial SST changes in the entire WPWP region. Mg/Ca-SST in the Bismarck Sea also includes a weaker precessional component, which covaries with reconstructed and simulated local precipitation, and simulated surface currents. We propose that orbitally driven latitudinal shifts of the Intertropical Convergence Zone and oceanic heat advection are responsible for this residual SST variability. On glacial timescales the reconstructed WPWP surface temperature changes over the past 400 ka are highly correlated with East Antarctic air temperature variations. The strong effect of greenhouse gas forcings on both records and on global mean temperature variability allows us to determine a scaling factor of 1-1.5 between reconstructed WPWP temperature anomalies and estimates of the global mean temperature.

Tachikawa, Kazuyo; Timmermann, Axel; Vidal, Laurence; Sonzogni, Corinne; Timm, Oliver Elison

2014-02-01

375

Responses of the Kuroshio and the Kuroshio Extension to global warming in a high-resolution climate model  

Microsoft Academic Search

Using a high-resolution atmosphere–ocean coupled climate model, responses of the Kuroshio and the Kuroshio Extension (KE) to global warming are investigated. In a climate change experiment with atmospheric CO2 concentration ideally increased by 1% year?1, the current velocity of the Kuroshio and KE increases, while the latitude of the Kuroshio separation to the east of Japan does not change significantly.

Takashi T. Sakamoto; Hiroyasu Hasumi; Masayoshi Ishii; Seita Emori; Tatsuo Suzuki; Teruyuki Nishimura; Akimasa Sumi

2005-01-01

376

Response of River Runoff in the Cryolithic Zone of Eastern Siberia (Lena River Basin) to Future Climate Warming  

Microsoft Academic Search

\\u000a During the last several decades significant climate warming has been observed in the permafrost regions of Eastern Siberia.\\u000a Observed environmental changes include increasing air temperature and to a lesser degree precipitation. Changes in regional\\u000a climate are accompanied by changes in river runoff. Seasonal and long-term changes of river runoff in different parts of the\\u000a Lena river basin are characterized by

A. G. Georgiadi; I. P. Milyukova; E. A. Kashutina

377

Can warm climate-related structure of littoral predator assemblies weaken the clear water state in shallow lakes?  

Microsoft Academic Search

Shallow lakes, the most abundant lake type in the world, are very sensitive to climatic changes. The structure and functioning of shallow lakes are greatly impacted by sub- merged plants, and these may be affected by climate warming in various, contrasting, ways. Following a space-for-time substitution approach, we aimed to analyse the role of aquatic (submerged and free-floating) plants in

J UAN; CARLOS I GLESIAS; R. P EDERSEN; Ole Worms

2007-01-01

378

ATM S 211 Climate and Climate Change Prof. David Catling EXAMPLES OF MISINFORMATION FROM GLOBAL WARMING DENIERS  

E-print Network

in great detail in the IPCC report. The IPCC consensus concluded: - There was a global warming trend warming. Kuwaiti Foundation funded Balling's skeptic book on global warming. Prof. Richard Lindzen (MIT) Mostly has his own scientific reasons for "opposing" global warming. But 1991 trip to Senate hearings

Catling, David C.

379

Climatic conditions cause complex patterns of covariation between demographic traits in a long-lived raptor.  

PubMed

Environmental variation can induce life-history changes that can last over a large part of the lifetime of an organism. If multiple demographic traits are affected, expected changes in climate may influence environmental covariances among traits in a complex manner. Thus, examining the consequences of environmental fluctuations requires that individual information at multiple life stages is available, which is particularly challenging in long-lived species. Here, we analyse how variation in climatic conditions occurring in the year of hatching of female goshawks Accipiter gentilis (L.) affects age-specific variation in demographic traits and lifetime reproductive success (LRS). LRS decreased with increasing temperature in April in the year of hatching, due to lower breeding frequency and shorter reproductive life span. In contrast, the probability for a female to successfully breed was higher in years with a warm April, but lower LRS of the offspring in these years generated a negative covariance among fecundity rates among generations. The mechanism by which climatic conditions generated cohort effects was likely through influencing the quality of the breeding segment of the population in a given year, as the proportion of pigeons in the diet during the breeding period was positively related to annual and LRS, and the diet of adult females that hatched in warm years contained fewer pigeons. Climatic conditions experienced during different stages of individual life histories caused complex patterns of environmental covariance among demographic traits even across generations. Such environmental covariances may either buffer or amplify impacts of climate change on population growth, emphasizing the importance of considering demographic changes during the complete life history of individuals when predicting the effect of climatic change on population dynamics of long-lived species. PMID:25403010

Herfindal, Ivar; van de Pol, Martijn; Nielsen, Jan T; Saether, Bernt-Erik; Møller, Anders P

2014-11-17

380

Stand Competition Determines How Different Tree Species Will Cope with a Warming Climate  

PubMed Central

Plant-plant interactions influence how forests cope with climate and contribute to modulate species response to future climate scenarios. We analysed the functional relationships between growth, climate and competition for Pinus sylvestris, Quercus pyrenaica and Quercus faginea to investigate how stand competition modifies forest sensitivity to climate and simulated how annual growth rates of these species with different drought tolerance would change throughout the 21st century. Dendroecological data from stands subjected to thinning were modelled using a novel multiplicative nonlinear approach to overcome biases related to the general assumption of a linear relationship between covariates and to better mimic the biological relationships involved. Growth always decreased exponentially with increasing competition, which explained more growth variability than climate in Q. faginea and P. sylvestris. The effect of precipitation was asymptotic in all cases, while the relationship between growth and temperature reached an optimum after which growth declined with warmer temperatures. Our growth projections indicate that the less drought-tolerant P. sylvestris would be more negatively affected by climate change than the studied sub-Mediterranean oaks. Q. faginea and P. sylvestris mean growth would decrease under all the climate change scenarios assessed. However, P. sylvestris growth would decline regardless of the competition level, whereas this decrease would be offset by reduced competition in Q. faginea. Conversely, Q. pyrenaica growth would remain similar to current rates, except for the warmest scenario. Our models shed light on the nature of the species-specific interaction between climate and competition and yield important implications for management. Assuming that individual growth is directly related to tree performance, trees under low competition would better withstand the warmer conditions predicted under climate change scenarios but in a variable manner depending on the species. Thinning following an exponential rule may be desirable to ensure long-term conservation of high-density Mediterranean woodlands, particularly in drought-limited sites. PMID:25826446

Fernández-de-Uña, Laura; Cañellas, Isabel; Gea-Izquierdo, Guillermo

2015-01-01

381

Climatic limits of pink bollworm in Arizona and California: effects of climate warming  

NASA Astrophysics Data System (ADS)

The distribution and abundance of pink bollworm ( Pectinophora gossypiella Saunders ( PBW)) in cotton in Arizona and California was examined using a validated weather-driven, physiologically based demographic model of cotton and PBW integrated into a geographic information system (GIS). Survival of diapause larvae during winter as affected by low temperatures is a key factor determining the range of PBW. Winter survival was estimated using data from Gutierrez et al. (Can. Entomol. 109 (1977) 1457) and Venette et al. (Environ. Entomol. 29 (5) (2000) 1018). The model was run continuously over the period 1 January 1995 to 31 December 2003 using observed weather data from 121 locations. Three output variables were mapped as measures of PBW persistence: over-winter survival of diapause PBW larvae, cumulative daily PBW larval densities over the season, and the number of diapause larvae produced during the season. The distribution of pink bollworm is predicted to be restricted to the relatively frost-free cotton growing areas of Arizona and Southern California where it currently reaches pest status. The model predicts that extension of PBW's range into the Central Valley of California is unlikely. The analysis questions the efficacy of an ongoing area-wide effort to prevent the establishment of PBW in the Central Valley of California. Four global warming scenarios were examined to estimate the effects on the potential geographic range of PBW. Average observed daily temperatures were increased 1.0, 1.5, 2.0 or 2.5 °C, respectively, in the four scenarios. Scenarios with average increases of 1.5-2.5 °C predicted that the range of PBW would expand into the Central Valley of California and the severity of the pest would greatly increase in areas of current infestation.

Gutierrez, Andrew Paul; D'Oultremont, Thibaud; Ellis, C. K.; Ponti, Luigi

2006-11-01

382

International potential of IGCC technology for use in reducing global warming and climate change emissions  

SciTech Connect

High efficiency advanced coal-based technologies such as Integrated Gasification Combined Cycle (IGCC) that can assist in reducing CO{sub 2} emissions which contribute to Global Warming and Climate Change are becoming commercially available. U-GAS is an advanced gasification technology that can be used in many applications to convert coal in a high efficiency manner that will reduce the total amount of CO{sub 2} produced by requiring less coal-based fuel per unit of energy output. This paper will focus on the status of the installation and performance of the IGT U-GAS gasifiers which were installed at the Shanghai Cooking and Chemical Plant General located in Shanghai, China. Its use in future IGCC project for the production of power and the benefits of IGCC in reducing CO{sub 2} emissions through its high efficiency operation will be discussed.

Lau, F.S. [Inst. of Gas Technology, Chicago, IL (United States)

1996-12-31

383

Biotic Response in Aquatic Reptiles (Testudines) during Earliest Eocene Climatic Warming  

NASA Astrophysics Data System (ADS)

The earliest Eocene is marked by significant events of global warming: the Paleocene-Eocene Thermal Maximum (PETM) at ~55.8 Ma and two short-lived events (ETM2 or Elmo and H2) approximately 2 Ma later. These environmental changes induced strong responses in the continental biota. Noteworthy changes in North American mid-latitude faunas and floras that are temporally correlated with earliest Eocene warming events include: increased diversity; turnover; and significant range changes, comprising both northward shifts in ranges of North American taxa as well as intercontinental dispersal across Holarctica. Evidence for these biotic changes comes directly from the fossil record and indirectly from phylogeographic analyses of molecular phylogenies of extant biota. To date, the stratigraphic record of biotic change has only been examined for the flora and terrestrial mammals. Data on reptiles and for continental aquatic systems are particularly lacking. In order to assess the impact of climate-mediated faunal change in aquatic systems during early Paleogene warming, we have focused on developing a detailed record of fossil turtles (Testudines) from the Bighorn Basin of Wyoming, where these records can be directly compared to similarly studied mammalian and floral data and to isotopic studies that provide independent proxies of climate change. Using genus-level occurrence data from more than 450 stratigraphically-constrained localities spanning ~2.5 Ma, we calculated first and last appearances, taxonomic richness, and relative abundance as measured by presence-absence (site occupancy). Among turtles, taxonomic richness increased episodically through the earliest Eocene with two new taxa appearing at the PETM, two immediately following it, and two at Biohorizon B, an interval associated with the younger hyperthermals. These new, immigrant taxa eventually comprised 40% of known generic richness. Phylogenetically, the inferred biogeographic source regions are southern North America and Asia, with an equal number of taxa originating in each area. Although immigrant taxa comprised less than half of the known earliest Eocene diversity, their relative dominance in these assemblages varied markedly. Within the PETM interval, immigrant taxa comprise nearly 70% of occurrences. Post-PETM, as temperatures cooled, immigrant taxa and taxa persisting from the Paleocene showed greater evenness, but immigrant taxa again became dominant with renewed warming. Among immigrant taxa, intercontinental dispersers are much more common than those that that dispersed from southern North America. These data are consistent with and stratigraphically correlative with significant changes in the mammalian fauna and flora of the Bighorn Basin and underline the importance of climatic change as a driver in these events. However, the magnitude and relative importance of intra- vs. intercontinental dispersal has not yet been fully examined in other taxonomic groups. The asymmetry of response following immigration that we observe in turtles may be taxon-specific, unique to aquatic systems, or may illustrate a more general pattern of how biotas respond to significant climate change.

Holroyd, P. A.; Hutchison, J. H.

2010-12-01

384

Positive feedback between global warming and atmospheric CO2 concentration inferred from past climate change  

NASA Astrophysics Data System (ADS)

There is good evidence that higher global temperatures will promote a rise of greenhouse gas levels, implying a positive feedback which will increase the effect of anthropogenic emissions on global temperatures. However, the magnitude of this effect predicted by the available models remains highly uncertain, due to the accumulation of uncertainties in the processes thought to be involved. Here we present an alternative way of estimating the magnitude of the feedback effect based on reconstructed past changes. Linking this information with the mid-range Intergovernmental Panel on Climate Change estimation of the greenhouse gas effect on temperature we suggest that the feedback of global temperature on atmospheric CO2 will promote warming by an extra 15-78% on a century-scale. This estimate may be conservative as we did not account for synergistic effects of likely temperature moderated increase in other greenhouse gases. Our semi-empirical approach independently supports process based simulations suggesting that feedback may cause a considerable boost in warming.

Scheffer, Marten; Brovkin, Victor; Cox, Peter M.

2006-05-01

385

Early Paleogene Arctic terrestrial ecosystems affected by the change of polar hydrology under global warming: Implications for modern climate change at high latitudes  

Microsoft Academic Search

Our understanding of both the role and impact of Arctic environmental changes under the current global warming climate is\\u000a rather limited despite efforts of improved monitoring and wider assessment through remote sensing technology. Changes of Arctic\\u000a ecosystems under early Paleogene warming climate provide an analogue to evaluate long-term responses of Arctic environmental\\u000a alteration to global warming. This study reviews Arctic

Qin Leng; Gaytha A. Langlois; Hong Yang

2010-01-01

386

Rapid Carbon Accumulation Associated With Warm Medieval Climate in Peatlands of a Glaciated Valley in Southcentral Alaska  

NASA Astrophysics Data System (ADS)

Peatlands are among the largest reservoirs of terrestrial carbon (C) in the northern hemisphere. Understanding how this carbon pool will respond to climate changes is critical to assessing potential earth-system feedbacks. Peatland C accumulation is controlled by the relative rates of production and decomposition, and the rate of these processes is affected by many factors, including temperature, hydrology, and vegetation. In order to better understand the potential influences of past climate change on C accumulation, we developed a coupled study of peatland paleohydrology and C accumulation from a Sphagnum-dominated peatland located in a glaciated valley south of the Alaska Range in southcentral Alaska. Past responses of this peatland to well-documented climate and temperature changes, like the Medieval Climate Anomaly (MCA) at 1000-600 cal yr BP and Little Ice Age (LIA) at 600-100 cal yr BP, were investigated using water-table depths inferred from testate amoebae and C accumulation rates calculated from loss-on-ignition and 14C-dating analyses. Although warmer temperatures, like those experienced in Alaska during the MCA, might be expected to result in lower water tables and reduced C accumulation, our results indicate that the peatland C accumulation rate during the MCA (~150 gC/m2/yr) was about three times greater than during the LIA (~50 gC/m2/yr). Also, reconstructed water-table depths indicate relatively wet conditions on the peatland during the MCA, suggesting that this region may have experienced increased precipitation during this time, or increased melting of glaciers. Although glacier meltwater was not hydrologically connected to the peatland, it may have led to greater relative humidity that mediated potential drying associated with warmer temperatures. We found that the average ash-free bulk density values during the MCA (0.128 g/cm3) were lower than the average values during the LIA (0.172 g/cm3), consistent with our reconstructed water-table depths. Furthermore, our data show that C accumulation rates during the post-LIA recent warming have been similar to those experienced during the MCA. This study implies that some northern peatlands could serve as a negative feedback to climate change by sequestering more C as temperatures increase, given sufficient moisture conditions are maintained through increased precipitation or by other hydrological changes, such as those from receding glaciers.

Klein, E. S.; Booth, R. K.; Yu, Z.

2010-12-01

387

Possible Effects of Climate Warming on Selected Populations of Polar Bears (Ursus maritimus) in the Canadian Arctic  

Microsoft Academic Search

Polar bears depend on sea ice for survival. Climate warming in the Arctic has caused significant declines in total cover and thickness of sea ice in the polar basin and progressively earlier breakup in some areas. Inuit hunters in the areas of four polar bear populations in the eastern Canadian Arctic (including Western Hudson Bay) have reported seeing more bears

IAN STIRLING; CLAIRE L. PARKINSON

2006-01-01

388

Evaluating indicators for the relative responsibility for climate change - alternatives to the Brazilian proposal and global warming potentials  

Microsoft Academic Search

In this paper, several indicators to describe the responsibility for climate change are discussed and evaluated. During the negotiations of the Kyoto Protocol, the delegation of Brazil proposed to use the impact of historical emissions on the current temperature. The Kyoto Protocol uses current emissions weighted by 100-year global warming potentials (GWPs) as the basis. As a powerful indicator historical

N. Höhne; J. Harnisch

2002-01-01

389

The role of meltwater-induced subsurface ocean warming in regulating the Atlantic meridional overturning in glacial climate simulations  

Microsoft Academic Search

The Community Climate System Model version 3, (CCSM3) is used to investigate the effect of the high latitude North Atlantic subsurface ocean temperature response in idealized freshwater hosing experiments on the strength of the Atlantic meridional overturning circulation (AMOC). The hosing experiments covered a range of input magnitudes at two locations in a glacial background state. Subsurface subpolar ocean warms

Esther C. Brady; Bette L. Otto-Bliesner

2011-01-01

390

The role of meltwater-induced subsurface ocean warming in regulating the Atlantic meridional overturning in glacial climate simulations  

Microsoft Academic Search

The Community Climate System Model version 3, (CCSM3) is used to investigate the effect of the high latitude North Atlantic subsurface ocean temperature response in idealized freshwater hosing experiments on the strength of the Atlantic meridional overturning circulation (AMOC). The hosing experiments covered a range of input magnitudes at two locations in a glacial background state. Subsurface subpolar ocean warms

Esther C. Brady; Bette L. Otto-Bliesner

2010-01-01

391

Vegetation limits the impact of a warm climate on boreal wildfires.  

PubMed

Strategic introduction of less flammable broadleaf vegetation into landscapes was suggested as a management strategy for decreasing the risk of boreal wildfires projected under climatic change. However, the realization and strength of this offsetting effect in an actual environment remain to be demonstrated. Here we combined paleoecological data, global climate models and wildfire modelling to assess regional fire frequency (RegFF, i.e. the number of fires through time) in boreal forests as it relates to tree species composition and climate over millennial time-scales. Lacustrine charcoals from northern landscapes of eastern boreal Canada indicate that RegFF during the mid-Holocene (6000-3000 yr ago) was significantly higher than pre-industrial RegFF (AD c. 1750). In southern landscapes, RegFF was not significantly higher than the pre-industrial RegFF in spite of the declining drought severity. The modelling experiment indicates that the high fire risk brought about by a warmer and drier climate in the south during the mid-Holocene was offset by a higher broadleaf component. Our data highlight an important function for broadleaf vegetation in determining boreal RegFF in a warmer climate. We estimate that its feedback may be large enough to offset the projected climate change impacts on drought conditions. PMID:23691916

Girardin, Martin P; Ali, Adam A; Carcaillet, Christopher; Blarquez, Olivier; Hély, Christelle; Terrier, Aurélie; Genries, Aurélie; Bergeron, Yves

2013-09-01

392

Global warming and climate change - predictive models for temperate and tropical regions  

SciTech Connect

Based on the assumption of 4{degree}C increase of global temperature by the turn of 21st century due to the accumulation of greenhouse gases an attempt is made to study the possible variations in different climatic regimes. The predictive climatic water balance model for Hokkaido island of Japan (a temperate zone) indicates the possible occurrence of water deficit for two to three months, which is a unknown phenomenon in this region at present. Similarly, India which represents tropical region also will experience much drier climates with increased water deficit conditions. As a consequence, the thermal region of Hokkaido which at present is mostly Tundra and Micro thermal will change into a Meso thermal category. Similarly, the moisture regime which at present supports per humid (A2, A3 and A4) and Humid (B4) climates can support A1, B4, B3, B2 and B1 climates indicating a shift towards drier side of the climatic spectrum. Further, the predictive modes of both the regions have indicated increased evapotranspiration rates. Although there is not much of change in the overall thermal characteristics of the Indian region the moisture regime indicates a clear shift towards the aridity in the country.

Malini, B.H. [Andhra Univ., Visakhapatnam (India)

1997-12-31

393

Extreme climatic events and their evolution under changing climatic conditions  

E-print Network

of instant media attention that serves to emphasize the catastrophic nature of floods, droughts, storms (tropical cyclones and mid- latitude winter storms), floods, droughts and heat waves. The earthquake events to extreme climatic events and the possible shifts in frequency and intensity of storms, floods, and heat

Stephenson, David B.

394

Projected climate regime shift under future global warming from multi-model, multi-scenario CMIP5 simulations  

NASA Astrophysics Data System (ADS)

This study examined shifts in climate regimes over the global land area using the Köppen-Trewartha (K-T) climate classification by analyzing observations during 1900-2010, and simulations during 1900-2100 from twenty global climate models participating in Phase 5 of the Coupled Model Inter-comparison Project (CMIP5). Under the Intergovernmental Panel on Climate Change Representative Concentration Pathways 8.5 (RCP8.5) scenario, the models projected a 3°-10 °C warming in annual temperature over the global land area by the end of the twenty-first century, with strong (moderate) warming in the high (middle) latitudes of the Northern Hemisphere and weaker warming in the tropics and the Southern Hemisphere. The projected changes in precipitation vary considerably in space and present greater uncertainties among the models. Overall, the models are consistent in projecting increasing precipitation over the high-latitude of the Northern Hemisphere, and reduced precipitation in the Mediterranean, southwestern North America, northern and southern Africa and Australia. Based on the projected changes in temperature and precipitation, the K-T climate types would shift toward warmer and drier climate types from the current climate distribution. Regions of temperate, tropical and dry climate types are projected to expand, while regions of polar, sub-polar and subtropical climate types are projected to contract. The magnitudes of the projected changes are stronger in the RCP8.5 scenario than the low emission scenario RCP4.5. On average, the climate types in 31.4% and 46.3% of the global land area are projected to change by the end of the twenty-first century under RCP4.5 and RCP8.5 scenarios, respectively. Further analysis suggests that changes in precipitation played a slightly more important role in causing shifts of climate type during the twentieth century. However, the projected changes in temperature play an increasingly important role and dominate shifts in climate type when the warming becomes more pronounced in the twenty-first century.

Feng, Song; Hu, Qi; Huang, Wei; Ho, Chang-Hoi; Li, Ruopu; Tang, Zhenghong

2014-01-01

395

Short- and long-term conditioning of a temperate marine diatom community to acidification and warming.  

PubMed

Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated pCO2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and pCO2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into 'artificial' communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned 'artificial' community experiments was similar, despite differences such as the loss of two species in the latter. pCO2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes. PMID:23980240

Tatters, Avery O; Roleda, Michael Y; Schnetzer, Astrid; Fu, Feixue; Hurd, Catriona L; Boyd, Philip W; Caron, David A; Lie, Alle A Y; Hoffmann, Linn J; Hutchins, David A

2013-01-01

396

Short- and long-term conditioning of a temperate marine diatom community to acidification and warming  

PubMed Central

Ocean acidification and greenhouse warming will interactively influence competitive success of key phytoplankton groups such as diatoms, but how long-term responses to global change will affect community structure is unknown. We incubated a mixed natural diatom community from coastal New Zealand waters in a short-term (two-week) incubation experiment using a factorial matrix of warming and/or elevated pCO2 and measured effects on community structure. We then isolated the dominant diatoms in clonal cultures and conditioned them for 1 year under the same temperature and pCO2 conditions from which they were isolated, in order to allow for extended selection or acclimation by these abiotic environmental change factors in the absence of interspecific interactions. These conditioned isolates were then recombined into ‘artificial’ communities modelled after the original natural assemblage and allowed to compete under conditions identical to those in the short-term natural community experiment. In general, the resulting structure of both the unconditioned natural community and conditioned ‘artificial’ community experiments was similar, despite differences such as the loss of two species in the latter. pCO2 and temperature had both individual and interactive effects on community structure, but temperature was more influential, as warming significantly reduced species richness. In this case, our short-term manipulative experiment with a mixed natural assemblage spanning weeks served as a reasonable proxy to predict the effects of global change forcing on diatom community structure after the component species were conditioned in isolation over an extended timescale. Future studies will be required to assess whether or not this is also the case for other types of algal communities from other marine regimes. PMID:23980240

Tatters, Avery O.; Roleda, Michael Y.; Schnetzer, Astrid; Fu, Feixue; Hurd, Catriona L.; Boyd, Philip W.; Caron, David A.; Lie, Alle A. Y.; Hoffmann, Linn J.; Hutchins, David A.

2013-01-01

397

Global warming and climate forcing by recent albedo changes on Mars.  

PubMed

For hundreds of years, scientists have tracked the changing appearance of Mars, first by hand drawings and later by photographs. Because of this historical record, many classical albedo patterns have long been known to shift in appearance over time. Decadal variations of the martian surface albedo are generally attributed to removal and deposition of small amounts of relatively bright dust on the surface. Large swaths of the surface (up to 56 million km2) have been observed to darken or brighten by 10 per cent or more. It is unknown, however, how these albedo changes affect wind circulation, dust transport and the feedback between these processes and the martian climate. Here we present predictions from a Mars general circulation model, indicating that the observed interannual albedo alterations strongly influence the martian environment. Results indicate enhanced wind stress in recently darkened areas and decreased wind stress in brightened areas, producing a positive feedback system in which the albedo changes strengthen the winds that generate the changes. The simulations also predict a net annual global warming of surface air temperatures by approximately 0.65 K, enhancing dust lifting by increasing the likelihood of dust devil generation. The increase in global dust lifting by both wind stress and dust devils may affect the mechanisms that trigger large dust storm initiation, a poorly understood phenomenon, unique to Mars. In addition, predicted increases in summertime air temperatures at high southern latitudes would contribute to the rapid and steady scarp retreat that has been observed in the south polar residual ice for the past four Mars years. Our results suggest that documented albedo changes affect recent climate change and large-scale weather patterns on Mars, and thus albedo variations are a necessary component of future atmospheric and climate studies. PMID:17410170

Fenton, Lori K; Geissler, Paul E; Haberle, Robert M

2007-04-01

398

Climate warming decreases the survival of the little auk (Alle alle), a high Arctic avian predator.  

PubMed

Delayed maturity, low fecundity, and high adult survival are traits typical for species with a long-life expectancy. For such species, even a small change in adult survival can strongly affect the population dynamics and viability. We examined the effects of both regional and local climatic variability on adult survival of the little auk, a long-lived and numerous Arctic seabird speci