Heated debate
Daniel Chapman & Brian Lickel
Social Psychological and Personality Science, forthcoming
Abstract:
This research examined whether framing a natural disaster as the product of climate change impacts attitudes toward disaster victims and humanitarian relief. Participants (n = 211) read an article about a famine caused by severe droughts, with one condition attributing the droughts to climate change and the other condition made no mention of climate change. All participants then responded to measures of justifications for or against providing aid, attitudes toward the possibility of donating, and climate change beliefs. As predicted, those high in climate change skepticism reported greater justifications for not helping the victims when the disaster was attributed to climate change. Additional moderated mediation analyses showed there was an indirect effect of climate change framing on attitudes toward donating through donation justifications.
---------------------
Political influences on greenhouse gas emissions from US states
Thomas Dietz et al.
Proceedings of the National Academy of Sciences, 7 July 2015, Pages 8254-8259
Abstract:
Starting at least in the 1970s, empirical work suggested that demographic (population) and economic (affluence) forces are the key drivers of anthropogenic stress on the environment. We evaluate the extent to which politics attenuates the effects of economic and demographic factors on environmental outcomes by examining variation in CO2 emissions across US states and within states over time. We find that demographic and economic forces can in part be offset by politics supportive of the environment — increases in emissions over time are lower in states that elect legislators with strong environmental records.
---------------------
The relationship between climate change concern and national wealth
Alex Lo & Alex Chow
Climatic Change, July 2015, Pages 335-348
Abstract:
Based on a cross-national social survey, this paper ascertains how perception of climate change is related to national wealth and adaptive capacity across 33 countries. Results indicate that citizens of wealthier countries tend to see climate change as the most important problem, but are less likely to rank it as a highly dangerous threat. We find that Gross Domestic Product (GDP) per capita correlates positively with perceived importance of climate change, but negatively with perceived risk. Also, climate change is less likely to be seen as highly dangerous in those countries that are better prepared for climate change. These findings have important implications for climate adaptation. The relatively weaker sense of danger among the wealthiest societies may eventually lead to maladaptation to climate change. Adequate economic resources provide people collective security and protection from impending crises, but could elevate a self-assuring attitude that might prematurely reduce their caution toward the impending threat and capacity for dealing with climate uncertainties.
---------------------
Recent California Water Year Precipitation Deficits: A 440-Year Perspective
Henry Diaz & Eugene Wahl
Journal of Climate, June 2015, Pages 4637–4652
Abstract:
An analysis of the October 2013–September 2014 precipitation in the western United States and in particular over the California–Nevada region suggests this anomalously dry season, while extreme, is not unprecedented in comparison with the approximately 120-yr-long instrumental record of water year (WY; October–September) totals and in comparison with a 407-yr WY precipitation reconstruction dating back to 1571. Over this longer period, nine other years are known or estimated to have been nearly as dry or drier than WY 2014. The 3-yr deficit for WYs 2012–14, which in California exceeded the annual mean precipitation, is more extreme but also not unprecedented, occurring three other times over the past approximate 440 years in the reconstruction. WY precipitation has also been deficient on average for the past 14 years, and such a run of predominantly dry WYs is also a rare occurrence in the authors’ merged reconstructed plus instrumental period record.
---------------------
Fengpeng Sun, Daniel Walton & Alex Hall
Journal of Climate, June 2015, Pages 4618–4636
Abstract:
Using the hybrid downscaling technique developed in part I of this study, temperature changes relative to a baseline period (1981–2000) in the greater Los Angeles region are downscaled for two future time slices: midcentury (2041–60) and end of century (2081–2100). Two representative concentration pathways (RCPs) are considered, corresponding to greenhouse gas emission reductions over coming decades (RCP2.6) and to continued twenty-first-century emissions increases (RCP8.5). All available global climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are downscaled to provide likelihood and uncertainty estimates. By the end of century under RCP8.5, a distinctly new regional climate state emerges: average temperatures will almost certainly be outside the interannual variability range seen in the baseline. Except for the highest elevations and a narrow swath very near the coast, land locations will likely see 60–90 additional extremely hot days per year, effectively adding a new season of extreme heat. In mountainous areas, a majority of the many baseline days with freezing nighttime temperatures will most likely not occur. According to a similarity metric that measures daily temperature variability and the climate change signal, the RCP8.5 end-of-century climate will most likely be only about 50% similar to the baseline. For midcentury under RCP2.6 and RCP8.5 and end of century under RCP2.6, these same measures also indicate a detectable though less significant climatic shift. Therefore, while measures reducing global emissions would not prevent climate change at this regional scale in the coming decades, their impact would be dramatic by the end of the twenty-first century.
---------------------
David Mills et al.
Climatic Change, July 2015, Pages 83-95
Abstract:
This paper applies city-specific mortality relationships for extremely hot and cold temperatures for 33 Metropolitan Statistical Areas in the United States to develop mortality projections for historical and potential future climates. These projections, which cover roughly 100 million of 310 million U.S. residents in 2010, highlight a potential change in health risks from uncontrolled climate change and the potential benefits of a greenhouse gas (GHG) mitigation policy. Our analysis reveals that projected mortality from extremely hot and cold days combined increases significantly over the 21st century because of the overwhelming increase in extremely hot days. We also find that the evaluated GHG mitigation policy could substantially reduce this risk. These results become more pronounced when accounting for projected population changes. These results challenge arguments that there could be a mortality benefit attributable to changes in extreme temperatures from future warming. This finding of a net increase in mortality also holds in an analog city sensitivity analysis that incorporates a strong adaptation assumption. While our results do not address all sources of uncertainty, their scale and scope highlight one component of the potential health risks of unmitigated climate change impacts on extreme temperatures and draw attention to the need to continue to refine analytical tools and methods for this type of analysis.
---------------------
Moral Frames and Climate Change Policy Attitudes
Alexander Severson & Eric Coleman
Social Science Quarterly, forthcoming
Objective: This article compares the effects of various climate change issue frames (deontological-moral, empirical-scientific, and economic) on support for climate change mitigation policies.
Methods: Using an issue-framing survey experiment conducted on Amazon Mechanical Turk, we assess framing effects on climate change policy support using ordinary least squares regression.
Results: We find mixed evidence regarding frame effectiveness. Religious moral frames and economic efficiency frames are ineffective, whereas scientific frames, secular moral frames, and economic equity frames are effective at increasing overall policy support. Additionally, the positive science frame and economic equity frame reduce the ideological divide in climate policy support.
Conclusion: The effects of issue framing on climate policy support are mixed. Frames that we expected conservatives to be responsive to (religious morality; economic efficiency) fail to change support for climate policy. Frames that emphasize science, secular morality, and economy equity have the potential to increase public support for climate change policies.
---------------------
Climate change impacts on extreme events in the United States: An uncertainty analysis
Erwan Monier & Xiang Gao
Climatic Change, July 2015, Pages 67-81
Abstract:
In this study, we analyze changes in extreme temperature and precipitation over the US in a 60-member ensemble simulation of the 21st century with the Massachusetts Institute of Technology (MIT) Integrated Global System Model–Community Atmosphere Model (IGSM-CAM). Four values of climate sensitivity, three emissions scenarios and five initial conditions are considered. The results show a general intensification and an increase in the frequency of extreme hot temperatures and extreme precipitation events over most of the US. Extreme cold temperatures are projected to decrease in intensity and frequency, especially over the northern parts of the US. This study displays a wide range of future changes in extreme events in the US, even simulated by a single climate model. Results clearly show that the choice of policy is the largest source of uncertainty in the magnitude of the changes. The impact of the climate sensitivity is largest for the unconstrained emissions scenario and the implementation of a stabilization scenario drastically reduces the changes in extremes, even for the highest climate sensitivity considered. Finally, simulations with different initial conditions show conspicuously different patterns and magnitudes of changes in extreme events, underlining the role of natural variability in projections of changes in extreme events.
---------------------
Hao Cai et al.
Environmental Science & Technology, 7 July 2015, Pages 8219–8227
Abstract:
Greenhouse gas (GHG) regulations affecting U.S. transportation fuels require holistic examination of the life-cycle emissions of U.S. petroleum feedstocks. With an expanded system boundary that included land disturbance-induced GHG emissions, we estimated well-to-wheels (WTW) GHG emissions of U.S. production of gasoline and diesel sourced from Canadian oil sands. Our analysis was based on detailed characterization of the energy intensities of 27 oil sands projects, representing industrial practices and technological advances since 2008. Four major oil sands production pathways were examined, including bitumen and synthetic crude oil (SCO) from both surface mining and in situ projects. Pathway-average GHG emissions from oil sands extraction, separation, and upgrading ranged from ∼6.1 to ∼27.3 g CO2 equivalents per megajoule (in lower heating value, CO2e/MJ). This range can be compared to ∼4.4 g CO2e/MJ for U.S. conventional crude oil recovery. Depending on the extraction technology and product type output of oil sands projects, the WTW GHG emissions for gasoline and diesel produced from bitumen and SCO in U.S. refineries were in the range of 100–115 and 99–117 g CO2e/MJ, respectively, representing, on average, about 18% and 21% higher emissions than those derived from U.S. conventional crudes. WTW GHG emissions of gasoline and diesel derived from diluted bitumen ranged from 97 to 103 and 96 to 104 g CO2e/MJ, respectively, showing the effect of diluent use on fuel emissions.
---------------------
Increased heat waves with loss of irrigation in the United States
Yaqiong Lu & Lara Kueppers
Environmental Research Letters, June 2015
Abstract:
A potential decline in irrigation due to groundwater depletion or insufficient surface water would not only directly affect agriculture, but also could alter surface climate. In this study we investigated how loss of irrigation affects heat wave frequency, duration, and intensity across fifteen heat wave indices (HINs) using a regional climate model that incorporated dynamic crop growth. Averaged across all indices, loss of irrigation increased heat wave frequency, duration, and intensity. In the United States, irrigation effects on heat waves were statistically significant over irrigated cropland for the majority of HINs, but in non-irrigated regions, the effects were significant only for a few HINs. The heat index temperature metrics that include humidity were less sensitive to loss of irrigation due to the trade-off between increased temperature and decreased humidity. Using the same temperature metric but different temperature thresholds resulted in qualitatively similar effects on heat waves. Regions experiencing strong groundwater depletion, such as the southern high plains, may suffer more and longer heat waves with reduced irrigation.
---------------------
Heat stress causes substantial labour productivity loss in Australia
Kerstin Zander et al.
Nature Climate Change, July 2015, Pages 647–651
Abstract:
Heat stress at the workplace is an occupational health hazard that reduces labour productivity. Assessment of productivity loss resulting from climate change has so far been based on physiological models of heat exposure. These models suggest productivity may decrease by 11–27% by 2080 in hot regions such as Asia and the Caribbean, and globally by up to 20% in hot months by 2050. Using an approach derived from health economics, we describe self-reported estimates of work absenteeism and reductions in work performance caused by heat in Australia during 2013/2014. We found that the annual costs were US$655 per person across a representative sample of 1,726 employed Australians. This represents an annual economic burden of around US$6.2 billion (95% CI: 5.2–7.3 billion) for the Australian workforce. This amounts to 0.33 to 0.47% of Australia’s GDP. Although this was a period when many Australians experienced what is at present considered exceptional heat, our results suggest that adaptation measures to reduce heat effects should be adopted widely if severe economic impacts from labour productivity loss are to be avoided if heat waves become as frequent as predicted.
---------------------
Jacob Samuel Tse Forsyth, Magdalena Andres & Glen Gawarkiewicz
Journal of Geophysical Research: Oceans, March 2015, Pages 2370–2384
Abstract:
Expendable bathythermographs (XBTs) have been launched along a repeat track from New Jersey to Bermuda from the CMV Oleander through the NOAA/NEFSC Ship of Opportunity Program about 14 times per year since 1977. The XBT temperatures on the Middle Atlantic Bight shelf are binned with 10 km horizontal and 5 m vertical resolution to produce monthly, seasonally, and annually averaged cross-shelf temperature sections. The depth-averaged shelf temperature, Ts, calculated from annually averaged sections that are spatially averaged across the shelf, increases at 0.026 ± 0.001°C yr−1 from 1977 to 2013, with the recent trend substantially larger than the overall 37 year trend (0.11 ± 0.02°C yr−1 since 2002). The Oleander temperature sections suggest that the recent acceleration in warming on the shelf is not confined to the surface, but occurs throughout the water column with some contribution from interactions between the shelf and the adjacent Slope Sea reflected in cross-shelf motions of the shelfbreak front. The local warming on the shelf cannot explain the region's amplified rate of sea level rise relative to the global mean. Additionally, Ts exhibits significant interannual variability with the warmest anomalies increasing in intensity over the 37 year record even as the cold anomalies remain relatively uniform throughout the record. Ts anomalies are not correlated with annually averaged coastal sea level anomalies at zero lag. However, positive correlation is found between 2 year lagged Ts anomalies and coastal sea level anomalies, suggesting that the region's sea level anomalies may serve as a predictor of shelf temperature.
---------------------
Stronger warming amplification over drier ecoregions observed since 1979
Liming Zhou, Haishan Chen & Yongjiu Dai
Environmental Research Letters, June 2015
Abstract:
Observations show that the global mean surface temperature has increased steadily since the 1950s and this warming trend is particularly strong and linear over land after 1979. This paper analyzes the relationship between surface temperature trends observed over land for the period 1979–2012 and enhanced vegetation index (EVI), a satellite measured vegetation greenness index, by large-scale ecoregion. The land areas between 50°S and 50°N are classified into various large-scale ecoregions based on the climatological EVI values. The regional mean temperature trends exhibit significant spatial dependence on the regional mean EVI. In general, the warming rate increases dramatically with decreasing EVI, with the strongest warming rate seen over the driest ecoregions. When anthropogenic and natural forcings are included, climate models are generally able to reproduce observed major features of the spatial dependence. When only natural forcings are used, none of the observed features are simulated. Furthermore, the simulated temperature changes in the latter are mostly far outside the range of those in the former. These results suggest stronger warming amplification over drier ecoregions in the context of global warming, pointing mainly to human influence.
---------------------
Xiaochun Zhang & Ken Caldeira
Geophysical Research Letters, 16 June 2015, Pages 4548–4555
Abstract:
The Earth warms both when fossil fuel carbon is oxidized to carbon dioxide and when greenhouse effect of carbon dioxide inhibits longwave radiation from escaping to space. Various important time scales and ratios comparing these two climate forcings have not previously been quantified. For example, the global and time-integrated radiative forcing from burning a fossil fuel exceeds the heat released upon combustion within 2 months. Over the long lifetime of CO2 in the atmosphere, the cumulative CO2-radiative forcing exceeds the amount of energy released upon combustion by a factor >100,000. For a new power plant, the radiative forcing from the accumulation of released CO2 exceeds the direct thermal emissions in less than half a year. Furthermore, we show that the energy released from the combustion of fossil fuels is now about 1.71% of the radiative forcing from CO2 that has accumulated in the atmosphere as a consequence of historical fossil fuel combustion.
---------------------
Sea level rise projections for northern Europe under RCP8.5
Aslak Grinsted et al.
Climate Research, July 2015, Pages 15-23
Abstract:
Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the British Isles, the Baltic Sea, and the North Sea. The input to the regional sea level projection is a probabilistic projection of the major components of the global sea level budget. Local sea level rise is partly compensated by vertical land movement from glacial isostatic adjustment. We explore the uncertainties beyond the likely range provided by the IPCC, including the risk and potential rate of marine ice sheet collapse. Our median 21st century relative sea level rise projection is 0.8 m near London and Hamburg, with a relative sea level drop of 0.1 m in the Bay of Bothnia (near Oulu, Finland). Considerable uncertainties remain in both the sea level budget and in the regional expression of sea level rise. The greatest uncertainties are associated with Antarctic ice loss, and uncertainties are skewed towards higher values, with the 95th percentile being characterized by an additional 0.9 m sea level rise above median projections.
---------------------
Climate change tightens a metabolic constraint on marine habitats
Curtis Deutsch et al.
Science, 5 June 2015, Pages 1132-1135
Abstract:
Warming of the oceans and consequent loss of dissolved oxygen (O2) will alter marine ecosystems, but a mechanistic framework to predict the impact of multiple stressors on viable habitat is lacking. Here, we integrate physiological, climatic, and biogeographic data to calibrate and then map a key metabolic index — the ratio of O2 supply to resting metabolic O2 demand — across geographic ranges of several marine ectotherms. These species differ in thermal and hypoxic tolerances, but their contemporary distributions are all bounded at the equatorward edge by a minimum metabolic index of ~2 to 5, indicative of a critical energetic requirement for organismal activity. The combined effects of warming and O2 loss this century are projected to reduce the upper ocean’s metabolic index by ~20% globally and by ~50% in northern high-latitude regions, forcing poleward and vertical contraction of metabolically viable habitats and species ranges.
---------------------
Ocean acidification impairs crab foraging behavior
Luke Dodd et al.
Proceedings of the Royal Society: Biological Sciences, 7 July 2015
Abstract:
Anthropogenic elevation of atmospheric CO2 is driving global-scale ocean acidification, which consequently influences calcification rates of many marine invertebrates and potentially alters their susceptibility to predation. Ocean acidification may also impair an organism's ability to process environmental and biological cues. These counteracting impacts make it challenging to predict how acidification will alter species interactions and community structure. To examine effects of acidification on consumptive and behavioural interactions between mud crabs (Panopeus herbstii) and oysters (Crassostrea virginica), oysters were reared with and without caged crabs for 71 days at three pCO2 levels. During subsequent predation trials, acidification reduced prey consumption, handling time and duration of unsuccessful predation attempt. These negative effects of ocean acidification on crab foraging behaviour more than offset any benefit to crabs resulting from a reduction in the net rate of oyster calcification. These findings reveal that efforts to evaluate how acidification will alter marine food webs should include quantifying impacts on both calcification rates and animal behaviour.
---------------------
Diana Lane et al.
Climatic Change, July 2015, Pages 143-157
Abstract:
We analyzed the potential physical and economic impacts of climate change on freshwater fisheries and coral reefs in the United States, examining a reference case and two policy scenarios that limit global greenhouse gas (GHG) emissions. We modeled shifts in suitable habitat for three freshwater fish guilds and changes in coral reef cover for three regions. We estimated resulting economic impacts from projected changes in recreational fishing and changes in recreational use of coral reefs. In general, coldwater fisheries are projected to be replaced by less desirable fisheries over the 21st century, but these impacts are reduced under the GHG mitigation scenarios. Similarly, coral cover is projected to decline over the 21st century primarily due to multiple bleaching events, but the GHG mitigation scenarios delay these declines in Hawaii (but not in South Florida or Puerto Rico). Using a benefit-transfer approach, we estimated that global policies limiting GHG emissions would provide economic benefits in the range of $10–28 billion over the 21st century through maintaining higher values for recreational services for all freshwater fisheries and coral reefs, compared to the reference scenario. These economic values are a subset of the total economic and societal benefits associated with avoiding projected future declines in freshwater fisheries and coral reef cover due to unmitigated climate change.
---------------------
Ocean impact on decadal Atlantic climate variability revealed by sea-level observations
Gerard McCarthy et al.
Nature, 28 May 2015, Pages 508–510
Abstracts:
Decadal variability is a notable feature of the Atlantic Ocean and the climate of the regions it influences. Prominently, this is manifested in the Atlantic Multidecadal Oscillation (AMO) in sea surface temperatures. Positive (negative) phases of the AMO coincide with warmer (colder) North Atlantic sea surface temperatures. The AMO is linked with decadal climate fluctuations, such as Indian and Sahel rainfall, European summer precipitation, Atlantic hurricanes and variations in global temperatures. It is widely believed that ocean circulation drives the phase changes of the AMO by controlling ocean heat content. However, there are no direct observations of ocean circulation of sufficient length to support this, leading to questions about whether the AMO is controlled from another source. Here we provide observational evidence of the widely hypothesized link between ocean circulation and the AMO. We take a new approach, using sea level along the east coast of the United States to estimate ocean circulation on decadal timescales. We show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres — the intergyre region. These circulation changes affect the decadal evolution of North Atlantic heat content and, consequently, the phases of the AMO. The Atlantic overturning circulation is declining and the AMO is moving to a negative phase. This may offer a brief respite from the persistent rise of global temperatures, but in the coupled system we describe, there are compensating effects. In this case, the negative AMO is associated with a continued acceleration of sea-level rise along the northeast coast of the United States.
---------------------
David Mills et al.
Climatic Change, July 2015, Pages 163-178
Abstract:
This paper develops and applies methods to quantify and monetize projected impacts on terrestrial ecosystem carbon storage and areas burned by wildfires in the contiguous United States under scenarios with and without global greenhouse gas mitigation. The MC1 dynamic global vegetation model is used to develop physical impact projections using three climate models that project a range of future conditions. We also investigate the sensitivity of future climates to different initial conditions of the climate model. Our analysis reveals that mitigation, where global radiative forcing is stabilized at 3.7 W/m2 in 2100, would consistently reduce areas burned from 2001 to 2100 by tens of millions of hectares. Monetized, these impacts are equivalent to potentially avoiding billions of dollars (discounted) in wildfire response costs. Impacts to terrestrial ecosystem carbon storage are less uniform, but changes are on the order of billions of tons over this time period. The equivalent social value of these changes in carbon storage ranges from hundreds of billions to trillions of dollars (discounted). The magnitude of these results highlights their importance when evaluating climate policy options. However, our results also show national outcomes are driven by a few regions and results are not uniform across regions, time periods, or models. Differences in the results based on the modeling approach and across initializing conditions also raise important questions about how variability in projected climates is accounted for, especially when considering impacts where extreme or threshold conditions are important.
---------------------
Nicholas Fisichelli et al.
PLoS ONE, June 2015
Abstract:
Climate change will affect not only natural and cultural resources within protected areas but also tourism and visitation patterns. The U.S. National Park Service systematically collects data regarding its 270+ million annual recreation visits, and therefore provides an opportunity to examine how human visitation may respond to climate change from the tropics to the polar regions. To assess the relationship between climate and park visitation, we evaluated historical monthly mean air temperature and visitation data (1979–2013) at 340 parks and projected potential future visitation (2041–2060) based on two warming-climate scenarios and two visitation-growth scenarios. For the entire park system a third-order polynomial temperature model explained 69% of the variation in historical visitation trends. Visitation generally increased with increasing average monthly temperature, but decreased strongly with temperatures > 25°C. Linear to polynomial monthly temperature models also explained historical visitation at individual parks (R2 0.12-0.99, mean = 0.79, median = 0.87). Future visitation at almost all parks (95%) may change based on historical temperature, historical visitation, and future temperature projections. Warming-mediated increases in potential visitation are projected for most months in most parks (67–77% of months; range across future scenarios), resulting in future increases in total annual visits across the park system (8–23%) and expansion of the visitation season at individual parks (13–31 days). Although very warm months at some parks may see decreases in future visitation, this potential change represents a relatively small proportion of visitation across the national park system. A changing climate is likely to have cascading and complex effects on protected area visitation, management, and local economies. Results suggest that protected areas and neighboring communities that develop adaptation strategies for these changes may be able to both capitalize on opportunities and minimize detriment related to changing visitation.
---------------------
K. Strzepek et al.
Climatic Change, July 2015, Pages 127-141
Abstract:
Climate change impacts on water resources in the United States are likely to be far-reaching and substantial because the water is integral to climate, and the water sector spans many parts of the economy. This paper estimates impacts and damages from five water resource-related models addressing runoff, drought risk, economics of water supply/demand, water stress, and flooding damages. The models differ in the water system assessed, spatial scale, and unit of assessment, but together provide a quantitative and descriptive richness in characterizing water sector effects that no single model can capture. The results, driven by a consistent set of greenhouse gas (GHG) emission and climate scenarios, examine uncertainty from emissions, climate sensitivity, and climate model selection. While calculating the net impact of climate change on the water sector as a whole may be impractical, broad conclusions can be drawn regarding patterns of change and benefits of GHG mitigation. Four key findings emerge: 1) GHG mitigation substantially reduces hydro-climatic impacts on the water sector; 2) GHG mitigation provides substantial national economic benefits in water resources related sectors; 3) the models show a strong signal of wetting for the Eastern US and a strong signal of drying in the Southwest; and 4) unmanaged hydrologic systems impacts show strong correlation with the change in magnitude and direction of precipitation and temperature from climate models, but managed water resource systems and regional economic systems show lower correlation with changes in climate variables due to non-linearities created by water infrastructure and the socio-economic changes in non-climate driven water demand.
---------------------
Jeffrey Maynard et al.
Nature Climate Change, July 2015, Pages 688–694
Abstract:
Rising sea temperatures are likely to increase the frequency of disease outbreaks affecting reef-building corals through impacts on coral hosts and pathogens. We present and compare climate model projections of temperature conditions that will increase coral susceptibility to disease, pathogen abundance and pathogen virulence. Both moderate (RCP 4.5) and fossil fuel aggressive (RCP 8.5) emissions scenarios are examined. We also compare projections for the onset of disease-conducive conditions and severe annual coral bleaching, and produce a disease risk summary that combines climate stress with stress caused by local human activities. There is great spatial variation in the projections, both among and within the major ocean basins, in conditions favouring disease development. Our results indicate that disease is as likely to cause coral mortality as bleaching in the coming decades. These projections identify priority locations to reduce stress caused by local human activities and test management interventions to reduce disease impacts.
---------------------
James McFarland et al.
Climatic Change, July 2015, Pages 111-125
Abstract:
The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Yet fewer studies have explored the physical impacts of climate change on the power sector. The present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effects of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. The increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.