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Carbon dioxide is the most important greenhouse gas contributing to global warming. To help mitigate increasing CO2 concentrations, we investigate a method of carbon dioxide reduction using high-power electron beams, which can be used on an industrial scale. A series of experiments are conducted in which the reduction of CO2 is measured for different gas compositions and power deposition rates. An electron beam deposition model is applied to compute reduction rates of CO2 and energy cost for breaking a CO2 molecule in flue gas and pure carbon dioxide at atmospheric pressure. For flue gas consisting of 82% N2, 6% O2, and 12% CO2, the calculated energy cost is 85 eV per molecule. In order to dissociate 50% of the CO2 molecules, beam energy density deposition on the order of 20 J/cm³ is required. Electron beam irradiation of 12.6 liter gas volume containing 90% CO2 and 10% CH4 at beam energy density deposition of 4.2 J/cm³, accumulated over 43 shots in a 20 min interval, reduced the CO2 concentration to 78%. Analogous experiments with a gas mixture containing 11.5% CO2, 11.5% CH4, and balance of Ar, reduced the CO2 concentration to below 11% with energy deposition 0.71 J/cm³, accumulated over 10 shots in a 5 min interval. The experimental data and the theoretical predictions of CO2 reduction using pulsed electron beams are in agreement within the experimental error. Other techniques to enhance the removal of CO2 with pulsed electron beams are also explored, yielding new possible avenues of research. [ABSTRACT FROM AUTHOR]

Much scientific discussion has focused on rising greenhouse gas emissions and changing rainfall patterns in an increasingly warmer world. In fact, preventing the worst impacts of climate change on future human well-being will mean dealing with heightened flood and drought risks. The authors explain why the complex science of the shifting rainfall patterns and intensities caused by global warming is made even more complex by increasingly extreme air pollution. The article describes how scientists now think that the so-called “atmospheric brown cloud” over India affects the summer monsoon more than global warming does. In India, agriculture, industrial productivity, and life in general depend on monsoonal downpours that bring huge amounts of water to the subcontinent, feeding rivers and aquifers and cooling the land between June and September. As bad as it sounds, the scenario in which air pollution plays a major role in climate is actually good news for developing nations such as India. Pollution control is a regional and local problem that developing nations need to address in any case because of the huge human health costs related to it. The authors also warn that once pollution is brought under control, the full extent of global warming caused by developed nations’ greenhouse gas emissions from decades ago will become more prevalent and its impacts on the Indian monsoon will be unmasked. [ABSTRACT FROM AUTHOR]

This essay is part of a special issue entitled "Looking Backward, Looking Forward: HSNS at 50," edited by Erika Lorraine Milam. [ABSTRACT FROM AUTHOR]

This article discusses status of laws requiring the government to educate the public about indicators of global warming. The apparent marginalization of a U.S. government report, called "Climate Change Impacts on the United States: The Potential Causes of Climate Variability and Change," frequently called the National Assessment, by the administration of U.S. President George W. Bush is noted. Legal issues surrounding the National Assessment, including a lawsuit against its release filed by U.S. Representative James Inhofe and the Competitive Enterprise Institute (CEI), are discussed. Another lawsuit brought by environmentalist organizations including Greenpeace against the Bush Administration for their failure to continue the global warming assessment process is also noted.

Abstract: Likely climate change impacts include damages to agricultural production resulting from increased exposure to extreme heat. Considerable uncertainty remains regarding impacts on crop insurance programs. We utilize a panel of U.S. corn yield data to predict the effect of warming temperatures on the mean and variance of yields, as well as crop insurance premium rates and producer subsidies. While we focus on corn, we demonstrate that the subsidy impacts are likely to carry over to other major program crops. We find that warming decreases mean yields and increases yield risk on average, which results in higher premium rates. Under a 1°C warming scenario, we find that premium rates at the 90% coverage level will increase by 39% on average; however, there is considerable statistical uncertainty around this average as the 95% confidence interval spans from 22% to 61%. We also find evidence of extensive cross‐sectional differences as the county‐level rate impacts range from a 10% reduction to a 63% increase. Results indicate that exposure to extreme heat and changes in the coefficient of variation are large drivers of the impacts. Under the 1°C warming scenario, we find that annual subsidy payments for the crop insurance program could increase by as much as $1.5 billion, representing a 22% increase relative to current levels. This estimate increases to 3.7 billion (57%) under a 2°C warming scenario. Our results correspond to a very specific counterfactual: the marginal effect of warming temperatures under current technology, production, and crop insurance enrollments. These impacts are shown to be smaller than the forecasted impacts under a commonly used end‐of‐century general circulation model for even the most optimistic CO2 emissions projection. [ABSTRACT FROM AUTHOR]

Ecosystem-scale climate warming experiments have provided insight into the future dynamics of terrestrial ecosystems. In seasonally snow covered regions, changes in winter soil temperatures are largely mediated through shifts in depth and duration of snowpack that have implications for ecosystem processes. Despite known effects of changes in snowpack dynamics on ecosystem processes in seasonally snow covered environments, the extent to which warming experiments address winter climate change is unclear. Identifying how previous warming studies have addressed changes in winter climate is important for understanding what is known about interacting effects of climate change across seasons and to highlight gaps in our understanding of ecosystem responses to climate change throughout the year., We reviewed 64 published ecosystem-scale climate change manipulation experiments spanning three decades that were conducted in seasonally snow covered regions and simulated warmer growing season temperatures., We found that only 20% of experiments in snow covered ecosystems explicitly manipulated the winter climate to reflect projected changes in winter soil temperatures mediated through changes in snowpack over the next several decades. Experiments that manipulated both winter and the growing season climate employed a variety of passive and active warming methods. Above-ground active methods most realistically simulated projected changes in soil temperature that will be mediated through changes in snow cover. Experiments with distinct winter treatments were distributed among tundra, forest, grassland and wetland ecosystems and together show that shifts in winter climate have a strong influence on, and in some cases offset, observed responses to experimental warming in the growing season alone or across the year., By designing climate change experiments that examine the effects of winter and growing season climate change together, there is an opportunity to develop a better mechanistic understanding and more accurate projections of ecosystem responses to climate change that would not be evident from examining changes in either season alone. [ABSTRACT FROM AUTHOR]

This paper improves an extreme-value-theory-based detection and attribution method and then applies it to four types of extreme temperatures, annual minimum daily minimum (TNn) and maximum (TXn) and annual maximum daily minimum (TNx) and maximum (TXx), using the HadEX2 observation and the CMIP5 multimodel simulation datasets of the period 1951-2010 at 17 subcontinent regions. The methodology is an analog of the fingerprinting method adapted to extremes using the generalized extreme value (GEV) distribution. The signals are estimated as the time-dependent location parameters of GEV distributions fitted to extremes simulated by multimodel ensembles under anthropogenic (ANT), natural (NAT), or combined anthropogenic and natural (ALL) external forcings. The observed extremes are modeled by GEV distributions whose location parameters incorporate the signals as covariates. A coordinate descent algorithm improves both computational efficiency and accuracy in comparison to the existing method, facilitating detection of multiple signals simultaneously. An overall goodness-of-fit test was performed at the regional level. The ANT signal was separated from the NAT signal in four to six regions. In these analyses, the waiting times of the 1951-55 20-yr return level in the 2006-10 climate for the temperature of the coldest night and day were found to have increased to over 20 yr; the corresponding waiting times for the warmest night and day were found to have dropped below 20 yr in a majority of the regions. [ABSTRACT FROM AUTHOR]

The role of stationary planetary waves in the dynamical response of the Arctic winter stratosphere circulation to global warming is investigated here by analyzing simulations performed with atmosphere-only models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) driven by prescribed sea surface temperatures (SSTs). Climate models often simulate dynamical warming of the Arctic stratosphere as a response to global warming in association with a strengthening of the deep branch of the Brewer-Dobson circulation; however, until now, no satisfactory mechanism for such a response has been suggested. This study focuses on December-February (DJF) because this is the period when the troposphere and stratosphere are strongly coupled. When forced by increased SSTs, all the models analyzed here simulate Arctic stratosphere dynamical warming, mostly due to increased upward propagation of quasi-stationary wavenumber 1, as diagnosed by the meridional eddy heat flux. Further, it is shown that the stratospheric warming and increased wave flux to the stratosphere are related to the strengthening of the zonal winds in subtropics and midlatitudes near the tropopause. Evidence presented in this paper corroborate climate model simulations of future stratospheric changes and suggest a dynamical warming of the Arctic polar vortex as the most likely response to global warming. [ABSTRACT FROM AUTHOR]

Accelerated loss of ice from Greenland and Antarctica has been observed in recent decades. The melting of polar ice sheets and mountain glaciers has considerable influence on sea level rise in a changing climate. Ice thickness is a key factor in making predictions about the future of massive ice reservoirs. The ice thickness can be estimated by calculating the exact location of the ice surface and subglacial topography beneath the ice in radar imagery. Identifying the locations of ice surface and bottom is typically performed manually, which is a very time-consuming procedure. Here, we propose an approach, which automatically detects ice surface and bottom boundaries using distance-regularized level-set evolution. In this approach, the complex topology of ice surface and bottom boundary layers can be detected simultaneously by evolving an initial curve in the radar imagery. Using a distance-regularized term, the regularity of the level-set function is intrinsically maintained, which solves the reinitialization issues arising from conventional level-set approaches. The results are evaluated on a large data set of airborne radar imagery collected during a NASA IceBridge mission over Antarctica and show promising results with respect to manually picked data. [ABSTRACT FROM PUBLISHER]

Objective To explore the effects of long-term climate trends and short-term weather fluctuations, evaluations of scientists and science, political predispositions, religious affiliation, the information environment, and demographic attributes on individuals' views about whether global warming exists and, if so, whether it is a result of natural cycles or human activity. Methods We use data from the 2009 Pew General Public Science Survey, along with data on long- and short-term patterns of temperature and precipitation in individuals' home communities. Results We find that long-term trends in summer temperatures influence perceptions of global warming. Individuals who reside in communities with long-term warming of summer temperatures that are coupled with long-term cooling of spring temperatures are significantly more likely to perceive that global warming exists and is due to human activity. We also find that Americans' attitudes toward scientists and science, political dispositions, evangelical religious affiliation, education, and some demographic attributes all have discernible effects on their perceptions of anthropogenic (man-made) global warming. Conclusion Individuals' attitudes toward global warming are influenced by long-term temperature trends in their home communities, as well as a variety of attitudinal and demographic attributes. [ABSTRACT FROM AUTHOR]

Detection of small decadal-scale variation amidst larger variations on smaller timescales is carried out here by geometrical segregation rather than filtering. Sea surface temperature (SST) annual cycle is represented as a point in a 12-dimensional space and thermal history as a path connecting successive points. Drift of the domain of decadal variations in the state space is taken as a measure of change from one decade to another. Visualization of the path in the 12-dimensional space is achieved by projecting it on planes. A matrix transformation gives an orthogonal decomposition of the annual cycle resembling Fourier series. The specific problem investigated here is the response of the Northern, the Tropical and the Southern Oceanic Regions (NOR, 30°-90°N; TOR, 30°S-30°N; SOR, 90°-30°S) to global warming during 1951-2010. The results are based on the Extended Reconstructed Sea Surface Temperature version 4 (ERSSTv4) database. Several interesting findings are obtained. The decadal scale warming has a seasonal variation, the largest being in the NOR (~0.26°C to ~0.57°C), in 2001-10. The consequential change in the annual cycle is increase in the amplitude of the annual mode in addition to increase in the annual mean. Decade-on-decade SST increase has peaked first in the SOR in 1971-80, and last in the NOR in 2001-10. [ABSTRACT FROM AUTHOR]

Purpose: Our aim is to assess the comparability and generic applicability of harmonized published lifecycle assessment (LCA) studies on water supply systems. In the absence of localized life cycle inventories for water systems, generic or country specific databases may be inadequate if applied elsewhere. The objectives of this paper are to calculate the potential magnitude of errors introduced by this practice and recommend ways to better account for sources of impact variability. Methods: In this study, harmonization has been carried out rigorously, utilizing a systematic differentiation of the subsystems, functional units, and system boundaries referenced in over 100 candidate studies, resulting in a comparable subset of 34 LCA studies. Statistical techniques (cluster analysis and Welch's analysis of variance) were used to isolate and validate the main sources of variation in impact scores and identify the sub-systems in which these are most pronounced. The significance of technology-specific contribution to the impacts was compared to the significance of electricity as a contributing factor to the global warming potential (GWP) by applying statistical correlation analysis. Results and discussion: Our review revealed that most of the published LCAs analyzed water systems in well-developed countries. Large variation was found in the impacts of water supply systems (e.g., GWP between 0.16 and 3.4 kg CO2-eq/m of supplied water), with mean value of 0.84 kg CO2-eq/m3 and median of 0.57 kg CO2-eq/m3. The main contributor to GWP is water production and desalination in particular, making water production the most important differentiating factor. Cluster analysis also showed that production technology is the most important differentiating factor with respect to terrestrial acidification, ozone depletion, eutrophication, and abiotic depletion impacts of water production systems. There is a weak correlation between impact scores of electricity mixes and entire water supply systems. Conclusions: An LCA of water-intensive products drawing from a standard life cycle inventory databases could be substantially inaccurate, especially in a region with desalination. More accurate results can be achieved by taking local water production technology into account. Meta-analysis is a useful tool to explore the sources of variance in the impacts of water systems. Applying harmonized results is a cost-effective way for obtaining more accurate LCA results as compared to applying generic databases only. [ABSTRACT FROM AUTHOR]

Purpose: The fifth assessment report by the IPCC includes methane oxidation as an additional indirect effect in the global warming potential (GWP) and global temperature potential (GTP) values for methane. An analysis of the figures provided by the IPCC reveals they lead to different outcomes measured in CO-eq., depending on whether or not biogenic CO emissions are considered neutral. In this article, we discuss this inconsistency and propose a correction. Methods: We propose a simple framework to account for methane oxidation in GWP and GTP in a way that is independent on the accounting rules for biogenic carbon. An equation with three components is provided to calculate metric values, and its application is tested, together with the original IPCC figures, in a hypothetical example focusing on GWP100. Results and discussion: The hypothetical example shows that the only set of GWP100 values consistently leading to the same outcome, regardless of how we account for biogenic carbon, is the one proposed in this article. Using the methane GWP100 values from the IPCC report results in conflicting net GHG emissions, thus pointing to an inconsistency. Conclusions: In order to consistently discriminate between biogenic and fossil methane sources, a difference of 2.75 kg CO-eq. is needed, which corresponds to the ratio of the molecular weights of CO and methane (44/16). We propose to correct the GWP and GTP values for methane accordingly. [ABSTRACT FROM AUTHOR]

1. In order to assess the impact of global warming on the biodiversity of the tropical high Andean páramo ecosystem, we compared historical and recent surveys of ground beetle communities along elevational gradients of the Pichincha volcano (Northern Ecuador). The studied datasets date to 1880, 1985/86 and 2013/15. 2. From 1880 to 1985, the bottom range of at least one stenotopic and wingless high-altitude species, Dyscolus diopsis, has shifted approximately 300 m upward, with the resulting area reduction of more than 90% from >12 km² to <1 km², which highlights the probability of future local extinctions on the Pichincha as well as on other mountains of Ecuador. 3. Over a shorter period of time, the comparison of the 1985/86 and 2013/14 datasets indicates that the lower limit of the superpáramo ground beetle community has shifted upwards from circa 4300 m to circa 4400 m. Different individual responses are recorded among the species. Some of them did not experience any significant change, whereas the upper limit of one of the grassland generalists has shifted upwards at least 400 m in 28 years. 4. These results suggest that the response to global warming varies from one species to the other, depending on their degree of specialisation and tolerance. They call for the implementation of a monitoring programme that would use carabid assemblages as an indicator of the impact of climate change on the páramo ecosystem, in combination with other proxies. [ABSTRACT FROM AUTHOR]

Robust appraisals of climate impacts at different levels of global-mean temperature increase are vital to guide assessments of dangerous anthropogenic interference with the climate system. The 2015 Paris Agreement includes a two-headed temperature goal: "holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 °C". Despite the prominence of these two temperature limits, a comprehensive overview of the differences in climate impacts at these levels is still missing. Here we provide an assessment of key impacts of climate change at warming levels of 1.5 °C and 2 °C, including extreme weather events, water availability, agricultural yields, sea-level rise and risk of coral reef loss. Our results reveal substantial differences in impacts between a 1.5 °C and 2 °C warming that are highly relevant for the assessment of dangerous anthropogenic interference with the climate system. For heat-related extremes, the additional 0.5 °C increase in global-mean temperature marks the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions. Similarly, this warming difference is likely to be decisive for the future of tropical coral reefs. In a scenario with an end-of-century warming of 2 °C, virtually all tropical coral reefs are projected to be at risk of severe degradation due to temperature-induced bleaching from 2050 onwards. This fraction is reduced to about 90 % in 2050 and projected to decline to 70 % by 2100 for a 1.5 °C scenario. Analyses of precipitation-related impacts reveal distinct regional differences and hot-spots of change emerge. Regional reduction in median water availability for the Mediterranean is found to nearly double from 9 % to 17 % between 1.5 °C and 2 °C, and the projected lengthening of regional dry spells increases from 7 to 11 %. Projections for agricultural yields differ between crop types as well as world regions. While some (in particular high-latitude) regions may benefit, tropical regions like West Africa, South-East Asia, as well as Central and northern South America are projected to face substantial local yield reductions, particularly for wheat and maize. Best estimate sea-level rise projections based on two illustrative scenarios indicate a 50 cm rise by 2100 relative to year 2000-levels for a 2°C scenario, and about 10 cm lower levels for a 1.5 °C scenario. In a 1.5 °C scenario, the rate of sea-level rise in 2100 would be reduced by about 30 % compared to a 2 °C scenario. Our findings highlight the importance of regional differentiation to assess both future climate risks and different vulnerabilities to incremental increases in global-mean temperature. The article provides a consistent and comprehensive assessment of existing projections and a good basis for future work on refining our understanding of the difference between impacts at 1.5 °C and 2 °C warming. [ABSTRACT FROM AUTHOR]

Drought is a serious ecological problem around the world, and its impact on crops and water availability for humans can jeopardize human life. Although drought has always been common, the drought risk has become increasingly prominent because of the climatic warming that has occurred during the past century. However, it still does not comprehensively understand the mechanisms that determine the occurrence of the drought risk it poses to humans, particularly in the context of global climate change. In this paper, we summarize the progress of research on drought and the associated risk, introduce the principle of a drought 'transition' from one stage to another, synthesize the characteristics of key factors and their interactions, discuss the potential effect of climatic warming on drought risk, and use this discussion to define the basic requirements for a drought risk management system. We also discuss the main measures that can be used to prevent or mitigate droughts in the context of a risk management strategy. [ABSTRACT FROM AUTHOR]

Purpose: This study examines the utility of descriptive statistics and factor analysis in the interpretation of an LCA data set. It is believed that the use of descriptive statistics and factor analysis provides a comprehensive summary of the data, and insight on internal validity, which improves interpretation of results. The current study also provides a pretext for subsequent analyses with inferential statistics. Methods: Nine building envelope combinations were analyzed according to five service life models ( N = 45, 45 data points). Three environmental indicators were used to characterize the data: global warming potential (GWP), atmospheric eco-toxicity (ECO), and atmospheric acidification (ACID) from the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) assessment method. Descriptive statistics measured minimum, maximum, mean, standard deviation, skewness, and kurtosis. For the factor analysis, data were disaggregated according to nine variables, including cumulative life cycle impact, major replacement, major replacement (frequency), minor replacement, major repairs, minor repairs, inspections 1 and 2, and total transportation ( N = 45, 405 data points). All statistical operations were performed using SPSS software. Results and discussion: Descriptive statistics show a relatively normal data distribution for GWP. Data distributions for ECO and ACID deviated slightly from normal, which was confirmed through Shapiro-Wilk and Kolmogorov-Smirnov tests. Factor analysis resulted in three factors for GWP and ECO, and two factors for ACID. In each analysis, cumulative life cycle impact, major replacement, and major replacement (frequency) aligned as variables in a common factor. This alignment corroborates previous findings. Other variables in the factor analysis were less clearly or inconsistently aligned. Conclusions: The descriptive statistics provide important information about the distribution of data in the study. The data are determined to be suitable for further analysis using inferential univariate and multivariate statistical tests, a topic that is examined in part 2 of this study as reported by Grant et al. (Int J Life Cycle Assess, 2015). The factor analysis used in the study corroborates the conclusions of previous studies and provides a basis for future statistical analyses. [ABSTRACT FROM AUTHOR]

Purpose: This study examines the use of inferential statistics, specifically multivariate correlation and regression, as a means of interpreting LCA data. It is believed that these methods provide additional context in understanding data and results, and may serve as a way to present the uncertain results that are inherent to LCA. Methods: Nine building envelope combinations were analyzed according to five service life models ( N = 45). Three environmental indicators were used: global warming potential, atmospheric ecotoxicity, and atmospheric acidification from the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts assessment method. Multivariate correlation was performed using nine variables, including cumulative life cycle impact, major replacement, major replacement (frequency), minor replacement, major repairs, minor repairs, inspections 1 and 2, and total transportation ( N = 45, 405 data points). The same data set was used for the regression analysis, although the variables were limited to major replacement, minor replacement, major repair, and minor repair ( N = 45, 225 data points). SPSS software was used for all statistical calculations. Results and discussion: Multivariate correlation analysis showed strong, statistically significant correlations between cumulative life cycle impact and major replacement across all environmental indicators. Similarly, the regression analysis showed strong R values between cumulative life cycle impact and major replacement, such that the influence of all other variables was considerably diminished. Conclusions: The use of inferential statistics provides useful information with respect to the strength and statistical significance of correlations between variables as in multivariate correlation, and allows for predictive capacity of impact, as demonstrated through regression analysis. Further studies should be conducted to confirm the added value of these analytical tools. [ABSTRACT FROM AUTHOR]

Climate change is expected to profoundly alter the growing conditions of agricultural crops, potentially causing decline in food production in several parts of the world. A switch from crops and crop varieties currently grown to others that are better adapted to new environmental conditions has been suggested as one possible adaptation strategy. While research has documented the upward migration of wild species linked to recent warming in mountain environments, there has been little empirical research on corresponding shifts in the ranges of cultivated species. This study examines changes in the elevation of maize cultivation on the slopes of Mt. Cotacachi, a volcano located in the Northern Ecuadorian highlands. The results show that during the past two decades, farmers in four communities have expanded maize cultivation an estimated 200–300 m in elevation, linked to their observations of climatic and environmental change. This suggests that in tropical mountain regions like the Andes that exhibit closely stacked agroecological zones, the upward movement of local crops and crop varieties constitutes one feasible locally based adaptive response to changes in growing conditions induced by global warming. [ABSTRACT FROM PUBLISHER]

The ecology of scleractinian corals may be understood through comparisons between population demographic data and environmental parameters. Growth (growth constant and maximum size) and demographic parameters (population structure stability, instantaneous mortality rate, average age of individuals, percentage of immature individuals, age at maximum biomass, and average age of biomass) of the solitary, non-zooxanthellate, and temperate coral Caryophyllia inornata were investigated at six sites along an 8° latitudinal gradient of temperature and solar radiation (SR) on the western Italian coasts. Growth parameters were homogeneous among populations across the investigated latitudinal range. While demographic parameters were not correlated with depth temperature, populations were progressively less stable and showed a deficiency of young individuals with increasing SR, likely as a result of the lowered energetic resources due to reduced zooplankton availability. These results contrast with data from another Mediterranean non-zooxanthellate solitary coral, Leptopsammia pruvoti, investigated along the same gradient, which shows no correlation between population demography and temperature or SR. [ABSTRACT FROM AUTHOR]

Epilithic algal communities play critical ecological roles on coral reefs, but their response to individual and interactive effects of ocean warming (OW) and ocean acidification (OA) is still largely unknown. We investigated growth, photosynthesis and calcification of early epilithic algal community assemblages exposed for 6 months to four temperature profiles (−1.1, ±0.0, +0.9, +1.6 °C) that were crossed with four carbon dioxide partial pressure (pCO) levels (360, 440, 650, 940 µatm), under flow-through conditions and natural light regimes. Additionally, we compared the cover of heavily calcified crustose coralline algae (CCA) and lightly calcified red algae of the genus Peyssonnelia among treatments. Increase in cover of epilithic communities showed optima under moderately elevated temperatures and present pCO, while cover strongly decreased under high temperatures and high-pCO conditions, particularly due to decreasing cover of CCA. Similarly, community calcification rates were strongly decreased at high pCO under both measured temperatures. While final cover of CCA decreased under high temperature and pCO (additive negative effects), cover of Peyssonnelia spp. increased at high compared to annual average and moderately elevated temperatures. Thus, cover of Peyssonnelia spp. increased in treatment combinations with less CCA, which was supported by a significant negative correlation between organism groups. The different susceptibility to stressors most likely derived from a different calcification intensity and/or mineral. Notably, growth of the epilithic communities and final cover of CCA were strongly decreased under reduced-pCO conditions compared to the present. Thus, CCA may have acclimatized from past to present-day pCO conditions, and changes in carbonate chemistry, regardless in which direction, negatively affect them. However, if epilithic organisms cannot further acclimatize to OW and OA, the interacting effects of both factors may change epilithic communities in the future, thereby likely leading to reduced reef stability and recovery. [ABSTRACT FROM AUTHOR]

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

Extreme weather events have become more frequent and intense under global warming in recent years, which has attracted much attention of scholars at home and abroad. In this paper, we used data sets of daily precipitation recorded at 499 meteorological stations to analyze the temporal and spatial variations of precipitation extremes in China over the past 50 years (1960-2009). Through the comparison of detrended fluctuation analysis (DFA) and the percentile method, DFA was selected to define the thresholds of precipitation extremes in China. Temporal variations of extreme precipitation amount, frequency, and intensity were analyzed in four major regions: Northwest China, the Qinghai-Tibet region, North China, and South China. Spatial distributions were obtained by the Kriging interpolation method, and then, we examined the varying tendencies of extreme precipitation amount, frequency, and intensity by the Mann-Kendall test. The results show that increasing trends are dominant for all indices over China; extreme precipitation amount and frequency appear to have risen since 1970-1979, but there are some regional differences. The Qinghai-Tibet region and South China have an ascending trend, and Northwest China maintains balance while North China has a descending trend. The amount and intensity of precipitation extremes are decreasing from southeastern coastal areas to northwestern inlands, and the frequency of precipitation extremes is randomly distributed. However, they are all high in the Sichuan Basin, the middle and lower Yangtze River, and the southern part of South China. Trends of most stations are statistically insignificant, but the percentage of stations with a significant increased trend in the Qinghai-Tibet region is larger than that of other regions. [ABSTRACT FROM AUTHOR]

Heat waves are one of the main concerns related to the impacts of climate change, because their frequency and severity are projected to increase in a future climate. The objectives of this work are to study the long-term variability of heat waves over Argentina and to estimate recurrence probability of the most severe 2008 heat wave in Buenos Aires. We used three definitions of heat waves that were based on (1) daily maximum temperature above the 90th percentile (MaxTHW), (2) daily minimum temperature above the 90th percentile (MinTHW) and (3) both maximum and minimum temperatures above the corresponding 90th percentiles (EHW). The minimum length of a heat wave was 3 days, and the analysis was performed over the October-March period. Decadal values in Buenos Aires experienced clear increases in heat waves according to MinTHW and EHW, with the highest frequency for both in the 2001-2010 decade, but at other stations, combinations of different trends and decadal variability resulted in some cases in a decrease of extreme heat waves. In the north-western part of the country, a strong positive change in the last decade was found, mainly due to the increment in the persistence of MinTHW but also accompanied by increases in MaxTHW. In general, other stations show a clear positive trend in MinTHW and decadal variability in MaxTHW, with the largest EHW cases in the last decade. We also estimated recurrence probability of the longest and most severe heat wave in Buenos Aires (over 1909-2010, according to intensity measured by the cumulative excess of maximum daily temperature above the 90th percentile) that occurred from 3 to 14 November 2008, by means of simulations with a stochastic first-order autoregressive model. The recurrence probability of such long and severe heat wave is small in the present climate but it is likely to increase substantially in the near future even under a moderate warming trend. [ABSTRACT FROM AUTHOR]

As climate change could significantly influence crop phenology and subsequent crop yield, adaptation is a critical mitigation process of the vulnerability of crop growth and production to climate change. Thus, to ensure crop production and food security, there is the need for research on the natural (shifts in crop growth periods) and artificial (shifts in crop cultivars) modes of crop adaptation to climate change. In this study, field observations in 18 stations in North China Plain (NCP) are used in combination with Agricultural Production Systems Simulator (APSIM)-Maize model to analyze the trends in summer maize phenology in relation to climate change and cultivar shift in 1981-2008. Apparent warming in most of the investigated stations causes early flowering and maturity and consequently shortens reproductive growth stage. However, APSIM-Maize model run for four representative stations suggests that cultivar shift delays maturity and thereby prolongs reproductive growth (flowering to maturity) stage by 2.4−3.7 day per decade (d 10a). The study suggests a gradual adaptation of maize production process to ongoing climate change in NCP via shifts in high thermal cultivars and phenological processes. It is concluded that cultivation of maize cultivars with longer growth periods and higher thermal requirements could mitigate the negative effects of warming climate on crop production and food security in the NCP study area and beyond. [ABSTRACT FROM AUTHOR]

Intraseasonal variability (ISV) is a primary source for the sub-seasonal prediction that affects the livelihood of billions of people. Interannual variation of ISV intensity is important for seasonal prediction of ISV impacts on severe weathers. Existing measures of overall tropical ISV intensity, however, do not show any significant simultaneous relationship with external sea surface temperature anomalies (SSTAs). In this study, it is proposed that the ISV intensity, represented by the seasonal standard deviation of the 30-90-day filtered outgoing longwave radiation (OLR), has a good relation with the external SSTAs. With this measure, two major components of the interannual variability of global ISV intensity are detected for both boreal summer and winter: EOF1 calls its variability over the central Pacific and EOF2 is associated with the variability over the Indo-Pacific Warm Pool region. More importantly, each of these two components is significantly related to SSTAs over a specific tropical region. The central Pacific ISV intensity is strong during central Pacific warming, while the ISV intensity is strong over the Indo-Pacific Warm Pool region during eastern Pacific cooling. The eastern and central Pacific warming has very different impacts on the ISV intensity: The eastern Pacific warming largely reduces the winter ISV intensity over the Indian Ocean, while the central Pacific warming only induces neutral winter ISV intensity anomalies over the Indian Ocean. In the summer, the ISV intensity variability is confined near the equator associated with the central Pacific warming; the eastern Pacific warming, however, induces large ISV intensity variability over the western North pacific because of strong northeastward propagation of the boreal summer ISV under the easterly vertical shear. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to provide a summary of Morocco's climate extreme trends during the last four decades. Indices were computed based on a daily temperature and precipitation using a consistent approach recommended by the ETCCDI. Trends in these indices were calculated at 20 stations from 1970 to 2012. Twelve indices were considered to detect trends in temperature. A large number of stations have significant trends and confirm an increase in temperature, showing increased warming during spring and summer seasons. The results also show a decrease in the number of cold days and nights and an increase in the number of warm days and nights. Increasing trends have also been found in the absolute warmest and coldest temperatures of the year. A clear increase is detected for warm nights and diurnal temperature range. Eight indices for precipitation were also analyzed, but the trends for these precipitation indices are much less significant than for temperature indices and show more mixed spatial patterns of change. Heavy precipitation events do not exhibit significant trends except at a few locations, in the north and central parts of Morocco, with a general tendency towards drier conditions. The correlation between these climate indices and the large-scale atmospheric circulations indices such as the NAO, MO, and WEMO were also analyzed. Results show a stronger relationship with these climatic indices for the precipitation indices compared to the temperature indices. The correlations are more significant in the Atlantic regions, but they remain moderate at the whole country scale. [ABSTRACT FROM AUTHOR]

Daily temperature and precipitation data from 15 rain gauges covering a period of 1957-2011 were analyzed using the Mann-Kendall trend test with the aim to investigate changing characteristics of weather extremes in the Poyang Lake basin, the largest freshwater lake in China. Also, the connection between El Niño Southern Oscillation (ENSO) and precipitation extremes is analyzed and possible causes for the connection are briefly discussed. Results indicate that (1) warming, characterized by a decreasing trend in frost days and a significant decrease of temperature extremes defined by lower temperature, in the Poyang Lake basin is observed. Temperature extremes, defined by higher temperature indices such as hot days, exhibit moderate changes with no significant trends. Moreover, warming occurs mainly in the northern part of the Poyang Lake basin; (2) precipitation changes are intensifying as reflected by increasing precipitation extremes. However, these changes are different from 1 month to another and the intensification is found mainly in winter and/or summer months; (3) the influence of ENSO on precipitation changes in the Poyang Lake basin is evident with a time lag of longer than 3 months. This should be due to the fact that higher sea surface temperature tends to trigger the occurrence of convective precipitation regimes. Results of this study are important for modeling the occurrence of precipitation extremes in a changing climate and regional climatic responses to global climate changes. [ABSTRACT FROM AUTHOR]

Alpine ecosystems occur under extreme climatic conditions and, as a result, house a unique and vulnerable biota. They are very scarce at tropical latitudes; in Mexico occur mainly along the Trans-Mexican Volcanic Belt, where species richness is not high but narrow endemics stand out. We investigate the effects of climate change under hypothesized contrasting climate warming scenarios using ecological niche modeling of five microendemic alpine species. Occurrence data was obtained mainly from field trips, but herbaria were also examined. A total of 21 climatic and topographic variables, as well as individual selections of 12-16 variables were employed to construct models with Maxent and GARP. Depending on the number of occurrences, current models were validated with Partial-ROC or Jackknife procedures; and projections to 2050 and 2070 were made using two Representative Concentration Pathways and two Global Circulation Models. All species' models showed a clear pattern of contraction under the explored scenarios; over 58 % of contemporary climatic distribution disappeared, suggesting that analyzed species face imminent extinction due to climatic habitat loss. The models are useful in representing the endemic component of Mexican alpine grassland by reciprocal correspondence in geographic distribution, and we consider it as a highly endangered ecosystem due to climate change, which is probably applicable to other tropical alpine ecosystems. The Pico de Orizaba volcano seems the best option to preserve due to its extension and elevation. However, further studies at finer scales are needed to improve in situ preservation and conservation strategies that include translocation, assisted migration and seed banking. [ABSTRACT FROM AUTHOR]

Global warming has the potential to affect many animal species, in particular temperature-dependent insects with their short generation times and high reproductive rates which facilitate adaptations to long-term climatic fluctuations. Aphids are the model species in studying the association of insect biology with large-scale climate fluctuations because they multiply only within a certain range of temperatures and their rate of development directly depends on temperature. Here, we investigate the effect of climate warming on phenology and voltinism of the juniper aphid (Cinara juniperiDe Geer 1773), a native species of a temperate climate zone in Poland. We also experimentally test for the temperature optimum of the study species. Our study demonstrated that environmental conditions significantly affected phenology of juniper aphid. The timing of larval emergence depended on mean temperatures in March, and in warmer years larvae appeared earlier. The emergence of the sexual generation was related to mean temperatures in August, and higher temperatures resulted in later sexual reproduction. Despite the elongation of the entire life cycle, by almost 3 months, we observed only one additional generation in warmer years. A possible explanation for this pattern may be that the increase in temperature recorded in recent years went beyond the temperature optimum of the study species. Our chamber experiment supports this assumption – juniper aphids developed faster and reproduced more effectively at 20 °C than at 25 °C. [ABSTRACT FROM PUBLISHER]

Among the possible options for the transformation of plant oils and animal fats to biodiesel, the alcoholysis process has been frequently selected. The rate of alcoholysis reaction is accelerated using a catalytic material. This article reviews different nature of catalysts utilized to assist the process of biodiesel production. The chemical properties of both homogeneous and heterogeneous catalysts enable their sub-division into acidic and basic materials. The proficiency of several heterogeneous catalytic systems and the possible route of alcoholysis reaction using different materials is systematically discussed. Furthermore, the factors influencing the performance of catalysts are also considered. [ABSTRACT FROM PUBLISHER]

The author argues that originally concern about the destruction of the ecosphere rested on an awareness of the damaging technologies which sustained the lifestyle of the rich world. There was an emphasis on the unsustainability of development based on a permanently expanding economy and the need to address the abuse of resources and extravagance of the North at the expense of the South. Now, and particularly after the disintegration of the Soviet Union, the rich world has successfully exported its development paradigm and managed to attribute climate change to ‘anthropogenic activity’ thereby making everyone appear equally culpable for degrading the planet. In the process, discussion has moved from the need to curb consumption to the necessity of changing energy sources. [ABSTRACT FROM AUTHOR]

Researchers have been focused on refrigerant R744 because it is a natural refrigerant and its Global Warming Potential value is 1. However, coefficient of performance (COP) of refrigeration systems that use R744 as refrigerant has lower values than refrigeration systems that use CFC and HCFC refrigerants as refrigerant. Previous studies showed that COP of the refrigeration system with R744 can be increased by using two-phase ejector. In this study, additional evaporators are used instead of the separator. Thus, the refrigeration system can be constructed more accurately. Theoretical analysis of the bi-evaporator refrigeration system with two-phase ejector is carried out by using energy and momentum equations. COP and entrainment ratio are obtained for various operating conditions. Results show that COP improvement can be achieved about 21% for proper design in Mediterranean climate zone. [ABSTRACT FROM AUTHOR]

Sociologists have done important research documenting the key role that think tanks play in the climate change denialism movement in the United States, which has sought to mislead the American public about the realities of global warming. Sociologists have not, however, assessed the full range of ways that think tanks are responding to - or planning for - global environmental change. This article proposes a typology of elite responses to global warming, which goes beyond denialism to include (i) limited climate mitigation, (ii) climate adaptation/privileged accommodation, and (iii) climate opportunism. Ultimately, this article provides insights on ways to build upon previous research in both environmental and political sociology to study the interface between elite-driven policy, climate change, and capitalism. [ABSTRACT FROM AUTHOR]

Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability and sensitivity were evaluated, the carbon intensity of the local electricity grid and the efficiency of electricity production by the co-digestion with the energy recovery process were the most important for determining the relative global warming potential results. [ABSTRACT FROM AUTHOR]

Many ectothermic species are currently expanding their distributions polewards due to anthropogenic global warming. Molecular genetic mechanisms facilitating range expansion under these conditions are largely unknown, but understanding these could help mitigate expanding pests and disease vectors, or help explain why some species fail to track changing climates. Here, using RNA-seq data, we examine genomewide changes in gene expression under heat and cold stress in the range-expanding damselfly Ischnura elegans in northern Europe. We find that both the number of genes involved and levels of gene expression under heat stress have become attenuated during the expansion, consistent with a previously reported release from selection on heat tolerances as species move polewards. Genes upregulated under cold stress differed between core and edge populations, corroborating previously reported rapid adaptation to cooler climates at the expansion front. Expression of sixty-nine genes exhibited a region x treatment effect; these were primarily upregulated in response to heat stress in core populations but in response to cold stress at the range edge, suggesting that some cellular responses originally adapted to heat stress may switch to cold-stress functionality upon encountering novel thermal selection regimes during range expansion. Transcriptional responses to thermal stress involving heat-shock and neural function genes were largely geographically conserved, while retrotransposon, regulatory, muscle function and defence gene expression patterns were more variable. Flexible mechanisms of cold-stress response and the ability of some genes to shift their function between heat and cold stress might be key mechanisms facilitating rapid poleward expansion in insects. [ABSTRACT FROM AUTHOR]

Crop wild relatives, the progenitors and kin of domesticated crop species, promise breeders a potent weapon against climate change. Having evolved outside the pampered environs of farms, wild relatives tend to be more rugged to survive temperature, salt, floods, and drought--all the extremes characteristic of a warming planet. But who will benefit from re-wilded crops? What kinds of agricultural systems will they tend to support? And can wild relatives be protected before they are lost under pavement, desertification, and expanding industrial farms? In this essay, I explore different visions of conservation and use for crop wild relatives. With CWR valued at an estimated $115-120 billion to the global economy annually, many researchers suggest ancient germplasm can be harnessed to feed billions in a warming world. Others look more closely at ancient customs and farmer knowledge that have long promoted conservation of wild species within and around cultivated landscapes. By intentionally planting crops at field borders, farmers also perform "in vivo" breeding. I conclude that wild relatives hold much potential to reinfuse diversity into eroded crop gene pools, providing greater systemic resilience. But unless we consider who controls seeds, intellectual property, and wild and agricultural lands, CWR innovations will only prop up an agriculture that ultimately undercuts crop and wild relative renewal. [ABSTRACT FROM AUTHOR]

Major green house gases are carbon dioxide, methane, and nitrous oxide which are emitted directly and indirectly by ruminants. More than 80 per cent methane is normally produced during enteric fermentation. Methane has the second largest contributor to the green house effect and has 23 times more global warming potential than carbon dioxide. The Indian contribution of methane from all sources is around 12 per cent of total world production, in which mostly by emission by ruminants. India possesses largest ruminant population. An effort is made to mitigate the methane production in the ruminants. Nutritional management like good quality feed, use of higher concentrates, supplementing cattle diets with urea molasses block licks, fiber palletisation, breeding management like AI., ETT, In vitro fertilization which improves genetics and reproductive efficiency can also improve production efficiency which reduces green house gas emission. [ABSTRACT FROM AUTHOR]

Global warming is a great concern throughout the world. Being poikilothermic in nature insects are greatly affected by changing temperature. Insect will experience additional life cycles with rapid growth rate. As a result of changes in the population dynamics including distribution and migration the reliability on current insect pest ETL will be reduced. Increased insect pests outbreak will affect agricultural production. Research on basic biology of insect, population dynamics and behavior patterns should be focused to ascertain the effect of global warming on insect behavior. [ABSTRACT FROM AUTHOR]

Biocovers are a promising technology for mitigating methane (CH4) emission from landfills. The geotechnical performance of the biocover material is one of the design criteria of biocovers. However, current understanding of the geotechnical behavior of biocovers under freeze-thaw conditions is limited. In the present paper, the effects of freeze-thaw cycles (FTCs) on the geotechnical (thermal, hydraulic, and mechanical) properties of compost-based biocovers are investigated by column experiments. In the experiments, three columns are developed, prepared, and treated by a period of methane injection (0 FTCs) after 1 FTC and 2 FTCs in three respective stages. In addition, extensive laboratory testing is carried out on the biocover samples with regard to their thermal (thermal conductivity); hydraulic (hydraulic conductivity); and mechanical (compressibility and shear strength) and physical properties (e.g., grain size distribution, moisture content). The results show that the FTCs induced changes in a number of the geotechnical properties of the biocover. However, these changes are mostly located in the top layer of the biocover (0-15 cm). It was found that FTCs significantly increased the hydraulic conductivity of the top layer of the biocover, whereas they slightly decreased the thermal conductivity of this layer. As for mechanical and physical factors, the average grain size of the compost surface slightly decreased throughout the stages, while the friction angles of the bottom and middle layers of the compostbased biocover were not significantly affected. The results presented in this paper will contribute to better design of landfill biocovers in cold regions. [ABSTRACT FROM AUTHOR]

On the basis of a newly developed intensive hourly observational precipitation dataset, the precipitation trend of South China was investigated. Results indicate that the hourly precipitation over South China featured a significant increasing trend, particularly for the extreme precipitation category. The trend is mainly due to the increasing frequency of the precipitation events. A possible mechanism accounting for this increasing trend was proposed: the global warming may be the original forcing for the trend, through its modulation on activities of the western Pacific subtropical high, but the low-level vorticity is the most important direct trigger. [ABSTRACT FROM AUTHOR]