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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. Currently, two such levels are discussed in the context of the international climate negotiations as long-term global temperature goals: a below 2 °C and a 1.5 °C limit in global-mean temperature rise above pre-industrial levels. Despite the prominence of these two temperature limits, a comprehensive assessment 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 1.5 °C and 2 °C. 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 several 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 % longer 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 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 under a 2 °C warming, which is about 10 cm lower for a 1.5 °C scenario. Our findings highlight the importance of regional differentiation to assess future climate risks as well as different vulnerabilities to incremental increases in global-mean temperature. The article provides a consistent and comprehensive assessment of existing projections and a solid foundation for future work on refining our understanding of warming-level dependent climate impacts. [ABSTRACT FROM AUTHOR]

There are many uncertainties in future climate, including how the Earth may react to different types of radiative forcing, such as CO2, aerosols, and even geoengineered changes in the amount of sunlight absorbed by Earth's surface. Here, we analyze model simulations where the climate system is subjected to an abrupt change of the solar constant by ±4%, and where the atmospheric CO2 concentration is abruptly changed to quadruple and half its preindustrial value. Using these experiments, we examine how clouds respond to changes in solar forcing, compared to CO2, and feedback on global surface temperature. The total cloud response can be decomposed into those responses driven by changes in global surface temperature, called the temperature mediated cloud feedbacks, and responses driven directly by the forcing that are independent of the global surface temperature. In this paper, we study the temperature mediated cloud changes to answer two primary questions: (a) How do temperature mediated cloud feedbacks differ in response to abrupt changes in CO2 and solar forcing? And (b) Are there symmetrical (equal and opposite) temperature mediated cloud feedbacks during global warming and global cooling? We find that temperature mediated cloud feedbacks are similar in response to increasing solar and increasing CO2 forcing, and we provide a short review of recent literature regarding the physical mechanisms responsible for these feedbacks. We also find that cloud responses to warming and cooling are not symmetric, due largely to non‐linearity introduced by phase changes in mid‐to‐high latitude low clouds and sea ice loss/formation. Plain Language Summary: As the global mean temperature changes, there are changes in cloud amount, location, and thickness, which can all impact the radiative balance of the Earth. Cloud changes driven directly by global temperature change are called temperature mediated cloud feedbacks. In this paper, we study the temperature mediated cloud feedbacks that occur in model simulations where the amount of sunlight incident upon the Earth is increased or decreased abruptly, and then held constant for 150 years. We compare the cloud changes in these experiments with experiments where the CO2 concentration is similarly increased or decreased abruptly and held constant for 150 years. In doing so we find that the temperature mediated cloud feedbacks following abrupt changes in solar radiation are characteristically similar to those occurring following CO2 increase. There are however substantial differences in the temperature mediated cloud feedbacks that occur while the climate is warming versus cooling. Key Points: The temperature mediated cloud changes and feedbacks incurred by changes in solar and CO2 forcing are similarOptical depth changes at high latitudes produce substantial differences in cloud feedbacks in cooling and warming experimentsLikewise, tropical circulations respond differently in models to cooling and warming, with a stronger change in the Walker circulation in warming experiments [ABSTRACT FROM AUTHOR]

Copyright of Urban Academy/ Kent Akademisi is the property of ICAM NETWORK and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A large amount of processes, which are physical, chemical and biological, are related to the global climate, which is the main component of climate change. These processes transform the global environment into a complicated situation. Climate change is the most large-scale and wellknown vexed question. This paper presents a Fuzzy Inference System (FIS) to predict the relationship between the causes and effects of climate change. Here, CO2 (Carbon Dioxide), Global Temperature Changes, Snow Cover, Percentage of Forestlands, Natural Forces, and Net Radiation are considered as important factors and FIS inputs while the considered FIS outputs are: Ozone Layer Changes, Arctic Ice Sheet Level, Permafrost Level, and Sea Level. The proposed FIS is tested on realistic scenarios and the results are in agreement with results from other authors' approaches. However, the use of a FIS allows to include elements of uncertainty and vagueness in the input variables considered. [ABSTRACT FROM AUTHOR]

The climate is an aggregate of the mean and variability of a range of meteorological variables, notably temperature (T) and precipitation (P). While the impacts of an increase in global mean surface temperature (GMST) are commonly quantified through changes in regional means and extreme value distributions, a concurrent shift in the shapes of the distributions of daily T and P is arguably equally important. Here, we employ a 30‐member ensemble of coupled climate model simulations (CESM1 LENS) to consistently quantify the changes of regionally and seasonally resolved probability density functions of daily T and P as function of GMST. Focusing on aggregate regions covering both populated and rural zones, we identify large regional and seasonal diversity in the probability density functions and quantify where CESM1 projects the most noticeable changes compared to the preindustrial era. As global temperature increases, Europe and the United States are projected to see a rapid reduction in wintertime cold days, and East Asia to experience a strong increase in intense summertime precipitation. Southern Africa may see a shift to a more intrinsically variable climate but with little change in mean properties. The sensitivities of Arctic and African intrinsic variability to GMST are found to be particularly high. Our results highlight the need to further quantify future changes to daily temperature and precipitation distributions as an integral part of preparing for the societal and ecological impacts of climate change and show how large ensemble simulations can be a useful tool for such research. Plain Language Summary: The weather varies naturally from day to day and between regions, seasons, and years. Ecosystems and our society are both adapted to the average weather conditions of a given place and to how variable the temperature and rainfall amounts are around that average. As the global surface temperature changes, whether through natural cycles or human interference, so may this variability. In this paper, we investigate changes to the distributions of daily temperature and rainfall for different levels of surface temperature increase. By using a large set of simulations from the same climate model, we estimate their means and shapes, currently and in the near future. We find that in parts of Europe and the United States, wintertime cold days will disappear more rapidly with global warming than hot days increase, leading to a less variable climate state. In Africa and the Arctic, however, climate conditions will rapidly transition out of the range of preindustrial variability and into a climate state not yet experienced by modern society. We emphasize that in order to prepare for the impacts of climate change, we need information about changes to average properties and to extreme events and about the potential changes to daily variability itself. Key Points: Daily temperature and precipitation distributions from CESM1 Large Ensemble are shown to be functions of region, season, and surface temperatureLarge differences are found in regional distributions, where they are particularly sensitive to surface temperature anomalyWe identify regions where global warming may rapidly shift seasonal climate away from preindustrial conditions [ABSTRACT FROM AUTHOR]

The fact of a carbon budget given commitment to limiting global-mean temperature increase to below 2 °C warming relative to pre-industrial levels makes CO2 emissions a scarce resource. This fact has significant consequences for the ethics of climate change. The paper highlights some of these consequences with respect to (a) applying principles of distributive justice to the allocation of rights to emissions and the costs of mitigation and adaptation, (b) compensation for the harms and risks of climate change, (c) radical new ideas about a place for criminal justice in tackling climate change, and (d) catastrophe ethics. [ABSTRACT FROM AUTHOR]

Given current emissions trends an increase in global temperatures in excess of 2°C is highly likely in the coming century. In this context, it seems increasingly probable that states may consider solar geoengineering as a stop-gap climate response. Solar geoengineering refers to measures that aim to alleviate some measure of global warming by intentionally increasing the amount of the sun's energy that is reflected into space. Currently the two most discussed solar geoengineering techniques involve either marine cloud brightening or dispersing aerosols in the stratosphere. These techniques could be relatively inexpensive, are within the technological capacities (after a brief period of development) of technologically-advanced countries, and could have an almost immediate impact on temperatures. Yet, while solar geoengineering might potentially be utilised to manage some climate-linked security threats, it itself would create new security challenges. Consequently, this paper explores potential international security implications for Australia if a regional state, or group of states, initiates a solar geoengineering program. We conclude that since solar geoengineering is unlikely to become a first-order international issue, disputation over solar geoengineering will likely reflect, or act as a proxy for, wider patterns of state interaction. However, scenarios in which China and the United States take different positions, or in which there are divisions among regional powers, such as Indonesia, Malaysia, India and Singapore would pose the greatest threat to Australia's national security. [ABSTRACT FROM AUTHOR]

Germination is a high-risk phase in a plant's life cycle and is directly regulated by temperature. Seeds germinate over a range of temperatures within which there is an optimum temperature, with thresholds above and below which no germination occurs. Rapid changes in temperature associated with global warming may cause a disconnect between temperatures a seed experiences and temperatures over which germination can occur. This paper explores the temperature dimension of the germination niche of eight herbaceous species from South West Western Australia as part of a broader assessment of endemic native species at risk of decline under global warming. The data obtained from germination studies on a temperature gradient plate were used to populate models to predict optimum germination responses (mean time to germination, germination timing and success) under current (1950–2000 averages) and future (2070 high greenhouse gas emission) temperature scenarios. The species exhibited a mix of germination responses, often with high tolerance to high diurnal temperatures. A number of species did not reach their full potential within the experimental period, indicating the presence of dormancy not overcome due to temperature alone. Modelling revealed that for some species the opportunity for germination may decline due to rising temperatures, but for others there would be little change, though a shift in germination timing may be expected. This approach to identifying extinction risk contributes tangibly to efforts to predict plant responses to environmental change and can help prioritize species for management actions, direct limited resources towards further investigations and supplement bioclimatic modelling. [ABSTRACT FROM AUTHOR]

As the global temperature is on the rise due to global warming, the issue of climate change is indeed a hot topic among the climate scientists and policy-makers worldwide. Claiming anthropogenic emissions as the primary cause of the prevailing climate change, every human activity is now under heavy scrutiny. Among others, mining is one of the fundamental activities which caters to the supply of raw materials to other basic industries and fulfils most of the energy needs of the human race and is believed to be a major contributor to the anthropogenic emissions. The present paper discusses a few case studies conducted in some Indian mines to estimate their respective carbon emissions. The accounting of carbon emissions due to mining activities is called as 'greenhouse gas inventory'. A brief look over the GHG inventory of some mines provides a succinct idea about contribution of mining industry to global emissions. The results highlight that emissions from mining industry are significant and cannot be overlooked. Thus it is required to develop clean technology to be implemented in mines to lower its emissions. [ABSTRACT FROM AUTHOR]

Tropical glaciers are extremely sensitive to a warming climate. In this paper, the evolution of the remaining tropical glaciers in Australasia (Irian Jaya, Indonesia) during the period 1988-2015 was quantified. Landsat series images, a digital elevation model from SRTM, and previously published data were used. Estimated total glacier area in 1988, 1993, 1997 and 2004 was 3.85 km2±0.13 km2, 3.01 km2±0.08 km2, 2.49 km2±0.07 km2 and 1.725 km2 ±0.042 km2, respectively. Only 0.58 km2±0.016 km2 glacierized area remained in 2015 in Puncak Jaya, which is about 84.9% loss in just 27 years. If this rate continued, the remaining tropical glaciers in Australasia would disappear in the 2020s. Timeseries analysis of climate variables showed significant positive trends in air temperature (0.009°C per year) and relative humidity (0.43% per year) but no considerable tendency was observed for precipitation. Warming climate together with mining activities would accelerate loss of glacier coverage in this region. [ABSTRACT FROM AUTHOR]

The Report: Intergovernmental Panel on Climate Change (IPCC) set a goal global warming of 1.5°C on global temperature change. Extreme climate changes have increased the demand for electricity consumption by people and enterprises. In fact, China's total power generation in 2019 exceeded 25% of the world's amount, and its thermal power generation accounted for more than 70%. Although past research on electricity efficiency seldom discusses the issue of climate change, the topic still remains important. This research thus considers extreme temperature days (climate change variable) as exogenous variable and uses the Two-Stage Meta Under exogenous undesirable EBM model to examine power efficiency in China. The results are as follows. (1) In the west only Qinghai's GDP, CO2, PM2.5, and electricity consumption have technology gap ratio (TGR) efficiency values of 1 in the 5 years. (2) China's electricity consumption has the same trend with the TGR efficiency of CO2 and is higher than PM2.5. (3) The national overall efficiency, meta overall efficiency, and TGR overall efficiency are the worst in China's west region. [ABSTRACT FROM AUTHOR]

The article focuses on the widening wealth gap and increasing pressures on Environmental standards and practices. Topics discussed include positive impacts of a moderate global temperature rise overall were outweighed by negative effects, negatives of global climate change outweighing the positives to be seen as the temperature pass the 1.1 degree Celsius global warming threshold according to economist Richard Tol.

The major cause of global warming is greenhouse gases (GHGs). Carbon dioxide (CO2) is the key GHG contributing to environmental pollution and global warming. Overall climatic conditions are changing with global temperatures rising and the level of greenhouse gases increase in the atmosphere. This is of serious concern as this climatic change will have dire consequences for crops, human health, ecological balance and biodiversity. Climatic changes and imbalance in ecology can be ascribed to an increase in carbon-dioxide emissions in the environment. South Africa being a developing economy is at the thirteenth position in carbon-dioxide emissions. It is also one of the developing countries that top in consumption of fossil fuels. It is important to forecast future carbon-dioxide emissions for South Africa so that suitable sustainability policies can be framed and measures can be taken at the right time. Annual time series data of South Africa from the time period 1980 to 2016, has been used in this study to develop autoregressive integrated moving average (ARIMA) model to predict CO2 emissions for the period of 2015–2027. It is forecasted by the use of the ARIMA model that carbon-dioxide emissions will rise at a constant rate in the next ten years in South Africa. This study will add a new dimension to existing literature and will provide a base for framing feasible environmental policies. [ABSTRACT FROM AUTHOR]

Global warming is among the important environmental problems of the earth. The present research aims to study temperature variations around the world. For this purpose, the monthly temperature data of 178 points from the NOAA site were studied from 1950 to 2019. In this study, the temperature changes were investigated in terms of its increase, decrease, and significance level by the Mann–Kendall method. Geographic Information System (GIS) and interpolation methods were used to determine the changes in temperature in global warming maps. According to the obtained results, except for 3.8% of the designated area, other parts of the world show change toward warmer conditions. Overall, the world's land temperature has increased by 1.08℃ during the study period. Also, about 85% of the designated area shows moderate and severe hazardous conditions in terms of global warming. The spatial analysis showed higher change and hazardous conditions for global warming in mid-longitude and high-latitude close to both poles. [ABSTRACT FROM AUTHOR]

The agricultural sector in Poland is of considerable social and economic importance for the nation. Climate variability and change are of primary relevance to this largely climate-dependent sector. Changes in seven temperature-related agroclimatic indices (lengths of the growing season and of the frost-free season, days of occurrence of the last spring frost and of the first autumn frost; and annual sums of growing degree-days for three values of temperature threshold) in Poland in 1951-2010 are examined. As expected, they generally correspond to the overwhelming and ubiquitous warming. Many, but not all, detected trends are statistically significant. However, for some indices, strong natural variability overshadows eventual trends. Projections of temperature-related agroclimatic indices for the future, based on regional climate models, are also discussed. [ABSTRACT FROM AUTHOR]

There is low confidence in projections of Antarctic sea ice area (SIA), due to deficiencies in climate model sea ice processes. Ensemble regression techniques can help to reduce this uncertainty. We investigate relationships between SIA climatology and 21st century change in the Coupled Model Intercomparison Project, phase 6 (CMIP6) multi‐model ensemble. In summer, under a strong forcing scenario, each model loses the majority of its sea ice. Therefore, models with greater historical SIA exhibit greater reductions, so the observed climatology of SIA strongly constrains projections. Ensemble spread in historical summer SIA is smaller than in CMIP phase 5 (CMIP5), and CMIP6 gives a more robust constraint on future SIA. In winter, by 2100 under a strong forcing scenario, 40% of SIA disappears on average, and ensemble spread in historical mean SIA explains approximately half the spread in projected change. A greater winter ice loss in CMIP6 than CMIP5 is explained by the higher climate sensitivities of some CMIP6 models. Plain Language Summary: Antarctic sea ice area is important for ecosystems, human activity, and for the dynamics of the atmosphere and ocean. However, major climate change assessments such as the Intergovernmental Panel on Climate Change Sixth Assessment Report have placed little confidence in projections of Antarctic sea ice area. This is because climate models struggle to simulate many aspects of sea ice area as observed by satellites. However, not all models should be treated equally. Models with relatively more sea ice area in the recent past project greater losses in the future, especially in summer. This suggests that models with historical sea ice area closest to what we have observed may be more reliable in their future simulations. We use this information in a simple statistical model to show that, firstly, the newest climate models largely show near‐total sea ice loss in summer by the end of the 21st century, which was not universally true for older climate models. Secondly, newer climate models lose more winter sea ice than their predecessors in the same time period, which is related to the known greater global warming response to given greenhouse gas concentrations in the newer models. Key Points: We compare Coupled Model Intercomparison Project (CMIP), phase 5 and the CMIP, phase 6 (CMIP6) projections of Antarctic sea ice loss, assessing drivers of uncertainty and the robustness of projectionsUnder strong forcing, CMIP6 models lose most Antarctic summer sea ice by 2100, so projections are constrained by historical climatologyIncreased winter sea ice loss in CMIP6 is related to increased equilibrium climate sensitivity [ABSTRACT FROM AUTHOR]

There are heated debates on the existence of the global warming slowdown during the early twenty-first century. Although efforts have been made to clarify or reconcile the controversy over this issue, it is not explicitly addressed, restricting the understanding of global temperature change particularly under the background of increasing greenhouse gas concentrations. Here, using extensive temperature datasets, we comprehensively reexamine the existence of the slowdown under all existing definitions during all decadal-scale periods spanning 1990–2017. Results show that the short-term linear trend–dependent definitions of slowdown make its identification severely suffer from the period selection bias, which largely explains the controversy over its existence. Also, the controversy is further aggravated by the significant impacts of the differences between various datasets on the recent temperature trend and the different baselines for measuring slowdown prescribed by various definitions. However, when the focus is shifted from specific periods to the probability of slowdown events, we find the probability is significantly higher in the 2000s than in the 1990s, regardless of which definition and dataset are adopted. This supports a slowdown during the early twenty-first century relative to the warming surge in the late twentieth century, despite higher greenhouse gas concentrations. Furthermore, we demonstrate that this decadal-scale slowdown is not incompatible with the centennial-scale anthropogenic warming trend, which has been accelerating since 1850 and never pauses or slows. This work partly reconciles the controversy over the existence of the warming slowdown and the discrepancy between the slowdown and anthropogenic warming. [ABSTRACT FROM AUTHOR]

A key goal of the 2015 Paris Climate Agreement is to keep global mean temperature change at 2°C and if possible under 1.5°C by the end of the century. To investigate the likelihood of achieving this target, we calculate the year of exceedance of a given global warming threshold (GWT) temperature across 32 CMIP6 models for Shared Socioeconomic Pathway (SSP) and radiative forcing combinations included in the Tier 1 ScenarioMIP simulations. Threshold exceedance year calculations reveal that a majority of CMIP6 models project warming beyond 2°C by the end of the century under every scenario or pathway apart from the lowest emission scenarios considered, SSP1–1.9 and SSP1–2.6, which is largely a function of the ScenarioMIP experiment design. The U.K. Earth System Model (UKESM1) ScenarioMIP projections are analyzed in detail to assess the regional and seasonal variations in climate at different warming levels. The warming signal emerging by midcentury is identified as significant and distinct from internal climate variability in all scenarios considered and includes warming summers in the Mediterranean, drying in the Amazon, and heavier Indian monsoons. Arctic sea ice depletion results in prominent amplification of warming and tropical warming patterns emerge that are distinct from interannual variability. Climate changes projected for a 2°C warmer world are in almost all cases exacerbated with further global warming (e.g., to a 4°C warmer world). Significance Statement: In this study, we look into changes occurring in climate due to global warming by analyzing data from the latest global climate models to see when the Earth will warm by 2° or 4°C, compared to preindustrial temperatures. We then use the UKESM1 climate model to identify regions on Earth where significant climate change is simulated in the future and discuss possible reasons for these changes. Simulations from this model also show that regions such as the Mediterranean, Amazon forests, and tropical countries are likely to see significant changes in climate impacting human lives. Future work to study the regional changes in greater detail will help us improve climate policies to protect society. [ABSTRACT FROM AUTHOR]

When the climate system is forced, for example, by the emission of greenhouse gases, it responds on multiple time scales. As temperatures rise, feedback processes might intensify or weaken. Such state dependencies cannot be fully captured with common linear regression techniques that relate feedback strengths linearly to changes in the global mean temperature. Hence, transient changes are difficult to track and it becomes easy to underestimate future warming this way. Here, we present a multivariate and spatial framework that facilitates the dissection of climate feedbacks over time scales. Using this framework, information on the composition of projected transient future climates and feedback strengths can be obtained. The new framework is illustrated using the Community Earth System Model version 2. Plain Language Summary: When the Earth warms, the internal processes of the climate system change. This can lead to additional warming, forming a feedback loop. For instance, as the ice melts due to increased temperatures, less solar radiation gets reflected back to outer space, causing temperatures to rise even more. To properly understand and assess (future) climatic changes, it is, therefore, necessary to quantify these so‐called climate feedbacks and track how they change over time. However, with current techniques, it is not easy to explicitly track these temporal changes, which hampers the interpretation of long‐term projections of the future climate state and easily leads to systematic underestimation of future (committed) warming. Here, we present a new feedback framework that can capture the temporal evolution of climate feedbacks. Consequently, a better insight into the development of a (projected) future climate is obtained, because not only global mean temperatures can be tracked, but also the temporal change in individual climate feedbacks, including their spatial distribution. Key Points: A multivariate climate feedback framework is introduced that takes into account the transient state dependency of climate feedbacksUsing the new framework, changes in feedback processes can be analyzed per time scale and temporal evolution can be trackedWithin the framework, it is possible to create transient and equilibrium projections of (the spatial patterns of) climate feedbacks [ABSTRACT FROM AUTHOR]

The unexpected global warming slowdown during 1998–2013 challenges the existing scientific understanding of global temperature change mechanisms, and thus the simulation and prediction ability of state-of-the-art climate models since most models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) cannot simulate it. Here, we examine whether the new-generation climate models in CMIP6 can reproduce the recent global warming slowdown, and further evaluate their capacities for simulating key-scale natural variabilities which are the most likely causes of the slowdown. The results show that although the CMIP6 models present some encouraging improvements when compared with CMIP5, most of them still fail to reproduce the warming slowdown. They considerably overestimate the warming rate observed in 1998–2013, exhibiting an obvious warming acceleration rather than the observed deceleration. This is probably associated with their deficiencies in simulating the distinct temperature change signals from the human-induced long-term warming trend and or the three crucial natural variabilities at interannual, interdecadal, and multidecadal scales. In contrast, the 4 models that can successfully reproduce the slowdown show relatively high skills in simulating the long-term warming trend and the three key-scale natural variabilities. Our work may provide important insight for the simulation and prediction of near-term climate changes. [ABSTRACT FROM AUTHOR]

Recent studies reporting shifts in the timing of salmonid migrations have suggested global warming to be a cause. However, the specific mechanisms underlining the evolution of earlier migration timing in salmonid fishes are unknown. In this paper, I present a hypothesis by which fishery-induced selection works to advance the timing of salmonid migration, given that the timings of migration and breeding are genetically controlled heritable traits. Although late-spawning salmon brood lines enter rivers after early-spawning brood lines, there is evidence that all brood lines arrive in coastal fishing grounds at similar times. As such, late-spawning brood lines would be fished for longer periods of time, with their increased harvest rate imposing directional selection on earlier-spawning brood lines. Thus, fisheries-induced evolution could favor the earlier timing of river entry to escape coastal fisheries. Should earlier migration timing not be an adaptation to global warming--should it be a maladaptation to fisheries-induced selection instead--then it will have a negative impact on the sustainability of salmonid resources. Des etudes recentes faisant etat de changements du moment de migrations de salmonides ont suggere que le rechauffement planetaire pourrait en etre une cause. Les mecanismes precis qui sous-tendent l'evolution vers de migrations plus hatives chez les salmonides sont toutefois inconnus. Je presente une hypothese selon laquelle la selection induite par la peche a pour effet de devancer le moment des migrations de salmonides, etant donne que le moment de la migration et le moment de la reproduction sont des caracteres heritables controles par la genetique. Bien que les lignees de saumons a reproduction tardive entrent dans les rivieres apres les lignees a reproduction hative, des indices portent a croire que toutes les lignees arrivent dans les lieux de peche cotiers a peu pres en meme temps. Ainsi, les lignees a reproduction tardive feraient l'objet de peches plus longues, leurs plus hauts taux de prises imposant une selection directionnelle sur les lignees a reproduction plus hative. Ainsi, l'evolution induite par la peche pourrait favoriser l'entree en riviere plus hative pour echapper aux peches cotieres. Si le devancement du moment de la migration ne s'avere pas etre une adaptation au rechauffement planetaire, mais plutot une mauvaise adaptation a la selection induite par la peche, il aura alors une incidence negative sur la perennite des ressources de salmonides. [Traduit par la Redaction], Introduction A major consequence of climate change is the phenological shift in life-history events in organisms. Although flowering time of plants, breeding and migration time of animals, and timing of [...]

The excessive burning of the fossil fuels has caused severe global climatic changes such as increasing the global temperature, causing initiation of the wild fire, rising the sea level, increasing the floods, storms, amount of rain and snow. One of the effective global mitigation strategies is sequestration of huge quantity of CO2 deep below the ground level for a long period of time. An important issue is to ensure the permanency and safety of the sequestration process due to the associated pore-pressure buildup. It is necessary to have correct estimates of the pore-pressure buildup, ground uplift and re-activation of any existing fault during the process of CO2 injection and long-term storage. In this investigation, the effects of reservoir size and boundary conditions are investigated by means of geomechanical modeling of the deep Biyadh sandstone reservoir in Saudi Arabia. Currently, carbon dioxide is not injected into the actual Biyadh reservoir. In this investigative modeling, CO2 is injected for an injection period of ten years using a single injection well at the center of the reservoir. The developed modeling scheme for a single injection well has been extended further to include multiple injection wells. For multiple injection wells, the reservoir size and locations of injection wells are varied to evaluate their effect on the pore-pressure buildup and ground uplift. The reservoir stability analysis has been performed using Mohr–Coulomb failure criterion for both small and large reservoir models, with the same injection parameters. The simulation results demonstrated that pressure buildup and ground uplift are relatively higher for reservoirs with small sizes and closed boundaries; while in the case of large sizes and open boundaries, the pore-pressure buildup and ground uplift are relatively lower. Moreover, the effect of the reservoir size and boundary conditions on the reactivation of faults during CO2 injection has been evaluated. The stability analysis performed in this study shows that injecting CO2 into larger size reservoir is safer as compared to smaller size reservoir. Injecting CO2 with multiple injection wells will cause pore-pressure buildup of huge magnitudes. The modeling results show that suggesting a representative volume for the reservoir during CO2 injection can under-estimate the pore-pressure buildup and fault re-activation that can cause the reservoir failure and leakage of the stored CO2. [ABSTRACT FROM AUTHOR]

Solar geoengineering that aims to offset global warming could nonetheless alter atmospheric temperature gradients and humidity and thus affect the extratropical storm tracks. Here, we first analyze climate model simulations from experiment G1 of the Geoengineering Model Intercomparison Project, in which a reduction in incoming solar radiation balances a quadrupling of CO2. The Northern Hemisphere extratropical storm track weakens by a comparable amount in G1 as it does for increased CO2 only. The Southern Hemisphere storm track also weakens in G1, in contrast to a strengthening and poleward shift for increased CO2. Using mean available potential energy, we show that the changes in zonal‐mean temperature and humidity are sufficient to explain the different responses of storm‐track intensity. We also demonstrate similar weakening in a more complex geoengineering scenario. Our results offer insight into how geoengineering affects storm tracks, highlighting the potential for geoengineering to induce novel climate changes. Plain Language Summary: Solar geoengineering refers to reflecting incoming sunlight to counteract the greenhouse effect of increased carbon dioxide concentrations and is one proposed intervention to avoid the most dramatic risks of global warming. Climate under solar geoengineering would nonetheless be meaningfully different from a baseline climate without increased carbon dioxide. The extratropical storm tracks, regions with heightened incidence of extratropical cyclones, are important components of weather and climate outside of the tropics. In simulations with global climate models, we find that the storm track in the Northern Hemisphere is similarly weakened in a solar geoengineering scenario with little change in global mean temperature as in a global warming scenario. The storm track in the Southern Hemisphere also weakens in the geoengineering scenario in contrast to a strengthening with global warming. The weakening of the storm tracks in the geoengineering scenario is partly related to a weakening of the pole‐to‐equator temperature gradient in both hemispheres. This means that reflecting incoming sunlight may not prevent changes in the strength of extratropical cyclones in the Northern Hemisphere and may overcorrect in the Southern Hemisphere. Key Points: Northern Hemisphere extratropical storm track weakens in response to increased CO2 even with the use of solar geoengineeringSouthern Hemisphere extratropical storm track also weakens in a solar geoengineering scenario but strengthens under global warmingStorm‐track intensity changes in all cases are related to changes in mean temperature structure and moisture [ABSTRACT FROM AUTHOR]

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate changes in 2015–2100 have been simulated with the use of the INM-CM5 climate model following four scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5 (single model runs) and SSP3-7.0 (an ensemble of five model runs). Changes in the global mean temperature and spatial distribution of temperature and precipitation are analyzed. The global warming predicted by the INM-CM5 model in the scenarios considered is smaller than that in other CMIP6 models. It is shown that the temperature in the hottest summer month can rise more quickly than the seasonal mean temperature in Russia. An analysis of a change in Arctic sea ice shows no complete Arctic summer ice melting in the 21st century under any model scenario. Changes in the meridional streamfunction in atmosphere and ocean are studied. [ABSTRACT FROM AUTHOR]

Global warming projections show an anomalous temperature increase both at the Arctic surface and at lower latitudes in the upper troposphere. The Arctic amplification decreases the meridional temperature gradient, and simultaneously decreases static stability. These changes in the meridional temperature gradient and in the static stability have opposing effects on baroclinicity. The temperature increase at the upper tropospheric lower latitudes tends to increase the meridional temperature gradient and simultaneously increase static stability, which have opposing effects on baroclinicity as well. In this study, a dry idealized general circulation model with a modified Newtonian cooling scheme, which allows any chosen zonally symmetric temperature distribution to be simulated, is used to study the effect of Arctic amplification and lower-latitude upper-level warming on eddy activity. Due to the interplay between the static stability and meridional temperature gradient on atmospheric baroclinicity changes, and their opposing effect on atmospheric baroclinicity, it is found that both the Arctic amplification and lower-latitude upper-level warming could potentially lead to both decreases and increases in eddy activity, depending on the exact prescribed temperature modifications. Therefore, to understand the effect of global warming–like temperature trends on eddy activity, the zonally symmetric global warming temperature projections from state-of-the-art models are simulated. It is found that the eddy kinetic energy changes are dominated by the lower-latitude upper-level warming, which tends to weaken the eddy kinetic energy due to increased static stability. On the other hand, the eddy heat flux changes are dominated by the Arctic amplification, which tends to weaken the eddy heat flux at the lower levels. [ABSTRACT FROM AUTHOR]

Despite the monotonically rising greenhouse gas emission, global warming rate changes again and again, especially the slowdown during 1998–2013, challenging the current global temperature change mechanisms. Recently, different-scale natural climate variabilities have been individually recognized as the potential causes of global warming rate change, particularly the recent warming slowdown, but disagreements still exist on their relative importance. Here we quantify the contribution of interannual, interdecadal and multidecadal variabilities (IAV, IDV and MDV) in modulating the global warming rate during the period 1850–2017 via decomposing the global mean temperature timeseries derived from 12 datasets into several quasi-periodic fluctuations and a monotonical secular trend (ST) using the ensemble empirical mode decomposition method. Our results show that the IAV, IDV and MDV dominate the global warming rate change together, rather than one-scale variability alone. For example, during 1998–2013 both the IAV and IDV present obvious negative trends and combine to cut 59 ± 22% of global mean surface temperature (GMST) and 65 ± 38% of sea surface temperature (SST) positive trends which are caused by the steadily warming ST and the warming phase of MDV, thus causing an apparent warming slowdown during this period. Furthermore, we illustrate that the IAV, IDV and MDV mainly originate from the El Niño-Southern oscillation (ENSO), Pacific decadal oscillation (PDO) and Atlantic multidecadal oscillation (AMO), respectively. Our work partly reconciles the controversy over the importance of different-scale natural variabilities, and provides some insights for climate change attribution and prediction research. [ABSTRACT FROM AUTHOR]

The amount of additional future temperature change following a complete cessation of CO2 emissions is a measure of the unrealized warming to which we are committed due to CO2 already emitted to the atmosphere. This "zero emissions commitment" (ZEC) is also an important quantity when estimating the remaining carbon budget – a limit on the total amount of CO2 emissions consistent with limiting global mean temperature at a particular level. In the recent IPCC Special Report on Global Warming of 1.5 ∘ C, the carbon budget framework used to calculate the remaining carbon budget for 1.5 ∘ C included the assumption that the ZEC due to CO2 emissions is negligible and close to zero. Previous research has shown significant uncertainty even in the sign of the ZEC. To close this knowledge gap, we propose the Zero Emissions Commitment Model Intercomparison Project (ZECMIP), which will quantify the amount of unrealized temperature change that occurs after CO2 emissions cease and investigate the geophysical drivers behind this climate response. Quantitative information on ZEC is a key gap in our knowledge, and one that will not be addressed by currently planned CMIP6 simulations, yet it is crucial for verifying whether carbon budgets need to be adjusted to account for any unrealized temperature change resulting from past CO2 emissions. We request only one top-priority simulation from comprehensive general circulation Earth system models (ESMs) and Earth system models of intermediate complexity (EMICs) – a branch from the 1 % CO2 run with CO2 emissions set to zero at the point of 1000 PgC of total CO2 emissions in the simulation – with the possibility for additional simulations, if resources allow. ZECMIP is part of CMIP6, under joint sponsorship by C4MIP and CDRMIP, with associated experiment names to enable data submissions to the Earth System Grid Federation. All data will be published and made freely available. [ABSTRACT FROM AUTHOR]

Over the next century, the Arctic is projected to become seasonally sea ice‐free. Assessing feedback between clouds and sea ice as the Arctic loses sea ice cover is important because of clouds' radiative impacts on the Arctic surface. Here we investigate present‐day and future Arctic cloud‐sea ice relationships in a fully coupled global climate model forced by business‐as‐usual increases in greenhouse gases. Model evaluation using a lidar simulator and lidar satellite observations shows agreement between present‐day modeled and observed cloud‐sea ice relationships. Summer clouds are unaffected by sea ice variability, but more fall clouds occur over open water than over sea ice. Because the model reproduces observed cloud‐sea ice relationships and their underlying physical mechanisms, the model is used to assess future Arctic cloud‐sea ice feedback. With future sea ice loss, modeled summer cloud fraction, vertical structure, and optical depth barely change. Future sea ice loss does not influence summer clouds, but summer sea ice loss does drive fall cloud changes by increasing the amount of sunlight absorbed by the summertime ocean and the latent and sensible heat released into the atmosphere when the Sun sets in fall. The future fall boundary layer deepens and clouds become more opaque over newly open water. The future nonsummer longwave cloud radiative effect strengthens as nonsummer cloud cover increases. In summary, we find no evidence for a summer cloud‐sea ice feedback but strong evidence for a positive cloud‐sea ice feedback that emerges during nonsummer months as the Arctic warms and sea ice disappears. Key Points: No summer cloud‐sea ice feedback emerges in a global climate model in a future sea ice‐free ArcticFuture fall clouds become more opaque and the boundary layer deepens over newly open waterAnnual net Arctic cloud‐sea ice feedback is positive but the magnitude may be underestimated in this study [ABSTRACT FROM AUTHOR]

The satellite altimeter record has provided an unprecedented database for understanding sea-level rise and has recently reached a major milestone at 25 years in length. A challenge now exists in understanding its broader significance and its consequences for sea-level rise in the coming decades and beyond. A key question is whether the pattern of altimeter-era change is representative of longer-term trends driven by anthropogenic forcing. In this work, two multimember climate ensembles, the Community Earth System Model (CESM) and the Earth System Model Version 2M (ESM2M), are used to estimate patterns of forced change [also known as the forced response (FR)] and their magnitudes relative to internal variability. It is found that the spatial patterns of 1993-2018 trends in the ensembles correlate significantly with the contemporaneous FRs (0.55 ± 0.10 in the CESM and 0.61 ± 0.09 in the ESM2M) and the 1950-2100 FRs (0.43 ± 0.10 in the CESM and 0.51 ± 0.11 in the ESM2M). Unforced runs for each model show such correlations to be extremely unlikely to have arisen by chance, indicating an emergence of both the altimeter-era and long-term FRs and suggesting a similar emergence in nature. Projected patterns of the FR over the coming decades resemble those simulated during the altimeter era, suggesting a continuation of the forced pattern of change in nature in the coming decades. Notably, elevated rates of rise are projected to continue in regions that are susceptible to tropical cyclones, exacerbating associated impacts in a warming climate. [ABSTRACT FROM AUTHOR]

Historical temperature data of Palestine in the 20th century have been analysed using time series analysis to detect the warming and cooling phases. Linear regression analysis was used to identify the signs and the magnitude of the temperatures trends. Linear correlation coefficient is used to identify the strength of the relationships of the temperature with time. The warming of the first and last decades is a general feature of the monthly, seasonal and annual temperature. The strongest positive trend of 1.2°C/100 years was found in summer and spring, while autumn and winter were warmed by 0.32°C and 0.95°C/100 years respectively. The annual temperature of the last century (1901- 2000) was warmed by 0.9°C. The strongest warming trend was found in the next half of the last century, particularly from around 1970s/mid1980s onward. Annual temperature was significantly warmed by 1.1°C from 1980 onward. Seasonal warming trend from mid 1980s onward was 1.1°C for both Summer and Autumn, and 0.5°C to 0.7°C for Spring and Winter respectively. T-test was applied to validate the statistical significance of the mean temperature differences between 1901-1950 and 1951-2000. Monthly, seasonal and annual temperatures in 1951-2000 showed positive and statistically significant differences, except for a few months. There was gradual decreasing trend/cooling for February and March from 1970s onward. [ABSTRACT FROM AUTHOR]

Survey researchers often treat self-assessed understanding of climate change as a rough proxy for knowledge, which might affect what people believe about this topic. Self-assessments can be unrealistically high, however, and correlated with politics, so they deserve study in their own right. Turning the usual perspective around to view self-assessed understanding as dependent variable, problematically related to actual knowledge, casts self-assessments in a new light. Analysis of a 2016 US survey that carried a five-item test of very basic, belief-neutral but climate-relevant knowledge (such as knowing about the location of North and South Poles) finds that, at any given level of knowledge, people saying they “understand a great deal” about climate change are more likely to be older, college-educated, and male. Self-assessed understanding exhibits a U-shaped political pattern: highest among liberals and the most conservative, but lowest among moderate conservatives. Among liberal and middle-of-the-road respondents, self-assessed understanding of climate change is positively related to knowledge. Among the most conservative, however, understanding is unrelated or even negatively related to knowledge. For that group in particular, high self-assessed understanding reflects confidence in political views, rather than knowledge about the physical world. [ABSTRACT FROM AUTHOR]

As the climate changes, increasing variations in environmental factors directly influence crop cultivation at different magnitudes over a broad range of local communities worldwide. As a result, there is an urgent need to develop local impact assessments and adaptation strategies for use at local, rather than national or global, levels. In this study, we predicted the future frost damage of kiwifruit in the Jeonnam province, Korea, as a case study for the local impact assessment of climate change. This study included a series of models that integrated both the biological responses of plants and the physical influences of climatic factors. First, potential changes in the suitable area for kiwifruit cultivation under a changing climate were simulated using downscaled high resolution (1 km) climate data. Through the development of a frost‐forecasting model and linking it to a kiwifruit phenology model, we also assessed the interaction of plant and climatic factors. Because of the warming climate, the last frost date in spring occurred 13.7 days earlier in average under climate change. Nevertheless, the potential risk of spring frost damage of kiwifruit continued to exist at a similar magnitude in the future. Additional study at the county level indicated that the date of bud burst is advancing even faster than the last frost date (approximately 1 day per every decade), resulting in the increasing risk of spring frost damage for kiwifruit through 2100. In this study, the local impacts of climate change on kiwifruit frost damage were assessed using the integrated modelling approach. As such, local policy makers and stakeholders will be able to prepare more realistic adaptation strategies to cope with upcoming threats in a changing climate. In this study, the local impacts of climate change on kiwifruit frost damage in the Jeonnam Province, Korea were assessed using an integrated modelling approach. First, optimal areas for kiwifruit cultivation under a changing climate were simulated, resulting in almost 98% of lands becoming "Highly suitable" in the 2080s. In addition, through the development of a frost‐forecasting model and linking it to a kiwifruit phenology model, we found that the potential risk of spring frost damage of kiwifruit continued to exist at a similar magnitude as shown in the figure below. [ABSTRACT FROM AUTHOR]

Abstract: On interannual to decadal time scales, the climate mode with many of the strongest societal impacts is the El Niño–Southern Oscillation (ENSO). However, quantifying ENSO's changes in a warming climate remains a formidable challenge, due to both the noise arising from internal variability and the complexity of air‐sea feedbacks in the tropical Pacific Ocean. In this work, we use large (≥30‐member) ensembles of climate simulations to show that anthropogenic climate change can produce systematic increases in ENSO teleconnection strength over many land regions, driving increased interannual variability in regional temperature extremes and wildfire frequency. As the spatial character of this intensification exhibits strong land‐ocean contrasts, a causal role for land‐atmosphere feedbacks is suggested. The identified increase in variance occurs in multiple model ensembles, independent of changes in sea surface temperature variance. This suggests that in addition to changes in the overall likelihoods of heat and wildfire extremes, the variability in these events may also be a robust feature of future climate. [ABSTRACT FROM AUTHOR]

Climate change is a global phenomenon. Its impact on economic growth must therefore be analyzed in accordance with its (time-varying) common effects. We present an econometric analysis that evaluates this effect taking into account its global nature. Contrary to previous evidence that ignores the global effects, we obtain that the rising temperature has not decreased growth in real GDP per capita in the second half of the twentieth century for the world countries. However, we obtain a negative effect of rising temperatures and a positive effect of rising precipitation in poor countries. This positive effect of rising precipitation is also confirmed for hot and temperate countries. [ABSTRACT FROM AUTHOR]

We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System--biosphere, climate, and societies--and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values. [ABSTRACT FROM AUTHOR]

It has been challenging to project the tropical cyclone (TC) intensity, structure and destructive potential changes in a warming climate. Here, we compare the sensitivities of TC intensity, size and destructive potential to sea surface warming with and without a pre-storm atmospheric adjustment to an idealized state of Radiative-Convective Equilibrium (RCE). Without RCE, we find large responses of TC intensity, size and destructive potential to sea surface temperature (SST) changes, which is in line with some previous studies. However, in an environment under RCE, the TC size is almost insensitive to SST changes, and the sensitivity of intensity is also much reduced to 3% °C−1-4% °C−1. Without the pre-storm RCE adjustment, the mean destructive potential measured by the integrated power dissipation increases by about 25% °C−1 during the mature stage. However, in an environment under RCE, the sensitivity of destructive potential to sea surface warming does not change significantly. Further analyses show that the reduced response of TC intensity and size to sea surface warming under RCE can be explained by the reduced thermodynamic disequilibrium between the air boundary layer and the sea surface due to the RCE adjustment. When conducting regional-scale sea surface warming experiments for TC case studies, without any RCE adjustment the TC response is likely to be unrealistically exaggerated. The TC intensity-temperature sensitivity under RCE is very similar to those found in coupled climate model simulations. This suggests global mean intensity projections under climate change can be understood in terms of a thermodynamic response to temperature with only a minor contribution from any changes in large-scale dynamics. [ABSTRACT FROM AUTHOR]

The recent (twentieth century) and future (twenty-first century) climate evolution in the Mediterranean region is analyzed in relation to annual mean global surface temperature change. The CMIP5 (Coupled Model Intercomparison Project, Phase 5) simulations, the CRU (Climate Research Unit) observational gridded dataset, and two twentieth century reanalyzes (ECMWF, European Center for Medium range Weather Forecasts) and NOAA ESRL (National Oceanic and Atmospheric Administration-Earth System Research Laboratory) are used. These datasets to large extent agree that in the twentieth century: (a) Mediterranean regional and global temperatures have warmed at a similar rate until the 1980s and (b) decadal variability determines a large uncertainty that prevents to identify long-term links between precipitation in the Mediterranean region and global temperature. However, in the twenty-first century, as mean global temperature increases, in the Mediterranean region, precipitation will decrease at a rate around − 20 mm/K or − 4%/K and temperature will warm 20% more than the global average. Warming will be particularly large in summer (approximately 50% larger than global warming) and for the land areas located north of the basin (locally up to 100% larger than global warming). Reduction of precipitation will affect all seasons in the central and southern Mediterranean areas, with maximum reduction for winter precipitation (− 7 mm/K or − 7%/K for the southern Mediterranean region). For areas along the northern border of the Mediterranean region, reduction will be largest in summer (− 7 mm/K or − 9%/K for the whole northern Mediterranean region), while they will not experience a significant reduction of precipitation in winter. [ABSTRACT FROM AUTHOR]

Though very widely believed to be inadequate in the target it sets, the Paris Agreement is commonly thought actually to set a binding target of reducing global CO2e emissions so as to limit global warming to 2°C. Proper legal interpretation of the Agreement shows it to set no such target. It rather gives the newly industrialising countries such as China and India a permission to emit as much as they see fit. These countries have been principally responsible for the huge growth in emissions since 1990 and they will be responsible for their continued huge growth until 2030. The Paris Agreement therefore makes the policy of mitigation of global warming impossible. However, this policy has been impossible over the whole of the now more than a quarter century of international climate change policy. [ABSTRACT FROM AUTHOR]

ABSTRACT Climate change is a topic of enormous interest due to its direct impact and long-term consequences. The ongoing climate warming is triggering global impacts and it is likely to alter natural systems at the local scale, too. The observed climate variability in the Romanian Carpathians has been tackled by several researchers and the negative impact of climate change on groundwater vulnerability has also been assessed. A temporal analysis of four climate indices (De Martonne, UNEP Index, Johansson Continentality Index and Pinna Combinative Index) and crop evapotranspiration over the past 50 years was performed to understand the climate trends in the Beliş district, to estimate the effective precipitation in the area and to assess the effects of climate change on groundwater resources. Land cover data were extracted from satellite images and crop evapotranspiration data were evaluated based on field co-efficients. An examination of the climate index trends and change points was carried out using the Rodionov test. In the study area, the climate indices indicated very humid and marine climate conditions. At the same time, it was noticed that the crop evapotranspiration values increased from 1961 to 2013 and the annual effective precipitation ranged between 200-300 mm. In order to understand the impacts of climate change on groundwater resources, an innovative method was proposed using an inference matrix that combines the climate indices and effective precipitation. Based on this method, the climate indices and effective precipitation for four decades indicated a low impact of climate change on groundwater resources in the Beliş district. [ABSTRACT FROM AUTHOR]

Scholars and journalists alike interpreted “A Southern Baptist Declaration on the Environment and Climate Change”, a document released in 2008 by a group of American Southern Baptists, as evidence that American evangelicals were becoming increasingly concerned about the environment. Using the tools of textual analysis, I show that this was not the only interpretation of the document at play. While journalists and scholars understood the Declaration as addressing the need to halt climate change, for a group of key Southern Baptist signatories, the document expressed a need for Southern Baptists to engage more actively in the public environmental discourse, lest they relinquish this domain to secular and liberal voices. Critically, the latter group viewed the Declaration as compatible with climate scepticism. My analysis shows how cultural context informs climate change attitudes, while also suggesting socio-historical factors—particularly evangelicals’ embattled mentality—that may support climate change scepticism in Southern Baptist circles. [ABSTRACT FROM PUBLISHER]

Climate change poses a considerable amount of national and international security risks. While there is uncertainty surrounding the projections of climate change, it is not an excuse for delaying action. The global temperature is rising at a rapid pace, which will increasingly result in melting glaciers, heightened sea levels, heat waves, flooding, heavy rainfall, desertification, disease, scarcity of resources and ultimately, conflict. Some of these consequences, such as the melting glaciers and heightened sea levels are already prominently visible. In order to reduce the unfortunate outcomes of climate change, extensive and rapid reductions in CO2 emissions must be made. [ABSTRACT FROM AUTHOR]

Temperatures were examined at 118 stations located in the Arctic and compared to observations at 50 European stations whose records averaged 200 years and in a few cases extend to the early 1700s. Nearly all stations exhibited warming trends. For each station, the temperature relative to the average value during 1961-1990 was found. The resulting temperature change averaged over the Arctic stations was plotted. For the period 1820-2014, trends were found for the January, July and annual temperatures of 1.0, 0.0 and 0.7 °C per century, respectively. Decadal variations are evident and much of the temperature increase occurred during the 1990s. Over the past century, Siberia, Alaska and Western Canada have experienced somewhat greater warming than Eastern Canada, Greenland and Northern Europe. The temperature change experienced by the Arctic stations during the last two centuries closely tracks that found for the European stations. [ABSTRACT FROM AUTHOR]

The subsurface ocean response to anthropogenic climate forcing remains poorly characterized. From the Coupled Model Intercomparison Project (CMIP), a robust response of the lower thermocline is identified, where the warming is considerably weaker in the subtropics than in the tropics and high latitudes. The lower thermocline change is inversely proportional to the thermocline depth in the present climatology. Ocean general circulation model (OGCM) experiments show that sea surface warming is the dominant forcing for the subtropical gyre change in contrast to natural variability for which wind dominates, and the ocean response is insensitive to the spatial pattern of surface warming. An analysis based on a ventilated thermocline model shows that the pattern of the lower thermocline change can be interpreted in terms of the dynamic response to the strengthened stratification and downward heat mixing. Consequently, the subtropical gyres become intensified at the surface but weakened in the lower thermcline, consistent with results from CMIP experiments. [ABSTRACT FROM AUTHOR]

Climate change is expected to increase future temperatures, potentially resulting in reduced crop production in many key production regions. Research quantifying the complex relationship between weather variables and wheat yields is rapidly growing, and recent advances have used a variety of model specifications that differ in how temperature data are included in the statistical yield equation. A unique data set that combines Kansas wheat variety field trial outcomes for 1985-2013 with location-specific weather data is used to analyze the effect of weather on wheat yield using regression analysis. Our results indicate that the effect of temperature exposure varies across the September-May growing season. The largest drivers of yield loss are freezing temperatures in the Fall and extreme heat events in the Spring.We alsofind that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure tofreezing temperatures. Our analysis indicates that there exists a tradeoff between average (mean) yield and ability to resist extreme heat across varieties. More-recently released varieties are less able to resist heat than older lines. Our results also indicate that warming effects would be partially offset by increased rainfall in the Spring. Finally, we find that the method used to construct measures of temperature exposure matters for both the predictive performance of the regression model and the forecasted warming impacts on yields. [ABSTRACT FROM AUTHOR]

Climate change includes not only changes in mean climate but also in weather extremes. For a few prominent heatwaves and heavy precipitation events a human contribution to their occurrence has been demonstrated. Here we apply a similar framework but estimate what fraction of all globally occurring heavy precipitation and hot extremes is attributable to warming. We show that at the present-day warming of 0.85 °C about 18% of the moderate daily precipitation extremes over land are attributable to the observed temperature increase since pre-industrial times, which in turn primarily results from human influence. For 2 °C of warming the fraction of precipitation extremes attributable to human influence rises to about 40%. Likewise, today about 75% of the moderate daily hot extremes over land are attributable to warming. It is the most rare and extreme events for which the largest fraction is anthropogenic, and that contribution increases nonlinearly with further warming. The approach introduced here is robust owing to its global perspective, less sensitive to model biases than alternative methods and informative for mitigation policy, and thereby complementary to single-event attribution. Combined with information on vulnerability and exposure, it serves as a scientific basis for assessment of global risk from extreme weather, the discussion of mitigation targets, and liability considerations. [ABSTRACT FROM AUTHOR]

The comprehensive general circulation model ECHAM6 is used in a radiative-convective equilibrium configuration. It is coupled to a perfectly conducting slab. To understand the local impact of thermodynamic surface properties on the land-ocean warming contrast, the surface latent heat flux and surface heat capacity are reduced stepwise, aiming for a land-like climate. Both ocean-like and land-like RCE simulation reproduce the tropical atmosphere over ocean and land in a satisfactory manner and lead to reasonable land-ocean warming ratios. A small surface heat capacity induces a high diurnal surface temperature range which triggers precipitation during the day and decouples the free troposphere from the diurnal mean temperature. With increasing evaporation resistance, the net atmospheric cooling rate decreases because cloud base height rises, causing a reduction of precipitation. Climate sensitivity depends more on changes in evaporation resistance than on changes in surface heat capacity. A feedback analysis with the partial radiation perturbation method shows that amplified warming over idealized land can be associated with disproportional changes in the lapse rate versus the water vapor feedback. Cloud feedbacks, convective aggregation, and changes in global mean surface temperature confuse the picture. [ABSTRACT FROM AUTHOR]