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The concrete damages of climate change are intensifying, and adaptation efforts of actors around the world are increasing, especially in coastal regions. Recommending adaptation measures for specific regions and sectors and determining long-term strategies for mitigating global climate change is essential for reducing vulnerability to climate change. This research aims to estimate the changes in climatic parameters and thermal comfort zones to determine concrete targets and offer suggestions for sectors affected by possible changes. The changes that will occur until 2100 in the Antalya basin, which is located in the southernmost part of Türkiye and is a significant hub for agricultural production and tourism, were monitored spatially using Discomfort Index (DI) and Effective Temperature taking wind velocity (ETv). The Shared Socioeconomic Pathways (SSP): SSP 245 and SSP 585 predict that the quite cool areas prevailing in the area, according to ETv, will shrink by 24% and 46%, respectively, and the prevailing cold areas, according to DI, will shrink by 45% and 56%, respectively. By 2100, 5% of the area, according to SSP 245, and 25%, according to SSP 585, will turn into hot areas and move away from the comfort level. The fact that critical regions are areas with high vitality in terms of coastal tourism shows the need to prioritize adaptation policies. These discoveries are discussed in the context of critical issues such as water scarcity and food security, contributing to policy-making for effective management by suggesting specific adaptation measures. [ABSTRACT FROM AUTHOR]

Building public consensus about the threat of climate change is critical for enacting meaningful action to address it. To understand how Americans are changing their beliefs about climate change, research typically relies on cross-sectional survey responses. Data that is collected from the same individuals over time– panel data– provides clearer evidence about whether people’s beliefs are shifting. In this article, we investigate changes in climate beliefs among the American public using panel data from 2,135 survey respondents, analyzing opinion changes through the “Global Warming’s Six Americas” framework– an audience segmentation tool that identifies the people who are the most worried about global warming (the Alarmed) to the least worried (the Dismissive). Our findings indicate that many Americans are changing their minds about climate change and becoming more worried over time, and that these shifts correlate with changes in support for climate policy and behavioral engagement. However, these trends vary within key segments of the population and indicate that while climate communication may be shifting the beliefs of many, strategies for reaching particular audiences may need to be adapted. [ABSTRACT FROM AUTHOR]

As climate change impacts increase, communicators must engage as many audiences as possible in climate action. One potentially underrated audience is video gamers. Two-thirds of Americans play video games, and video games are a potentially effective climate change communication tool. However, little research has examined whether video gamers have unique value as a target audience for climate communication, and if they do, what might be effective ways to reach them. To address this need, we use two surveys including self-identified video game players in the United States to measure their current engagement with climate change, including through video gaming. In Study 1, a nationally representative survey in the United States (N = 1,006), we found that being a video gamer was slightly positively associated with intentions to take collective action on global warming. In Study 2, restricted to gamers in the United States (N = 2,034), we found that having more friends and family who played video games, and/or being exposed to global warming content in gaming, were also positively associated with collective action intentions. These findings were consistent even after controlling for potential confounding variables such as age, political party, and global warming attitudes. Results suggest that video gamers are a worthwhile potential audience for future climate change communication, combatting the stereotype of video gamers as disengaged or antisocial, at least in the context of climate change. Our study also identifies several potential avenues for future communication with video gamers, particularly outreach to and engagement with gaming communities. [ABSTRACT FROM AUTHOR]

During extreme heat events (EHEs) the public often learns about health protective actions through the media. Visual news coverage can act as a powerful tool to help convey complex health protective actions to the public. Despite the importance of images in helping the public understand the risk, there has been no systematic analysis to assess what images have been used by media outlets in Canada during EHEs. This paper helps to fill that gap by analyzing how the Canadian media visually communicated the risks of extreme heat to the public during the unprecedented 2021 Heat Dome. A review of thousands of online news media articles published about the 2021 Heat Dome in Canada was conducted on five subscription news databases. Overall, 845 images were coded to identify denotative, connotative, and ideological content. Only 16% of these published images implied that heat was dangerous, of which only 40% depicted people, and 46% implied human suffering. Our findings demonstrate that the majority of images used in Canadian news coverage on the 2021 Heat Dome are incompatible with, and frequently contradict, evidence-based heat protective actions. Governments, public health agencies, and other stakeholders engaged in distributing heat preparedness messaging (e.g., journalists) should prioritize improving the images of extreme heat in news coverage to align with evidence-based public health messages. With rising global temperatures due to climate change and the associated increases in the frequency and intensity of extreme heat events, prioritizing these actions is critically important to offset the threat posed to public health. [ABSTRACT FROM AUTHOR]

Compound dry and hot extremes are proved to be the most damaging climatic stressor to wheat thereby with grave implications for food security, thus it is critical to systematically reveal their changes under unabated global warming. In this study, we comprehensively investigate the global change in compound dry and hot days (CDHD) within dynamic wheat growing seasons during 2015–2100 under 4 socio-economic scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) based on the latest downscaled Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Our results demonstrate a notable increase in CDHD’s frequency ( CDHD f ) and severity ( CDHD s ) worldwide under all SSPs, such increase is sharper over southern Asia in winter wheat growing season, and southern Canada, northern America, Ukraine, Turkey and northern Kazakhstan in spring wheat growing season. As the top 10 wheat producer, India and America will suffer much more detrimental CDHD in their wheat growing season. Adopting a low forcing pathway will mitigate CDHD risks in up to 93.3% of wheat areas. Positive dependence between droughts and heats in wheat growing season is found over more than 74.2% of wheat areas, which will effectively promote the frequency and severity of CDHD. Global warming will dominate the increase of CDHD directly by increasing hot days and indirectly by enhancing potential evapotranspiration thereby aggravating droughts. This study helps to optimize adaptation strategies for mitigating CDHD risks on wheat production, and provides new insights and analysis paradigm for investigating future variations in compound extremes occurring within dynamic crops growing seasons. [ABSTRACT FROM AUTHOR]

Existing evidence suggests that climate change beliefs can be subject to how the issue is framed. Particularly, the choice between a "global warming" versus a "climate change" framing influenced survey responses in some previous experiments. Furthermore, since the issue of climate change has become strongly polarized politically, framing effects were found to be moderated by political identification. Nevertheless, most of these framing effects were observed in the USA and may not be generalized in other cultures. To contribute to this area of research, we embedded an experiment in nationally representative telephone surveys conducted in 30 European countries in August–September 2021. We manipulated the wording of four climate change-related questions ("global warming" vs. "climate change") and assessed treatment effects both in the full sample and separately among leftist, rightist, green, and right-wing party voters. Our results regarding climate change existence belief replicated earlier findings since existence belief was significantly higher in the climate change group. We also found that the perceived negative impact was slightly lower when the issue was framed as "climate change." In contrast, little evidence was found of people being more skeptical or less worried when asked about "global warming" compared to "climate change." In general, skepticism was higher on the political right; however, leftists, rightists, green, and right-wing voters reacted similarly to the two frames in our European sample. We consider possible explanations for the null findings and argue that the use of "climate change" framing in communication strategies promoting climate action itself will do little to lower skepticism in Europe. [ABSTRACT FROM AUTHOR]

Extreme precipitation events (EPEs) and heatwaves (HWs) can trigger floods, droughts, and other natural disasters, resulting in severe socioeconomic losses in eastern China. However, the accurate links between EPEs and HWs and future changes in these extremes are not fully resolved, which potentially impedes disaster warning and preparedness efforts. This study examines historical and future changes in summer EPEs and HWs in eastern China based on observations and model outputs from the Coupled Model Intercomparison Project Phase 6. The results show that EPEs and HWs in eastern China have increased in the past four decades and are projected to rise in the future. According to multi-model projections, the Yangtze River Basin, along with areas to its south, are expected to experience an increase in compound disasters due to HWs and EPEs. High values of the multi-year mean total population exposure to EPEs and HWs are observed in the North China Plain, Yangtze River Delta, Sichuan Basin, and southeast coast. The total population exposure to EPEs shows a decreasing trend under Shared Socioeconomic Pathway (SSP) 245 and SSP585 scenarios during 2021–2100, consistent with future population decline. However, the annual total population exposure to HWs will increase, reaching nearly 3.0 billion and 5.0 billion by the end of the century under the SSP245 and SSP585 scenarios, respectively. Within the context of global warming, the relationship between the mean-state of precipitation and maximum temperature as well as the relationship between extreme precipitation and heatwaves shift from negative correlation in the historical period to positive correlation in future projections for eastern China. [ABSTRACT FROM AUTHOR]

The summer rainfall amount over East China is expected to increase along with a strengthening of the East Asian summer monsoon in a warmer climate. However, how the seasonality of precipitation will respond to global warming remains uncertain and is closely related to monsoon circulation. Here, we project future changes in multiple intra-seasonal rainfall characteristics over East China under 1.5 °C, 2 °C, 2.5 °C, and 3 °C of global warming above pre-industrial levels based on coupled model intercomparison project phase 6 multi-model projections. Both the onset and cessation dates over South China are likely to be delayed in a warmer climate, resulting in a later shift of the rainy season. In contrast, advanced cessation dates are projected over Northeast China with high model consensus. As for rainfall characteristics within the rainy season, total rainy season rainfall is expected to increase over the whole East China domain, with remarkable enhancement of heavy rainfall intensity. Further analysis indicates that continuous warming over a 1.5 °C warmer climate is projected to further increase total rainy season rainfall and enhance heavy rainfall intensity, with a magnitude at least twice as large with additional warming of 0.5 to 1.5 °C. Also, changes in cessation dates over South and Northeast China are projected to be enhanced significantly. These results together indicate the vital need to slow down global warming to reduce potential adverse impacts on agricultural and socioeconomic development. [ABSTRACT FROM AUTHOR]

The protection and sustainable use of environmental resources is one of the most salient tasks in Arctic regional governance, given that the region is a particularly fragile zone threatened by global warming and polar pollution. In recent years, as the People’s Republic of China has significantly increased its economic presence in the High North, whether and how Beijing’s Arctic engagement has influenced its efforts to prevent further climatic change associated with global warming and the accumulation of toxic substances are particularly important questions in the study of Arctic politics and global environmental governance. Borrowing insights from the costly signaling literature, this article presents an investigation of these questions. Contrary to the popular “Western-based” perspective that Beijing’s Arctic involvement will inevitably exaggerate human-induced environmental hazards, I argue that China’s pursuit to integrate itself into Arctic affairs and foster a responsible great power image incentivizes it to pledge more ambitious environmental policies as a costly signal to demonstrate that the rising power is willing to adhere to the Arctic’s existing norms and rules instead of challenging the status quo. Thus, China’s engagement can contribute to environmental governance and sustainable development in the Arctic region. Relying on a set of time-series error correction models and ordinary least-square regression models, the analysis shows that China’s Arctic engagement is positively correlated with its environmental policy stringency. This research advances the understanding of the implications of under-studied state actors for Arctic sustainable development and environmental governance, suggesting that the international community can benefit from accepting China into the Arctic instead of pushing it away from the circle. [ABSTRACT FROM AUTHOR]

The human influence on precipitation during tropical cyclones due to the global warming is now well documented in the literature. Several studies have found increases in Hurricane Harvey’s total precipitation over the Greater Houston area ranging from the Clausius-Clapeyron limit of 7% to as much as 38% locally. Here we use a hydraulic model to translate these attribution statements about precipitation to statements about the resultant flooding and associated damages. We find that while the attributable increase in the total volume of flood waters is the same as the attributable increase in precipitation, the attributable increase in the total area of the flood is less. However, we also find that in the most heavily flooded parts of Houston, the local attributable increases in flood area and volume are substantially larger than the increase in total precipitation. The results of this storyline attribution analysis of the Houston flood area are used to make an intuitive best estimate of the cost of Hurricane Harvey attributable to anthropogenic global warming as thirteen billion US dollars.

Mean sea-level rise (MSLR) will induce shoreline recession, increasing the stress on coastal systems of high socio-economic and environmental values. Localized mega-nourishments are meant to alleviate erosion problems by diffusing alongshore over decades and thus feeding adjacent beaches. The 21-st century morphological evolution of the Delfland coast, where the Sand Engine mega-nourishment was built in 2011, was simulated with the Q2Dmorfo model to assess the Sand Engine capacity to protect the area against the effects of MSLR. The calibrated and validated model was forced with historical wave and sea-level data and MSLR projections until 2100 corresponding to different Representative Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5). Results show that the Sand Engine diffusive trend will continue in forthcoming decades, with the feeding effect to adjacent beaches being less noticeable from 2050 onward. Superimposed to this alongshore diffusion, MSLR causes the shoreline to recede because of both passive-flooding and a net offshore sediment transport produced by wave reshaping and gravity. The existing feeding asymmetry enforces more sediment transport to the NE than to the SW, causing the former to remain stable whilst the SW shoreline retreats significantly, especially from 2050 onward. Sediment from the Sand Engine does not reach the beaches located more than 6 km to the SW, with a strong shoreline and profile recession in that area, as well as dune erosion. The uncertainties in the results are dominated by those related to the free model parameters up to 2050 whilst uncertainties in MSLR projections prevail from 2050 to 2100. [ABSTRACT FROM AUTHOR]

Mitigating the negative impacts of anthropogenic climate change is among the most serious and pressing challenges facing the global community. Despite the severity of the issue, there seems to be a lack of attention paid to climate change in our daily lives. Yet, climate change-related information can capture observers’ attention, and when attention is drawn to a particular environmental risk, the perceived severity of this attended risk is enhanced. The question then is whether attention to climate change-related information can be modified or enhanced. Here, we report the results of two experiments using single-session attention bias modification training procedures designed to increase attentional focus on climate change-related information. In Experiment 1, attention training to emotionally positive images of climate change (e.g., potential solutions such as windmills and solar panels) increased attention to these images, but not emotionally negative images of climate change (e.g., air pollution, natural disasters, and melting ice). In Experiment 2, this effect was replicated. In addition, Experiment 2 revealed that training to emotionally negative images of climate change increased attention to negative images of climate change, and there was a trend for this enhanced attention to generalize to positive images of climate change. Furthermore, attention training towards negative images of climate change enhanced self-reported levels of concern about climate change. Collectively, our results suggest that attention training can increase the allocation of attention to climate change-related information and, under certain training conditions, concern for climate change increases. [ABSTRACT FROM AUTHOR]

Americans increasingly accept that global warming is happening and a serious threat. Using secondary data from national probability surveys of the US adult population and preregistered hypotheses, we explore how and why Americans self-report changing their minds about global warming. Common reasons included learning more about the issue, hearing or seeing the effects of global warming, and personally experiencing its effects. We tested these reasons, as well as additional factors known to influence global warming opinion, including perceptions of social norms, media attention, and exposure to extreme weather, to assess their relative strength in predicting self-reported opinion change. As expected, perceived experience with global warming—particularly vicarious experience or seeing/hearing others experience its effects—emerged as a top correlate, even while statistically controlling for perceptions of social norms and attention to partisan-leaning media like Fox News. Perceived personal experience was a stronger correlate of self-reported opinion change among Republicans, whereas learning more about global warming was a stronger correlate among Democrats. Also as expected, perceiving social norms supportive of climate action was associated with positive self-reported opinion change, particularly among Republicans. Further, attention to the Fox News Channel was associated with negative self-reported opinion change but only among Republicans. Although this research is exploratory and uses self-reported data, it suggests that personalizing and localizing the threat of climate change, and enhancing the norm that most people support action, may be important factors to investigate in future longitudinal research on public opinion change and communication strategies. [ABSTRACT FROM AUTHOR]

Winter chill accumulation is critical for the productivity and profitability of perennial tree fruit systems. Several studies have quantified the impacts of global warming on chill accumulation in the warmer production regions of the world, where insufficient chill events occur and their frequency is increasing. In contrast, we focus on a region with relatively cold winters–the Pacific Northwest United States (PNW)–where insufficient chill events are currently absent, and quantify the potential for introduction of these risks under climate change. Our results show spatial variation within the PNW, with chill accumulation projected to increase in some areas but decrease in others. There was also spatiotemporal variation in the driving factors of changes to chill accumulation. Even with decreases in chill accumulation, there are likely minimal issues with insufficient chill accumulation. However, delayed chill accumulation in combination with advances in the onset of heat accumulation can potentially shift the region from one where spring phenology is primarily forcing-driven to one where interaction between chilling and forcing processes become important. These interactions might create production risks for varieties with high chill requirements, post mid-21st century under high emissions scenarios. Future work should focus on understanding, modeling, and projecting responses across these overlapping chilling and forcing processes. Additionally, given significant spatial differences across a relatively small geographic range, it is also critical to understand and model these dynamics at a local landscape resolution for regions such as the PNW. [ABSTRACT FROM AUTHOR]

Quantifying seasonally varying temperature and precipitation changes is important, particularly in relatively dry regions that are highly vulnerable to climate change. The ERA5 dataset is used here to examine long-term (1979–2020) near-surface temperature and precipitation changes and to understand the driving mechanisms for precipitation changes over Southwest Asia in different seasons. Precipitation and its changes are also analysed based on the CRU dataset. Significant warming trends with strong seasonal and regional differences are identified over Southwest Asia, with the greatest warming trend in spring, followed in decreasing order by winter, summer, and autumn. Mountain temperatures have also increased much faster than other regions in Southwest Asia, particularly in winter and spring. Based on both ERA5 and CRU, precipitation has significantly decreased over parts of southwestern and eastern Iran and southwestern Pakistan in winter but has significantly increased over the Caucasus in spring. Precipitation has not changed significantly over Southwest Asia in summer, while it has significantly increased over parts of Saudi Arabia in autumn. As the CRU dataset only covers land areas, analysis based on ERA5 indicates that precipitation has significantly decreased and increased over the Oman Sea in winter and the Persian Gulf in autumn, respectively. Wind speeds between 400 and 100 hPa levels and mean sea level pressure (MSLP) are also analysed during the period 1979–2020. The subtropical jet has risen significantly over eastern parts of Southwest Asia (55–65∘E) in autumn. In winter, the jet has shifted poleward, which resulted in robust decreasing precipitation trends over most parts of Iran and southwestern Pakistan. Over northwestern Iran, however, precipitation has increased in winter in response to a significant decrease in MSLP. In autumn, an equatorward shift of the jet has been accompanied by a significant decrease in MSLP and an increase in precipitation at lower latitudes (20–37∘N) of Southwest Asia. [ABSTRACT FROM AUTHOR]

This paper provides an assessment of Article 4.1 of the Paris Agreement on climate; the main goal of which is to provide guidance on how “to achieve the long-term temperature goal set out in Article 2”. Paraphrasing, Article 4.1 says that, to achieve this end, we should decrease greenhouse gas (GHG) emissions so that net anthropogenic GHG emissions fall to zero in the second half of this century. To aggregate net GHG emissions, 100-year global warming potentials (GWP-100) are commonly used to convert non-CO2 emissions to equivalent CO2 emissions. The GWP-scaling method is tested using methane as an example. The temperature projections using GWP-100 scaling are shown to be seriously in error. This throws doubt on the use of GWP-100 scaling to estimate net GHG emissions. An alternative method to determine the net-zero point for GHG emissions based on radiative forcing is derived, where the net-zero point is identified with the maximum of GHG forcing. This shows that, to meet the Article 2 warming goal, the net-zero point for GHG emissions needs to be reached as early as 2036, much sooner than in the Article 4.1 window. Other scientific problems in Article 4.1 that further undermine its purpose to guide efforts to achieve the Article 2 temperature targets are discussed. [ABSTRACT FROM AUTHOR]

The treatment of uncertainty in climate-change science is dominated by the far-reaching influence of the 'frequentist' tradition in statistics, which interprets uncertainty in terms of sampling statistics and emphasizes p-values and statistical significance. This is the normative standard in the journals where most climate-change science is published. Yet a sampling distribution is not always meaningful (there is only one planet Earth). Moreover, scientific statements about climate change are hypotheses, and the frequentist tradition has no way of expressing the uncertainty of a hypothesis. As a result, in climate-change science, there is generally a disconnect between physical reasoning and statistical practice. This paper explores how the frequentist statistical methods used in climate-change science can be embedded within the more general framework of probability theory, which is based on very simple logical principles. In this way, the physical reasoning represented in scientific hypotheses, which underpins climate-change science, can be brought into statistical practice in a transparent and logically rigorous way. The principles are illustrated through three examples of controversial scientific topics: the alleged global warming hiatus, Arctic-midlatitude linkages, and extreme event attribution. These examples show how the principles can be applied, in order to develop better scientific practice. "La théorie des probabilités n'est que le bon sens reduit au calcul." (Pierre-Simon Laplace, Essai Philosophiques sur les Probabilités, 1819). "It is sometimes considered a paradox that the answer depends not only on the observations but on the question; it should be a platitude." (Harold Jeffreys, Theory of Probability, 1st edition, 1939). [ABSTRACT FROM AUTHOR]

Twenty years ago, the Arctic was more resilient than now as sea ice was three times thicker than today. Heavier and more persistent sea ice provided a buffer against the influence of short-term climate fluctuations. Sea ice/atmospheric interactions now point to revisiting the concept of abrupt change. The recent decade has seen Arctic extreme events in climate and ecosystems including some events beyond previous records that imply increased future uncertaintly. While their numbers may increase, the distribution of the type, location, and timing of extreme events are less predictable. Recent processes include albedo shifts and increased sensitivity of sea ice to storms in marginal seas. Such new extremes include Greenland ice mass loss, sea ice as thin and mobile, coastal erosion, springtime snow loss, permafrost thaw, wildfires, and bottom to top ecosystem reorganizations, a consilience of impacts. One cause for such events is due to natural variability in a wavy tropospheric jet stream and polar vortex displacements, interacting with ongoing Arctic Amplification: temperature increases, sea ice loss, and permafrost thaw. This connecting hypothesis is validated by the variability of rare events matching interannual and spatial variability of weather. A proposed way forward for adaptation planning is through narrative/scenario approaches. Unless CO2 emissions are reduced, further multiple types of Arctic extremes are expected in the next decades with environmental and societal impacts spreading through the Arctic and beyond. [ABSTRACT FROM AUTHOR]

This is an extended editors’ commentary on the topical collection “Historical and recent change in extreme climate over East Asia”, which collects a total of 15 papers related to the change and variability of extreme climate events in East Asia over the last few hundreds years. The extreme climate events are broadly classified into three categories: temperature and extreme warmth/coldness, precipitation and floods/droughts and western North Pacific typhoons. This commentary briefly summarizes the main findings presented in each paper in this topical collection, and outlines the implications of these findings for monitoring, detecting and modeling of regional climate change and for studying climate change impacts and adaptability. It also assesses the uncertainties of these studies, as well as the remaining knowledge gaps that should be filled in the future. One solid conclusion we can draw from these studies is that there was a marked decadal to multi-decadal variability of extreme climate events in East Asia in recent history, and the extreme events as observed during the last decades of the instrumental era were still within the range of natural variability except for some of those related to temperature. More severe and enduring droughts occurred in the early 20 th century or the earlier periods of history, frequently leading to great famines in northern China. Uncertainties remain in reconstructing historical extreme climate events and analyzing the early instrumental records. Further research could focus on the improvement of methodology in proxy based reconstruction of multi-decadal variations of surface air temperature and precipitation/drought, the recovery, digitization, calibration and verification of the early instrumental records, and the mechanisms of the observed multi-decadal variability of extreme climate in the region. [ABSTRACT FROM AUTHOR]

The intensification of soil moisture drought events is an expected consequence of anthropogenic global warming. However, the implication of 1.5–3 °C global warming on these events remains unknown over North Africa and the Sahel region, where soil moisture plays a crucial role in food security that largely depends on rainfed agriculture. Here, using a multi-model ensemble from the Inter-Sectoral Impact Model Intercomparison Project phase 2b, we estimate the changes in the spatiotemporal characteristics of soil moisture drought events under increased global mean temperature. A 3 °C global warming results in multi-year (up to 19 years) mega-drought events over North Africa compared to a maximum drought duration of 12 years under the 1.5 °C Paris Agreement target. These events are projected to transform from historically severe droughts into exceptional droughts and extend over an area that is 32% larger under 3 °C compared to that under 1.5 °C. Global warming also leads to a high intensification of Sahelian drought extremes, in particular, their duration (from 24 to 82 months between 1.5 and 3 °C) over the western parts and their severity everywhere. Even though the results highlight substantial uncertainties arising from climate forcing and impact models, the projections indicate a tendency toward unprecedented exacerbation of soil moisture droughts that could pose serious threats to food security of North African and Sahelian societies in the absence of effective mitigation and adaptation. [ABSTRACT FROM AUTHOR]

Future changes in the mean, maximum, and minimum surface temperature over Europe are investigated according to CMIP6 future climate projections. All the temperature variables are projected to increase across Europe particularly in northern and southernmost latitudes, where according to SSP5-8.5 the warming can reach 2–3 (5–6) °C at the middle (end) of the current century. The warming is particularly strong in Northern (Mediterranean) areas in winter (summer) seasons. The occurrence of hot days (mean temperature > 30 °C) is projected to increase in all southern Europe by the end of the century (> 40–60 days/year), particularly in the southern parts of the Iberian Peninsula and Turkey. Increases in the occurrence of very hot days (maximum temperature > 40 °C) are projected in the central-southern areas of the Iberian Peninsula (30–40 days/year) and southern Turkey (> 50 days/year) in the end of the century. Tropical nights are expected to increase throughout the century in all Europe (except the northernmost latitudes), particularly at southern Europe for the 2081–2100 period (50–80 nights/year). Frost days (minimum temperature < 0 °C) are expected to occur less in all Europe towards the end of the century, with less than 50–70 days/year in central Europe and even less in Scandinavia and north-eastern Russia. [ABSTRACT FROM AUTHOR]

High impact weather events such as extreme temperatures or rainfall can cause significant disruption across the UK affecting sectors such as health, transport, agriculture and energy. In this study we draw on the latest set of UK climate projections, UKCP, to examine metrics relating to high-impact weather over the UK and how these change with different levels of future global warming from 1.5 °C to 4 °C above pre-industrial. The changes to these hazards show increases in the frequency of extremely hot days and nights, with a UK average increase in hot days of between 5 and 39 days per year between 1.5 °C and 4 °C of global warming. Projections indicate an increase in cooling degree days of 134–627% and an increase in growing degree days of 19–60% between 1.5 °C and 4 °C of global warming. Extremely hot nights, which are currently rare, are emerging as more common occurrences. The frequency of high daily temperatures and rainfall increase systematically, while the frequency of very cold conditions (based on days where temperatures fall below 0 °C) is shown to decrease by 10 to 49 days per year. A reduction in heating degree days, of 11–32% between 1.5 °C and 4 °C of warming, is projected. Levels of daily rainfall, which currently relate to increased risk of river flooding, are shown to increase across the country, with increases of days with high impact levels of rainfall occurring by 1 to 8 days per year between 1.5 °C and 4 °C of warming. Average drought severity is projected to increase for 3-, 6-, 12- and 36-month-long droughts. The largest changes in the severity of the 12-month drought are between −3 and +19% between 1.5 °C and 4 °C of warming and for 36-month drought between −2 and +54% between 1.5 °C and 4 °C of warming. The projected future changes in high impact weather from this study will enable the characterization of climate risks and ultimately be able to better inform adaptation planning in different sectors to support the increase in resilience of the UK to future climate variability and change. [ABSTRACT FROM AUTHOR]

While the US Congress has repeatedly failed to pass the national legislation to address climate change over the years, there has been much more progress among state and local governments. Is this progress on climate change policy at the subnational level merely a reflection of the dominance of the Democratic Party in certain regions of the country, or does it reflect successful bipartisan action? In this essay, we present novel evidence from two surveys of subnational policymakers, conducted in 2015 and 2017, to demonstrate that there is widespread bipartisan agreement among Republican and Democrat policymakers at the subnational level about (1) the existence of global warming and (2) what to do about it. Specifically, a majority in both parties believe global warming is happening and support the use of renewable energy mandates—rather than cap-and-trade, carbon tax, or emissions standards—to address the problem. [ABSTRACT FROM AUTHOR]

In the era when human activities can fundamentally alter the planetary climate system, a stable climate is a global commons. However, the need to develop the economy to sustain the growing human population poses the Climate Commons Dilemma. Although citizens may need to support policies that forgo their country's economic growth, they may instead be motivated to grow their economy while freeriding on others' efforts to mitigate the ongoing climate change. To examine how to resolve the climate commons dilemma, we constructed a Climate Commons Game (CCG), an experimental analogue of the climate commons dilemma that embeds a simple model of the effects of economic activities on global temperature rise and its eventual adverse effects on the economy. The game includes multiple economic units, and each participant is tasked to manage one economic unit while keeping global temperature rise to a sustainable level. In two experiments, we show that people can manage the climate system and their economies better when they regarded the goal of environmentally sustainable economic growth as a singular global goal that all economic units collectively pursue rather than a goal to be achieved by each unit individually. In addition, beliefs that everyone shares the knowledge about the climate system help the group coordinate their economic activities better to mitigate global warming in the CCG. However, we also found that the resolution of the climate commons dilemma came at the cost of exacerbating inequality among the economic units in the current constrains of the CCG. [ABSTRACT FROM AUTHOR]

Individuals living in every region of the world are increasingly vulnerable to negative health outcomes due to extreme heat exposure. Children, in particular, may face long-term consequences associated with heat stress that affect their educational attainment and later life health and well-being. Retrospective individual-level analyses are useful for determining the effects of extreme heat exposure on health outcomes. Typically, future risk is inferred by extrapolating these effects using future warming scenarios that are applied uniformly over space and time without consideration of topographical or climatological gradients. We propose an alternative approach using a stochastic weather generator. This approach employs a 1 °C warming scenario to produce an ensemble of plausible future weather scenarios, and subsequently a distribution of future health risks. We focus on the effect of global warming on fetal development as measured by birth weight in Ethiopia. We demonstrate that predicted changes in birth weight are sensitive to the evolution of temperatures not quantified in a uniform warming scenario. Distributions of predicted changes in birth weight vary in magnitude and variability depending on geographic and socioeconomic region. We present these distributions alongside results from the uniform warming scenario and discuss the spatiotemporal variability of these predicted changes. [ABSTRACT FROM AUTHOR]

Previous studies have projected a significant role for bioenergy in decarbonizing the global economy and helping realize international climate goals such as limiting global average warming to 2 ˚C or 1.5 ˚C. However, with substantial variability in bioenergy results and significant concerns about potential environmental and social implications, greater transparency and dedicated assessment of the underlying modeling and results and more detailed understanding of the potential role of bioenergy are needed. Stanford University's Energy Modeling Forum (EMF) initiated a 33rd study (EMF-33) to explore the viability of large-scale bioenergy as part of a comprehensive climate management strategy. This special issue presents the papers of the EMF-33 study—a multi-year inter-model comparison project designed to understand and assess global, long-run biomass supply and bioenergy deployment potentials and related uncertainties. Using a novel scenario design with independent biomass supply and bioenergy demand protocols, EMF-33 separately elucidates and explores the modeling of biomass feedstock supplies and bioenergy technologies and their deployment—revealing, comparing, and assessing the modeling that is suggesting that bioenergy could be a key climate containment strategy. This introduction provides an overview of the EMF-33 study design and the overview, thematic, and individual modeling team papers and types of insights that make up this special issue. By providing enhanced transparency and new detailed insights, we hope to inform policy dialogue about the potential role of bioenergy and facilitate new research. [ABSTRACT FROM AUTHOR]

The overlap in sources of greenhouse gas and local air pollutant emissions creates scope for policy measures to limit global warming and improve air quality simultaneously. In a first step, we derive estimates for the air pollution mortality-related component of the social cost of atmospheric release for 6 pollutants and 56 regions in the world. Combining these estimates with emission inventory data highlights that sector contributions to greenhouse gas emissions and air pollution health impacts differ widely across regions. Next, simulations of future emission pathways consistent with the 2 °C and 1.5 °C targets illustrate that strengthening climate policy ambition raises the total value of air quality co-benefits despite lower marginal co-benefits per tonne of greenhouse gas emissions abated. Finally, we use results from a multi-model ensemble to quantify and compare the value of health-related ambient air quality co-benefits of climate policy across sectors and regions. On the global level, overall air quality co-benefits range from $8 to $40 per tonne of greenhouse gases abated in 2030, with median across models and scenarios of $18/tCO2e. These results mask strong differentiation across regions and sectors, with median co-benefits from mitigation in the residential and service sectors in India exceeding $500/tCO2e. By taking a sector- and region-specific perspective, the results presented here reveal promising channels to improve human health outcomes and to ratchet up greenhouse gas reduction efforts to bridge the gap between countries' pledges and the global targets of the Paris Agreement. [ABSTRACT FROM AUTHOR]

The phenomenon of anthropogenic climate change has been identified as a threat multiplier for many human-related concerns. Carbon capture and storage (CCS) can, in combination with several other mitigation technologies, alleviate global warming by reducing carbon dioxide (CO2) emissions. Reducing climate change-related risks via CCS creates another risk, smaller in extent: the risk that some of the stored CO2 leaks out of the storage complex. This article reviews European legislation and evaluates how one of its objectives, that private liabilities of CCS-related leakage risks are not socialized, is ensured. Slight modifications of European legislation are suggested in order to prevent an indefinite liability of CCS operators in case a storage complex turns out to be unexpectedly and unavoidably prone to CO2 leakages. Official German and Hungarian financial precaution specifications are contrasted and related to this article's finding that the state budget is sufficiently hedged against the expected value of climate-related leakage compensation costs of poorly managed storage complexes if 3 to 6% of a CCS operator's emission-related revenues are diverted into a financial precaution fund. [ABSTRACT FROM AUTHOR]

Heatwaves have become more frequent and intense due to anthropogenic global warming and have serious and potentially life-threatening impacts on human health, particularly for people over 65 years old. While a range of studies examine heatwave exposures, few cover the whole globe and very few cover key areas in Africa, South America, and East Asia. By using global gridded climate reanalysis, population, and demographic data, this work analyses trends in change in exposure of vulnerable populations to heatwaves, providing global and per-country aggregate statistics. The difference between the global mean of heatwave indexes and the mean weighted by vulnerable population found that these populations are experiencing up to five times the number of heatwave days relative to the global average. The total exposures, measured in person-days of heatwave, highlight the combined effect of increased heatwaves and aging populations. In China and India, heatwave exposure increased by an average of 508 million person-days per year in the last decade. Mapping of changes per country highlighted significant exposure increases, particularly in the Middle East and in South East Asia. Major disparities were found between the heatwave exposures, country income group, and country health system capacity, thus highlighting the significant inequalities in global warming impacts and response capacities with respect to health across countries. It is therefore of prime importance that health development and response are coordinated with climate change mitigation and adaptation work. [ABSTRACT FROM AUTHOR]

Current-climate precipitation and temperature extremes have been identified by decision makers in West Africa as among the more impactful weather events causing lasting socioeconomic damage. In this article, we use a plausible future-climate scenario (RCP8.5) for the end of the twenty-first century to explore the relative commonness of such extremes under global warming. The analysis presented considers what a typical day in the future climate will feel like relative to current extrema. Across much of West Africa, we see that the typical future-climate day has maximum and minimum temperatures greater than 99.5% of currently experienced values. This finding exists for most months but is particularly pronounced during the Boreal spring and summer. The typical future precipitation event has a daily rainfall rate greater than 95% of current storms. These findings exist in both a future scenario model run with and without parameterised convection, and for many of the Coupled Model Inter-comparison Project version 5 ensemble members. Additionally, agronomic monsoon onset is projected to occur later and have greater inter-annual variability in the future. Our findings suggest far more extreme conditions in future climate over West Africa. The projected changes in temperature and precipitation could have serious socioeconomic implications, stressing the need for effective mitigation given the potential lack of adaptation pathways available to decision makers. [ABSTRACT FROM AUTHOR]

Russia is one of the largest carbon emitters in the world, possessing huge resources of both fossil fuels and zero-carbon energy sources. The Paris Agreement targets require substantial efforts to limit global warming to "well below 2 °C". Energy-economic modeling provides sound conclusions that continuation of existing energy and climate policy will lead to stabilization of energy carbon emissions in Russia at the current level in 2010–2050 (about 30% below 1990). Stronger mitigation policies could gradually reduce domestic energy CO2 emissions by 61% from 2010 to 2050 (75% below 1990). Deep decarbonization policies with even more ambitious commitments could ensure an 83% reduction in energy CO2 emissions from 2010 levels (88% below 1990) by 2050. All key sectors (energy, industries, transport, and buildings) can play a substantial role in decarbonizing the national economy. However Russia's historical reliance on domestic consumption and exports of fossil fuels creates strong barriers to decarbonization. Emission reduction costs are expected to be below 29 USD/tCO2 by 2030, 55 USD/tCO2 by 2040, and 82 USD/tCO2 by 2050 in the most ambitious decarbonization scenario. The results of this study provide insights into how Russia can enhance its ambitions to implement the Paris Agreement and contribute to global efforts toward building a climate-neutral economy by 2050. [ABSTRACT FROM AUTHOR]

Climate change is likely to negatively affect the habitats of non-human primate species. Recent research has identified a near-linear relationship between cumulative CO2 emissions, and the resulting regional and seasonal temperature increase. Here, we use this relationship to assess the potential impact that cumulative CO2 emissions could have on the ranges available to primate species. We used data from the International Union for Conservation of Nature on ranges for 426 species and subspecies of non-human primates, combined with spatial climate data from the Coupled Model Intercomparison Project Phase 5 that represent regional and seasonal temperature changes per unit CO2 emissions. Using these data, we estimated the portion of the area of each species' range where annual average temperatures exceed the Pre-industrial Seasonal Maximum Temperatures (PSMT), for cumulative CO2 emissions from 600 to 2000 billion tonnes of carbon. For the level of emissions corresponding to a 2 °C global temperature increase scenario, 26.1% of all ranges had temperatures in excess of their PSMTs, and for 8% of species, the entire current range was above their PSMT. This suggests the potential for considerable loss of or compromised habitat for non-human primates on a global scale, as a result of the emergence of climate conditions that are outside of the scope of historical experience for many species. Our results point to key priorities for conservation efforts, as well as the need for future research on strategies to increase the resilience of vulnerable local non-human primate populations. [ABSTRACT FROM AUTHOR]

For centuries, traditional high-altitude oases in Oman have depended on the cultivation of deciduous fruit trees. This study explores the effects of climate change on winter chill (estimated as Chilling Hours—CH and Chill Portions—CP), a prerequisite to overcoming dormancy and initiating flowering, in three Omani oases. The results are compared with findings from an earlier study which reported a decrease in the numbers of CH in high-elevation oases by an average of 1.2–9.5 CH year−1 between 1983 and 2008. Location-specific weather data were obtained by merging 15 years of in situ recordings with 28 years of observations from an official weather station near the top of the investigated watershed. Between 1991 and 2018, scenarios of the past few decades show chill reductions by 75, 35 and 18% when estimated in CP at the oases of Masayrat ar Ruwajah (1030 m a.s.l.), Qasha' (1640 m a.s.l.), and Al 'Ayn (1900 m a.s.l.), respectively. Over the course of the twenty-first century, the lowest-elevation oasis at Masayrat ar Ruwajah is projected to lose virtually all winter chill, whereas, despite significant chill losses, conditions are expected to remain viable for some of the currently grown species in the higher-elevation oases. These projected changes will compromise the cultivation of temperate fruit trees in the near future, affecting the sustainability of Omani oases. Our methods support results from earlier work performed at these locations and provide an updated procedure for assessing climate change effects on temperature-dependent systems. [ABSTRACT FROM AUTHOR]

Since global warming between 2 and 4.9 °C by 2100 is unlikely to be avoided, humans will have to live with and adapt to the impacts of climate change. Migration has long been touted as a strategy for adapting to climate change, but there is limited understanding of which aspects of climate change will have greatest influence on peoples' decision to move somewhere they consider safer or stay somewhere safe. Here, we present results from two online surveys about mobility decisions from one low (Philippines) and one high (Australia) income country within the Asia-Pacific region with similar vulnerabilities to natural hazards. Online surveys with about 1100 respondents each were conducted in both countries. Results showed that natural hazards played a strong role in the mix of reasons for mobility, particularly in the Philippines. Sudden onset hazards had the greatest influence. Results of ordered probit models showed that the perception of personal damage from hazards was strongly positively associated with mobility decisions of respondents in both countries. Mobility decisions of people in Australia were further influenced by their experience with the specific hazards: those with greater experience of slow onset hazards were more likely, and those who had experience with sudden hazards less likely, to consider these when moving or staying somewhere. People in Australia might only react to sudden onset hazards with temporary relocation since experience had shown that they can adapt to them. This suggests that slow onset climate change related impacts such as heat waves and sea level rise, as well as environmental degradation and pollution, may have more sustained effects on long-term mobility than sudden events. In the Philippines, personal characteristics such as gender, income, and health had the greatest impact while experience with hazards had almost none. [ABSTRACT FROM AUTHOR]

The impact of climatic change on forest ecosystems has received considerable attention, but our understanding of the modulation of this impact by elevational differences and by species interaction is still limited. Here, we analyse tree-ring-based growth-climate relationships for two dominant tree species along an 800-m elevational gradient on Jeju Island, South Korea. Both species, broadleaf Quercus mongolica (QUMO) and coniferous Abies koreana (ABKO), grow at the southern end of their distributional range and they have adjacent altitudinal ranges. We use static and moving bootstrapped correlation analysis to identify the effect of recent warming on their growth. QUMO is primarily positively influenced by moisture during the previous autumn at its upper elevational distribution. Recent warming, however, has diminished this relationship, while the enhancing impact of warm and dry summer conditions on QUMO growth has increased. These recent shifts in growth-climate relationship suggest an upward migration potential for QUMO due to warming-enhanced growth at higher elevations. ABKO growth, on the contrary, is primarily reduced by high winter and summer temperatures. This negative relationship has become more explicit in recent decades, particularly at lower elevations. At the highest elevation, however, ABKO growth-temperature relationship has consistently become more positive in the most recent decades. In the elevational zone where ABKO and QUMO co-exist, warming plays a primary role in ABKO growth reduction, while QUMO growth increases and thus induces a potential upward migration of QUMO. This combined effect can lead to population decline of ABKO. Our results significantly enhance our understanding of the impact of climate warming on two interacting species and provide information necessary for adaptation strategies to preserve declining ABKO populations. [ABSTRACT FROM AUTHOR]

Using Hadley Global Environment Model 2 - Earth System and Max Planck Institute Earth System Model simulations, we assess the impact of global warming and stratospheric geoengineering on deciduous fruit production in Himachal Pradesh (the second-largest apple-producing state in India). The impacts have been assessed for the Representative Concentration Pathways 4.5 (RCP4.5) global warming scenario, and a corresponding geoengineered scenario (G3) from the Geoengineering Model Intercomparison Project, in which stratospheric aerosols are increased for 50 years from 2020 through 2069 to balance the global warming radiative forcing, and then aerosol precursor emissions are terminated. We used the period 2055–2069 (with the largest geoengineering forcing) and the period 2075–2089 (beginning 5 years into the termination phase) and evaluated winter chill and growing season heat accumulation. We found that although stratospheric geoengineering would be able to suppress the increase in temperature under an RCP4.5 scenario to some extent during both switch-on and switch-off periods, if the geoengineering was terminated, the rate of temperature increase would be higher than RCP4.5. The agroclimatically suitable area is projected to shift northeastwards (to higher elevations) under RCP4.5 as well as G3 during both periods. However, during the switched on period, geoengineering would restrict the shift, and areas of Shimla and Mandi districts (most suitable under the current climate) would not be lost due to global warming. Even during the switched off period, before the climate returned to RCP4.5 levels, the above areas would, although to a lesser extent, have reduced harmful climate effects from global warming. However, the area of suitable land (the intersection of soil and agroclimatic suitability) would decrease in both periods for RCP4.5 as well as G3, because as more high-elevation regions become agroclimatically suitable, they do not have suitable soils to support cultivation. Geoengineering could benefit deciduous fruit production by reducing the intensity of global warming; however, if geoengineering was terminated abruptly, the rate of change in temperature would be quite high. This could lead to a rapid change in land suitability and might result in total crop failure in a shorter period compared to RCP4.5. [ABSTRACT FROM AUTHOR]

Changes in the frequency of cold and warm synoptic weather types within eastern North America indicate the occurrence of a cool season climate shift in the late 1990s. This aligns with the timing of shifts toward earlier spring ice out on freshwater lakes within the region and less frequent cold air mass passage over the North American Great Lakes. While a preliminary shift occurred in the early 1980s, a pronounced shift toward more frequent warm weather types during November through April occurred after 1997, when prominent warming of the lower atmosphere over the region began. The late 1990s' climate shift appears linked to middle atmospheric circulation change associated with phase changes for two influential low-frequency climate teleconnections originating within the Atlantic and Pacific Oceans, the Atlantic Multidecadal Oscillation and the Interdecadal Pacific Oscillation. The climate shift, approximately 20 years after warming within the global climate system commenced, further illustrates the importance of climate system variability within anthropogenically driven climate change. [ABSTRACT FROM AUTHOR]

The uncertainty language framework used by the Intergovernmental Panel on Climate Change (IPCC) is designed to encourage the consistent characterization and communication of uncertainty between chapters, working groups, and reports. However, the framework has not been updated since 2010, despite criticism that it was applied inconsistently in the Fifth Assessment Report (AR5) and that the distinctions between the framework's three language scales remain unclear. This article presents a mixed-methods analysis of the application and underlying interpretation of the uncertainty language framework by IPCC authors in the three special reports published since AR5. First, I present an analysis of uncertainty language term usage in three recent special reports: Global Warming of 1.5°C (SR15), Climate Change and Land (SRCCL), and The Ocean and Cryosphere in a Changing Climate (SROCC). The language usage analysis highlights how many of the trends identified in previous reports—like the significant increase in the use of confidence terms—have carried forward into the special reports. These observed trends, along with ongoing debates in the literature on how to interpret the framework's three language scales, inform an analysis of IPCC author experiences interpreting and implementing the framework. This discussion is informed by interviews with IPCC authors. Lastly, I propose several recommendations for clarifying the IPCC uncertainty language framework to address persistent sources of confusion highlighted by the authors. [ABSTRACT FROM AUTHOR]

Global warming will disproportionately affect people of color (e.g., Latinos). Previous research has found that Latinos in the USA are more engaged with global warming than are non-Latino Whites, in part, because they are more likely to perceive it as a serious risk. It was unclear, however, what factors most strongly explain Latinos' elevated perceptions of risk. This study uses two parallel, nationally representative surveys of Latino and non-Latino White Americans to investigate these different levels of risk perception. Mediation analyses indicate that Latinos' greater risk perceptions may be explained by (in order of magnitude) their stronger pro-climate injunctive social norms and egalitarian worldviews, stronger identification with the Democratic party, more frequent communication with family outside the USA, greater harm from environmental hazards, stronger descriptive norms, and a weaker individualist worldview. These findings help inform strategies for communicating with different subgroups of Americans that have different global warming risk perceptions. [ABSTRACT FROM AUTHOR]

Four bias correction methods, i.e., gamma cumulative distribution function (GamCDF), quantile–quantile adjustment (QQadj), equidistant cumulative probability distribution function (CDF) matching (EDCDF), and transform CDF (CDF-t), to read are applied to five daily precipitation datasets over China produced by LMDZ4-regional that was nested into five global climate models (GCMs), BCC-CSM1-1m, CNRM-CM5, FGOALS-g2, IPSL-CM5A-MR, and MPI-ESM-MR, respectively. A unified mathematical framework can be used to define the four bias correction methods, which helps understanding their natures and essences for identifying the most reliable probability distributions of projected climate. CDF-t is shown to be the best bias correction method based on a comprehensive evaluation of different precipitation indices. Future precipitation projections corresponding to the global warming levels of 1.5 °C and 2 °C under RCP8.5 were obtained using the bias correction methods. The multi-method and multi-model ensemble characteristics allow to explore the spreading of projections, considered a surrogate of climate projection uncertainty, and to attribute such uncertainties to different sources. It was found that the spread among bias correction methods is smaller than that among dynamical downscaling simulations. The four bias correction methods, with CDF-t at the top, all reduce the spread among the downscaled results. Future projection using CDF-t is thus considered having higher credibility. [ABSTRACT FROM AUTHOR]

Weather and climate hazards cause too many fatalities each year. These weather and climate hazards are projected to increase in frequency and intensity due to global warming. Here, we use a disaster database to investigate continentally aggregated fatality data for trends. We also examine whether modes of climate variability affect the propensity of fatalities. Furthermore, we quantify fatality risk by computing effective return periods which depend on modes of climate variability. We find statistically significant increasing trends for heat waves and floods for worldwide aggregated data. Significant trends occur in the number of fatalities in Asia where fatalities due to heat waves and floods are increasing, while storm-related fatalities are decreasing. However, when normalized by population size, the trends are no longer significant. Furthermore, the number of fatalities can be well described probabilistically by an extreme value distribution, a generalized Pareto distribution (GPD). Based on the GPD, we evaluate covariates which affect the number of fatalities aggregated over all hazard types. For this purpose, we evaluate combinations of modes of climate variability and socio-economic indicators as covariates. We find no evidence for a significant direct impact from socio-economic indicators; however, we find significant evidence for the impact from modes of climate variability on the number of fatalities. The important modes of climate variability affecting the number of fatalities are tropical cyclone activity, modes of sea surface temperature and atmospheric teleconnection patterns. This offers the potential of predictability of the number of fatalities given that most of these climate modes are predictable on seasonal to inter-annual time scales. [ABSTRACT FROM AUTHOR]

We assess uncertainties in projecting future changes in extreme storm surge height (SSH) based on typhoon data extracted from ensemble experiment results with four sea surface temperature (SST) conditions and three global warming scenarios using a single atmospheric global climate model. In particular, this study focus on typhoons passing around the Korean Peninsula (KP) defined as the region of 32 to 40° N and 122 to 132° E. It is predicted the number of the typhoons affecting the KP will decrease by 4~73% while their strength will increase by 0.8~1.4% under the given future conditions. The locations of genesis and lysis of the typhoons are expected to be shifted towards the northwest and northeast for all ensemble experiment conditions, respectively. However, the extent of their change varies depending on the future SST and global warming conditions. Storm surge simulations were carried out by using predicted typhoon data as an external force. It is found that future SST patterns and climate warming scenarios affect future typhoon characteristics, which influences values of extreme SSH and locations of the vulnerable area to storm surge under the future climate conditions. In particular, the values of extreme SSH and the locations of the vulnerable area to storm surge appear to be strongly influenced by both pathway and frequency of intense typhoons. [ABSTRACT FROM AUTHOR]

Coastal engineering is an important measure in coping with coastal risks. With global warming and sea level rising, the sustainable adaptation of the low-lying areas becomes urgent. An in-depth understanding of the relationship between coastal engineering and environmental changes can help improve the adaptation capability for climate change. Here, we use historical documents and synthesis approach to examine coastal engineering evolution on the Jiangsu coast, the largest lowland area along China's coastlines, and explore its response to local sea level and land use changes. The results show that coastal engineering here experienced a long-term period centered on sea-dike construction, with a shift from primary function of storm surge prevention since the eleventh century, towards a green coastal engineering approach in recent years. On the century scale, there was a close connection between local sea level change and coastal engineering change, while on the ten-year scale, population dynamics and land use changes were the key driving factors. Since the future climate and sea level change magnitude will be beyond what has been observed on the Jiangsu coast, it would be sensible to define a "critical time" that divides the near future and remote future. On such a basis, a strategic plan for the remote future may be formulated to prepare for the critical time when inevitable inundation occurs, and a second strategic plan may be adopted for the near future, to buy time for the coastal communities to make necessary preparations and at the same time to continue to use the resources. For the "near future," a green coastal engineering approach (in combination with the experiences gained from the Jiangsu coast) should be developed to provide a low cost, high efficiency technique for coastal defense schemes. The thoughts outlined above may be applicable also to a number of low-lying coastal regions of developing countries. [ABSTRACT FROM AUTHOR]

Global warming is projected to intensify during the twenty-first century. Yet, only few studies investigate how global warming could be perceived by future populations. Here, we propose an assessment of how climate change could be perceived by combining climatological indicators. We analyse extremes of temperature (T99) and simplified Wet-Bulb Globe Temperature (WBGT99), a heat stress index assessing the combined effect of elevated temperature and humidity on the human body. The speed of change is defined for each year as the difference between the previous 20 years and the twenty upcoming years (i.e. with a moving baseline), and we assess how these speeds emerge from each last 20-year interannual variability. Using a set of 12 CMIP5 models, speeds of change of T99 and WBGT99 in 2080 are both twice as fast compared with current speeds in mid-latitudes, and by up to four times faster in the tropics under the RCP8.5 scenario. Warming accelerations are thus similar for T99 and WBGT99. However, these speeds in tropical regions in 2080 are projected to be 2.3 times larger than the last 20-year interannual variability for WBGT99, and only 1.5 to 1.8 times larger for T99. According to the models, the WBGT99 intensification will be more emergent from the recent year-to-year variability than the T99 warming. This analysis suggests that the accelerated warming of heat extremes will be felt more strongly by populations than current changes for RCP8.5, and that this evolution will be more perceived in heat stress than in temperature, particularly within the tropics. [ABSTRACT FROM AUTHOR]

East-Central Asia is one of the most vulnerable and sensitive regions to climate change, and the variability of extreme precipitation attracts great attention due to the large population and the importance of its economy. Here, three special runs with the Community Earth System Model (CESM) are used to project the changes in representative extreme precipitation indices (Rx1day, Rx5day, R95p, SDII) over East-Central Asia under the 1.5 °C and 2 °C Paris Agreement limits. The results indicate that Rx1day and Rx5day will increase by 28% and 15%, respectively, under the 1.5 °C warming level relative to the historical period (1971–2000). Most areas over East-Central Asia are projected to experience an accelerated increase in response to a further 0.5 °C warming. Specifically, humid areas (HAs) are projected to experience a greater increase in R95p annual days and area fraction, whereas arid and semiarid areas (ASAs) may have threefold higher risks. The proportion of extreme precipitation in total will increase ~10% in most HAs in response to the 0.5 °C additional warming. Holding global warming at 1.5 °C instead of 2 °C reduces the occurrence of R95p annual days by ~3 days/year in humid areas and ~1 day/year in ASAs. For SDII, most HAs will experience 0.2–0.6 mm/day and 0.2–0.4 mm/day increases in 1.5 °C or 2 °C warming limits, especially in Southeast China and the Himalayas. Therefore, limiting global warming to under 1.5 °C is beneficial to reducing the occurrence and associated impact of precipitation extremes in East-Central Asia. [ABSTRACT FROM AUTHOR]

Temporary stratospheric aerosol injection (SAI) using sulphate compounds could help to mitigate some of the adverse and irreversible impacts of global warming. Among the risks and uncertainties of SAI, the development of a delivery system presents an appreciable technical challenge. Early studies indicate that specialised aircraft appear the most feasible (McClelan et al., Aurora Flight Sciences, 2010; Smith and Wagner, Environ Res Lett 13(12), 2018). Yet, their technical design characteristics, financial cost of deployment, and emissions have yet to be studied in detail. Therefore, these topics are examined in this two- part study. This first part outlines a set of injection scenarios and proposes a detailed, feasible aircraft design. Part 2 considers the resulting financial cost and equivalent CO2 emissions spanned by the scenarios and aircraft. Our injection scenarios comprise the direct injection of H2SO4 vapour over a range of possible dispersion rates and an SO2 injection scenario for comparison. To accommodate the extreme demands of delivering large payloads to high altitudes, a coupled optimisation procedure is used to design the system. This results in an unmanned aircraft configuration featuring a large, slender, strut-braced wing and four custom turbofan engines. The aircraft is designed to carry high-temperature H2SO4, which is evaporated prior to injection into a single outboard engine plume. Optimised flight profiles are produced for each injection scenario, all involving an initial climb to an outgoing dispersion leg at 20 km altitude, followed by a return dispersion leg at a higher altitude of 20.5 km. All the scenarios considered are found to be technologically and logistically attainable. However, the results demonstrate that achieving high engine plume dispersion rates is of principal importance for containing the scale of SAI delivery systems based on direct H2SO4 injection, and to keep these competitive with systems based on SO2 injection. [ABSTRACT FROM AUTHOR]

Livestock is a significant contributor to global anthropogenic emissions of methane, a short-lived greenhouse gas that is responsible for about 20% of the warming induced by greenhouse gases since pre-industrial times. India is a major contributor to these emissions, and its demand for livestock products is continually increasing in response to both growth in incomes and in population. We estimate methane emissions from livestock in India by estimating the demand for milk and milk products using countrywide representative consumption data over the period 1983–2012. We find that the average annual growth rate of methane emissions from dairy cattle is about twice as large (2.4%) as current estimates that do not take into account the economic factors that influence livestock demand. The difference in growth rates translates to an almost 40% difference in forecasted emissions from dairy cattle by 2050. Our findings suggest that, in a rapidly changing economic environment, current forecasts of greenhouse gas emissions from livestock may inaccurately estimate emissions since they fail to consider the economics governing it. We also estimate emissions under different scenarios, in terms of milk price trajectories and livestock composition. The changes in price do not alter our results significantly but the transition to crossbred animals in livestock drastically reduces future methane emissions from milk production. [ABSTRACT FROM AUTHOR]

Grazing systems emit greenhouse gases, which can, under specific agro-ecological conditions, be partly or entirely offset by soil carbon sequestration. However, any sequestration is time-limited, reversible, and at a global level outweighed by emissions from grazing systems. Thus, grazing systems are globally a net contributor to climate change and the time scale of key processes needs to be factored into any mitigation efforts. Failing to do so leads to unrealistic expectations of soil carbon management in grazing systems as a mitigation strategy. Protecting the large carbon stocks in grazing lands is also essential in order to avoid further climate change from additional CO2 release. Despite the time-limited and reversible nature of soil carbon sequestration in grazing lands, sequestration should be promoted in cases where it delivers environmental and agronomic benefits as well as for its potential, particularly on degraded land, to increase the feasibility of limiting global warming to less than 2 or preferably 1.5 °C. Some peer-reviewed sequestration estimates are of a similar order of magnitude to other food systems mitigation options over a 10–20 years period, such as reducing food loss and waste by 15% or aligning diets with current health related dietary-recommendations. However, caution should be applied to such comparisons since mitigation estimates are associated with large uncertainties and will ultimately depend on the economic cost-benefit relation, feasibility of implementation and time frame considered. [ABSTRACT FROM AUTHOR]

Guided by the Paris Agreement, the IPCC Special Report on Global Warming of 1.5 °C reported potential risks of climate change at different global warming levels (GWLs). To provide fundamental information on future temperature extremes over Southeast Asia (SEA), projected changes in temperature extreme indices are evaluated for different seasons at 1.5 °C and 2 °C GWLs against the historical reference period of 1976–2005 based on the ensemble of CORDEX simulations. Results show that the temperature indices increase significantly across the Indochina Peninsula and Maritime Continent at both GWLs except for decreasing daily temperature range (DTR) in the dry season, with more pronounced magnitudes at 2 °C GWL. Moreover, the regionally averaged ensemble medians of the indices show various changes over different subregions. At 1.5 °C and 2 °C GWLs, most pronounced increases of threshold indices. i.e. summer days (SU) and tropical nights (TR), are projected in Sumatra and Sulawesi for both wet and dry seasons. The warm spell duration (WSDI) increases generally, with strongest magnitudes for Sumatra and Sulawesi (Philippines and Sulawesi) in the wet (dry) season. On the other hand, significant increases of warm days and nights can also be observed at 2 °C GWL compared to 1.5 °C, particularly in the dry season, suggesting the high sensitivity of temperature extremes over the SEA. The projected potentially conspicuous temperature extremes under global warming of 1.5 °C and 2 °C primarily concentrate on the densely populated coastal regions of the main islands, showing the necessity of restricting global warming to 1.5 °C aiming at the eradication and reduction of regional climate stress for the human system in the developing countries over the SEA. [ABSTRACT FROM AUTHOR]