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As climate change research becomes increasingly applied, the need for actionable information is growing rapidly. A key aspect of this requirement is the representation of uncertainties. The conventional approach to representing uncertainty in physical aspects of climate change is probabilistic, based on ensembles of climate model simulations. In the face of deep uncertainties, the known limitations of this approach are becoming increasingly apparent. An alternative is thus emerging which may be called a ‘storyline’ approach. We define a storyline as a physically self-consistent unfolding of past events, or of plausible future events or pathways. No a priori probability of the storyline is assessed; emphasis is placed instead on understanding the driving factors involved, and the plausibility of those factors. We introduce a typology of four reasons for using storylines to represent uncertainty in physical aspects of climate change: (i) improving risk awareness by framing risk in an event-oriented rather than a probabilistic manner, which corresponds more directly to how people perceive and respond to risk; (ii) strengthening decision-making by allowing one to work backward from a particular vulnerability or decision point, combining climate change information with other relevant factors to address compound risk and develop appropriate stress tests; (iii) providing a physical basis for partitioning uncertainty, thereby allowing the use of more credible regional models in a conditioned manner and (iv) exploring the boundaries of plausibility, thereby guarding against false precision and surprise. Storylines also offer a powerful way of linking physical with human aspects of climate change.

Concern about the human impact of climate change has led to predictions of how people living in areas vulnerable to drought, flood, and temperature changes will respond to such events. Early studies warned that climate change would lead to dramatic increases in human migration as households became unable to adapt to the impacts of climate change. More recently, empirical studies focused on observed climate events and trends have documented how migration flows vary as a function of both the severity of the event and the ability of the household to migrate, among other factors. In this paper, we provide a systematic review of this literature, based on a conceptual framework in which climate shocks (e.g., drought, floods, or temperature extremes) affect (a) household capability to migrate, by depleting household resources necessary for migration, and (b) household vulnerability in staying, by increasing the risk that a household falls (further) into poverty. In combination, these factors help explain four key patterns seen in the empirical literature: (1) climate-induced migration is not necessarily more prevalent among poorer households; (2) climate-induced migration tends to be more prevalent for long-distance domestic moves than local or international moves; (3) slow-onset climate changes (such as droughts) are more likely to induce increased migration than rapid-onset changes (such as floods); and (4) the severity of climate shocks impacts migration in a nonlinear fashion, with impacts influenced by whether the capability or vulnerability channel dominates.

The climate crisis is an unprecedented existential threat that causes disturbing emotions, such as anxiety. Recently, Clayton and Karazsia measured climate anxiety as “a more clinically significant ‘anxious’ response to climate change” (2020, p. 9). To gain a more nuanced understanding of the phenomenon from an empirical psychological perspective, we translated the core of the Climate Anxiety Scale into German and assessed potential correlates in a large German-speaking quota sample ( N  = 1011, stratified by age and gender). Overall, people reported low levels of climate anxiety. Climate anxiety correlated positively with general anxiety and depressiveness, avoidance of climate change in everyday life, frustration of basic psychological needs, pro-environmental behavioral intentions, and policy support. It correlated negatively with different forms of climate denial and was unrelated to ideological beliefs. We were not able to replicate the two dimensions found in the original scale. Moreover, we argue that items appear to measure a general climate-related emotional impairment, rather than distinctly and comprehensively capturing climate anxiety. Thus, we encourage researchers to rework the scale and include an emotional factor in future research efforts.

The European CORDEX (EURO-CORDEX) initiative is a large voluntary effort that seeks to advance regional climate and Earth system science in Europe. As part of the World Climate Research Programme (WCRP) - Coordinated Regional Downscaling Experiment (CORDEX), it shares the broader goals of providing a model evaluation and climate projection framework and improving communication with both the General Circulation Model (GCM) and climate data user communities. EURO-CORDEX oversees the design and coordination of ongoing ensembles of regional climate projections of unprecedented size and resolution (0.11° EUR-11 and 0.44° EUR-44 domains). Additionally, the inclusion of empirical-statistical downscaling allows investigation of much larger multi-model ensembles. These complementary approaches provide a foundation for scientific studies within the climate research community and others. The value of the EURO-CORDEX ensemble is shown via numerous peer-reviewed studies and its use in the development of climate services. Evaluations of the EUR-44 and EUR-11 ensembles also show the benefits of higher resolution. However, significant challenges remain. To further advance scientific understanding, two flagship pilot studies (FPS) were initiated. The first investigates local-regional phenomena at convection-permitting scales over central Europe and the Mediterranean in collaboration with the Med-CORDEX community. The second investigates the impacts of land cover changes on European climate across spatial and temporal scales. Over the coming years, the EURO-CORDEX community looks forward to closer collaboration with other communities, new advances, supporting international initiatives such as the IPCC reports, and continuing to provide the basis for research on regional climate impacts and adaptation in Europe.

This paper presents a global scale assessment of the impact of climate change on water scarcity. Patterns of climate change from 21 Global Climate Models (GCMs) under four SRES scenarios are applied to a global hydrological model to estimate water resources across 1339 watersheds. The Water Crowding Index (WCI) and the Water Stress Index (WSI) are used to calculate exposure to increases and decreases in global water scarcity due to climate change. 1.6 (WCI) and 2.4 (WSI) billion people are estimated to be currently living within watersheds exposed to water scarcity. Using the WCI, by 2050 under the A1B scenario, 0.5 to 3.1 billion people are exposed to an increase in water scarcity due to climate change (range across 21 GCMs). This represents a higher upper-estimate than previous assessments because scenarios are constructed from a wider range of GCMs. A substantial proportion of the uncertainty in the global-scale effect of climate change on water scarcity is due to uncertainty in the estimates for South Asia and East Asia. Sensitivity to the WCI and WSI thresholds that define water scarcity can be comparable to the sensitivity to climate change pattern. More of the world will see an increase in exposure to water scarcity than a decrease due to climate change but this is not consistent across all climate change patterns. Additionally, investigation of the effects of a set of prescribed global mean temperature change scenarios show rapid increases in water scarcity due to climate change across many regions of the globe, up to 2 °C, followed by stabilisation to 4 °C.

The ensemble results of CMIP5 climate models that applied the RCP4.5 and RCP8.5 scenarios have been used to investigate climate change and temperature extremes in the Middle East and North Africa (MENA). Uncertainty evaluation of climate projections indicates good model agreement for temperature but much less for precipitation. Results imply that climate warming in the MENA is strongest in summer while elsewhere it is typically stronger in winter. The summertime warming extends the thermal low at the surface from South Asia across the Middle East over North Africa, as the hot desert climate intensifies and becomes more extreme. Observations and model calculations of the recent past consistently show increasing heat extremes, which are projected to accelerate in future. The number of warm days and nights may increase sharply. On average in the MENA, the maximum temperature during the hottest days in the recent past was about 43 °C, which could increase to about 46 °C by the middle of the century and reach almost 50 °C by the end of the century, the latter according to the RCP8.5 (business-as-usual) scenario. This will have important consequences for human health and society.

How much finance should be provided to support climate change adaptation and by whom? How should it be allocated, and on what basis? Over the years, various actors have expressed different normative expectations on climate finance. Which of these expectations are being met and which are not; why, and with what consequences? Have new norms and rules emerged, which remain contested? This article takes stock of the first 25+ years of adaptation finance under the United Nations Framework Convention on Climate Change (UNFCCC) and seeks to understand whether adaptation finance has become more justly governed and delivered over the past quarter century. We distinguish among three “eras” of adaptation finance: (1) the early years under the UNFCCC (1992–2008); (2) the Copenhagen shift (2009–2015); and (3) the post-Paris era (2016–2018). For each era, we systematically review the justice issues raised by evolving expectations and rules over the provision, distribution, and governance of adaptation finance. We conclude by outlining future perspectives for adaptation finance and their implications for climate justice.

Coffee is one of the most important globally traded commodities and substantially contributes to the livelihoods of millions of smallholders worldwide. As a climate-sensitive perennial crop, coffee is likely to be highly susceptible to changes in climate. Using a systematic approach, we explore evidence from the published academic literature of the influence of climate change and variability, specifically drought, on coffee production. A number of mostly negative impacts were reported in the current literature, including declines in coffee yield, loss of coffee-optimal areas with significant impacts on major global coffee-producing countries and growth in the distribution of pest and disease that indirectly influence coffee cultivation. Current research also identified positive effects of climate change such as increases in coffee-producing niche, particularly in areas at higher altitudes; however, whether these gains might offset losses from other production areas requires further investigation. Other advantages include increases in pollination services and the beneficial effects of elevated carbon concentration, leading to potential yield improvements. Future priorities should focus on major coffee-growing regions projected to be adversely affected by climate change, with specific attention given to potential adaptation strategies tailored to particular farming conditions such as relocation of coffee plantations to more climatically suitable areas, irrigation and agroforestry. The majority of studies were based in the Americas and concentrated on Arabica coffee. A broader spread of research is therefore required, especially for the large growing regions in Asia and for Robusta coffee, to support sustainable production of the global coffee industry.

A new high-resolution regional climate change ensemble has been established for Europe within the World Climate Research Program Coordinated Regional Downscaling Experiment (EURO-CORDEX) initiative. The first set of simulations with a horizontal resolution of 12.5 km was completed for the new emission scenarios RCP4.5 and RCP8.5 with more simulations expected to follow. The aim of this paper is to present this data set to the different communities active in regional climate modelling, impact assessment and adaptation. The EURO-CORDEX ensemble results have been compared to the SRES A1B simulation results achieved within the ENSEMBLES project. The large-scale patterns of changes in mean temperature and precipitation are similar in all three scenarios, but they differ in regional details, which can partly be related to the higher resolution in EURO-CORDEX. The results strengthen those obtained in ENSEMBLES, but need further investigations. The analysis of impact indices shows that for RCP8.5, there is a substantially larger change projected for temperature-based indices than for RCP4.5. The difference is less pronounced for precipitation-based indices. Two effects of the increased resolution can be regarded as an added value of regional climate simulations. Regional climate model simulations provide higher daily precipitation intensities, which are completely missing in the global climate model simulations, and they provide a significantly different climate change of daily precipitation intensities resulting in a smoother shift from weak to moderate and high intensities.

North Africa is considered a climate change hot spot. Existing studies either focus on the physical aspects of climate change or discuss the social ones. The present article aims to address this divide by assessing and comparing the climate change vulnerability of Algeria, Egypt, Libya, Morocco, and Tunisia and linking it to its social implications. The vulnerability assessment focuses on climate change exposure, water resources, sensitivity, and adaptive capacity. The results suggest that all countries are exposed to strong temperature increases and a high drought risk under climate change. Algeria is most vulnerable to climate change, mainly due to the country’s high sensitivity. Across North Africa, the combination of climate change and strong population growth is very likely to further aggravate the already scarce water situation. The so-called Arab Spring has shown that social unrest is partly caused by unmet basic needs of the population for food and water. Thus, climate change may become an indirect driver of social instability in North Africa. To mitigate the impact of climate change, it is important to reduce economic and livelihood dependence on rain-fed agriculture, strengthen sustainable land use practices, and increase the adaptive capacity. Further, increased regional cooperation and sub-national vulnerability assessments are needed.