River floods are among some of the costliest natural disasters [1], but their socioeconomic impacts under contrasting warming levels remain little explored [2]. Here, using a multi-model framework, we estimate human losses, direct economic damage, and subsequent indirect impacts (welfare losses) under a range of temperature (1.5°C, 2°C, and 3°C [3]) and socioeconomic scenarios, assuming current vulnerability levels and in absence of future adaptation. At 1.5°C, depending on the socioeconomic scenario, it is found that human losses from flooding could rise by 70 to 83%, direct flood damage by 160 to 240%, with a relative welfare reduction between 0.23 to 0.29%. In a 2°C world, by contrast, the death toll is 50% higher, direct economic damage doubles, and welfare losses grow to 0.4%. Impacts are notably higher under 3C warming, but at the same time, variability between ensemble members also increases, leading to greater uncertainty regarding flood impacts at higher warming levels. Flood impacts are further shown to have uneven regional distribution, with greatest losses observed over the Asian continent at all specific warming levels. It is clear that increased adaptation and mitigation effortsperhaps through infrastructural investment [4]is needed to offset increasing river flood risk in the future.

Quantitative estimates of the economic damages of climate change usually are based on aggregate relationships linking average temperature change to loss in gross domestic product (GDP). However, there is a clear need for further detail in the regional and sectoral dimensions of impact assessments to design and prioritize adaptation strategies. New developments in regional climate modeling and physical-impact modeling in Europe allow a better exploration of those dimensions. This article quantifies the potential consequences of climate change in Europe in four market impact categories (agriculture, river floods, coastal areas, and tourism) and one nonmarket impact (human health). The methodology integrates a set of coherent, high-resolution climate change projections and physical models into an economic modeling framework. We find that if the climate of the 2080s were to occur today, the annual loss in household welfare in the European Union (EU) resulting from the four market impacts would range between 0.2-1%. If the welfare loss is assumed to be constant over time, climate change may halve the EU's annual welfare growth. Scenarios with warmer temperatures and a higher rise in sea level result in more severe economic damage. However, the results show that there are large variations across European regions. Southern Europe, the British Isles, and Central Europe North appear most sensitive to climate change. Northern Europe, on the other hand, is the only region with net economic benefits, driven mainly by the positive effects on agriculture. Coastal systems, agriculture, and river flooding are the most important of the four market impacts assessed.climate adaptation policy | climate impact and adaptation assessment | integrated assessment model | computable general equilibrium

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Extreme sea levels (ESLs) in Europe could rise by as much as one metre or more by the end of this century due to climate change. This poses significant challenges to safeguard coastal communities. Here we present a comprehensive analysis of economically efficient protection scenarios along Europe's coastlines during the present century. We employ a probabilistic framework that integrates dynamic simulations of all ESL components and flood inundation, impact modelling and a cost-benefit analysis of raising dykes. We find that at least 83% of flood damages in Europe could be avoided by elevating dykes in an economically efficient way along 23.7%-32.1% of Europe's coastline, specifically where high value conurbations exist. The European mean benefit to cost ratio of the investments varies from 8.3 to 14.9 while at country level this ranges between 1.6 and 34.3, with higher efficiencies for a scenario with high-end greenhouse gas emissions and strong socioeconomic growth.

How much will climate change damage the European economy? Which geographical areas would be the most affected? Which sectors are most vulnerable? Where and why will there be gains from climate change? How sectoral policies should be changed to consider climate impacts and adaptation? These questions are relevant for designing and prioritising adaptation strategies, as stressed by the European Commission White Paper on Adaptation (European Commission 2009). Within that context, the main motivation of the PESETA research project (Projection of Economic impacts of climate change in Sectors of the European Union based on boTtom-up Analysis) has been to contribute to a better understanding of the possible physical and economic impacts induced by climate change in Europe over the 21st century, paying particular attention to the sectoral and geographical dimensions of impacts Ciscar et al. 2011a).There are two approaches in the literature used to estimate the economic impacts of climate change. The first approach implements a top-down perspective proposing reducedform damage functions that relate climate variables to a measure of economic impact. The effect of climate change on gross domestic product (GDP) is usually a function of the average global temperature, such as in e.g. Hitz andSmith (2004) andStern (2007). Yet, this approach has some drawbacks. Firstly, estimates are based on results from the literature, derived from different, and maybe inconsistent, climate change scenarios. Secondly, only average temperature and precipitation are usually included. Other relevant climate variables and the required time-space resolution in climate data are not taken into account. Thirdly, impact estimates lack the necessary geographical resolution for assessing regional impacts and prioritising adaptation policies.A second strand of the literature has followed a bottom-up approach, where the physical effects of climate change are estimated by running high-resolution impact-specific models,