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The original article has been corrected: Legends in Fig. 7 in the article and legends in Figs. 9 and 10 of Supplementary Material 1 as well as contents in columns H and J of Supplementary Material 2 have been amended to the valid results.

We project climate change induced changes in fluvial flood risks for six global warming levels between 1.5 and 4 °C by 2100, focusing on the major river basins of six countries. Daily time series of precipitation, temperature and monthly potential evapotranspiration were generated by combining monthly observations, daily reanalysis data and projected changes in the five CMIP5 GCMs also selected in the ISI-MIP fast track project. These series were then used to drive the HBV hydrological model and the CaMa-Flood hydrodynamic model to simulate river discharge and flood inundation. Our results indicate that return periods of 1 in 100-year floods in the late twentieth century (Q100-20C) are likely to decrease with warming. At 1.5 °C warming, 47%, 66%, 27%, 65%, 62% and 92% of the major basin areas in Brazil, China, Egypt, Ethiopia, Ghana and India respectively experience a decrease in the return period of Q100-20C, increasing to 54%, 81%, 28%, 82%, 86% and 96% with 4 °C warming. The decrease in return periods leads to increased number of people exposed to flood risks, particularly with 4 °C warming, where exposure in the major river basin areas in the six countries increases significantly, ranging from a doubling (China) to more than 50-fold (Egypt). Limiting warming to 1.5 °C would avoid much of these increased risks, resulting in increases ranging from 12 to 1266% for the 6 countries.

Sea-levels will rise, even with stringent climate change mitigation. Mitigation will slow the rate of rise. There is limited knowledge on how the costs of coastal protection vary with alternative global warming levels of 1.5°C to 4.0°C. Analysing six sea-level rise scenarios (0.74m to 1.09m, 50th percentile) across these warming levels, and five Shared Socioeconomic Pathways, this paper quantifies the economic costs of flooding and protection due to sea-level rise using the Dynamic Interactive Vulnerability Assessment (DIVA) modelling framework. Results are presented for World Bank income groups and five selected countries from the present to 2100. Annual sea flood damage costs without additional adaptation are more influenced by socio-economic development than sea-level rise, indicating there are opportunities to control risk with development choices. In contrast, annual sea dike investment costs are more dependent on the magnitude of sea-level rise. In terms of total costs with adaptation, upper middle, low middle and low income groups are projected to have higher relative costs as a proportion of GDP compared with high income groups. If low income countries protected now, flood costs could be reduced after 2050 and beyond. However, without further adaptation, their coasts will experience growing risks and costs leaving them increasingly reliant on emergency response measures. adaptation. Without mitigation or adaptation, greater inequalities in damage costs between income groups could result. At country level, annual sea flood damage costs without additional adaptation are projected to rapidly increase with approximately 0.2m of sea-level rise, leaving limited time to plan and adapt. SB, PG, KJ, RJ and RW were funded by the Department for Business, Energy and Industrial Strategy (BEIS) under contract UK SBS CR18083. ASA, SB, SJ, DL, RN, RT and AV were funded by the European Union’s Seventh Programme for Research, Technological Development and Demonstration under grant agreement No. 603396 (RISES-AM project).

Floods are among the most frequent and costliest natural hazards. Fluvial flood losses are expected to increase in the future, driven by population and economic growth in flood-prone areas, and exacerbated in many regions by effects of climate change on the hydrological cycle. Yet, studies assessing direct and indirect economic impacts of fluvial flooding in combination with climate change and socio-economic projections at a country level are rare. This study presents an integrated flood risk analysis framework to calculate total (direct and indirect) economic damages, with and without socio-economic development, under a range of warming levels from < 1.5 to 4 °C in Brazil, China, India, Egypt, Ethiopia, and Ghana. Direct damages are estimated by linking spatially explicit daily flood hazard data from the Catchment-based Macro-scale Floodplain (CaMa-Flood) model with country- and sector-specific depth-damage functions. These values input into an economic Input-Output model for the estimation of indirect losses. The study highlights that total fluvial flood losses are largest in China and India when expressed in absolute terms. When expressed as a share of national GDP, Egypt faces the largest total losses under both the climate change and climate change plus socio-economic development experiments. The magnitude of indirect losses also increased significantly when socio-economic development was modelled. The study highlights the importance of including socio-economic development when estimating direct and indirect flood losses, as well as the role of recovery dynamics, essential to provide a more comprehensive picture of potential losses that will be important for decision makers.

The potential impact of climate change on agriculture has been one of the most discussed topics in the literature on climate change. Although the possible impacts of climate change on crop yields have been widely studied, there remains little quantitative understanding of the heterogeneous economic responses to climate-induced crop yield changes in different economies, particularly at higher levels of warming. This study assesses the economic impacts of eight scenarios of warming, from 1.5 to 4 °C, on rice and wheat yields in China, India, Brazil, Egypt, Ghana and Ethiopia. The role of both natural and social factors in crop production is considered by coupling a statistical crop model (ClimaCrop) and a global economic model (GTAP). Changes in economic outputs, consumer and producer prices and national economic welfare are presented. The study shows marginal benefits of crop yield changes on GDP and welfare in China up to 3.5 and 3.0 °C, respectively. This is due to projected increases in rice yields which lower domestic consumer rice prices. Although at higher warming levels these trends begin to reverse. The other countries are negatively impacted due to declining crop yields, with increasing consumer prices of domestic and imported rice and wheat. GDP and welfare declines, with more severe reductions associated with the higher warming levels, particularly in India and Ethiopia. The method is beneficial as the economic outputs reflect a more in-depth picture of the response of global markets and ultimately regional consequences of agricultural impacts that will be of importance to decision makers.

The earth's climate has a profound influence on the earth's ecosystems and biodiversity. Climate change is already resulting in changes in terrestrial species distributions and phenology. It is also increasing the frequency and intensity of extreme weather events, and increases in floods, heatwaves, drought, and fire are also affecting ecosystems. If global warming is not limited to 1.5°C above preindustrial levels, future projections show large and accelerating risks to biodiversity. Effects include large scale geographic range loss of over 50% for large proportions of widespread and common species of plants, animals and insects, accelerating risks of extinction, and large-scale disruption of ecosystem functioning. Biodiversity underpins the functioning of ecosystems and its loss threatens services that ecosystems provide to humans such as flood prevention, soil conservation, water purification, crop pollination, food provision, tourism, amenity, and human wellbeing. Some types of land-based climate change mitigation methods could themselves compete with biodiversity conservation. To address these risks, climate change mitigation policies would need to be aligned with carbon sequestration in terrestrial ecosystems, by eliminating deforestation and restoring ecosystems of all types.

Climate change is projected to have significant effects on the distribution of species globally, but research into the implications in parts of Africa has been limited. Using species distribution modelling, this study models climate change-related risks to the terrestrial biodiversity (birds, mammals, reptiles, amphibians and plants) of Kenya’s economically-important and ecologically diverse Tana River Basin. Large reductions in species richness are projected with just 2°C warming (relative to preindustrial levels) with birds and plants seeing the greatest impact. Potential climate refugia for biodiversity are identified within the basin, but often overlap with areas already converted to agriculture or set aside for agricultural expansion, and the majority are outside protected areas. Similarly, some protected areas contain no projected refugia at higher levels of global warming, showing they may be insufficient to protect the basin’s biodiversity as climate changes. However, risks to biodiversity are much smaller if the Paris Agreement’s goal of limiting global warming to ‘well below 2°C’ warming, rather than 2°C only, is met. The potential for refugia for plants and animals decreases strongly with warming. For example, 82% of the basin remaining climatically suitable for at least 75% of the plants currently present at 1.5°C warming, as compared with 23% at 2°C and 3% at 4.5°C. This research provides the first assessment of the combined effects of development plans and climate change on biodiversity of the Tana River Basin, including identifying potential areas for restoration, and contributes to a greater understanding of biodiversity protection and adaptation options in Kenya.

Climate change affects life at global scales and across systems but is of special concern in areas that are disproportionately rich in biological diversity and uniqueness. Using a meta-analytical approach, we analysed >8000 risk projections of the projected impact of climate change on 273 areas of exceptional biodiversity, including terrestrial and marine environments. We found that climate change is projected to negatively impact all assessed areas, but endemic species are consistently more adversely impacted. Terrestrial endemics are projected to be 2.7 and 10 times more impacted than non-endemic natives and introduced species respectively, the latter being overall unaffected by climate change. We defined a high risk of extinction as a loss of >80% due to climate change alone. Of endemic species, 34% and 46% in terrestrial and marine ecosystems, and 100% and 84% of island and mountain species were projected to face high extinction risk respectively. A doubling of warming is projected to disproportionately increase extinction risks for endemic and non-endemic native species. Thus, reducing extinction risks requires both adaptation responses in biodiversity rich-spots and enhanced climate change mitigation.