This report presents an assessment of global and regional impacts of climate change under six different levels of climate forcing and five plausible socio-economic scenarios which define population exposure to this change. Four of the climate forcings are based on Representative Concentration Pathways (RCPs), and produce median estimates of increase in temperature in 2100 above pre-industrial levels of 1.9°C (RCP2.6), 2.9°C (RCP4.5), 3.6°C (RCP6.0) and 5.3°C (RCP8.5). Two other new forcing pathways are used, leading to intermediate increases in temperature (median estimates 2.6°C and 4.2°C above pre-industrial levels). The five socioeconomic scenarios are taken from the Shared Socio-economic Pathways (SSPs) increasingly used in climate change assessments. Impact indicators are calculated using spatially-explicit global-scale impacts models representing impacts as a change in exposure to temperature extremes, the availability of water resources, river flooding, coastal flooding, drought and energy demands, in addition to impacts on crop suitability and ecosystems. Aggregate impacts are also expressed as a proportion of global GDP using the PAGE09 integrated climate-energy model.
