Population exposure to droughts in China under 1.5 °C global warming target

The Paris Agreement proposes a 1.5 °C target to limit the increase in global mean temperature (GMT). Studying the population exposure to droughts under this 1.5 °C target will be helpful in guiding new policies that mitigate and adapt to disaster risks under climate change. Based on simulations from the inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), the standardized precipitation evapotranspiration index (SPEI) was used to calculate drought frequencies in the reference period and 1.5 °C global warming scenario. Then population exposure was evaluated by combining drought frequency with simulated population data from shared socioeconomic pathways (SSPs). In addition, the relative importance of climate and demographic change and the cumulative probability of exposure change were analyzed. Results revealed that population exposure to droughts on the east side of the Hu line is much more than on the west side; exposure in the middle and lower reaches of the Yangtze River region is the highest and lowest in the Qinghai-Tibet region. An additional 6.97 million people will be exposed to droughts under the 1.5 °C global warming scenario relative to the reference period. Demographic change is the primary contributor to exposure (79.95 %) in the 1.5 °C global warming scenario, more than climate change (29.93 %) or the interaction effect (−9.88 %). Of the three drought intensities, mild, moderate, and extreme, moderate droughts contribute the most to exposure (63.59 %). The frequency of extreme droughts is likely to decrease (71.83 % probability), while mild and moderate droughts may increase slightly (55.17 % and 51.71 % probability, respectively) in the 1.5 °C global warming scenario.