Future drought in CMIP6 projections and the socioeconomic impacts in China

Projections of future drought conditions under climate change are an important step in formulating the long-term climate adaptation strategies. It is therefore valuable to predict the drought conditions in China following the release of the CMIP6 (the phase six of the Coupled Model Inter-comparison Project). Thus, based on 20 global climate model simulations from CMIP6, we project China's drought conditions and its socioeconomic impacts using the self-calibrated Palmer Drought Severity Index (scPDSI). Four scenarios are considered in this analysis: SSP1-2.6 (the low-level development scenario), SSP2-4.5 (the middle-level development scenario), SSP3-7.0 (the medium to high-level development scenario) and SSP5-8.5 (the high-level development scenario). Under SSP1-2.6, we observed wetting trends over large areas of China except the arid region during 2020-2099; however, under SSP2-4.5, SSP3-7.0 and SSP5-8.5, significant drying trends are detected in the humid and temperate semi-humid region, while in other areas there are significant wetting trends. The projected drought conditions are likely to be severe with more frequent monthly occurrences and higher probability of extreme drying conditions, especially in these humid and temperate semi-humid regions under SSP3-7.0 and SSP5-8.5. Consequently, the population exposure to drought in most climatic regions will increase initially up to 2040s and gradually decrease under all the scenarios except SSP3-7.0; and the humid region will be a future hotspot where the impact of climate on population exposure to drought will be more significant. The economic exposure to drought will increase over the whole China under all four scenarios, especially in the humid and semi-humid region. Our results have important implications for future drought projections and provide a scientific evidence for developing climate change adaptation strategies and disaster prevention.