Global cropland exposure to extreme compound drought heatwave events under future climate change

Abstract

The risk of compound drought heatwave events (CDHEs) and their persistence has intensified in recent decades and is expected to increase faster in the future. Projecting future changes in the CDHEs and the area of the cropland exposed to CDHEs under different scenarios is critical for climate adaptation and sustainable development. In this study, we analyze cropland exposure to extreme CDHEs at the global and continental scales under different Shared Socioeconomic Pathways (SSPs) scenarios for the mid-term (2041–2060) and long-term (2081–2100) of the 21st century by using 14 CMIP6 GCMs and LUH2 land-use data. We find that the extreme CDHEs with high frequency are mainly located in tropical areas. The frequency of extreme CDHEs in the future will be much higher than that of the baseline period (1995–2014), and the increased frequency will be more obvious with the emissions increase. Overall, the global total cropland exposure in warm season during the 1995–2014 period will be 148.05 × 103 km2 month−1. Exposure in the mid-term and long-term will be 868.68–1801.25 and 1058.58–3887.54 × 103 km2 month−1 under the different SSP scenarios. The climate effect will be the dominant driving factor for the increase in cropland exposure. Cropland exposure to extreme CDHEs will increase on all continents, especially in Asia and Africa. Our findings provide scientific evidence of the benefit of limiting low-emission scenarios which will effectively reduce cropland exposure to CDHEs under future climate change.