Unequal impacts of future droughts on global croplands: contributions of climate and land-use changes across different income groups

Abstract

This study presents a global assessment of future cropland exposure to drought risks under climate change, accounting for both climate variability and land-use changes across income groups. We used SPI and SPEI to assess concurrent 3- and 6-month drought risks during major crop-growing periods, applying a copula-based method to capture joint and transitional drought events. Exposure disparities and dominant drivers were evaluated using high-resolution global cropland projections under SSP245 and SSP585 scenarios. Results show modest increases in SPI-based severe drought concurrence but substantial increases in extreme droughts, particularly under SSP585. SPEI-based projections reveal even greater risks due to temperature-driven evapotranspiration, with some exposure increases exceeding 4000%. Transitional drought risks further intensify vulnerabilities, especially in lower-middle-income countries. Climate change emerges as the dominant driver of exposure increases, while the role of land-use change diminishes. These findings underscore the urgent need for climate mitigation and targeted adaptation to safeguard global food security.