scPDSI reveals future agricultural drought hotspots in humid regions

This document examines projected changes in the severity and extent of agricultural drought across global croplands, addressing the challenges of consistently defining moisture deficits across different climatic zones. Using the self-calibrating Palmer Drought Severity Index (scPDSI) and the latest CMIP6 multi-model ensemble, it assesses changes in drought frequency, duration and intensity between a historical baseline (1980–2014) and future periods under three Shared Socioeconomic Pathways. The analysis projects that global croplands will enter mild drought by 2060, with global drought severity intensifying to 1.06 and 1.36 times historical levels in the two future periods examined.

The findings indicate substantial differences between emission scenarios. During 2050–2084, drought intensity and duration could increase by up to 29% and 370% under SSP245, while drought frequency could rise by up to 87% under SSP585. Under lower-emission scenarios, the average intensity of extreme agricultural droughts decreases by 3%, whereas under SSP585, drought-affected areas are projected to double and extreme droughts could expand from 1.4% to 12.5% of global croplands. The analysis also identifies hotspots in humid regions, where drought frequency is projected to increase more sharply, highlighting growing agricultural risks in traditionally precipitation-reliant areas.