Future Evolution and Sources of Uncertainty in Global Drought Recovery Probabilities

Understanding how climate change affects the soil moisture drought recovery process is a priority to guide adaptation planning in drought management and to promote climate-resilient agriculture. A future climate scenario analysis framework was developed to project the spatiotemporal trends of global soil moisture drought and assess future changes in extreme drought recovery probabilities relative to the baseline period. Additionally, the two-factor analysis of variance approach was conducted to quantify the contributions of different uncertainty sources in climate change projections. The latest Inter-Sectoral Impact Model Intercomparison Project (ISIMIP 3b) simulations indicate that global soil moisture droughts will increase in frequency, extent, and intensity in the future. The strongest, most robust increases were projected in Amazon, central and southern Europe, southern Africa, southern China, southeastern Asia, and Oceania. Although a reduction in drought magnitude was projected in the northern high-latitudes, the recovery time and the precipitation required to terminate a drought were anticipated to increase compared to the baseline period. Compared to the baseline period, approximately 57.5% of global regions are projected to experience a decline in drought recovery probability during crop growing seasons under SSP1-2.6 scenario, particularly in northern North America, northern Europe, northwestern Asia, western Central Africa, the central Amazon basin, and southern Australia. Under SSP3-7.0 and SSP5-8.5 scenarios, this proportion will rise to 61.3% and 60.3%, respectively. The ANOVA-based assessment reveals that climate model is the dominant uncertainty source, accounting for approximately 59.5%–66.8% of the total variance. Additionally, the contributions of emission scenarios and their interactions increase as drought recovery time lengthens, particularly in Southern Northern America, Central Africa, Southern Asia, Southern South America, Southern Africa and Oceania. Although future drought recovery probability projections are associated with non-negligible uncertainties, the increasingly difficult to recover from extreme droughts at the global scale highlights the importance of taking certain measures to mitigate drought risks.