Land-atmosphere feedbacks and anthropogenic greenhouse gas forcing intensify subseasonal drought-to-pluvial abrupt transitions

Abrupt transitions from drought to pluvial conditions are increasingly reported and pose substantial risks to global hydrological stability. However, their occurrence patterns, underlying mechanisms, and future trajectories remain insufficiently understood. Here, we develop a soil moisture-precipitation index to identify such subseasonal transitions using global reanalysis data and climate model projections. Globally, events occur with an average probability of about 45%, exceeding the theoretical expectation under random conditions, and are most frequent in mid-latitude monsoon regions, including South Asia, Central Europe, and the Mediterranean. Moreover, soil moisture deficits at the end of drought enhance the likelihood of strong convective precipitation by intensifying near-surface heating and atmospheric moisture convergence, especially in energy-limited climates. Under a high-emissions future, both event frequency and probability increase across more than three-quarters of global land. Greenhouse gas forcing accounts for most of the projected increases, highlighting growing risks from compound hydroclimatic extremes. Abrupt transitions from drought to extreme precipitation occur more often under higher atmospheric greenhouse gas levels, and are favored through the influence of soil moisture deficits on convective precipitation, revealed by a global assessment based on reanalysis data and climate model projections.