Higher probability of abrupt shift from drought to heavy rainfall in a warmer world
Abstract The abrupt shift from drought to heavy rainfall can lead to consecutive drought-flood hazards with high socioeconomic losses. However, past and future changes in such abrupt shift events remain poorly understood. Here we show that the lagged dependence of drought and heavy rainfall may double the probability of consecutive drought-flood hazards that would be expected from the independent occurrence of both hazards. The average historical probability of abrupt shift is 53% and will increase robustly with warming across mid- and high-latitude areas. Such increases may even emerge in the regions with projected decreases in both droughts and heavy rainfall events. Future droughts are more likely to terminate along with intense convection and strong water vapor convergence exceeding those in future normal periods, potentially amplifying the probability and intensity of heavy rainfall following droughts. Such rainfall intensification would seriously challenge the adaptation of global water infrastructure to rapid drought-flood cycles.