On the possibility of the 2022-like spatio-temporally compounding event across the Yangtze River Valley

Abstract

During July-September 2022, heatwaves, droughts, forest fires and floods hit the Yangtze River Valley successively, constituting a spatio-temporally compounding event. Understanding its risks matters to disaster preparedness. Through searching for event analogues in single-model initial-condition large-ensemble climate simulations, we report that the 2022 unprecedentedly widespread and intense hot drought might have occurred as early as in the 1970s, and would become increasingly possible and spatially extensive with warming. This tendency is also supported by the conventional multi-model (CMIP6) projection, especially evident in larger ensembles. Lower reaches of the valley and parts of Southwest China have greater chances of repeated exposure to the 2022-like heat—drought—fire—flood quadruple compound events. In the presence of favorable internal variability in line with future warming, it is plausible to see more than half of the valley at simultaneous risk of the 2022-like quadruple compound event. Our possibility projection highlights the urgency of accelerating the existing univariate extremes—oriented adaptation measures to better address emerging threats from unfamiliar compound hazards.