Substantial increases in compound climate extremes and associated socio-economic exposure across China under future climate change

Under climate change, China faces intensifying compound extreme events with serious socio-economic ramifications, yet their future variations remain poorly understood. Here, we estimate historical hotspots and future changes of two typical compound events, i.e., sequential heatwave and precipitation (SHP) and concurrent drought and heatwave (CDH) across China, leveraging a bivariate bias correction method to adjust projections from global climate models. Results show substantial future increases in frequency, duration, and magnitude for both events, with the durations projected to double nationwide. The increases are more evident under higher emission scenarios, and could be largely underestimated if neglecting variable dependence during bias correction process. The projected changes will escalate socio-economic exposure across China's major urban clusters, among which Guangdong-Hong Kong-Macao will face the highest risk. Our findings underscore the necessity of carbon emission controls, and call for adaptive measures to mitigate the threats induced by rising compound hazards in a changing climate.