Projecting spatial synchrony and socioeconomic risk of heatwaves and extreme precipitation in the future

Increasing heatwaves (HWs) and extreme precipitation events (EPEs) pose threats to human society and contribute to climate inequality under global warming. However, the spatial synchrony between HWs and EPEs and its evolution under future climate scenarios remain inadequately quantified, limiting current knowledge to their risk variations in the future. To bridge this gap, we develop a framework incorporating the N-dimensional Multivariate Quantile Mapping bias correction (MBCn) approach to reduce biases in climate projections, the complex network analysis, and the Deprivation-Risk assessment and quantify the spatial synchrony to evaluate associated climate risk inequality. Our results demonstrate that the proportion of land area affected by HWs and EPES strengthen substantially under SSP5-8.5 (65.1%; 7.8%), compared to SSP1-2.6 (21.4%; 6.6%) compared to historical baseline (8.8%; 5.6%). Global warming reshapes the teleconnection patterns of HWs, contributing to rising synchrony of HWs and EPEs. Under SSP5-8.5, network synchrony increases by 558%, 368%, and 11% for HW-HW, HW-EPE, and EPE-EPE, respectively, relative to the historical baseline. We also find that network hubs evolve from regional hotspots to transcontinental clusters. Additionally, we report that groups of different deprivation levels face unequal socioeconomic risks in the future: under SSP3-7.0, high-risk zones are concentrated in impoverished regions, whereas under SSP5-8.5, exposure increasingly affects affluent populations, with Low Deprivation-High Risk groups rising to 39.5%, particularly in southeastern China and along the U.S. coasts. These findings challenge the traditional vulnerability boundaries, and highlight that under continued warming, even low-deprivation regions are not insulated from the emerging risks.