Anthropogenic exacerbation of global high-risk compound hot–dry events over the past century

As climate warms, the compound hot–dry events (CHDEs) have become more frequent across most regions of the globe, bringing serious threats to both the human population and the natural environment in affected areas. In the study, a copula-based probability index (PI) is used to explore variations in risk indicators associated with global and regional CHDEs by considering both the annual PI mean and variability. Across most of the world, the risk associated with CHDEs has increased significantly over the past century during 1901–2020, with approximately 89% of land grid cells experiencing increasing trends in high-risk CHDEs. In contrast, the low-risk CHDEs has declined evidently. Detection and attribution analysis indicates that anthropogenic greenhouse gas dominates the high-risk CHDEs and follows similar trends to the observed increase at subregional to continental scales, especially in North America, Europe, Asia, and Oceania. These results emphasize the importance of reducing anthropogenic greenhouse gas emissions to restrict the expansion of high-risk CHDE areas in the globe.