What drives the compound drought and heat events? A dynamic perspective

Compound drought and heat events (CDHE) have garnered significant attention due to their amplified negative impacts on socio-economic systems and ecosystems. However, the mechanisms driving their occurrence and evolution remain unclear, particularly from a dynamic, long-term perspective. This study develops a novel dynamic framework that integrates Meta-Gaussian models, differential equations, and random forest regression to systematically characterize CDHE, attribute key drivers, and identify regional disparities. Results indicate a significant increase in the frequency and intensity of CDHE globally from 1960 to 2022. Attribution analysis reveals that heat is the dominant driver of CDHE, followed by drought conditions and their interaction. Notably, our findings reveal a dynamic shift in CDHE drivers under climate warming: the influence of heat declines, while drought conditions and their interaction gradually become the primary factors. Furthermore, a distinct shift in the driving mechanisms from arid to humid regions is identified. In arid areas, CDHE is more sensitive to changes in drought conditions, whereas in humid regions, heat plays a predominant role. This study advances the understanding of CDHE dynamics by elucidating their regional driving mechanisms and climatic influences. These findings provide critical insights to enhance predictive models and inform adaptive management strategies.