Observed Increase in the Spatial Extent of Extreme Precipitation Events Attributed to Anthropogenic Climate Change

Abstract Extreme precipitation events (EPEs) pose severe impacts on human health and the economy, with spatially widespread events typically resulting in greater losses than localized ones. Unraveling the spatial extent of these events is key to anticipating and mitigating their risks, but global insights remain notably lacking. Here, we assess the spatial extent of EPEs across global land areas from 1982 to 2019, combining robust observational analyses with climate model simulations to identify both trends and external forcings. Our results reveal a pronounced global increase in the spatial extent, with evident expansion trends observed in South America, Oceania, Europe, and Asia. Attribution analyses demonstrate that anthropogenic climate change dominates these upward trends, where the enhancing effects of greenhouse gas emissions outweigh the dampening effects of aerosols. Our findings highlight the critical role of human activities in reshaping the spatial footprint of EPEs, providing new insights into changes in EPEs and their associated risks in a warming climate.