CMIP6‐Driven CaMa‐Flood Simulations Reveal Anthropogenic Control on Global Flood Extremes via Precipitation and Snowmelt Drivers

Abstract

Human activities accelerate global climate change through greenhouse gas emissions, which has profoundly influenced global floods. Nevertheless, the impacts of anthropogenic climate change on flood variations remain unclear. Here, we drive the CaMa‐Flood model with CMIP6 runoff to simulate global historical flood during 1951–2014. Our results reveal a significant increase in floodplain water depth across 49% of global river basins, which is associated with increased extreme precipitation and snowmelt. Furthermore, the contribution of anthropogenic climate change to flood trends and extreme floods frequency have been quantified by comparing simulations forced by natural forcings (NAT) against those driven by natural and anthropogenic forcings (ALL). We find that anthropogenic climate change is the dominant driver of long‐term flood changes. It has increased the frequency of 100‐year extreme floods across approximately two‐thirds of the basins by around 22.6%. This study implies the urgent need for targeted flood mitigation and adaptation strategies under climate change.