Enhanced global storm surges by tropical cyclone poleward migration

Tropical cyclone-induced storm surges pose significant and growing threats to coastal regions; however, their long-term evolution in response to changing tropical cyclone characteristics remains poorly quantified. Here, by conducting a comprehensive global analysis, we find that tropical cyclone-induced storm surge has increased globally by 20% over the period 1982-2024, which is also statistically significant in both hemispheres. Notably, such increases are 28% over the western North Pacific, 38.2% over the eastern Pacific and 31% over the South Pacific, respectively. Through statistical decomposition, we identify the poleward migration of tropical cyclone activity as a key factor amplifying the storm surge in both hemispheres. Furthermore, the intensification of major tropical cyclones and increasing sizes of weak tropical cyclones also play important roles in enhancing storm surges across multiple basins. These changes in tropical cyclone activity, particularly the poleward migration, are largely related to human-induced global warming, underscoring the intrinsic link between tropical cyclone characteristics and associated surge risk under a changing climate. Our findings highlight the necessity of explicitly incorporating the evolving tropical cyclone activity into climate projections and provide a critical framework for assessing compound coastal flood risks in a warming world.