Increased US coastal hurricane risk under climate change

Several pathways for how climate change may influence the U.S. coastal hurricane risk have been proposed, but the physical mechanisms and possible connections between various pathways remain unclear. Here, future pro-jections of hurricane activity (1980-2100), downscaled from multiple climate models using a synthetic hurricane model, show an enhanced hurricane frequency for the Gulf and lower East coast regions. The increase in coastal hurricane frequency is driven primarily by changes in steering flow, which can be attributed to the development of an upper-level cyclonic circulation over the western Atlantic. The latter is part of the baroclinic stationary Rossby waves forced mainly by increased diabatic heating in the eastern tropical Pacific, a robust signal across the multimodel ensemble. Last, these heating changes also play a key role in decreasing wind shear near the U.S. coast, further aggravating coastal hurricane risk enhanced by the physically connected steering flow changes.

Automated summary

Several pathways have been proposed to explain how climate change may affect the U.S. coastal hurricane risk, but the physical mechanisms and possible connections between these pathways are still unclear. Future projections of hurricane activity (1980-2100), based on multiple climate models using a synthetic hurricane model, show an increased frequency of hurricanes in the Gulf and lower East coast regions. This increase in coastal hurricane frequency is mainly driven by changes in steering flow, which can be attributed to the development of an upper-level cyclonic circulation over the western Atlantic.