Accounting for tropical cyclones more than doubles the global population exposed to low-probability coastal flooding

Abstract Storm surges that occur along low-lying, densely populated coastlines can leave devastating societal, economical, and ecological impacts. To protect coastal communities from flooding, return periods of storm tides, defined as the combination surge tide, must be accurately evaluated. Here we present tide using a novel integration two modelling techniques. For induced by extratropical cyclones, use 38-year time series based on ERA5 climate reanalysis. tropical synthetic cyclones STORM dataset representing 10,000 years under current conditions. Tropical cyclone levels are probabilistically combined with tidal levels, computed empirically. We estimate 78 million people exposed to 1 in 1000-year flood caused which more than doubles 192 M when taking into account. Our results show previous studies have underestimated global exposure low-probability flooding 31%.