The Impact of Projected Changes in Hurricane Frequencies on U.S. Hurricane Wind and Surge Damage

Abstract We use a simple risk model for U.S. hurricane wind and surge economic damage to investigate the impact of projected changes in the frequencies of hurricanes of different intensities due to climate change. For average annual damage we find that changes in the frequency of category 4 storms dominate. For distributions of annual damage we find that changes in the frequency of category 4 storms again dominate for all except the shortest return periods. Sensitivity tests show that accounting for landfall, uncertainties and correlations leads to increases in damage estimates. When we propagate the distributions of uncertain frequency changes to give a best estimate of the changes in damage, the changes are moderate. When we pick individual scenarios from within the distributions of frequency changes, we find a significant probability of much larger changes in damage. The inputs on which our study depends are highly uncertain, and our methods are approximate, leading to high levels of uncertainty in our results. Also, the damage changes we consider are only part of the total possible change in hurricane damage due to climate change. Total damage change estimates would also need to include changes due to other factors, including possible changes in genesis, tracks, size, forward-speed, sea-level rise, rainfall and exposure. Nevertheless, we believe that our results give important new insights into U.S. hurricane risk under climate change.