Climate change impacts to the coastal flood hazard in the northeastern United States

It is widely accepted that climate change will cause sea level rise and increase the coastal flood hazard in many places. However, climate change also has significant implications for hurricane climatology. While the effect of climate change on hurricane frequency is inconclusive, there is a general consensus among climate scientists that hurricane intensity will increase over the coming decades. A number of studies indicate that hurricane size and translation speed may intensify with climate change as well. Each of these properties influences storm surge generation and propagation, and thus has significant implications for the coastal flood hazard, particularly in the densely populated northeast region of the U.S. As coastal populations grow, increasing the resilience of the built environment will become an increasingly necessary priority. Local, detailed, and comprehensive flood hazard assessment is a central aspect of such efforts. In this work, we integrate global climate data, statistical-deterministic hurricane modeling, physics-based numerical storm surge modeling, and extreme value analysis methods to comprehensively assess the present day and end of century flood hazard due to hurricanes for several coastal communities along the U.S. North Atlantic coastline. We find that by the end of the century, annual exceedance probabilities of the 100-year flood may increase by factors as great as 7 due to sea level rise, and on average projected changes to tropical cyclone climatology cause these probabilities to double. For truly effective long-term resilience efforts, coastal engineers, planners, and other stakeholders must account for climate change impacts to both sea level and tropical storm climatology.