Last updated December 4, 2018

Storm Surge Increase

Global warming has boosted storm surge—the temporary increase in sea level at a particular location due to weather conditions like low atmospheric pressure and strong winds. Hurricane storm surge now rides higher on seas that have risen over the last century, much of which is attributable to melting ice sheets and a warmer, expanding ocean.

The height of flooding attained during a hurricane is the product of storm-surge height, timing in the astronomical tidal cycle and sea level rise. Increases in storm surge related to climate change can be due to both rising seas and increasing storm wind speeds. Storm surge is the most important impact of tropical cyclones in coastal regions.

Climate change has already contributed about 8 inches (0.19 meters) to global sea level rise, and this has dramatically amplified the impact of cyclones and other storms by increasing baseline elevations for waves and storm surge. A small vertical increase in sea level can translate into a very large increase in horizontal reach by storm surge depending upon local topography. For example, sea level rise extended the reach of Hurricane Sandy by 27 square miles, affecting 83,000 additional individuals living in New Jersey and New York City and adding over $2 billion in storm damage. Aided by sea level rise, Hurricane Matthew set several storm tide records during its approach to the eastern sea board.