University of Delaware
delware environmental institute

EarthSky: Flooding tipping points earlier than expected for U.S. coasts

By 2050, a majority of U.S. coastal areas – including dozens of cities – are likely to be threatened by 30 or more days of flooding each year due to dramatically accelerating impacts from sea level rise. That’s according to a study published December 18 in Earth’s Future, a journal of the American Geophysical Union.

The new study establishes a benchmark for what the authors call “tipping points” for when so-called nuisance flooding — flooding between 0.3 to 0.6 meters (one to two feet) above local high tide — occurs 30 or more times a year.

The study suggests that that these tipping points will be met or exceeded by 2050 at most of the U.S. coastal areas studied, regardless of sea level rise likely to occur this century. According to the study authors, these regional tipping points will be surpassed in the coming decades in areas with more frequent storms, or areas where local sea levels rise more than the standard global projection of 0.5 to 1.2 meters (1.5 to four feet). This also includes coastal areas like Louisiana where subsidence is causing land to sink below sea level.