New Maps Show Sea Level Rise Submerging America's Coastal Cities

"Sea level rise gives climate change an address." That's Climate Central's Ben Strauss talking about the importance of sea level rise in better communicating the threat of climate change to the public.

Strauss worked with University of Arizona scientists Jeremy Weiss and Jonathan Overpeck, to create a map of sea level rise's potential effects on low-lying, developed coastal areas. (The paper, "Implications of Recent Sea Level Rise Science for Low-Elevation Areas in Coastal Cities of the Conterminous U.S.A.," will be published this week in Climatic Change Letters.) Their findings: Rising sea levels will likely inundate 9 percent of the land within 180 American cities by the end of the century.

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Writes Strauss, "We believe these are the first estimates of vulnerability to sea level rise covering each and every major coastal city in the Lower 48—the places where Americans live in our highest concentrations."

Though cities along the Gulf of Mexico and the South Atlantic coast are most vulnerable, Strauss notes "we also uncovered less familiar pockets of risk, from Virginia Beach to the New Jersey Shore, from Tampa Bay to the San Francisco Bay Area."

It should be noted that the 9 percent figure above is based on the estimate of a one meter rise by 2100, which is on the low end of the best estimates current science has to offer. An incredible 36 percent of the land area of America's coastal cities lies under six meters of elevation, and if we continue on a business-as-usual greenhouse gas emissions track, six meters of sea level rise is all but inevitable in the longer term. Maybe not in your lifetime or mine, but certainly something our grandchildren would face.

Strauss and his colleagues also didn't account for the fact that high tide levels vary by region. They're tackling that next.

In a separate but related study, NASA just released a visualization of how sea level rise would impact the Bay Area. Visualizations like this and another, similar project in New York City are going to become more and more important as urban planners and city governments slowly come around to recognizing the very serious threat that rising sea levels will pose on our urban areas. It will be very interesting to see how mayors and governors who are skeptical of climate science deal—or refuse to deal—with these predictions and projections in decades ahead.

Climate Central also has a disconcerting slide show featuring the 20 big American cities that should be most concerned about rising seas.