Sea Level Rise Poses Big Threat to Washington, D.C.

(Originally published on Washington Post's Capital Weather Gang)

Global warming-related sea level rise constitutes a major threat to the nation’s capital, with the potential to inundate national monuments, museums, military bases, and parts of the Metro Rail system during the next several decades and beyond, according to a recent study published in the journal “Risk Analysis.” The study helps localize a problem that is more typically discussed at the global level, and makes clear that public officials in Washington, D.C. must make decisions in the near-term in order to minimize future losses.

Inundation resulting from 0.1 meter (m), 0.4 m, 1.0 m, 2.5 m, and 5.0 m of sea level rise in Washington, D.C. (left maps); and a composite on right map. Credit: Risk Analysis

Considering the city’s history, it should come as no surprise to learn that Washington is vulnerable to sea level rise. The National Mall and Foggy Bottom were originally marshland, and the area between the Anacostia River and I-295 used to be open water. What is rather disturbing and less well known, though, is just how vulnerable D.C. is to even minor amounts of sea level rise, which according to some studies is virtually guaranteed as the amounts of greenhouse gases in the atmosphere continue to climb, temperatures rise, and mountain glaciers and ice caps melt.

The study, led by Bilal Ayyub of the University of Maryland, found that even if sea level rise turns out to be at the very low end of projections, it would still cause significant damage in Washington. For example, if the local sea level were to rise by just 0.1 meter, or about 4 inches, by 2043, nearly 68,000 people would be affected, and property damage would total upwards of $2 billion — without including damage to military bases and government property.

The study points out the vulnerability of the military installations that line the Potomac River, particularly Bolling Air Force Base, which would lose 23 buildings to inundation by 2043 if sea level rise proceeds at its recent rate, and many more if it speeds up.

(Read the rest of the story, including two more telling images of D.C.'s vulnerability to sea level rise, at the Capital Weather Gang blog)