U.S. coastal population and energy facilities located below 4 feet. Climate Central

By Benjamin H. Strauss
20 April 2012 Good morning, Senator Bingaman and colleagues. Thank you for your attention to this important topic. I am Dr. Ben Strauss, coauthor of two recent peer-reviewed papers making an assessment of sea level risk to the lower 48 states, as well as the summary report submitted with my written testimony. I am also Director of the Program on Sea Level Rise at Climate Central, a nonprofit research organization that conveys scientific information to the public. We take no policy positions. In my testimony today, as in my research, I will address two topics: first, how sea level rise is amplifying the risk from coastal storm surges, and then, what communities and assets are exposed at the lowest elevations. The nearest-term sea level projections I will share, in inches, may sound small. But they are dangerous. The key problem is that rising seas raise the launch pad for coastal storm surges, and tilt the odds toward disaster. Just a few extra inches could mean the difference to flood a family’s basement — or New York City’s subway system, disabling it for months. You might think of it this way: raising the floor of a basketball court would mean a lot more dunks. In the long term, we are likely to see many feet of sea level rise, and be forced to redraw the map of the United States. The high end of projections for this century would be enough to turn Miami-Dade County, Florida, into a collection of islands. But in the near term, we will mainly experience sea level rise as more and more coastal floods, reaching higher and higher. In fact, according to our analysis, sea level rise due to global warming has already doubled the annual risk of extreme coastal flooding across widespread areas of the nation. Global average sea level has risen about 8 inches since 1880. This means that warming is already contributing to the damage caused by any coastal flood today. Diverse studies bracket additional global rise likely this century between 1 and 7 feet. In some areas, especially for Louisiana, Texas, and mid-Atlantic states, sinking land will add to the total effective rise and compound problems. Taking such local factors into account, we made mid-range projections for sites around the lower 48 of 1-to-8 total inches increase by 2030, and 4-to-19 inches by 2050, depending upon location. All along the Pacific, from Seattle to the Oregon coast to San Francisco to Los Angeles, the component of past and projected sea level rise from global warming more than triples the odds of “century” floods by 2030 in our analysis, as you can see from the display. The same is true inside the Chesapeake and Delaware Bays, and many sites to the north. […]

Senate Testimony on Sea Level Rise by Ben Strauss