As Hurricane Sandy vividly demonstrated in late October, coastal communities across the U.S. are increasingly vulnerable to flooding and storm surge as sea levels rise. Storm surge from more extreme storms on top of higher sea levels increases coastal flooding by allowing floodwaters to move further inland, putting people, homes, and businesses in harm’s way.
Given Maryland’s thousands of miles of shoreline, coastal hazards are an ever-present threat. The state’s coastal zone includes the 16 counties that border the Atlantic Ocean, Chesapeake Bay, and Potomac River—an area encompassing two-thirds of the state’s total land, which contains nearly 70 percent of all residents. Since the early 1900s, relative sea levels along Maryland’s coast have risen over one foot, placing 13 islands in Chesapeake Bay underwater. And approximately 580 acres of coastal land are lost to erosion every year.
- Abandoned home on Holland Island in 2009, which has since collapsed into the sea (photo credit: flickr user baldeaglebluff)
Rising seas due to warmer, expanding oceans and melting ice will only exacerbate existing coastal hazards, further jeopardizing communities in coastal areas. Relative sea levels are projected to rise by approximately one foot by mid-century and about three feet by the end of the century—though these projections were developed in 2008 and more recent data on rates of future sea level rise are now available. In fact, a 2012 study by the U.S. Geological Survey found that rates of sea level rise along the mid-Atlantic coast (from Cape Hatteras to Boston) are three to four times greater than the global average primarily due to the weakening of ocean currents. Warmer water temperatures and melting glaciers are decreasing the density of water in the northern Atlantic, which is subsequently affecting ocean circulation patterns.
According to our recent report, Maryland has been among the leading states in the country when it comes to preparing for climate change impacts. And the state is not idly standing by. Last week Governor Martin O’Malley signed the Climate Change and Coast Smart Construction Executive Order, which will help to reduce flooding risks to state buildings and public infrastructure in coastal areas. The order directs:
- State agencies to consider coastal flooding and sea level rise risks in the siting, design, and construction of new state buildings and the reconstruction of substantially damaged state buildings;
- The Department of General Services to update its engineering and design guidelines to require state agencies to elevate new and rebuilt state structures two or more feet above the 100-year flood level;
- The Department of Natural Resources to develop recommendations for siting and design requirements for coastal state infrastructure such as roads, bridges, and water systems and non-state infrastructure that receive public funds;
- The Scientific and Technical Working Group of the state’s climate change commission to update statewide sea level rise projections based on the latest climate science.
These are critical first steps that every coastal state should be taking to prepare communities for more extreme storms and higher seas. By not factoring climate change into fundamental land use and structural design decisions, states are turning a blind eye to a problem that will only get worse. It’s time for other governors across the country to stop ignoring the problem and, like Governor O’Malley, start implementing solutions.