Florida and the Surging Sea: A Vulnerability Assessment with Projections for Sea Level Rise and Coastal Flood Risk
Sea levels are rising at an accelerating rate, and the scientific community is confident that global warming is the most important cause. Higher sea levels translate to more and higher coastal floods. Using local sea level projections based on global scenarios from the U.S. Army Corps of Engineers, and also used by the four-county Southeast Florida Regional Climate Change Compact, this analysis finds that floods rising 3 ft above the high tide line at Key West are near certain this century under any sea level rise scenario. Six-foot floods range from very unlikely under slow rise, to 80% likely under fast rise. Key West has statistically the lowest flood levels of all eight water level stations analyzed in this study, from Pensacola to Tampa to Fernandina Beach, and thus makes a convenient least common denominator.
2120 square miles of land lie less than 3 feet above the high tide line in Florida. Some $156 billion in property value, and 300,000 homes, sit on that land. These figures jump to $580 billion and 1.4 million homes on 4660 square miles of land under 6 feet. Every inch of sea level rise within these ranges will be more damaging than the previous inch. This escalating risk, considered together with recent acceleration in sea level rise and projections for that trend to continue, places Florida in double jeopardy. Damage from sea level rise and coastal flooding is likely to turn sharply upward during the course of this century.
$76 billion of Florida property sits on land less than two feet above the high tide line. Within less than the term of a 30-year mortgage, sea level rise could cause floods this high to occur once every five years, or even every year, depending on location within the state.
Florida has 2,555 miles of road below 3 feet, 35 public schools, one power plant, and 966 EPA-listed sites such as hazardous waste dumps and sewage plants. At 6 feet, these numbers grow to more than 16,000 miles of road, 298 schools, 13 power plants, and 5,474 EPA-listed sites.