Sea levels are rising in the Florida Keys and that will continue and most likely accelerate in the coming decades, scientists say. Expensive mitigation measures will have to be implemented to stave off flooding but complete submersion of the island change is not a definite conclusion, though that depends greatly on worldwide cooperation to move away from fossil fuels. The Monroe County Commission met recently to hear from scientists and engineers on what to expect in terms of where and when rising seas will threaten roads and properties and where the plans to raise vulnerable roadways stand. Dr. William Sweet, an oceanographer with NOAAâs National Ocean Service Center who worked with the U.S. Department of Defense to develop the latest sea-level rise scenarios, gave a lengthy presentation to the commission, outlining data that showed sea level increases in the Keys are about on par with the national average. He said water levels are rising about 3 millimeters per year, amounting to about an inch every eight years.