Why US could see deep sea rise over next 30 years

America's coastline will see sea levels rise in the next 30 years by as much as they did in the entire 20th century, with major Eastern cities hit regularly with costly floods even on sunny days. By 2050, seas lapping against the U.S. shore will be 10 to 12 inches higher, with parts of Louisiana and Texas projected to see waters a foot and a half higher, according to a report issued by the National Oceanic and Atmospheric Administration and six other federal agencies. Experts warned the cost will be high, pointing out that much of the American economy and 40% of the populations are along the coast.

However, the worst of the long-term sea level rise from the melting of ice sheets in Antarctica and Greenland probably won't kick in until after 2100, said ocean service oceanographer William Sweet. Sea level rises more in some places than others because of sinking land, currents and water from ice melt. And the greatest rise in the U.S. will be on the Gulf and East Coasts, while the West Coast and Hawaii will be hit less than average, experts said. While higher seas cause much more damage when storms such as hurricanes hit the coast, they are becoming a problem even on sunny days.