Researchers from Princeton University and the Massachusetts Institute of Technology said regions such as the New York City metropolitan area that have experienced a disastrous flood roughly every century could instead become submerged every one or two decades, a Princeton University release reported.
Writing in the journal Nature Climate Change, they said projected increases in sea level and storm intensity brought on by climate change would make devastating storm surges -- the destructive mass of water pushed inland by large storms -- more frequent.
Citing New York City as an example, researchers said stronger storms and a 3-foot rise in sea level due to climate change would turn so-called "100-year floods" with depths 5.7 feet above tide level into events that could occur every 25 years.
"Coastal managers in cities like New York make daily decisions about costly infrastructure that would be affected by such storms," Princeton geoscience professor Michael Oppenheimer said. "They need a reliable indicator of the risk."
Knowing the frequency of storm surges may help planners design seawalls and other protective structures, researchers said.
"When you design your buildings or dams or structures on the coast, you have to know how high your seawall has to be," lead study author Ning Lin at MIT said, noting Manhattan's seawalls now stand a mere five feet high.
"You have to decide whether to build a seawall to prevent being flooded every 20 years."