A new study, which has been published in Proceedings of the National Academy of Sciences, reveals that U.S. cities such as New Orleans and Miami will sink below rising seas regardless of efforts to curb global warming.
Lead author Ben Strauss, vice president for sea level and climate impacts at Climate Central, said scientists have already established that if we do nothing to decrease burning of fossil fuel up to the year 2100, the planet will face sea level rise of 14-32 feet.
The authors projected business-as-usual carbon emissions, in addition to the complication of the melting West Antarctic ice sheet, a process some experts fear is irreversible.
Strauss said that an online tool at http://choices.climatecentral.org allows users to see the impacts on various U.S. cities and a global version is expected in the next month.
The tool demonstrates which US cities might face lock-in dates beyond which the cumulative effects of carbon emissions likely commit them to long-term sea-level rise that could submerge land under more than half of the city's population.
Norfolk, Virginia, faces a lock-in date of 2045 under a scenario of unabated carbon emissions. For cities such as New Orleans and Miami, the limits are already exceeded. Miami's porous limestone foundation and low elevation mean that sea walls and levees will not help, Strauss said.
Florida has the most number of big cities at risk from sea level rise, holding 40 percent or more of the U.S. population living on potentially affected land. After Florida, the next 3 most affected states are New York, California and Louisiana.
According to the study, New York City is also in danger, and under a worst-case scenario, the city could be consigned to an un-liveable future by the year 2085.
A total of fourteen cities with more than 100,000 residents could avoid locking in this century, including Virginia Beach in Virginia, Jacksonville, Florida, Chesapeake, Norfolk, and Stockton and Sacramento in California.