The sea level on a stretch of the US Atlantic coast that features the cities of New York, Norfolk and Boston is rising up to four times faster than the global average, a report said Sunday.
This increases the flood risk for one of the world's most densely-populated coastal areas and threatens wetland habitats, said a study reported in the journal Nature Climate Change.
Since about 1990, the sea level along the 1,000-kilometre (620-mile) "hotspot" zone has risen by two to 3.7 millimetres (0.08 to 0.15 inches) per year.
The global rise over the same period was between 0.6 and one millimetre per year, said the study by the US Geological Survey (USGS).
If global temperatures continue to rise, the sea level on this portion of the coast by 2100 could rise up to 30 centimetres over and above the one-metre global surge projected by scientists, it added.
The localised acceleration is thought to be caused by a disruption of Atlantic current circulation.