National Geographic News
By 2100 visitors to Boston could be parking their boats, not their cars, in Harvard Yard.
Major cities in the northeastern U.S. and eastern Canada "are directly in the path of the greatest rise" in sea level if Greenland continues to melt due to global warming, a new study says.
Scientists believe that the influx of fresh water from the disintegrating ice sheets will disrupt a circulation pattern in the Atlantic Ocean, causing seas to expand.
The new projections call for an extra 4 to 12 inches (10.2 to 30.5 centimeters) on top of the rise of 8 inches (20.3 centimeters) previously estimated in the journal Nature Geoscience in March.
That previous study found that, if global warming continues, sea levels around New York City would rise by twice as much as in other parts of the United States within this century.
In the new study, researchers considered three scenarios: that Greenland's present melt rate of 7 percent would continue, or a drop to either one or 3 percent a year—viewed by many as more likely, as the rate is actually expected to slow in coming decades.
"We hope the high end wouldn't happen," said study lead author Aixue Hu of the National Center for Atmospheric Research in Boulder, Colorado.
But "we should be aware that there's a potential the melt of the Greenland ice sheet could be faster than we expected."
Of the three scenarios, the two lower melt rates are more realistic, according to computer models of future ice sheet melting, Hu said.
A 3 percent melt rate would mean an extra 12 inches (30.5 centimeters) on top of the predicted global sea level rise of 21 inches (54 centimeters), and a one percent rate would mean an extra 8 inches (20.3 centimeters) for the region.
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