From the article:

A large area of the Greenland ice sheet once considered stable is actually shedding massive amounts of ice, suggesting that future sea-level rise may be worse than expected, a team of scientists warned yesterday in a new study.

The research in Nature Climate Change signals that many climate models may be too conservative in their projections through this century, as they are not considering ice loss from the northeast portion of Greenland. The discovered ice loss in the northeast -- which has been largely overlooked to date -- is worrisome because the drainage basin there covers 16 percent of the ice sheet and holds the capability of funneling ice deep from Greenland's interior out to sea, the scientists said.

"This is an area we should be worried about because it's huge. Who knows, maybe this is starting something very big," said Shfaqat Khan, senior researcher at Technical University of Denmark, and the lead author of the study. The ice loss found in northeast Greenland is accelerating, and it is uncertain how many years it will continue, he said.