At a Glance

By 2012, the rate of ice loss had accelerated to nearly four times what it was in 2003.The lead author says humanity may have reached the point of no return.

Greenland's ice sheet is melting far faster than previously thought and may have reached the point of no return, a team of researchers say.

Most recent research on Greenland's melting has focused on the island’s southeast and northwest regions, where outlying glaciers calve large icebergs into the Atlantic Ocean.

But a team of scientists led by Michael Bevis, lead author and professor of geodynamics at The Ohio State University, decided to look at Greenland’s less-studied southwest region and found that this region that is devoid of large glaciers has had the largest sustained ice loss from early 2003 to mid-2013.

“Whatever this was, it couldn’t be , because there aren’t many there,” said Bevis in a press release. “It had to be the surface mass — the ice was melting inland from the coastline.”

For the study published Monday in the Proceedings of the National Academy of Sciences, the team found the had accelerated to nearly four times what it was in 2003 by 2012, much of that coming not from glaciers calving into the sea but from large rivers of meltwater from the ice sheet itself.

“We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers,” Bevis said. “But now we recognize a second serious problem — increasingly large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea.”

Bevis says that humanity may be hitting a melting "tipping point" from which the planet may never recover.

“The only thing we can do is adapt and mitigate further global warming — it’s too late for there to be no effect,” he said. “This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point.”

Satellite data indicates that between 2002 and 2016, Greenland lost approximately 280 gigatons of ice per year, equivalent to 0.03 inches of sea level rise each year, according to the press release.

A separate study published last month in the journal Nature found that Greenland’s ice sheets are than pre-industrial levels and 33 percent above 20th-century levels.

The accelerated melting could have dire consequences for the planet's low lying islands and coastal cities. in the world are near coasts, while 40 to 50 percent of the world's population live in coastal regions, according to the United Nations Atlas of the Oceans.

(MORE: Even Belize's Great Blue Hole, the World's Largest Sinkhole, Isn't Safe From Plastic Pollution)

Human-caused global warming, along with the North Atlantic Oscillation, a natural weather phenomenon that brings warmer air to West Greenland, clearer skies and more solar radiation is the cause for the rapid acceleration on the ice sheet that contains enough water to .

“These oscillations have been happening forever,” Bevis said. “So why only now are they causing this massive melt? It’s because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained, global warming.”

Bevin and his team say scientists need to be watching Greenland’s snowpack and ice fields more closely, especially in and near southwest Greenland.

“We’re going to see faster and faster sea level rise for the foreseeable future,” Bevis said. “Once you hit that tipping point, the only question is: how severe does it get?”