Greenland's Vast Ice Sheet Is Way Less Stable Than We Thought, And That's Bad News For The World


Greenland's Vast Ice Sheet Is Way Less Stable Than We Thought, And That's Bad News For The World
An iceberg detached from the Jakobshavn glacier in western Greenland. New research suggests the island's enormous ice sheet is more unstable than scientists previously believed.
Greenland should melt, it would be catastrophic because sea levels would rise more than 20 feet. This would submerge coastal cities worldwide and threaten land that’s home to at least 15 million Americans.

Scientists had believed that the world’s second largest ice body had been relatively stable during the recent geological past. Even during periods of warming, the massive mantle of ice had remained largely intact, they thought.

But new research suggests that this assumption may be grossly off the mark.

Greenland's Vast Ice Sheet Is Way Less Stable Than We Thought, And That's Bad News For The World
A researcher observes a canyon created over time by a meltwater stream on the Greenland's ice sheet, July 16, 2013.

The Northern European country’s ice sheet appears to have melted nearly completely at least once in the not-too-distant geological past, according to a groundbreaking study published on Thursday in the journal Nature.

By studying a sample of bedrock taken from beneath Greenland’s ice deposit, researchers found that the autonomous Danish territory was ice-free (or “deglaciated”) for “extended periods during the Pleistocene epoch,” stretching from 2.6 million years to 11,700 years ago. Researchers estimate that the ice sheet shrunk to less than 10 percent of its current size and stayed that way for at least 280,000 years.

Greenland’s mighty ice sheet, it seems, may not be as impregnable as previously believed.

“Unfortunately, this makes the Greenland ice sheet look highly unstable,” said study co-author Joerg Schaefer, a paleoclimatologist at Columbia University’s Lamont-Doherty Earth Observatory, in a news release.

Greenland's Vast Ice Sheet Is Way Less Stable Than We Thought, And That's Bad News For The World
Icebergs that have broken off the Sermeq Kujalleq ice sheet, Qaasuitsup, Greenland.

Interestingly, another study published this week in the same edition of Nature revealed a significantly different picture of the ice sheet’s past. Also a result of bedrock testing but from a sample taken from a different location, the paper concluded that Greenland had maintained at least some ice cover for the past 7.5 million years.

Scientists say, however, that the two studies aren’t necessarily contradictory - and may in fact inform the other. Nearly all of Greenland’s ice could’ve melted at certain times in the past, but some ice might’ve remained in areas of higher elevation.

“Both studies show that there’s the potential for the ice sheet to be quite dynamic and change over time,” University of Vermont professor Paul Bierman, lead author of the second study, told Time magazine.

Greenland's Vast Ice Sheet Is Way Less Stable Than We Thought, And That's Bad News For The World
Water is seen on part of Greenland's glacial ice sheet, July 2013.

Authors of both papers agree that more research needs to be done to better understand the ice sheet’s history. And global warming should be taken as a real and present threat to the future of the ice body - and the planet as a whole.

“We do what we’re doing with the atmosphere right now at our own risk,” Bierman told Time. “We’re dealing with an incredibly complex system on Earth and we don’t know the half of it. There are surprises lurking out there.”

Schaefer had a more direct warning. “We have to be prepared that this ice sheet might go again, and it might go again soon,” he said, according to MIT Technology Review.

“Soon,” of course, is relative to geological time. It could take centuries or even millennia for all that ice to melt.

But there’s still plenty of reason to be concerned. Greenland currently contributes about a quarter of the three millimeters that global sea levels rise every year - and climate change could greatly accelerate the speed of the ice sheet’s melting. “Projections of sea-level rise during this century hover around 3 or 4 feet, but many, including the one from the Intergovernmental Panel on Climate Change, do not take Greenland into account,” states a blog post on Columbia’s website.

The impacts of climate change on Greenland are already being seen.

The island’s ice mantle is melting five times faster than it was in the 1990s, according to a 2012 study.

A Google Earth timelapse of northeast Greenland between 1984 and 2016 shows just how dramatic the melt has been on some parts of the country (use the scrollbar to move backwards and forwards in time):


Related...
Watch How Climate Change Is Rapidly Transforming Our Planet What You Can Do Right Now To Stop Trump's Dangerous Climate Agenda This Is VERY Bad For The Fight Against Climate Change Greenland's Ice Sheet Is Filthy, And That's A Problem Watch Greenland Melt Away Rising Sea Levels Swallow 5 Pacific Islands



Add Comment

all comments

  Other news

more
Wiretap Allegations: From Trump Tweets to Capitol Hill

Wiretap Allegations: From Trump Tweets to Capitol Hill..

23-Mar, 22:30

House Intelligence Committee Chairman Rep. Devin Nunes, R-Calif., and the...

South Africa police warn of taxi rape gang in Johannesburg

South Africa police warn of taxi rape gang in Johannesburg..

23-Mar, 08:46

A boy of 10 was forced to lie face down while his mother was subjected to...

Taliban Denies Talks With Pakistan on Afghan Peace Prospects

Taliban Denies Talks With Pakistan on Afghan Peace Prospects..

24-Mar, 07:08

FILE - Taliban fighters react to a speech by their senior leader in the...

Chechnya: Russian soldiers killed in clash with insurgents

Chechnya: Russian soldiers killed in clash with insurgents..

24-Mar, 06:58

Six Russian soldiers have been killed and several wounded in a clash with...

Islamic State vows more attacks on Egypt's Christians

Islamic State vows more attacks on Egypt's Christians..

20-Feb, 06:50

An Islamic State affiliate in Egypt has released a new video showing the...

French election: conservative candidate Fillon refuses to step down despite fake jobs investigation

French election: conservative candidate Fillon refuses to step down despite fake jobs..

01-Mar, 06:48

French election: conservative candidate Fillon refuses to step down...

My Bromance The Series Episode 12

My Bromance The Series Episode 12..

03-Mar, 04:27

The following My Bromance The Series Episode 12 English Sub has been...

dansui Episode 4

dansui Episode 4..

21-Feb, 03:59

The following dansui Episode 4 English Sub has been released. Full HD...