Greenland ice melt seen at lower temperatures: study

LONDON Sun Mar 11, 2012 3:00pm EDT

An iceberg floats in the sea ice near the town of Uummannaq in western Greenland March 18, 2010. REUTERS/Svebor Kranjc

An iceberg floats in the sea ice near the town of Uummannaq in western Greenland March 18, 2010.

Credit: Reuters/Svebor Kranjc

Related Topics

LONDON (Reuters) - The complete melt of the Greenland ice sheet could occur at lower global temperatures than previously thought, a study in the journal Nature Climate Change showed on Sunday, increasing the threat and severity of a rise in sea level.

Substantial melting of land ice could contribute to long-term sea level rise of several meters, potentially threatening the lives of millions of people.

"Our study shows that a temperature threshold for melting the (ice sheet) exists and that this threshold has been overestimated until now," said scientists at the Potsdam Institute for Climate Impact Research and the Universidad Complutense de Madrid, who used computer simulations of the ice sheet's evolution to predict its future behavior.

A complete ice sheet melt could happen if global temperatures rose between 0.8 and 3.2 degrees Celsius above pre-industrial levels, with a best estimate of 1.6 degrees, the scientists said.

Previous research has suggested the ice sheet could melt in a range of a 1.9 to 5.1 degree temperature rise, with a best estimate of 3.1 degrees.

One-twentieth of the world's ice is in Greenland, which is about a quarter of the size of the United States and about 80 percent of it is covered by the ice sheet. If it all melted it would be equivalent to a 6.4 meter global sea level rise, previous research has shown.

"If the global temperature significantly overshoots the threshold for a long time, the ice will continue melting and not regrow - even if the climate would, after many thousand years, return to its pre-industrial state," said team leader Andrey Ganopolski at the Potsdam Institute for Climate Impact Research.

Today, global warming of 0.8 degrees has already been recorded.

"The more we exceed the threshold, the faster it melts," said Alexander Robinson, lead-author of the study.

If the world takes no action to limit greenhouse gas emissions, the earth could warm by 8 degrees Celsius.

"This would result in one fifth of the ice sheet melting within 500 years and a complete loss in 2,000 years," he said.

"This is not what one would call a rapid collapse. However, compared to what has happened in our planet's history, it is fast. And we might already be approaching the critical threshold.

If temperature rise is limited to 2 degrees Celsius, a complete melt of the ice sheet could happen in 50,000 years, the study found.

(Reporting by Nina Chestney; Editing by Karolina Tagaris)

FILED UNDER:
We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see http://blogs.reuters.com/fulldisclosure/2010/09/27/toward-a-more-thoughtful-conversation-on-stories/
Comments (1)
meleze wrote:
Nobody cares anymore of that question. Europe has put a carbon tax on the airflights and China the richest country in the world refuses to pay it, followed by Russia and the United States. The world is commiting to suicide. For the next three months there is a vague concern about the meeting Rio + 20 because it may help Obama in the hypothesis he would go on as president of the USA. But if he failed the UN would be hold by a new Boulton.

Mar 15, 2012 5:44pm EDT  --  Report as abuse
This discussion is now closed. We welcome comments on our articles for a limited period after their publication.

Photo

California's historic drought

With reservoirs at record lows, California is in the midst of the worst drought in decades.  Slideshow