Ice sheets are melting faster than thought

If what is happening now continues, ice sheets will be a major source of rising sea levels.
Written by Boonsri Dickinson, Contributing Editor

The Greenland and Antarctic ice sheets are melting very very quickly. The ice mass is melting at an accelerating pace... making it a leading source of sea level rise.

Eric Rignot, of NASA's Jet Propulsion Laboratory, Pasadena, California, said in a statement:

"That ice sheets will dominate future sea level rise is not surprising -- they hold a lot more ice mass than mountain glaciers. What is surprising is this increased contribution by the ice sheets is already happening. If present trends continue, sea level is likely to be significantly higher than levels projected by the United Nations Intergovernmental Panel on Climate Change in 2007. Our study helps reduce uncertainties in near-term projections of sea level rise."

The study will be published soon in Geophysical Research Letters. The results were based on two independent measurements, which included 18 years of satellite and modeling data taken from both regions. The numbers tell the story: the ice loss is happening very quickly. The Greenland ice sheets lost mass faster than the previous year by 21.9 gigatonnes a year. And the loss seen in Antarctica was on average 14.5 gigatonnes a year, compared to the previous year.

As far as predicting ice loss in the future, at least one thing is for sure... it's uncertain. At this rate though, considering the impact from other factors, the total sea level rise could be as high as 32 centimeters by 2050.

Photo: Eric Rignot, JPL

This post was originally published on Smartplanet.com

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