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Study: Greenland ice loss accelerating

By Doyle Rice, USA TODAY

The Greenland ice sheet, the world's second-largest, is continuing to experience ice loss due to global warming, according to a new study.

What's new about this study is that the ice loss, which has been well-documented over southern Greenland, is now spreading up along the northwest coast, with this acceleration likely starting in late 2005.

"The changes on the Greenland ice sheet are happening fast, and we are definitely losing more ice mass than we had anticipated," says study co-author Isabella Velicogna of the University of California-Irvine. "We also are seeing this trend in Antarctica, a sign that warming temperatures really are having an effect on ice in Earth's cold regions."

Air temperatures over the Greenland ice sheet have increased by about 4 degrees since 1991, which most scientists attribute to a buildup of greenhouse gases such as carbon dioxide in the Earth's atmosphere.

"This is a phenomenon that was undocumented before this study," study co-author John Wahr of the University of Colorado says.  "Our speculation is that some of the big glaciers in this region are sliding downhill faster and dumping more ice in the ocean."

Scientists used a combination of satellite and GPS measurements to document the ice loss.

The mass loss is equivalent to about 0.02 inch of global sea-level rise per year. If the entire Greenland ice sheet melted, which is not predicted, scientists estimate that global sea levels would rise about 20 feet, according to the National Snow and Ice Data Center.

The Greenland ice sheet covers most of the island, and is about 656,000 square miles in size, roughly three times the size of Texas.

The paper was published this month in Geophysical Research Letters, a publication of the American Geophysical Union.

This video is a simulation of the ice melt, provided by the University of Colorado.

By Doyle Rice

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