Thursday, February 9, 2012

NASA GRACE: Global Warming Melts Billions of Tons of Ice Annually (VIDEO)



Researchers from NASA and the University of Colorado Boulder have discovered that glaciers and ice caps are shedding 150 billion tons of ice annually because of global warming. They discovered this using Gravity Recovery and Climate Experiment (GRACE) satellites.

The researchers measured ice loss percentages across all of Earth's ice reserves between 2003 and 2010, with particular emphasis on glaciers and ice caps outside of Greenland and Antarctica.

They discovered that these geological formations were shedding roughly 150 billion tons of ice annually. The most alarming conclusion was that ice caps and glaciers from within Greenland and Antarctica were shedding 385 billion tons (100 cubic miles) of ice every year.

Credit: NASA/JPL-Caltech/University of Colorado 

Average changes in ice thickness in centimeters per year from 2003 to 2010, as measured by NASA’s Grace satellites, in each of the world’s ice caps and glacier systems outside of Greenland and Antarctica. Blue represents ice mass loss, while red represents ice mass gain.

The study also suggested that mountains on the Asian continent - the Himalayas, the Pamir and the Tien Shan - were shedding approximately 4 billion tons of ice annually.

As strange as it may sound, this figure actually comes as a relief. Earlier ground-based estimates suggested ice loss in high Asian mountains may range up to 50 billion tons, annually.

The total ice loss from Greenland, Antarctica and all of Earth's glaciers and ice caps from 2003 to 2010 was about 4.3 trillion tons (1,000 cubic miles) which is about eight times the water volume of Lake Erie in the U.S.

These measurements were made with the NASA-developed GRACE satellite. GRACE was launched in 2002 and is a twin satellite that measure changes in the Earth's gravity field, as caused by regional changes in the planet's mass, including ice sheets, oceans and water stored in the soil and in underground aquifers.

"Earth is losing a huge amount of ice to the ocean annually, and these new results will help us answer important questions in terms of both sea rise and how the planet's cold regions are responding to global change," said John Wahr, a Professor at the University of Colorado Boulder.

"One possible explanation is that previous estimates were based on measurements taken primarily from some of the lower, more accessible glaciers in Asia and extrapolated to infer the behaviour of higher glaciers. But unlike the lower glaciers, most of the high glaciers are located in very cold environments and require greater amounts of atmospheric warming before local temperatures rise enough to cause significant melting. This makes it difficult to use low-elevation, ground-based measurements to estimate results from the entire system," he added.

"This study finds that the world's small glaciers and ice caps in places like Alaska, South America and the Himalayas contribute about .02 inches per year to sea level rise," said Tom Wagner, a program scientist at NASA Headquarters in Washington, "While this is lower than previous estimates, it confirms that ice is being lost from around the globe, with just a few areas in precarious balance. The results sharpen our view of land ice melting, which poses the biggest, most threatening factor in future sea level rise."

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