MELTING GLACIERS

The danger posed to the global habitat by posed by human-induced climate change is real, but the political response is not in proportion.

Yet the evidence would appear to be overwhelming that the earth’s glaciers are melting. Scientists, using satellite date, have estimated that 1,000 cubic miles of ice from polar ice sheets, ice-caps and mountain glaciers over the entire globe have been removed from 2003 to 2010. Previously the effect of glacier melting had been overestimated. Steve  Connor in The Independent reports:

Experiment (GRACE), a joint satellite project run by Nasa and the German government, also found that the amount of ice melting from the mountain glaciers and ice caps that were not in Greenland or Antarctica was actually significantly smaller than previous estimates had suggested.

Instead of contributing nearly 1mm of sea level rise per year as previously suggested, some of the Earth’s glaciers and ice caps, especially in the Himalayas and other mountain ranges in Asia, were melting significantly slower than expected, contributing about 0.4mm of sea level rise per year – less than half the amount predicted.

One explanation for the previous overestimates could be that most of the glaciers that have been studied intensively are at lower altitudes and therefore more prone to melting. Higher glaciers are colder and less susceptible and yet only 120 glaciers out of 160,000 glaciers and ice caps have been directly measured from the ground.

The GRACE satellite experiment, however, covered the entire globe and found that all the world’s glaciers and ice caps combined, apart for those in Greenland and Antarctica, had lost about 148 billion tonnes of ice, or about 39 cubic miles, annually between 2003 and 2010. The individual glaciers on the fringes of Greenland and Antarctic contributed an additional 80 billion tons over the same period, the study published in Nature found.

The satellite data confirms the comparative photographic evidence of glaciers in the Himalayas and Central Asia:

Evidence is one thing. The taking of appropriate and timely action is another.

Related articles

• CU-Boulder study shows global glaciers, ice caps, shedding billions of tons of mass annually (eurekalert.org)
• Impact of climate change on the Himalaya far less than estimated (gadling.com)
• NASA Satellites Show How Our Icy World Is Melting (space.com)
• Melting ice sheets already seen driving sea-level rise. (eenews.net)

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