Greenland And West Antarctic Ice Sheet Loss More Than Doubled In Last Five Years

http://thinkprogress.org/climate/2014/08/22/3474657/greenland-west-antarctic-ice-sheet-loss/

by Joe Romm Posted on August 22, 2014

A new study finds that both the Greenland ice sheet and West Antarctic Ice Sheet (WAIS) have seen an astonishing increase in ice loss in just the past five years.

This first-ever extensive mapping of the two great ice sheets using the CryoSat-2 satellite confirms the findings of several recent studies that “suggest that the globe’s ice sheets will contribute far more to sea level rise than current projections show,” as NASA glaciologist Eric Rignot said recently.

Comparing the current CryoSat-2 data with “those from the ICESat satellite from the year 2009, the volume loss in Greenland has doubled since then.” Coauthor and glaciologist Prof. Dr. Angelika Humbert further explained in the news release:

“The loss of the West Antarctic Ice Sheet has in the same time span increased by a factor of 3. Combined the two ice sheets are thinning at a rate of 500 cubic kilometres per year. That is the highest speed observed since altimetry satellite records began about 20 years ago.”

So we are at record rates of ice loss now. What is particularly stunning is that a major international study found in 2012 that Greenalnd’s ice loss was up by a factor of five since the mid-90s, while Antartica’s was up 50 percent in the prior decade.

We are seeing ice sheet loss at rates not imagined even a few years ago. Back in May, two studies provided evidence that the West Antarctic Ice Sheet has begun an irreversible process of collapse, in part because its key glaciers are grounded below sea level and are melting from underneath.

Also in May, a team of researchers reported that the Greenland ice sheet has a similar warming-driven instability. As a lead author of that study explained, “The glaciers of Greenland are likely to retreat faster and farther inland than anticipated — and for much longer.”

It’s increasingly clear that if we don’t reverse carbon pollution emissions trends ASAP, sea level rise will likely be 4 to 5 feet or more by century’s end. Also, the rate of sea level rise in 2100 could be upwards of 1 inch per year.

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