A new study by NASA has found that Antarctica is gaining ice at a rate that is higher than it is losing it. This challenges other research, which includes that of the Intergovernmental Panel for Climate Change of the United Nations that says the southern continent on Earth is losing land ice.
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Researchers at Sigma Space Corporation – an engineering company – and at NASA’s Goddard Space Flight Center, the University of Maryland in College Park have satellite data that proves the Antarctic sheet has gained 112 billion tons of ice per year from 1992 to 2001. That extra coating adds up to an extra 200 billion tons of ice annually from 1992 to 2008, they found. At the same time, the ice loss on the western and coastal region has increased by an additional 65 tons per year, they found.
This confusion was echoed by Jay Zwally, lead author of the paper – “Mass gains of the Antarctic ice sheet exceed losses”- and NASA glaciologist, in a press-release. According to the computer simulations, a few decades of ocean warming can start an ice loss that continues for centuries or even millennia.
Many scientists agree that the Antarctic Peninsula and parts of West Antarctica are losing ice and that the rate of loss is increasing.
More than that, though, Zwelly used data from satellites that weren’t built to measure changes in ice in such fine detail.
This small thickening, sustained over thousands of years and spread over the vast expanse of these sectors of Antarctica, corresponds to a very large gain of ice – enough to outweigh the losses from fast-flowing glaciers in other parts of the continent and reduce global sea level rise.
This increase in ice is actually contributing to a reduction in sea level by 0.23 milimeters per year.
“But this is also bad news”, he voiced concern.
The data show that a long, 10,000-year process of snowfall accumulation that began at the end of the last Ice Age has been consistently thickening the ice by an average of 1.7 centimeters per year. These new results are consistent with those of past studies, which confirm that the stability of West Antarctica’s ice crust in could be irrevocably disturbed.
Regardless, it is clear that continuing greenhouse gas emissions will increase the risk of ice system collapse in the West Antarctic along with resulting sea level rise, explained Anders Levermann, a co-author of the study who also worked at the World Climate Report (IPCC).
The future evolution of the Antarctic Ice Sheet represents the largest uncertainty in sea-level projections of this and upcoming centuries.
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The team believes that the significance of the new findings is such, that it will force scientists to rethink models that attempt to account for sea level rise.
