A new Antarctic ice sheet study from NASA yielded surprising data results, and the findings contradict the conclusion of a previous report from the Intergovernmental Panel on Climate Change (IPCC). As reported by Tech Times, the study shows that increased accumulation of snow in Antarctica, which began 10,000 years ago, is continuing to increase the amount of ice on the continent, and compensates for the loss of glaciers. The research is significant because it challenges the findings of a number of studies, including those cited by the IPCC. The IPCC report from 2013 says that the Antarctic land ice is declining.
According to satellite data, the Antarctic ice sheet shows a clear increase of 112 billion tons of ice annually from 1992 to 2001, while the total loss between 2003 and 2008 was only 82 billion tons. Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, issued the following statement regarding the study.
“We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica. Our main disagreement is for East Antarctica and the interior of West Antarctica — there, we see an ice gain that exceeds the losses in the other areas.”
In the NASA report, Zwally added that his team has measured small variations in height over large areas, and “if the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years — I don’t think there will be enough snowfall increase to offset these losses.”
The study analyzed the variations in the surface of the Antarctic ice sheet thanks to two satellites — the European Space Agency European Remote Sensing (ERS) satellite and the laser altimeter on NASA’s Ice, Cloud, and land Elevation Satellite (ICESat).
The Antarctic Peninsula is the northernmost part of the mainland of Antarctica, rising to the northwest toward the southern tip of South America. Temperatures exceed 0°C for three to four months of austral summer, and rarely fall below -10°C during austral winter, according to Encyclopedia of Earth. Since the late 1940s, the average temperature of the Antarctic Peninsula has increased by 0.5°C per decade, a significant and rapid increase which is believed to be part of the global warming of the earth. Now, what is happening in this area is often taken as evidence of global warming. The truth is that the length of available temperature data is short — most records begin in 1957 — and the findings are usually presented in the media as a disaster. But if Antarctica is to be viewed as a whole, it looks somewhat different.
At the end of the last Ice Age, the air became warmer and carried more moisture on the continent, doubling the amount of snow given the expanse of ice. The intense snowfall that began 10,000 years ago has accumulated slowly and is compacted into solid ice over millennia, thickening the ice in East Antarctica and the interior of West Antarctica by an average of 0.7 inches (1.7 centimeters) per year. This thickening, says NASA, has continued for thousands of years and has spread to large parts of Antarctica and corresponds to a large increase of ice, enough to overcome the negative value of the loss of glaciers in other areas and reduce global sea level rise.
“The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away,” Zwally explained. “But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for.”
[Image via Frances M. Ginter / Hulton Archive]