One of the major concerns of climate change is the potential increase in sea level resulting from the melting of the Antarctic and Greenland ice sheets.
New research from a team of scientists at Ohio State University, published in the journal Nature Geoscience, suggests that levels of warming in the Western Antarctic Ice Sheet (WAIS) are much higher than previously thought.
Climate Change, Ice Sheets, and Rising Sea Levels
Many agencies have reported the increasing loss of Arctic sea: the NOAA’s 2012 Arctic Report Card refers to “record low snow extent and low sea ice extent occurred in June and September, respectively.”
But although loss of sea ice has implications for climate, it’s melting of the ice caps which is the major contributor to sea level rise, as water which has been locked up in the form of ice (the cryosphere) is released into the sea.
The WAIS is already significant in this respect. “It contributes about 0.3 mm/year to current sea level rise, roughly 10% of the total,” the study’s lead author Professor David Bromwich told Decoded Science. “Our results suggest that in a few decades West Antarctica could contribute significantly more to sea level rise than today as a consequence of the impact of much greater ice shelf melting (at low elevations).”
Ice Sheets Melting: Key Findings of the Study
Because of the hostile nature of the terrain, there is a scarcity of long-term climate data in the WAIS: the study notes that “assessing Antarctic climate change on timescales of a few decades is a well-recognized challenge.” The researchers assessed available data from the WAIS’s Byrd Station and used various statistical techniques to correct existing data and produce a data series covering 56 years.
The results show that the WAIS is warming, especially during the southern hemisphere summer, at a rate which is among the highest on the plant. “ observations have a broad spatial relevance,” said Professor Bromwich. “There are no comparable weather observations in the area that cover anything like 50 years. For very recent times, there are a number of sites around Byrd Station that show good agreement with its data. Our results confirm findings … from extrapolation of distant observations but give much larger warming rates.”
Global Warming? Implications for the Future
The research did not reach any conclusions about the causes of the warming, though the study notes that warming during the late 1980s coincided with changes in atmospheric pressure systems and a decrease in summer sea ice, the data failed to produce any clear evidence to link warming to these changes.
The warming patterns established as a result of the enhanced data do, however, provide strong support for a further program of research in future.
“Our research suggests that surface melting could become much more important in the future with important impacts on the ice sheet’s contribution to sea level, as mentioned above,” said Professor Bromwich.
And, as the study concludes, the results “argue for a robust long-term meteorological observation network in the region.”
Bromwich, D.H. et al. Central West Antarctica among the most rapidly warming regions on Earth. (2012). Nature Geoscience. Accessed December 23, 2012.
NOAA. Arctic report card: Update for 2012. (2012). Accessed December 23, 2012