Forest, Wildlife, and Climate News

Antarctica: Warming, Cooling, or Both?

The ice caps are melting – right? If you visit thousands of websites on climate change, watch Gore’s film or many similar documentaries, you would be left with no doubt that the icecaps are warming and melting at an unprecedented rate. However, with respect to Antarctica, you might be surprised when you examine what the United Nations Intergovernmental Panel on Climate Change says in their 2007 Summary for Policymakers. Believe it or not, IPCC reports “Antarctic sea ice extent continues to show inter-annual variability and localized changes but no statistically significant average trends, consistent with the lack of warming reflected in atmospheric temperatures averaged across the region.” Furthermore, they note “Current global model studies project that the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall.”

A major article on this subject appears in a recent issue of the Journal of Climate by William Chapman and John Walsh of the University of Illinois. The two scientists extensively review the literature on temperature trends in Antarctica and conclude “These studies are essentially unanimous in their finding that the Antarctic Peninsula has warmed since the 1950s, when many of the surface stations were established.” They note “Recent summaries of station data show that, aside from the Antarctic Peninsula and the McMurdo area, one is hard-pressed to argue that warming has occurred, even at the Antarctic coastal stations away from the peninsula and McMurdo.” Furthermore, they write “Recent attempts to broaden the spatial coverage of temperature estimates have shown a similar lack of evidence of spatially widespread warming.” Like it or not, over the past four decades, and during the time of the greatest build-up of greenhouse gases, Antarctica has been cooling! … [more]