Antarctica data maybe bad news UM scientists envision cold continent’s warming

New research by a team of international scientists, including several from the University of Maine, shows that rising global temperatures have not significantly changed weather patterns in the interior regions of Antarctica.

But researchers cautioned against interpreting the data as good news on climate change. Instead, they said the lack of additional snowfall over interior Antarctica – coupled with more alarming news on melting ice sheets in Greenland – could mean that global warming could have even more severe impacts than previously thought.

Sixteen researchers, including Paul Mayewski of UMaine’s Climate Change Institute, used ice core samples and models to analyze annual snowfall in Antarctica during the past 50 years. Two UMaine graduate students, Daniel Dixon and Susan Kaspari, also worked on the study.

Contrary to popular perceptions of Antarctica as a snowy hell, much of the interior of the continent is considered a “polar desert” and therefore receives relatively little precipitation. The extreme cold merely keeps snow and ice from ever melting.

Climatologists and polar researchers have predicted that rising global temperatures caused by human-induced buildup of carbon dioxide in the atmosphere will increase moisture levels above Antarctica because warmer air holds more moisture.

More moisture above Antarctica should translate into more snowfall over the continent. This is important because one prominent scientific theory predicts that this additional snow will help thicken the Antarctic ice sheets, thereby helping slow a rise in sea levels worldwide.

But the researchers, who published their work this week in the journal Science, found no “statistically significant global warming signal of increasing precipitation over Antarctica” during the past five decades.

Another scientific study published in the same edition of Science reports that the Greenland ice sheets are melting much faster than previously believed.

Mayewski, a world-renowned expert on climate change, said during an interview Friday that parts of Antarctica already are experiencing the effects of global warming.

Coastal glaciers have been retreating for several decades, floating ice areas are collapsing, and marine air masses are traveling farther inland, he said. At the same time, global temperatures and sea levels are rising.

The fact that precipitation levels in interior Antarctica have not changed could suggest that Antarctica is setting up for a “significant climate change” once the weather patterns finally shift, he said. Antarctica is one of the last parts of the globe that will be affected by climate change, Mayewski said.

“All we are saying is the [global warming] process has not come into the interior yet, therefore the warming we have experienced so far is a subdued version of what we will see in the future,” said Mayewski, who heads the international scientific expedition that gathered the ice cores.

The study also will provide a baseline of information to gauge future precipitation and climate change, he said.

The study’s lead author, meteorologist Andrew Monaghan with Ohio State University’s Byrd Polar Research Center, said the findings suggest that scientists may not be able to count on Antarctica to mitigate the rising sea levels from melting glaciers and ice sheets.

Monaghan said more long-range study is needed to determine global warming’s impact on all of Antarctica’s ice sheets. But he said it would be “quite a misinterpretation” of the group’s findings to read it as evidence against global warming.

The director of UMaine’s Climate Change Institute, Mayewski has led more than 35 expeditions to Antarctica and other remote portions of the globe. He said Friday that he is preparing for another two- to three-month expedition beginning this November to collect more ice cores in Antarctica.