The Big Melt

A two-year polar survey finds ice sheets melting faster than expected, and more grim news

Less than two weeks before scientists from around the world gather in Copenhagen to issue recommendations for a new global climate-change treaty, the results from the two-year International Polar Year survey have arrived. They are not pleasant.

Here's a quick summary: The Antarctic and Greenland ice shelves are melting more quickly than we realized. Year-round Arctic sea-ice levels reached their lowest levels in 30 years, which is how long we've been keeping records. The seawater beneath Antarctica is freshening, which indicates ice melt. Global ocean currents are beginning to shift. "We're beginning to get hints of change in ocean circulation; that'll have a dramatic impact on the global climate system," IPY director David Carlson told reporters in Geneva.

During the survey, scientists found larger-than-expected pools of methane (which, like carbon dioxide, is a greenhouse gas) frozen into the Arctic permafrost. And scientists in Siberia actually detected "substantial" methane emissions from melting permafrost.

The International Polar Year began in March 2007 and consisted of 160 individual projects in 60 countries. Its findings will surely be a part of the conversation at the Copenhagen Climate Change congress March 10 to 12. We'll be there covering it, and we'll let you know.

[Via Agence France-Presse]

image: pulsating pack-ice graph compiled by Uwe Kils from SeaWiFS images