What are the implications of the massive thaw that is taking place right now in Western Siberia?

Russian researchers returned from an exploratory mission in Western Siberia last year to report that the world’s largest frozen peat bog there, land as large as France and Germany combined, was quickly melting away "into shallow lakes." Sergei Kirpotin, a botanist at Russia’s Tomsk State University and the leader of the research effort, told the journal New Scientist that the situation was an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming."

The main worry is that as much as a billion tons of methane--a "greenhouse gas" 20 times more potent than carbon dioxide--could be rapidly released from the bog, where it has been sitting harmlessly for thousands of years. This flush of methane into the atmosphere could, in turn, further warm the atmosphere.

Western Siberia has warmed faster than almost any other area of the planet, with an average temperature increase of about three degrees Celsius over the last four decades alone. Kirpotin believes that man-made climate change, combined with cyclical changes in atmospheric circulation caused by melting ice, is to blame. Similar patterns are developing in Eastern Siberia and across the Arctic stretches of Alaska.

Siberia’s peat bogs formed about 11,000 years ago at the end of the last ice age. The huge bog in question is thought to contain 70 billion tons of methane, or about a quarter of all the methane stored on the Earth’s surface worldwide. If it continues to thaw, as it seems likely to do, researchers fear that the methane could force a "tipping point" (point of no return) in the ability of the Earth’s climate to regulate itself.

"When you start messing around with these natural systems, you can end up in situations where it’s unstoppable," says climate researcher David Viner of England’s University of East Anglia. "This is a big deal because you can’t put the permafrost back once it is gone."

In 2001, the Intergovernmental Panel on Climate Change, an international group of climate researchers, estimated that global temperatures could rise as much as 5.8 degrees Celsius by 2100, thanks to known sources of greenhouse gas emissions. According to Viner, scientists did not even anticipate the possibility of events like this when making their predictions, and how much they could add to the warming.

Environmentalists are using the Western Siberia findings to step up pressure on world leaders to take concerted action on climate change. Says Tony Juniper, director of Friends of the Earth in the United Kingdom: "If we don’t take action very soon, we could unleash runaway global warming that will be beyond our control and it will lead to social, economic and environmental devastation worldwide. There’s still time to take action, but not much."

CONTACT: New Scientist, www.newscientist.com/article.ns?id=mg18725124.500.

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