[Vision2020] New Study In "Nature" On Thawing Permafrost & Methane

[Ted Moffett]

Updated: 02:27 AM EDT

New Climate Change 'Time Bomb' Detected
Melting Permafrost Frees More Gases That Trap Heat
By SETH BORENSTEIN, AP

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WASHINGTON (Sept. 7) - Global warming gases trapped in the soil are bubbling
out of the thawing permafrost in amounts far higher than previously thought
and may trigger what researchers warn is a climate time bomb.

Methane - a greenhouse gas 23 times more powerful than carbon dioxide - is
being released from the permafrost at a rate five times faster than thought,
according to a study being published Thursday in the journal Nature. The
findings are based on new, more accurate measuring techniques.

"The effects can be huge," said lead author Katey Walter of the University
of Alaska at Fairbanks said. "It's coming out a lot and there's a lot more
to come out."

Scientists worry about a global warming vicious cycle that was not part of
their already gloomy climate forecast: Warming already under way thaws
permafrost, soil that has been continuously frozen for thousands of years.
Thawed permafrost releases methane and carbon dioxide. Those gases reach the
atmosphere and help trap heat on Earth in the greenhouse effect. The trapped
heat thaws more permafrost and so on.

"The higher the temperature gets, the more permafrost we melt, the more
tendency it is to become a more vicious cycle," said Chris Field, director
of global ecology at the Carnegie Institution of Washington, who was not
part of the study. "That's the thing that is scary about this whole thing.
There are lots of mechanisms that tend to be self-perpetuating and
relatively few that tend to shut it off."

Some scientists say this vicious cycle is already under way, but others
disagree.

Most of the methane -releasing permafrost is in Siberia. Another study
earlier this summer in the journal Science found that the amount of carbon
trapped in this type of permafrost - called yedoma - is much more prevalent
than originally thought and may be 100 times the amount of carbon released
into the air each year by the burning of fossil fuels.

It won't all come out at once or even over several decades, but if
temperatures increase, then the methane and carbon dioxide will escape the
soil, scientists say.

The permafrost issue has caused a quiet buzz of concern among climate
scientists and geologists. Specialists in Arctic climate are coming up with
research plans to study the permafrost effect, which is not well understood
or observed, said Robert Corell, chairman of the Arctic Climate Impact
Assessment, a study group of 300 scientists.

"It's kind of like a slow-motion time bomb," said Ted Schuur, a professor of
ecosystem ecology at the University of Florida and co-author of the study in
Science.

Most of the yedoma is in little-studied areas of northern and eastern
Siberia. What makes that permafrost special is that much of it lies under
lakes; the carbon below gets released as methane . Carbon beneath dry
permafrost is released as carbon dioxide.

Using special underwater bubble traps, Walter and her colleagues found giant
hot spots of bubbling methane that were never measured before because they
were hard to reach.

"I don't think it can be easily stopped; we'd really have to have major
cooling for it to stop," Walter said.

Scientists aren't quite sure whether methane or carbon dioxide is worse.
Methane is far more powerful in trapping heat, but only lasts about a decade
before it dissipates into carbon dioxide and other chemicals. Carbon dioxide
traps heat for about a century.

"The bottom line is it's better if it stays frozen in the ground," Schuur
said. "But we're getting to the point where it's going more and more into
the atmosphere."

Vladimir Romanovsky, geophysics professor at the University of Alaska at
Fairbanks, said he thinks the big methane or carbon dioxide release hasn't
started yet, but it's coming. In Alaska and Canada - which have far less
permafrost than Siberia - it's closer to happening, he said. Already, the
Alaskan permafrost is reaching the thawing point in many areas.
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