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Thawing Permafrost Vents Gases to Worsen Warming


This handout photo, taken in 2009, provided by University of Alaska, Fairbanks, shows research assistant professor Katey Walter Anthony igniting trapped methane from under the ice in a pond on the Fairbanks campus. Massive amounts of greenhouse gases trapped below thawing permafrost will likely vent into the air over the next several decades, accelerating and amplifying global warming, scientists warn.
(AP Photo/Todd Paris, University of Alaska, Fairbanks)

By SETH BORENSTEIN AP Science Writer
WASHINGTON November 30, 2011 (AP)

Massive amounts of greenhouse gases trapped below thawing permafrost will likely seep into the air over the next several decades, accelerating and amplifying global warming, scientists warn.

Those heat-trapping gases under the frozen Arctic ground may be a bigger factor in global warming than the cutting down of forests, and a scenario that climate scientists hadn't quite accounted for, according to a group of permafrost experts. The gases won't contribute as much as pollution from power plants, cars, trucks and planes, though.

The permafrost scientists predict that over the next three decades a total of about 45 billion metric tons of carbon from methane and carbon dioxide will seep into the atmosphere when permafrost thaws during summers. That's about the same amount of heat-trapping gas the world spews during five years of burning coal, gas and other fossil fuels

And the picture is even more alarming for the end of the century. The scientists calculate that about than 300 billion metric tons of carbon will belch from the thawing Earth from now until 2100.

Adding in that gas means that warming would happen "20 to 30 percent faster than from fossil fuel emissions alone," said Edward Schuur of the University of Florida. "You are significantly speeding things up by releasing this carbon."

Usually the first few to several inches of permafrost thaw in the summer, but scientists are now looking at up to 10 feet of soft unfrozen ground because of warmer temperatures, he said. The gases come from decaying plants that have been stuck below frozen ground for millennia.

Schuur and 40 other scientists in the Permafrost Carbon Research Network met this summer and jointly wrote up their findings, which were published [ http://www.nature.com/nature/journal/v480/n7375/full/480032a.html ] in the journal Nature on Wednesday.

"The survey provides an important warning that global climate warming is likely to be worse than expected," said Jay Zwally, a NASA polar scientist who wasn't part of the study. "Arctic permafrost has been like a wild card."

When the Nobel Prize-winning panel of climate scientists issued its last full report in 2007, it didn't even factor in trapped methane and carbon dioxide from beneath the permafrost. Diplomats are meeting this week in South Africa to find ways of curbing human-made climate change.

Schuur and others said increasing amounts of greenhouse gas are seeping out of permafrost each year. Some is methane, which is 25 times stronger than carbon dioxide in trapping heat.

In a recent video, University of Alaska Fairbanks professor Katey Walter Anthony, a study co-author, is shown setting leaking methane gas on fire with flames shooting far above her head.

"Places like that are all around," Anthony said in a phone interview. "We're tapping into old carbon that has been locked up in the ground for 30,000 to 40,000 years."

That triggers what Anthony and other scientists call a feedback cycle. The world warms, mostly because of human-made greenhouse gases. That thaws permafrost, releasing more natural greenhouse gas, augmenting the warming.

There are lots of unknowns and a large margin of error because this is a relatively new issue with limited data available, the scientists acknowledge.

"It's very much a seat-of-the-pants expert assessment," said Stanford University's Chris Field, who wasn't involved in the new report.

The World Meteorological Organization this week said the worst of the warming in 2011 was in the northern areas — where there is permafrost — and especially Russia. Since 1970, the Arctic has warmed at a rate twice as fast as the rest of the globe.

The thawing permafrost also causes trees to lean — scientists call them "drunken trees" — and roads to buckle. Study co-author F. Stuart Chapin III said when he first moved to Fairbanks the road from his house to the University of Alaska had to be resurfaced once a decade.

"Now it gets resurfaced every year due to thawing permafrost," Chapin said.

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Online:

Nature: http://www.nature.com/nature

Permafrost network: http://www.biology.ufl.edu/permafrostcarbon/index.html

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Copyright 2011 The Associated Press

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Permafrost Thaw May Emit More Than Deforestation, Study Says

By Alex Morales - Nov 30, 2011 12:00 PM CT

Emissions from thawing permafrost may contribute more to global warming than deforestation this century, according to a commentary in the journal Nature.

Arctic warming of 7.5 degrees Celsius (13.5 degrees Fahrenheit) this century may unlock the equivalent of 380 billion tons of carbon dioxide as soils thaw, allowing carbon to escape as CO2 and methane, University of Florida and University of Alaska biologists wrote today in Nature. Two degrees of warming would release a third of that, they said.

“We calculate that permafrost thaw will release the same order of magnitude of carbon as deforestation if current rates of deforestation continue,” the researchers said. “Because these emissions include significant quantities of methane, the overall effect on climate could be 2.5 times larger.”

The Arctic is an important harbinger of climate change because the United Nations calculates it’s warming at almost twice the average rate for the planet. The study adds to pressure on United Nations climate treaty negotiators from more than 190 countries attending two weeks of talks in Durban, South Africa that began Nov. 28.

The International Energy Agency this month said with current energy policies worldwide, the global average temperature may rise by more than 3.5 degrees. With the Arctic warming faster than the rest of the world, that could imply a 7- degree rise in the region. The Arctic warming has led to record melting of sea ice in recent years and the retreat of glaciers in Greenland.

Warming Scenarios

The researchers based their commentary on a survey of 41 permafrost scientists from around the world, who were asked to calculate what percentage of the surface permafrost is likely to thaw, how much carbon will be released, and how much of that carbon will be methane over different time frames and for four different warming scenarios.

“Our survey outlines the additional risk to society caused by thawing of the frozen north, and underscores the urgent need to reduce atmospheric emissions from fossil-fuel use and deforestation,” the scientists said. “This will help to keep permafrost carbon frozen in the ground.”

Researchers at the Permafrost Carbon Research Network also contributed to the commentary piece.

To contact the reporter on this story: Alex Morales in Durban, South Africa via [e-mail].
To contact the editor responsible for this story: Reed Landberg via [e-mail].

©2011 BLOOMBERG L.P.

http://www.bloomberg.com/news/2011-11-30/permafrost-thaw-may-emit-more-than-deforestation-study-says.html