The Associated Press, Dec. 1, 2011
WASHINGTON — 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 in the journal Nature.
"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 was not 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 did not 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.
Copyright 2011 The Associated Press. All rights reserved.
Fairbanks Daily News-Miner (Alaska), Dec. 1, 2011
FAIRBANKS — An international group of researchers believes greenhouse gases from thawing permafrost will be released at a much faster rate than previously estimated, which could have significant implications for climate change projections.
A survey of 41 scientists — including seven University of Alaska Fairbanks researchers — estimates the amount of carbon released from thawing permafrost by 2100 will be 1.7 to 5.2 times larger than previously estimated. Their conclusions, reported Wednesday in the scientific journal Nature, describe permafrost thawing as a likely accelerator of global warming.
“Our collective estimate is that carbon will be released more quickly than models suggest, and at levels that are cause for serious concern,” the article states.
The higher figures come about because of an ongoing reevaluation of the carbon stored in permafrost.
In most soils such material is typically in the top several feet, but in frozen soils those carbon-filled sediments can be much deeper.
Because of that, the estimated amount of carbon stored in northern soils has tripled in recent years, to roughly 1,700 billion tons. That’s four times more than all the carbon emitted by human activity since the Industrial Revolution and twice as much as is currently present in the atmosphere.
“Soils in the north are cold,” said Ben Abbott, a UAF doctoral student at the Institute of Arctic Biology and co-author of the Nature article. “It’s like a big refrigerator, and all that material is just stored.”
With that much carbon-filled material present, a small change in the estimated amount released could make a notable difference in climate change projections. Most scientists believe gases such as carbon dioxide and methane, both of which are released by warming permafrost, contribute to global warming.
But researchers studying northern areas with permafrost have admittedly sparse data, said Ted Schuur, a University of Florida professor who co-authored the article. Because of that, he said, numerous members of the Permafrost Carbon Research Network were surveyed to collect a larger picture, combining scientific data with their predictions. A National Science Foundation grant paid for the work.
“We don’t know exactly what’s going to happen, but these are probably the best people to ask,” Schuur said.
Abbott said all the scientists in the survey felt existing models were too conservative in their projection of emissions from thawing permafrost. He said most, including him, thought the amount of carbon released would be roughly three to four times the current estimates.
The release of methane from thawing permafrost is considered an important ingredient, because it’s 25 times more potent as a greenhouse gas than carbon dioxide. Even though it represents about 2 to 3 percent of the emissions from melting permafrost, Abbott said, it could account for about half the warming.
If thawing happens at the rate the scientists believe it will, its greenhouse effect will match that of worldwide deforestation, according to the article. It still concludes, however, that fossil fuel consumption will be the biggest factor in the next century.
“It’s not likely to overshadow what’s being burned by humans, but that doesn’t mean it’s not important,” Schuur said. “It’s something that could amplify the change that’s already going on.”
Abbott said he and other researchers have more work ahead to test their hypotheses through field research. He’s spent recent summers at Toolik Field Station, a research center north of the Brooks Range, and said he’s looking forward to another season of testing soil cores and water samples for gas emissions.
Other UAF researchers who participated in the survey included Terry Chapin, IAB professor emeritus; Guido Grosse, research assistant professor at the Geophysical Institute; Dave McGuire, professor of ecology; Chien-Lu Ping, natural resources professor; Vladimir Romanovsky, Geophysical Institute professor; and Katey Walter Anthony, research assistant professor with the International Arctic Research Center.