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Thawing Permafrost Could Emit Massive Amounts of Greenhouse Gases
While politicians around the world debate how to reduce human-caused greenhouse gas emissions, scientists are making some unsettling discoveries about another developing greenhouse gas problem: nature’s own emissions.
A study published this week shows that the amount of carbon locked in the Arctic permafrost is more than double previous estimates. Additionally, other research shows that the permafrost is thawing, meaning this enormous amount of carbon could be released into the atmosphere as the greenhouse gases carbon dioxide and methane.
The thawing of the permafrost is especially dangerous because it could cause a domino effect of more warming that, for now, cannot be checked by human engineering or policy.
"We now estimate the deposits contain over 1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere", said Dr. Charles Tarnocai, Agriculture and Agri-Food Canada, Ottawa, and lead author of the study, published in Global Biogeochemical Cycles.
As long as permafrost is frozen, the carbon in the soil is locked up.
But when it thaws, the carbon becomes exposed, and microbes called methanogens break down the carbon and release methane, a greenhouse gas that is 20 times more effective at trapping heat than carbon dioxide.
“A little bit of methane goes a long way with respect to warming,” says Breck Bowden, a University of Vermont professor conducting research in Alaska on the effects of thawing permafrost on ecosystems.
The release of methane could create a domino effect, explains Vladimir Romanovksy, professor in geophysics at the University of Alaska Fairbanks.
The thawing of the permafrost produces methane, which causes further warming, which in turn thaws more permafrost, producing more methane. 
This cycle, known as a positive feedback system, mirrors a similar feedback loop in the Arctic involving ice. Ice normally reflects the sun’s light and heat, but global warming has caused ice to melt, leaving more of the darker Arctic land and water open to absorb the sun’s heat, leading to more polar ice loss.
It’s possible that, once started, one or both of these feedback systems could continue by themselves – even if human greenhouse gas emissions were to be significantly reduced or eliminated, Romanovsky says. Alone, the permafrost could contribute to the atmosphere an amount of greenhouse gases comparable to the amount humans have emitted, and possibly more.
Bowden emphasizes that both the Arctic and global climate are complex systems whose future behavior is difficult to predict, and he cautions that scientists do not know how much carbon dioxide and methane might be produced and precisely what feedbacks will result. However, he also warns,
“It’s hard to envision how the [positive feedback] scenario could be stopped, though in time it might be slowed or muted by reducing [human] greenhouse gas emissions.”
At the moment, the only way to prevent this cycle is to prevent global warming and stop greenhouse gas emissions, Bowden says:
“For us to consider keeping permafrost throughout the Arctic from thawing as a consequence of global warming is beyond possible. The solutions and the technologies we have to engineer permafrost to keep it from thawing simply are way too expensive to consider employing across the Arctic. The only solution is for the Arctic to stay cold – and that won’t occur unless we stop greenhouse gas emissions.”
Romanovsky agrees:
“The only way to prevent thawing of the permafrost is to prevent warming of the climate.”
How the thawing of the permafrost will influence climate change remains to be seen, but evidence shows that the permafrost has been getting warmer over the past several decades.
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Melting submarine permafrost emissions an even bigger threat!
Thirty percent of the Earth's surface is land. Twenty percent of the land is permafrost. There is over a trillion tons of carbon frozen and buried in the land permafrost. More than half the land covered by the topmost layer of permafrost will probably thaw by 2050, so the melting of that permafrost is a gigantic threat.
But usually not included in the threat assessment is melting submarine permafrost. For instance, there is an area six times the size of Germany containing about 540 billion tons of carbon off the coast of Siberia. That submarine permafrost is perilously close to thawing. Three to 12 kilometers from the coast the sea sediment is just below freezing. The permafrost has grown porous, there is a loss of rigor in the frozen sea floor, and the surrounding seawater is highly oversaturated with solute methane.
"...Researchers were investigating "alarming" reports in the last few days of the release of methane from long frozen Arctic waters, possibly from the warming of the sea…" --"Arctic sea ice drops to 2nd lowest level on record," AP, 27 Aug '08
"If the Siberian (submarine) permafrost-seal thaws completely and all the stored gas escapes, the methane content of the planet's atmosphere would increase twelve fold. The result would be catastrophic global warming." --"A Storehouse of Greenhouse Gases Is Opening in Siberia," Spiegel, 17 April '08
thanks for this summar, a wealth of info
thanks for this summary which has overall much more info than the reuters, but oen key part in the Reuters story not mentioned here:
"He said if only 10 per cent of the permafrost melted, this could lead to the release of an additional 80 parts per million of carbon dioxide equivalent into the atmosphere."
(and that this would cause an [ADDITIONAL] 0.7C [or about 1.25F] degrees of warming from that alone)
http://www.reuters.com/article/africaCrisis/idUSSP458218
125,000 years BP (before permafrost)
As usual, history gives the lie to the hysterical claims:
October 7, 1998 Ancient Clues from a Frozen Forest Article #1409 http://www.gi.alaska.edu/ScienceForum/ASF14/1409.html
by Ned Rozell
Troy L. Péwé once discovered an interesting patch of woods near Ester, about
nine miles east of Fairbanks. The spruce and birch trees of this forest were
underground, sandwiched between layers of earth. Each tree was 125,000 years
old. Péwé, with the geology department at the University of Alaska Fairbanks from
1953 to 1965 and now with the department of geology at Arizona State University,
found the forest when he worked for the U.S. Geological Survey in 1949.
Because the trees were buried about 45 feet below the present-day forest at Eva
Creek, Péwé knew they were old. How old he didn't find out until 50 years later,
after methods of finding the age of extremely old things had been developed.
Because pencil-thin layers of volcanic ash line the soil above and below the frozen forest, Péwé and others were able to get a rough estimate of the trees' age. Péwé said the frozen forest at Eva Creek thrived at a time that was up to 5 degrees Celsius warmer than it is today, when there was little-to-no permafrost.
Because the frozen forest is full of charred trees, Péwé suspects there were a
lot of forest fires 125,000 years ago. Insect galleries carved into the bark of
some of the frozen spruce indicate that the spruce bark beetle was also here
then.
What preserved the Eva Creek frozen forest? During a cooling period, about
120,000 years ago, the Eva Creek trees died and were eventually covered with
loess from dust storms that began on the Tanana Flats. The fine, powdery soil,
the consistency of flour, was originally part of mountains in the Alaska Range
before it was pulverized by the weight and force of glaciers and carried with
melt water to the Tanana River.
In an incredibly gradual process, loess coated the Eva Creek forest. The ancient
trees froze as the climate became cold enough to produce permafrost.
Nothing new under the sun.......
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