New research shows that the amount of carbon stored in frozen soils at high latitudes is double previous estimates and could, if emitted as carbon dioxide and methane, lead to a significant increase in global temperatures by the end of this century. The increased temperatures and permafrost melt could trigger the release of thousands of years of animal waste and other organic matter left behind on the Arctic tundra that have been sealed off from the environment by permafrost. Climate change is melting the permafrost and freeing mass quantities of prehistoric "ooze" from its state of suspended animation.
"Massive amounts of carbon stored in frozen soils at high latitudes are increasingly vulnerable to exposure to the atmosphere," says the Executive Director of the Global Carbon Project at CSIRO, Dr Pep Canadell.
"The research shows that the amount of carbon stored in soils surrounding the North Pole has been hugely underestimated. "Using the new carbon pool estimates from this research, permafrost degradation could account for the entire upper range of carbon-climate feedbacks currently estimated by climate models," Dr Canadell says.
"Warmer temperatures at high latitudes are already resulting in unprecedented permafrost degradation," he says. "Projections show that almost all near-surface permafrost will disappear by the end of this century exposing large carbon stores to decomposition and release of greenhouse gases."
"A number of feedbacks increase the vulnerability of these soils. For example, heat generated from increased microbial activity could lead to sustained and long-term chronic emissions of carbon dioxide and methane." In addition, 'thermokast lakes' formed as permafrost thaws, would draw heat to deeper layers and bring methane to the surface.
"The potential for significant feedbacks from permafrost carbon could be realised with only a small fraction of currently frozen carbon released to the atmosphere. For example if only 10 per cent of the permafrost melts, the resultant feedback could result in an additional 80 ppm carbon dioxide equivalent released into the atmosphere, equating to about 0.7°C of global warming."
Russian scientist, Sergei Zimov, who has been studying climate change in Russia’s Arctic for 30 years, is worried that as organic matter becomes exposed to the air it will drastically accelerate global warming predictions even beyond some of the most pessimistic forecasts.
“This will lead to a type of global warming which will be impossible to stop,” he said.
According to Zimov, when the organic matter left behind by mammoths and other wildlife is exposed to the air by the thawing permafrost, microbes that have been dormant for thousands of years will spring back into action. They'll begin once again to emit carbon dioxide and methane gas as a by-product. Zimov says thought the microbes are tiny, they will start emitting these gases in enormous quantities simply because there will be a lot of them.
Yakutia is a region in the north-eastern corner of Siberia, where a belt of permafrost contains the mammoth-era soil. It covers an area roughly the size of France and Germany combined. There is even more of it elsewhere in Siberia.
“The deposits of organic matter in these soils are so gigantic that they dwarf global oil reserves,” Zimov said. U.S. government statistics show mankind emits about 7 billion tons of carbon a year.”Permafrost areas hold 500 billion tons of carbon, which can fast turn into greenhouse gases,” Zimov added. “If you don’t stop emissions of greenhouse gases into the atmosphere … the Kyoto Protocol (an international pact aimed at reducing greenhouse emissions) will seem like childish prattle.”
While some dismiss the 52-year-old as an alarmist crank, his theory is steadily gaining credibility in the scientific community. “There’s quite a bit of truth in it,” Julian Murton, member of the International Permafrost Association, told Reuters. “The methane and carbon dioxide levels will increase as a result of permafrost degradation.”
Permafrost stores a lot of carbon, with upper permafrost layers estimated to contain more organic carbon than is currently contained in the atmosphere. Permafrost thawing results in the release of this carbon in the form of greenhouse gases which will have a positive feedback effect to global warming.”
Posted by Casey Kazan with Rebecca Sato
The Centre for Australian Weather and Climate Research (CAWCR) [external link]
The Centre for Australian Weather and Climate Research is a partnership between CSIRO and the Bureau of Meteorology.
http://www.csiro.au/news/Permafrost-climate-change-threat.html
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