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Thawing of Arctic permafrost leads to irreversible climate change

Where even the earth is melting, SMH, November 28, 2012   Ben CubbyENVIRONMENT EDITOR THE world is on the cusp of a “tipping point” into dangerous climate change, according to new data gathered by scientists measuring methane leaking from the Arctic permafrost and a report presented to the United Nations on Tuesday.

“The permafrost carbon feedback is irreversible on human time scales,” says the report, Policy Implications of Warming Permafrost. “Overall, these observations indicate that large-scale thawing of permafrost may already have started.”

While countries the size of Australia tally up their greenhouse emissions in hundreds of millions of tonnes, the Arctic’s stores are measured in tens of billions. Human-induced emissions now appear to have warmed the Arctic enough tounlock this vast carbon bank, with stark implications for international efforts to hold global warming to a safe level. Ancient
forests locked under ice tens of thousands of years ago are beginning to melt and rot, releasing vast amounts of greenhouse gases into the air.
The report estimates the greenhouse gases leaking from the thawing
Arctic will eventually add more to emissions than last year’s combined
carbon output of the US and Europe – a statistic which means present
global plans to hold climate change to an average 2degree temperature
rise this century are now likely to be much more difficult.
Until very recently permafrost was thought to have been melting too
slowly to make a meaningful difference to temperatures this century,
so it was left out of the Kyoto Protocol, and ignored by many climate
change models…….
Methane is not present in the frozen soil, but is instead created as
the earth thaws and organic matter is consumed by tiny organisms.
“If the Arctic becomes warmer and drier, we will see it released as
carbon dioxide, but if it is warmer and wetter it will be released as
methane.”
The findings of the first year of the experiment are so complex that
Professor Miller and his team at NASA’s Jet Propulsion Laboratory are
still trying to work out exactly what they have found. The results are
being kept secret, which is standard practice while the numbers are
crunched and the work is submitted to a peer-review process…….
Like Professor Miller, Mr Abbott’s job involves long expeditions into
the Alaskan tundra.
“I think it’s easy for people to feel that the Arctic is just a far
away place that will never have any direct effect on their life,” he
said. “[But] the last time a majority of permafrost carbon was thawed
and lost to the atmosphere, temperatures increased by 6degrees. That’s
a different world. Too often climate change is depicted as a story of
drowning polar bears and third world countries. Human-caused climate
change has the potential to change our way of life. Mix in the potent
feedbacks from the permafrost system and it becomes clear that we need
to act now.”
http://www.smh.com.au/environment/climate-change/where-even-the-earth-is-melting-20121127-2a5tp.html#ixzz2DXXUpw8e

November 28, 2012 - Posted by Christina Macpherson | climate change, OCEANIA, Reference