On the Edge of Permafrost Crash
November 29, 2012
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.
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.
“Permafrost emissions could ultimately account for up to 39 per cent of total emissions,” said the report’s lead author, Kevin Schaefer, of the University of Colorado, who presented it at climate negotiations in Doha, Qatar. “This must be factored in to treaty negotiations expected to replace the Kyoto Protocol.”
The rate of melt was “deeply concerning”, said Andy Pitman, the director of Australia’s Centre of Excellence for Climate System Science, an adviser to the Climate Commission, and a lead author of the Intergovernmental Panel on Climate Change’s reports.
“It had been assumed that on the timescale of the 21st century, that the effects of methane release would be relatively small compared to other effects – that’s why it has been largely left out of the climate models,” Professor Pitman said.
“I think it’s fair to say that until recently climate scientists underrated the rate at which permafrost melt could release methane. I think we’ve been shown to be over-conservative. It’s happening faster than we had thought … This is not good news.”
The report presented to the UN said a tipping point could still be averted if the world moved to cut emissions from fossil fuels fast.