Involving collaboration between scientists from Australia, Russia, the US, the UK, Canada and Europe the three-year study concluded that accounting for carbon stored deep in the permafrost more than doubles – to more than 1500 billion tonnes – previous estimates of the world’s high-latitude carbon inventory.
”This is equivalent to twice the current amount of CO2 in the world’s atmosphere,” says co-author, CSIRO’s Dr Pep Canadell, from The Centre for Australian Weather and Climate Research – a partnership between CSIRO the Australian Bureau of Meteorology.
“With temperatures in the higher latitudes estimated to rise by as much as eight degrees by the end of this century, the world could experience a major melt of large tracts of permafrost in Canada, Russia, Alaska, Norway, Sweden, Finland and Greenland,” he says.
“However, accurately predicting the magnitude and effect of thawing permafrost on the world’s climate is difficult for several reasons.
“While global carbon models may include simple permafrost dynamics they do not adequately represent the broader consequences, such as the decomposition of organic matter in thawing permafrost and the transformation of landscapes.”
Dr Canadell says that despite such limitations, scientists now know that even the release of a small fraction of this vast frozen reservoir of carbon would significantly accelerate climate change.
“At current rates of warming in the higher latitudes, the evidence indicates that this is likely to happen,” he says.