Global Warming

Published on July 2nd, 2009 | by Ruedigar Matthes

The Point of No Return: Melting Permafrost Poses Major Threat to Climate Change

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Permafrost, or permanently frozen ground – soil, sediment or rock that remains at or below 0° Celsius for at least two continuous years – makes up about 24 percent of the exposed land mass in the Northern Hemisphere: that’s approximately 22.79 million square kilometers. Permafrost can be thousands of years old, or it can be just beginning. Either way, as permafrost thaws, it jeopardizes both man-made structures and natural features. Thawing permafrost on mountain slopes can lead to landslides.

And it’s melting.

Besides posing threats to structures and landscapes on a local scale, melting permafrost emits carbon dioxide and methane, according to the Commonwealth Scientific and Industrial Research Organisation (CSIRO), making permafrost a threat on a global scale.

“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.”

In a paper published in the most recent issue of Global Biogeochemical Cycles, Dr. Canadell informs that permafrost has the potential to release vast quantities of carbon and methane into the atmosphere, which would only add to the climate change crisis.

“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.” And as the global temperature increases, an irreversible process of thawing could be initiated.

“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.” As the permafrost thaws and melts, ‘thermokarst lakes’ form. These ‘lakes’ are bodies of freshwater, usually shallow, that are formed in depressions by melt-water from thawing permafrost. The formation of such lakes would draw heat to deeper layers and bring methane to the surface.

An increase in fire frequency could also trigger permafrost melt and thermokarst formation.

“The potential for significant feedbacks from permafrost carbon could be realised with only a small fraction of currently frozen carbon released to the atmosphere,” said Canadell. “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.”

As the global temperature rises, permafrost melts. As permafrost melts, carbon dioxide and methane are emitted into the atmosphere, causing increases in the temperature. The temperature increase spurs on permafrost thaw, etc., etc. The cycle is vicious and, as Canadell states, could be irreversible.

Are we past the point of no return? Not yet. But action must be taken now to slow or, if possible, stop the melting of permafrost.

More: What is being done to battle climate change globally and locally?

Photo Credit: Marina & Enrique via flickr under Creative Commons License


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About the Author

I'm a 22 year old student of English and Environmental Studies at the University of Utah in Salt Lake City, Utah. Born and raised in Salt Lake City, I've grown up loving the red rock of southern Utah as well as the pristine mountains of the northern fronts. Besides saving the planet one blog post at a time, I enjoy soccer, the natural world, reading and writing.



  • Peter Ridley

    This entire scare about humans causing global warming through our use of fossil fuels is UN-inspired propaganda. The UN’s IPCC has made assumptions about climate feedback effects that are not validated by the empirical evidence. It has been shown using the laws of physics that even if the atmospheric concentration of carbon dioxide was to increase to a level of 8 times that which existed in 1750 the mean global temperature would only increase by 2 degrees centigrade. That level of increase in CO2 amounts to a change of roughly 2000ppm. Anyone wishing to review the analysis upon which these conclusions are drawn should refer to http://mistakesinipcccalculations.blogspot.com/.

    Dr Canadell talks about a 10% melt of permafrost causing possibly an 80ppm increase to result in a 0.7 degree centigrade increase which is a gross exaggeration. Dr Candell would seem to have made the same mistake as did the IPCC in assuming feedbacks that do not occur in practice.

    It is totally irresponsible for the media (like this) to make unsubstantiated claims about future climate change which no-one can yet forecast reliably. Please stop this scare-mongering propaganda.

    Best regards, Pete Ridley, Human-made global climate change agnostic.

  • Brad Arnold

    By the way, in response to Nix’s comment that there was nothing anyone could do about emissions, I agree that a global carbon diet is unfeasible (the US government forecasts a 50% rise in global emissions by 2030).

    Before you despair, there is an inexpensive simple way to immediately cool down the Earth: just add a little (more) sun dimming aerosol into the upper atmosphere. The short-lived sun dimming pollution we already (inadvertently) put into the air is cooling us down around 1C.

    If this scheme backfires, it can be halted and the particles will wash out of the air. Since this scheme immediately cools the Earth, we can wait until most everyone is convinced global warming is real and very harmful before we start. An engineered aerosol (rather than sulfur dioxide like volcanoes spew) could be more than ten times more effective at dimming the sun and not hurt the ozone layer.

    “The alternative (to geoengineering) is the acceptance of a massive natural cull of humanity and a return to an Earth that freely regulates itself but in the hot state.” –Dr James Lovelock

  • Brad Arnold

    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.

    On the other hand, melting submarine permafrost is often overlooked: for instance 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

  • Nix

    Even if humans are directly responsible for climate change, the fact is, there is NO way any of us are going to change what we are doing beyond “lol, I bought new lightbulbs I’m helping the earth”.

    Especially when you consider that much of the third world wants to and is trying very hard to develop, as they should.

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