Thawing Arctic Permafrost – A new source of greenhouse gas emissions


As climate change leads the planet to a warmer climate, frozen soils within Arctic and sub-Arctic regions have started to thaw, releasing greenhouse gases in the form of carbon dioxide and methane from the large amounts of organic carbon stored in permafrost. 70 percent of permafrost is expected to decline within the next century, so this environmental feedback can accelerate the greenhouse effect in an uncertain way.

In 2009, Philippe Ciais, a researcher from the Laboratory for Climate Sciences and the Environment in Gif-sur-Yvette, France, highlighted in the Copenhagen Climate Congress the catastrophic consequences climate change has on Arctic permafrost. Not only did he focus on the rise of sea levels and the risk of coastal areas disappearing under water, but he emphasized that the result from the melting frozen Arctic soil will prove to accelerate the greenhouse effect. Even a 2oC average temperature rise can induce thawing of permafrost and release billions of tons of carbon dioxide and methane.

However, according to a new overview that has just been published in Nature by an international team of 17 scientists led by Edward Schuur of Northern Arizona University, this new source of greenhouse gas emissions is more than a slow burning bomb. A. David McGuire, co-author and U.S. Geological Survey senior scientist and climate modeling expert with the Institute of Arctic Biology at the University of Alaska Fairbanks, explains that past evidence shows a gradual and prolonged way of releasing permafrost carbon.

After an in-depth study of past estimates, the team has concluded that there are between 1330 and 1580 gigatons of carbon in the top three meters of global permafrost soil -yedomas (permafrost with particularly high ice content), and in Arctic river deltas. With the potential of 400 additional gigatons in “deep terrestrial permafrost sediments” and and unknown amount in permafrost below the sea in shallow continental shelves, we come to the conclusion that there is a troublingly large amount of carbon we have to deal with. Based on these numbers, the UN Intergovernmental Panel on Climate Change suggests that we should move towards a target of about 500 gigatons of carbon emissions in order to fulfill the goal of keeping global warming to 2 degrees Celsius.

According to measurements, during the last thirty years there has been a temperature rise of 0.6 o C per decade in high-latitude regions of the Earth – twice as fast as the global average. The average temperature of permafrost in Alaska, Russia, and other Arctic regions has risen from 18 F to 28 F. So, as the climate gets warmer and permafrost melts, the released carbon dioxide and methane into the atmosphere can create additional warming .Thus, it is important the scientific community and world leaders take into account permafrost carbon releases in order to achieve our goal to hold global warming by cutting down on emissions.

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About the author

Irini Chassioti is a teacher and chemist with a master’s degree in Environmental Chemistry and Technology. She was born and raised in the northern suburbs of Athens and is an active member of the local city improvement association. Her activities include the protection of the local ecosystem, writing scientific articles related to environment, ecology and sustainable development and the education of pupils on environmental issues.