Not so Perma-frost? Climate Change and its impact on permafrost

By Laura Watson

Source:USGS

Permafrost is a key carbon sink - it stores frozen methane. Worryingly, it is thawing much more rapidly than scientists ever predicted. This means that carbon dioxide and methane that has been locked in this permafrost for millennia, is being released into the atmosphere at a much faster rate than previously thought. This is increasing the pace of climate change – just when we are trying to curb greenhouse gas emissions.
 
The impact is drastic. To put it simply: with every 1oC rise in average global temperature, permafrost may release the equivalent of four to six years’ worth of coal, oil, and natural gas emissions. To avert a climate crisis we need to act much faster than we previously thought.
 
So what exactly is permafrost?
It is defined as ground (soil, rock or organic material) which remains at or below 0°C (so frozen) for at least two consecutive years. This can be found on the ground, or below the sea – essentially in any areas where temperatures rarely rise above freezing. Permafrost can show huge variations across the planet – it can vary in thickness and can be continuous or discontinuous (with continuous being a single sheet, and discontinuous permafrost broken up into areas for example in the shadow of a mountain).
 
The problem
With slow and steady permafrost melt, 200 billion tonnes of carbon would be released to the atmosphere over the next 300 years. However, this may be a vast underestimate as around 20% of permafrost land is more prone to melt for reasons listed below.
 
Why is the permafrost melting faster than expected?

1. Unexpectedly high rate of Arctic temperature warming-the Arctic is warming faster than any other area on the planet. Whereas the global average temperature has increased by 0.8°C since the late 19th century, the Arctic has warmed by a staggering 3°C in that same time period.
2. The movement of glacial melt-water through the Arctic is causing the formation of denser ice sheets, which further increases permafrost melting.
3. Positive feedback loops- frozen soil holds the ground together. This means that as the pockets of ice within the permafrost melt, the permafrost collapses rapidly causing the land to sink and become inundated with water. This accelerates melting, creating a positive feedback as the inundations spread beyond the melted ice pocket to form lakes and wetlands which causes further melting.

 
What does the melting of Permafrost mean for 1.5oC targets?
There is uncertainty as to whether we will reach 1.5oC warming by 2030 – or sooner – as we are unsure how far we really have risen above pre-industrial temperatures.  We are operating with rough estimates because monitoring technology is a relatively recent development and calculating averages for today's temperature is not entirely accurate either.
 
Whether or not we have until 2030 to avert climate catastrophe remains unclear. What we can be  certain of, is that unforeseen impacts from tipping points such as the melting of the permafrost, could alter these rates.
 
What can we do to manage the melting?

• Extend the measurement technology
• Increase funding to monitoring sites
• Gather more data
• Build holistic models
• Improve reports to show the impacts of abrupt thawing

 
Overall, while research into melting permafrost is new and unexpected, it is being measured so mitigation steps can be taken to ensure that a tipping point isn’t reached  and to avert a climate catastrophe.

​What is clearer than ever is the need for rapid action!
 
 
References
https://www.nationalgeographic.com/environment/2019/08/arctic-permafrost-is-thawing-it-could-speed-up-climate-change-feature/
 
https://www.nationalgeographic.org/encyclopedia/permafrost/
 
https://ipa.arcticportal.org/publications/occasional-publications/what-is-permafrost
 
https://advances.sciencemag.org/content/5/12/eaaw9883
 
https://www.nationalgeographic.com/environment/2019/09/greenland-ice-getting-denser-thats-bad/
 
https://www.nature.com/articles/d41586-019-01313-4
 
https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_SPM_version_report_LR.pdf
 
http://cowles.yale.edu/sites/default/files/files/pub/d04/d0443.pdf
 
https://theconversation.com/why-protesters-should-be-wary-of-12-years-to-climate-breakdown-rhetoric-115489