By Laura Watson
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).
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?
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?
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!
OCS Media Team
The latest in climate science and policy from the OCS team.