At what point might we trigger a permafrost tipping point? New research from the caves of Siberia points to a threshold temperature of just 1.5 degrees celsius. At that temperature we could see large swathes of permafrost across Siberia melting resulting in the release of more than 1,000 gigatons of carbon and methane. This would be a substantial climate feedback resulting in even greater global warming. There would also be substantial damage to natural and human environments and structures.
And we are already halfway there to warming the world by 1.5C, with an estimated global temperature rise since the Nineteenth century of between 0.7 and 0.8 degrees C. There is already enough inertia in the climate system to carry us over this threshold. Which makes every attempt to reduce carbon emissions, and the use of fossil fuels, as worthwhile to limit the permafrost thaw.
Related: Methane and CO2 in thawing Arctic permafrost a climate tipping point | "We do have an emergency" - Arctic Methane Feedback amplifying warming | Arctic Permafrost thawing raising CO2 levels