International climate policy must reflect the threat of permafrost thaw.
Depending on how hot we let it get, carbon emissions from Arctic permafrost thaw are expected to be in the range of 30 to more than 150 billion tons of carbon (110 to more than 550 Gt CO2) this century, with upper estimates on par with the cumulative emissions from the entire United States at its current rate. To put it another way, permafrost thaw emissions could use up between 25 and 40 percent of the remaining carbon budget that would be necessary to cap warming at the internationally agreed-upon 2 degrees Celsius global temperature threshold established in the Paris Agreement.
Potential cumulative permafrost carbon emissions (Gt CO2) by 2100 compared to some of the world’s largest fossil fuel emitting nations, if their current emissions rates continue through the end of the century. Neglecting permafrost is equivalent to excluding a major world economy from global climate policy. Data from Schuur et al. 2015, the Union of Concerned Scientists for 2019.
Of IPCC models do not include carbon emissions from permafrost thaw
Of our global carbon budget could be taken up by permafrost emissions
550 Gt CO2
Is projected to be emitted from permafrost thaw by 2100 without aggressive climate mitigation