Legacy Emissions of Permafrost from Overshoot of the Paris Goal

Nature Communications, May 11

Carbon emissions from thawed permafrost are known to continue for 150-200 years after initial thaw, even with refreezing; but this modeling study found that permafrost ecosystems and “legacy” emissions may not stabilize for several hundred years after carbon neutrality is reached. The study found that the long-term effects of overshoot on permafrost are determined not only by how much the Earth warms (the degree of overshoot of Paris goals), but by single extreme warming events or heatwaves in a single year; as well as highly localized conditions. This means that the extent of permafrost contributions to CO2 and methane emissions may be very much underestimated in current Earth system models, especially due to such extremely long-term legacy impacts of overshoot.

https://www.nature.com/articles/s41467-021-23010-5