Chapter 11, Key Finding 3

Following the current trajectory of global and Arctic warming, 5% to 15% of the soil organic carbon stored in the northern circumpolar permafrost zone (mean 10% value equal to 146 to 160 Pg C) is considered vulnerable to release to the atmosphere by the year 2100. The potential carbon loss is likely to be up to an order of magnitude larger than the potential increase in carbon stored in plant biomass regionally under the same changing conditions (high confidence, very likely).