Northern Permafrost Turns Carbon Source by 2055, Driving 3-32 Pg C Loss by 2100
Updated
Updated · R&D World · Jun 18
Northern Permafrost Turns Carbon Source by 2055, Driving 3-32 Pg C Loss by 2100
1 articles · Updated · R&D World · Jun 18
Summary
A revised ORCHIDEE-MICT model projects northern permafrost will flip from a carbon sink to a carbon source around 2055 under high emissions, ending the century with a net loss of 3 to 32 petagrams of carbon versus 1900.
The shift comes after researchers added deep Yedoma and peat carbon that standard CMIP6-era frameworks largely miss, lifting estimated preindustrial northern carbon stocks to 2,028 Pg C—226 Pg C above the old model.
That added carbon is concentrated in faster-turnover pools more vulnerable to decomposition after thaw, while more than 30% of permafrost ecosystems are already net carbon sources because nonsummer emissions have been undercounted.
The study says the timeline is conservative because it excludes abrupt thaw, thermokarst lakes, wildfire interactions, methane and vegetation feedbacks, all of which could accelerate carbon release.
If permafrost stops absorbing carbon in the 2050s instead of remaining a sink through 2100, the remaining budget for limiting warming to 2C is overstated and emissions cuts would need to come faster.
With permafrost now a carbon source, what other climate 'time bombs' are yet to be factored into our warming projections?
As the Arctic's 'sleeping giant' of carbon awakens, how does this rewrite the deadlines for humanity to avert climate disaster?
Arctic Permafrost Thaw: The Overlooked Carbon Bomb Undermining Global Climate Goals
Overview
As of 2026, the Arctic is experiencing a rapid and urgent transformation, shifting from its traditional role as a net carbon sink to becoming a significant source of carbon. This change is driven by rapid climate warming, which has already caused alarming losses in permafrost coverage. If human carbon emissions are not reduced, projections show even greater permafrost loss ahead. As the permafrost thaws, large amounts of previously frozen organic carbon are released into the atmosphere, creating immediate and far-reaching consequences for global climate stability.