Arctic Permafrost Thaw Releasing Stored Methane
Arctic permafrost contains an estimated 1500 gigatons of organic carbon, roughly twice the amount currently in the atmosphere. Thawing is projected to release 50 to 250 gigatons of carbon by 2100, with methane emissions from the Boreal-Arctic region already increasing 9 percent since 2002. Recent 2025 research identified previously overlooked thermogenic methane sources trapped in ancient geological formations, and abrupt thaw processes could add 60 to 100 additional gigatons by 2300, amplifying warming by up to 0.5 degrees Celsius.
Probability
Horizon: 30y
By consensus
High divergence across consensus frameworks
Claims
Permafrost thaw could release 50 to 250 gigatons of carbon by 2100, contributing up to 0.5 degrees Celsius of additional warming beyond current climate model projections.
Multiple studies including NASA-funded research and Nature Climate Change publications support these estimates. The range reflects genuine uncertainty in thaw rate models and carbon stock distribution.
Permafrost thaw represents a positive feedback loop where warming releases carbon which causes more warming. Such self-reinforcing dynamics are often underestimated by linear modeling approaches.
Some 2025 studies (e.g., Sweden permafrost research) found less methane release than feared in certain regions. The range is wide, and the lower end may be more likely if drainage shifts microbial communities toward less methane production.
Abrupt permafrost thaw adds 60 to 100 gigatons of carbon beyond gradual thaw estimates, increasing carbon emissions by 125 to 190 percent compared to gradual thaw alone.
Studies on thermokarst and abrupt thaw processes published in Nature Geoscience and Nature Communications document this additional carbon release pathway that is poorly represented in standard Earth system models.
Arctic indigenous communities have documented accelerating landscape changes including thermokarst lake formation, coastal erosion, and infrastructure damage from permafrost instability well before these processes were captured in climate models.
Indicators
- • Methane emissions from Boreal-Arctic region increased 9 percent since 2002
- • Total Arctic-Boreal methane emissions estimated at 48.7 Tg CH4 per year
- • Permafrost active layer depth exceeding historical baselines across monitoring sites
- • Discovery of thermogenic methane sources from ancient geological formations in 2025
- • Abrupt thaw features (thermokarst) expanding across Arctic landscapes
- • Arctic warming at two to four times the global average rate
Interactions
Amplified by
Sources
- NASA — Unexpected future boost of methane possible from Arctic permafrost (accessed Fri Apr 03 2026 00:00:00 GMT+0000 (Coordinated Universal Time))
- The Arctic Institute — Thawing Grounds, Rising Stakes: Permafrost Emissions in Climate Policy (accessed Fri Apr 03 2026 00:00:00 GMT+0000 (Coordinated Universal Time))
- Harvard Salata Institute — Thawing permafrost: what does it mean? (accessed Fri Apr 03 2026 00:00:00 GMT+0000 (Coordinated Universal Time))
- ScienceDaily — Glacial fracking: a hidden source of Arctic greenhouse gas emissions (2025) (accessed Fri Apr 03 2026 00:00:00 GMT+0000 (Coordinated Universal Time))
- Nature Climate Change — Seasonal increase of methane emissions linked to warming in Siberian tundra (accessed Fri Apr 03 2026 00:00:00 GMT+0000 (Coordinated Universal Time))