Overview
- The peer-reviewed paper published Sept. 10, 2026 used a reduced-complexity climate model to combine four warming-induced feedbacks—permafrost thaw, wildfires, wetlands, and inland waters—and quantify their joint effect on global temperature.
- Authors report these feedbacks could add about 0.2–0.4°C of warming by 2100, which is roughly a 20–30% amplification of post-2020 human-caused warming depending on emission scenarios.
- Permafrost thaw is the single largest contributor, accounting for roughly half of the additional warming because thawing soils release stored carbon as CO2 and methane when microbes decompose ancient organic matter.
- The study warns most current Earth system models and carbon-budget calculations largely omit these natural emissions, so projections likely underestimate future warming and overestimate how much more carbon can be burned to meet targets.
- Researchers say the extra warming scales with human emissions, so rapid cuts in fossil-fuel emissions would reduce the size of these feedbacks, and they call for adding these processes to IPCC-style assessments and next-generation climate models.