Severely burned peatlands may cut methane after rewetting

A new study finds that peatlands badly damaged by wildfire emit far less methane after rewetting than unburned or lightly burned sites. The result could make fire-affected peatlands a more practical target for restoration while easing a major climate trade-off.

Why it matters: - Peatlands hold about one-quarter of the world’s soil carbon, so how they are restored has outsized climate implications. - Rewetting usually lowers carbon dioxide emissions, but it can also trigger methane spikes that delay climate benefits. - Severely burned peatlands may offer a rare win: lower methane after rewetting and fewer land-use conflicts because fire has already reduced agricultural value.

What happened: - Researchers at Aarhus University reported in Environmental Science and Ecotechnology that severe wildfire damage changes how peatland soils behave after rewetting. - The study was published July 29, 2026. - The team ran a 90-day laboratory incubation using drained peat soils and rewetted soils that were unburned, mildly burned or severely burned. - The researchers measured carbon dioxide, methane, soil chemistry and microbial communities.

The details: - Rewetting unburned peat caused methane emissions to rise about 40-fold compared with drained soils. - Mildly burned soils emitted six times more methane than unburned rewetted soils. - Severely burned soils did not show the same methane surge. - Methane emissions from severely burned soils were statistically indistinguishable from drained controls and 91% lower than unburned rewetted soils. - Soil analysis showed severely burned peat contained more recalcitrant carbon compounds, including phenols and aromatics. - Mild fires did not substantially change carbon chemistry, but they may have released labile carbon by breaking down soil aggregates. - Severe fires also increased soil pH and electrical conductivity. - Both factors were negatively correlated with methane emissions. - The abundance of mcrA, a key methane-production gene, dropped sharply in severely burned soils. - Methanogen communities were more active in mildly burned soils. - The paper was published under DOI 10.1016/j.ese.2026.100735. - The work was funded by the European Union’s Horizon Europe programme through WET HORIZONS and by the China Scholarship Council.

Between the lines: - The study suggests wildfire can change the restoration equation, not just damage the land. - In severely burned peatlands, fire appears to leave behind soil that is harder for methane-producing microbes to use. - That means restoration planners may be able to target burned areas first, where rewetting could deliver faster climate gains and face less resistance from farmers. - The estimated emissions savings are modest at the global scale, but the feasibility argument may matter more for policy adoption.

What's next: - The researchers estimate more than 6 million hectares of peatlands burn each year worldwide. - They say 0.5 million to 0.9 million hectares of degraded burned peatland could be suitable for rewetting. - Prioritizing those areas could avoid 0.1 million to 0.8 million tonnes of carbon dioxide equivalent in methane emissions annually, using a 100-year global warming potential framework. - Further field testing would be needed to see whether the laboratory results hold in real landscapes.

The bottom line: - Severe wildfire damage may create a narrow but useful climate opportunity: rewetting peatlands that have already burned could reduce methane risk and make restoration easier to scale.