Severe peatland fires could make rewetting much cleaner for the climate

A new study from Aarhus University finds that rewetted peatlands hit hard by wildfire emit far less methane than unburned or lightly burned sites. The results suggest fire-damaged peatlands could be a better bet for large-scale restoration because they may deliver climate gains faster and face less opposition from farmers.

Why it matters: - Peatlands store about one-quarter of global soil carbon, so what happens to them has outsized climate impact. - Rewetting drained peatlands can cut carbon dioxide emissions, but it often raises methane, which can delay net climate benefits. - Severe wildfire damage may flip that trade-off and make some degraded peatlands stronger candidates for restoration.

What happened: - Researchers at Aarhus University tested how wildfire history changed greenhouse gas emissions after rewetting peat soils. - The study appeared in Environmental Science and Ecotechnology and was published July 29, 2026. - The team ran a 90-day lab incubation on drained peat soils and rewetted soils that were unburned, mildly burned or severely burned. - The researchers measured carbon dioxide and methane, studied soil chemistry and examined microbial communities. - The article includes a DOI link for the paper: the published study.

The details: - Rewetting unburned peat caused about a 40-fold jump in methane emissions versus drained soils. - Mildly burned soils emitted even more methane, with levels six times higher than rewetted unburned soils. - Severely burned soils behaved differently, with methane emissions staying low and statistically similar to drained controls. - That amounted to a 91% reduction in methane compared with rewetted unburned soils. - Fourier-transform infrared spectroscopy showed severely burned soils had more recalcitrant carbon compounds, including phenols and aromatics. - Mild fires did not substantially change carbon chemistry, but may have released labile carbon by breaking down soil aggregates. - Severe fires also raised soil pH and electrical conductivity, and both were linked to lower methane emissions. - The abundance of mcrA, a key methane-production gene, fell sharply in severely burned soils. - Methanogen communities were more active in mildly burned soils. - The authors said severe fires can override the usual methane spike expected after rewetting because heat changes the peat and slows microbial recovery.

Between the lines: - The finding suggests wildfire damage can create a narrow restoration window where a climate liability becomes a climate advantage. - Burned peatlands often lose agricultural value, which may reduce land-use conflict and make rewetting easier to scale. - The science does not make wildfire desirable, but it does point to an unexpected way to prioritize restoration where it may be most feasible.

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 that area could be degraded peatlands suitable for rewetting. - Prioritizing those fire-affected areas could avoid 0.1 million to 0.8 million tonnes of carbon dioxide equivalent in methane emissions each year under a 100-year global warming potential framework. - Further restoration planning will likely focus on identifying where severe fire damage, degraded land and rewetting potential overlap.

The bottom line: - Severely burned peatlands may be among the best places to rewet first because they can cut methane more sharply and face fewer social barriers than productive farmland.