Polski
Science, In this issue, Issue 6/2026
Increased Methane Emissions from Peatlands—An Unexpected Cost of Oil and Gas Exploration
Jun
The authors of the study, whose findings were published in the scientific journal *Communications Earth & Environment*, analyzed the impact of oil and gas exploration and production activities on methane emissions from boreal peatlands in Alberta, Canada. Particular attention was paid to so-called seismic lines—narrow corridors cut through the forest for geological surveys. In Alberta alone, more than 345,000 kilometers of such routes run through peatlands.
Peatlands are among the most important ecosystems regulating the global carbon cycle. They store as much as 600 Pg (petagrams) of carbon worldwide, of which 300 to 550 Pg are found in northern peatlands. At the same time, they are a natural source of methane (CH₄), a greenhouse gas whose global warming potential over a 100-year period is about 45 times greater than that of carbon dioxide.
Why did scientists become interested in seismic lines?
To date, numerous studies have indicated that seismic lines affect vegetation, soil conditions, and animal habitats. However, much less was known about their impact on the carbon cycle and greenhouse gas emissions.
The authors hypothesized that methane emissions would be higher in areas crossed by seismic lines than in undisturbed sections of peatlands. The reasons for this were thought to be a shallower groundwater table, higher soil temperature, and changes in vegetation structure. The study was conducted in 2018–2019 at three sites: two raised bogs and one lowland bog.
Warmer and wetter due to human activity
The results showed that seismic lines significantly alter local environmental conditions. Within the study areas, the soil along the seismic lines was, on average, at least 1°C warmer than in the surrounding natural sections of the peatlands.
At the same time, at most sites, the groundwater level was closer to the surface. The authors attribute this phenomenon to the compaction of peat during the construction and use of the routes, as well as to the removal of trees that had previously drained water through transpiration.
Such conditions—higher temperatures and greater humidity—favor the processes responsible for methane production.
Changes in Vegetation Composition Following the Clearing of a Forest Strip
The laying of seismic lines also led to significant changes in vegetation composition. At most sites, a decrease in the proportion of mosses and lichens and an increase in the proportion of vascular plants were observed. The increase in ground cover by grasses (graminoids) is particularly pronounced, especially in lowland peatlands. In other locations, the proportion of shrubs also increased.
These changes had an impact on ecosystem productivity. At all sites, the ground vegetation along the seismic lines exhibited higher productivity than in adjacent undisturbed areas. The highest photosynthetic activity was recorded in the lowland peatland, whereCO2 uptake by the ground vegetation averaged 17.1 gCO2 m⁻² per day, while in the natural part of the peatland it was 6.1 gCO2 m⁻² per day.
Methane emissions increased at all sites studied
The most important finding of the study concerns the increase in methane emissions. Over the course of two growing seasons, these emissions were significantly higher along all seismic lines than in the surrounding natural peatland areas. The highest absolute values were recorded in the lowland peatland. The average methane flux there reached 93.0 mgCH₄ m⁻² per day along the seismic line, compared to 52.7 mgCH₄ m⁻² per day outside it.
In raised bogs, emissions were 18.3 and 7.0 mgCH₄ m⁻² per day, and 16.3 and 5.3 mgCH₄ m⁻² per day, respectively. It is worth noting that although raised bogs emitted less methane than fens, it was in raised bogs that the relative increase in emissions was greatest.
What had the greatest impact on methane emissions?
Statistical analysis showed that the key factor influencing methane emissions was the groundwater level. The closer the water was to the surface, the higher theCH4 emissions were.
Groundwater level alone accounted for approximately 19 percent of the observed variability in methane emissions. However, the authors found no significant correlations betweenCH₄ emissions and soil temperature, vegetation cover, or plant productivity when these factors were analyzed separately. This indicates that the hydrology of the peatland played a dominant role in controlling gas emissions.
The scale of the changes may be greater than we realize
The authors emphasize that individual seismic lines occupy a relatively small portion of the landscape (their share in the studied sites ranged from 1.1 to 5.1 percent of the peatland area), yet their impact on total emissions was noticeable. Taking into account the area occupied by the lines increased methane emissions from the entire studied peatlands by 1.6 to over 8 percent. According to the authors, the significance of this effect stems primarily from the enormous scale of such disturbances in the boreal landscape.
Researchers note that changes caused by seismic lines can persist for decades. In the case of one of the raised bogs studied, the effects of another disturbance were still visible even after 50 years.
The study’s findings provide a strong case for including these types of impacts in national emissions inventories and in the planning of measures related to the conservation and restoration of boreal peatlands.
Source:
Korsah, P., Davidson, S.J., & Strack, M. “Increased methane emissions from boreal peatlands following linear disturbances.” *Commun Earth Environ* 7, 360 (2026). https://doi.org/10.1038/s43247-026-03273-w
