In Arctic soils, methane-eating microbes could outcompete methane producers

In the Arctic, an important variable for future climate change lives in the soil, invisibly.

Microbes in the soil layers just above the frozen permafrost metabolize carbon, converting it into carbon dioxide and methane, a much more potent greenhouse gas. As these soils warm, more carbon is released, potentially setting in motion a warming feedback loop sometimes nicknamed “the”methane bomb.Now, new research on the microbial inhabitants of Arctic soils indicates that this vicious cycle may not be inevitable.

By cataloging the types of microbes found in permafrost soils across the Arctic, as well as in recently thawed permafrost itself, a group of researchers provided a clearer picture of the microbial diversity in Arctic soils, as well as how those microbial communities change as their environment warms. A key finding in your rolerecently published in Earth and Environment Communicationsis that under certain conditions there could be more methane-consuming microbes than methane-producing microbes in the Arctic, meaning the soil could end up being a carbon sink.

“It could be that these systems, for various reasons, are not actually producing the methane that we think they are capable of producing,” he said. Jessica Buser-youngmicrobiologist at the University of Alaska Anchorage not affiliated with research.

Microbes and methane

Since 2010, a consortium of scientists from Europe has been collecting samples of permafrost in the Arctic, digging into the top layer and subsoil and into the permanently frozen soil below. Collecting these samples is difficult in the vast, remote, icy northern reaches of the world, but the group recovered samples from across Canada, Greenland, and Siberia.

In the new paper, the researchers performed genomic analyzes of the microbiome of eight pan-Arctic soil and permafrost samples, as well as samples of intact and degraded permafrost near Fairbanks, Alaska. They focused specifically on microbes, comprising both bacteria and archaea, that release or consume methane, a greenhouse gas that can be 30 times more potent than carbon dioxide.

When researchers looked at the data, the first surprise came from the lack of diversity between methane-producing microbes, or methanogens, and methane-consuming microbes, or methanotrophs, said the study’s co-author. Tim Urichmicrobiologist at the University of Greifswald in Germany.

Among the methanotrophs, a single genus, methylobacterdominated the samples at all locations. These bacteria are found throughout the Arctic and often live in soil layers just above their methanogenic counterparts, consuming methane bubbling up from below. It’s not yet known why this genre has been so successful, Urich said.

The analysis “really requires studying representatives of this specific clade in more detail to understand the ecophysiology and their response to changing soil conditions,” Urich said.

Possibly deactivate the methane bomb

Urich and his co-authors also looked at sites where permafrost had thawed, comparing wet and dry places. The site with soggy soils contained more methanogenic microbes, which thrived in oxygen-starved conditions. In dry sites, by contrast, methanotrophic microbes won, especially a variety with the unique ability to take methane from the air and convert it into less potent carbon dioxide. While these facultative methanotrophs have the ability to metabolize atmospheric methane, the researchers noted, they do not necessarily do so in practice.

Still, Urich said, the upshot is that a warmer, drier Arctic may be a boon for the changing climate.

“It really depends on the hydrological fate of these soils,” he said.

If the Arctic ends up on the dry end of the spectrum, its soils could become a net methane sink (although not a very large one) as microbes begin sucking gas out of the air. The mechanism described by Urich and his colleagues is also not the only possible negative feedback loop for methane. in a recent article in AGU AdvancesBuser-Young and her co-authors found that microbes in Alaska’s Copper River Delta that use iron for their metabolism have begun to outcompete those that produce methane, potentially reducing methane emissions.

“We think this could potentially be happening everywhere in the world where there are glaciers,” Buser-Young said.

What studies like Urich’s are making clear is that while thawing Arctic permafrost is an obvious sign of climate change, its contribution to warming is less obvious, he said. Christian Knoblauchbiogeochemist at the University of Hamburg who was not involved in the research.

“We had so many articles about this methane pump” he said. “I think this was an oversimplification or overestimation of the methane release.”

The future of methane is still uncertain

Researchers are still hampered by a dearth of data on changes in the Arctic.

At the top of Urich’s list of potentially valuable data sets are studies on the ecophysiology of the methane-associated microbes he and his colleagues found in Arctic soils. Such studies would provide more data on how the metabolism of microbes changes in response to increasing temperatures and different oxygen levels, among other things.

Urich also cautioned that his research did not measure levels of methane release or uptake from Arctic soils, leaving unanswered the question of the actual impact of microbes on the environment.

Knoblauch reiterated the need for more data and noted that we cannot yet say with certainty whether the future Arctic will be wetter or drier and, therefore, what methane release will be like.

“We have a lot of models and a lot of simulations, but we don’t have as much data on the ground,” he said. “I think the big questions are really how quickly the material decomposes, how much it will thaw and to what extent [what] when it decomposes and then is released, and how the system will be affected by changing vegetation.”

—Nathaniel Scharping (@nathanielscharp), scientific writer

Citation: Scharping, N. (2025), In Arctic soils, methane-feeding microbes could outcompete methane producers, Éos, 106, https://doi.org/10.1029/2025EO250400. Published on October 31, 2025.

Text © 2025. The authors. CC BY-NC-ND 3.0
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