A new study led by researchers at the Georgia Institute of Technology provides insights into how peatlands respond to warming and their role in the global carbon cycle. Peatlands, which store between a third and half of all soil carbon on Earth, are important for biodiversity and climate regulation.
“Peatlands are essential carbon stores, but as temperatures warm, this carbon is in danger of being released as carbon dioxide and methane,” said Joel Kostka, Tom and Marie Patton Distinguished Professor at Georgia Tech. He emphasized the importance of understanding the ratio of these gases: “Understanding the ratio of carbon dioxide to methane is critical…because while both are greenhouse gasses, methane is significantly more potent.”
The research, published in Nature Communications, examined microbial activity in northern peatlands using advanced genetic analysis techniques known as “omics.” The study was conducted by Borja Aldeguer-Riquelme and Katherine Duchesneau under Kostka’s supervision.
Over a decade-long experiment at Oak Ridge National Laboratory’s Spruce and Peatland Responses Under Changing Environments (SPRUCE) project in Minnesota, researchers were able to artificially warm sections of wetland ecosystems. “Over the past 10 years, we’ve shown that warming in this large-scale climate experiment increases greenhouse gas production,” Kostka said. “But while warming makes the bog produce more methane, we still observe a lot more CO2 production than methane. In this paper, we take a critical step towards discovering why — and describing the mechanisms that determine which gases are released and in what amounts.”
The team found that despite conditions favoring methane production—due to limited oxygen—peatlands produced more carbon dioxide. This challenges existing assumptions about how microbes process organic matter in waterlogged environments.
By applying metagenomics, metatranscriptomics, and metabolomics to analyze soil samples from experimentally warmed chambers over several years, researchers discovered that microbial communities remained stable even as their metabolic activity increased with temperature. “Microbes can evolve and grow rapidly,” Kostka noted. “But that didn’t happen.” Instead, they observed increased greenhouse gas emissions without significant shifts in community composition.
The study suggests that microbes may be accessing ingredients like nitrate, sulfate, or metals from organic matter to facilitate respiration processes that generate more carbon dioxide instead of methane. Further research is underway to clarify these mechanisms.
Kostka also highlighted methodological challenges: “Doing this type of integrated omics research in soil systems is still incredibly difficult.” He noted difficulties with long-term sampling without damaging experimental sites and detecting subtle changes within highly diverse microbial populations.
Funding for the study came from programs within the U.S. Department of Energy’s Office of Science—including Terrestrial Ecosystem Science Program and Genomic Science programs—as well as support from the Environmental Molecular Sciences Laboratory.
The full article can be accessed via Nature Communications at https://doi.org/10.1038/s41467-025-61664-7
