The predictive model developed by a European research group is based on an extensive field experiment and various IPCC climate scenarios.
The model of the study, published in the journal Nature Climate Change, is the first to assess the ability of peatlands to offset carbon dioxide emissions globally in the future. This result sheds light on the so far poorly known part of the Earth's carbon cycle and how it is altered by climate change. From Finland, Professor Eeva-Stiina Tuittila was involved in the study, and field experiment was partly carried out at Siikaneva in Ruovesi. The other researchers in the European team were from France, Poland, Estonia and Sweden.
Although peatlands make up only three per cent of the Earth's surface, more than 30 per cent of soil carbon is stored in their peat. This reservoir is estimated to represent between 500 and 1000 gigatons of carbon, which is equivalent to 56 to 112 percent of atmospheric carbon. A large part of the microbes in peatlands are decomposers that release carbon from peat into the atmosphere through their respiration. However, also microalgae live in peatlands and they are capable to bind atmospheric carbon in their photosynthesis. The increase in temperature accelerates the photosynthesis of these microbes, which strengthens the carbon sink of peatlands.
Due to a lack of information, these mechanisms have so far not been included in climate projections. According to the study, this microbial photosynthesis of peatlands is by no means insignificant, but it could mitigate the effects of climate change in the future. However, preserving the carbon storage of peatlands in their natural state and reducing carbon dioxide emissions produced by humans are still the best solution for mitigating climate change.
For further information, please contact:
Professor Eeva-Stiina Tuittila, University of Eastern Finland, tel.+358 50 442 42 99, eeva-stiina.tuittila@uef.fi
Article:
Microbial photosynthesis mitigates carbon loss from northern peatlands under warming. Samuel Hamard, Sophie Planchenault, Romain Walcker, Anna Sytiuk, Marie Le Geay, Martin Küttim, Ellen Dorrepaal, Mariusz Lamentowicz, Owen Petchey, Bjorn Robroek, Eeva-Stiina Tuittila, Maialen Barret, Régis Céréghino, Frédéric Delarue, Jessica Ferriol, Tristan Lafont Rapnouil, Joséphine Leflaive, Gaël Le Roux, Vincent E.J. Jassey. Nature Climate Change. DOI: 10.1038/s41558-025-02271-8. https://www.nature.com/articles/s41558-025-02271-8
