How beavers help slow climate change – a new discovery by scientists

Even children know that beavers are masters of natural water retention. European scientists have recently shown that these industrious rodents also do the Earth another favor by storing huge amounts of carbon in their wetlands. It is high time to definitively abandon the stereotype of a pest and restore the beaver’s reputation.

The beaver as a climate engineer

The study, the results of which were published on March 18 this year in the journal Communications Earth & Environment, is the result of cooperation between scientists from the University of Birmingham, Wageningen University and the University of Bern. The international research team analyzed the engineering efforts of beavers that have inhabited a stream channel in northern Switzerland for over a decade. It turned out that the wetlands created by the rodents accumulated 1,194 tonnes of carbon over 13 years.

Converting these results into unit values, the scientists estimated the carbon dioxide sequestration rate of beaver activity at 10.1 tonnes of CO2/ha/year. This means that wetland areas inhabited by beaver families store carbon at a rate 10 times faster than similar ecosystems without dams and lodges.

Dr Joshua Larsen, the lead author of the study, explains that beavers slow down water flow with their dams, trapping sediments and expanding wetlands, thereby turning streams into powerful carbon sinks. The sediments examined by the scientists contained 14 times more inorganic carbon and 8 times more organic carbon than the surrounding forest soils.

Trees fall, the climate benefits

The presence of beavers in the upper reaches of rivers turns out to radically change the carbon cycle in a given area. Dams built on small streams effectively trap large amounts of organic and inorganic matter in the form of sediments, vegetation and dead wood. Thus, according to the authors of the study, river corridors become persistent carbon stores. They will retain carbon as long as the dams remain undisturbed.

Although the level of net carbon uptake fluctuates seasonally (when water levels drop, emissions exceed sequestration), in the long term beaver wetlands prove to be an exceptionally effective CO2 sink. If beavers were introduced to all floodplain areas in Switzerland suitable for their habitation, the resulting wetlands could offset up to 1.8 percent of the country’s annual carbon dioxide emissions, providing clear climate benefits without active human intervention and without financial costs.

This highlights the enormous potential of beaver-driven river restoration and offers valuable insights for spatial planning, renaturalization strategies and climate policy, concludes Dr Lukas Hallberg from the University of Birmingham.

And what about Polish beavers?

Dr Andrzej Czech from Jagiellonian University provided a brief summary of the decarbonization potential of Polish beavers on his Facebook profile. By multiplying 30,000 hectares of domestic beaver wetlands by the sequestration rate calculated by Swiss researchers, he obtained a result of 303,000 tonnes of carbon per year. This means that Polish engineers of aquatic ecosystems are capable of capturing more than 1.1 million tonnes of CO2 within 12 months – three times more than the world’s largest direct air carbon capture installation.

If we wanted to replace Polish beavers with human technology, it would cost between 444 million and 1.1 billion dollars annually. Meanwhile, as Dr Czech points out, the animals work without electricity, without subsidies and without interruption.

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Source:

Hallberg, L., Larsen, A., Ceperley, N. et al. Beavers can convert stream corridors to persistent carbon sinks. Commun Earth Environ 7, 227 (2026). https://doi.org/10.1038/s43247-026-03283-8