Methane is one of the big three greenhouse gases, next to carbon dioxide and nitrous oxide, and its concentration in the atmosphere has been increasing since the Industrial Revolution.
One way that methane gets taken out of the atmoshphere is by getting absorbed into soil. But a new study suggests this pathway isn’t quite as effective as we thought.
The study, in the Proceedings of the National Academy of Sciences, found we’re overestimating how much soil helps us out scrub the atmosphere of methane.
Here’s how it works: There are bacteria that live in soil.
“They have the ability to eat methane,” says the study’s lead author, Peter Groffman, a microbial ecologist at the City University of New York Advanced Science Research Center and senior research fellow at the Cary Institute of Ecosystem Studies. “These bacteria can extract the energy in methane and make a living.”
LISTEN: “Forest Soils are Absorbing Less Methane. Here’s Why That Matters.”
Groffman and a co-author found over the past couple of decades, soils have not been able to pull methane out of the atmosphere as well as they used to. He says our changing climate means more rain in some parts of the world.
“There’s been more rainfall over time at our research sites, and that’s making the soils wetter. And when the soils are wetter, the bacteria are less able to access the methane in the atmosphere,” he says.
He says they also looked at more than 300 other studies on methane uptake by soil.
“In places around the world where precipitation has gone up over the last 30 years or so, methane uptake is going down,” says Groffman.
And this has bigger implications for climate change.
Groffman says we rely a lot on nature to help us, but nature has limits.
“We’re going to have to work a little harder to control the sources of methane that we have an influence on,” he says.
He says that means reducing leaks from natural gas extraction and transport, and being more efficient in how we produce rice, meat and dairy products.
This story comes from our partners at Michigan Radio’s Environment Report, a program exploring the relationship between the natural world and the everyday lives of people in Michigan.