Earth's methane levels began to spike in 2020; a new study may have uncovered the 'culprit.'

Wetlands and cow stomachs have similar
environments. (Adobe Stock photo)

In 2020, Earth's methane levels started to climb the charts at an inexplicable rate, putting the planet on a crash course with greenhouse gases that could eventually heat oceans and land to life-threatening temperatures, reports Shannon Osaka of The Washington Post. Researchers have been baffled by the cause -- until now. Scientists say a study released last month reveals why methane levels are spiking.

"The culprits, scientists believe, are microbes — the tiny organisms that live in cows’ stomachs, agricultural fields and wetlands," Osaka writes. "That could mean a dangerous feedback loop — in which these emissions cause warming that releases even more greenhouse gases — is already underway."

Sylvia Michel, lead author of the paper published in the Proceedings of the National Academy of Sciences, told Osaka, "The changes that we saw in the last couple of years — and even since 2007 — are microbial." Oska adds. "The new paper points to microbes as the biggest source of the methane spike."

In clarifying the source of rising methane levels, the study ruled out fossil fuels and geological causes. Stanford University professor Rob Jackson, who is part of the Global Methane Budget, explained how cow stomachs and swampy places are alike. He told Osaka, "Methane forms biologically in warm, wet, low-oxygen environments. The wetlands of a rice paddy and the gut of the cow are all similar.”

Microbe methane output may be a chemical reaction to a warming planet. Osaka reports, "Michel says it’s too early to say whether this is the beginning of a vicious cycle. 'Are these coming from human-caused changes in freshwater systems, or are they a kind of scary climate feedback?' she said. 'I want to be careful about what we can and cannot say with this data.'"