In the early 2020s, the mood changed as societies around the world shut down to protect people from the coronavirus pandemic. unusually large meth surge. Atmospheric scientists took notice. With everyone avoiding travel and staying at home, “we expected that anthropogenic methane emissions would decrease a little,” Peking University said. pen shushi Say. So why have powerful greenhouse gases soared rather than decreased?

To find the answer, Peng and a team of 41 scientists came together to global methane budgetIt measures the amount of methane released and removed from the atmosphere from 2019 to 2023. Drawing on its diverse expertise, the group was able to propose the main causes of the 2020-2021 methane surge: The self-purifying action of the atmosphere was temporarily blocked. (science 2026, DOI: 10.1126/science.adx8262).

“They threw the kitchen sink at it,” he says. Francesca HopkinsHe is a climate change scientist at the University of California, Riverside, but was not involved in the study.

The researchers prepared three independent computational models using a wealth of surface measurements from National Oceanic and Atmospheric Administration (NOAA) observatories across the United States and space-based observations from the GOSAT satellite. The model reveals that when fewer people drive internal combustion engines due to the coronavirus, nitrogen oxide (NO) emissions decrease._×) has fallen. This reduction inadvertently reduced the amount of methane removed from the atmosphere.

no_× Reacts with air to produce hydroxyl radicals. These destroy methane and turn it into carbon dioxide, a less potent greenhouse gas. Therefore, there will be less NO._× Inadvertence has increased the amount of methane remaining in the atmosphere.

At the same time, the model shows that wetlands in tropical Africa and Southeast Asia are emitting more methane due to three consecutive years of La Niña weather, Professor Penn says. It was the perfect formula for the spike in methane in the atmosphere.

“I appreciate that they consider chemistry and chemical models,” he says of the atmosphere. benjamin gobertHe is an atmospheric chemist at NSF’s National Center for Atmospheric Research, but was not involved in the study. Using more complex atmospheric chemistry models to figure out what’s happening within the methane budget will help future research, Gaubert says. “It’s interesting and I think it will spark some discussion,” he added.

“This paper highlights the success of all these multi-layered techniques that we have developed as a community,” says Hopkins. And it shows how difficult it is to fight climate change. Based on these results, reducing fossil fuel emissions may actually “promote warming on the methane side through OH radical chemistry,” Hopkins says. Still, reducing combustion emissions remains important to curb climate change and improve air quality, she says.

Hopkins also points to the importance of NOAA’s atmospheric measurement network in international collaborations. “The United States is not the only country that relies on these datasets,” she says. “The entire planet depends on these datasets.”