Pandemic Lockdowns Supercharged Methane Levels, Study Finds

Cleaner air from reduced emissions weakened the atmosphere's ability to scrub away the potent greenhouse gas.

Published on Feb. 9, 2026

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A new study published in the journal Science found that pandemic lockdowns and reduced emissions of nitrogen oxides led to a drop in hydroxyl radicals, which normally destroy methane before it can accumulate in the atmosphere. This weakening of the atmosphere's methane-scrubbing ability, combined with increased methane production from expanded wetlands during consecutive La Niña years, resulted in the largest recorded surge in atmospheric methane levels.

Why it matters

The findings present a challenge for policymakers, as reducing air pollution is essential for public health but may inadvertently accelerate methane accumulation and climate change. Experts say further reductions in anthropogenic emissions are needed to address this issue.

The details

The study, led by researchers at Peking University, found that reductions in hydroxyl radicals during the COVID-19 period from 2020 to 2021, followed by a recovery through 2023, accounted for roughly 80 percent of the interannual variations in methane's growth rate. With fewer hydroxyl radicals available, methane persisted longer in the air. This coincided with three consecutive La Niña years that brought heavy precipitation to tropical regions, causing wetlands in equatorial Asia and Africa to expand significantly and produce more methane.

  • The annual methane growth rate in 2020 reached 15 parts per billion—the highest recorded since systematic measurements began in 1983.
  • The methane growth rate record was broken again in 2021 at 17.7 parts per billion.
  • Global methane emissions surged from approximately 550 teragrams between 2010 and 2019 to between 570 and 590 teragrams from 2020 to 2022.

The players

Shushi Peng

A researcher at Peking University and one of the lead authors of the study.

Francesca Hopkins

A climate scientist at the University of California, Riverside, who was not involved in the research.

Euan Nisbet

A scientist who co-authored a commentary accompanying the research.

Martin Manning

A scientist who co-authored a commentary accompanying the research.

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What they’re saying

“We expected that the anthropogenic methane emissions could decrease a little bit.”

— Shushi Peng, Researcher, Peking University (Harlem World Magazine)

“They threw the kitchen sink at the problem.”

— Francesca Hopkins, Climate scientist, University of California, Riverside (Harlem World Magazine)

“As the air becomes cleaner, it means we have fewer methane sinks in the atmosphere. Thus, we need to further decrease anthropogenic emissions.”

— Shushi Peng, Researcher, Peking University (Harlem World Magazine)

“Cutting fossil fuel emissions could 'boost warming because of the methane side of things with the OH radical chemistry,' though she stressed that reducing combustion emissions remains vital to limit climate change.”

— Francesca Hopkins, Climate scientist, University of California, Riverside (Harlem World Magazine)

What’s next

In a commentary accompanying the research, scientists Euan Nisbet and Martin Manning pointed to opportunities for China and India to capture methane from coal mines, landfills, and wastewater treatment facilities.

The takeaway

The findings highlight the complex interplay between air pollution, atmospheric chemistry, and greenhouse gas emissions, presenting a challenge for policymakers who must balance the need for cleaner air with the imperative to limit climate change. Experts say further reductions in anthropogenic emissions, particularly from fossil fuels, are crucial to addressing the surge in methane levels.