Cutting methane is one of the fastest ways to slow climate change but it could also have an unexpected side effect: delaying the recovery of the ozone layer.
New research from the University of Reading has found that reducing methane makes two other groups of gases more effective at destroying ozone high in the atmosphere.
The study, published in Geophysical Research Letters, found that when methane levels fall, gases linked to halocarbons and nitrous oxide become more chemically active. That means they can break down ozone more quickly.
The researchers said the finding does not mean countries should stop cutting methane.
Methane is the second most important greenhouse gas from human activity after carbon dioxide and reducing it remains one of the quickest ways to slow warming.
But the study warns methane action must be matched by continued efforts to cut other gases that damage the ozone layer.
Dr James Weber, Lead Author from the Department of Meteorology at the University of Reading, said: “The findings do not suggest that cutting methane is the wrong thing to do. Methane is the second-most important greenhouse gas resulting from human activity, after carbon dioxide, and reducing it remains one of the fastest ways to slow climate change, with benefits for air quality as well.”
“The research shows that the ongoing action to reduce emissions of halocarbons and nitrous oxide becomes even more important if countries also cut methane.”
The ozone layer protects life on Earth by filtering out harmful ultraviolet radiation from the sun.
It has been slowly recovering since the 1987 Montreal Protocol phased out many ozone-damaging chemicals, mainly CFCs.
But the new research suggests that by 2100, the total amount of ozone in the atmosphere could be 2.4% lower under a scenario with large methane cuts compared with one without them.
That matters for public health as the study found the area of land exposed to the highest levels of ultraviolet radiation, classed as “extreme” by the World Health Organization, could be 30% to 35% larger by 2070 as a result.
High UV exposure is linked to skin cancer and other health risks.
Copyright © 2026 Energy Live News LtdELN