By Leslie Hook
Experts concerned about how levels of the gas will affect global warming
Methane levels in the atmosphere surged during 2020, marking the biggest increase since records began in 1983, in what scientists called a worrying development for the planet.
New data showed both methane and carbon dioxide reached record amounts in the atmosphere last year, despite the coronavirus pandemic bringing much of the world’s economy to a halt.
Lori Bruhwiler, physical scientist at the US National Oceanic and Atmospheric Administration, said the jump in methane levels was “fairly surprising — and disturbing”.
“We don’t usually expect them to jump abruptly in a year,” said Bruhwiler. The exact reasons for the increase are not yet known, she added.
Methane, which is 28 times more potent than carbon dioxide as a factor in global warning, comes from using fossil fuels such as coal and gas and from microbial sources in wetlands, cows and landfill.
About 60 per cent of methane emissions are linked to human activity, while the rest arise naturally from environments such as swamps or melting permafrost.
The NOAA data show that methane concentrations rose by 14.7 parts per billion in 2020.
Levels of carbon dioxide rose to 412.5 parts per million during 2020, according to NOAA, about 12 per cent higher than the levels in 2000.
Carbon dioxide emissions fell about 6 per cent last year because of the pandemic but, despite the reprieve, the concentration of CO2 in the atmosphere still rose as emissions continued.
The record CO2 levels of were expected because the gas stays in the atmosphere for up to 100 years, but the sudden increase in methane concentrations came as a surprise.
“It is very scary indeed,” said Euan Nisbet, professor of earth sciences at Royal Holloway University of London.