China will impose tougher curbs on the amount of methane released during coal extraction in an effort to reduce emissions of the powerful climate-warming gas, the environment ministry said on Thursday.

Though methane is a significantly more potent greenhouse gas than carbon dioxide, it remains in the atmosphere for only about 10 years, compared to 1,000 years for CO2, meaning that a rapid cut in emissions could curb warming relatively quickly.

More than 150 countries have already pledged to cut methane by 30% by 2030. China, the world's biggest emitter, has yet to commit to a target but it promised last year to capture more methane from mines and tighten controls in livestock farms and landfill sites.

"Controlling methane emissions in an active, steady and orderly manner will have the climate benefit of slowing global temperature rises, the economic benefit of utilising energy resources... and the safety benefit of reducing work accidents," a ministry spokesman said on Thursday.

Under the new rules, mines releasing emissions with methane content of 8% or higher - and amounting to more than 10 cubic metres of pure methane per minute - must capture the gas. Gas that cannot be utilised must be destroyed.

The number has been reduced from the previous threshold of 30%, which was set in 2008 with the aim of preventing mine explosions and promoting the use of coalbed methane as fuel.

All new mines will have to comply with the rules by April next year, while existing mines will be given until April 2027, the ministry said.

China's 3,000 coal mines are responsible for around 40% of the country's methane emissions, with a similar amount generated from agricultural activities.

Satellites have observed as many as 23 large-scale methane plumes from coalmines in China, Australia, Colombia and Mexico between Jan. 1, 2023 and April 1, 2024, the think tank Global Energy Monitor (GEM) said in research published on Thursday.

Reuters

Dunes of low-grade coal are seen near a coal mine in Ruzhou, Henan province, China November 4, 2021. Picture taken November 4, 2021. REUTERS/Aly Song/File Photo

China tightens rules to curb methane emissions from coal mines