At the Cop26 summit in Glasgow, 104 countries have signed a commitment to reduce their methane emissions by 30% between 2020 and 2030.
The initiative has been led by the United States and the European Union and commits countries to cut down on emissions from methane, a greenhouse gas 80 times more potent than carbon dioxide in the short term.
Launching the pledge, European Commission president Ursula Von Der Leyen said: “Cutting back on methane emissions is one of the most effective things we can do… to keep to 1.5C. It is the lowest hanging fruit.”
She and US president Joe Biden stressed the non-climate benefits of reducing methane emissions too. Methane pollution contributes to asthma and other breathing problems and reduces crop yields, leading to poverty and hunger.
Vietnam’s president Nguyen Xuan Phuc called on rich countries to support developing ones in reducing methane emissions by giving finance and sharing technology and expertise.
He said: “This will enable developing poor countries to join in the reduction of methane emission in an effective way, thus contributing to the protection of our planet for a green, safe and sustainable earth.”
While most developed economies and many developing ones signed up for the pledge, big polluters including China, India, Russia, Australia, Turkey and South Africa did not.
Australia’s decision not to sign is thought to be a concession to the junior coalition partner in government. The National Party’s leader has said a 30% reduction in methane emissions would devastate the beef, feedlot, dairy and coal mining industries.
Methane escapes into the atmosphere in various ways including the process of producing coal, oil and gas; from landfills and from agriculture.
In its latest major climate science report in August, the Intergovernmental Panel on Climate Change highlighted that methane levels in the air were at their highest level in 800,000 years.
Activists have used infrared cameras and methane monitors in recent years to show that methane emissions from oil and gas installations go widely underreported, calling for tighter regulation.
Campaigners welcomed the widespread adoption of the pledge. Dave Jones of think-tank Ember said: “The Global Methane Pledge is a game changing moment – it shows that the world is waking up to methane’s staggering climate impact.”
Ember analysis found that methane leaks from the world’s coal mines alone have a short-term warming impact greater than the entire EU’s carbon dioxide emissions.
Jones said: “For countries to cut as much methane as possible, they must target all sources. Coal mine methane is fairly quick and cheap to do something about and a massive contributor to global heating.”
Ani Dasgupta, CEO of the World Resources Institute said the move “can make a real difference”. He said: “Never before have countries come together to tackle this key part of the climate puzzle.”
He added: “The next step is for countries to put the pledge in motion with serious policies across agriculture, energy and waste. Solutions to tackle methane are readily available, cost-effective and bring wins for climate and development.”
But others said that countries should phase out fossil fuel production rather than just making the process cleaner. Earthworks thermographer Sharon Wilson said “the era of ever expanding oil and gas must stop”.
Methane from oil and gas production can be reduced by leak detection and repair and by capturing the gas to use as fuel rather than treating it as a waste product.
The US Environmental Protection Agency opened a public consultation on Tuesday on new rules to curb methane emissions from the oil and gas industry.
Some campaigners said Biden needed to go further and phase out fossil fuel production.
“We’re out of time to tinker around the edges on climate,” said Jean Su, energy justice director at the Center for Biological Diversity. “If Biden wants to be a true climate leader, he needs to set a near-zero methane leakage rate and end new oil and gas project approvals.”
Other ways to cut methane include capturing emissions from landfill sites to burn for electricity and changing the diet of cattle or reducing the headcount.