Countries that identified methane-focused mitigation measures in their NDCs. Each row represents the mitigation actions in three different sectors: agriculture (top row), waste management (middle row) and fossil fuels (bottom row). Each map shows a particular sub-sector for mitigation, for example, livestock enteric fermentation (upper left corner). Countries in blue (red) have (have not) signed the Global Methane Pledge. Countries in white do not present any methane mitigation strategies in their NDCs. Source: Malley et al. (2023)
The researchers found that if all 476 methane mitigation actions were fully implemented, global human-caused methane emissions would be slashed by about 31 per cent. Therefore, they would achieve the Global Methane Pledge goal, which aims to reduce 30 per cent of global methane emissions by 30 per cent in 2030.
The paper also breaks down mitigation actions by sector. For instance, measures to reduce “fugitive” methane emissions leaking during oil production were included by 18 per cent of countries.
Actions to reduce on-farm emissions from manure management and livestock were pledged by 30 per cent of nations.
Capturing landfill gas – which is created by decomposing organic matter – was mentioned by 59 per cent of countries.
The study concludes that to limit global warming to 1.5°C, a greater ambition of methane reduction actions is needed, including individual behavioural measures – such as shifting to low methane-emitting diets and reducing organic waste generation – as well as the participation of countries that have not yet signed the pledge.
Even before the Global Methane Pledge, there had been an increase in policies and measures to reduce methane emissions.
This IEA chart of new policies since 2010 shows that most of them have been implemented at a national level (dark blue). Since 2021, there has been an uptick in international policies aimed at cutting methane (light blue).
Policies and measures related to methane abatement from 2010-22. Dark blue accounts for national policies and measures; light blue represents the international ones. Source: IEA. Chart by Carbon Brief
Since the Global Methane Pledge, a number of countries have published their specific plans on reducing methane.
In 2021, the US launched its methane emissions reduction action plan to cut emissions from oil and gas production by 75 per cent and from agriculture by 10 per cent. In 2022, Canada announced its methane strategy to cut 35 per cent of methane emissions by 2030, including 75 per cent of methane emissions from oil and gas production.
Also in 2022, the EU and US, along with 11 other countries, launched the Global Methane Pledge Energy Pathway, to accelerate methane emissions reductions from the oil and gas sector.
In 2023, China issued a methane action plan, which includes 20 “key tasks” for reducing methane, such as emissions monitoring and developing policy frameworks. However, it lacks numerical targets, as Carbon Brief reported at the time.
Developing countries are also crucial to reducing methane emissions, says Dr Marcelo Mena, chief executive of the Global Methane Hub, a philanthropic organisation that supports countries in fulfilling their commitments under the Global Methane Pledge.
Mena tells Carbon Brief:
“Overall, methane mitigation has been approached from the energy sector standpoint. For countries that do not have oil and gas production, how will they lower emissions in the waste and livestock sector? There is a lot of work to be done.”
Less than 2 per cent of global climate finance – totalling just over US$10 billion – was targeted at methane mitigation in 2019-20, according to an analysis by the not-for-profit research group Climate Policy Initiative.
The report highlights that current methane mitigation investment “is not enough to limit global warming to 1.5°C” and must grow at least tenfold to meet the US$110 billion of private and public finance needed for the world to be 1.5°C-aligned.
It adds that most methane finance was allocated in east Asia and the Pacific – the largest methane-emitting region – but Latin America, the Caribbean and sub-Saharan Africa all have “significant abatement potential”.
What are the biggest sources of methane emissions?
Agriculture
Agriculture is a significant source of methane – accounting for almost half of human-caused emissions, according to the IPCC. Livestock alone causes around 30 per cent of human-caused methane emissions.
Methane emissions from agriculture and waste rose by one-sixth over 2000-20, according to the new Global Methane Budget.
Agriculture and livestock are responsible for the vast majority of methane emissions in countries with big farming sectors, such as New Zealand, Brazil and Ireland .
Almost 90 per cent of New Zealand’s methane emissions trace back to agriculture. The country also has among the highest methane emissions per capita, ranking alongside fossil-fuel-producing countries such as Turkmenistan.
In Denmark, another big agricultural producer, the government recently proposed a world-first tax on greenhouse gas emissions from agriculture to help meet climate goals.
Methane is emitted through enteric fermentation, which takes place in the digestive system of ruminant animals, such as cows and sheep. The gas is produced by bacteria in the stomach during this process and then expelled from the animal, entering the atmosphere.
Daffodils, seaweed and other items are being tested as livestock feed to try and lower methane emissions. “Methane blockers” have also been proposed to reduce emissions from UK cows, alongside government-funded projects aimed to breed sheep with lower emissions. A methane-cutting vaccine is also in the works.
These projects are ongoing, with mixed results. A major commercial trial of a seaweed supplement for cattle in Australia saw methane emissions drop by 28 per cent, rather than the “widely promoted” reduction of more than 80 per cent, the Guardian reported.
In a separate Guardian article, a Swedish report found more promising methane reduction potential from feeding a type of seaweed to cows, but noted that more knowledge is needed.
Other agricultural methane emissions arise from the storage of animal manure. A 2023 study reviewed different methane-cutting methods of manure management, including aeration, slurry covers and chemical treatments.
Growing rice also leads to methane emissions. The staple crop for billions of people around the world accounts for around 8 per cent of human-caused methane emissions, according to the UN. The gas is generated by decomposing organic matter in flooded rice fields.
In 2023, the World Bank approved a US$255m loan to support a programme to reduce methane emissions and enhance “climate-resilient” rice production in Hunan province in China, one of the country’s biggest rice-producers.
Trials to reduce water usage and methane emissions and produce more rice have been gaining traction in China.
In other parts of Asia, different solutions aim to cut methane emissions from rice fields by draining and re-flooding fields more frequently.
Fossil fuels
About a third of human-caused global methane emissions come from the energy sector, according to the IEA.
Methane emissions in the fossil fuel sector come from different processes, including leaks at different stages of oil, natural gas and coal operations and flaring natural gas – the burning of natural gas during oil extraction.
Efforts are underway to improve methane emissions measurements from oil and gas, from global to sub-national levels.
An international initiative called the Oil and Gas Methane Partnership 2.0, organised by the UN Environment Programme, lays out a set of practices for companies and organisations to ensure they will accurately and transparently report their fossil methane emissions. To date, 100 companies– accounting for 35 per cent of oil and gas production – are part of the initiative.
The partnership is starting to see improvements in methane measurements, says Dr Paul Balcombe, senior lecturer in chemical engineering and renewable energy at Queen Mary University of London.
In 2020, the European Commission published its methane strategy, which will improve the detection and repair of leaks in gas infrastructure.
The EU methane strategy was complemented by a methane emissions regulation – proposed in 2021 and passed in May this year – which seeks to compel fossil fuel companies in the EU to measure, report and reduce their methane emissions, as well as those from fossil energy imports to the EU. Under this regulation, oil and gas producers are required to report their estimated emissions within 12 months after it comes into force.
This EU import standard could reduce one-third of global methane emissions from the oil and gas sector, according to an analysis by the Clean Air Task Force.
The regulation also orders fossil-fuel companies to “stop avoidable and routine flaring” and to carry out flaring and venting only in cases where it is “necessary for safety reasons”.
Dr Zitely Tzompa Sosa, research manager of the Methane Pollution Prevention team at the Clean Air Task Force, says global regulations have slowly moved from an engineering calculation-base to a measuring-base emissions inventory.
Under an engineering calculation approach, companies use data, such as the number of facilities multiplied by standardised emission factors, to estimate methane emissions. By contrast, a measuring-based inventory entails companies measuring their emissions through aeroplanes, drones or satellites, which improve their measurements by detecting major and small leaks of methane.
Tzompa Sosa adds that using measurements and emissions verification is critical to addressing methane emissions. She tells Carbon Brief:
“Verifying is key [to seeing that] your targets are being met. We don’t only want to be reducing reported emissions; we want to reduce real, immediate methane.”
For Balcombe, to reduce methane emissions in the oil and gas sector, countries and companies should understand their methane emissions and commit to fulfilling their methane targets. He says:
“Almost every possible emission source is possible to eliminate, but [companies] have to know about it, improve the design or operation of [their] equipment and work with [those] who are on the plant to understand that methane emissions and safety [are] a priority.”
According to an IEA report, “targeted actions”, such as repairing leaks to reduce methane emissions from fossil fuel production and use, are crucial to keeping warming to no more than 1.5°C.
However, policies aiming to reduce fossil methane emissions have been less stringent than those for waste, according to a 2023 study. It adds that regulations primarily address emissions from burning (flaring) and intentional release (venting) of methane, rather than addressing fugitive emissions or abandoned oil and gas wells, which can continue to leak methane if not properly sealed off.
The study recommends economic instruments to incentivise companies to invest in emissions reduction, such as emission trading systems, taxes and fiscal instruments. It also suggests regulating methane emissions at each stage of a project, including abandoned facilities.
Wetlands
Around one-third of total global methane emissions come from natural sources – mainly wetlands, but also oceans and termites.
A wetland is an ecosystem that is covered in water for all or most of the year, including Arctic permafrost peatlands, tropical mangrove plantations and salt marshes.
When in good condition, wetlands provide key ecosystem services such as water filtration and are important carbon sinks.
When they are degraded, wetlands can release greenhouse gases including methane, CO2 and nitrous oxide back into the atmosphere. Vast swathes of wetland are degraded, with a 2023 study finding that Europe, the US and China have been worst hit by wetland loss.
The waterlogged soils are releasing methane into the atmosphere more rapidly as climate change raises global temperatures and disrupts rainfall patterns. This is called the “wetland methane feedback”.
The 2023 research found that global warming “undermines the mitigation potential of pristine wetlands” and adds that there is “major uncertainty” over whether wetlands will remain a carbon sink as the planet warms. Allen tells Carbon Brief:
“Trying to manage wetlands, that’s a massive geoengineering task. You’d have to control the hydrology of wetland systems in pristine areas, in the tropics, in Africa…Really there is very little we can do on land management to control those biogenic emissions.”
Landfill
Food waste and other organic compounds breaking down in landfill sites are another significant cause of methane.
Waste accounts for 19 per cent of global methane emissions from human activities, according to the Global Methane Budget. Greenhouse gases from food loss and waste account for around half of all global food-system emissions.
Earlier this year, the Guardian’s analysis of satellite data showed more than 1,000 “huge” methane leaks from landfill sites around the world since 2019.
Allen says landfill waste is a “growing international problem”– especially in countries with poor landfill regulation.
For example, according to a survey from the UK Environment Agency, one-fifth of all waste in England may be “illegally managed” by being burned, dumped or otherwise disposed of in unofficially managed ways.
Waste management – including landfill – made up around 4 per cent of the UK’s greenhouse gas emissions in 2021, government statistics show. Methane comprised 90 per cent of waste emissions, mostly from landfill sites.
According to the UK’s Climate Change Committee, methane emissions could be reduced by preventing waste, recycling and banning biodegradable waste from landfill, reducing residual waste sent to energy-from-waste plants, increasing landfill methane capture and improving wastewater treatment and compost facilities.
This story was published with permission from Carbon Brief.
