A publication from the UN Environment Programme (UNEP) and the Climate and Clean Air Coalition (CCAC) identifies actions to reduce human-caused methane emissions, which are increasing rapidly and account for almost one fifth of global greenhouse gas (GHG) emissions. UNEP Executive Director Inger Anderson said methane reduction is “the strongest lever we have to slow climate change over the next 25 years.”

The Global Methane Assessment, released on 6 May 2021, shows that a 45% reduction is possible by 2030 – which would avoid nearly 0.3°C of global warming by 2045. It would also have significant health benefits including the prevention of 260,000 premature deaths and 775,000 asthma-related hospital visits.

The technologies needed for a significant reduction are already available, and such action is one of the most cost-effective strategies to rapidly reduce the rate of warming. The authors explain that methane in the atmosphere starts to break down quickly, unlike CO2, meaning that reduction efforts can slow global warming in the short-term.

While about 40% of methane emissions come from natural sources, about 60% of it is human-caused. The report provides actions to be implemented in the three sectors responsible for most human-caused methane emissions: fossil fuels, waste, and agriculture. A table suggests specific measures for each sector. For example, in the fossil fuel sector, the report recommends flooding abandoned coal mines and recovering vented gas. Reducing Abandoned Mine Methane (AMM) was also the subject of 2019 guidance from a UN Economic Commission for Europe (UNECE) Group of Experts. 

In the waste sector, organic waste should not be landfilled, and residential wastewater treatment should use secondary/tertiary anaerobic treatment with biogas recovery. In agriculture, the table identifies actions to reduce enteric fermentation in cattle and sheep, and suggests treating manure in biogas digesters, among other practices.

To produce the Assessment, the authors conducted modelling using global composition-climate models to evaluate changes in the Earth’s climate system and surface ozone concentrations from reductions in methane emissions. The assessment results are also available in a web-based decision support tool that allows users to input different methane emissions reduction goals to calculate various benefits at a national level.

The Global Methane Assessment from CCAC and UNEP follows the release of the European Union Methane Strategy in October 2020 to reduce methane emissions. The UNEP press release recalls that the Leaders’ Summit on Climate convened by the US in April 2021 resulted in several calls for reductions in methane and announcements of plans to do so, including from Russia, France, Argentina, and Viet Nam. The Net Zero Producers Forum established by the energy ministries of the US, Canada, Norway, Qatar, and Saudi Arabia intends to create strategies for methane abatement.

A methane expert writing on the SDG Knowledge Hub identifies the UN’s High-Level Dialogue on Energy in September 2021 as an opportunity to consolidate efforts to reduce methane emissions and launch commitments and partnerships to this effect. [Publication: Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions] [Executive Summary]