Source: United Nations Economic Commission for Europe
In the fight against climate change, emissions of methane – which has a warming effect over 80 times greater than CO2 over a 20-year timeframe – from coal mines remain a significant source of greenhouse gases (GHG). Coal mines account for over 10% of methane emissions from human activity. As long as coal’s share in the global energy mix remains significant, mitigating large emissions associated with its extraction presents an under-exploited and under-capitalized opportunity to deliver near-term GHG emissions cuts.
Gassy underground coal mines employ large-scale ventilation systems that pump fresh air into the workings to dilute and remove methane released during mining operations. This ventilation air, discharged through dedicated (ventilation) shafts, contains methane in concentrations typically ranging from 0.1% to 1.0% by volume, known as Ventilation Air Methane (VAM). While removing methane from the mine is necessary for maintaining safe underground working conditions, the continuous discharges of large volumes of VAM constitute a significant source of greenhouse gas emissions.
A new UNECE report developed by the UNECE Group of Experts on Coal Mine Methane and Just Transition sheds light on the urgency of tackling VAM emissions. A single ventilation shaft in an operating coal mine can expel up to 50,000 tonnes of methane annually – equivalent to the emissions (CO2e) generated by 2 million cars. Since coal mines are expected to continue to operate for at least the next two decades, reducing these emissions presents an immediate and effective way to slow down climate change, complementing scaled-up decarbonization efforts.
The report “Best Practice Guidance on Ventilation Air Methane Mitigation” highlights the cost-effectiveness of VAM mitigation. Advanced technologies, such as Regenerative Thermal Oxidation (RTO), have been successfully deployed in large-scale, long-term projects, proving the technical viability of VAM mitigation. RTO installations are actively reducing methane emissions at coal mines in the United States and China. For such projects to be economically sustainable, the value of emission reductions must reach approximately USD 20 per tonne of CO2e – an economically feasible target when compared to other climate mitigation efforts.
The cost of a VAM mitigation plant is all about the volume of air being processed, and therefore the methane content in the ventilation air to be processed is a key factor determining the revenue and thus also the economic viability of the plant. A plant processing VAM concentration of 0.2% will have a total cost per mitigated tCO2e around USD $20. Where such mechanisms exist, this cost could be balanced by Carbon Emission Reduction Credits, or by avoided emissions penalty.
Despite its potential, VAM mitigation faces technical challenges. Methane concentrations in ventilation air are often very low, and mine shafts release vast volumes of air. The report emphasizes that only one technology, RTO, has consistently reduced methane emissions from coal mines, though other catalytic processes are emerging.
The report aligns with global efforts to address methane emissions, including the Paris Agreement and the Global Methane Pledge, which aims to cut methane emissions by 30% by 2030. In this context, VAM mitigation could play a key role in achieving these ambitious objectives.
This Best Practice Guidance on VAM serves as a call to action for the mining industry and policymakers, underscoring the significant potential of VAM mitigation as a cost-effective solution to reduce emissions.
The report provides practical guidance on securing financial support, assessing the feasibility of VAM mitigation plants, and understanding the key aspects of technology integration. It also offers a clear 8-step model for preparing potential VAM projects, making this complex topic accessible and actionable.
For further information and/or to access the Best Practice Guidance report, please visit https://unece.org/sustainable-energy/publications/best-practice-guidance-ventilation-air-methane-mitigation
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In addition to the Best Practice Guidance, the UNECE Group of Experts on Coal Mine Methane and Just Transition – through its Task Force on Methane Emissions Reduction – has developed complementary resources to further support methane monitoring and mitigation efforts. These include:
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Template for Estimating Emissions from Underground Coal Mines – A user-friendly tool designed to improve emissions data collection for policymakers and companies. This template streamlines the tracking of methane emissions, destruction, and off-site transportation, and accounts for avoided methane emissions and CO2 emissions resulting from these processes.
Join the Discussion at the UNECE Resource Management Week 2025
The UNECE Resource Management Week 2025 (24–28 March, Geneva), and particularly the meeting of the Group of Experts on Coal Mine Methane and Just Transition, will provide a platform to discuss methane mitigation strategies, including the VAM Best Practice Guidance, which will be presented for endorsement.
Bringing together policymakers, industry representatives, and experts, the event will facilitate discussions on innovative solutions, financing mechanisms, and regulatory approaches to support methane emission reductions.
Register here.