Methane mitigation potentials and related costs of China's coal mines.

Mitigating methane (CH) emissions from China's coal mines as the largest contributor to anthropogenic CH emissions is vital for limiting global warming. However, the knowledge about CH mitigation potentials and economic costs of Chinese coal mines remain poorly understood, which hinders the formulation of tailored CH mitigation strategies. Here, we estimate and project China's provincial coal mine methane (CMM) emissions, mitigation potentials and costs under various coal production scenarios, by integrating the dynamic emission factors of CMM and key abatement technologies. We find that through continuous coal cuts and available CMM mitigation measures, China's CMM emissions can be reduced by 65%-78% (10.9 Tg-13.1 Tg) in 2060, compared with the 2021 level. CH emissions from abandoned coal mines will far exceed those from coal mining under the 2060 carbon-neutral scenario, especially in northeastern China. It was also found that CMM mitigation is not economically feasible at present, but may be the most cost-effective solution as CO prices increase. All coal-producing provinces can achieve CMM mitigation below 50 RMB/t COe in 2060. Inner Mongolia is identified as a hotspot for CMM mitigation with huge potential and lower cost. Our prospective assessment can provide insights into China's CMM mitigation in response to climate change.