Satellite-based detections and source attribution of methane emissions from underground mines in China

Methane is a potent greenhouse gas and a major contributor to global warming. One of the main anthropogenic contributors to these emissions is the coal sector, which emits most of its methane through ventilation and degasification systems, such as drainage stations in underground mines. In this context, the UNEP’s Methane Alert Response System (MARS) and the Steel Methane Programme (SMP), managed by the International Methane Emissions Observatory (IMEO), have made systematic efforts to identify large emissions associated with coal mines using high-resolution hyperspectral satellites such as EMIT, EnMAP, and PRISMA. These efforts focus particularly on metallurgical coal mines globally, with an emphasis on producing countries such as Kazakhstan, the United States, Poland, Czechia, Russia, Australia, and China, among others.

China is not only one of the world's largest coal producers but also one of the main emitters of methane associated with this activity. This study analyzes emissions and their potential sources from underground mines processing metallurgical, thermal, and mixed coal. The analysis is conducted within the IMEO MARS framework, using spatial information provided by the Global Energy Monitor (GEM) database to identify mine boundaries and potential emission point sources. Based on this information, monitoring areas are defined and integrated into the system, allowing for the acquisition of historical images intersecting these areas and subsequent analysis.

In this study we analyzed the emissions of 94 underground mines distributed across 12 provinces in China. To this end, we processed 600 hyperspectral satellite images acquired between February 2020 and January 2026, applying the wide-window matched filter methodology for the retrieval of the methane concentrations, which is suitable for this study due the heterogeneous environments. Afterwards, through visual inspection, we identified over 700 plumes that were attributed to 150 different emission sources. Among the different sources, we found that 60% of the plumes come from venting shafts, 36% from drainage stations, and 4% from other types of coal facility. Based on this data, we aim to support large scale mine level emission assessment and source specific attribution within the IMEO MARS framework, contributing to improved prioritization of mitigation actions in the coal sector.