Updated greenhouse gas inventory estimates for Indian underground coal mining based on the 2019 IPCC refinements

Underground coal mining has been known as a significant source of fugitive greenhouse gas emissions. Past analyses of these emissions in India used deterministic emission factors and predominantly focused on methane emissions with reporting of CO₂ emissions remaining limited to a few sites. This study addresses these gaps via field measurements on 108 underground mines (out of a total 338) to evolve greenhouse gas reporting in this sector. Results show large heterogeneity across "degrees" of mines as categorized by the Indian government. In addition, CO₂ emissions are found to be significant in shallower mines of lower gassiness. Overall, the emissions from underground mining have reduced from 2.6 to 8.3 Mt-CO₂e to 1.3-3.6 Mt-CO₂e during 1980-2019. These emissions might remain significant by 2050 under a 2-2.5°C constraint or may decline below 100,000 t-CO₂e under a 1.5°C constraint. We also discuss several generalizable outcomes and approaches to make inventories in this sector more robust.