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 CO 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, CO 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-COe to 1.3-3.6 Mt-COe during 1980-2019. These emissions might remain significant by 2050 under a 2-2.5°C constraint or may decline below 100,000 t-COe under a 1.5°C constraint. We also discuss several generalizable outcomes and approaches to make inventories in this sector more robust.