New Delhi: The climate impact of methane emissions, including by India that is among the top five emitters, from proposed coal mines worldwide could rival the CO2 emissions from all the US coal plants, warned a new report by Global Energy Monitor on Friday.
For India, the report estimates methane emissions to be at 45 million tonnes (Mt) of CO2 equivalent emissions over a 20-year horizon and estimates proposed new coal mines to be 52.
The first-of-its-kind analysis surveyed 432 proposed coal mines globally and modelled methane emission estimates at the individual mine level.
Unless mitigated, methane emissions from these proposed mines would amount to 13.5 Mt of methane annually, a 30 per cent increase over current methane emissions.
Methane is the second biggest contributor to global warming after CO2, with a shorter atmospheric lifetime, but much stronger potency and warming potential.
During mining, fractured coal seams and surrounding strata emit methane into the atmosphere.
Ryan Driskell Tate, a research analyst at Global Energy Monitor and author of the study, told IANS: "Coal mine methane has dodged scrutiny for years even though there's clear evidence it poses a significant climate impact."
"If new coal mines proceed as planned, without mitigation measures in place, then a major source of greenhouse gas will go unrestrained."
According to the report, coal mines currently under development would leak 1,135 Mt of annual CO2-equivalent (CO2e) on a 20-year horizon and 378 Mt of annual CO2e on a 100-year horizon.
Based on a 20-year horizon, estimated emissions would exceed the annual CO2 emissions from the US coal plants (952 Mt in 2019).
The countries with the highest amount of methane emissions (CO2e20) from proposed coal mines are China (572 Mt), Australia (233 Mt), Russia (125 Mt), India (45 Mt), South Africa (34 Mt), the US (28 Mt), and Canada (17 Mt).
Proposed coal mines in China, the US, Turkey, Poland, and Uzbekistan could emit 40-50 per cent of their greenhouse gas emissions in the form of methane, making them among the gassiest proposed coal mines in the world.