A new research conducted by the International Energy Agency (IEA) uncovered that coal mines do emit millions of tonnes of methane into the atmosphere. The study added policymakers had overlooked the rising climate threat.

IEA calculated that the amount of methane seeping from new and disused coalmines might have reached just nearly 40 million tonnes last year. Climate scientists expressed their concern over greenhouse gas as it has a far stronger effect on global temperatures than carbon dioxide.

The global energy watchdog estimates that one tonne of methane is equivalent to 30 tonnes of carbon dioxide. The measurements would set yearly coal mine emissions broadly in line with the international aviation and shipping sectors combined.

Carbon emissions from the global energy industry had reached a new record in 2018 despite a boom in renewable energy in recent years, IEA revealed in the same report.

The research is among the first major global investigations examining the problem of methane emissions from coal mines. The results may help to explain the sudden surge in methane emissions in recent years.

The global coal industry is "more polluting" than people thought - environmentalists

Dave Jones, an analyst at the climate think tank Sandbag, told The Guardian coal firms should face stricter regulation as the industry pollutes more than everyone thought.

"Having such high-profile global research from the IEA showing such a big impact should help shock policymakers to address coal mine methane." 

- Dave Jones, analyst, Sandbag

Jones urged the government to begin reckoning for the emissions from manufacturing coal, including methane leakage, on top of the pollution created by burning it to produce electricity.

Methane leakage from coal mines would prove to be more challenging to tackle than methane pollution from the oil and gas industry, according to IEA. The firm added they did not expect the situation to worsen before 2040.

The IEA said oil manufacturers could freely stop methane leaks if these companies trap the greenhouse gas and sell it on to the manufacturers. However, the emissions from coal mines would be tricky as the methane concentration released by mines are often very low.

"The lower the concentration of methane, the more technically and economically [challenging] it is to [lessen]," IEA said.

The energy authority examined the emission reports from the miners and mining industry studies from India and China. The researchers from the United States examined these findings into satellite-based estimates of every country's total methane discharges.

The results said deeper coal seams point to having more methane than shallower seams. Older seams, on the other hand, have higher methane content than younger seams. The findings were used over all the countries with coal mines to determine the global scourge of coalmine methane.

China's vast number of coal mines, of which many are more than 100 meters deep, suggests it is by far the largest source of coalmine emissions. Australia, India, and Russia are likewise among the world's worst coal mine methane producers.

The landfills in California also among the top emitters of methane in the United States. According to scientists, methane is targeted for emissions mitigation worldwide.