Whitehaven Coal’s plans to expand its mining operations could double the miner’s methane emissions by the end of the decade, undermining Australia’s global climate commitments, global clean energy and climate think tank Ember says.

If the planned and proposed projects go forward, it would roughly double Whitehaven’s annual methane emissions from this year to more than 64,000 tonnes by 2030, according to Ember’s estimates. Between now and 2050, those mines would spew 1.2 million tonnes of this greenhouse gas — an amount that would have a short-term warming impact roughly equivalent to annual emissions from 56 million cars, according to the report.

Whitehaven’s ambitious expansion plans would potentially put it at odds with Canberra’s commitment to slash releases of the potent greenhouse gas as a signatory to the Global Methane Pledge. The international initiative aims to cut global methane emissions by 30 per cent by 2030 from levels at the start of the decade.

Whitehaven has four active mines and said in an email that federal approval to expand its Narrabri project is being finalised. It began construction on its Vickery Extension Project in June, and has submitted an environmental impact statement to Queensland authorities for a new greenfield open-cut coal mine called Winchester South, which is still in the study phase and without a deadline on approving investment.

Whitehaven said in a statement it complies with regulatory processes for emissions management in Australia and that it’s working on improving the accuracy of its emissions forecasting.

Methane has a devastating impact on the climate because it has more than 80 times the warming power of carbon dioxide during its first two decades in the atmosphere. Halting emissions of the potent greenhouse gas is one of the most effective ways to combat climate change and curbing releases now could help reduce temperatures within years.

Methane from coal mining accounted for about a quarter of Australia’s emissions of the gas generated from human activity that the country reported to the United Nations Framework Convention on Climate Change, according to Ember.

Whitehaven’s 2022 methane emissions accounted for 3.2 per cent of the country’s total coal mining methane emissions in 2021, Sabina Assan, a coal mine methane analyst at Ember said in an email citing the latest available data.

There is gross under-reporting of methane emissions from Australia’s fossil fuel sector, according to a report published last month by the Institute for Energy Economics and Financial Analysis, or IEEFA, which cited International Energy Agency estimates. Leaks of methane from oil and gas have likely been underreported by 90 per cent, and for coal by 80 per cent, the IEEFA said.