Australian coal miners emitted 40pc more methane in 2020 than they reported, energy think-tank Ember said in a review of satellite data released today.
The organisation, along with energy intelligence company Kayrros, analysed methane emissions from four mining "clusters" in Queensland in 2020, which account for roughly three fourths of the state's thermal coal and almost all of its coking coal production. The investigators found "a total of 1.42 ± 0.19 million tonnes of methane released from coal mines" in that year. Miners in the state reported 1.01mnt of methane emissions during the same period.
The difference between reported and actual emissions was much larger in New South Wales, Ember said. "While the state reported 379,000t of methane in 2020, our satellite study identified 721,000t of methane that year, while only accounting for approximately 61pc of the state's coal production," the organisation said.
If all coal mines in New South Wales followed the same trend, this would suggest total methane emissions of 1.2mn t, more than three times the figure producers reported to the government.
Ember are not the only organisation criticising Australia's official numbers. Climate Trace and Open Methane, two organisations monitoring greenhouse gas emissions by satellite, suggest that Australian coal miners are only reporting half of their methane emissions. Academics supported by the UN Environment Programme (UNEP), writing in the American Chemical Society, published an article this year saying that trading company Glencore's Hail Creek mine was emitting four to five times more methane than it reported.
Glencore sharply criticised the Hail Creek report, saying the study's aerial surveys lacked credibility because they were based on very limited samples and did not consider "inherent mining variability." The firm said that the report "failed to detect methane emissions" that it had reported itself.
The producer, one of the country's largest, has repeatedly criticised satellite measures of methane emissions. The method, the firm said in a 2022 statement, is vulnerable to "atmospheric contaminants such as dust, water vapour or smoke" and cannot reliably detect the amount of greenhouse gases coming from mines.
The Australian government launched a review of their methane reporting last year in light of the new satellite techniques used by researchers.
The UK and EU are both planning a carbon tax on imported goods called the Carbon Border Adjustment Mechanism (CBAM) in the next two years. If either government were to accept Ember's figures, they could theoretically raise taxes on imported steel made with Australian coking coal. Neither government plans on taxing coal imports directly under CBAM.
