SYDNEY(BLOOMBERG) - Australia's coal mines cause more planetary warming in a typical year than emissions from all of the country's cars.
If Prime Minister Anthony Albanese wants to meet tougher climate targets, he'll need to fix that.
Satellite observations suggest the best place to start is the Bowen Basin, the major coal hub in Queensland state, and an area where scientists have estimated the methane intensity per unit of production is 47 per cent higher than the global average.
A satellite earlier this month spotted a plume of the potent greenhouse gas that geoanalytics firm Kayrros SAS estimated originated within about 25km of coal mines operated by Anglo American, Stanmore Resources. and BHP Mitsubishi Alliance, known as BMA. The former two companies didn't answer questions from Bloomberg asking if their mines emitted methane the day of the satellite observation. BMA said it estimates and publicly reports emissions in accordance with national requirements.
"Methane leaking from coal mines has been ignored for many years, but tackling it is the 'low hanging fruit' in Australia's effort to combat climate change," Dr Sabina Assan, an analyst with environmental think tank Ember, wrote in a report released this month.
The Bowen Basin has become a global example of the disparity between reported coal mine methane emissions and independent measurements, according to the report.
The powerful green house gas can leak from underground and open-cut coal mines and has 84 times the warming power of carbon dioxide during its first two decades in the atmosphere.
The most recent release, observed on June 3rd by the European Space Agency's Sentinel-5P satellite, was estimated to have an emissions rate of about 12 metric tons of methane an hour and could have come from several mines, according to Kayrros.
Coal production typically runs 24 hours a day, so methane is often emitted constantly from mines. Release levels might fall during maintenance, or rise if miners hit a gas pocket.
If the rate estimated by Kayrros was consistent for a year, the gases would have the same short-term warming impact as the annual emissions from roughly 1.9 million US cars.
Australia's new government, voted into office last month, on Thursday (June 16) confirmed an election pledge to lower carbon emissions by 43 per cent from 2005 levels by 2030, tightening a previous commitment for cuts of 26-28 per cent. In February, Australia disclosed it had revised the method used to calculate methane pollution from open-cut coal mines and said the change means total national emissions were on average 0.3 per cent higher than previously stated for each year since 1990. That revision was prompted by the use of satellite data, which has improved capacity to estimate emissions, the government said.
The change isn't currently reflected in national greenhouse gas reporting legislation.
BMA, which did not use the updated methodology, said based on site-specific measurements of methane and CO2 content in the coal seams and surrounding strata at its Broadmeadow, Peak Downs and Caval Ridge mines cumulatively emitted about 3.32 metric tons of methane an hour on June 3.
When contacted about the June 3 release, Australia's Department of Industry, Science, Energy and Resources didn't say if it was aware of the emissions or investigating them.
"Making reliable, 'top-down' estimates of emissions from the satellite data is difficult for a number of reasons, including challenges associated with a lack of ground-truthing, instrument and modelling errors, and attribution," the department said.
The agency emphasised that coal-mine operators are required to estimate and report company and facility level greenhouse gas emissions under reporting guidelines and that the country's Clean Energy Regulator publishes reported emissions data annually.
But Australia has had problems with some operators who report their own emissions.
Peabody Energy said in January it had made errors in data filed to the local regulator, and appointed an auditor to review its processes.
In Australia's latest report to the United Nations, the government reported that active and abandoned coal mines released about 1 million tons of methane in 2020, while cars generated about 40 million tons of carbon dioxide.