Australia’s coal mines have a methane problem. In 2019, they released 68% of Australia’s methane emissions from the energy industry overall, making coal mines a larger contributor than both oil and gas.
What’s more, new evidence suggests emissions are underreported and are actually significantly higher than this.
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.
Methane is a potent and fast-acting greenhouse gas, which is 82.5 times more powerful than carbon dioxide over 20 years, making the task of reducing methane levels even more important in the near-term.
Reducing coal use, and legislating the end of new coal, are crucial to this goal. To tackle leaks immediately, existing technology must be used to directly measure methane emissions as well as capture and/or utilise the methane leaking from active and closed coal mines.
It is up to the Australian government to legislate a robust plan to rapidly reduce leaks in the short term and jump-start a just transition to phase out coal.
Here are the four key points from our report.
Australia’s CMM causes more global heating than all of Australia’s cars
In 2019, coal companies reported via the Australian Greenhouse Emissions Information System (AGEIS) that their mines leaked 898,000 tonnes of methane into the atmosphere, representing 5% of Australia’s total GHG emissions.
Methane’s short-term climate impact is 82.5 times that of carbon dioxide, making the methane released by coal mines equivalent to 74.3 million tonnes of carbon dioxide. This is greater than the 44 million tonnes of car CO2 emissions reported in AGEIS for 2019.
Coal Mine Methane emissions twice as high as official estimates
The IEA estimated that Australian coal mines emitted 1.8 million tonnes of methane in 2021, double the officially reported figures. Independent satellite measurements have also uncovered underreporting of methane emissions from Australian coal mines.
Open-pit mines in particular show the greatest disparity between reported and measured emissions – Hail Creek open pit mine was shown to be leaking more than 10 times the amount reported to regulators.
Emission factor based reporting must be replaced with direct, source and site level methane measurements if Australia aims to seriously address its CMM emissions.
The worst performing coal emits over 10 times more than the least emitting.
In Queensland, the two gassiest mines emitted 24% of reported scope 1 emissions from coal mines, while in New South Wales the two gassiest mines emitted 29%.
Not all coal is equally gassy – the gassiest 25% of coal emits 68% of coal mine emissions whereas the best performing coal only emits 4%. To realise the most impactful emission reductions, efforts should first be concentrated on the gassiest coal mines.
Emissions likely to rise not fall
Australia is the world’s 6th largest coal mine methane emitter and on track to become the 3rd worst. Existing methane leaks aren’t being plugged with any urgency. Mines are not voluntarily stepping up to implement methane abatement technology, and regulation on methane emissions measurement and reporting is patchy.
What’s more, new coal mines are likely to result in further increases in methane leaks, and 45% of these are thermal-only mines. Queensland’s proposed mines will double the state’s current emissions. In NSW, two recently approved mine extensions could emit a further 112 Mt CO2-e in their lifetime.
Dr Sabina Assan is a Coal Mine Methane Analyst at Ember. This is reproduced from the report she authoried.
