What’s happening?
A groundbreaking international study has found that methane emissions from the Hail Creek open-cut coal mine in Queensland’s Bowen Basin could be as much as eight times higher than what the mine operator reported for the 2023 financial year (FY2023).
The study, published today in Environmental Science and Technology Letters, was led by the United Nations Environment Programme’s International Methane Emissions Observatory (UNEP’s IMEO) in collaboration with UNSW Sydney researchers and other international scientists.
Using two high-resolution instruments mounted on research aircraft, the team conducted flyovers in September 2023 to measure methane plumes downwind of the mine. Their findings were compared to official data submitted under the National Greenhouse and Energy Reporting (NGER) framework.
Why it matters?
Methane is over 80 times more potent than carbon dioxide in warming the planet over a 20-year period. Australia is one of over 150 countries that signed the Global Methane Pledge in 2022, committing to reduce methane emissions by 30% below 2020 levels by 2030.
However, current reporting from Australian coal mines often relies on state-wide emission factors—broad estimates based on coal production, rather than direct measurements. This study highlights the limitations of these estimates and raises concerns about the reliability of reported emissions.
Dr Stephen Harris, co-author and part of the UNSW ESSRC Greenhouse Gas (GHG) Measurement team, said, “Our airborne measurements are further evidence that emissions from the mine are not well-captured using state-wide emission factors.”
He added, “The results support phasing out these generic reporting methods in favour of more advanced, mine-specific coal gas content modelling for open-cut coal mines in Australia.”
Local Impact
The Bowen Basin is the powerhouse of Australia’s metallurgical coal (or met coal) industry—an essential component in global steel production. That puts Queensland, and communities like Rockhampton that support this industry, at the centre of a much larger climate debate.
The study highlights not only the region’s contributions to industrial output but also its environmental responsibilities. As emissions reporting becomes more rigorous, regulators are likely to increase scrutiny on local mines and push them to adopt better monitoring and mitigation technologies.
By the Numbers:
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Methane emissions from Hail Creek were found to be 3 to 8 times higher than reported in FY2023.
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Methane is 80+ times more damaging to the climate than CO₂ over a 20-year period.
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IMEO reports that managing methane more effectively across the steel supply chain would cost only 1% of the total cost of producing steel.
Zoom In
The flyover measurements used a combination of remote sensing instruments to track methane plumes in real time—providing a more accurate, mine-specific picture.
This is the first study in Australia to independently verify coal mine emissions using aircraft-based observation, setting a precedent for more precise national emissions tracking.
Dr Harris explained, “Atmospheric chemistry observations recorded using aircraft- or satellite-based platforms, as well as other ground-based monitoring systems, are important for quantifying the true emissions from coal mines.”
He added, “These data highlight the potential for the coal sector to measure, verify and mitigate its methane emissions. Reducing methane emissions is a fast, cost-effective way to slow global warming in the near term.”
Zoom Out
Coal mines globally account for about one-third of fossil fuel methane emissions, yet reliable verification methods remain uncommon—especially for open-cut operations.
This study supports Australia’s move to phase out generic emission factors in favour of direct measurement.
UNEP’s IMEO head, Manfredi Caltagirone, said, “There is so much potential for the steel supply chain to step up, rein in its methane emissions, and have a real impact on climate in the coming years.”
He added, “We need better, verified data like those in this study to seize this mitigation opportunity.”
What to Look For Next?
Policymakers at both the state and federal levels are expected to respond to this case study by introducing new reforms. Future efforts may include a broader rollout of aircraft-based monitoring across Australia’s coal mines, upgrades to the National Greenhouse and Energy Reporting (NGER) framework, and increased public pressure for industry transparency.
UNSW Associate Professor Bryce Kelly, who has mapped methane emissions across Australia since 2014, said: “We need precise, reliable data to guide efforts to curb atmospheric pollution and slow climate change.”
He concluded, “This IMEO study has demonstrated a robust approach that can be used throughout Australia to identify reporting anomalies as well as mitigation opportunities.”
