A recent study published in Environmental Science and Technology Letters reveals that methane emissions from the Hail Creek open-cut coal mine in Queensland’s Bowen Basin may be significantly higher than previously reported.
The research, conducted by an international team led by the United Nations Environment Programme’s International Methane Emissions Observatory (IMEO) with participation from UNSW Sydney researchers, indicates that the mine’s methane emissions could be three to eight times greater than the operator’s reported annual average for the 2023 financial year.
The team employed two research aircraft equipped with specialised instruments to measure methane plumes downwind of the mine in September 2023.
By comparing these direct measurements with the operator’s reported emissions, researchers found substantial discrepancies.
“Our airborne measurements are further evidence that emissions from the mine are not well-captured using state-wide emission factors,” said Dr Stephen Harris, a co-author from the UNSW ESSRC Greenhouse Gas (GHG) Measurement team.
Methane is a potent greenhouse gas, with over 80 times the warming power of carbon dioxide over a 20-year period.
The findings of this study underscore the urgency for more accurate and independent verification of methane emissions from coal mines.
“This case study highlights how atmospheric chemistry observations can guide the refinement of current coal-core-based methods for estimating methane emissions from open-cut coal mining,” said UNSW Associate Professor Bryce Kelly.
The study also coincides with the Australian government’s decision to phase out the use of state-wide emission factors for estimating fugitive methane emissions from open-cut coal mines.
The Bowen Basin, where the Hail Creek mine is located, is a major source of metallurgical coal used in steel production.
IMEO estimates that methane released from met coal extraction contributes to approximately a quarter of steel’s climate impact and that better management of these emissions could be achieved at a fraction of the cost of making steel.
“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,” said Manfredi Caltagirone, Head of IMEO.
