Australia’s proposed methodology shift risks concealing millions of tonnes of coal mine methane emissions

Following an extensive review of Australia’s coal mine methane emissions reporting from the Climate Change Authority, the Australian government is on the precipice of a methodological shift in the ways open-cut coal mines report their emissions. 

In this report, Ember provides the first known review of the potential impact of this shift, six months after the Climate Change Authority recommended the methodology be thoroughly examined before any further adoption. 

Currently, open-cut coal mines can report their fugitive methane emissions using either state-based emissions factors or company-led estimates. 

While both methods are estimates and lack the ability to accurately capture the nuances of methane emissions at individual mines, Ember’s analysis reveals that millions of tonnes of emissions have been ‘erased’ from Australia’s emissions inventory when coal miners switched from state-based averages to company-led estimates. This unverified reporting shift is something the Australian government is now considering expanding.

Through a review of all open cut mines reporting to the Safeguard mechanism, and an in-depth analysis of ten open cut mines that have utilised company-led estimates, Ember’s report highlights a clear, repeated historical trend that has seen millions of tonnes of emissions wiped off Australia’s emissions reporting, with clear implications for the Safeguard Mechanism. A trend that would likely significantly expand if the country’s remaining mines follow this shift.  

Historical data shows that no known coal mines have reported emissions at or above state-based emissions averages when they have undertaken self-led measurements, and in fact, have instead reported dramatic reductions in methane emissions. A key example in the report is the Adani Carmichael mine, now owned by Bravus. In 2012, Adani estimated emissions for the mine at a level that is 135 times lower than the current Queensland (QLD) state-based emissions average for open-cut coal mines. 

Yancoal and Glencore’s Hunter Valley Operations coal complex has reported methane emissions using company-led estimates since 2016. Ember’s estimate is that the mine has avoided reporting more than 5.5 million tonnes of emissions (CO2-e) as a result.

When BMA’s Caval Ridge coal mine adopted the same methodological approach, the mine’s emissions reporting dropped by close to half a million tonnes of CO2-e per year through the unverifiable reporting shift.

Finally, when Whitehaven’s Maules Creek coal mine shifted their emissions reporting to a company-led estimate in 2019, they went from one of Australia’s highest emitting mines, to reporting emissions 65 times lower than the regional (NSW) default emission factor. As a result, they may have avoided reporting 1.8 million tonnes of CO2-e emissions since. 

These three mines may have collectively avoided reporting nearly 8.5 million tonnes of CO2-e since 2016. In the past two years alone, while using the proposed company-led estimates, they may have avoided an average of 2.7 million tonnes annually. This figure is expected to rise next year. 

These historical estimates were all conducted through a company-led reporting approach that lacks external review, transparent verification, and public availability, that is currently proposed to be expanded and made compulsory across Australia.

The report warns that expanding this approach could pose significant risks to emissions integrity, and calls for the adoption of a more holistic approach to emissions measurement, reporting and top-down verification.

Chris Wright, Climate Strategy Advisor for Coal Mine Methane at Ember, said: “Company-led emissions reporting at coal mines has regularly led to an outcome you would naturally expect; the overnight erasure of hundreds of thousands of tonnes of CO2-e, without any real mitigation or a change in coal mining.”

The need for accurate reporting

The report finds that a simplistic shift towards company-led reporting risks further underestimating Australia’s coal mine methane emissions and undermines efforts to reduce real emissions. 

The current state-based emissions method (Method 1), while not perfect, keeps emissions reporting within the IPCC’s recommended range for open-cut coal mines, and has been able to account for updates in sampling methods over time. In contrast, the proposed company-led estimates (Method 2) has allowed emissions estimates to be reported at levels more than 100 times lower than state averages.

With increasing satellite evidence, it is clear that Australia’s open cut coal mine methane  emissions are not accurately being reported, and may be significantly underestimated. Without extensive amendments to the reporting methodology, increased sampling diversity and critical top-down verification, a company-led approach going forward is highly likely to make this problem worse. 

Chris Wright concluded: “Expanding the existing approach to company-led reporting without holistic improvements to Australia’s sovereign methane measurement and verification capacity will only further undermine the integrity of our emissions inventory, and increase sectoral unfairness across the Safeguard Mechanism.”