What happens when Australia’s methane bubble pops?

A major new update from the International Energy Agency (IEA) reveals that Australia was the world’s sixth largest emitter of methane from coal mines, in 2024.

The 1.7 million tonnes of coal mine methane emitted in 2024 has a climate impact greater than Australia’s entire transport sector, according to analysis by energy analytics group Ember.

Not only are these figures high in absolute terms, they are significantly higher than the numbers Australia reports both domestically and internationally. The IEA’s estimate of total energy sector methane emissions is 2146 kilotonnes. The National Greenhouse and Energy Reporting (NGER) value is a whopping 57% lower, and Australia’s reported methane emissions to the UNFCCC are 36% lower. It is quite a remarkable piece of work, illustrating the sheer scale of the methane underreporting problem:

The IEA’s data also reveals that Australia’s coal mining sector bears the brunt of the responsibility for the dumping of methane gases into the atmosphere, and the subsequent damage done through heating effects, with methane released by coking coal and steam coal promising 77% of the total energy-related methane release (onshore and offshore oil and gas comprise 14.1%).

A recent report from Ember analysing Australia’s coal mine methane data produced their own estimates of government underreporting, estimating 40% greater methane release than government reports. The IEA’s report has a very clear message for the fossil fuel industry: there is simply no excuse for failing to stem the dumping of methane gas into the open atmosphere, given that no real technological breakthroughs are required. Yet the global coal, oil and gas industries have persisted in a deep, ongoing failure to curb this greenhouse gas.

Dr Sabina Assan, methane analyst at energy think tank Ember, said: “The International Energy Agency shows once again that methane emissions from Australia’s coal sector remain drastically underreported. The size of potential emissions should serve as a wake-up call for Australia to align its policies with climate science and commit to rapid cuts in coal mine methane” — one of the cheapest and fastest ways to reduce warming today”.

The methane bubble

Ember have produced detailed analysis and commentary around Australia’s long-running struggles around accurate methane reporting. Dr Assan explained that Australia’s methane emissions tend to show significant discrepancies due to problems in measurement, reporting and verification.

“At the measurement stage, Open cut mines are not required to take actual measurements of methane emissions, they can estimate emissions based on basin or country wide emission factors”, she said. Underground mines do take measurements, but they’re often single point-in-time snapshots that mask variations over longer periods.

The use of ’emissions factors’ is common, though Dr Assan notes that “2025 is the first year in which the mines must disclose methane emissions independently. We have not yet seen any corporate reporting on methane emissions for individual mines independent of regulations”. And there is no independent verification of reporting emissions, or the factors used.

The consequences of switching from significant industry underestimates to more realistic measurements of methane has wide-ranging consequences across Australia’s climate and energy suite. The Safeguard Mechanism sets limits for emissions from large industrial facilities, including most large coal mines, and forces operators to buy carbon offsets if those limits are exceeded.

But the scheme also grants valuable credits if facilities are under their baseline – potentially extremely lucrative. A recent report by the AFR’s Ryan Cropp found that “Glencore’s Collinsville and Clermont mines in Queensland’s Bowen Basin reported emissions reductions of 52 and 59 per cent, respectively, for 2023-24. However, neither facility recorded equivalent changes to production levels or operational efficiencies over the same period”.

Using blunt ’emissions factors’ and averages was obviously inaccurate, but switching to opaque and uncheckable industry self-reports does not seem to have improved the situation at all. We are still only in the early days of discovering what this means for facilities in the safeguard mechanism. However, there is a bigger problem too.

“Failing to account for such a significant chunk of Australia’s GHG emissions could impede achieving 2035 targets, and result in other sectors having to make greater emissions reductions”, said Dr Assan. “Understanding the scale of emissions now, will enable the government to ensure a robust mitigation plan until 2035 – mitigating coal mine methane is after all, one of the fastest ways to reduce methane as the technology already exists”.

According to my collection of historical ‘versions’ of Australia’s quarterly greenhouse gas emissions reports, there have been some historical revisions to Australia’s total methane emissions. Half of this ‘total’ number relates to agriculture, and about half relates to energy, and the most recent quarterly emissions report shows older years have been revised upwards, while more recent years have been revised downwards:

However, these net upwards revisions pale in comparison to the massive revisions to land-use data that I have previously tracked, which have the effect of masking stubbornly stagnant total energy-related emissions:

Notably, Australia is a signatory to the global ‘methane pledge‘, a target of a 30% reduction in total methane emissions by the year 2020. When Australia joined that pledge in December 2022, the total reported methane emissions for 2020 were 122.93 MTCO2-e, meaning a target of 86.05 by the year 2030.

But the latest data, thanks to upwards revisions, shows that 2020 was really 131.02 MTCO2-e, meaning a new target of 91.72 MTCO2-e. As you can see above, the revisions have not been applied equally. The base year has significantly shifted upwards, resulting in an easier 2030 target, and recent years have shifted downwards, also ‘helping’ to achieve the target. This most recent downward revision has ‘nudged’ methane emissions to being closer to the 2030 target:

While revisions to land-use data seem to occur with high frequency and little public consultation or transparency, major and substantial methane data revisions have been on the slow track for the entirety of the Albanese government’s first term.

Ember highlights that the first reports of the underreporting problem arose in 2021, but four years later, Dr Assan says that “the IEA, Australian and international research teams, all continue to find that Australia is still dramatically underreporting coal mine methane emissions, indicating that the Government needs to move faster”.

The Climate Change Authority’s ‘urgent’ recommendations do not seem to have been heeded. The Department of Climate Change, Energy, Environment and Water (DCCEEW)”proposed to take forward only one of a series of integrated recommendations”, Dr Assan said.

 “Unfortunately, the government’s current proposal is to phase out state-based averages, and simply expand company-led reporting (method 2) across all open-cut coal mines. This is without clarity on the recommended method 2 review, and without any changes to the existing methodology, technology or transparency”.

That is a shift from one bad reporting method to another, despite the rising drumbeat of warnings on Australia’s extremely severe methane underreporting problem stemming largely from its fossil fuel extraction sector.

If the Australian government chooses to kick the can down the road, there will likely be a new suite of scandals arising from the incentive and penalty systems of the Safeguard Mechanism, in addition to a torrent of international scrutiny not just around carbon adjustments for trade but around the debate for COP31 in coming months.

If the data do get updated, there will be an overnight increase in the proportion of emissions from the coal mining sector – meaning deeper reductions in other sectors, like energy and transport, will be needed to hit emissions targets.

The sooner Australia’s methane bubble pops, the better. The consequences of dealing with this sooner are far, far lower than letting it continue to fester into the near future. The ongoing analytical work from the IEA, Ember and other researchers shows how urgent this correction this.

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