Supporting materials
Methodology
Methane production in cattle
Cattle emit an estimated 154-264 pounds of methane per head, per year. Assuming a single cow releases an average of 220 pounds of methane, 28.2 kt emissions is roughly equivalent to emissions about 283,000 cattle a year.
Comparisons with car CO2 emissions
Carbon dioxide emissions per car in the EU was calculated using UNFCCC reported CO2 emissions for “Cars” using the last reported inventory year (2021). The number of cars in Europe was taken from the ACEA ‘Vehicles in use in Europe’ report, as “passenger cars” in 2021.
Coking coal imports by country
Data refers to coking coal of various qualities, following Harmonised System (HS) codes, along with country-specific extensions. Coal for Pulverized Coal Injection (PCI) is not included.
Coking coal imports data was collected from official websites of respective countries, covering the calendar year of 2023, from January 1 to December 31.
For China, import data are obtained from the General Administration of Customs, People’s Republic of China (HS 27011210 ‘Bituminous coking coal’).
For EU countries, import data are obtained from Eurostate (CN 27011210 ‘Coking coal, whether or not pulverised, non-agglomerated’). EU-intra trade is excluded. The CN code is a further development of the Harmonised System, with additional EU-specific subdivisions.
For India, import data are obtained from the Ministry of Commerce and Industry, Government of India (HS 27011910 ‘Coking coal’).
For Japan, import data are obtained from Japan e-Stat (Coal of coking, which includes HS S270112011, HS 270112091 ‘Heavy coking coal’ and HS 270112092 ‘Other coking coal’).
For South Korea, import data are obtained from the Korea Customs Service (HS 2701121000 ‘Coking coal, heavy’ and HS 2701122000 ‘Other coking coal’).
The challenge of comparing methane and carbon dioxide
Global Warming Potential (GWP) is a measure to express the effects of GHGs in CO2 equivalent terms. Given that CH4 absorbs much more energy when in the atmosphere, but has a shorter lifetime than CO2, the IPCC considers its impact over 20 years (GWP = 82.5) and over 100 years (GWP = 29.8). One of the shortcomings of this metric is that it assumes a constant value of methane’s effects over time, when in reality these effects vary significantly.
Historically, the 100-year value has been used by Governments and in major international agreements on the basis that global warming is a long term challenge.
At Ember, we propose to use the 20-year GWP (GWP20). Climate change is an emergency, and the next 20 years are critical with regards to climate action. Methane’s short atmospheric lifetime means emissions reductions can reduce global heating in the near term.
Throughout the report, we are often required to use the 100-year GWP (GWP100) in order to draw comparisons to companies’ official reporting on GHGs, and Scope 3 emissions. Whenever possible, we provide both the GWP20 and GWP100 values.
“Not an either/or” Carbon dioxide and methane do not need to be compared using GWP as only concerted action against both greenhouse gases will address the current climate crisis.
Additional GHG impact of steel
Methane emissions were converted to CO2-equivalent using the 20-year Global Warming Impact of 82.9.
Additional climate impact to the steel industry due to methane emissions from metallurgical coal was calculated using the global average of CO2 emissions intensity for all production routes (1.92 tonnes CO2 per tonne of crude steel cast).
The additional emission intensity due to methane emissions from metallurgical coal for blast furnace steel was calculated using the global average of CO2 emissions intensity for the blast furnace production route only (2.32 tonnes CO2 per tonne of crude steel cast).
Derived global emission factor for coking coal
To estimate a global emission factor for coking coal, Ember used the IEA coking coal emission estimate for 2024 (9,703,000 tonnes of methane) and global coking coal production in 2023 reported by the Federal Ministry Republic of Austria and International Organising Committee for the World Mining Congress (1,075,305,187 tonnes).
Derived Emission Factors for Australia’s coal
Emission factors were derived from reported methane emissions data to the Clean Energy Regulator via the Safeguard Mechanism for FY2024, and reported mine-by-mine production data from Queensland and New South Wales.
FY2024 coal production data reported by Queensland includes the grade of coal; HCC, SCC, PCI and Thermal. In this analysis, a mine was categorised by the grade of coal which represents 50% or greater of total coal production that year. Coal production data from New South Wales only includes a differentiation between “Metallurgical” and “Thermal” coal categories, where HCC, SCC and PCI are included in the “Metallurgical” coal category.
The emission factor for Australian Metallurgical and Thermal coal was calculated using a weighted average.
Whilst the reporting to the Clean Energy Regulator via the Safeguard Mechanism only applies to coal mines emitting over a threshold of 100,000 tonnes of CO2-e Scope 1 emissions per year, in FY2024, reporting covered a total of 360 million out of 397 million tonnes of coal produced, thus the emissions reported cover 91% of coal production in FY2024.
Comparison with IEA emission factor for coking coal
Due to limited data granularity in New South Wales, the emission factor reported for Australia’s metallurgical coal includes a mix of coal types—namely hard coking coal (HCC), semi-soft coking coal (SCC), and pulverised coal injection (PCI) grades—rather than isolating coking coal alone, as done in the IEA estimates.
Ember’s analysis found average methane emission factors of 3 tonnes CH4 per kilotonne (kt) for Australian metallurgical coal, and 1 tonne CH4/kt for thermal coal. For Queensland coking coal specifically, the calculated emission factor was 2.6 tonnes CH4/kt.
While Ember acknowledges that a direct comparison between the IEA’s coking coal emission factor and Australia’s broader metallurgical coal figure is not precise, we assess that the difference is negligible and therefore is unlikely to significantly affect the overall findings of this report.
Coal mine methane mitigation potential and cost
CMM mitigation potential and costs for Australia’s metallurgical coal mines are collected from IEA’s methane tracker data tool, which suggests a total 867 kt of methane emissions. Within this, 388 kt (45%) of methane emissions could be avoided via existing technologies, such as drained CMM utilisation, flare, on–site recovery and use, VAM oxidation, efficiency improvements, and capture fugitives and route to abatement. 333 kt (38%) of total emissions could be cut at a cost lower than the the ACCUs average price $23.15 USD in 2024.
The average cost of mitigation is converted to USD/tCO2e using assumptions of methane energy density of 55 MJ/kg and methane global warming potential of 28.
The ACCU market spot price averaged about $35 AUD in 2024. This is equivalent to $23.18 USD, using the Australian Government’s average exchange rate for FY2024, 1 AUD = 0.6624 USD.
Estimated coal mine methane in steelmakers’ value chain
This was based on the total consumption of metallurgical coal (coking coal and PCI) and disclosed Scope 3 emissions companies’ respective annual and sustainability reports.
Ember used reported data of FY2024 for ArcelorMittal and POSCO, and FY2023 for Nippon Steel.
To estimate the methane emissions associated with the coal procured by the three steel companies, Ember used the derived emissions factors for individual coal mines in Australia, multiplied by procurement records identified through KPLER’s seaborne trade data.
For coal sourcing from unidentified mines in Australia, Ember used the average emission factor for Australia estimated by the IEA.
For the remaining coal, calculated by [Company reported consumption] – [Identified imports from Australia], Ember used a derived global emission factor for coking coal, which is derived from IEA’s estimate.
In this report, Ember assumed the FY2024 emission factor was consistent for emissions in FY2023.
Underporting of coal mine methane in Australia
The underreporting refers to discrepancies between official reported methane emissions and estimates derived from independent measurements (e.g. satellite or aerial monitoring data) or internationally accepted emission factors.
At the Hail Creek coal mine, operator-reported methane emissions appear to be significantly underreported relative to independent satellite or aerial estimates. This underreporting raises concerns about the accuracy of data submitted under Australia’s National Greenhouse and Energy Reporting (NGER) Scheme, and highlights broader challenges in ensuring that mine-level emissions are transparently and consistently measured.
Hail Creek trade data
Ember analysed two data sets to determine the Hail Creek trade data, over the period of FY2023 and FY2024. Seaborne trade data was procured through the KPLER data provider, and compared to official export data reported by Queensland for the Hail Creek Mine.
All buyer data outside of the EU was directly identified by KPLER.
Within the EU/ArcelorMittal: According to the official Queensland export data, Hail Creek exported a significant proportion of coal to Luxembourg, the headquarters of ArcelorMittal in Europe, and Switzerland, the location of a number of company headquarters, including the owners of the Hail Creek mine, Glencore. The trade data indicated shipments of Hail Creek coal to France, Germany, Spain and the Netherlands.
ArcelorMitattal was directly identified as the buyer for Hail Creek coal from the ports of ArcelorMittal Dunkerque, ArcelorMittal Ghent and ArcelorMittal Fos Sur Mer. As ArcelorMittal is the sole owner of blast furnace operations in Spain, and the sole blast furnace operating company in Poland with headquarters in Luxembourg, in this analysis, we assume that all the coal sold to Luxembourg was imported by ArcelorMittal for its EU operations. As such, coal exported to Gdansk MPT, Poland and Gijon MPT, Spain were assumed to be ArcelorMittal procurement..
Emissions from Hail Creek: To estimate the emissions associated with the coal procured by steel companies, Ember calculated an emission factor based on Hail Creek reporting in FY2023 (1 t CH4/kt coal) and FY2024 (4.8 t CH4/kt coal). The hidden, or underreported emissions were calculated based on the emission factor developed by the UN IMEO and University of Bremen study for FY2024, as 9.5 t CH4/kt coal. Ember assumed the FY2024 emission factor was consistent for emissions in FY2023.
Contextual information
Data sheet
Data used in the analysis, including metallurgical coal methane emission intensity data, average additional climate impact, stock of blast furnaces in the EU, Japan and South Korea can be downloaded here.
Acknowledgement
Disclaimer
The analysis, interpretations and opinions expressed in this report are solely those of the authors. While reasonable efforts have been made to ensure accuracy, the content is provided for general information only and without warranty. No liability is accepted for loss or damage arising from reliance on this material. Third party content is used under fair dealing for purposes of commentary and criticism under the Copyright, Designs and Patents Act 1988. Any concerns regarding accuracy should be directed to the publisher.
Contributors
We extend our gratitude to our funders, Boundless Earth and Global Methane Hub, for their generous support.
This work was significantly improved by the contributions of Rini Sucahyo, Reynaldo Dizon, Dody Setiawan, Rajasekhar Modadugu, Nishant Bhardwaj, Tito Das, Izabela Urbańska, Ali Candlin, Jan Balcerowski, Ardhi Arsala Rahmani, Sachin Sreejith, Claire Kaelin and Chelsea Bruce-Lockhart.
We thank our external reviewers Lisette van Niekerk, Roland Kupers (UNEP’s IMEO), Romain Su, Anand Pathanjali, Sam Daniel (SteelWatch), Valentin Vogl (ARIA), Jasmine Fowler-Morrow, Fiona Deutsch (ACCR) and Kenta Kubokawa (TransitionAsia).
Photo
Coal stockpiles and machinery at Hay Point, one of Australia’s major coal export terminals in Queensland, Australia.
Credit: Tammy Walker / iStock Editorial
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