Characterization of methane emissions from coal mining in Australia

In 2022, Australia produced over 450 million tonnes of coal, accounting for approximately 7% of global production. About 75% of this output came from coal mines located in the Bowen Basin (Queensland) and the Hunter Coalfields (New South Wales). According to Australia’s 2022 UNFCCC submissions, open-cut and underground coal mining contributes around one-fifth of the nation’s methane emissions, positioning it as a key focus for methane mitigation efforts. These emissions are calculated using a combination of IPCC Tier 2 methodologies, which rely on average basin-specific coal gas contents, and IPCC Tier 3 methodologies, which involve mine-specific coal core gas distribution modelling. Despite employing higher Tier IPCC reporting methods, top-down studies using the TROpospheric MONitoring Instrument (TROPOMI) have suggested that fugitive methane emissions may be underestimated at some Australian coal mining facilities (Sadavarte et al., 2021; Palmer et al., 2021). However, the spatial resolution of TROPOMI (~7 km by 5.5 km) limits its capability for identifying emissions from individual facilities within an observation footprint cell, which constrains its effectiveness for bottom-up emission verification for individual mines.

Here, we present an overview of findings from a series of mine-scale atmospheric surveys conducted across coal mines in the Bowen Basin between 2022 and 2023, and in the Hunter Coalfields in 2024. These studies utilized aircraft-based in-situ and remote sensing instruments, along with ground-based EM27/SUN Solar Absorption Spectrometers, all capable of isolating methane emission rates from individual coal mine facilities. We discuss the broader implications of these results within the context of Australia’s national and international greenhouse gas reporting framework.

References:

Palmer, P. I., Feng, L., Lunt, M. F., Parker, R. J., Bösch, H., Lan, X., Lorente, A., and Borsdorff, T.: The added value of satellite observations of methane for understanding the contemporary methane budget, Phil. Trans. R. Soc. A., 379, 20210106, https://doi.org/10.1098/rsta.2021.0106, 2021.

 

Sadavarte, P., Pandey, S., Maasakkers, J. D., Lorente, A., Borsdorff, T., van der Gon, H. D., Houweling, S., and Aben, I.: Methane emissions from superemitting coal mines in Australia quantified using TROPOMI satellite observations, Environmental Science & Technology, 55, 16573–16580, https://doi.org/10.1021/acs.est.1c03976, 2021.