Australia's Coal Mines: Insights into Methane Emissions

Aircraft-based airborne measurements in Australia's Bowen Basin, planned and conducted by the University of Bremen and Airborne Research Australia, have provided precise data on methane emissions from coal mines. The findings deepen our understanding of the environmental impacts of coal mining.

Man-made methane emissions are a significant contributor to global warming, with coal mining accounting for around a third of global fossil-fuel-related methane emissions. In the fall of 2023, scientists from the Institute of Environmental Physics at the University of Bremen and the independent non-profit research institute Airborne Research Australia (ARA) conducted airborne measurements in Australia's Bowen Basin in Queensland. These were carried out on behalf of the International Methane Emissions Observatory (IMEO) as part of the United Nations Environment Program (UNEP). The aim was to gain a more comprehensive understanding of methane emissions from underground and open pit coal mines. The Bowen Basin is one of the largest coal mining areas in the world. Analyses based on satellite data indicate that methane emissions in this region could be two to ten times higher than officially reported.

Field Campaign with Research Flights in the Bowen Basin

As part of a five-week field campaign, the research team from the University of Bremen, together with experts from ARA, carried out air measurements using the MAMAP2D Light methane imaging spectrometer. The innovative remote sensor from the University of Bremen was installed under the wing of an ARA research aircraft and over 40 research flights were undertaken to detect and quantify methane emissions from various coal mines.

Jorg Hacker, chief scientist at ARA, summarizes his impressions of the campaign: “It was both exhilarating and depressing to fly for days at low altitude over the vast number of huge, deep, open pit coal mines in a landscape that resembled a lunar landscape. To see close-up what mankind is doing to the environment to sustain its ever-increasing demand for energy and resources gives very powerful impressions.”

Sven Krautwurst, the University of Bremen's campaign manager in Australia, emphasizes: "Beside the wonderful landscape in Australia, also from a measurement perspective, Queensland is a great place to be. Observations from instruments, designed and developed over years in the laboratory, can really shine in the estimation and pin-pointing the sources of CH4 emissions in an area dismembered by numerous coal mines partly extending over hundreds of kilometers.”

Andreea Calcan, UNEP IMEOs coordinator for coal mine methane science studies, underscores the campaign’s significance: “This campaign provides a unique opportunity to better understand methane emissions from coal mines in Australia and this supports UNEP IMEO’s goal to quantify global coal mine methane emissions.”

Results and Outlook: New Insights into the Quantification of Methane Emissions

After the team returned to the University of Bremen, the collected data was reviewed together with the Australian researchers. An important finding from this initial evaluation is that many methane emission hotspots from coal mines were recorded with high data quality. This will enable independent methane emission estimates and will help to provide a more complete picture of methane emissions from the various coal mines in the Bowen Basin.

The next detailed analysis of the collected data will provide methane emission estimates for different coal mines, such as underground and open pit mines in the Bowen Basin. These results will be compared with existing estimates based on production data and satellite-based emissions to provide a comprehensive overview of methane emissions.