A Dutch group of scientists has used the space instrument TROPOMI to calculate methane emissions from six Australian coal mines. Together these account for 7% of the national coal production, but turn out to emit around 55% of what Australia reports for their total coal mining methane emissions.
Australia is in the top-5 coal producing countries in the world. It reports coal mining methane emissions of a million tons per year. ‘It is hard to believe that 7% of coal production is responsible for 55% of coal mining methane emissions,’ says Prof. Ilse Aben (SRON/VU), leading the team of researchers. ‘So in reality, Australia’s coal mining methane emissions are likely much higher than reported. More importantly, knowing which mines have such large emissions is critical in focusing efforts for mitigation.’
The research team observed five underground mines and one surface mine. Especially the emissions from the surface mine, called Hail Creek, stand out. It is one of 73 surface mines in Australia, but accounts for 88% of Australia’s total reported surface coal mine emissions.
First author Pankaj Sadavarte (SRON/TNO): ‘The most remarkable finding is that the emissions from the surface mine are so much higher than expected and by far the largest we see in the TROPOMI data over the coal mine area in Queensland: on its own, it accounts for 40% of emissions for all six observed mines. Common understanding is that surface mines emit much less methane than underground mines. And to be quite honest, we still don’t understand why this mine is emitting so much methane.’
Methane has been recognized as crucial to mitigate climate change in the short term. At the COP26 in Glasgow, over a hundred countries signed the global methane pledge initiative from the US and the EU to reduce methane emissions by 30%—relative to 2020—by 2030. A few major methane emitting countries, including Australia, have not signed the pledge.
TROPOMI methane observations on two different days showing large signals from three coal mine locations. The most Northern location is the surface mine, while the other locations are underground mines. Northern: Hail Creek. Middle: Broadmeadow, Moranbah North, Grosvenor. Southern: Grasstree, Oaky North.
Pankaj Sadavarte, Sudhanshu Pandey, Joannes D. Maasakkers, Alba Lorente, Tobias Borsdorff, Hugo Denier van der Gon, Sander Houweling, Ilse Aben, ‘Methane Emissions from Super-emitting Coal Mines in Australia quantified using TROPOMI Satellite Observations’, Environmental Science & Technology