The first coal-producing region in Australia emits methane equivalent to the greenhouse effect of 30m passenger cars on combustion engines, according to a new analysis using satellite data.
The study by energy consultancy group Kayrros shows the Bowen Basin, which stretches across the border between the states of New South Wales and Queensland, has released an average of 1.6 million tonnes to the methane year in 2019 and 2020.
Based on the power of methane as a greenhouse gas, emissions are equivalent to 134 million tonnes of carbon dioxide per year – on par with the CO2 emissions of a medium-sized European country or of 30 meters of combustion engine vehicles.
The Bowen Basin is the largest metallurgical coal export region in the world, with Anglo American and BHP among its major producers. Metallurgical coal is one of the key ingredients needed to make steel.
Methane emissions are the second leading cause of global warming, after carbon dioxide. They have increased at a much faster rate than predicted by scientists, increasing by a record amount last year.
Identifying these leaks can help governments, investors and the public hold companies accountable will accelerate emissions reduction.
Methane leaks, or leaks, can come from a variety of sources, including oil and gas infrastructure, landfills, wetlands, and livestock. The mine also releases methane, with most of the industry’s emissions created during coal mining.
While oil and gas companies have come under pressure to reduce methane emissions, the mining industry has come under less scrutiny even though most large companies are committed to achieving zero net emissions by 2050
The lack of accurate data has been an impediment, but using satellite data from the European Space Agency, Kayrros said it would be possible to measure methane emissions across the Bowen Basin and track its evolution over time.
Bryce Kelly, an associate professor at the University of New South Wales, said satellite-based methane emission estimates were significant because they indicated “where we should be targeting mitigation costs to minimize or eliminate ‘use of emission-intensive goods’.
However, Kelly said the Kayrros report needed verification higher resolution terrain and low-level air studies. “We have little information to control the results because there is a lack of data in the public domain and a lack of independent measurement and control,” he said.
Kayrros said the mining industry has established techniques to capture methane, which can be used to generate electricity on site or sold to local gas networks. These include draining methane from coal seams before they are mined and capturing gas from the mine’s ventilation systems.
Anglo-American said it captured a large chunk of methane emissions. BHP could not immediately be reached for comment.
Miners operating in the Bowen Basin are already capturing half of their potential methane emissions through these methods. If employed on a larger scale, the capture methods could reduce methane emissions by 650,000 tonnes per year without significant investments, equivalent to the removal of 12m of vehicles from the road.
“For a cost that could be measured in tens of millions of dollars, in a couple of years you could reduce something in the order of 50m tonnes of CO2 equivalent per year,” said Christian Lelong, director of natural resources in Kayrros and author of the report. “For me, it’s a mitigation opportunity quite difficult to overcome in terms of scale and cost.”