Glencore and BHP say methane from ‘gassy’ open-cut coal mines cannot be captured
Satellite imagery suggests emissions may exceed what companies are reporting
Coal producers Glencore and BHP have said there is no way to capture methane emissions from open-cut coal mines as pressure grows from shareholders and governments to reduce emissions.
Methane is a greenhouse gas that is responsible for about 30 per cent of global warming to date, according to the UN’s Intergovernmental Panel on Climate Change.
Last year, the US and EU called on countries to join a pledge to reduce methane emissions by at least 30 per cent by 2030. Australia, the world’s second-largest coal supplier behind Indonesia, declined to join the 113 countries that signed the pledge.
Glencore told the Financial Times that unlike underground mines, there were “no practicable technologies or methods to capture fugitive methane emissions from operating open-cut coal mines”.
“As such these emissions are emitted into the atmosphere,” the company said. Glencore operates 13 open-cut coal mines and four underground mines across Australia. It said it captured some, but not all, emissions from its underground mines.
Open-cut mines, which extract coal from the surface rather than underground, account for the vast majority of BHP and Glencore’s Australian coal mines and the majority of coal mines globally, according to UK-based think-tank Ember. Coal mine methane forms in coal seams and is released during the mining process.
Open-cut mines were previously thought to emit less methane than underground mines. But recent studies by Ember and Dutch space research institute SRON found that some open-cut mines were also big methane emitters and alleged that companies were routinely under-reporting methane emissions at some mines.
SRON’s satellite imagery suggested Glencore’s Hail Creek mine in north-eastern Australia emitted 13 times more methane than the company reported in 2019.
Glencore declined to provide its own estimates for methane emissions from its Australian coal mines.
Fiona Wild, vice-president of sustainability and climate change at BHP, said it was “extremely hard” to capture methane emissions from open cut coal mines.
“A technological solution does not currently exist,” she said, comparing an open-cut mine to a dish where the emissions are widely dispersed over a large surface area, in contrast to bottlelike underground mines in which gas is funnelled up to a single small exit point and easily captured.
BHP and Ember are working with the UN to address methane emissions from metallurgical coal mining.
Sabina Assan, a coal mine methane analyst at Ember, said satellite imagery had debunked the assumption that open-cut mines emitted less methane than underground mines.
“If emissions are that high, we are going to have to develop new technology, or stop mining open-cut so intensively,” she said, adding development may have to stop altogether on the particularly “gassy” mines such as Glencore’s Hail Creek.
Ember this month reported that Australian coal mines emitted more methane than the country’s large natural gas sector, and contributed almost twice as much to global warming as the country’s cars. The International Energy Agency found in February that global methane emissions from coal mining were greater than those from either oil or gas production.
Tim Buckley, an energy analyst and director of Climate Energy Finance, said investors were becoming increasingly concerned about methane emissions.
“This is a material issue, because companies are materially and consistently underestimating their methane emissions,” he said.
The Australasian Centre for Corporate Responsibility, an activist group, last week called on Glencore to provide more accurate estimates of its methane emissions using “best practice technologies, such as satellite, aerial and on ground methane surveys”.