The Australian High Court has delivered a landmark ruling that could change the future of the country's coal mines. The judges have invalidated the expansion of the Mount Pleasant mine in the Hunter Valley, establishing that authorities must consider not only the emissions produced by coal extraction but also those generated when the fossil fuel is exported and burned abroad.

It is the first time Australia's highest court has ruled on a case linked to climate change, and the decision is already calling other major mining projects into question.

Australia's coal

The Mount Pleasant mine is located near Muswellbrook in the Hunter Valley, one of Australia's main coal-mining regions. The area has a population of around 272,000 people, while the coal mines number 41, owned by 11 producers. The latest data for 2023 show that the region emitted 4.6 million tonnes of greenhouse gases, equal to 34.5 per cent of the emissions of the state of New South Wales. Mining activity is a decisive contributor to this figure.

In 2022, the New South Wales Independent Planning Commission had approved a project to double production at the Mount Pleasant mine, bringing it to around 21 million tonnes of coal per year, with operations planned until 2048. At that point, a group of residents — led by retired teachers Wendy Wales and Tony Lonergan and gathered under the community organisation Denman Aberdeen Muswellbrook Scone Healthy Environment Group (Dams Heg) — decided to take the matter to the courts to block the expansion project, citing its devastating environmental impact.

The residents' mobilisation

Initially, the New South Wales Land and Environment Court ruled in favour of MACH Energy, the company that operates the mine. The group of residents, however, did not give up and pressed on with its fight until, in 2025, the New South Wales Court of Appeal ruled in their favour.

The court ruled that the independent planning commission, when approving the mine's expansion plan, should have assessed all emissions associated with the project, including "scope 3 emissions" that occur when coal is exported and burned abroad, which would account for 98 per cent of total emissions. This represents a significant paradigm shift in the fight against climate change, as it calls for an assessment of whether a project generates emissions not only locally but also along the entire commercial chain associated with the fuel.

MACH Energy appealed against the court's ruling. Now, however, the Australian High Court has delivered a ruling that is in its own way historic, as it is the first on a case linked to climate change. By three votes to two, it rejected the coal company's appeal, establishing that the state planning commission should have assessed — and failed to assess — how to mitigate the greenhouse gas emissions that would have been generated by the mine when the coal was sold and burned abroad. As a consequence of the ruling, the mine's expansion project has been blocked.

A paradigm shift

"Today the High Court has affirmed what we have always known: we cannot extract coal, ship it overseas, watch climate change happen passively, and then pretend the consequences don't concern us and won't affect us," commented Wendy Wales, the retired science teacher who initiated the legal action. According to Johnson Legal, the law firm that represented the residents, the ruling obliges Australian governments to take responsibility for emissions generated by coal exports.

MACH Energy said it was "disappointed" and announced a new appeal, emphasising the job losses that could result from the court's ruling. Meanwhile, the ruling could soon have an impact on other mining sites as well. The independent planning commission recently approved another major project — the expansion of Hunter Valley Operations. This is the largest coal mine expansion project in the history of New South Wales, and here too, as in the case of the Mount Pleasant mine, it is estimated that 98 per cent of emissions would come from the combustion of exported coal. This could create legal difficulties in light of the new ruling.

The Minerals Council of Australia, which represents the mining sector, criticised the ruling, pointing out that "developing a coal mine in Australia is already difficult enough due to lengthy approval times, legal battles initiated by activists, and high royalties and other taxes." Environmental activists, as well as the Greens party, have pledged that the fight will continue and will extend to other extraction sites, with the aim of enshrining once and for all the principle that fossil fuel extraction cannot be artificially separated from the climate consequences of its use.