Australia’s High Court has dismissed MACH Energy’s appeal over the approval of its Mount Pleasant coal mine expansion in New South Wales.
The decision, delivered on Wednesday, 7 October, leaves the company’s challenged expansion approval invalid. The case was brought by the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, a community organisation in the Hunter Valley.
The High Court’s judgment records that the appeal was dismissed with costs. Three of the five judges supported that outcome.
What the court found
The majority found that the NSW Independent Planning Commission had failed to consider whether approval should carry conditions to minimise all greenhouse gas emissions as far as practicable, including downstream emissions.
These are known as Scope 3 emissions. In this case, they arise mainly when customers burn the mine’s coal overseas.
The judgment records that Scope 3 emissions accounted for approximately 98 per cent of the project’s estimated greenhouse gas emissions. The legal issue concerned the commission’s obligations under NSW planning law when granting consent.
The finding concerns how the project was assessed and approved. It does not establish an automatic prohibition on coal mining.
Existing operations can continue
In its response to the ruling, the NSW Government said Mount Pleasant holds a separate approval allowing operations to continue until 2032.
The government said Wednesday’s decision does not change that permission. It also said the expansion could be reconsidered and that the judgment does not prevent coal mine extensions from receiving approval.
Officials will examine the full judgment to ensure future planning decisions meet legal requirements. The government added that MACH Energy had indicated it would continue pursuing options for the project.
Company considers its next steps
According to ABC’s reporting, the proposed expansion would have almost doubled annual production and extended mining until 2048.
The planning commission approved the expansion in 2022. A community challenge subsequently reached the NSW Court of Appeal, which ruled against the approval in July 2025. MACH Energy then appealed to the High Court.
ABC reported that the company would work with regulators, governments, and local communities to understand the decision’s practical implications and pursue options for the operation’s longer-term future.
Campaigners welcome the result
In a statement released through the Climate Media Centre, community representatives welcomed the ruling and argued that it could influence fossil fuel approvals beyond Mount Pleasant.
Group president Wendy Wales said exporting coal did not remove the responsibility to consider the climate consequences of burning it. The campaigners also anticipated wider implications for other projects. Those predictions are their interpretation of the decision.
University of Melbourne lecturer Liz Hicks told ABC that the ruling primarily affects NSW projects because it turns on that state’s law. She said courts and decision-makers elsewhere would nevertheless take notice.
Trivane View
The ruling makes the assessment of downstream emissions central to this project’s approval process. Its wider significance will depend on the laws governing other developments and how courts apply them.
For readers and workers, the immediate distinction matters: the expansion appeal has failed, while existing operations retain separate approval. Future reporting should track any revised applications and the conditions proposed to address emissions.
