The High Court of Australia has affirmed the Supreme Court of New South Wales’ (NSW) decision to overturn the Independent Planning Commission’s (IPC) approval of MACH Energy’s Mt Pleasant coal mine extension over climate concerns.
But it upheld the ruling on narrower grounds than the lower court, in a 7 October decision.
In July 2025, the Supreme Court overturned the IPC’s decision because the Commission failed to impose conditions to reduce Mt Pleasant’s downstream greenhouse gas emissions, and failed to consider the impact of climate change on communities near the mine.
The High Court affirmed the Supreme Court’s ruling because the IPC needed to impose conditions to reduce Mt Pleasant’s downstream emissions to the greatest extent practicable, it said in its judgement. However, the IPC did not need to consider the local impact of climate change in its approval process, it added.
The Commission needs to consider the local environmental impact of projects when assessing them, the High Court found. “[But courts] cannot and should not address … whether the impact of climate change is capable of being [a local] environmental impact, [as legally defined],” it said.
“While [environmental] impacts may, and often will, include [local impacts], their identification is a matter for the Commission, as the consent authority,” it added.
MACH Energy accepts the High Court’s decision and will review its judgement to understand its impact on future project assessments and approvals, the company said on 7 October. “MACH Energy remains committed to operating responsibly within whatever legal framework the NSW Parliament and the courts establish,” the company added.
NSW Greens Planning Spokesperson Sue Higginson has suggested that the High Court’s ruling could impact the IPC’s recent approval of Hunter Valley Operations’ (HVO) application to extend the life of its two coal mines by 12 years and 19 years, respectively.
But the IPC has imposed conditions to limit HVO’s downstream emissions. The company can only sell coal from its extension project to markets with greenhouse gas emission-reduction policies consistent with the Paris Climate Accords, the IPC said in its approval decision.
The High Court’s decision does not mean that coal mine extensions cannot be approved, NSW Natural Resources Minister Courtney Houssos said. “[Coal] will continue to play an important role in NSW for decades to come,” Houssos added.
By Avinash Govind