High Court Blocks Mount Pleasant Coal Mine Expansion

The High Court of Australia issued a 3-2 split judgment invalidating the approval for the expansion of the Mount Pleasant coal mine in New South Wales. The ruling establishes a binding national precedent requiring decision-makers to consider Scope 3 emissions—pollution generated when exported coal is burned overseas—and how those emissions contribute to local climate risks such as bushfires, drought, and flooding.

The court upheld a previous appeals ruling that the New South Wales Independent Planning Commission failed its legal obligations by ignoring these downstream effects. The decision halts a proposal by MACH Energy to nearly double annual output and extend the mine's operational life to 2048. The case was brought by the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, led by retired science teachers Wendy Wales and Tony Lonergan.

MACH Energy expressed disappointment but stated it will pursue options to ensure the long-term continuity of the operation. The Minerals Council of Australia warned that the ruling may force mines to determine how to reduce emissions from their export customers. While the expansion is blocked, the mine is permitted to continue current operations until 2032. The proposal must now be referred back to the New South Wales Independent Planning Commission or the NSW Land and Environment Court for a proper assessment. The ruling currently affects 17 other coal proposals in the New South Wales planning pipeline.