Mount Pleasant ruling: 98% of emissions were ignored, now approvals face review

On 7 October 2026, the High Court of Australia dismissed MACH Energy's appeal against the Mount Pleasant coal mine expansion near Muswellbrook, New South Wales. Three of five judges found the NSW Independent Planning Commission had failed to consider imposing conditions to minimise to the greatest extent practicable all greenhouse gas emissions — specifically Scope 3 emissions — as required by cl 2.20(1)(c) of the Resources SEPP and s 4.15(1)(a)(i) of the EPA Act.

The ruling upheld the NSW Court of Appeal decision that invalidated the project's planning approval. The Mount Pleasant mine is an open-cut coalmine approved for expansion by NSW planning authorities in 2022 before being halted through a community-led court battle.

The statutory failure matters because of scale. Scope 3 emissions — those released when coal is burned, including overseas — make up 98% of the development's projected impacts. The extension would add roughly twice Australia's total annual greenhouse gas emissions to the atmosphere.

It is a finding that planning authorities must assess downstream emissions when approving coal, gas and oil projects. The distinction is legal, not rhetorical: the Commission failed to consider conditions to minimise those emissions, and that failure invalidated the approval.

The implications extend beyond Mount Pleasant. The Greens say the IPC's recent HVO coal approval, also 98% Scope 3 emissions, is likely to face significant legal difficulty following this decision. The case is expected to have national implications for how fossil fuel project approvals take global emissions and local climate change impacts into account.

For now, the legal position is clear: planning authorities cannot ignore the emissions that happen when fossil fuels are burned overseas. The Mount Pleasant approval was invalidated because the Commission failed to consider them. Every other pending fossil fuel approval now faces the same statutory requirement.

- [abc.net.au](https://www.abc.net.au/news/2026-10-07/mount-pleasant-coal-mine-high-court-ruling/107233650) - [rnz.co.nz](https://www.rnz.co.nz/news/world/1782134/australian-high-court-rules-in-favour-of-climate-group-in-hunter-valley-coalmine-case) - [news24.com.au](https://www.news24.com.au/politics/australian-politics/high-court-delivers-landmark-fossil-fuels-ruling-with-major-implications-for-future-mining-projects/news-story/ab8955a99b1fdd7b4c39d2428a8b33cc) - [miragenews.com](https://www.miragenews.com/high-court-decision-nail-in-coffin-for-new-coal-1755940/)