On October 7 the High Court dismissed MACH Energy's appeal over the Mount Pleasant coal mine extension in the Hunter Valley. A majority of three, Justices Gordon, Edelman and Beech-Jones, held that the NSW Independent Planning Commission had not considered whether to impose conditions to minimise scope 3 emissions, the gases released when the coal is burned. Reports put scope 3 at about 98 per cent of the project's emissions. Chief Justice Gageler and Justice Jagot dissented on that point. All five agreed the commission had met its duty to consider the likely environmental impacts and rejected the Court of Appeal's reasoning on that duty. The court did not decide whether climate change counts as an impact in the locality of a development. The matter returns to the commission. The Court of Appeal had invalidated the approval in July 2025; the High Court heard the case in May. Campaigners celebrated, miners warned of lost investment and lawyers said it could reopen other approvals.
Australia's coal export approvals have never had to confront the climate effect of burning the coal overseas. This is the first High Court ruling to make a decision-maker look at it. The scale is large because most of a coal mine's emissions are released by the customers.
If you work in coal in the Hunter or hold shares in a miner, expect re-assessments and delays at other projects. For everyone else the effect is slow: approvals now require a closer look at emissions conditions.
The court enforced the law as written. A decision-maker must consider whether to limit the climate harm of the project it approves, and has to say so.
The ruling invites a wave of litigation against projects that were legally approved and puts jobs and investment at risk, and it leaves the actual test unclear because the court avoided the bigger question.
Do not mistake the ruling for a ban. Watch the commission's re-assessment of Mount Pleasant and the first challenge to another mine, because those will show how far the principle travels. The government's own gas and coal decisions are the political question this leaves open.
ABC News · SBS · Sydney Morning Herald · The Age · The Guardian · Australian Financial Review · 98.1 Power FM · Mining.com.au · Monash Lens commentary (Oct. 7) · Judgment text not read; split of judges as reported
The High Court blocks a major NSW coal mine extension over its emissions, in a ruling that could reopen other approvals
By a 3–2 majority, the court held the planning commission failed to consider conditions on the mine's downstream emissions. Climate groups cheered, miners warned of lost investment and one lawyer called it a Pandora's box.
The High Court of Australia dismissed an appeal by MACH Energy on Wednesday, ending the company's attempt to restore approval for a 22-year extension of the Mount Pleasant coal mine in the Hunter Valley. The ABC, SBS, the Sydney Morning Herald, The Age, the Guardian and the Australian Financial Review all reported the decision, which the ABC described as a massive shake-up for coal and gas and which is the first ruling from the nation's highest court on how far a planning decision must look at climate effects. Three of the five judges, Justices Gordon, Edelman and Beech-Jones, found that the NSW Independent Planning Commission had not discharged its statutory obligations. The commission imposed conditions on the mine's own emissions, which are a small share of the total, but did not consider whether to impose conditions to minimise the so-called scope 3 emissions, the greenhouse gases released when the coal is burned overseas. Reports put that downstream share at about 98 per cent of the project's total. Chief Justice Gageler and Justice Jagot dissented on that point.
The case now goes back to the commission to be assessed again in accordance with the law. The decision is narrower than some headlines suggest. All five judges agreed on a separate issue, that the commission had met its duty to consider the likely environmental impacts of the project, and they rejected the NSW Court of Appeal's reasoning on that duty. The court did not decide the larger question of whether climate change is an environmental impact in the locality of a development, which commentators say was left open. The challenge was brought by a local community group, the Denman Aberdeen Muswellbrook Scone Healthy Environment Group. The NSW Court of Appeal had invalidated the approval in July 2025, and the High Court agreed to hear the appeal in December and heard it in May. Reports also say a separate, later approval allows the mine to keep operating to about 2032, which was not part of the appeal; we have not confirmed that against planning records.
Reaction split quickly. SBS reported celebrations among campaigners, one of whom said the planning process had been exposed for the sham it is. A NSW MP told the Guardian that lawyers should be running to the courts to stop coal approvals. The Herald quoted a legal view that the ruling is a Pandora's box that could reopen coal mine approval cases. In the other direction, the AFR reported that miners warn the landmark ruling puts investment at risk, and ran a commentary urging calm because the High Court's coal mine judges are no climate activists. The Age said a legal reckoning has arrived for Australian mining. The decision does not stop Mount Pleasant or any other mine. It requires that decision-makers look at downstream emissions before approving them, and it leaves the political question, whether to approve the coal anyway, with the government.