The High Court blocks a major NSW coal mine extension over its emissions, in a ruling that could reopen other approvals
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.
DailyDrop Australia edition No. 3 · Morning · WED., OCT. 7, 2026