Australia's Highest Court Just Killed a Coal Project

Australia's highest court has killed a Coal Project in a landmark climate ruling, finding that planners unlawfully ignored the emissions released when exported coal is burned overseas. The High Court of Australia dismissed an appeal by MACH Energy in a 3-2 split decision in October 2026, leaving invalid the 2022 approval of the Mount Pleasant expansion. It was the first climate case the country's top court had ever decided, according to the Guardian.

The pit sits in the Hunter Valley of New South Wales, and the expansion would have doubled its output to 21 million tonnes a year and kept it running until 2048. Almost all of the project's projected greenhouse gases — 98 per cent — would have come from burning the exported coal overseas rather than from digging it up. The case was brought by a community group of local teachers, farmers and townsfolk, the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, after state planners signed off on the project in 2022. The group's president, Wendy Wales, said the decision affirmed what residents had argued all along: coal dug up locally and burned overseas still drives the droughts, fires and floods felt back home.

A four-year fight over who counts the smoke

The dispute stretches back to the mine's original 1999 consent and sharpened after the operator acquired the site in 2016 and 2018. The state's Independent Planning Commission approved the optimisation project in September 2022 with conditions. The residents' group challenged that approval, arguing the commission had failed to consider conditions that would minimise greenhouse gas emissions to the greatest extent practicable, as the state's resources planning policy requires. In July 2025 the NSW Court of Appeal unanimously agreed and sent the matter back to the NSW Land and Environment Court. The operator appealed to the top court — and lost. It is the first time the country's top judges have struck down a Coal Project on climate grounds.

At the heart of the case was a chain of causation the industry has long tried to break: the operation digs the coal, someone else burns it, so the pollution is someone else's problem. A majority of the court rejected that split, finding the commission was required to weigh conditions aimed at minimising emissions from coal burned overseas, and had not done so. The group's principal lawyer described the decision as confirmation that planning authorities cannot ignore the chain of causation from a project's emissions.

Twelve days later, the state rewrote the rules

Less than two weeks after the ruling, the state government announced it would introduce special legislation letting the operator lift output at the site by 4 million tonnes, to 16.5 million tonnes a year until 2032 — an increase of 32 per cent. Premier Chris Minns said the bill was necessary because jobs were at risk before Christmas. "There are 400 jobs on the line that will go before Christmas without this intervention," Minns said, according to Guardian Australia.

The residents' group called the move legislative overreach. State Greens MP Sue Higginson described the bill as bypassing both the planning process and the court's ruling. An activist alliance spokeswoman, Georgina Woods, said jobs were never at risk because the operation already holds a separate permit to produce 12.5 million tonnes a year for six more years. The group's law firm, Johnson Legal, warned that special rules for a single site could look like laws written to benefit one owner.

The matter now returns to the lower court while the bill heads to parliament — a collision that will test whether courtroom climate wins can survive politics. For young Australians, the stakes are concrete: the official climate risk assessment ranks the state among the areas facing the fastest-rising climate hazards, from worsening drought and bushfire to flood. The ruling also lands as Australia prepares to preside over global climate negotiations, with Pacific nations holding the 1.5C limit as a survival line. Greenpeace Australia Pacific called the decision "a victory for communities that bear the brunt of the storms, bushfires and extreme weather fuelled by Australian fossil fuel corporations," its head of climate and energy Joe Rafalowicz said in a statement.

The judgment sets a precedent: any future Coal Project in the state must now weigh the full climate cost, including the smoke released overseas. Similar fights are moving through courts on other continents — the United States Supreme Court heard arguments in October 2026 in a case that could decide whether dozens of state-level climate lawsuits against oil companies survive. The valley's retired science teachers just proved a small community group can force that question and win. The ruling also complicates a separate, far larger coal extension approved weeks earlier, which now looks legally fragile; and on the other side of the resource debate, Ghana is moving to end raw mineral exports.