The High Court found the NSW Independent Planning Commission failed to consider how to mitigate the greenhouse gas emissions that would be generated when the mine's coal is sold and burnt overseas – known as Scope 3 emissions. The Mount Pleasant expansion would have doubled output to 21 million tonnes per annum until 2048, with 98% of projected emissions falling into this category.
Wendy Wales, president of the Denman Aberdeen Muswellbrook Scone Healthy Environment Group (Dams Heg), the community group that brought the original case, said the ruling acknowledged what residents had long argued. "We cannot dig up coal, ship it overseas, watch it drive climate change, and then pretend the consequences have nothing to do with us and won't be felt by us," she said. "The droughts, the bushfires, the floods – are directly connected to greenhouse gases, and massive fossil fuel projects like Mt Pleasant Optimisation simply 'add fuel to the fire'."
Wales said the decision was a recognition that many Australians had "already suffered extreme weather devastation" and that "we must live within nature's limits". The community group pursued the case through the courts for more than four years, after initially losing in the Land and Environment Court before succeeding in the NSW Court of Appeal last year.
Advocates say the ruling sets a binding national precedent for fossil fuel projects in New South Wales and could have broader implications for how climate impacts are weighed in project approvals across Australia. Comment has been sought from MACH Energy.