What Happened? In 2022, Mach Energy received the greenlight to extend the life of its Mount Pleasant coal mine in the Hunter Valley until 2048.
But the Denman Aberdeen Muswellbrook Scone Healthy Environment Group argued the mine’s impact on climate change in the area was not properly considered in its approval.
The group appealed the decision in the NSW Court of Appeal and in July 2025 the court ruled the initial approval was invalid, based on the fact that the effects of climate change brought on by coal after being exported and burned were not properly considered.
Mach fights back: Mach Energy subsequently appealed that verdict in the High Court.
The matter’s only hearing was held on Wednesday and a written judgment from the High Court will follow in the coming weeks or months.
The verdict could reshape the way fossil fuel projects are approved in NSW and potentially nationally.
Emissions: When approving a project like a coal mine in NSW the Independent Planning Commission (IPC) has to consider the three types of emissions that will come from it:
Scope one - Pollution created by machinery used to dig coal
Scope two - Pollution from the electricity used to power the facility
Scope three - Pollution from the coal exported from the mine and burned
Ninety-eight percent of the mine’s emissions are scope three, and this is the focus of the case.
Measures: The IPC approved the mine with conditions in place to minimise the effects of scope one and two emissions.
When it came to scope three it said the effects would be dealt with through other countries' climate change policies.
Community’s case: This is not good enough for locals, who argue the approval should have considered how higher temperatures and increased fire risk, caused by the effects of global warming, would have on the Hunter Valley.
Special rules: The community group also argued another planning law was not properly considered by the IPC.
The law says that the IPC needs to look at making the mine minimise all of its emissions, which includes the pollution from the coal being burned overseas.
The IPC only made the mine minimise its emissions on site (two percent of the total), which locals say contradicts this rule.
Miners argument: Mach Energy argued the planning commission did its job by saying international climate change policies, like the Paris Agreement, were adequate in handling the emissions caused by the coal from its mine being burned.
Significance: President of the community group, Wendy Wales, said “planning authorities across New South Wales are now on notice that the climate impacts of their decisions are not someone else's problem. That's not nothing. But we need to win, for the communities that are already living through the floods and fires and droughts that nobody is being held accountable for”.
Thumbnail: Zoe Lonergan