In a landmark ruling, the High Court of Australia has dismissed an appeal by MACH Energy, ruling that planning authorities are legally required to consider the global climate impacts of burning Australian coal overseas before approving mining projects.
The ruling in favour of the Denman Aberdeen Muswellbrook Scone Healthy Environment Group (DAMS HEG), a grassroots Hunter Valley community organisation, marks the nation’s first climate change case to reach Australia’s apex court.
The decision upholds a NSW Court of Appeal finding that the Independent Planning Commission failed its mandatory legal obligations when approving the expansion of MACH Energy’s Mount Pleasant open-cut coal mine near Muswellbrook in 2022.
The proposed expansion aimed to nearly double annual production, extracting 444 million tonnes of coal through to 2048 and generating over 870 million tonnes of greenhouse gas emissions, 98 per cent of which would occur overseas as Scope 3 emissions.
Three of the five High Court judges found that decision-makers must account for downstream emissions and their local consequences, including intensified droughts, extreme heat, and bushfires across Australian communities.
This sets a binding national precedent across the NSW planning system, requiring decision-makers to consider the impact of climate change associated with a project’s emissions.
The ruling directly impacts 17 coal proposals currently in the NSW planning pipeline and creates a legal framework expected to influence project assessments nationwide.
The approval for the Mount Pleasant expansion remains invalid and will return to the Land and Environment Court or Independent Planning Commission for reassessment.
DAMS HEG President Wendy Wales welcomed the decision after a four-year legal battle.
“The High Court has said what we have always known: we cannot dig up coal, ship it overseas, watch it drive climate change, and then pretend the consequences have nothing to do with us,” Wales said.
However, industry groups warned the precedent threatens foreign investment. Critics argue the judgment heightens sovereign risk for international trading partners, compounding long approval timelines and legal uncertainty for major resource projects.
Tania Constable, CEO of the Minerals Council for Australia, warned the decision is a blow to global demand for Australia’s coal.
“This decision sends a very negative signal to Australia’s trade and investment partners about sovereign risk in this market,” Constable said.
“Australian resource companies should not be forced into a situation where well-funded legal attacks over a number of years require a High Court appeal. These legal challenges seek to game the legal system by creating uncertainty and delay without ever having to pay costs.”