Australia’s first climate change case to be considered by the High Court will be heard next month, with significant implications for the Upper Hunter.
The case, MACH Energy Australia versus Denman, Aberdeen Muswellbrook Scone Healthy Environment Group (DAMSHEG), will be heard by the High Court of Australia from May 13. It follows a landmark NSW Court of Appeal ruling last year that overturned planning approval for the expansion of the Mount Pleasant coal mine near Muswellbrook.
The Mount Pleasant Optimisation Project would have doubled coal production to 21 million tonnes a year until 2048. While the project was approved by the NSW Independent Planning Commission in 2022, that decision was set aside in July 2025 after the Court of Appeal found planners failed to consider local climate impacts when assessing the expansion.
MACH Energy has now challenged that finding, arguing the original approval should be reinstated. The High Court will consider whether environmental impact assessments must account for downstream greenhouse gas emissions, and whether those emissions can be understood as causing harm “in the locality” of the mine.
