Melbourne, Australia’s highest court has just delivered its first-ever decision in a climate case. And it could sour the economic argument for developing new coal and gas projects in New South Wales, and possibly Australia.
After the United States and Brazil, Australia has more of these cases than anywhere else: 193 cases by the end of 2025. In 2022, the Independent Planning Commission, the body that decides on major NSW projects, approved the expansion of the mine. the NSW Court of Appeal unanimously agreed with their arguments and declared the approval invalid in July 2025 Although the community group lost in the Land and Environment Court.
This wealth of climate litigation is due to the prevalence of fossil fuel projects in Australia, coupled with lax regulation and high community engagement. Because a court can legally require governments and companies to act, in a way that community opposition or political pressure can’t, climate litigation is used. There are now thousands of these cases worldwide. It is particularly effective where government regulation is slow, weak or missing altogether. But a local community group, the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, challenged that approval in the NSW Land and Environment Court. The community group argued the planning commission had failed to ask how the mine’s emissions would worsen climate change in the Hunter region. MACH Energy appealed this decision, bringing the case to the High Court in May this year. Community groups now have a clear, High Court-endorsed basis to challenge approvals where authorities haven’t properly assessed a project’s full carbon footprint.
The group also argued the commission breached a NSW planning rule that required it to consider imposing conditions to minimise greenhouse gas emissions, including scope 3 emissions, to the “greatest extent practicable”. The court’s decision on Wednesday – in a case brought by a community group against mining company MACH Energy over a coal mine expansion – is not a unified legal declaration against fossil fuels.
