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. This High Court judgement is timely – Australia is co-hosting an international pre-COP31 climate summit in the Pacific this week and is facing renewed pressure from Pacific leaders over fossil fuel projects. The court’s decision on Wednesday – in a case brought by a community group against mining company MACH Energy over a coalmine expansion – is not a unified legal declaration against fossil fuels. But this restrained, technical judgement quietly sets a new standard for coal and gas projects in the state – and potentially across the country. It means planning authorities must consider the whole carbon footprint of these projects, including the emissions produced by customers burning these fossil fuels overseas. Although the decision concerns one specific coal mine – MACH Energy’s Mount Pleasant coal mine in NSW – it directly affects the 17 other coal proposals currently in the state’s planning pipeline. It could also provide a legal blueprint for how courts across the country handle future cases against fossil fuel projects. Climate litigation involves taking governments or companies – and occasionally individuals – to court in a bid to hold them responsible for climate harms. There are now thousands of these cases worldwide. After the United States and Brazil, Australia has more of these cases than anywhere else: 193 cases by the end of 2025. This wealth of climate litigation is due to the prevalence of fossil fuel projects in Australia, coupled with lax regulation and high community engagement. Climate litigation is used because a court can legally require governments and companies to act, in a way that community opposition or political pressure can’t. It is particularly effective where government regulation is slow, weak or missing altogether. Read more: Climate litigation is on the rise around the world and Australia is at the head of the pack
The Mount Pleasant open-cut coal mine sits near Muswellbrook, in NSW’s Hunter Valley. It was originally approved to run until December 2026, digging up to 10. 5 million tonnes of coal each year. In 2021, the mine’s owner, MACH Energy, sought to extend its life by 22 years, and double its output to 21 million tonnes a year until 2048. Most of the mine’s climate footprint does not come from the mine itself, but from the burning of the coal it produces. The vast majority of its emissions are classified as “scope 3” – this includes the emissions produced when the mine’s coal is burned overseas.