- The Guardian
- Issue #2190
The Hague delivered its own landmark advisory opinion, finding that fossil fuel-exporting nations bear legal responsibility under international law for the climate harm their exports cause. Photo: rawpixel (CC0) Photo: rawpixel.com (CC0)
On 13 May 2026, the High Court of Australia heard the nation’s first ever climate change case to reach our highest court – a landmark moment that will set a binding national precedent on whether Australian planning authorities are legally required to consider the local climate impacts of fossil fuel project approvals.
The case, MACH Energy Australia Pty Ltd v Denman Aberdeen Muswellbrook Scone Healthy Environment Group Inc (DAMS HEG), was brought by a grassroots Hunter Valley community group challenging the approval of a major expansion of the Mount Pleasant open-cut coal mine near Muswellbrook. The NSW Court of Appeal ruled unanimously in July 2025 that the mine’s approval was unlawful – finding that planning authorities are legally required to consider the specific local climate impacts of a project’s downstream emissions. MACH Energy has asked the High Court to overturn that ruling.
The case arrived at an extraordinary moment. Just 12 hours before the NSW Court of Appeal’s ruling, the International Court of Justice in The Hague delivered its own landmark advisory opinion, finding that fossil fuel-exporting nations bear legal responsibility under international law for the climate harm their exports cause. Australia had argued to the ICJ that it bore no such responsibility for emissions from its coal and gas exports. The ICJ rejected that argument.
That’s really important. For years, Australian governments have been using a variation of the ‘drug dealer argument’ – if we don’t sell this stuff somebody else will – as well as pretending that what people in other countries do with our fossil fuels is not Australia’s problem. The International Court of Justice has rejected that.
Four of the world’s leading climate law and science institutions have been granted leave to intervene in the High Court in support of DAMS HEG – from the Universities of Cambridge, Columbia and Melbourne, and the Union of Concerned Scientists. The case is being watched internationally as a test of whether domestic law can hold fossil fuel producers accountable for the local consequences of dangerous climate change.
The case directly affects 18-plus coal proposals in the NSW planning pipeline, and other fossil fuel developments under consideration across Australia. It will provide a foundation for other major climate cases including the Pabai Torres Strait appeal, the North West Shelf challenge, and future climate litigation across Australia and internationally.
