High Court of Australia 3:2 ruling revives Scope 3 duty in NSW consents
In MACH Energy Australia v Denman Aberdeen Muswellbrook Scone Healthy Environment Group [2026] HCA 35, the High Court of Australia held 3:2 that NSW consent authorities cannot assess resource projects on Scope 1 and 2 emissions alone.
On 7 October 2026 the High Court of Australia dismissed MACH Energy's appeal 3:2 (Gordon J, Edelman and Beech-Jones JJ; Gageler CJ and Jagot J dissenting), holding the NSW Independent Planning Commission's 2022 consent for the Mount Pleasant coal mine extension invalid. Consent authorities cannot satisfy s 4.15 of the Environmental Planning and Assessment Act 1979 (NSW) by addressing only Scope 1 and Scope 2 emissions; they must at least consider whether conditions to minimise all greenhouse gas emissions, including Scope 3, to the greatest extent practicable should be imposed, as clause 2.20(1)(c) of the State Environmental Planning Policy (Resources and Energy) 2021 contemplates. The majority also read "in the locality" as qualifying the enumerated considerations rather than the likely-impacts inquiry, declining to create a separate mandatory climate consideration; that question was left undetermined. The matter remits to the Land and Environment Court of NSW. For energy and mining clients, the operational point is that downstream emissions analysis in environmental impact documentation is no longer optional: proponents should model Scope 3 exposure and pre-empt conditions, and opponents will test whether the record shows the question was genuinely turned to.