The New South Wales Court of Appeal, which oversees litigation in Australia's main thermal coal producing region, has blocked the extension of MACH Energy's 10mn t/yr run-of-mine (ROM) Mount Pleasant coal mine.

The court's landmark decision on 24 July came in a case lodged against the Australian producer by an environmental group — the Denman, Aberdeen, Muswellbrook and Scone Health Environment Group.

The court decided that the state's Independent Planning Commission (IDP) had made a procedural error when evaluating MACH Energy's application to extend the life of the Mount Pleasant mine by 22 years from 2026 to 2048, and increase its ROM limit to 21mn t/yr.

The IDP needed to consider mine consent conditions to minimise Mount Pleasant's scope 3 CO2 equivalent (CO2e) emissions — stemming from coal use — and the specific impact it would have on the local climate, the court found.

The appeals court has sent the case back to the New South Wales Land and Environment court to either declare the consent invalid or add additional conditions to it.

MACH Energy will review the judgement and explore all avenues to ensure continuity and certainty for the local community, it said in a statement on 25 July.

The Mount Pleasant mine was set to produce 12mn t of scope 1 CO2e emissions, 2.2mn t of scope 2 CO2e emissions, and 860mn t of scope 3 CO2e emission for the extension period of 22 years, according to a 2021 environmental impact assessment.

For the July 2023-June 2024 fiscal year, the Mount Pleasant mine reported covered scope 1 emissions of 196,934t of CO2e under the safeguard mechanism, just below its 199,238t CO2e baseline. It earned 2,304 safeguard mechanism credits (SMCs) as a result.

The Court of Appeal's decision may force a change to the state's planning process. Currently, state regulators do consider the environmental impacts of developments when making mine approval decisions but mainly focus on pollution and biodiversity.

The court's ruling indicates that regulators may need to consider the climate impacts of projects with high scope 3 emissions going forward.

The state government acknowledges the decision but won't further comment at this time, as the case has been forwarded to the Land and Environment Court, New South Wales' minister for planning and public spaces Paul Sculley told Argus on 25 July.

MACH Energy has faced legal challenges to its Mount Pleasant mine expansion plans before. An Australian legal non-profit, the Environmental Defenders Office, challenged the project in 2022, over the impact it could have on a species of legless lizards.

By Avinash Govind