---
title: "Australia’s High Court Makes New Coal Mines Harder to Approve, Not Impossible"
description: "The 3-2 ruling makes New South Wales planners weigh curbs on emissions from exported coal but leaves federal approvals untouched"
author: "rews special report"
published: 2026-10-07T02:18:53.701Z
modified: 2026-10-07T11:07:42Z
url: https://rews.cc/a/high-court-blocks-mount-pleasant-coal-expansion-over-emissio-eeb22a
language: en
type: special report
tags: ["climate", "law", "coal", "australia", "supreme-court", "asia", "world"]
publisher: "Rews (https://rews.cc)"
---

# Australia’s High Court Makes New Coal Mines Harder to Approve, Not Impossible

*The 3-2 ruling makes New South Wales planners weigh curbs on emissions from exported coal but leaves federal approvals untouched*

Special report · By rews special report · October 7, 2026 · https://rews.cc/a/high-court-blocks-mount-pleasant-coal-expansion-over-emissio-eeb22a

## In brief

- Australia’s High Court ruled 3-2 on Oct. 7 that NSW planners unlawfully approved the Mount Pleasant coal mine expansion
- All five judges found the general impact-assessment duty was met, and the court did not order the expansion refused
- The majority said planners failed to consider conditions on about 860 million tonnes of emissions from coal burned abroad
- The mine can run to 2032 under an August approval, while the expansion returns to the Land and Environment Court
- Federal approvals are not directly affected, and the HVO mine approved Sept. 30 already carries scope 3 conditions

Australia’s High Court ruled 3-2 on Wednesday that planners in New South Wales acted unlawfully when they approved a 22-year expansion of the Mount Pleasant coal mine without considering whether to curb the roughly 860 million tonnes of greenhouse gases its coal would release in other countries’ power stations.

It was the first climate case to reach the court, and the holding is narrower than much of the first day’s coverage suggested. All five judges found that the state’s Independent Planning Commission had met its general duty to weigh the project’s likely environmental impacts, [the Hunter radio station 2NM reported](https://www.2nm.com.au/local-news/high-court-dismisses-mach-energy-appeal-over-mount-pleasant-coal-mine-extension/). The majority ruled against the mine’s owner, MACH Energy, on a different point. The commission never asked whether to attach conditions to cut the 98 percent of the project’s emissions that would occur overseas, and a state mining policy obliges it to ask. The court did not decide that the expansion should be refused, or that any particular condition must be imposed.

Read against the record, the ruling will not by itself stop new coal or gas projects in Australia, which exported 363 million tonnes of coal in 2024, second only to Indonesia’s 555 million, [according to the International Energy Agency](https://www.iea.org/reports/coal-2025/trade). It binds consent authorities in one state to a procedural step. It leaves federal approvals alone. And it landed a week after the same commission showed how a project can clear that step, approving the Hunter Valley Operations extension owned by Yancoal and Glencore on Sept. 30 with a plan for overseas emissions attached. What it changes is the price of getting an approval wrong. Every pending coal decision in New South Wales is now open to the challenge that sank Mount Pleasant’s.

## What the court decided

MACH Energy, which is owned by Indonesia’s Salim Group, wanted to double output at Mount Pleasant, near Muswellbrook in the Upper Hunter, from 10.5 million to 21 million tonnes a year and keep mining until December 2048. The commission [approved the plan on Sept. 6, 2022](https://www.ipcn.nsw.gov.au/news/2022/09/mt-pleasant), allowing about 444 million tonnes of run-of-mine coal over the life of the mine. Its published summary said the project’s emissions “have been adequately estimated and are permissible in the context of the current climate change policy framework.”

The project’s total footprint was estimated at 876.07 million tonnes of greenhouse gases, [RenewEconomy reported](https://reneweconomy.com.au/high-court-rejects-major-coal-mine-extension-in-landmark-decision-based-on-climate-change-impacts/), and all but about 17 million tonnes would come from customers burning the thermal coal, mostly abroad. The judgment puts the overseas share at about 860 million tonnes, which is why figures from 860 million to “more than 870 million” have been cited for the same project. Those emissions do not appear in Australia’s national greenhouse inventory, [RNZ reported](https://rnz.co.nz/news/world/1782134/australian-high-court-rules-in-favour-of-climate-group-in-hunter-valley-coalmine-case). Justice James Edelman cited an estimate by Penny Sackett, a former chief scientist of Australia, that the expansion would rank among the 650 largest emitting projects in the world, [the Australian Associated Press reported](https://canberratimes.com.au/story/9364134/high-court-ruling-in-coal-court-case-spooks-miners).

The commission set conditions on the roughly 2 percent of emissions produced at the mine site and none on the rest. Clause 2.20 of the state’s Resources and Energy planning policy requires a consent authority to consider imposing conditions aimed at keeping greenhouse gas emissions down “to the greatest extent practicable.” Justice Edelman wrote that the commission went wrong “by focusing only upon two per cent of the project’s emissions,” and that it “was distracted by the accounting concepts of the scopes,” according to [a digest of the reasons](https://www.johnsonlegal.au/the-latest/mach-energy-v-denman-high-court-of-australia) published by Johnson Legal, the firm that represented the residents.

Justice Michelle Gordon went at the accounting argument directly. Scopes 1, 2 and 3 are categories used in corporate and national bookkeeping, she wrote, and “there is no reference to emissions ‘scopes’ in the UNFCCC, the Paris Agreement, or any other international law.” She added one more sentence.

> The impact of greenhouse gas emissions is the same, regardless of how they are categorised.
>
> — Michelle Gordon, High Court justice, in the majority reasons, [johnsonlegal.au](https://www.johnsonlegal.au/the-latest/mach-energy-v-denman-high-court-of-australia)

Justice Robert Beech-Jones joined them. Chief Justice Stephen Gageler and Justice Jayne Jagot dissented, finding that the commission had dealt with overseas emissions when it observed that most countries had committed under the Paris Agreement to cut their own, [Al Jazeera reported](https://aljazeera.com/news/2026/10/7/australia-top-court-rules-against-coal-mine-expansion-citing-climate-harm). The reasons are posted on [the High Court’s case page](https://www.hcourt.gov.au/cases-and-judgments/judgments/judgments-1998-current/mach-energy-australia-pty-ltd-v-denman-aberdeen-muswellbrook-scone-healthy-environment-group-inc) as MACH Energy Australia Pty Ltd v Denman Aberdeen Muswellbrook Scone Healthy Environment Group Inc \[2026\] HCA 35.

Some first-day accounts, including [the campaigners’ own news release](https://newshub.medianet.com.au/2026/10/high-court-rules-in-favour-of-hunter-valley-community-landmark-climate-ruling-will-reshape-fossil-fuel-approvals-across-australia/175259), described the High Court as upholding the state Court of Appeal’s finding that the commission breached Section 4.15 of the planning act by failing to weigh local climate harm from the exported coal. The reasons as 2NM reported them say otherwise. The High Court rejected the appeals court’s view that local climate impacts were the focus of that duty and left open whether climate change is an impact “in the locality” at all. The distinction decides what comes next. A duty to consider conditions is far easier for a planning body to discharge than a duty to trace a mine’s share of global emissions to bushfires and floods in the Upper Hunter.

## The people who sued

The case was brought by the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, led by Wendy Wales, its president, and Tony Lonergan, its treasurer, both retired science teachers. They took it through three levels of court over four years, [the Newcastle Herald reported](https://www.newcastleherald.com.au/story/9364141/high-court-blocks-mount-pleasant-coal-mine-expansion-in-landmark-ruling/). Mr. Lonergan said he and Ms. Wales share seven grandchildren. “We did this for them,” he said. Ms. Wales said the court had confirmed that “we cannot dig up coal, ship it overseas, watch it drive climate change” and then pretend the consequences were someone else’s. She described to AAP what had happened to her town.

> We have experienced the change from a country town with a mine over the hill, to a town that is now encircled by mines
>
> — Wendy Wales, president of the Denman Aberdeen Muswellbrook Scone Healthy Environment Group, [canberratimes.com.au](https://canberratimes.com.au/story/9364134/high-court-ruling-in-coal-court-case-spooks-miners)

The ruling does not close Mount Pleasant. The mine’s existing consent was due to run out in December, [Reuters reported](https://www.timeslive.co.za/news/world/2026-10-07-australian-high-court-blocks-coal-mine-in-climate-case/), but in August the state government granted a separate approval that lets it operate until the end of 2032 with a slight increase in production. The mine employs about 500 full-time-equivalent workers, according to AAP. What the ruling puts in doubt is the long tail: 406 million tonnes of additional coal and 16 years of mining after 2032.

MACH said it was “disappointed” but accepted the decision and would “continue to actively pursue all available options to ensure the long-term continuity of the Mount Pleasant operation.” Courtney Houssos, the state’s minister for natural resources, said the ruling “does not mean the expansion cannot be reconsidered or that coal mine extensions cannot be approved.”

## The earlier cases

The words that decided the case are almost two decades old. The state’s mining policy has directed consent authorities since 2007 to consider conditions that minimize greenhouse gas emissions, and a neighboring clause says the assessment includes “downstream emissions,” [the law firm Clayton Utz noted in 2019](https://www.claytonutz.com/insights/2019/october/nsw-government-excludes-scope-3-emissions-from-mining-assessment). On Feb. 8, 2019, Brian Preston, chief judge of the Land and Environment Court, [refused Gloucester Resources’ Rocky Hill mine](https://www.abc.net.au/news/2019-02-08/rocky-hill-mine-plans-qaushed-in-nsw-court/10792902), counting the coal’s downstream emissions among several reasons and finding that a new mine was poorly timed when deep emissions cuts were needed. The commission refused the Bylong coal project that September on similar reasoning.

The Coalition government of Premier Gladys Berejiklian answered with the Territorial Limits Bill on Oct. 24, 2019. It would have barred consent conditions aimed at impacts outside Australia and struck the words “including downstream emissions” from the policy. An upper house committee [recommended in March 2020](https://reneweconomy.com.au/nsw-committee-rejects-move-to-protect-coal-mines-from-downstream-emissions-70545/) that it not pass in its current form. It never did, and the duty carried into the 2021 Resources and Energy policy as Clause 2.20, the provision the High Court applied on Wednesday.

The courts have also shown what a decision that survives review looks like. In October 2021, Chief Judge Preston rejected a farmers’ challenge to Santos’s Narrabri gas project, finding the commission had considered limits on the emissions from burning the gas and acted reasonably in declining to impose them, [ABC News reported](https://www.abc.net.au/news/2021-10-18/court-rejects-appeal-against-approval-of-narrabri-gas-project/100546832). He gave this reason.

> Santos was not shown to have any particular relationship with or control over any end user
>
> — Brian Preston, chief judge of the Land and Environment Court of New South Wales, in the 2021 Narrabri gas ruling, [abc.net.au](https://www.abc.net.au/news/2021-10-18/court-rejects-appeal-against-approval-of-narrabri-gas-project/100546832)

In Queensland, Fleur Kingham, president of the Land Court, [recommended on Nov. 25, 2022](https://www.herbertsmithfreehills.com/notes/environmentaustralia/2022-11/qld-land-court-recommends-refusal-of-thermal-coal-mine-on-climate-change-and-human-rights-grounds) that Waratah Coal’s proposed thermal coal mine in the Galilee Basin be refused, citing human rights and the 1.58 billion tonnes of CO2 its coal would release from 2029 to 2051. She rejected the company’s argument that blocking the mine would raise emissions because lower-quality coal would replace it, finding the likely substitute was other high-rank coal with similar emissions.

Federal law has gone the other way. In May 2024, the Full Federal Court [held](https://www.judgments.fedcourt.gov.au/judgments/Judgments/fca/full/2024/2024fcafc0056) that the environment minister did not have to assess climate harm from two coal mine extensions in New South Wales under national law. One of them was Mount Pleasant. Tanya Plibersek, then the minister, [later approved it](https://envirojustice.org.au/press-release/plibersek-approves-huge-expansions-to-coal-mines/) along with two others.

The residents’ turn came on July 24, 2025, when the state Court of Appeal unanimously voided the commission’s approval, one day after the International Court of Justice issued its advisory opinion on states’ climate obligations. Justice Gordon cited that opinion in a footnote this week. Elaine Johnson, a lawyer who represented the residents, posted about the appeals court’s ruling that day.

> ‘Significant legal breakthrough’ as NSW court blocks state’s largest coal expansion over emissions
>
> So proud to have represented Upper Hunter residents in this groundbreaking climate case!
>
> — **Elaine Johnson** @Elaine\_EnvLaw on X · [July 24, 2025](https://x.com/Elaine_EnvLaw/status/1948340994786869549)

## The case against

Angus Taylor, the federal opposition leader, and Matt Canavan, the Nationals leader, called the ruling “absurd” in a joint statement, arguing that Hunter miners should not answer for power stations in Japan, South Korea and India. They want the state planning act amended so that overseas emissions from exported resources are not a consideration, and federal legislation if New South Wales will not act. Tania Constable, chief executive of the Minerals Council of Australia, said the decision “sends a very negative signal” about sovereign risk. The New South Wales Minerals Council called the case “activist lawfare.”

Aaron Morey, chief executive of Western Australia’s Chamber of Minerals and Energy, said the decision created “fresh uncertainty” for the state’s liquefied natural gas industry and would push investment toward competing countries, many with weaker environmental and safety standards, Reuters reported. [Aaron Patrick, writing in The Nightly](https://thenightly.com.au/politics/aaron-patrick-the-high-courts-climate-intervention-could-drive-voters-to-the-right-c-22981415), argued that the court had made a decision that “shifts the climate-change burden back to Australia” and might push cost-conscious voters to the right.

The dissent gives the critics their firmest legal footing. Under Paris Agreement accounting, emissions belong to the country where fuel is burned, and Chief Justice Gageler and Justice Jagot found the commission had dealt with overseas emissions by pointing to importing countries’ pledges. The majority answered that who counts an emission is a separate question from whether it can be reduced, and that answer now binds every consent authority in the state. Mr. Taylor and Mr. Canavan said in their statement that the decision “turns on the wording of NSW planning law,” the Brisbane Times reported. Their quarrel is with the statute, then, not with how the court read it.

The investment-flight argument is harder to test, and this court did not try. It is a form of the market-substitution claim: if Australia does not supply the coal or gas, someone else will. The Queensland Land Court weighed expert evidence on a version of that claim in 2022 and found that the coal most likely to fill the gap was coal with similar emissions, which undercuts the industry’s contention that blocking a mine raises global emissions. Whether refusing one mine lowers world emissions, or simply moves production elsewhere, is a question Wednesday’s judgment does not ask planners to answer.

The sovereign-risk warning sits awkwardly with the approvals record. The Minns government has approved 14 coal projects since March 2023, RenewEconomy reported, and the commission approved HVO, which the Climate Council calls the state’s biggest coal project, a week before the ruling. The federal government’s own forecasts attribute the expected decline in coal exports to demand, not courts. The Department of Industry, Science and Resources [projects in its September quarterly](https://www.industry.gov.au/publications/resources-and-energy-quarterly-september-2026) that thermal coal exports will fall from 209 million tonnes in 2025 to 199 million in 2031 as importers prioritize decarbonization and domestic supply, and that earnings will drop from A$31 billion in 2026-27 to A$24 billion in 2030-31 in real terms.

Kate Owens of Sydney Law School described the ruling to RenewEconomy as “very meaningful” but “quite precise.” The duty, she said, is to give conditions proper consideration, not to impose them.

> The Court has not said that scope 3 conditions must ultimately be imposed.
>
> — Kate Owens, Sydney Law School, [reneweconomy.com.au](https://reneweconomy.com.au/high-court-rejects-major-coal-mine-extension-in-landmark-decision-based-on-climate-change-impacts/)

## The Hunter Valley test

On Sept. 30, the commission [approved the continuation](https://www.ipcn.nsw.gov.au/news/hunter-valley-operations-coal-mine-approved-conditions) of Hunter Valley Operations, a joint venture of Yancoal and Glencore, letting mining run to 2045 at its northern pit and 2042 at its southern one. The [Climate Council puts the coal at 430 million tonnes](https://www.climatecouncil.org.au/resources/hunter-valley-operations-what-happens-now-nsw-has-approved-it-biggest-ever-coal-mine/). The commission found the project would release 809 million tonnes of greenhouse gases, most of it from coal burned overseas. Its conditions require a Scope 3 Management Plan within three months showing how the operator is “limiting coal exported from the mine to jurisdictions with greenhouse gas emissions policies consistent with the goals of the Paris Agreement,” along with carbon offsets beyond those the federal Safeguard Mechanism requires.

Sue Higginson, a Greens member of the state Parliament, said the project’s environmental impact statement ignored scope 3 entirely. “It seems clear that the approval of HVO fails this test,” she said. The state government says the HVO assessment did consider scope 3. Nic Clyde, state coordinator of the Lock the Gate Alliance, said the ruling would affect 17 coal projects in the state’s planning pipeline. Nationally, the Australia Institute counts about 30 applications for new or expanded coal mines awaiting approval, [Briefs reported](https://www.briefs.co/news/australia-s-high-court-says-mine-approvals-must-weigh-coal-s/).

The Court of Appeal had floated conditions of the HVO kind, including exporting only to Paris Agreement signatories, offsetting scope 3 emissions or processing coal before export, AAP reported. No court has ruled on whether a condition on where coal may be sold minimizes emissions “to the greatest extent practicable.” The state’s own Net Zero Commission advised in July that new coal approvals are “not consistent with” the state’s legislated targets or the Paris goals.

## Gas and Canberra

Murray Watt, the federal environment minister, called it a “novel decision” and said: “The decision from the High Court is in relation to a NSW government decision based on NSW legislation.” National law gives him little reason to revisit that. The environment law overhaul Parliament passed in November 2025 requires large projects to disclose scope 1 and 2 emissions but not scope 3, and does not require the minister to weigh emissions in deciding on a project, [according to an analysis by the law firm Jones Day](https://www.jonesday.com/en/insights/2026/09/amendments-to-australias-environment-protection-and-biodiversity-conservation-act-1999-and-their-impacts-on-climate-chan). Mr. Watt has said the Safeguard Mechanism, which requires large emitters to cut on-site emissions 4.9 percent a year or buy offsets, remains the federal tool.

Gas is less sheltered inside New South Wales. The state clause covers petroleum production as well as mining, so a new gas approval there carries the same duty to consider conditions on downstream emissions, though the Narrabri ruling shows that a commission which weighs such conditions and declines them can survive review. Liz Hicks of the University of Melbourne told [ABC News](https://www.abc.net.au/news/2026-10-07/mount-pleasant-coal-mine-high-court-ruling/107233650) that the ruling rests on New South Wales law, limiting its direct reach, though courts elsewhere “will take note.” In Western Australia, the Australian Conservation Foundation is already in court against Woodside’s Browse gas project on climate grounds, with a United Nations special rapporteur, Astrid Puentes Riaño, joining as amicus curiae, Reuters reported.

## Courts abroad

On June 20, 2024, Britain’s Supreme Court ruled 3-2, the same margin, that Surrey County Council acted unlawfully in approving oil production at Horse Hill without assessing the emissions from burning the oil, [Jones Day wrote](https://www.jonesday.com/en/insights/2024/07/uk-supreme-court-issues-landmark-ruling-on-downstream-ghg-emissions). Lord Leggatt’s lead judgment held that those emissions were within the operator’s control, because it could choose not to extract the oil. Three months later, the High Court of England and Wales quashed approval for a new coal mine at Whitehaven in Cumbria, and the developer withdrew its planning application on March 31, 2025.

On May 21, 2025, the EFTA Court, which interprets European Economic Area law for Norway, Iceland and Liechtenstein, [advised](https://www.nhri.no/en/2025/new-efta-court-judgment-combustion-emissions-must-be-assessed-and-unlawful-production-licences-must-be-remedied/) that combustion emissions from three Norwegian oil and gas fields had to be assessed before approval, even when the burning happens abroad. In the United States the question is arriving by another route: Boulder, Colo., is defending before the Supreme Court a suit against Exxon and Suncor that the city says is [about deception, not emissions](https://rews.cc/a/eight-justices-weigh-whether-boulder-can-make-exxon-and-sunc-eebd92). None of the European rulings forbids a fossil fuel project. Each requires the decision-maker to reckon with the fuel’s end use before saying yes.

## What comes next

The Mount Pleasant expansion now returns to the Land and Environment Court, which will decide whether the application goes back to the commission for a fresh decision, AAP reported. It was not clear when that would happen. The state government had not said by Wednesday whether it would amend the planning law as the Coalition and the Minerals Council demand. The last attempt, the 2019 Territorial Limits Bill, never passed.

The nearer deadlines belong to HVO. The mine was due to close in December, putting an estimated 1,500 jobs at risk, and it needs federal environmental approval by the end of December to keep operating, [2NM reported](https://www.2nm.com.au/local-news/ipc-approves-hvo-coal-mine-continuation-with-strict-climate-conditions/). Under the commission’s conditions, its operator has until the end of December, three months from the Sept. 30 approval, to publish the plan that says where HVO’s coal may be sold.

## See also

- [Should emissions from coal burned overseas be considered in Australian mine approvals? (The Conversation)](https://theconversation.com/should-emissions-from-coal-burned-overseas-be-considered-in-australian-mine-approvals-for-the-first-time-the-high-court-will-decide-281343) — theconversation.com · Pre-hearing explainer by Maria Nawaz of UNSW on the case and its stakes
- [High Court hearing transcript, May 13, 2026](https://www.austlii.edu.au/cgi-bin/viewdoc/au/other/HCATrans/2026/29.html) — austlii.edu.au · The full oral argument before the five justices
- [MACH Energy's written submissions to the High Court](https://www.hcourt.gov.au/sites/default/files/2026-02/MACH-Denman_App.pdf) — hcourt.gov.au · The company's own legal case, in its words
- [NSW Court of Appeal judgment in DAMSHEG v MACH Energy (2025)](https://cdn.climatepolicyradar.org/navigator/AU-NSW/2022/denman-aberdeen-muswellbrook-scone-healthy-environment-group-inc-damsheg-v-mach-energy-australia-pty-ltd_6dac6d867787c073bb7e5781913d17a4.pdf) — cdn.climatepolicyradar.org · The unanimous ruling the High Court upheld on different grounds
- [High Court hears bid to overturn block on Mount Pleasant extension (ABC News)](https://www.abc.net.au/news/2026-05-13/high-court-climate-change-mining-projects-planning-authority/106671456) — abc.net.au · How each side framed the appeal on the day of the hearing
- [The detail: what's in Australia's new environment laws (Environmental Justice Australia)](https://envirojustice.org.au/the-detail-whats-in-australias-new-environment-laws/) — envirojustice.org.au · What the 2025 federal overhaul does and does not require on emissions

## Sources

- [Australia’s top court blocks coal mine expansion, citing climate harm](https://aljazeera.com/news/2026/10/7/australia-top-court-rules-against-coal-mine-expansion-citing-climate-harm) — aljazeera.com
- [Australian High Court rules in favour of climate group in Hunter Valley coalmine case](https://rnz.co.nz/news/world/1782134/australian-high-court-rules-in-favour-of-climate-group-in-hunter-valley-coalmine-case) — rnz.co.nz