· 2026-10-15T23:34:07+0000 · 16 posts

98 per cent of the emissions, no conditions considered: why a coal mine approval fell

A 3:2 High Court held that a NSW coal mine extension approval was invalid because the Commission never considered conditions to minimise Scope 3 emissions, 98% of the project's emissions. The duty was to consider such conditions, not to impose them.

In MACH Energy Australia Pty Ltd v Denman Aberdeen Muswellbrook Scone Healthy Environment Group Inc [2026] HCA 35, the High Court of Australia (Gageler CJ, Gordon, Edelman, Jagot and Beech-Jones JJ) decided whether the approval of a 22-year extension of the Mount Pleasant coal mine in the Hunter Valley was valid. The result was that the approval was invalid, by a 3:2 majority. The important point is that the planning law required the consent authority to consider conditions to minimise all of the project's greenhouse gas emissions, including the downstream "Scope 3" emissions from burning the exported coal, and it never did. All paragraph references below are to the judgment.

Why it matters: This is a judicial review decision, not a ruling on whether coal mines should be approved. The Court did not say that conditions on Scope 3 emissions must be imposed. It held that a decision maker who must consider something has to actually turn its mind to it, and that putting 98 per cent of a project's emissions to one side is not doing that ([80], [202]).

At a glance

Court and level: High Court of Australia (Full Court), on appeal from the NSW Court of Appeal
Area of law: Administrative law; environmental and planning law (NSW)
Decision type: Appeal in judicial review proceedings
Outcome: Appeal dismissed 3:2 (Gordon, Edelman and Beech-Jones JJ; Gageler CJ and Jagot J dissenting); the consent was invalid
Standard of review: Jurisdictional error, including materiality, not merits review ([264])
Costs: Appeal dismissed with costs (Order 2)

🧩 Facts and Issues

Background

The mine owner, MACH Energy Australia Pty Ltd ("MACH"), applied to extend the life of the Mount Pleasant open cut mine by 22 years, to 22 December 2048, allowing about 406 million more tonnes of coal to be extracted ([2], [73]). As State significant development, the application was decided by the Independent Planning Commission of NSW ("the Commission") ([3]).

Scope 1 and 2 emissions (from the mine's own operations and the energy it uses) were about 2 per cent, or 16.07 million tonnes, of the project's emissions. Scope 3 emissions (mostly from third parties burning the product coal) were about 98 per cent, or 860 million tonnes ([230]). The Commission imposed several conditions on Scope 1 and 2 emissions, but none on Scope 3 emissions were imposed or even discussed ([230]). It reasoned that Scope 3 emissions were accounted for under national policies and international agreements such as the Paris Agreement, in the countries where the coal is burnt ([187]–[188]).

How the case got here

A community environmental group, Denman Aberdeen Muswellbrook Scone Healthy Environment Group Inc ("DAMSHEG"), sought judicial review (a court check of whether the decision was lawfully made) in the Land and Environment Court. Robson J dismissed the challenge ([9]). The NSW Court of Appeal allowed DAMSHEG's appeal on one ground: it held the Commission had failed to consider the development's likely impacts "in the locality" under s 4.15(1)(b) of the Environmental Planning and Assessment Act 1979 (NSW) ([10]). MACH appealed to the High Court by special leave ([11]).

What each side argued

MACH argued that the Court of Appeal misread s 4.15(1)(b) as requiring a separate consideration of impacts "in the locality" ([11]).
By notice of contention (an argument that the result below should stand for a different reason), DAMSHEG argued that the Commission breached cl 2.20(1)(c) of the State Environmental Planning Policy (Resources and Energy) 2021 (NSW) by never considering conditions to minimise Scope 3 emissions ([12]).
MACH also argued, relying on Ross v Lane, that even a failure to consider such matters could not invalidate the consent ([15]).

The issues

Did s 4.15(1)(b) require separate consideration of impacts "in the locality"?
Did the Commission consider whether to impose conditions to minimise Scope 3 emissions?
If not, was the error material, so that the consent was invalid?

⚖️ Applicable Law – Legislation, Rules and Principles

Environmental Planning and Assessment Act 1979 (NSW), s 4.15(1): the consent authority must take into consideration the listed matters "as are of relevance to the development", including the provisions of any environmental planning instrument (s 4.15(1)(a)(i)) and "the likely impacts of that development" (s 4.15(1)(b)) ([1], [23]).
State Environmental Planning Policy (Resources and Energy) 2021 (NSW), cl 2.20(1)(c): before granting consent for mining, the consent authority must consider whether consent should be issued subject to conditions to ensure "that greenhouse gas emissions are minimised to the greatest extent practicable" ([12], [77]). Clause 2.20(2) separately requires it to consider an assessment of emissions "including downstream emissions" ([69]).
Land and Environment Court Act 1979 (NSW), Div 3 of Pt 3: where a consent is invalid, the Land and Environment Court must consider orders such as suspending the consent or setting terms that will validate it, instead of simply declaring it invalid ([78]).
Materiality: an error is generally jurisdictional (serious enough to make the decision invalid) only if there is a realistic possibility that the decision could have been different without it ([169], [195]).

📌 Authorities Relied On

Ross v Lane: NSW Court of Appeal decision on whether matters under s 4.15(1) are for the consent authority or the court; the Chief Justice and Jagot J held that s 4.15(1) imposes a duty to consider matters that are objectively relevant ([15]–[23]).
Woolworths Ltd v Pallas Newco Pty Ltd: earlier Court of Appeal authority distinguished in Ross v Lane ([17]–[19]).
LPDT v Minister for Immigration, Citizenship, Migrant Services and Multicultural Affairs: the materiality threshold for jurisdictional error ([192]–[193]).
KEPCO Bylong Australia Pty Ltd v Bylong Valley Protection Alliance Inc: the Court of Appeal upheld a refusal of a coal mine where no condition addressed Scope 3 emissions ([198], [212]).

🧠 Analysis

Issue

Whether the Commission lawfully considered the matters the planning law required, especially conditions to minimise Scope 3 emissions.

Rule

The consent authority must genuinely consider each mandatory matter. The court does not review the merits, or decide what conditions should have been imposed ([80], [264]).

Application

The Court of Appeal's "in the locality" reading was wrong

All five Justices rejected the Court of Appeal's reading of s 4.15(1)(b). The provision requires consideration of "the likely impacts of [the] development" generally; those impacts often include impacts in the locality, but identifying them is for the consent authority ([14], [76], [216], [276]). MACH won this point.

Considering Scope 1 and 2 was not considering all emissions

The majority held that cl 2.20(1)(c) required the Commission to consider conditions for all greenhouse gas emissions identified in the environmental impact statement, including Scope 3 ([169], [318]). Its detailed treatment of the 2 per cent of Scope 1 and 2 emissions suggested it would have said so if it had considered conditions for the other 98 per cent ([186], [215]). The structure of its reasons showed it put Scope 3 emissions to one side as accounted for elsewhere before it turned to cl 2.20(1)(c) ([187]–[189]). A general statement that it had "considered all emissions" did not fix that, read in context ([231]–[233]).

The objector did not have to propose conditions

The Court of Appeal had treated DAMSHEG's "forensic choice" not to propose Scope 3 conditions as fatal. The majority disagreed. The statutory scheme put the responsibility to propose mitigation measures on MACH as proponent ([196]–[197]). Beech-Jones J added that a public planning decision is not an adversarial contest, and the public interest "loomed large" ([315]–[316]).

The error was material

There was a realistic possibility that, had the Commission considered the question, conditions could have been imposed; MACH could not show approval without such conditions was inevitable ([195], [199]–[201], [319]).

The dissent

The Chief Justice and Jagot J would have allowed the appeal. They read the Commission's reasons as discharging cl 2.20 as a whole, including through its references to the policy framework and its express statement that it had considered cl 2.20(1) ([66]–[71]).

Conclusion

The consent was affected by jurisdictional error and invalid. The Court did not decide Ground 3 (whether climate change can be an impact "in the locality") ([79], [205]).

🏛️ Outcome, Orders and Costs

Order 1: DAMSHEG was granted leave to file an amended notice of contention.
Order 2: The appeal was dismissed with costs.
The Court of Appeal's remitter to the Land and Environment Court stands. That Court must consider orders under Div 3 of Pt 3 of the Land and Environment Court Act 1979 (NSW), such as suspending the consent or specifying terms that would validate it ([78], [203]).

🧭 Practical Lessons

For self-represented litigants: Judicial review is about how a decision was made, not whether it was right. Frame the challenge around a specific statutory duty the decision maker missed ([264]).
For self-represented litigants: Read the decision maker's reasons closely. What they discuss in detail, and what they skip, can show what they did not consider ([186]–[188]).
For practitioners: A recital of the statutory test, or a general statement that "all" matters were considered, will be read in context and may not be enough ([231]–[233]).
For practitioners: In NSW planning, the proponent carries the job of proposing mitigation conditions; objectors are not required to draft them ([196]–[197]).
For practitioners: Even with jurisdictional error, the remedy in planning cases can be validation or suspension under the LEC Act rather than outright invalidity ([78]).

🧠 Take-Home Lesson

A duty to consider is a duty to actually think about the question.
Setting aside most of the problem is not considering it.
The High Court did not require Scope 3 conditions; it required the question to be asked.

"If the law says consider it, the reasons must show you did. All of it, not two per cent of it."

This digest is general information about a published judgment, not legal advice. For advice about your own situation, speak to a lawyer, Legal Aid or a community legal centre.