Youth-led climate lawsuits and the significance of the decision in Montana v Held. Week 3. Series 3

6 December, 2023

Youth-led climate lawsuits and the significance of the decision in Montana v Held

Author: Ellen Tims

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On 13 March 2020, 16 young Montanans, then aged between 2 and 18, filed a lawsuit alleging that Montana was violating their constitutional right to a clean and healthful environment because of a law that barred state officials from considering climate change in environmental reviews of energy policies. That lawsuit became the first constitutional climate trial in US history. On 4 August 2023, Judge Kathy Seeley of the Montana 1st Judicial District Court handed down a landmark ruling in favour of the young Montanan climate activists: Held v Montana, No. CDV-2020-307 (1st Dist. Ct. Mont., Aug. 14, 2023).

This reflects a burgeoning trend of climate lawsuits being brought by young climate activists around the world. By way of example only:

  • A class action suit is pending in Sweden, whereby a group of over 600 young people born between 1996 and 2015 (including Greta Thunberg) contend that Sweden’s actions to mitigate climate change are inadequate and thus in violation of their rights under the ECHR: Anton Foley and others v Sweden (the ‘Aurora’ case).
  • In late September 2023, the Grand Chamber of the ECtHR heard a case brought by six young Portuguese citizens against 33 European governments for their failure to take sufficient action in response to global warming: Duarte Agostinho and Others v Portugal and 32 Others, Case No. 39371/20. This is the largest climate case that has ever been heard by the Strasbourg court. A ruling is anticipated in the first half of 2024.
  • There are a number of similar lawsuits currently underway in other US states, such as in Hawaii: Nawahine v the Hawai’i Department of Transportation (this trial, which concerns the state’s transportation policies, is scheduled to take place in July 2024). The states in which similar lawsuits are pending have environmental constitutional protections similar to Montana’s. The first federal constitutional complaint in respect of climate change is also presently awaiting trial, having failed previously to gain traction in the face of several opposing motions by the US Department of Justice to dismiss and/or delay the complaint: Juliana v United States. In June 2023, Judge Ann Aiken of the US District Court for the District of Oregon granted the plaintiffs permission to amend – and therefore revive – their challenge.

As an important milestone in this emergent jurisprudence, the ruling in Held v Montana provides insight into the arguments that may be successfully run, and the challenges that may be faced, in youth-led climate lawsuits of this type.

The narrow and particular context of the Montana state court’s ruling

At the outset, it is helpful to point out some of the peculiarities of the claim before the Montana state court.

First, the lawsuit was a constitutional challenge founded on a particular constitutional right – the inalienable right to a clean and healthful environment – that features in only a handful of US state constitutions (Constitution of Montana, Article II, Part II, Sec. 3). However, the right to a healthy environment does have constitutional status in approximately 150 other countries.

Second, the target of such challenge was a particular provision within the Montana Environmental Policy Act (“MEPA”) known as the “MEPA Limitation” (MEPA, Mont. Code Ann. §75-1-201(2)(a)). Since 2011, the MEPA Limitation had prevented state agencies from evaluating greenhouse gas emissions and corresponding climate impacts – both within the State and beyond its borders – when conducting environmental reviews under MEPA. That prohibition had been strengthened and clarified by a 2023 amendment to the MEPA Limitation.

Third, the outcome or remedy in this case was reasonably muted in practical terms. The striking down of the MEPA Limitation permitted Montana’s decision makers to consider the greenhouse gas emission and climate impacts of proposed projects, but it did not impose any positive or substantive obligations on agencies to withhold approvals on this basis, nor to adopt a greenhouse gas mitigation strategy. Further, it is open to the Montana State Legislature to determine how it complies with this ruling, which may take some time due to (i) the state’s significant existing fossil fuel and mining interests, and (ii) Republican dominance in the Montanan statehouse.

Fourth, the fate of this ruling is uncertain in view of Montana’s pending appeal to the state Supreme Court (note that the US Supreme Court does not take on cases such as this that are based purely on state law). We can expect a final ruling from the state Supreme Court in around a year.

These points demonstrate that the ruling is, strictly viewed, narrow in its ambit. As the ruling was (i) based on the enforcement of a unique and specific constitutional environmental right, (ii) directed towards striking down a particular part of state legislation, we must be cautious in transposing its reasoning and outcome too readily to other contexts. Naturally, the decision may pave the way for similar challenges in other US states or countries across the globe whose constitutions contain equivalent environmental protections. But, more importantly, what might it mean for youth-led or other climate litigation of this sort more generally?

Potential takeaways from the ruling

The following three points may be taken away from the decision.

First, the ruling includes wide-ranging findings of fact in relation to global warming and greenhouse emissions, which (i) may be cited in future cases, and (ii) demonstrate court receptiveness to the latest climate data. This case was only the second US trial where climate scientists took the stand, were placed under oath, and then subjected to cross-examination. Judge Seeley’s ruling contains a rare and rigorous examination of the contemporary climate attribution science, which adds a wealth of relevant data to the record. The ruling comprises over 70 pages of factual findings that may be cited and/or summarised in future trials, referencing, for example, the famous Keeling Curve displaying increased amounts of atmospheric carbon dioxide. It traverses the latest climate science and data on the significant and concrete contribution of anthropogenic fossil fuel combustion to a real discernible increase in global temperatures. Even if, on appeal, District Judge Seeley’s approach is reversed, it is likely that such departure will rest on a legal basis and not disturb the historic factual findings recorded as part of the order.

It is noteworthy that the state withdrew its only scientific witness, who proposed to downplay the impacts of climate change. The expectation was that Montana would mount a more vigorous defence that countered the Plaintiffs’ expert evidence. Further, it was never part of Montana’s scientific case that climate change is either not real or not anthropogenic. This suggests that although climate science denial has long had a political platform, it may assume a more vulnerable position within the courtroom.

Second, the reasoning as to (i) Plaintiffs’ injury, and (ii) causation, may provide a blueprint for other similar claims.

Three aspects of Judge Seeley’s reasoning on the Plaintiffs’ proven injury are noteworthy:

  • The Plaintiffs’ mental health injuries directly resulting from state inaction or counterproductive action on climate change, on their own, did not establish a cognizable injury (Findings of Law, [5], p. 86).
  • The Plaintiffs’ mental health injuries stemming from the effects of climate change on Montana’s environment, including feelings such as loss, despair and anxiety, constituted cognizable injuries (Findings of Law, [5], p. 87). Judge Seeley made a number of explicit factual findings recognising that the young Plaintiffs were and are in fact suffering mental health impacts stemming from climate change. Crucially, this represents the first time an American court has found that climate anxiety is a cognizable injury.
  • As children and youth, the Plaintiffs were disproportionately harmed by fossil fuel pollution and climate impacts (Findings of Law, [8], p. 87). Their proven injuries were concrete, particularized, and distinguishable from those suffered by the public more generally (Findings of Law, [9], p. 87).

Further, Judge Seeley traced a well-defined causal pathway from Montana’s authorisation of fossil fuel projects to the concrete injuries suffered by the Plaintiffs. She found a ‘fairly traceable connection’ between (i) the state’s disregard of greenhouse gas emissions and climate change pursuant to the MEPA Limitation, (ii) greenhouse gas emissions over which the state has control, (iii) climate change impacts, and (iv) the Plaintiffs’ proven injuries (Findings of Law, [13], pp. 87-88). Further, she determined that Montana’s greenhouse gas contributions are not de minimis but nationally and globally significant, thus contributing both to climate change, and the Plaintiffs’ injuries (Findings of Law, [16], p. 88). This recognises that even political choices of a state with a small population such as Montana can have a meaningful impact on climate change, because “[e]ach additional ton of GHGs emitted into the atmosphere exacerbates impacts to the climate…” (Findings of Fact, [91], p. 24). Recognition of that fact served to dislodge a fundamental pillar of the state opposition – namely that the reduction in Montana’s greenhouse gas emissions that would result from the declaration of the MEPA Limitation as unconstitutional would not provide any redress for the Plaintiffs’ injuries (cf. Judge Seeley’s finding of partial redressability: Findings of Law, [20]-[21], p. 89).

Third, the ruling serves an important signalling function. Taking a broader view, the ruling sends out a positive signal of judicial receptiveness from the claimant perspective, which may be energizing for young people, climate activists, and their lawyers. By way of example, the US Environmental Protection Agency issued a statement hailing the decision as “set[ting] a precedent for intergenerational accountability and environmental justice…” Such a strong decision in favour of the claimants in Held v Montana may suggest greater prospects for youth-led climate lawsuits from the claimant standpoint and will likely shape the form of climate litigation we see going forwards.


This note is provided free of charge as a matter of information only. It is not intended to constitute, nor should it be relied upon as constituting, legal advice, and no responsibility is assumed in relation to the accuracy of the contents of the same as regards anyone choosing to rely upon it.