As was highlighted in our recent articles on climate change class actions and the rise of "greenwashing" litigation, it is increasingly common to see environmental groups and affected persons commence court proceedings, pursuing more novel ways to protect the environment and seek remedies for alleged impacts of climate change caused by the actions of governments, businesses and individuals.

A recent decision of the Montana District Court in the United States – Held v State of Montana – is another significant climate change decision, which shows the potential impact that an environmental lawsuit can have on businesses and government policy.

Held v State of Montana

The case centred around certain statutory provisions in the Montana Energy Policy Act ("MEPA"). In 2020, when the plaintiffs filed their claim, the MEPA stated that "actual or potential environmental impacts" that are "regional, national or global in nature" could not be considered in governmental reviews of new energy related projects. This had the effect of limiting the consideration of actual or potential environmental impacts, including those linked to climate change ("MEPA Limitation").

In 2023, the MEPA was amended to more expressly clarify that the impacts of climate change could not be considered in government reviews of new projects. The amendments prohibited Montana's agencies from considering "an evaluation of greenhouse gas emissions and corresponding impacts to the climate in the state or beyond the state's borders".

The plaintiffs in this case were 16 young people from Montana who, at the time the Complaint was filed in March 2020, were aged between two and eighteen years old. They alleged that the State mandated policy was unconstitutional. In particular, the plaintiffs alleged that this policy, which prevented environmental considerations from being taken into account, violated their constitutional rights as guaranteed under the 1972 Montana Constitutional Convention that "[t]he state and each person shall maintain and improve a clean and healthful environment in Montana for present and future generations".

Key takeaways from the Court's decision

Extensive scientific evidence was presented at trial relating to climate science and projections. The court also considered the impact that climate change was said to have on children and specifically the youth plaintiffs in terms of their mental and physical health. District Court Judge Kathy Seeley found in favour of the plaintiffs.

The Court held that:

  • greenhouse gas emissions in Montana were traceable to the MEPA Limitation and that these emissions were a substantial factor impacting Montana's environment and causing harm and injury to the plaintiffs.
  • the plaintiffs had experienced past and ongoing injuries resulting from the State's failure to consider greenhouse gas emissions and climate change, including injuries to their physical and mental health, homes and property, recreational, spiritual and aesthetic interests, tribal and cultural traditions, economic security, and happiness.
  • the plaintiff's mental injuries stemming from the effects of climate change on Montana's environment (feelings such as loss, despair and anxiety) were cognizable injuries, which would grow increasingly severe and irreversible without science-based actions to address climate change.
  • the plaintiffs have a fundamental constitutional right to a clean and healthful environment, which includes climate.
  • the MEPA Limitation violated the plaintiffs' constitutional right to a clean and healthful environment and was unconstitutional on its face.

Significance of the decision

Held v The State of Montana is the first ever constitutional climate change case in US history to go to trial. In Montana, the decision means that the State is now legally required to factor in climate change impacts of proposed energy projects into its decision-making process. This decision could inspire more lawsuits, particularly in other states in the US with similar constitutional provisions.

Elsewhere around the world, we have seen Courts in Germany, the UK and France already hand down significant judgments in relation to other climate change related lawsuits. The UK Supreme Court recently heard the appeal in R (on the application of Finch on behalf of the Weald Action Group) v Surrey County Council and others which is about whether downstream greenhouse gas emissions require to be considered as part of an environmental impact assessment for an onshore oil well site. We expect that with the increasing number of non-profit legal organisations being established to litigate climate change issues, including those which are youth-led, the number of these kind of lawsuits will only increase.

In Scotland, we have previously noted the ongoing calls for the Scottish Government to establish a specialist environmental court or tribunal.

Given the increasing public scrutiny and attention on climate related issues, this decision highlights the importance of individuals, companies and public bodies carefully considering their obligations in respect of the environment and the sorts of legal challenges that can be brought in court.


Niall McLean

Partner & Solicitor Advocate

Rebecca Morrison

Associate (Qualified in Australia)

Clara Wilson

Trainee Solicitor