A Montana state judge ruled Monday that a provision of state law is unconstitutional because it violates “the right to a clean and healthful environment,” a fundamental right enshrined in Montana’s Constitution. The ruling is in favor of a group of youth plaintiffs who alleged that the state of Montana failed to protect them and future generations from the harmful effects of climate change. The case, Held v. Montana, is the first constitutional climate suit in US history to make it to trial. 

The Montana First Judicial District Court held that a limitation in the Montana Environmental Policy Act (MEPA) prohibiting the consideration of greenhouse gas emissions (GHG emissions) when reviewing energy and mining projects violates the state constitution because it “categorically limits” what government actors can examine when working to protect Montana’s environment. According to the court:

The MEPA Limitation is unconstitutionally contributing to the depletion and degradation of Montana’s environment and natural resources and contributing to Plaintiffs’ injuries. … By prohibiting consideration of climate change, GHG emissions, and how additional GHG emissions will contribute to climate change or be consistent with the Montana Constitution, the MEPA Limitation violates Plaintiffs’ right to a clean and healthful environment and is facially unconstitutional.

Additionally, the court noted that the state did not advance “any evidence of a compelling governmental interest for the MEPA Limitation.”

The decision permanently enjoins the MEPA Limitation, effectively permitting state agencies and officials to again consider the effects of GHG emissions and climate change.

Monday’s unprecedented ruling is expected to shape how many other states address the impacts of climate change at the judicial level. According to a 2o22 report, climate change litigation has grown significantly across the globe, with cases more than doubling in the past seven years.

“I think this is the strongest decision on climate change ever issued by any court,” environmental law expert Michael Gerrard posted following the decision. In a press release, Julia Olson, the Executive Director of the non-profit law firm that brought the case, said:

As fires rage in the West, fueled by fossil fuel pollution, today’s ruling in Montana is a game-changer that marks a turning point in this generation’s efforts to save the planet from the devastating effects of human-caused climate chaos. This is a huge win for Montana, for youth, for democracy, and for our climate. More rulings like this will certainly come.