Proponents of more comprehensive climate regulations who are frustrated by the federal government have increasingly turned their attention to state litigation.

Over the years, we have written about these efforts, most recently here. In what is perhaps the leading state case on these issues, Held v. State of Montana, the Montana Supreme Court ruled this week that the Montana Constitution’s right to a clean and healthful environment includes the right to a stable climate system. The decision upheld a trial court order striking down a law that forbade state agencies from considering greenhouse gas (GHG) emissions in Montana Environmental Policy Act (MEPA) reviews.

Montana joins Hawaii as the second state to explicitly enshrine climate-related rights in its constitution. While the decision may result in the plaintiffs seeking to expand these rights at the state level, Montana’s political environment will likely dampen its practical effect.

Background

In 2020, a group of Montana children sued the State of Montana, arguing that state policies enabling the production and consumption of fossil fuels violated their right to a clean and healthful environment. Specifically, the children sought an injunction ordering the state to reduce GHG emissions, subject to ongoing court oversight. And, they said, a state law preventing MEPA reviews from considering global environmental impacts was unconstitutional.

Amended in 1972, the Montana Constitution contains what is often called a “Green Amendment,” a constitutional clause obligating the state to provide a clean and healthful environment. The Montana Constitution provides that “[t]he state and each person shall maintain and improve a clean and healthful environment in Montana for present and future generations.” In addition, the Montana Bill of Rights guarantees an inalienable right to “a clean and healthful environment.” For its part, MEPA requires environmental review of “major actions of state government significantly affecting the quality of the human environment.” (See generally here.)

In 2023, a Montana trial court ruled that MEPA required state agencies to examine climate change impacts in Montana. In response, the Montana Legislature enacted a law banning “an evaluation of greenhouse gas emissions and corresponding impacts to the climate” from MEPA reviews.

After an eight-day trial, the district court ruled in favor of the children (a decision we covered here).

Decision Summary

The Montana Supreme Court addressed whether the Montana Constitution provides a right to a stable climate system, whether the MEPA limitation violates that right, and whether plaintiffs had standing to bring their claim.

First, the court looked to legislative history from the 1972 Montana Constitutional Convention, noting the framers’ desire to add strong environmental protections. The court emphasized that the right to a clean and healthful environment is “forward-looking and preventative.” It invoked the principle that the Montana Constitution is “not a straight-jacket, but a living thing, designed to meet the needs of a progressive society.”

The court determined that Montana’s right to a healthful environment includes a right to a stable climate, even if climate change was not on the radar in 1972. The court rejected the idea that the Montana Constitution’s framers “would grant the State a free pass to pollute the Montana environment just because the rest of the world insisted on doing so.”

On standing, the court ruled that plaintiffs established an injury to their constitutional right to a clean and healthful environment because the MEPA limitation prevents the state from considering GHG emissions. It held that the law, by arbitrarily constraining the environmental dangers state agencies can consider, violates the state right to a clean and healthful environment.

Takeaways

The regulated community should take away three points from this decision:

• Climate-Related Rights May Be Found in State Constitutions: Montana joins Hawaii as the second state to recognize a state constitutional right to a stable climate system. Climate plaintiffs may try to generate momentum from this victory and pursue similar arguments in other states with constitutional environmental protections. There is a limit to how far this strategy might go: only a handful of states have constitutional environment clauses, including Hawaii, Illinois, Massachusetts, Montana, New York, Pennsylvania, and Rhode Island. (See our discussion of litigation involving New York’s Green Amendment here.)
• State Constitutions Have Varying Language Leading to Different Case Outcomes: In 2021, a Washington state appellate court ruled that the Washington Constitution’s due process and rights retained by the people clauses did not create a right to a healthful environment and stable climate system. That decision may reflect the uphill battle climate plaintiffs face in states without explicit environmental protections in their state constitutions.
• State Politics Still Matter: Montana is no bastion of liberalism, so its legislature and governor likely will not build out procedures to protect the rights identified in this week’s decision. As a result, climate plaintiffs may need to return to court if they wish to compel the state to reduce its GHG emissions. But, asking state courts to affirmatively set climate policy raises separation of powers concerns. It may be easier for courts to require the legislative and executive branches to consider climate impacts, as Held does, than to mandate any substantive changes to climate policy.