Montana Supreme Court denies youth litigants' effort to strike down emissions laws

By EPN Staff

In a back-and-forth volley of Montana’s environmental law, the state's Supreme Court denied a petition brought be a group of youths to invalidate three state laws. The petition claimed the laws violate the state Constitution’s “right to a clean and healthful environment.” 

A year ago, the same high court ruled in favor of the petitioners in an earlier lawsuit in Held v. Montana (2024) that contended the environment clause in the state constitution guarantees a “stable climate.” That decision struck down a 2023 law that prevented state regulators from considering climate impacts when granting permits for energy projects under the Montana Environmental Policy Act (MEPA). 

In the Dec. 23, 2025, ruling, the justices said the petitioners failed to show their suit met the “emergency” criterion that would have allowed them to bypass the trial court. The plaintiffs can pursue their case through the lower courts, however.

Why it matters

The 2025 suit, filed by 13 of the original 16 youths from the 2024 case, contended that three laws passed earlier this year, House Bills 285 and 291, and Senate Bill 221, were unconstitutional under the same reasoning. 

In 2025, Republicans brought several bills before the Montana legislature to replace those ruled unconstitutional the year before, according to the Daily Montanan. 

• HB 285 amended the MEPA to allow agencies to assess greenhouse gas emissions for projects but clarified that the MEPA is an assessment rather than a regulatory tool. It states that, “An agency may not withhold, deny, or impose conditions on any permit or other authority to act” based on the assessment.  
• SB 211 directed agencies to focus on direct environmental impacts and prohibited them from assessing “upstream, downstream, or other indirect action” that might be caused by the proposed project under the MEPA. 
• House Bill 291 forbids the state from imposing a stricter standard for air pollution than the standard set by federal Clean Air Act regulations.

In each case, plaintiffs asserted that the laws prevent state agencies from foisting what they consider to be necessary limits on fossil fuel emissions through the MEPA process and clean air standards. 

The bigger picture

Since 2015, groups of youth with the support of legal advocacy group Our Children’s Trust have lodged suits in all 50 states alleging that laws, policies, and regulations violate state constitutional guarantees. In 2024, they won two cases, Held v Montana and Navahine v. Hawai‘i Department of Transportation. 

In Held v Montana, 16 youths sued the state of Montana, the governor and state agencies, alleging that certain laws contributed to climate change and were causing them harm. They sought to invalidate laws that they believed violated the state constitution by encouraging fossil fuel development and banning regulators from considering greenhouse gas emissions in MEPA reviews. 

The First Judicial District Court and later the Montana Supreme Court ruled in favor of the plaintiffs, holding that the state constitutional right to “a clean and healthful environment” includes a “stable climate.” The high court also found that the youth had standing to challenge the MEPA provision that excluded greenhouse gas emission consideration and that it was unconstitutional. 

In the 2024 Navahine v. Hawai‘i Department of Transportation case, plaintiffs and defendants came to a settlement, and the state government agreed to implement programs to decarbonize the state’s transportation system to reduce carbon emissions.