Montana Supreme Court Upholds Climate Ruling Enshrining Right to a "Stable Climate"

On December 18, 2024, the Montana Supreme Court issued a ruling upholding a lower state court's decision that, under Montana's constitution, there is a “fundamental constitutional right to a clean and healthful environment [that] includes climate as part of the environmental life support system.”  This decision also upheld the lower court's determination that a Montana law at issue violated the state constitution by “prohibit[ing] environmental reviews from evaluating GHG [i.e., greenhouse gas] emissions.”  In other words, the Montana Supreme Court, relying upon particularly protective language in the Montana state constitution, held that climate change is significant and must be taken into account in order to preserve the constitutional rights of Montana residents.  

That a state supreme court has reached such a decision is undoubtedly significant.  This is now the law in Montana--and effectively unreviewable by the Supreme Court, as this decision is based upon state law, and so beyond the purview of the Supreme Court's appellate authority.  This ruling may also serve as a model for other state courts that have similar provisions in their respective state constitutions (although there are relatively few such states).

Perhaps most importantly, this victory by activists pursuing constitutional climate litigation--i.e., that state protection from climate change is a constitutional right--will likely encourage further lawsuits along the same lines, and cases of this sort may well proliferate in the near future.