The Montana Supreme Court on Wednesday upheld a district court ruling in the nation’s first constitutional climate change trial, affirming that the youth plaintiffs have a “fundamental constitutional right to a clean and healthful environment” while revoking two Montana statutes.

The 6-1 ruling is a major, and rare, victory for climate activists, who have tried to use the courts to force action on government and corporate policies and activities they say are harming the planet.

Montana’s Supreme Court has upheld a landmark climate ruling that said the state was violating residents’ constitutional right to a clean environment.

Montana's top court ruled on Wednesday the state's constitution guarantees a right to a stable climate and invalidates laws barring regulators from considering the effects of greenhouse-gas emissions when permitting fossil-fuel projects.

The ruling finds that youth have a "fundamental constitutional right to a clean and healthful environment".

The court agreed that the state’s energy policies violated Montanans’ constitutional right to a clean environment.