Montana youths win climate lawsuit against state for promoting fossil fuels

A group of young people from Montana won a major climate case on Monday after arguing the state failed to protect their right to a clean environment by continuing to use fossil fuels.

The ruling determined that a provision in Montana's Environmental Policy Act violated the right to a clean environment, which is guaranteed under Montana's state constitution, by promoting the continued use of fossil fuels.

The court said a provision in the law that prevented the state from considering the climate impacts of energy projects is unconstitutional.

"In a sweeping win for our clients, the Honorable Judge Kathy Seeley declared Montana's fossil fuel-promoting laws unconstitutional and enjoined their implementation," Julia Olson, chief legal counsel and executive director of Our Children's Trust, said in a statement.

Sixteen Montana youths between the ages of 5 and 22 sued the state, the governor, the Montana Department of Environmental Quality, the state's public commission office and other state departments in 2020 over Montana's fossil fuel-based energy system, citing scientific evidence that burning fossil fuels is contributing to global warming that already causes them harm, according to the lawsuit.

The judge's order cited the scientific facts presented by expert witnesses that there is overwhelming scientific consensus the Earth is warming as a direct result of greenhouse gas emissions, primarily from burning fossil fuels. It also laid out evidence that Montana's temperatures are expected to increase and that increased impacts of climate change, such as heat waves, have adverse impacts on young people's mental health and quality of life.

Judge Kathy Seeley wrote that Montanans have "a fundamental constitutional right to a clean and healthful environment, which includes climate as part of the environmental life-support system."

"Youth plaintiffs have experienced past and ongoing injuries resulting from the state's failure to consider [greenhouse gas emissions] and climate change, including injuries to their physical and mental health, homes and property; recreational, spiritual and aesthetic interests; tribal and cultural traditions, economic security and happiness," Seeley said.

The decision is based on a unique provision in the Montana Constitution that guarantees citizens a "clean and healthful" environment. At least three other states -- Pennsylvania, New York and Hawaii -- have similar constitutional language.

There are similar challenges underway in those states, and the Montana decision will likely be appealed.

Effective immediately, Montana officials will be required to consider the impacts of greenhouse gas emissions when making decisions for oil, gas, coal and other energy permitting. Currently, state law forbids them from considering those impacts.

Montana officials said during the trial in June that if the plaintiffs won their case, it would not change approvals for fossil fuel projects, according to The Associated Press.

"We do not have the authority to not permit something that fully complies with the law," Department of Environmental Quality Director Chris Dorrington said, according to The AP. "We are the ones that implement the law. We are not the ones that create the law."

"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," Olson said in a statement. "This is a huge win for Montana, for youth, for democracy and for our climate. More rulings like this will certainly come."

Another youth climate case against the Hawaii Department of Transportation is scheduled to go to trial in Hawaii next summer.

ABC News' Devin Dwyer contributed to this report.