A Montana judge's historic ruling in a climate lawsuit brought by 16 young plaintiffs could have implications for future climate litigation, legal experts say.

The trial and ruling, which came during a summer rife with crippling heat waves and other climate change-fueled disasters, was a rare win for climate activists seeking support in court.

It marked the first time a U.S. court has ruled that "young people have a fundamental right to a climate system that is safe and stable for their lives," said Julia Olson, chief legal counsel and executive director of Our Children's Trust. The nonprofit law firm represented the youth in the first-of-its-kind trial.

The case centered on a part of Montana's Constitution that guarantees the state's residents — current and future — "the right to a clean and healthful environment."

The plaintiffs — ages 5 to 22 — argued that Montana was violating that constitutional requirement by aggressively pursuing fossil fuel development without considering the future impacts to the state and the world's climate. State laws passed in 2011 and updated this year by the state's Republican-majority legislature prevented Montana agencies from considering climate impacts when permitting energy projects like coal and natural gas.

First District Judge Kathy Seeley rejected the state's argument that its contributions to global warming were inconsequential in comparison with other sources. She found the state's prohibition on even considering the long-term impacts of fossil fuel development as "unconstitutional on its face."

The ruling is a paradigm shift in climate litigation, a fast-growing field of law, Olson said, that will "have a ripple effect across the world."

Other legal observers agree.

"I thought this was one of the strongest decisions on climate change issued by any court anywhere," said Michael Gerrard, director of Columbia Law School's Sabin Center for Climate Change Law. "In every respect, the court agreed with the plaintiffs that fossil fuel combustion is the main cause of climate change and [that] climate change is having all kinds of terrible health and environmental impacts which will get worse unless we stop those emissions," he said.

Montana, one of the nation's largest coal producers, has said it will appeal the ruling to the state's Supreme Court.

Regardless of the appeal, legal observers say the victory could influence future court cases that look at government culpability in the worsening climate crisis. The number of climate-related lawsuits around the world has more than doubled over the last five years, according to a recent report from the United Nations. "As these cases become more frequent and numerous overall, the body of legal precedent grows, forming an increasingly well-defined field of law," the report states.

Legal experts say the 103-page ruling from Seeley is particularly helpful because it adds so much climate science to the record. More than 70 pages of the ruling list factual findings that could be cited in future trials.

"Nationally, I think a case like this is what sets the stage for the dominoes to fall and for other courts to look at this really detailed ruling from the judge in Montana and say, 'Yeah, we've got something similar going on, and we're not charting new territory now,'" said Barbara Chillcott, a Montana-based attorney who worked on the case for the Western Environmental Law Center.

In an emailed statement, Emily Flower, a spokeswoman for Montana Attorney General Austin Knudsen, called the ruling "absurd" and "a taxpayer-funded publicity stunt."

The state's argument has long been that Montana — a state of just over 1 million people — can't be blamed for changing the world's climate. Its contribution to human-caused climate change, which has already warmed the planet nearly 2 degrees Fahrenheit, has been inconsequential in comparison with other sources, the state argued.

Twenty-two-year-old Rikki Held, the lead plaintiff in the case, said the ruling confirms what scientists have been saying for decades.

"For us to have this come to trial and have this science-based evidence in the court record and having decision-makers listen to us is just really amazing," she said. "This case can set a precedent for other legal cases outside of Montana's borders."

The relative uniqueness of Montana's Constitution, which guarantees residents the right to a clean environment, could limit the ruling's usefulness in other states, legal experts say. A handful of other states do have similar language — most notably Hawaii, where Our Children's Trust is engaged in another youth-led climate lawsuit.

"In those states, the court's framing in [this ruling] will be particularly salient, even though it's not binding," said Julia Stein, an environmental law professor at the University of California, Los Angeles.

The Hawaii case, Navahine F. v. Hawaii Department of Transportation, will go to trial next summer. Our Children's Trust also has cases pending in Utah, Virginia and, soon, Florida. While trials and rulings are still rare for climate litigants, legal experts say the Montana ruling is meaningful in that it shows courts can be a useful tool for reducing climate-warming emissions.

"It's not a silver bullet," Gerrard said. "But we need a lot of silver buckshot, and litigation, certainly, is one important element of that."