KALISPELL, MONTANA -- The day teenage brothers Lander and Badge Busse made history in the fight against climate change, they celebrated by fishing for trout under Montana skies clogged with smoke from wildfires.
"We've seen in our lives, particularly in the last five or six years, just kind of this infiltration of climate change and its effects into our own lives that we didn't ask for," said 18-year-old Lander.
"Nothing's improving at all," added Badge, 15. "It's getting worse. The smoke is getting worse."
The Busse brothers, not yet old enough to vote, joined 14 other young Montanans in suing their government for failing to protect them from the impacts of climate change. Last month, a judge ruled in their favor in a landmark decision that also found the state was complicit in the problem.
"We're just normal Montana kids. We're Montanans first," said Lander Busse in an exclusive interview with his brother at their family's home. "Although a lot of what we practice and preach are very rooted in what some might call environmentalist values, that's just how all of us have been living our whole lives."
Their victory in court -- the first of its kind in the country -- has been hailed as a turning point for the climate action movement.
State Judge Kathy Seeley concluded after a seven-day trial in May that a law forcing environmental regulators to ignore the impact of greenhouse gas emissions when evaluating permits for new energy projects violates the state's constitution.
Montana is one of just three states whose constitutional bill of rights explicitly guarantees the right to a "clean and healthful environment."
"We're very lucky to have that, and it hasn't been provided, and now frankly it's going to be," said Badge. "It's huge that she finally declared it."
Trial counsel Roger Sullivan, who represented the teens along with nonprofit advocacy group Our Children's Trust, said the ruling will have a tangible impact on the environment.
"If our state agencies and our state legislature responds to this in good faith, then we will see a difference on the ground in terms of permitting decisions and in terms ultimately of the amount of CO2 that's being discharged into our atmosphere," Sullivan said.
The case is also lifting the spirits of young people in four other states -- Hawaii, Virginia, Utah and Oregon -- with similar lawsuits pending against their governments over the climate crisis.
"Seeing such a landmark case kind of produce such an awesome result was really inspiring," said Layla Hasanzadah, one of 13 young plaintiffs suing the state of Virginia over climate change.
Isaac Vergun of Oregon, part of a long-running suit against the federal government for alleged failure to protect its citizens, said the Montana victory gives him hope.
"It's pretty plain and simple: the federal government has only known about this issue with climate change and has only exacerbated the problem," Vergun said. "This is all only going to create solutions."
State and federal governments have long rejected claims they bear legal liability for climate change impacts.
The Montana Department of Justice called last month's ruling "absurd" and a "publicity stunt," saying in a statement to ABC News that "Montanans can't be blamed for changing the climate."
Montana environmental officials said there is a good reason greenhouse gas emissions have never been part of their assessments: the law doesn't require it.
"The state legislature and the U.S. Congress have not said affirmatively, 'You shall go this way in a climate analysis,'" said Chris Dorrington, director of Montana's Department of Environmental Quality, which oversees permits for new oil, gas and coal projects in the state.
Dorrington declined to say whether the recent court decision, which is being appealed, would force his agency to consider global warming as part of its impact reviews.
"There's permits that have standards that are well vetted through really integrated stakeholder involvement of all sorts. We will permit according to those standards," he said.
The state's energy industry has downplayed the ruling, insisting it will do little to slow the development of Montana's fossil fuel resources.
"We can't just shut down the coal mines. We can't just shut down the oil and gas production. We can't just shut down the refineries. It'll put us into a tremendous economic downturn," said Alan Olson, executive director of the Montana Petroleum Association.
"The coal is still gonna be mined. We're still going to produce oil and gas. But [the decision] is going to give [environmental activists] a little more impetus to start filing more lawsuits," Olson said.
The court's decision notably stops short of ordering Montana to cut support for the energy industry or take steps to remedy the impacts from fossil fuel emissions.
Still, climate advocates say the symbolism of the case alone is highly significant -- a major validation of scientific evidence that climate change is real and that state policies make it worse.
"It really feels like the ball's starting to roll now," said Lander Busse. "There was a lot of skepticism about how much progress something like this would ever have in a place like Montana where fossil fuels dominate."
Montana's temperatures have been rising more than twice the global average, according to government climate data. And Judge Seeley's decision cited scientific evidence -- which went largely unchallenged by the state -- linking the warming to the promotion of fossil fuels.
"This gives legal foundation to putting [carbon dioxide] and greenhouse gasses into the mix of analyzing any of the permits," said Steven Running, a University of Montana climate scientist who won a Nobel Prize for his work on the Intergovernmental Panel for Climate Change and who testified against the state.
The oil, gas, and coal extracted in Montana led to the release of nearly 70 million tons of earth-warming carbon dioxide in 2019, Judge Seeley wrote, more than many major countries with substantially larger populations.
The decision declared Montana "a major emitter of greenhouse gas emissions in the world in absolute terms, in per person terms, and historically," noting that there is still a "significant quantity of fossil fuels yet to be extracted."
"It's a validation that none of the old climate denier stuff from 10 years ago was ever put forward," said Running. "I see the trial as a big step in giving people hope that we're starting to pay attention. The big global 'we'."
The Busse family says they are embracing that hope. But as the state begins its appeal of the case, the brothers say they're still grappling with the social costs.
"People in my school don't genuinely believe in climate change," said Badge Busse, who is entering tenth grade. "I'll probably be put in like a little box. I probably won't have that many friends this year."
Sara Busse, the boys' mom, says she and her husband Ryan, who's running for governor, see a bigger lesson for teens everywhere -- and their parents.
"We have to be willing to change. And, I mean, if we can't learn that from our kids, you know, I don't know who we can learn it from," she said.
The Busse brothers say the entire experience has motivated them to try to inspire others to take action to protect the wilderness they love.
"Not only is this a big deal for the establishment of our rights, but it's a big deal for the establishment of climate as a national problem," said Lander Busse.