An 18-year-old from Kalispell concluded testimony from the 16 youth plaintiffs and expert witnesses in the Montana climate change trial Friday by excoriating the state government for what he said has been decades of ignoring science and for trying relentlessly to stop him and the other plaintiffs from having their day in court.

“I don’t know how you can sit in this courtroom and listen to everything that is put on display here and not have a semblance of regret or even responsibility to get up and fix these things we have been told firsthand can be fixed,” said Lander Busse, one of the older plaintiffs suing the state and several of its agencies alleging its policies violate their rights under the state constitution to a clean and healthful environment.

Busse said he and other plaintiffs felt it had been “a really hard week” in court as they listened to several climate, mental health, and policy experts explain what the state of Montana could consider when it comes to climate change that it has instead written into law to ignore under the Montana Environmental Policy Act limitation.

“It’s been really difficult to watch how dire of a situation this is be put on full display,” Busse said. “Equally as frustrating is knowing the place we’re in as a state to be able to stop these problems.”

Busse said the presentations this week from the expert witnesses as well as his fellow plaintiffs have reinforced their feelings that Montana’s climate has been changing over their lifetimes because of the effects of Montana’s decades of permitting and fostering fossil fuel energy development. He said the state’s positions, and many efforts to have the case dismissed, have also reinforced how he feels about its efforts to do anything to change its stance.

“I can’t speak to the exact emotions of Gov. (Greg) Gianforte or Attorney General (Austin) Knudsen toward our case. The statements toward our case and everything we’ve worked so hard for these past three weeks have been disrespectful, vicious, wrong and completely disregarding what this state and its constitution were initially ratified for,” Busse said. “I’m very disappointed, but this may be some catalyst for change.”

Busse is an avid outdoorsman, hunter, fisher, singer and actor who is headed to the University of Denver later this summer to study vocal performance on a scholarship. Like all the other plaintiffs who have testified this week, he said the smoky air every summer, warmer air and water temperatures year-round, and changes to the landscape he holds dear has affected both his physical and mental health – a key argument in the plaintiffs’ case.

“Thank God it’s Montana that gets here first (to the trial) because I can’t stand to see this place I and so many people view so dearly be put to such waste at this point,” Busse said.

His testimony Friday afternoon followed that of Lise Van Susteren, a physician and psychiatrist who studies the effects of climate change on children’s mental health, and Mark Jacobson, an environmental and energy expert and modeler who testified about what it would take for Montana to move to 100% renewable energy during the next few decades – something he said was entirely feasible if policymakers decide to take that route.

Jacobson, the director and cofounder of the atmosphere and energy program at Stanford University, has for years been updating a model that started as one to study air pollution in Los Angeles as his Ph.D.- dissertation, out of which he built models to find out what it would take to transition all 50 states and more than 130 countries to full renewable energy by 2030 and 2050.

He told the court how using data from the Energy Information Administration he put together a model for Montana and other states to have their energy consumption be fully renewable energies.

Jacobson said about 75% of Montana’s energy consumption in 2018 came from fossil fuels, while around 21% came from wind, water and solar energy. Currently, he said, Montana can get 92% of its energy from wind, water and solar energy – most of which is consumed through transportation and buildings.

Further, he said, Montana has “no limitation” on how much renewable energy it could produce because of its vast land mass, the wind that blows through the state – Montana has 330 times the wind energy potential that it needs to power the entire state, he said – and the amount of sun it receives, especially in summer. He said the state could use a fraction of the land it uses for fossil fuel production to install around 1,000 wind turbines that he said could push the state to be able to utilize 100% renewable energy.

But he said Montana’s policies have pushed it away from doing so.

He said the state could instead be promoting switches to electric vehicles and farm equipment, or those that run on hydrogen cells, and could be moving away from natural gas toward electric heat pumps and induction cooking ranges. But lawmakers in this spring’s legislative session passed several bills explicitly prohibiting local governments from banning the use of fossil fuels in building codes, from banning the purchase or use of fuel derived from petroleum, and from requiring new construction to add solar panels.

“It slows down a transition or even prevents a transition,” Jacobson said.

He said the opposition to move toward renewable resources by the state is costing it, and its taxpayers, billions of dollars each year. He said Montana is estimated to spend about $9 billion a year for all of its energy sectors if nothing changes, but that switching to fully renewable energy would only cost $2.8 billion a year.

Further, he said, while the upfront costs to switching to electric vehicles and electric appliances would be significant, the government could do what the federal government is and provide people with subsidies to encourage the switch. And he said that moving away from fossil fuels in the long run would save billions in the long run.

He said switching to electric vehicles would save Montanans $30 billion during the next 15 years because of gasoline and maintenance costs, about $1.7 billion a year in health costs because of greenhouse gases and pollution, and annual climate costs of $29 billion a year because of the various negative effects of greenhouse gas and carbon emissions.

He said his models show reducing pollution in Montana would “immediately” and in the long term reduce health impacts for Montanans and that a broader effort by states and countries to eliminate greenhouse gas emissions, if done by 2030, could allow the planet to move back to the targeted goal of 350 parts per million of carbon dioxide in the atmosphere by 2025 – a broad goal among climate scientists and others in the scientific community.

And as the state naturally transitions to more renewable energies as prices for materials and energy storage continue to decrease as they become more prevalent, Jacobson told the court and the attorney for the state who cross-examined him, that moving away from fossil fuels was the only thing that made sense to benefit the environment, Montanans, and the state’s pocketbook.

Pushing back against state attorney Mark Stermitz, Jacobson said Stermitz was “talking trivialities” when trying to find ways to tell Jacobson that transitioning away from fossil fuel-based energy was not feasible in Montana, and said the state has the complete ability to do so and realize those savings and benefits – but only if it so chooses.

“I do science; nobody listens to me. But working together with other people is how we affect change. I provide information on the work we’ve done, but it requires collective willpower,” Jacobson said. “Policies are needed to affect this transition.”

Van Susteren, the psychiatrist, said while she had not examined or diagnosed any of the plaintiffs, it was clear from their testimony this week and written statements that they are experiencing negative mental health effects because of human-induced climate change.

She explained how her research and other scientific studies have consistently shown that extreme weather events like wildfires, flooding, and drought can have lifelong lasting physical and mental health effects in humans and how children are the most sensitive group because their bodies are still developing. She said today’s youth, including the plaintiffs in the case, will be subjected to seven times the number of extreme weather events as current adults will experience.

Those repeated events create the most stress, anxiety and physical and psychological harm to children during their lifetime, and can down the road turn into serious health effects like heart problems, Parkinson’s disease, dementia, serious mental health disorders, suicidality, anxiety and depression.

“Professionals like me are seeing this in many professional practices and, of course, seeing it in the literature,” she said.

She said she has seen negative psychological health effects worsen during the past 15 years, and that the younger generation is very attuned to the facts of climate change because they are “suffering consequences that are spinning out of their control.”

Van Susteren explain that the latest Intergovernmental Panel on Climate Change report, referenced many times this week, found with a very high degree of confidence that climate change was having “detrimental impacts … on mental health.”

Asked if there was scientific consensus that climate change can harm people’s mental health and especially that of children and young adults, she responded: “Indisputably.”

After detailing the testimony of most of the plaintiffs who took the stand this week and discussing how she believes their mental and physical health is being compromised by climate change, Van Susteren also discussed how the MEPA limitation – which says Montana cannot consider greenhouse gas emissions or the impacts to the climate when considering environmental project permits – is contributing to the plaintiffs’ alleged injuries.

She brought up the term “institutional betrayal,” in which governments that are responsible for protecting their people violate what she said is a “social contract” to do so. A paper she published in 2021 with others in the medical journal The Lancet that studied 10,000 people ages 16-25 in 10 countries found half believed climate change was affecting their daily lives and two-thirds of them believed the government’s lack of action was to blame.

“Here we have an instance where it is the power of the state to take care of these children, to protect them,” she said. “Instead of protecting them, they’re increasing the dangers.”

She said there was only one remedy for the injuries the youth are suffering – “to address the root cause.”

“It’s the promotion of fossil fuels and the ruling within the state that expressly prohibit consideration of climate impacts,” Van Susteren told the court.

Busse would shortly afterward share a similar sentiment when concluding his remarks about the case, the trial, and what he says is the state’s responsibility.

“The state has one job: To look out for us,” he said.

The trial will continue Monday in Helena but is unlikely to last through all of next week, as was allotted. Attorneys for the state said Friday morning they would not be calling controversial climatologist Judith Curry to the stand, whose testimony the plaintiffs’ attorneys had asked their expert witnesses to rebut in testimony this week.

They also said at the end of the day Friday they did not believe they would take the full week with their list of witnesses. Assistant Attorney General Michael Russell told Judge Kathy Seeley that the state plans to call heads of agencies, including the director of the Montana Department of Environmental Quality, to the stand to start the day Monday.