A 19-year-old college student from Oregon was suing Barack Obama in hopes of saving the world. Now that Obama is out of office, she’s turning her lawyers loose on Donald Trump.“Trump,” said Tia Hatton, “is scary. He’s terrifying.”

On Thursday, the young people asked their lawyers to go to court and substitute Trump for Obama as the defendant in their 2-year-old lawsuit, which could come to trial in federal court in Oregon this year. In November, a federal judge denied a U.S. Justice Department motion to have the case dismissed.

Hatton came to San Francisco to explain the suit as the guest of the prestigious Commonwealth Club.

“The government just isn’t doing its job,” Hatton said in an interview. “The government knows about climate change. They knew about the science. They’re infringing on everyone’s rights.”

On the campaign trail, Trump called climate change a hoax. The president’s willful dismissal of scientific consensus is worth battling in court, Hatton said. She and the other plaintiffs, ages 9 to 20, say fouling up Earth violates nothing less than their constitutional rights.

The future is in such jeopardy, Hatton said, that she isn’t sure she wants to have a family.

“I’m fearful of bringing children into the world,” she said. “I’m not sure. I’m scared.”

Many courtroom showdowns have been called the Trial of the Century, but Hatton and her lawyers, who include Philip Gregory of the firm Cotchett, Pitre and McCarthy in Burlingame, say that with the fate of the planet hanging in the balance, this one may live up to the hype.

Gregory said he is basing his case on the Boy Scout principle.

“When you’re a Boy Scout,” he said, “you’re supposed to leave your campsite cleaner than you found it.”

Hatton and her fellow plaintiffs hope the court forces the government to impose limits on fossil fuels and to develop alternative energy sources, in much the same way as courts ordered the government to integrate schools more than half a century ago. They want the court to order reductions on greenhouse gas emissions, halt new oil drilling and end the reliance on nonrenewable energy sources.

The case relies on the legal notions of public trust doctrine and substantive due process. The first means that the government must preserve public resources. The second means that the government can’t deprive people of life, liberty or property without due process. Were a citizen to drown when rising waters flooded his home, he would be deprived of all three at once, the lawyers say.

Hatton acknowledged that the world may not be ready to drop fossil fuels cold turkey just yet. On Wednesday, she acknowledged, she flew from Oregon to San Francisco International Airport and rode in a car from the airport to San Francisco. Both vehicles burned fossil fuels.

“We can’t lead zero-emission lives yet,” she said. “We’re all still part of the system.”

Steve Rubenstein is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: @SteveRubeSF