A federal judge Monday dismissed President Donald Trump as a defendant in a case that a group of youth activists brought against the administration and eight federal agencies over climate change.

U.S. District Judge Ann Aiken, though, denied the Trump administration's motion to dismiss the case outright. It's set for trial Oct. 29 and estimated to last 50 days.

Twenty-one activists who hail from 10 states and range in age from 11 to 22 assert a constitutional right to a "climate system capable of sustaining human life.'' They contend the president and the federal agencies have violated that right and the public's trust.

They've asked the court to order the government to prepare a "national remedial plan'' to phase out fossil fuel emissions, draw down excess atmospheric carbon dioxide and then monitor compliance.

Aiken said she wasn't persuaded by the activists that suing the president was essential for their case. Lower-level government officials carried out the challenged policies, she noted.

"Due respect for separation of powers therefore requires dismissal of President Trump as a defendant,'' Aiken wrote.

Government lawyers had urged dismissal of the president with prejudice, meaning he couldn't be named as a defendant in the case in the future. But the judge refused to go that far.

"The court cannot conclude with certainty that President Trump will never become essential to affording complete relief,'' Aiken wrote. "Any harm the president will suffer from the continuing hypothetical possibility that he might be joined as a defendant in the future is minimal.''

In allowing the case to proceed to trial, the judge rejected several of the government's arguments.

Aiken dismissed government claims, for example, that the Administrative Procedure Act created by Congress is the sole method to challenge actions taken by federal agencies.

She cited case law from the U.S. Supreme Court and 9th U.S. Circuit Court of Appeals to find that challenges to federal agency actions can be brought either under the administrative act or through a constitutional claim, depending on the circumstances.

Yet the judge wrote that she recognized there are limits.

"Even should plaintiffs prevail at trial, the court, in fashioning a remedy, need not micro-manage federal agencies or make policy judgments that the Constitution leaves to other branches,'' she wrote.

Aiken also found that the young plaintiffs have provided sufficient evidence to argue that the government's actions over years contributed to harms suffered from climate change.

"The court is left with plaintiffs' sworn affidavits attesting to their specific injuries, as well as a swath of extensive expert declarations showing those injuries are linked to fossil fuel-induced climate change and if current conditions remain unchanged, these injuries are likely to continue or worsen,'' Aiken's ruling said. "Federal defendants offer nothing to contradict these submissions, and merely recycle arguments from their previous motion.''

Days before Aiken issued her ruling, government lawyers last week asked the 9th Circuit to halt the case pending U.S. Supreme Court review, a step they took previously that was unsuccessful.

"This suit is an attempt to redirect federal environmental and energy policies through the courts rather than through the political process,'' government lawyers wrote in their recent petition to the appeals court.

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian