The Animal Legal Defense Fund sued Monday to compel the federal government to act on climate change as a similar lawsuit filed by a group of young activists is on hold.

The plaintiffs include scientists, nature enthusiasts and wildlife advocates who say they fear for their safety because their research or interactions with nature are hampered by increased severity of wildfires, mudslides, flash flooding, avalanches and disappearing snowpack and edible native plants.

They contend they have a fundamental right to be left alone "free from human interference'' in the wilderness.

They're asking a federal judge to declare that the U.S. government is violating that right by contributing to a dangerous concentration of greenhouse gases in the atmosphere.

Among them is Michael Goetz of Portland, an Animal Defense Fund member who recounted in the suit waking up on a backpacking trip to wildfire smoke that was so intense he couldn't see his hand in front of his face.

Another is wilderness guide Cody Shotola-Schiewe of Portland who said he's faced increased rock fall and avalanche dangers on Mount Hood climbs. Portland resident Ian Petersen is an avid backpacker who bemoaned the "growing number of bad air days'' from fire smoke that have cut short his hiking trips in Oregon, according to the suit.

Will Gadd, an outdoor adventure athlete who recently became the first to climb a frozen Niagara Falls, is also a plaintiff.

"He has witnessed ice and glacier melt while climbing in conditions that are much more dangerous today than they were years ago when he first began climbing,'' the suit says. "Will is harmed by the government's actions and inactions to stem the severity of climate change because he is prevented from reasonably and safely exercising his right to wilderness on which he relies for his physical and mental well-being as well as his global status as an outdoor adventurer and educator.''

The lawsuit names the U.S. Department of Interior, the U.S. Department of Agriculture, the U.S. Environmental Protection Agency, the U.S. Department of Defense and other agencies.

The new suit comes just days after the U.S. Supreme Court temporarily blocked a high-profile climate change lawsuit that 21 young activists brought against the federal government in Eugene.

That lawsuit alleges the government has violated young people's constitutional rights through policies that have caused a dangerous climate.

Chief Justice John Roberts' order on Friday freezes trial proceedings, which were due to start Oct. 29, and gave lawyers for the young activists until Wednesday to provide a response. The U.S. Department of Justice had asked the high court to dismiss the case, saying political process, not the courts, should address the issue.

The new lawsuit takes a different approach, said Carter Dillard, the Animal Legal Defense Fund's senior policy adviser and one of the attorneys involved in the case.

While the first suit focuses on constitutional rights to life, liberty and property and protection of public trust resources, this one focuses on "the simple right to be let alone, the right long recognized and protected under banners like privacy and liberty," Dillard said in an email.

"The right to be let alone has been protected in the context of things like freedom from state surveillance and the government's intrusion into our bodily autonomy," he said.

"The Constitution certainly has to account for threats to national well-being and continuity, like climate change, and we think the jurisprudence on privacy and liberty is one place where it accounts for that threat," he said. "How could the government shirk it's most basic responsibility, and argue otherwise?"

-- Maxine Bernstein

mbernstein@oregonian.com

503-221-8212

@maxoregonian