A DECADE LATER, Steger is hanging out in a tony Los Angeles neighborhood—not a place you'd expect to find him. Just now he's sitting lotus style on the floor of former supermodel Cheryl Tiegs's Balinese-style living room, listening to Frank Sinatra sing Christmas carols and watching Tiegs, Theo, and a few other guests trim the tree while he shoots the breeze with actor Ed Begley Jr.

Begley is one of Hollywood's original greenies. He lives in a solar house, drives an electric car, and has a new television show, Living with Ed, that debuted on the Home & Garden network in January.

"Living with Ed is basically about what it's like to live with an environmental zealot," Begley tells Steger. "It's like a 21st-century Green Acres."

"The show is great," says Rachelle Carson, Begley's co-star and wife. "If I can go green, anyone can."

"Even Danny DeVito solarized his house," Begley adds. "Everyone wants to take action."

Steger nods, but I have to wonder if he's ever heard of Green Acres or Danny DeVito. Theo, on the other hand, seems ready to give the environment a rest. Earlier, he discovered a new gadget in Tiegs's kitchen. ("Is this one of those iPods that everybody's talking about?") Now he's engrossed in his first-ever tree trimming, which is one tradition Catholic missionaries didn't force on the Inuit, given that there are no evergreens where Theo grew up.

This is Steger's third trip to L.A. in five months, and he's finding the SoCal lifestyle agreeable. "It's sort of like a vacation," he told me on the ride over. "I never paid attention to Hollywood. In fact, a lot of times I don't know who I'm meeting. But I like the attitude, and it's an engine for change.

"Plus," he adds, "it's fun."

Steger has pressed flesh before—in the eighties and nineties, he spent a lot of time in Washington, D.C., working with Al Gore and the Wilderness Society on issues like Arctic preservation—but Hollywood is a different world. The fact that he's here, eating steak with the stars, involves a curious convergence of events, starting in 2002 with the breakup of the Larsen Ice Shelf, which he'd traversed in 1989. Such signs of climate change dovetailed with his increasing irritation with the Bush administration, which, in his view, showed little interest in taking a serious look at global warming.

"The president was doing nothing about the environment," says Steger. "It was making me angry. I started to feel negative, and I can't live with negativity."

Finally, in 2003, Steger had a fateful lunch in St. Paul with fellow Minnesotan and explorer Dan Buettner, who invited him on an expedition to retrace the frankincense route through the Middle East. That never happened, but the conversation inspired Steger—who'd been cooling his heels for years at the Homestead, reading, writing, woodworking, and mounting small-scale expeditions—to get back in the game. In January 2006, he created the Will Steger Foundation, an environmental nonprofit based in Minneapolis.

"Will eats, breathes, and sleeps global warming," says Buettner. "He's hardwired to thrive with a sense of purpose. His resurgence has been like Lazarus rising from the grave."

Buettner had a few contacts in Hollywood, starting with his longtime girlfriend, Cheryl Tiegs. Tiegs had met Steger years before and was excited to introduce him to friends.

"In Hollywood, we're just talking about global warming and thinking about it and wondering about it," Tiegs tells me. "We're not particularly living it. Will is our conduit to the people who are really going to suffer. What he's doing is unique."

The fun at Casa Tiegs winds down before midnight, at which point Steger slips outside to a chaise lounge at the edge of the swimming pool. Tiegs has given Steger the run of her house, but, true to form, he prefers sleeping under the stars.