YOU EXPECT Chip Giller to be hilarious. He's not, and maybe that's for the best.

I've been invited to break bread—and dip hummus—with Giller at his 1908 farmhouse, perched above Quartermaster Harbor on Vashon Island, a rural bedroom community a half-hour ferry ride from downtown Seattle. This afternoon there's a full table: Giller, his wife, Jenny, their infant daughter, Ellis (swaddled, naturally, in Seventh Generation chlorine-free diapers), and Ellis's godmothers, Abbie and Ilene, who drove up from Portland for a surprise visit. The conversation skips lightly from only-in-Seattle concerns—everyone at the Gates Foundation, where Jenny works, is stressed about giving away enough money to meet fourth-quarter goals—to embarrassing tales of Giller's childhood. Like how he used to write "Property of Future Senator Charles M. Giller" on his lunch bag, or the time in seventh grade when he dressed for Halloween as his idol, then–Massachusetts governor Michael Dukakis.

The stories make sense. For a guy trying to cast himself as a new type of enviro, Giller—with his moss-hued Dieter glasses, flannel shirts, Ecco shoes, and winsome smile—is surprisingly, conventionally … crunchy.

Raised in brainy Lexington, Massachusetts, he grew up reading Bloom County and his father's copies of the Columbia Journalism Review. (Both his parents are serious news junkies.) By his freshman year at Brown, in 1989, his precocious wonkiness had taken on a deep-green hue. He grew his hair into a voluminous mane and embarked on quixotic crusades: scolding a housemate for wasting energy by plugging in his answering machine, lobbying the geology department to illuminate its prize moon-rock display with fluorescent bulbs, and carrying around all the weekly trash generated by a typical student in a clear plastic bag in order to shame his classmates into consuming less. "It wasn't very persuasive," he admits.

After graduating in 1993, he worked for eight months as a reporter at High Country News—the Paonia, Colorado–based biweekly that's emerged as the environmental newspaper of the West—then moved to Washington, D.C., to take a job at Greenwire, a technocratic policy newsletter. Giller and his cohorts would scour the dailies for stories, synthesize them, then fax bulletins to congressmen and agency bureaucrats. In short order, he became Greenwire's editor, but after three years of bone-dry policy coverage, he decided he wanted to start something "more accessible to the average Jane or Joe."

The year was 1998, the Internet had exploded, and Giller convinced Denis Hayes—an organizer of the original Earth Day in 1970 and one of Giller's reporting sources—to buy into his vision. Hayes raised several hundred thousand dollars to incubate what would become Grist at the Seattle offices of the nonprofit Earth Day Network. On April 17, 1999, Giller sent the first Grist e-mail digest out to 100 of his and Hayes's closest friends, who just happened to include Bill McKibben, Phil Shabecoff—a former New York Times environmental writer who published Greenwire—and many other green bigwigs.

The list grew—to 1,000 that September, then 10,000 the following June. In 2003, a $600,000 grant from the V. Kann Rasmussen Foundation allowed Grist to spin off as an independent nonprofit. The site has since scaled its readership by a factor of ten and now reaches millions more through weekly online syndication partnerships with MSNBC and Salon. Meanwhile, Giller has convinced a dozen foundations, including Ford, Geraldine R. Dodge, and the Schumann Center for Media and Democracy, to underwrite roughly 85 percent of Grist's operating costs.

In short, a serious operation founded by a serious guy. So where did the humor come from? From Giller, though that wasn't the original plan. He wrote the goofy headlines for the first e-mail in the middle of a rainy night, when he was exhausted. "I was just slap-happy," he says.