QUECHEE, Vt. — Living green is not for the faint of heart. Think of the imponderables. What roach killer should one use? How should one deal with environmentally oblivious in-laws? Can one generate electricity while exercising on a StairMaster or a stationary bicycle? Why is bisphenol-A — a chemical found in children's sippy cups and other plastic containers — considered a toxic villain by some but not by the Food and Drug Administration?
Confused? Ask Umbra, the arch online sage of the new green age. A trailblazer in the field of eco-advice columnists, Umbra Fisk serves as a sensible big sister to the growing tribe of the environmentally aware. She teases, informs, puns and prods, but never scolds.
Six years after its inception, "Ask Umbra," a twice-weekly column that reads like the love child of "Miss Manners" and "Car Talk," is the most popular feature of the environmental Web site grist.org.
Want to rid the house of roaches? "Catnip is a natural repellent, as is an inedible fruit called a hedgeapple," Umbra wrote. "You can place these in known roach hot spots, sit back and watch the diaspora."
"Umbra's Studio," an online video program based on the columns, should make its debut this fall. Oh, yes, one other thing — she does not really exist.
Becka Warren, who writes for grist.org from Vermont, drafts most of Umbra's columns. Was the name a play on her own mysteriousness? Ms. Warren says it "just came into my head" back in early 2002 when the founder of grist.org, Chip Giller, was brainstorming about an advice column. The first installment appeared that year.
Umbra now has a supposed dwelling place (the basement library at the magazine's offices in Seattle) and a virtual social life (Arianna Huffington, the doyenne of Los Angeles's political left, says she is a great dinner guest — "during the cocktail hour she disappeared and made all my toilets low-flush.")
Whether real or virtual, Umbra Fisk has been a trend-setter. Similar columns, blending authority and insouciance, have popped up elsewhere, including "Ask Pablo" on Salon.com, "Green Lantern" on Slate.com, "Earthtalk" on E Magazine's site and "Mr. Green" on the Sierra Club's Web site.
The writers "have all come out of environmental science programs, and this is a common language of their culture," said Kevin Berger, the editor for environmental coverage at Salon.
"Not only are they environmentally committed and passionate about conservation and global warming," Mr. Berger added, "but they know the math and the science behind it. That gives them this easygoing authority, which the proselytizers of yore don't have at all."
"Ask Umbra" was one of the first such columns. Grist.org has about 750,000 unique users monthly, said Mr. Giller, who said that more than half a million site visits this year hit on "Ask Umbra" — not counting traffic on the online network MSN and The Huffington Post Web site, both of which carry Umbra.
Umbra Fisk's no-nonsense, no-embarrassment voice resonates with the left-leaning people in their 30s who were the first generation to take environmental studies for granted as a part of a college curriculum. Judging from the questions, the readers, like Umbra's creators, are forming families (or choosing not to), buying cars (or choosing not to) and having babies (or choosing not to). Her view on the old argument about cloth versus disposable diapers? A tossup, environmentally speaking.
The readers also appreciate frankness about everything from phosphates to condoms, and a knowledgeable voice on questions about atmospheric science and shower urination (is it more environmentally correct than using a toilet?) .
Here, for example, is Umbra's take on yoga mats: "They seem so soft and friendly, but they are another product for our list of Things That Contain Vinyl. Vinyl and phthalates. How I wish to never need spell phthalates again." She suggested a jute and rubber alternative.
She also assures the party set that yes, you can recycle a beer bottle with a lime in it.
In two judgmental businesses — advice-giving and environmentalism — Umbra strains to be nonjudgmental. "I don't want to be mean to people," Ms. Warren said in between bites of a pulled-pork sandwich, after a morning of picking potatoes as part of her commitment to sustainable farming.
Umbra, however, makes an exception to that rule when dealing with judgmental environmentalists. Answering a reader who complained about having to take her baby to the home of in-laws who were oblivious to the perils of polyvinylchloride and peeling paint, Umbra wrote, "Your expectations for your in-laws are clearly unrealistic," adding, "If you explode, you will prove yourself to be a freak dog of a first-time parent."
Ms. Warren comes as close to an alter ego as Umbra has, though some of the credit for her public persona also goes to Mr. Giller; to a grist.org editor, Katharine Wroth; Jennifer Prediger, an actress living in Brooklyn; and a Web video producer, Stefanie Syman.
Ms. Warren, 37 and a graduate of Brown University, is married to a graphic novelist and is the mother of a 2-year-old daughter. They live on a farm.
She buys things like furniture second hand but worries that her lack of enthusiasm about consumer goods — she is not part of the mall-and-Starbucks set — may distance Umbra from mainstream American life. Ms. Warren said she grew up with "Yankee thrift" and knows little about the kind of life "where you have a ton of stuff and a new house and you go and buy new furniture."
Nonetheless, she is determined to upend the environmentalist stereotype: "A scolding person with no fashion sense — that's not who we are."