The benefits show up not only in the bottom line—according to a recent survey by marketing and advertising firm WPP Group, consumer spending on green products will hit an estimated $500 billion next year—but also in brand loyalty. “People want to be part of this movement, and they want to brand themselves part of this movement,” says Mike Hughes of the Martin Agency, a marketing firm that works with Al Gore’s Alliance for Climate Protection and the Discovery Channel’s new eco-awareness channel, Planet Green. “They feel better about showing up in a hybrid Lexus than an ordinary Lexus . . . The conventional wisdom used to be that people wouldn’t buy things because they were green. People wouldn’t pay extra for green items.”

That’s no longer the case, which is why, in a survey by business advisory firm Grant Thornton, 77 percent of companies said they anticipate spending more on environmental sustainability programs in the next several years.

“There is a new luxury marketplace out there,” says Loudermilk, who has created a Luxury Eco Stamp with the aim of “certifying” the most responsible luxury brands for a range of given products. Last year’s “stamped” companies include London-based Nick and Milly’s, which makes vegan bath and body products, and Living Homes, which builds houses using green materials. This year she’s considering stamping Louis Vuitton for its veg-tan handbag line, which is tanned using vegetables. If companies don’t continue to make green fun and sexy, she says, “it’s going to die as the hippie movement did.”

Of course, it’s an open question how much consumers are really helping the environment by choosing green luxury goods. Lloyd Alter, a staff writer for the popular website TreeHugger.com, is skeptical about green marketing: “The best thing for the environment is if they all just consume less.”

Celente agrees. “A lot of the green is glitz to make people feel good, as though they’re doing something. If these people are so concerned, we’d be hearing about things they’re doing to turn the environmental tide in very large ways [other] than [buying] luxury items.”

But green luxury will continue as long as it results in—well, green. The first luxury hybrid, the Lexus RX 400h, has sold more than 50,000 units since its launch in 2005. Silverjet is expanding with flights to Chicago and Los Angeles and is planning to eventually offer a total of 30 global routes.

“Some people might be cynical,” says Allen Hershkowitz, a senior scientist at the nonprofit Natural Resources Defense Council. “The point is, everybody has to do something, given the nature of the eco-crisis we’re facing. We have to make those luxury goods less of a footprint. [The recycled] labels on vodka bottles matter.”