“It has been said that a pretty face is a passport,” the British columnist Julie Burchill once wrote. “But it’s not. It’s a visa, and it runs out fast.” Burchill’s wisdom also applies to fashion, the trendiest of industries, which is currently being seduced by the trendiest of buzzwords: ­sustainability. The spring 2008 Louis Vuitton ad campaign, featuring wizened rocker Keith Richards and other celebrities, proudly declared its support for Al Gore’s Climate Project. This past Christmas, luxe retailer Barneys New York used the slogan “Have a Green Holiday” and promoted a fully recyclable Goyard canvas shopping bag. Ralph Lauren now sells organic-cotton home linens. (View slideshow.)

At first glance, these efforts seem quite noble. But Vuitton sells $5 billion worth of luxury handbags, scarves, sunglasses, and suitcases annually, reaping close to $2 billion in profit—yet its support of the Climate Project amounts to persuading its celebrity endorsers to donate their fees. The Goyard bag was more ostentatious than eco-conscious, retailing for $1,065 (plus $310 for a gold-painted recycling logo). And those ­organic-cotton sheets are made by a company that sells more than $1 billion a year through nonstop rollouts of new designs that render fashions outmoded within months.

So waif-thin are couture’s green “efforts” that the World Wildlife Fund admonished those in the fashion industry for being “slow to recognize their responsibilities and opportunities” in environmentalism. In a January report, investment research firm Innovest’s list of the 100 most responsible corporations included no luxury conglomerates—a glaring omission, given its nod to such unlikely environmentalists as Alcoa, Disney, Hewlett-Packard, and Nike.

Innovest’s list, oddly, does include two leading retailers in the wasteful “fast fashion” movement—H&M and Inditex, which owns the Zara chain. It’s hard to be truly green with a business model that compels customers to frequently throw out what they own. Unfortunately, luxury fashion has begun taking cues from fast fashion, putting itself at odds with its exclusive nature. Whereas couturiers once made design statements as part of an ongoing evolution—creating new jackets that would go with last year’s dresses—fast fashion introduces clothes nonstop, zigzagging through multiple styles each season. Forced obsolescence drives consumers to buy more. This may sound like a shrewd business practice, but overproduction leads to overconsumption: The more we buy, the more we discard. That’s environmentally heedless—and it’s ugly.

Luxury companies like Gucci and Prada once operated as small, family-run businesses, selling simple designs in limited editions. In 1977, Vuitton, with just one store in Paris and another in Nice, took in the present-day equivalent of $50 million. Such companies didn’t overproduce for outlets; unsold goods stayed on sale.

But as these labels have become publicly traded global conglomerates—Vuitton is now a 390-store empire—such artisanal strategies have become, well, unsustainable. Luxury fashion is a $200 billion category, by some estimates, and LVMH head Bernard Arnault predicts rapid growth in robust markets like China, India, and Russia. Dressing luxury in an eco-friendly gown demands eco-unfriendly practices. The typical Western-designed handbag is assembled in China, trucked to Hong Kong, and shipped to Italy—where the attachment of a buckle or handle is enough to earn the vaunted made in italy label—before it is flown back to China to be sold. No public image is green enough to offset that kind of carbon footprint.

Such waste has sparked a slow-fashion backlash, which, echoing the movement for locally grown food, recalls strategies used by the dominant luxury brands before globalization engorged them. One slow-fashion leader is Slowear, a company of four Italian manufacturers sharing a mission to make beautiful items with natural materials, sensitive dyes, and low-emissions production. And in June, Italian luxury label Loro Piana announced it had bought nearly 2,000 acres in Peru to preserve the vicuña, a cousin to the llama prized for its expensive fleece, in an investment that’s unlikely to pay off for years.

Multibillion-dollar labels that answer to shareholders can’t adopt such costly practices. But they shouldn’t applaud themselves for feints toward eco-consciousness, as Vuitton did in a 2007 press release quoting its then-C.E.O.: “In recent years we have...increased our use of sea rather than air transport; minimized packing waste; and consistently reduced energy consumption in our workshops and warehouses.” Even Loro Piana’s vicuña wool has to travel from Peru to Mongolia for manufacturing.

But try to imagine a high-end fashion giant responding to our overtaxed environment by embracing traditional methods that are both more luxurious and less ephemeral. Now that would be a radical new design.