Save the planet? That's so cool...

Gas-guzzling stretch limos are out, recycled lavatory paper is in, as the A-list embraces environmental righteousness. But is it really about reforestation, or just reputation? Oliver Bennett sorts the ego-tourists from the truly eco-friendly

Hollywood's elite is in the grip of a passion for the environment that has set a mood of conspicuous non-consumption: the expression of ecological virtue is the biggest image-plus in town. These days in Los Angeles, no-one would look into a stretch limo expecting to see a genuine celebrity. Instead, the truly famous are to be found in that unassuming Toyota Prius hybrid over the road, with copies of Grist, the environmentalist magazine, and William McDonough and Michael Braungart's Cradle to Cradle eco-bible, on the passenger seat.

Hollywood's elite is in the grip of a passion for the environment that has set a mood of conspicuous non-consumption: the expression of ecological virtue is the biggest image-plus in town. These days in Los Angeles, no-one would look into a stretch limo expecting to see a genuine celebrity. Instead, the truly famous are to be found in that unassuming Toyota Prius hybrid over the road, with copies of Grist, the environmentalist magazine, and William McDonough and Michael Braungart's Cradle to Cradle eco-bible, on the passenger seat.

Take the most-talked about TV show in America right now, MTV's Trippin. Here, a roster of stars including the actresses Cameron Diaz and Drew Barrymore crash through eco-tourist zones such as the Chilean rainforest, un-made-up, uninhibited and (some might say) unhinged. They're, like, into radical self-reliance and recycled toilet paper. "I took a poo in the woods hunched over like an animal," gushes Barrymore in the show. "Awesome!"

Less eco-tourism than ego-tourism? Possibly. Whatever, Trippin is of the moment, as it tells of Hollywood's infatuation with environmental righteousness. The A-list understands that the path to approval is no longer found through dreary old self-obsessed drink-and-drug confessions, but by environmental endeavour. These days, you've got to wear your credentials on your unbleached hemp sleeve.

The stars who make donations to ecological charities and concerns are legion. Cameron Diaz, Leonardo DiCaprio and Brad Pitt have all given to the entrepreneur Dan Morrell's initiative Future Forests, to offset the emissions they create in their daily life and to weigh up their "carbon neutrality". FF has also benefited from the patronage of rock bands such as the Foo Fighters, Coldplay and Massive Attack. Sharon Lawrence (Maisy Gibbons in Desperate Housewives) sits on the board of Eco, which campaigns for coral reefs. The actor Edward Norton is involved with various environmental agencies, and has narrated ecological documentaries like PBS's Strange Days on Planet Earth, which was full of portents of global disaster.

As bien-pensant types, Hollywood celebs are good eco-consumers. Because of the wonders of paparazzi photography, we know that the actress Liv Tyler buys Seventh Generation chlorine-free nappies. More visible yet are those stars queuing up to buy hybrid electricity-and-petrol cars, particularly the Toyota Prius: Gwyneth Paltrow, Salma Hayek, Charlize Theron, Scarlett Johansson and Orlando Bloom are among those who have managed to beat the waiting list for this motor, currently the most un-showy status symbol in the US.

It all fits into the new moral credo of voluntary simplicity, wherein flash is over and an almost ostentatious understatement has taken its place. Even Arnold Schwarzenegger has demonstrated a green sensibility - albeit in the most Arnie way possible - by stating that he wished to convert his Hummer to run on hydrogen.

Environmentalism is hardly a contentious issue to expound, and one might argue that these celebs are playing to a safe consensus. "I see it as part of the popular sentiment that surrounds environmentalism," says Benny Peiser, a social anthopologist at Liverpool John Moores University who has a particular interest in environmental media. "The celebrities are voicing something that's part of our accepted culture, however counter-cultural it may seem, and if you want to stay popular, you work within the mainstream. But I don't think it's harmful, and it's probably deeply felt. I'd be much more worried if they were endorsing parties like the BNP, say."

If it's good for celebrities, then it's also good for environmental charities, which can enjoy a wider range of celebrity endorsements. "We have no problem with Cameron Diaz or whoever being interested in environmentalism, as it might attract members of the public or new donor groups who haven't paid attention to such issues before," says a spokeswoman for Friends of the Earth, which is about to roll out Thom Yorke of Radiohead in a big climate change campaign.

"Of course, there are considerations about reputation, and if the celebrity doesn't understand the case being made, that could be very damaging. They've got to be genuine." Otherwise, she says, it'd be like kids wearing an anti-bullying wrist-band and belting their classmates.

Ruth Cherrington, a cultural studies lecturer at the University of Warwick, is more cynical. "I think there has to be an element of marketing and publicity involved," she says. "If a reader knows about a celebrity's environmental persuasion, then a decision has probably been taken to publicise it."

There's nothing wrong with that, but, just like corporations, celebrities might well be keen to indulge in a bit of "greenwashing", by which their eco-virtue becomes a marketable force. Yet this could still work beneficially in both directions. "Taking these issues into new constituencies might be good for the environmental agenda," continues Cherrington. "Environmentalism might still need to take its message beyond the beards and sandals image."

But might this just be the latest instalment in the celebrity search for self-fulfilment? In 1972, the Italian sociologist Francisco Alberoni coined the term "powerless elite" to describe the condition of celebrity, suggesting that entertainers may have wealth and status but feel trivial as they have no real purchase on society. These days, celebs have to be seen as doing good or "giving back", and Barrymore's poo in the woods may be her way of doing just that.

Edward Norton

* These days Norton - the star of American History X and Fight Club - is almost as famous for his eco-activism as for his acting. Recent projects include transforming an elevated New York railway into a green trail, and helping to create the BP Solar Neighbors programme, which aims to get cheap solar power for low-income families.

Brad Pitt

* As an environmentally-unfriendly mega-celeb, Brad Pitt had to make conspicuous amends. He gave $10,000 to have a forest planted in his name in Bhutan, and he was given first bash at the new Lexus RX 400h luxury SUV hybrid. Ah yes, cars: "We have the technology for electric cars, and we have other power sources," says Pitt.

Leonardo DiCaprio

* Leo used to rampage with a group of NY brats known, unpleasantly, as the "pussy posse". Now he's the perfect enviro-gent. He drives a low-carbon emitting electric car, and his foundation's "eco-site" features sections on global warming and sustainability. Leo is also working to get President Bush to sign a treaty proclaiming clean water a human right.

Tamzin Outhwaite

* Tamzin was Wild With Dolphins on BBC television and went all gloopy. "From an early age, I knew I wanted to act," said the ex-EastEnders actress. "The second on my list of ambitions was to come face-to-face with a dolphin." Cockle-warming stuff: and, as with Diaz and Barrymore, it gave viewers a chance to ogle Outhwaite's bikini.

Goran Visnjic

* The ER mock-doc Visnjic has cast his lot in with the International Fund for Animal Welfare after watching seal-hunting videos. He now says that he wants to promote seal-watching rather than seal-hunting, and to encourage seal-reliant communities to make money from tourists instead. This is fine, but some may think seals are just a little bit routine.

Woody Harrelson

* The actor has designed an "eco-suite" at the Hotel Triton in San Francisco, and for each guest who stays, a charity gets 10 per cent of the rate. Harrelson's eco-activism is deep and developed when he was in Cheers (his co-star Ted Danson was involved in the American Oceans Campaign). He now fronts Oasis Preserve International, a rainforest action group.

Daryl Hannah

* Still most famous for playing a sexy mermaid in Splash, Daryl Hannah lives in an old Wild West stagecoach station in the Rocky Mountains. It is solar-powered, backed up with bio-diesel and is fashionably "off-grid", as electricity refuseniks are known. Hannah even chooses to recline on moss that she has cultivated, rather than use a sofa.

Sting

* The square-jawed grandfather of the green celebs, Gordon Sumner started thinking global in the 1980s when he founded the Rainforest Foundation, doing his bit for trees and indigenous tribes. He scolded the Brazilian government and was roundly ridiculed by the British media. But he can hardly be said to be a faddist.

Chris Martin

* Chris Martin takes a lot of flak for being a "knit your own yoghurt" type, but there's no doubting his sincerity. He's into fair trade and he has also planted lots of trees, an act that is de rigueur for eco-celebs. He, wife Gwyneth, and daughter Apple are surely one of the more sensitive celebrity families: unfortunate then, that Chris's dad, Anthony, applied to build 160 houses on a protected environmental site in Exeter.

Sienna Miller

* Miller, the squeeze of Jude Law, examplar of boho-chic and all-round MAW (Model Actress Whatever) is a queen to British teens. So it's salutary that she helps promote sustainable clobber by speaking out for the "fair-trade ecology fashion" company, People Tree. "There's no reason why organic and fair-trade clothing can't be sexy," she pouted recently.