Bear with me ;)

A couple of weeks ago, Australian prime minister John Howard was ambushed on the campaign trail by protesters holding placards that read "Save Our Planet" and "Ratify Kyoto Now". But these weren't your usual weed-addled hippy agitators. These people were serious. You could tell by the way they were dressed as polar bears. These days, once a polar bear is involved in any sort of campaign, people sit up and listen. The enormous arctic creatures have become a global symbol of environmentalism, a humble martyr to global warming. Ever since we saw those bears stranded on a melted bit of ice in Al Gore's An Inconvenient Truth, the whole world has felt their pain. Every time we fill up the kettle, leave the TV on stand-by or forget to take our empty cans of Alphabetti Spaghetti down the recycling bank, we hear the agonised screams of a baby polar bear ringing in the back of our minds. These beautiful, glistening, cuddly giants of the north pole are dying because of our selfish, indulgent, plastic bag lifestyles. The upshot is that polar bears have been elevated to prestigious status in today's culture. As tragic as Princess Di, as brave as Nelson Mandela, as pretty as Alesha Dixon in Strictly Come Dancing and as rock hard as Jean-Claude Van Damme, the polar bear is all things to all men. No wonder it's cashing in.

For a supposedly endangered species, these animals are everywhere. Back in April, a polar bear cub called Knut appeared on the cover of Vanity Fair's green issue alongside Leonardo Di Caprio. This week sees the release of The Golden Compass, a Philip Pullman fantasy in which Ian McKellen voices Iorek Byrnison, a noble polar bear and protector of the film's little girl protagonist. He's one of the goodies. This follows Earth, documentary narrated by Patrick Stewart which followed the dramatic migratory journey of polar bears over a five year period. And coming next year from the makers of March Of The Penguins is Arctic Tale, in which we are invited to join storyteller Queen Latifah on Nanu the polar bear's journey from birth to adulthood in the frozen Arctic wilderness. Polar bears are big business and the undisputed mammal du jour. Kids love them, politicians love them and Hollywood loves them. Expect Nanu to turn up at next year's Oscars, stepping out of a giant stretch SUV with a couple of sexy Arctic foxes on her arms and a bottle of Cristal in one of her paws.

For Robert Buchanan, president of Polar Bears International, the appeal of the creatures is obvious. "They are majestic, powerful animals that are filled with personality," he says. "Play-fighting bears remind you of kids play-wrestling, and mothers with cubs show a tenderness that humans can relate to. Their intelligent versatility makes them endlessly fascinating to watch. Some of the interest may also come from the fact that a standing bear has a human shape. For that reason, the Inuit considered the polar bear to be wise, powerful, and "almost a man". Many tribes told legends of strange polar bear men that lived in igloos. These bears walked upright, just like men, and were able to talk. Natives believed they shed their skins in the privacy of their homes." Blimey. Certainly, the polar bear has an aesthetic appeal that's thoroughly modern. With its clean lines and brilliant white fur, it looks like it has been designed by Apple's Jonathan Ive. In reality, its skin is black and its fur is hollow and translucent, only giving the appearance of whiteness. Which, in a way, makes it cooler. This natural style, combined with the human similarities, have made polar bears a popular marketing device for decades. In the seventies, Cresta used an animated polar bear to advertise their soft drinks. Created by John Webster (the same adman who later invented The Honey Monster and George the Hofmeister Bear) it was based on Jack Nicholson's character in Easy Rider. Every time the bear took a sip of Cresta, he would launch into a joyful spasm (just as Nicholson had reacted to whiskey). The campaign ran for years and the bear's catch phrase "It's frothy man!" became a playground staple. Later, Fox's Glacier Mints used a slumbering polar bear as its brand mascot with similar success.

But it's global warming that has reinvented the polar bear as an era-defining icon. Earlier this year, viewers of BBC One's Planet Earth saw this problem up close. A desperate bear, deprived of its natural seal hunting environment, suffered the indignity of being beaten up by a bunch of walruses on camera. That, and widely syndicated pictures of bears drowning in melted ice, has had us clambering to embrace the seemingly endangered species. Edinburgh Zoo is home to Mercedes, the UK's only polar bear. "She's one of the top attractions at the zoo at the moment," says senior keeper Sharon Hatton. "People think it might be a chance to catch a glimpse before the species disappears. Films make a big difference. After March Of The Penguins and Happy Feet, everyone was rushing to the penguin enclosure. Now, it's beginning to happen with the polar bear." Mercedes' stock is rising. This year, her number of adopters has risen to 160, challenging the king penguin's status as the zoo's most popular attraction.

The polar bear is hot - both literally and metaphorically. But how much of this increased kudos is credible? A debate still rages about its endangered status. Some reports have suggested that 25,000 bears lurk in the north pole today - compared to just 5,000 in 1950. One thing is certain: these animals are far less cuddly than cinematic depictions suggest. In fact, they're the bear species most likely to hunt humans. "Most wild animals will only attack you if you directly threaten them or their children," says former SAS commander Chris Ryan, who has encountered polar bears in the wild. "But polar bears will track humans down and take a week to do it. They have an incredible sense of smell and will detect humans from miles away. In the north pole at night, temperatures become too cold for humans to move. But that's when a polar bear will strike."

It's enough to put you off your Fox's Glacier Mint. Whether their population is on the increase or not, the disappearance of their natural habitat is driving polar bears further into human communities, such as Churchill in northern Canada, where they are often found scavenging in rubbish bins. The species might be riding on the crest of a publicity wave at the moment, but fame is a fickle mistress. It may only take a few backyard attacks on innocent Canadians for them to be reduced to the lowly status of a rubbish urban pigeon. And this time next year - who knows? - we could all be going on about the Arctic leopard instead.

Animal planet: Each decade has its favourite animal...

1970s: The Lion

With its orangey brownish hue and main of extravagantly coiffured hair, the lion defined the seventies aesthetic. Prancing about the jungle like the original medallion man, the big cat was barely distinguishable from Barry Gibb. The now hard to find Lion Bar was a 1970s playground favourite.

1980s: The Tiger

Michael Jackson cuddled one on the decade's biggest selling album cover. Del Boy favoured the animal's fur print as an interior design feature. And Rocky pounded the streets of Philadelphia to the strains of Survivor's Eye Of The Tiger, the lyrics being a fierce endorsement of Thatcherite individualism.

1990s: The Monkey

While the monkey is a perennial favourite that transcends generations, it made the Britpop era its own. Rock luminaries such as Liam Gallagher and Ian Brown based their walks on the gangly primates, designer Paul Frank devised his monkey-based fashion range and took the high street by storm.

Early 2000s: The Penguin

In the grips of 21st century angst, a generation embraces the humble penguin. With thousands of miles to walk in sub zero temperatures, penguins are far too busy to worry about stuff like Iranian nuclear proliferation. Movies Happy Feet and March Of The Penguins cement the bird's iconic status. And everyone starts wearing jumpers with them little Penguin crests on them.