In a spin: Events in The Day After Tomorrow, like the group of tornadoes that raze Los Angeles, are near-impossible, say UCT climatologists.

For a movie that should be taken with as much salt as you can stand on your popcorn, The Day After Tomorrow has snowballed into one hot topic.

Not bad for a film that hails from the same Hollywood stable that thought up Independence Day and Godzilla, films that paid overblown homage to the maxim that bigger - much, much bigger - is better (or not, if you agreed with the critics). In The Day After Tomorrow, the filmmakers stuck to their big guns.

The $125-million behemoth recounts how, in a matter of days or weeks (time-keeping is fuzzy), global warming plunges the northern hemisphere into a new ice age. According to the straight-faced script, the melting of the polar ice caps floods the Atlantic Ocean with fresh water, shutting down the Atlantic thermohaline circulation (the Atlantic thermohaline circulation, which includes the Gulf Stream, acts like an oceanic conveyer belt that carries heat from the tropics to the North Atlantic region, and is dependant on the interplay between temperature and salt content). This shutdown triggers a blitz of natural disasters - a 13-degree drop in ocean temperature, snow-storms in India, jumbo hailstones that pelt down on the denizens of Tokyo, a cluster of tornadoes that rip Los Angeles apart, and three ginormous hurricanes that drag freezing air from the upper atmosphere and drop it on hapless cities down below. Then, of course, there's the tsunami and ice age that sweep Manhattan - just recovering from the damage inflicted by Godzilla - in quick succession.

The Day After Tomorrow boasts all the essential plot developments and characters peculiar to disaster-cum-apocalypse flicks. The worst-case scenario, the city/planet under siege, the corny dialogue, the storylines of families torn apart and courting couples drawn closer, and the ridiculed scientist (sometimes fireman) who knows what's happening but can't get anyone to listen to him - all these have become the stock-in-trade of the genre since the days of The Towering Inferno and Earthquake of the 1970s. Only these days, of course, there's CGI (computer-generated imagery), and that gets better and pricier by the blockbuster.

To their credit, however, the writers of The Day After Tomorrow occasionally flaunt a wicked sense of political humour. So, for example, audiences can chuckle along when the filmmakers have the Mexican president close the Mexico-US border to stem the tide of American refugees overrunning his balmier countryside.

As apocalypse flick, The Day After Tomorrow is perfectly passable bunkum.

But back in the US the film and its creators have developed political pretensions, sparking debate since it's been adopted as banner-film by statesmen and environmentalists, including former vice-president Al Gore and high-profile activist group MoveOn.org. They hope that the movie - its flawed science and hyperbole notwithstanding - will stoke discussion and rekindle interest in issues around global warming.

Others, like government scientists and scholars, fear that the movie's science fictions may blind audiences to the real science and the real concerns.

UCT's Associate Professor Bruce Hewitson, head of the Climate Systems Analysis Group (CSAG), is inclined to sympathise with this view. "I deal a lot with politicians and people who would do anything to avoid doing something about these issues," he said after attending a preview screening of the film (during which he had a couple of good laughs). "My concern is that they could easily point at a film like this and say: 'Look, it's all nonsense'."

And there are quite a few severe distortions serious science in the film, he points out. The abrupt onset of the ice age and the timeline of the polar melting is near impossible, likewise much of the physics is impossible, and there's little chance that global warming is going to lead to global cooling, he reports.

Emma Archer, a research associate with the CSAG, agrees with Hewitson as far as the science is concerned, but holds a different view as to The Day After Tomorrow's social and political impact. She points out that audiences, their interest piqued by the film - and over-the-top it may be - appear to have already made their way to a couple of websites that cover the science more accurately. "It's good to get people talking about the issues," she says.

Other CSAG members to attend the screening take a lighter view of the film - once they'd stopped laughing at the science. Amid the film's fallacies and gaffes, Dr Remi Tailleux and doctoral student Suzanne Carter even spotted a couple of true-to-life moments - scientists drilling at the poles (although there's usually more than three of them, says Tailleux), indolent government officials, the researchers' empty coffee pots. As goofball as the science may be, Carter admits to taking a shine to The Day After Tomorrow. "It's a good disaster movie," she said. "And the CGI is fantastic."

Hewitson, however, figures he could have put the film's overblown budget to much better use - although maybe not nearly so cinematically - had the Tinsel Town cheque landed in his fund instead. So, for instance, he and his group could have produced a must-have impact analysis (and climate modelling) for southern Africa that could match that of the developed world, he says. "We could do it with half of that," he snorts.

Monday Paper would like to extend its thanks to Emma Archer, Suzanne Carter, Assoc Prof Bruce Hewitson, Chris Jack, Anna Steynor and Dr Remi Tailleux for joining us for the press screening of The Day After Tomorrow, and for chatting to us.