Green groups hope the film will improve awareness of how mankind is harming the planet.
Starring Jake Gyllenhaal and Emmy Rossum, The Day After Tomorrow sees the world plunged into a sudden ice age. The landmark Hollywood sign is destroyed by freak storms and New York’s skyscrapers are encased in ice.
But climate change expert and former US Government scientific adviser Tom Prugh said the scenario had been “Hollywoodised”.
He said: “There is evidence that abrupt climate change has happened a couple of times in the last 13,000 years, but it’s never happened in a few days, as it does in the movie.
“That’s completely impossible.”
He told National Geographic: “The scenario in the movie is fictional.”
Dr Prugh, senior editor at the Worldwatch Institute in Washington, DC, went on: “Like some other Hollywood movies that claim to be based on true stories, there’s a kernel of truth that is then pumped full of steroids and given cosmetic surgery.”
Despite his scepticism about the plot, he said he hoped people would “come away with the lesson that we need to be more careful with the climate that we’re fooling around with”.
The film was written and directed by Roland Emmerich, creator of Independence Day and Godzilla.
He said that The Day After Tomorrow would be his last disaster film.
“This one I think you can really come out and discuss it with friends and say, ‘Well, we have to do something or some day something like this could happen’,” he said at the premiere.