I'm stunned how many scientists, in different publications in different countries, have supported - without knowing - our film 
A master of Hollywood spectacle, Roland Emmerich delivers his most extravagant vision yet when the US gets torn apart by freak weather conditions in The Day After Tomorrow. German-born, Emmerich has been providing some of the biggest thrills in cinema over the past decade, from the time-travelling nonsense of Stargate to the destruction of the White House in Independence Day. He was also irresponsible for the monster-mash of Godzilla and the historical shenanigans of The Patriot. He will next make King Tut, the story of the young pharaoh who vies to reclaim his kingdom after the death of his father.
You raised the bar in special effects with Independence Day. How did you set about doing that for this movie?
It's a little bit different with this movie. Independence Day was about aliens. Although they were striking images, everybody knew that these spaceships didn't exist. In this movie, we want people to not realise that it's all visual effects. If they do that, they bring themselves out of the picture. So we have a very high level of quality we want to reach. We discussed with the visual effects companies beforehand that we wanted photo-real effects. Now, everybody says that, but we really meant it! They thought we were full of bull****! Then when the first visual effects came in, we simply didn't accept them. So they realised, all of a sudden, that we really meant it! In the end, we farmed out the work to several different companies, including ILM and Digital Domain. But we didn't plan for that - so it was a nightmare at first.
With the events of the film precipitated by global warming, could this really happen?
At the very beginning, when I started writing, I thought it was based on fact, but they are so compressed, it felt like science fiction. In the meantime, I have to admit, I'm stunned how many scientists, in different publications in different countries, have supported - without knowing - our film. The last article I saw, in Fortune Magazine, I read aloud in the editing room and I said "Oh, my God - it's much more real than I could have ever imagined!"
Would you hope the film will encourage people to think about the environment?
I think so. At the very beginning, we said: "That's the blueprint." It's young people who watch movies. Kids now have all this information, but they're not really political, and it's really hard to reach them with a documentary or a newspaper article. So a film is not a bad forum to present them with these issues, even if they go with their friends and just discuss for five minutes afterwards whether it will be possible. But I think this film defies age groups and gender-groups. It's very wide.
What made you choose Jake Gyllenhaal for the lead?
He was looking for the right big movie. He discovered us and we discovered him. I'd seen him in October Sky, Donnie Darko, The Good Girl. He makes things look real. You never get the feeling that he's acting.
