It includes a part where some choppers flying in the UK suddenly get caught up in an extreme drop in temperatures, get iced, and drop out of the sky.
The film was a total work of fiction which drew heavily upon prevailing scientific opinion, but was criticized for over-the-top predictions. The main criticisms from scientists was the time-scale. They said all these things were not possible in the short span of hours the movie shows, and that the extent wouldn't be so exaggerated.
Nature may be a little more imaginative.