I don't see the difference between this and The Day After Tomorrow to be honest.
Size matters: a winter popcorn movie and guilty pleasure, this mass entertainment of mass destruction is not one coherent story but a calculated, cliche-ridden, often humorous pastiche of all the disaster movies made in Hollywood.
John Cusack has barely any role in it. It could've been any random bloke off the street instead of him and it'd still be the same as plot and characters have no meaning in this movie.