I hated that book. Never saw the movie.
I was probably 12 when I read it, and I knew it was scientific bullshit even then, not to mention that I could think of dozens of ways for humanity to survive that would occur even to a 12-year-old. "And then everybody gives up and dies" is a hell of a way to end any book, and this isn't the only example in fiction.
I preferred "Alas Babylon."