I read that book also and thought it was pretty thought provoking.
The setting is post apocalypse but they don't really ever say what exactly happened. All the trees and plants are dead and there is ash covering
That could have been from a massive fire (think after a big meteor strike) or after a nuclear war. The event took place in the past, from the
perspective of the characters in the book.
The move is supposed to be coming out this year. The father will be played by Viggo Mortensen.
I'm looking forward to it.