>I'm not sure that "alienation from nature" is a meaningful concept.
It is if you're trying to communicate something in a ten minute segment of a movie. Zizek is very good at doing that.
Elsewhere he says, on page 8 of an 11 page article:
And does ultimately the same not go for nature itself? Here, “negation of negation” is the shift from the idea that we are violating some natural balanced order to the idea that imposing on the Real such a notion of balanced order is in itself the greatest violation
which is why the premise, the first axiom even, of every radical ecology is “there is no Nature.”
http://zizekstudies.org/index.php/ijzs/article/view/41/64