Frankly humans tend to not see what's right in front of them. For example, experts were saying that the real estate bubble was going to pop and plunge America into a huge recession within a couple years. Nobody could see past the small profit they would make within the next few weeks, and we all ended up paying for it.
Same theory different scenario. The real effects of not recycling and saving energy haven't shown themselves on a huge scale yet. People aren't going to give up their laziness for the small things (small on a global scale at least).
My opinion on it is simple, if we destroy the world like we're currently doing we won't live to see the consequences. We'll all be dead. The world will flush all traces of our existence from its soil. And maybe in a few million years another species will evolve, take our place, and make the same mistakes.