I believe that the overpopulation problem is one that humans can not handle. Every high-culture throughout history has gone down. This one will as well, not because I say so, but because of the historical consistency. The overpopulation and lack of temperance is part of the problem.
You'll see the beginning of the end when some start to talk about colonizing other planets or that they just can't wait for the end to come soon enough, that's their mindset that talks. And also have a look at the future based movies, same thing.
Perhaps earth was colonized, I'm just saying.
Just because something has turned out one way over and over doesn't mean it always has to do so. All we need to do is everything differently like stop believing there is an end to start by letting religions fade away like a bad dream and get on with Evolving towards Love away from Fear.