The world is not going to end. Human existance will end one day, just like everything else dies off...then a new breed of human may or may not come...but the earth will remain, just with changes. The earth goes through a cleansing process every so often, and that's what it's doing right now. Think about it...cities with dirty air, end up with pretty clean air after days and days of rain, kind of like what happened down in Los Angeles less than a year ago. Sure, people fucked it up again, but it happens. Maybe natures plan is, to completely change the earth itself, and for that to happen, people needed to exist and fuck it up first. When mother nature wants us gone, she will get rid of us. She may call in a huge meteor, worldwide storms or even another ice age...but when she wants us gone, we will be...no divine plan about it, it's nature.
On a side note, it's kind of arrogant for people to believe that, when humans cease to exist, so will the earth. It's just like believing our planet is the only one that holds life in the entire universe. C'mon folks, the end of the world is not going to be the end of the world, it's just going to be human extinction...then a rebirth for whatever will run shit next. Sad thing is, we may cause our own demise before mother nature does her thing.