Do you have to be a nut to think the end of the world is near?

Do you have to be a nut to think the end of the world is near? I'm not walking around with a sign hanging around my neck saying Repent, The End is Near! However, I do see that humans are depleting the natural resources at an alarming rate. Fortunately, it isn't quite as quickly as I once thought (that I would never have kids because all of the crude oil reserves would be used up in my lifetime), but the rate is nevertheless alarming.

The question is, are we in a cycle or a trend? Do all of the warning signs mean there will be some "reset" in the future and then humans can start over and hopefully do a better job? Can anything repair the hole in the ozone layer or refreeze the polar ice caps or replant the Amazon rain forest or rehydrate the advancing Gobi Desert? If the planet is on a cycle, then human extinction is relatively near. If it is a trend then...well, the same conclusion, the end is near...a few centuries? a few millenia? What will life be like in the year 5000 and will humans be around to experience it? You tell me.