All this talk about alternate sources....most of which require oil to manufacture & transport.
Well, how about manpower ? For most of the history of humanity, we relied on manpower to get everything done. Sure, life wasn't all that great. It was hard work and the casualties were high. But this is exactly where we are going once again. Think of how the natives used to live in North America 500 years ago. Life will be similar to that 500 years from now. Talk of the end of oil causing the extinction of humanity is ridiculous. Millions of humans around the world today survive without using oil in any form. Sure, their life isn't easy. But life was not meant to be easy. We are just another animal meant to live off the earth's resources and work for everything we need. The casualities will be high at first. Then the natural world will start to regenerate. Animals will become abundant once again, water will become clean. What humans truly need to survive - just food, water & shelter - will be available. Human numbers will stay in check, controlled by disease and the things that controlled human population for millions of years. The population explosion witnessed over the last 150 years will never occur again, since this explosion has been enabled by - you guessed it - oil.
End of oil won't be pretty. But humans will survive (at least until earth gets hit by an asteroid, burned up by the sun, or sucked into a black hole)