The sooner oil gets really expensive, the better for us all. The masses will get angry and their governments will finally be forced to invest serious money into alternatives instead of the pathetic sums that they do now. Had America invested a trillion dollars on research instead of killing people on the other side of the world we would be very close to, if not already at an alternative. I believe it will be hydrogen from the worlds oceans. Practically overnight the oil, coal and nuclear industries will become obsolete. Supplemented with solar, wind, tidal etc. Hydrogen from oceans could power many desalination plants for irrigation, human consumption, and provide the clean water needed to extract the hydrogen fuel. Even relatively amatuer efforts have produced impressive results. Imagine if the world really applied itself to this goal. There are many, many examples. Here are some:
