What happens after the oil is gone?

Though technology seems to be getting close that might let us use sunlight to split the hydrogen out of water. If that process can be made efficient enough, with catalysts that are available enough (platinum and ruthenium may not be a good fit there), maybe we can separate solar-derived fuel both from fossils and from the hours that the sun is shining. Not that it will be easy....

Pressurized hydrogen is also dangerous, even more so than, say, pressurized natural gas, if only because it burns with no smoke and no real color to the flame. Lots of research is going into things like metal hydrides for storage, and I think some real progress is being made. I only follow this stuff in Nature, though, so I may be seeing the academic side of the research that might never make it to an automobile.I don't much care for the idea of 17-year-olds fuelling a car with H2 at 1900 psi while they're texting their friends, though. But hell, they do it with gasoline.