Now, there are oil sands and shale oil. Currently they aren't really economically viable, but as the price of oil goes up they eventually will be. But, if we end up there- getting by on oil sands or shale oil- we clearly went down the wrong path because they cost more than green energy. The only reason we would be using them was because we failed to adopt to green energy by the time that we should have to be economically efficient and we still have a bunch of equipment that we can't switch over fast enough. Also, once we start getting into that stuff we're off the charts for global warming. Beyond even the worst case scenario projections.