PredictionThe brilliant Nils Bohr said "prediction is very difficult, especially if it's about the future." Oil usage may well fall but the reduction may well take a fairly slow path for several reasons. Many vehicles and furnaces have long life spans, ie commercial planes, farm tractors, smelters, etc, etc. Many countries are very hard to herd into a virtuous circle, see U.N., cats. In addition, while the rate of population increase in developed countries is very low, the rate in the developing world is much higher where future demand for energy is likely to be very high. Market pricing will determine the rate at which oil usage declines worldwide.