Economists do not worry that the supply of petroleum will run out this century. They have a naive belief that supply restrictions will cause a price rise and that will create an alternative to oil. Economist's do not tell you that in the 1930's an economist, Harold Hotelling, investigated the most economically efficient way of coping with a depleting resource and produced a rule for using up a resource in the most economically efficient way.

He proved that for maximum economic efficiency, the price of the resource should increase steadily at the "social discount" rate. In other words, the price of petrol, fuel oil, and diesel should rise, through taxes if necessary, at the rate of return on capital investments. The rising price should contain consumption so that consumption drops to zero as the resource runs out. A steady rise in price of petrol, fuel oil, and diesel could be engineered with a carbon tax. This would allow the development of alternatives in time to become economically possible to introduce without excessive risk.

Politicians, particularly in the US, put a lot of effort into keeping the price of motor fuel low. This enables the demand on motor fuel to be unconstrained and at the same time making it uneconomic to prepare an alternative. When the supply becomes restricted, as it must do eventually, the prices will rise dramatically while our society will have become hopelessly trapped into extreme dependance on current liquid fuels. Then there will be no time to build the infrastructure required for any alternative should there be one suitable. Keeping prices low is a dangerous economic trap.

However, there remains the problem of a substitute for energy. Economists (but not scientists) tell us that technology will come up with an alternative supply of energy. People talk about a coming hydrogen economy and note that there are endless supplies of hydrogen in water. They do not realise that water is hydrogen that has already been burnt so water is not a source of energy. Hydrogen is currently manufactured from coal or natural gas in processes that are quite energy inefficient. Hydrogen is a gas that is difficult to manage and distribute. A storage and distribution system for hydrogen has yet to be designed let alone built. It will not be feasible to ship hydrogen in tankers. Normal pipeline materials will not work for hydrogen. Hydrogen will not be suitable to fuel either ships or aircraft. Economists will not tell you that they know nothing about how a hydrogen economy would work.

Economists do not tell you, but our industrial/technical society will be strictly limited by energy supply eventually. Our current consumptive society will be forced to an end