Just not enough oil to go around

Another year, another record oil price. The immediate reasons why the price of a barrel of oil jumped $4 to $100 yesterday were a cold snap in North America and unrest in two important producing nations: Nigeria and Algeria. Beneath the surface, however, the key fact about oil has not changed, and it is an uncomfortable fact: there is not enough being produced. Or, more precisely, there is not enough spare capacity in places such as Saudi Arabia to prevent regular price spikes. It is why $100 oil no longer looks like an aberration, but the norm for a while yet.
The International Energy Agency warned last year of a “crunch” in supplies in five years’ time. Unless we have serious global recession to stifle demand, that forecast may turn out to be conservative in its timing.

Guardian