Another factor to consider is a concept called peak oil.  This is the point in time when the maximum rate of global petroleum is reached.  After the peak, the rate of production steadily decreases until the resource has been exhausted.  An energy crisis can occur if global consumption is not reduced before the peak.

Geophysicist M. King Hubbert predicted the decline of oil production in his book Hubbert’s Peak: The Impending World Oil Shortage.  While long-term solutions exist in the form of conservation and alternative energy sources, they probably will not be enacted in time to evade a short-term catastrophe.  We need to change our consumption habits now, not tomorrow.

photo credit: www.peakoilaware.org