World oil production will start to fall sometime during this decade, never to rise again. In 1956, M. King Hubbert predicted that U.S. oil production would peak in the early 1970's. Although Hubbert was widely criticized by some oil experts and economists, in 1971 Hubbert's prediction came true. The 100 year period when most of the world's oil is being discovered became known as "Hubbert's Peak". The peak stands in contrast to the hundreds of millions of years the oil deposits took to form. Hubbert's methods predict a peak in world oil production less than five years away
http://www.princeton.edu/hubbert/the-peak.html