Which 1956 theory predicted that United States oil production would reach a peak around 1970?

Hubbert peak theory predicted that United States oil production would reach a peak around 1970.

Geophysicist M. King Hubbert presented the theory in 1956. He modeled production from a finite petroleum resource as a bell-shaped curve, rising during discovery and development, peaking when roughly half the recoverable resource had been produced, and then declining.

Hubbert estimated that U.S. oil output would peak between 1965 and 1970. Lower-48 crude production did peak around 1970, a result that made the theory widely known, although later production from Alaska and the Gulf of Mexico changed national totals.

The theory concerns production rates, not the date when oil physically runs out. Technology, prices, new discoveries, improved recovery and changing resource estimates can alter the shape and timing of a production peak.