Peak oil, an event based on
M. King Hubbert's
theory, is the point in time when the maximum rate of
extraction of petroleum is reached, after which it is expected to enter terminal decline. Peak oil theory is based on the observed rise, peak, fall, and depletion of
aggregate production rate in
oil fields over time. It is often confused with
oil depletion; however, peak oil is the point of maximum production, while depletion refers to a period of falling reserves and supply.