Hubbert Curve (Peak Oil)


Whenever we use a given resource like food, energy, water, or minerals, we wonder how long that resource will last.  For renewable resources like food or water, the resource will last indefinitely as long as the amount that we take does not exceed the amount that is regenerated.  For non-renewable resources like fossil fuels or minerals extracted from the earth, the longevity of the resource depends on rate of discovery and depletion - keeping in mind that resources become harder to find and remove as they become more scarce.

For the first half of the 20th Century, most people did not think about limitations of our fossil fuel resources.  That changed in the 1950s, when a geophysicist named Marion King Hubbard developed a curve that was applied to fossil fuel (particularly oil) supplies.  His curve has become known as the "Hubbert Curve" and has become a controversial topic for energy experts.

The Hubbert Curve is really a basic math function.  It
has a bell-shape that starts at zero, rises to a peak, and then drops off to zero again (see diagram with red line below).

The rising part of the curve has three parts (phases) that resemble an "S" shape: (1) an upwardly bending "lag" phase, (2) a rapidly rising "log" phase, and (3) a plateau that levels off.  Mathematicians call such an "S" shaped curve an exponential curve.

Exponential curves have widespread applicability.  For example, they can be used to depict the growth pattern for an individual organism or a population.  Medicinally, they can show how much oxygen is carried by the blood pigment hemoglobin as the amount of oxygen in your blood changes from low to high levels.

Unlike the exponential curve, the Hubbert curve has a parallel decreasing side that involves a rapid decline followed by tapering approach to zero (again, see diagram below).

In 1956, Hubbert used the curve to explain the future of petroleum supplies.  His curve included an increase in supply, a peak, and a decline.  The fundamental basis for his theory was that petroleum supplies are finite.  Therefore, the amount available in the ground will be ever shrinking - leading to a boom / bust cycle.  An important component of Hubbert's theory is that it can be applied at the local, regional, national, or global levels.

The curve, as Hubbert first described it, can be depicted by this diagram that has annual production on the Y-axis, and time on the X-axis:

When he originally presented his paper in 1956, Hubbert predicted that the production of petroleum would peak in the United States in the late 1960s, and worldwide about 2005.  He even predicted that annual production would top out at 12 gigabarrels.  Those predictions became known as the "Peak Oil" concept.

Since Hubbert's prediction has such profound ramifications to so many facets of our societal well-being, it has been subject to extensive review and revision.   Below are several curves that have been developed to test Hubbert's ideas.

This curve shows production in Norway.  Note the good fit of the data points with Hubbert.

This graph shows production of oil in the United States.  Note the peak was reached in approximately 1970, though the decline has taken longer than predicted by the Hubbert curve.

This curve shows daily production in non-OPEC nations.  Notice that each nation has a peak that was reached sometime between 1970 and 2004.


Some people agree with Hubbert's predictions, and use them to argue that we must limit our use of petroleum.  Others agree with the concept, but believe that supplies will last longer than Hubbert predicted.  Still others disagree with the concept altogether

A detailed discussion of Peak Oil is beyond the purpose of this course.  However some insights can be gained through the following readings:  .

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This page posted and maintained by Kenneth M. Klemow, Ph.D., Biology Department, Wilkes University, Wilkes-Barre, PA 18766. (570) 408-4758,