another good read from The Energy Bulletin

http://www.energybulletin.net/stories/2010-09-03/exponentially-purpose-century-and-half-ignored-warnings

an excerpt:

Hubbert continues:

These facts alone force one to ask how long such rates of growth can be kept up. How many periods of doubling can be sustained before the production rate would reach astronomical magnitudes? That the number must be small can be inferred from the fact that after n doubling periods the production rate will be increased by a factor of 2n. Thus in ten doubling periods the production rate would increase by a thousandfold; in twenty by a millionfold. For example, if at a certain time the production rate were 100 million barrels of oil per year – the U.S. production in 1903 – then in ten doubling periods this would have increased to 100 billion barrels per year. No finite resource can sustain for longer than a brief period such a rate of growth of production; therefore, although production rates tend initially to increase exponentially, physical limits prevent their continuing to do so.

This rapid rate of growth shown by the production curves makes them particularly deceptive with regard to the future length of time for which such production may be sustained. For example, coal has been mined continuously for about 800 years, and by the end of 1955 the cumulative production for all of this time was 95 billion metric tons.

It is somewhat surprising, however, to discover that the entire period of coal mining up until 1925 was required to produce the first half, while only the last 30 years has been required for the second half.

Similarly, petroleum has been produced in the United States since l859, and by the end of 1955 the cumulative production amounted to about 53 billion barrels. The first half of this required from 1859 to 1939, or 80 years, to be produced; whereas, the second half has been produced during the last 16 years Based on estimates of coal, natural gas and oil reserves, Hubbert suggested dates for “the ultimate peak of production” for each.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: