"The greatest shortcoming of the human race is its inability to understand the exponential function". You can watch this as a 57 minute lecture or watch in 8 separated parts with updated slides. I recommend the second option. (http://www.albartlett.org/presentations/arithmetic_population_energy_video1.html)
On you tube is is dubbed "the most important video you will ever watch" and I don't think that is much of an exaggeration.
For further information on Al Bartlett go to: http://www.albartlett.org/index.html