Most people do not understand exponential growth, yet the concept is of fundamental importance. Lecture by Dr. Albert A. Bartlett, professor emeritus of Physics at the University of Colorado-Boulder.
See also: http://en.wikipedia.org/wiki/Exponential_function
Part 1: http://edutube.org/en/video/arithmetic-population-and-energy-part-1-8
Part 2: current video
Part 3: http://edutube.org/en/video/arithmetic-population-and-energy-part-3-8
Part 4: http://edutube.org/en/video/arithmetic-population-and-energy-part-4-8
Part 5: http://edutube.org/en/video/arithmetic-population-and-energy-part-5-8
Part 6: http://edutube.org/en/video/arithmetic-population-and-energy-part-6-8
Part 7: http://edutube.org/en/video/arithmetic-population-and-energy-part-7-8
Part 8: http://edutube.org/en/video/arithmetic-population-and-energy-part-8-8