End of Oil
The demand for oil increases each year, but the supply is not inexhaustible. Experts predict that within 30 years our oil energy sources will be depleted. In his book, The End of Oil: On the Edge of a Perilous New World, Roberts looks at the implications for the world in terms of the economy, politics and the environment, and what alternatives exist for oil. Roberts writes about the energy industry for Harper's magazine and for other national publications.
Paul Roberts is an excellent speaker - I highly recommend listening online, or if you can meet him on his book tour.