oil is the lifeblood of the World's economy. It was a critical element in two World Wars and in the Cold War, and, as recent events in the Middle East confirm, people are willing to fight for it. The cheap energy it provides, especially for transport and agriculture, was one of the main factors that made possible the economic prosperity and growth that the World has enjoyed for the past fifty years and more. People rely on it everywhere, and in many forms, and they have become so accustomed to its ready availability that they take it for granted. To conceive of a world without traffic jams...