Petroleum-future. Petroleum has played a vital role in the economic, social, and political history of the world. ... As the 70% of all crude oil produced is used by the transportation industry, great effort has been put to produce an electric vehicle capable of performance similar to that of petroleum powered vehicles. Petroleum has played a vital role in the economic, social, and political history of the world. Petroleum is being used as a source of energy production since nineteenth century. The concept of peak oil has been proposed by M. King Hubbert's theory. It is explained that peak oil does not mean that petroleum reserves have run out, but that the maximum rate of petroleum extraction has been reached and that subsequent methods of extraction cannot increase the rate further. And hence the total rate of petroleum output will decrease. This phenomenon poses a threat to Petroleum future.