I also ask myself this question everyday and I had to do some research. I have come to realise that oil makes the world to be truly globalized..or how can we explain the fact that a child travels to another city for his grandfather "s burial the same day he learnt he passed. Their are about 1.2 billion passenger cars alone and 98% of them rely on oil.That figure is expected to reach 2billion by the year 2035 and 3 billion by the year 2050.This year,world vehicle sale will reach 89 million,37% increase since 2005. The world consumes about 24 million b/d of gasoline,27 million b/d of fossil fuel every day.That's a lot and the figure is expected to rise.. As at now,the USA has 82 cars per 100 people, China has 7, and India has 4 cars per 100 people.This figures will rise in coming Years. Also,the developed nations use 50% of the world oil but are just 17% of the population.From 2010 to 2030,the poor nations are projected to add 800 million newly registered vehicles and most of this vehicles will depend on oil. Oil will continue to run the world.Apart from running cars, we use oil to run some machines like the generator and so on.