As long as we depend on oil to fuel the engines of the world , it will continue to play a major role in our lives, But research is ongoing in many countires to find ways to harness new sources of energy.
Perhaps on day our cars will have electricity powered engines and run on batteries that must be recharged every few hubdred kilometers . Or, perhaps the batteries will draw on the sun's energy and recharge even as we drive. Who knows what the future holds ?
One thing that is certain, however, is that the air pollution resulting from the combustion of fossil fuels such as petroleum and coal is of increasing concern to the inhabitants of planet Earth.
Thus. the search for a non-polluting replacement energy source is one of the most important challenges faced by humankind.