Coal and petroleum are called fossil fuels. Coal and petroleum are the natural resources which are important ‘sources’ of energy for us. Coal is used as a fuel as such in homes and in industry, or it is used to generate electricity at Thermal Power Plants. Petroleum products such as petrol and diesel are used as fuels in transport to run scooters, motorcycles, cars, buses, trucks, trains, ships and aeroplanes.
Kerosene and LPG (Liquefied Petroleum Gas) obtained from petroleum are used as domestic fuels for cooking food, etc. Since the industrial revolution, we have been using increasing amounts of energy to meet our basic needs (like cooking food) and for the manufacture of goods upon which our life depends. All these energy needs have so far been met mostly by coal and petroleum reserves of the earth.
Coal and petroleum were formed from the degradation of biomass of plants and animals respectively, buried deep under the earth millions of years ago. We obtain coal from the ‘coal mines’ dug into the earth and petroleum is obtained by digging ‘oil wells’ deep in the earth.
The crude petroleum oil obtained from oil wells is then separated into fuels such as LPG, petrol, diesel and kerosene. We have been using coal and petroleum resources at such a rapid rate in the past that they will get exhausted in the near future.
It has been estimated that at the present rate of consumption, the known petroleum reserves of the earth will last us for just about 40 years more and the coal will last for about another 200 years only. Once exhausted, coal and petroleum will not be available to us in near future (because they are formed extremely slowly over a very, very long time). It is, therefore, necessary to conserve (or save) coal and petroleum resources of the earth by reducing their consumption so that they may last for as long as possible.