Coal and petroleum resources are limited. We should use them judiciously. Justify.
Coal and petroleum are fossil fuels. It takes the dead organisms millions of years to get converted into these fuels. On the other hand, the known reserves of these will last atmost a few hundred years. Moreover, burning of these fuels is a major cause of air pollution. Their use is also linked to global warming. It is therefore necessary that we use these fuels only when absolutely necessary. This will result in better environment, smaller risk of global warming and their availability for a longer period of time.