Even coal will last only 170 years. And it is likely that as Third World countries begin to develop their own industries, they will demand their fair share of energy too. Very soon then, there will not be enough fossil fuels to meet demand. Moreover, the mounting use of energy is already harming the environment. Burning massive amounts of fossil fuels, for instance, pollutes the atmosphere badly, contributing to global warming, while large hydro-electric plants can not only drown farmland but devastate natural habitats by changing the flow of rivers.
Many people feel that the use of too much energy is the major problem facing the world.
We get our electricity from ten major sources. In the 19th century, coal was the most important of all fuels, powering the steam engines of the Industrial Revolution, and keeping people's homes warm. Today it is still used in vast quantities, especially in countries like China where there are huge reserves. About half the coal mined each year is burned in power stations to generate electricity, a quarter is used for making steel and the rest is burned in home fires. When the plants died, they fell into the swamps and became covered with mud.