Reading 7.indd

Our industrialized society feeds greedily and insatiably on energy made available by burning fossil fuels—coal, petroleum, and natural gas. This stored energy was captured from the sun eons ago by plants whose remains became buried deep in the earth’s crust. These fossil fuels are of course limited, and the effi ciency with which we use them, which depends on our level of technology, will determine our standard of living for some time to come. Although we obtain some energy from water power and increasing amounts from nuclear reactors, the amounts obtained from these sources are still insignifi cant on a world basis. The world energy use is equivalent to the consumption of 4.8 billion metric tons of coal annually. Dividing this fi gure by the earth’s estimated population of 4.6 billion gives an energy equivalent of 1.04 metric tons of coal per capita per year. To compare the energy costs of today’s technology with those required for primitive cultures is revealing (Fig. 1). In primitive agricultural societies, of which there are many in the world even