Energy consumption has increased remarkably over the past half century mainly due to increasing population and economic development. The influences of these two factors are considered. In most developed countries, such as Japan, France, Germany and Korea, the growth rate of energy consumption is due to economic development. The effects of population in Germany and Japan will substantially decline. In the USA, it is due to both factors as well as in the developing countries, such as China, India, Indonesia and Latin America. Economic success is more effective than increasing Population in China, India and Indonesia, while both factors are roughly equal in Latin America. In Africa, though the growth rate depends on the effect of increasing population, its contribution to world energy consumption is small. On a worldwide scale, the growth rate of energy consumption will be affected by improving standards of living.