|Rampage, Janet.Energy: A Guidebook Second Edition. New York: Oxford University Press, 1997: 13.||"… arithmetic shows that world annual consumption of primary energy is about 380 EJ …."||12.1 TW|
|Renewable Energy: Power for a sustainable Future. Ed. Godfrey Boyle. New York: Oxford University Press, 1998: 10.||"Estimated annual world primary energy consumption,1992, by source 398 EJ (9476 mtoe)."||12.6 TW|
|"Energy Supply." World Book Encyclopedia. Volume 6. Chicago: World Book-Childcraft International, Inc, 1979: 226a-h.||"In 1974 the entire world used about 2.3 ton of coal of energy per person …."||0.055 TW|
|Table E1 World Primary Energy Consumption (Btu),
1990-1999. International Energy Annual 1999. Department of Energy.
|[see below]||11.6–12.8 TW|
Humans dominate the Earth in a way that no species has ever done before, and our demands are beginning to place a tremendous strain on the planet's limited resources. Scientists are now asking what can be done to develop a more sustainable way of life before it is too late. The definition of energy supply is the total amount of usable energy available to people. Humans use energy to do work and keep warm. About 95 percent of the energy we use comes from coal, oil, and natural gas which are fossil fuels. Other sources of energy throughout the world include; water, nuclear energy, solar energy, wind power, tides, and geothermal.
Since 1900, the consumption of energy had almost doubled every 20 years. This raise in consumption is due to population increases, the growth of the labor force, increased wealth, energy using invention, etc. This increase in consumption has also created serious problems, such as depletion of fuel reserves and environmental pollution.
Today the human population of earth consumes energy at a rate of about 12.5 TW.
Jennifer Green -- 2001