The term fossil fuel is used to describe the broad set of fuels “formed in the earth from plant or animal remains” that have been transformed into raw energy sources over the course of many years as a result of geological processes ¹. In effect, fossil fuels are the repositories of millions of years of energy that has been accumulated and shaped into a concentrated form. They are a finite resource that humans were fortunate to discover but whose like they will probably not encounter again. ²

Source: http://earthobservatory.nasa.gov/Library/CarbonCycle/carbon_cycle4.html

Fossil fuels come in three main forms: petroleum, or crude oilOil that has been extracted from the ground but not yet refined into usable form.; coal; and natural gas. All have many uses, but each serves one main purpose. Crude oilOil that has been extracted from the ground but not yet refined into usable form. is refined predominantly to make gasolineA form of highly refined oil that is primarily used to fuel passenger automobiles, especially in the United States. for transportation purposes, while most coal is burned by utilities to produce electricity. Natural gas, not covered in this brief because of space limitations, is mainly funneled to industrial sites and factories, though a sizable percentage makes its way into homes for residential heating ³.

Coal has long been used as an energy source and was the hallmark fuel of the Industrial RevolutionA series of developments in the eighteenth and nineteenth centuries that introduced greater mechanization and the modern urban factory into the industrial economies of many countries in Europe and in the United States.. dIt replaced more traditional sources such as wood (the original biomassliving organisms that be used for fuel or for industrial purposes, or biofuel) and water power (harnessed by mills). The origins of petroleum as an energy source also date from the middle of the nineteenth century, though it did not really come into its own until the automobile became popular in the United States in the 1910s and 1920s. Oil finally overtook coal as the nation’s leading energy source in the early 1950s. Most early oil exploration occurred in North America, though major deposits were quickly discovered in the Middle East ⁴.

In 2009, fossil fuels accounted for approximately 80 percent of the world’s primary energy use, and supplied around 90 percent of the world’s commericial energy. Renewable sources provided around 12 percent of the balance and nuclear power about eight percent ⁵. Within the fossil fuel group, petroleum products accounted for 36 percent of global consumption, coal for 27 percent, and natural gas for 23 percent in 2006 ⁶.

The Role of Renewable Energy Consumption in the Nation’s Energy Supply, 2007

Source: http://www.eia.gov/cneaf/alternate/page/renew_energy_consump/rea_prereport.html

For the United States, in 2010, petroleum products represented 36.2 percent of its fossil fuel mix, coal 21.2 percent, and natural gas 23.8 percent ⁷. Even with the heightened focus on renewable and nuclear power sources, experts predict that fossil fuels will continue to supply the vast majority of the world’s energy needs for much of the next century.

U.S. Fossil Fuel Usage by Sector, 2006

Source: http://www.epa.gov/climatechange/emissions/co2_human.html

1 “Fossil Fuel”

2 Parfit 7

3 “History of Energy in the United States – Petroleum;” “History of Energy in the United States – Natural Gas;” “History of Energy in the United States – Coal”

4 “History of Energy in the United States – Coal;” “Petroleum History”

5 People and Planet Factfile.

6 “World Consumption of Primary Energy”

7 EIA “Monthly Energy Review 2011.”

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