Fossil Fuels

Fossil fuels, deriving their name from the ancient remains of organic matter from which they are formed, represent the major energy source in the world today. A nonrenewable resource, fossil fuels exist in finite amounts in the earth's crust. The most widely extracted and economically viable fossil fuels are coal, petroleum (crude oil), and natural gas. All fossil fuels began as living plants and cellular animals; petroleum as microscopic plants and bacteria, [Page 707]natural gas as plankton and algae, and coal as more dense and fibrous trees and ferns. When these living organisms died, they settled to the bottom of the seas (in the case of oil and natural gas) and swamps (in the case of coal). Over many millions of years, layers of sedimentary material settled above this organic material. As the immense weight of the above-lying sediments increased over time, the resulting pressure and heat transformed the organic source materials into hydrocarbons. These hydrocarbons, forming the basis of all fossil fuels, have a molecular structure made up of mainly carbon and hydrogen.

Today, the vast majority of the world's energy comes from burning hydrocarbon-based fossil fuels. In the United States, for example, 85 percent of consumed energy comes from fossil fuels. Throughout the world, coal, oil and petroleum-based products (like gasoline and jet fuel), and natural gas provide the energy that powers agricultural and industrial production, modes of transportation, and electricity generation enabling lighting, heating, and cooling of homes and businesses.