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After completing this chapter you should be able to...
- Distinguish among coal, oil, and natural gas and explain how each is formed.
- Describe the processes of mining, processing, transporting, and burning coal to produce electricity.
- Compare the processes of conventional oil and natural gas extraction and fracking.
- Identify the relative contributions of coal, oil, and natural gas to electricity generation in the U.S. and total energy consumption globally.
- Detail the advantages and disadvantages of fossil fuel use.
- Describe strategies to mitigate harm caused by fossil fuel use.
Fossil fuels are nonrenewable energy sources that were formed from ancient organisms. Coal is a solid fossil fuel formed from ancient swamp vegetation. Oil (petroleum) and natural gas both formed from marine microorganisms and are often found together; however, oil is a liquid fossil fuel, and natural gas is in gaseous form.
Coal is produced through surface and subsurface mining. Some oil and natural gas reserves can be recovered through conventional extraction, but unconventional reserves are recovered through hydraulic fracturing (tight oil and natural gas; tight sands) or mining (oil shale and tar sands). To produce electricity from coal or natural gas, the fuel is combusted (burned). The heat is used to produce steam, and the pressure from the steam turns a turbine, which powers a generator. Crude oil must be refined to separate it into a variety of petrochemicals, each with a different use.
Nationally and globally, fossil fuel consumption remains high. Proven reserves of oil and natural gas are projected to last another 50 years while coal reserves are projected to last another 115 years. The U.S. has a large supply of the world's coal but relies largely on imports to meet its oil demands. The world's oil supply is concentrated in OPEC countries, which have great influence over global rates of production.
While existing technologies facilitate continued fossil fuel use, which support local and national economies, fossil fuels cause a variety of health and environmental consequences. Workers and those living near mines or oil refineries are at the greatest risk of health consequences, but combustion of fossil fuels releases air pollutants that harm the general public and native organisms. Furthermore, mining, drilling, and fracking, destroy habitats and release pollutants. Clean coal technologies and reclamation reduces but does not eliminate these negative consequences.
Melissa Ha (CC-BY-NC)