Coal: The Dirtiest Fuel

Originally printed on COEJL

By Benjamin Kahane

Depending on how much pressure and temperature to which it has been subject, coal is a sedimentary or metamorphic rock comprised mostly of carbon. Coal is a fossil fuel used primarily in the generation of electricity. To turn coal into electricity, the rock is pulverized then combusted in a furnace, the heat from which converts water into steam used to spin turbine blades to create electricity.

Coal is mined from the Earth in one of two basic methods: surface mining and underground mining. Surface mining — or strip mining — is the most economical way to extract coal if it is located close to the surface; it’s also the most ecologically devastating method, since the surface of the land, complete with trees, topsoil and all plants, are removed. This method is particularly common in the Appalachian Mountains, where the entire tops of mountains are removed, with debris pushed into valley streams.

Underground mining accounts for about 60 percent of world coal production and is the preferred method when the coal seams are too deep or the land is protected. Strip mining accounts for the remaining 40 percent. However, in the United States the numbers are reversed, and surface mining dominates.

There are many negative environmental impacts to using coal. Although coal is comprised mostly of carbon, smaller quantities of sulfur, hydrogen, oxygen, nitrogen, and other heavy metals including mercury also exist in the coal we burn. There are higher and lower qualities of coal, just like petroleum, however the use of lower quality coal is widespread due to more widespread availability. If these harmful byproducts are not removed before or during combustion, they can lead to damaging events such as acid rain, background radiation exposure and cancer in humans and animals. Carbon dioxide emissions are also a cause for concern since carbon dioxide is a major contributor to climate change.

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