Coal, a black or brownish-black sedimentary rock, is the most abundant fossil fuel on earth. It takes millions of years to develop, and is, like other fossil fuels, created from the remains of ancient organisms.
Utilized, since the cave man, for heating and cooking, it was also used in the Roman Empire to heat public baths and, during the Aztec Empire, as a decorative ornament.
Currently, coal is extracted from the earth either by surface or underground mining. Once extracted, composed mostly of carbon and hydrocarbons, the energy it contains can be released through combustion (burning) either directly (for heating and industrial processes) or to fuel power plants for electricity – close to 90% of U.S. coal consumption is in the electric power sector.
Currently mined in 25 states, the U.S., with one of the world’s largest coal reserves, has (as of July, 2020) 263 operating coal-fired power plants, having retired 288 over the ten previous years.
The first one was in lower Manhattan, which began operation in September, 1882. Later that same month, the country’s second commercial power plant was a hydropower plant in Appleton, Wisconsin. Within three years, coal became the most-used energy source in America, overtaking renewables including hydropower and wood.
By 2019, U.S. coal-fired electricity generation had fallen to a 42-year low with annual energy consumption from clean energy sources exceeding coal consumption for the first time in more than 100 years. This was mainly the result of growth in gas plants and renewable energy.
To add insult to injury — just in the year 2019 over 2018 — the decline was so significant that coal consumption in the United States decreased nearly 15%. Despite its decline it remains, however, the dominant CO2 emissions source related to electricity generation — accounting for 60% of the electric power sector CO2 emissions in 2019.
Coal has always been plentiful and cheap, as fossil fuels go, before gas became cheaper and renewables more available. The reduction of our reliance on coal is fortunate in so far as toxins and greenhouse gases, such as carbon dioxide, are concerned. Extraction and burning releases the highest levels of pollutants into the air including sulfur dioxide, another pollutant gas that causes respiratory problems, damages crops, forests and lakes.
Surface mining also permanently alters the landscape. In mountaintop removal, the landscape itself is obliterated and ecosystems are destroyed. This increases erosion in the area. Streams may be blocked, increasing the chances for flooding. Toxins often leach into groundwater, streams, and aquifers.
Coal is one of the most controversial energy sources in the world. The advantages of coal mining are economically and socially significant. And, yet, mining devastates the environment: air, land, and water. Coal combustion is, by far, the nation’s primary culprit of global warming.