Coal is used in many industrial processes, and by electric power plants. Accounting for 18 percent of the energy consumed in the U.S. in 2012, according to the Center for Climate and Energy Solutions, coal is used to generate 44 percent of electricity produced in the country (per the Union of Concerned Scientists). It also supplies nearly 30 percent of energy use worldwide and accounts for 44 percent of the CO2 emitted into the air around the globe.
Coal mining has detrimental impacts on human health, the environment, and water supplies. Here are 15 important facts related to coal mining and burning that cannot be ignored.
Types of Coal Mining
1. Different types of coal are used depending on the amount of heat released when it is burned. How much heat released is determined by the levels of carbon, oxygen, and hydrogen. Brittle and glassy, Anthracite is 86 to 97 percent carbon and yields almost 15,000 BTUs per pound. Bituminous coal is the most commonly used type of electric power (accounting for over 45 percent of U.S. coal production in 2010); a softer variety, it contains anywhere from 45 to 86 percent carbon content. Sub-bituminous coal is also used and has a carbon content of up to 45 percent. Suited for electric power and synthetic gas production, lignite can be up to 35 percent carbon.
2. Coal is mined directly from the surface if deposits are less than 200 feet down. The recovery ratio for a surfaced mine can be over 90 percent. Underground mines are dug to access coal formations hundreds of feet below the surface but allow for recovery of less than 40 percent of the coal there.
3. Coal mining contributes to global warming because it releases up to 3.7 million tons of carbon dioxide, a leading greenhouse gas, every year. This is in the U.S. alone, where there were no regulations limiting how much CO2 is released until new Environmental Protection Agency regulations were introduced in 2015, which set limits on how much coal and other power plants can emit. For coal plants, the top end is 1,400 pounds of CO2/megawatt-hour.
4. Coal burning also releases 10,000 tons of sulfur dioxide per year, which causes acid rain, and 10,200 tons of nitrogen oxide, also a contributor to acid rain in addition to smog. Tons of hydrocarbons are released into the air and small particles are emitted as well, which are less than 10 microns in size and can cause major lung damage if inhaled.
5. Locomotives transport coal by rail from many plants and a typical plant uses 40 railroad cars. Using diesel fuel, these emit close to a million tons of nitrogen oxide every year in the United States, plus 52,000 tons of additional particulates that blow through the air as coal dust.
Other Pollutants and Heavy Metals
6. Smokestack scrubbers from coal plants produce up to 125,000 tons of ash and 193,000 tons of sludge. They use powdered limestone and water to remove pollutants from the exhaust, but these go to landfills, where toxic metals such as lead and mercury may be introduced. Sometimes, ash and sludge are used to make concrete and drywall, taking these pollutants with them.
7. Toxic metals released from coal plants include arsenic, lead, and cadmium. Mercury has been a problematic pollutant connected with coal production. It has been identified in lakes and rivers in Wisconsin, and bodies of water in other northern and northeastern states, as well as in Canada.
8. Most naturally occurring elements have been found in coal, including uranium. Traces of this radioactive element have been found through coal combustion in greater amounts than when producing nuclear power, according to a Department of Energy study at Oak Ridge National Lab. Researchers have detected less than 1 part per million of uranium to about 10 parts per million. There is also 2.5 times more thorium than uranium in coal.
9. Typically, a coal plant takes between 70 and 180 billion gallons of water from lakes, rivers, and oceans, and consumes up to 1.1 billion gallons of that. Plants with once-through cooling systems withdraw more water, but even a plant with a wet-recirculating cooling system can consume up to 4 billion gallons every year. Dry-cooled coal plants consume less.
10. Young and adult fish, fish eggs, and larvae are drawn into intakes by the millions. Those trapped are often injured or killed before they can escape.
11. An integrated gasification combined-cycle can reduce water consumption in coal plants by 35 to 60 percent. The technology is currently being commercialized and can also reduce the number of pollutants released into the air.
12. Around the world, there are over 8,000 coal-burning power plants. The amount of water they use is enough to serve one billion people. Water goes toward maintaining boilers and handling coal ash. Even plants that use seawater use a substantial amount of fresh water in their processes.
13. The largest source of carbon dioxide emissions is coal burning, according to Greenpeace. A 500 MW coal power plant can release 600,000 cars worth of emissions and may operate for at least 40 years. Methane, another greenhouse gas, is 84 times more powerful at affecting the climate. At the current pace of growth, the organization says, coal will account for 60 percent of CO2 emissions by 2030.
14. Dust can blow from piles of burned coal, usually stored outdoors on the site of a power plant. It can settle in nearby houses, soils, and backyards. When it rains, this dust can run off and further contaminate land and water.
Illnesses and Injuries
15. According to the Bureau of Labor Statistics, the coal mining industry has nearly six times the rate of fatal injuries compared to other private industry sectors. In 2007, 20 of the 28 reported fatalities were related to underground bituminous coal mining. Most fatal injuries resulted from transportation mishaps and injury from objects and equipment. In 2008, non-fatal injury and illness rates were 13 percent higher than for private industries in general.
Mining and burning coal, therefore, don’t just pollute the air, water, and land; they also jeopardize human health and contribute to excessive resource consumption and climate change.