Coal
♫ "Working in the coal mine . . . oh yeah"
Coal still plays a critical role in U.S. and global energy production, but like it's fossil-fuel carbon cousins, oil and gas, it's also a major contributor to air pollution. Burning coal to produce electricity or heat releases large amounts of carbon monoxide, a poisonous gas; nitrogen oxides, the main cause of urban smog; unburned hydrocarbons, the primary producer of ozone; and dozens of particulates that are carcinogenic and contribute to respiratory illnesses, asthma and lots of other bad stuff.
Industry has been forced to use catalytic converters and other technologies to try and reduce much of this pollution, but it's an expensive answer that simply drives up the cost of energy. Coal with fewer impurities is another answer, but that's also more expensive and getting harder to find. Coal has to be mined from beneath the ground, either through surface mining or by digging deep mines under the ground. Then it has to be transported, typically by rail.
A major contributor to our industrial age, coal use diminished in the latter half of the 20th century, but became more popular again as the price of oil and natural gas increased and as fewer nuclear plants were built. In fact, many electrical producers and power companies converted some of their power plants from oil to coal in the late 1970s and '80s. Coal stoves are available for heating homes, and while handling bulky coal is messier than other energy sources, it is easy and safe to store and use.
Much of the coal we use is produced domestically, but it's a finite resource and coal mining remains a highly dangerous occupation and is extremely damaging to the environment. However, it will continue to play an important role as another option in our energy palette.
Understanding the benefits and liabilities of burning coal to produce or release energy is just OneThing you can do in your quest to help conserve resources and reduce our dependence on costly and environmentally damaging energy sources.