Extraction
Before extraction, an area must be located with ample coal supplies. Generally coal is only mined from proven reserves where there is certain to be coal. The proven reserves of coal that can be easily mined are not evenly distributed. In fact, the United States, Russia, China, and India have approximately 66% of the worlds proven reserves. Once a suitable location has been identified the extraction process can begin. The extraction of coal is a very dirty process. There are two main ways coal is mined out of the ground. There are underground shaft mines or open pit mines. Each has its own detriments and positives.
Underground Shaft Mines
These are your traditional mines. They are dug deep into the ground and have shafts extending out to reach as much coal as possible. Once the coal has been mined it is transported out of the mine and distributed. Many times the coal is processed with chemicals to insure a purer product, resulting in tailings. These tailings can contain toxic metals that can pollute local waters. The chemicals used in processing are sent to a disposal plant or are pumped into old shaft mines. One major draw back is the lack of ventilation. Due to this many miners develop a condition called black lung, caused by breathing the lingering coal dust in the air. There is also danger from hitting natural gas pockets. If too much gas gets into the mine shafts then the miners could suffocate. If that does not happen then even a small spark could set the gas ablaze, resulting in fires that can last centuries. This is why many miner would carry canaries into coal mines. If the canary died then there was gas in the mine. Even once the mine has been depleted and abandoned there can still be environmental consequences. Acid mine drainage occurs when chemical compounds exposed by mining are dissolved into water and drained out of the mine. This water then acidifies the surrounding waters it comes into contact with. A positive is that there is minimal damage to the surrounding ecosystem, as all the mining done underground.
Open Pit Mines
These mines require lots of heavy machinery to operate. They are created by digging off all of the soil and rock, called the overburden, above the coal. Once the coal is exposed it is then dug out, leaving a huge hole. Mountain top removal is a process the same as this except with a mountain being the target of over burden removal. Once exhausted the land is generally restored, at least as much as it can be. There are numerous problems with this style of mining, the first of which is the machinery required for operation. Usually all the equipment is very large, requiring lots of fuel to operate. This means lots of carbon dioxide is released into the atmosphere. There is also a danger to miners of being crush by the equipment, although this way of mining is less harmful to workers. The over burden may cause water contamination if it contains harmful toxins. Also like in the other method the coal is processed with chemicals that are sent to a disposal plant or pumped into nearby old shaft mines. Even so the biggest drawback is the destruction valleys of ecosystems. In pit mines and mountain top removal, the entire ecosystem is removed from the site. This is an extremely big problem in the Appalachian mountains where the destroyed ecosystem is pushed into the valleys around the mountain, killing everything in and around the mountain. This includes several endangered species of newts. Even if the site is restored with soil, it will have go through secondary succession and never house the same species as before. There is also problems with acid mine drainage when the mine is abandoned.