How can coal mining harm the environment?
Coal mining harms the environment in multiple ways. Like other fossil fuels, the burning of coal releases carbon dioxide into the environment, which is the main cause of climate change. Before this can even happen though, coal must be extracted.
Mining in general greatly alters the environment. For coal to be extracted from the earth, whatever ecosystem is on top of the earth needs to be removed. This could be a forest or other ecosystem. Either way, it must be cleared before mining can begin.
Coal mine in West Virginia, USA:
Surface mining, which includes strip mining and open pit mining, removes the top soil of the earth, but this type of mining usually covers very large areas of land. Vegetation is lost and the soil removed needs to go somewhere else. Sometimes, the removed soil (also called overburden) is dumped elsewhere, which negatively impacts that ecosystem.
Coal may be mined through mountaintop removal, a process during which removes a substantial portion of the top of a mountain in order to extract the coal. This process significantly alters the environment.
Underground coal mining is done when the coal deposit is at a greater depth. If done incorrectly, this type of mining may impact groundwater.
Impurities removed from coal and mining waste need to be stored somewhere, and they are usually stored in reservoirs. Some contaminants may leach into the surrounding soil and groundwater. These reservoirs have been known to break with disastrous consequences.
Rupture of coal ash reservoir in Tennessee, USA:
Acid mine drainage is also a large problem. Mining may expose heavy metals, which dissolve and seep into the groundwater or surface water used by plants, animals, and humans. When it rains and the water falls over the exposed rocks, the runoff may become acidified.
Acid mine drainage: