Coal is mined from the Earth, which is a dangerous process that can cause respiratory diseases in miners. Natural gas comes from deposits in the earth also. Natural gas is a clean source of energy and requires no further refining once mined from the Earth. Burning fossil fuel produces CO 2 and other atmospheric pollutants such as sulfur. In an effort to reduce atmospheric pollutants many companies have installed filters and other cleaning devices at factories utilizing fossil fuel.
Most water power is used to generate electric power.
Since water power supplies energy without pollution and without using up the water in the process, it is widely thought to be the best source of power, however, the dams used to produce this power cause irreversible damage to the surrounding ecosystems both up and down stream, threatening and possibly eradicating plant and animal species. Nuclear energy provides another 6 percent of our energy. Fission is the process of splitting atomic nuclei of certain elements such as uranium. This process produces hot waste water that may damage the environment and also produces waste that must be isolated to protect the environment. To reduce the thermal pollution, most new nuclear power plants have large water cooling devices.