Throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and/or heat, and is also used for industrial purposes, such as refining metals. A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over a long period. The United States Energy Information Administration estimates coal reserves at 7011948000000000000♠948×109 short tons (860 Gt). One estimate for resources is 18,000 Gt.
The Independent | 18 Jan 2021