The materials that contain this stored carbon are coal, oil, peat and natural gas.
The collective term for these four materials is Fossil fuel , decomposing fungi, bacteria, and worms.
Many of the carbon based fuels are categorized as fossil fuels because they formed from the decayed organisms over millions of years. Fossil fuels are the buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of millions of years.
