The chemical formula for methane is CH4. This is the simplest example of a class of compounds called hydrocarbons. Methane occurs in nature, formed from breaking down plant material, in the digestive process in animals and in fossil fuel deposits.
Methane, also called natural gas, forms from the bonding of four hydrogen atoms to a single carbon atom. The hydrogen and carbon atoms share electrons to fill their outer energy levels, producing a more stable configuration for both hydrogen and carbon.
Methane is a greenhouse gas. Greenhouse gases travel into the atmosphere, trapping the sun's heat on Earth like the glass on a greenhouse. The trapped heat causes global temperatures to rise slowly. Methane is one of the culprits leading to the phenomenon of global warming.