Methane is a chemical compound with the chemical formula CH4 (one carbon atom bonded to
four hydrogen atoms). It is a group‐14 hydride, the simplest alkane, and the main constituent of
natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel,
although capturing and storing it poses technical challenges due to its gaseous state under normal
conditions for temperature and pressure.
Naturally occurring methane is found both below ground and under the seafloor and is formed by
both geological and biological processes. The largest reservoir of methane is under the seafloor in
the form of methane clathrates. When methane reaches the surface and the atmosphere, it is known as atmospheric methane.