Natural gas, is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.
The replacement of coal with natural gas for electricity generation has long-term climate benefits since natural gas combustion produces less carbon dioxide (CO2) per unit of energy generated than coal. However, methane (CH4), the primary constituent of natural gas, is a powerful greenhouse gas with 120 times the radiative forcing of CO2 on a mass basis (IPCC, 2013). Methane has an effective atmospheric lifetime of approximately 12 years while a large portion of CO2 emissions persists in the atmosphere for much longer.
Natural gas is a non-renewable hydrocarbon used as a source of energy for heating, cooking, and electricity generation. It is also used as a fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals