Like coal and oil, natural gas is a fossil fuel. Fossil fuels (which we burn to power transportation, heating & cooling, and electricity) are non-renewable sources of energy formed in the earth over the past millions of years, typically from the remains of marine microorganisms and plants. Sealed off from oxygen and put under ever-increasing amounts of heat and pressure, this organic matter undergoes a thermal breakdown process that ultimately converts it to hydrocarbons.
The lightest of these hydrocarbons occur in a gaseous state known collectively as “natural gas,” which in its pure form is a colorless, odorless gas composed primarily of methane.
Natural gas currently supplies nearly 1/3 of the United States’ primary energy and is the primary heating fuel for approximately half of U.S. households.
Natural gas is a growing energy source — generating less carbon dioxide than coal when burned and cheaper than other fossil fuels.
It has been seen by many as playing a strategic role in the clean energy transition — a means to reduce both local air pollution and coal-associated carbon emissions, a means of quick-ramping dispatchable and reliable power, a plentiful, economically-attractive fuel. However, concerns about methane emissions and the overall carbon budget have called into question the future for gas.