Natural gas is a non-renewable source of energy and is a fossil fuel like petroleum. It is essentially composed of methane, which is a hydrocarbon. Before processing, it may have other hydrocarbons, such as butane and propane. Natural gas is odorless and it is therefore required by law to add an odorous substance to help detect it in case of leaks. Usually Mercaptan is added, which gives a pungent smell.

Industries, commercial establishments, and residences use natural gas. In the US, 25 percent of the energy demand is satisfied by natural gas. It is used primarily for heating and cooking purposes. More than 62 million homes use natural gas for their home heating requirements. Hence, the demand surges in winter for heating purposes. In industries, it is used to produce electricity and industrial heating. Industrial demand is dependent upon various factors such as crude oil availability.

According to the Energy Information Administration, the total production in the US was 19 trillion cubic feet of gas in 2004. The total consumption was 23 trillion cubic feet of gas. The shortfall is met by imports, mostly from Canada and Mexico. Natural gas is imported through tankers in a liquefied form as Liquefied Natural Gas (LNG), and it is converted back to gaseous form before transmission. A small proportion of the production is also exported to other countries.

Natural gas burns cleaner than other fossil-based fuels and emits lower levels of sulfur, and hence is the preferred fuel for electricity-producing companies. Being a fossil fuel, it has a greenhouse effect on the environment. Natural gas has safety hazard, as it can easily catch fire. In fact, the law to add an odorant was prompted by an accident in a high school in Texas in the nineteenth century.

The availability of natural gas is dependent upon the capacities of oil and gas fields at onshore and offshore locations. The US faces a serious but surmountable challenge to meet the demand supply gap.