Climate Change and Environmental Analysis

Fact Sheet May 03, 2007

Natural Gas is the Cleanest and Most Efficient Fossil Fuel

Natural gas, the cleanest fossil fuel, is a highly efficient form of energy.  It is composed chiefly of methane; the simple chemical composition of natural gas is a molecule of one carbon atom and four hydrogen atoms (CH4).  When methane is burned completely, the principal products of combustion are carbon dioxide and water vapor.

Natural gas has fewer impurities, is chemically less complex and its combustion generally results in less pollution than other fuels. In most applications the use of natural gas produces less sulfur dioxide (the primary precursor of acid rain), less nitrogen oxides (the primary precursor of smog) and less particulate matter (which can affect health and visibility) than oil or coal. Technological progress allows cleaner energy production today than in the past for all fuels, although the inherent cleanliness of gas means that environmental controls on gas equipment, if any are required, tend to be far less expensive than controls for other fuels.

Comparison of Air Pollution From Fossil Fuels

(Pounds of air pollutants produced per billion Btu of energy)


Natural Gas    



Carbon Dioxide




Source: Energy Information Administration

Using more natural gas to replace dirtier fuels can help address simultaneously a number of environmental concerns, like smog, acid rain and greenhouse gas emissions.

Natural gas is highly efficient.  About 90 percent of the natural gas produced is delivered to customers as useful energy.  In contrast, only about 27 percent of the energy converted to electricity reaches consumers.

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