Natural gas, a highly flammable fossil fuel, is an important nonrenewable energy resource. Less polluting than other fossil fuels like coal and oil, natural gas is deemed relatively environmentallyfriendly, helping to increase demand for the fuel in [Page 1216]recent years. As a hydrocarbon, natural gas is primarily composed of methane, a colorless, odorless, lighter-than-air gas.

Methane is the simplest of all the hydrocarbons in molecular makeup, consisting of one atom of carbon and four atoms of hydrogen. While natural gas is relatively clean-burning, methane itself is a greenhouse gas, more efficient at trapping heat than even carbon dioxide (the major offending gas in the enhanced greenhouse effect). Burning natural gas, as with all hydrocarbons, releases carbon dioxide into the atmosphere. Increased levels of methane and carbon ...