Natural gas is a fossil fuel, which consists principally of methane. Methane's chemical structure is one atom of carbon surrounded by four atoms of hydrogen. (In Chapter 17, we shall discuss what a splendid fuel hydrogen is.) Methane is rich in hydrogen and poor in carbon, so it is an excellent fuel in that it releases the smallest amount of carbon dioxide per unit of energy delivered of any of the fossil fuels. Thus, using natural gas will contribute least to the greenhouse effect. The actual numbers are 30 percent less than oil and 43 percent less than coal. It has other advantages, producing less carbon monoxide, fewer nitrogen oxide compounds, and less sulfur. Moreover it can be delivered economically to the user without any noxious hydrocarbons, which can be removed by the supplier and sold as feed stock for plastics and other products.
Natural gas is one of the end products of the physical and chemical processes that have produced the oil and coal. It is the gas that creates the gusher when an oil well is opened. Before its value was appreciated, natural gas was flared or burned at the well site (and still is in some countries).
Although natural gas had been used for many centuries, interest in it as an energy source began only at the beginning of the 20th century. An important energy source requires a distribution system which was lacking for natural gas until the 1940s. Pipeline construction began in the United States then and continued into the 1960s. As a result, gas could be easily and cheaply delivered to many remote