Natural gas is the cleanest burning fossil fuel. When it is burned, it gives off less carbon dioxide than oil or coal, virtually no sulphur dioxide, and only small amounts of nitrous oxides. Natural gas is mostly composed of methane and other light hydrocarbons. Both the carbon and the hydrogen in methane combine with oxygen when natural gas is burned, giving off heat. Coal and oil contain proportionally more carbon than natural gas, therefore giving off more carbon dioxide per unit of energy produced.
Carbon dioxide is the most important greenhouse gas contributing to global warming.
To find oil and natural gas, companies drill through the earth to the deposits deep below the surface. The oil and natural gas are then pumped from below the ground by oil rigs. They then usually travel through pipelines. At oil refineries, crude oil is split into various types of products by heating the thick black oil. The products include gasoline, diesel fuel, aviation fuel, home heating oil, oil for ships, and oil to burn in power plants to make electricity.