Fossils fuels come from plant and animal matter that died millions of years ago. Soil and sediment built up over time, putting pressure on the material and forcing oxygen out. This plant matter turned into kerogen, which becomes oil as it warms up to 110 degrees Celsius. Natural gas then forms from oil at temperatures above 110 degrees Celsius.
The majority of all mining for fossil fuels involves the extraction of coal. Coal can be extracted close to the upper portion of the earth's crust, called surface mining, or from deep within the earth through underground mining. Recovering coal through surface mining is relatively easy; shovels and bulldozers are effective at extracting coal near the surface. Once depleted, workers replant a surface mine and move on.
Offshore oil rigs and on shore oil derricks pump most of the petroleum that is extracted throughout the world. A hole is drilled into a potential oil patch and the oil is pumped out through a long tube. In the United States, the major oil producing states are located along the coast, according to the Energy Information Administration
Natural gas and petroleum are often found in the same patch of land. Scientists look for gas and oil deposits with special equipment that causes a vibration in the ground as certain frequencies are associated with oil and gas. Pumps then separate oil and gas on site. New technology, called "digesters," can create natural gas from plant matter by simulating and speeding up the natural process.
The Environmental Protection Agency currently believes that the burning of fossil fuels contributes to global warming. Fossil fuels emit carbon dioxide when burned, a gas that traps heat below the earth's atmosphere, causing a greenhouse effect. Current studies show that the world releases too much carbon dioxide, which could warm the earth in a relatively short span of time.