Source
Fossil fuels are energy sources that come from the Earth, such as coal. These substances were formed by decomposing compounds from millions of years ago, such as the organic remains left behind by plants and animals.
Types
Fossil fuels include coal, petroleum, natural gas and crude oil. Uses for some of these are still being developed; natural gas was once a waste product that was produced during refinement of petroleum, and is now an important resource in itself.
Effects
Most of the greenhouse gases that are now causing havoc in the environment come from the burning of fossil fuels. The mining of fossil fuels also has had a negative impact on the environment; processes such as oil drilling and strip mining have destroyed countless miles of land and ocean.
Future
Fossil fuels will run out--unlike wind or solar power, they are not available in unlimited forms. These substances are being mined and burned much faster than they are being produced. Scientists across the world are searching for other, cost-effective alternatives.
Time Frame
Many fossil fuels are created from materials from the carboniferous period of the Earth's history--between 280 and 345 million years ago--in a process using heat and pressure similar to the creation of a diamond.
Precautions
Laws are being passed in order to limit and control the amount of fossil-fuel contaminants that are being released into the atmosphere with the hope of heading off the consequences of air pollution, including global warming.
Turn Your Lights Off
The majority of electricity--up to 87 percent--is created from the burning of coal. Most petroleum is used in transportation.