Last updated on: 2/27/2009 | Author:

What Are Fossil Fuels?

General Reference (not clearly pro or con)

The US Department of Energy’s Energy Information Administration provided the following definition of “fossil fuel” in the “Glossary” section of its Feb. 2005 “Voluntary Reporting of Greenhouse Gases” report available online at its website:

Fossil fuel: An energy source formed in the Earth’s crust from decayed organic material. The common fossil fuels are petroleum, coal, and natural gas.”

Feb. 2005

The Tyndall Centre for Climate Change Research wrote in its Oct. 2005 study “Surviving Climate Change in Small Islands: A Guidebook,” published on its website:

“Fossil fuels are concentrated deposits of carbon stored underground or beneath the sea. They are composed of the fossilised remains of plants and animals, which have decayed over millions of years, slowly being converted to fuel which can be extracted from the Earth millions of years later. This stored energy in the form of coal, oil and natural gas can be used as fuel when it is burned.”

Oct. 2005

The Consumer Energy Council of America wrote the following in its fact sheet “Fossil Fuels,” published on its website (accessed Oct. 22, 2008):

“Coal and petroleum and their derivatives are known as ‘fossil fuels’ because they were formed from the decomposition of organic compounds (dead bodies of plants and animals) during the carboniferous period, 280 to 345 million years ago. High heat and pressure from the Earth’s core caused the decaying matter to turn first into a spongy-textured substance called peat and then into either a hard, carbon-rich rock (coal) or a liquid (petroleum).”

Oct. 22, 2008

The Arizona Mining Association wrote in its article “Out of the Rock: From the Ground Up,” published on (accessed Oct. 22, 2008):

“The three most common fossil fuels are coal, oil, and natural gas. They are derived from once living organisms, and they can be processed to yield energy. Strictly speaking, none of these substances are true minerals. Coal lacks the crystal structure of minerals and is chemically heterogeneous; true oil is a liquid, and natural gas is gaseous…

Coal is made from plant remains and is used in the production of electricity and chemicals as well as in the steel-making process…

Oil is formed from the remains of free-floating planktonic organisms which live in the open ocean. As sediment, rich in these organisms, is buried and compacted, the organic matter is altered. Near the surface, bacteria turn some of the organic matter to methane (natural gas). Deeper burial temperatures of 50° to 150°C promote the formation of oil.”

Oct. 22, 2008

The National Petroleum Council wrote the following in its July 2007 report “Hard Truths: Facing the Hard Truths about Energy,” published on

“Fossil Fuel is a collective term for hydrocarbons in the gaseous, liquid, or solid phase. The global fossil fuel endowment includes the following: coal, crude oil (including condensate), natural gas liquids, and natural gas.

Coal is the altered remains of prehistoric plants that originally accumulated in swamps and peat bogs. It is organic sedimentary rock that has undergone various degrees of coalification, which determines its current physical properties.

Crude Oil is defined as a mixture of hydrocarbons that exists in a liquid phase in natural underground reservoirs and remains liquid at atmospheric pressure after passing through surface production facilities.

Natural Gas Liquids (NGLs) are those portions of the hydrocarbon resource that exist in gaseous phase when in natural underground reservoir conditions, but are in a liquid phase at surface conditions (that is, standard temperature and pressure conditions: 60ºF/15ºC and 1 atmosphere).

Natural Gas is a mixture of hydrocarbon compounds existing in the gaseous phase or in solution with oil in natural underground reservoirs at reservoir temperature and pressure conditions and produced as a gas under atmospheric temperature and pressure conditions. Natural gas is principally methane, but may contain heavier hydrocarbons (such as ethane, propane, and butane) and inert compounds.”

July 2007