Fuel: Material such as coal, gas, or oil that is burned to produce heat or other forms of energy.
Fossil Fuel: A natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
Combustion: Rapid chemical reaction of a substance with oxygen, producing heat and light. Complete combustion: Combustion in which all of the fuel is reacted with oxygen. Complete combustion of most fuels produces CO2, and H2O2.
Incomplete combustion: Combustion which occurs with a limited supply of oxygen. Incomplete combustion produces carbon monoxide, carbon (soot), and water.
Respiration: The processes whereby some organisms obtain energy from food. Usually requiring oxygen and producing carbon dioxide and water.
Renewable: A source of energy that is not depleted by use, such as water, wind, or solar power.
Non-renewable: A natural resource which cannot be produced, grown, generated, or used on a scale which can sustain the rate it which it is used. Climate: The weather conditions prevailing in an area in general or over a long period.
Greenhouse Effect: A process by which radiative energy leaving a planetary surface is absorbed by some atmospheric gases.