- Fossil fuels are fuels formed from the decomposition and compaction of plant and animal remains of the prehistoric age. The common fossil fuels are Coal, Crude Oil and Natural Gas. Other widely used fossil fuels are oil sands (in Canada, Russia, South Arabia etc) and Oil Shale (mostly in the United States of America). These fuels are buried far deep below the ground. A lot of effort is required first to discover where these fuels are buried (exploration) and secondly to "mine" or "dig out" or "pump out" these resources. They have been the World's main source of energy for centuries.

These fuels are burned in power plants to provide energy required to power the energy plants. However, due to concerns about the negative impact of these fuels on the environment, there is a recent shift towards using cleaner and renewable energy sources for the following reasons:

• Fossil fuels RELEASE POLLUTANTS to the environment. When burnt, they release pollutants like CO2 that contribute to global warming; NOX and SO2 that produce smog and contribute to acid rain.
• Fossil fuels are NON-RENEWABLE. The fossil fuels we are using now, took long periods of time to form (according to scientists). When we use up what we have now, we cannot replace them within our life time or within the life time of the several generations to come. The result will be serious energy crisis.
• Alternative energy sources that can be easily reproduced within short periods of time are required.
• Fossil fuels have been sources of SECURITY treats to many advanced economies of the world, who depend on less stable countries for fossil fuel supplies.

Some technologies such as Carbon Capture and Storage (CCS) have been suggested to make the burning of fossil fuels (particularly coal) cleaner. However, very little can be done to lessen the impacts of non-renewable and security concerns of fossil fuels.

Alternative energy sources (which are renewable and/or reduce or eliminate GHGs generation) are being researched constantly. Some of these alternative energy sources include:

• Solar Energy – energy from the Sun;
• Wind Energy – energy due to wind motion;
• Hydrogen Energy;
• Hydroelectric power, and
• Geothermal energy

Nuclear power (though not a renewable energy source) and Clean Coal Technologies are other alternative energy sources. Full list of the energy sources are contained in the left panel of this page. Follow these links to learn more about the energy sources.

Other Resources:

• Energy Resources - Contain information about various forms of energy
• Department of Energy - Energy Sources - United States Department of Energy
• The Energy Story - California Energy Commission
• EIA Energy Kids - Energy Kids: Energy Information Administration - United States Environmental Information Administration
• Sources of Renewable Energy - Website of the Pembina Institute