From Ecopedia

Overview

Fossil Fuels are non-renewable gas fuels formed from the fossil remains of dead animals and plants such as zooplankton and phytoplankton that settled to the lake or sea bottom millions of years ago. Such fossilized remains, containing large quantities of carbon and hydrocarbons provide rich source of energy.

Ever since the days of Industrial Revolution, fossil fuels formed rich natural source of energy. Through simple direct combustion of fuels, energy was easily generated for use in wide variety of applications. Fossil fuels range from nonvolatile materials such as anthracite coal, containing almost pure carbon to liquid petroleum to volatile materials made up of low carbon-hydrogen ratios that include methane.

Global Consumption Levels

Fossil fuels such as coal, oil and natural gas meet most of the primary energy needs of the world. As per current global estimates, Natural gas is accounting for about 20% of global energy consumption, while coal is accounting for 27.4% and oil, particularly petroleum, is accounting for 36% of the worldwide energy consumption. On the other hand, in recent times, heavy crude oil, tar sand and oil shale are gaining prominence and are becoming important fossil fuel sources. Global energy estimates show that more than 85% of worldwide energy demands are met by fossil fuel combustion.

Environmental Impacts

At present times, fossil fuel production and use is raising serious environmental concerns. In order to combat the ever-increasing environmental footprint of the fossil fuels, a global move towards renewable energy generation is currently underway. As fossil fuel reserves are fast depleting, alternate energy sources that are more eco-friendly are being increasingly considered for energy generation.

Eco-balance and Global warming

Ongoing excavation of fossil fuels from the earth’s surface, on the one hand is permanently altering the ecological balance of the earth. Fossil fuel combustion, on the other, is leading to release of large quantities of greenhouse gases including carbon dioxide, methane and nitrous oxide, causing global warming.

Fossil fuel combustion annually produces 21.3 gigatonnes (21.3 billion tonnes) of carbon dioxide, of which only half of the amount is being absorbed by the natural processes, resulting in 10.65 billion tonnes net increase of the gas every year.

Besides global warming, Carbon dioxide is found to harm the environment by enhancing radiative forcing.

Acid Rain

Fossil fuel combustion leads to generation of carbonic, nitric and sulfuric acids, which precipitate environmentally-harmful acid rains. Acid rains affect the natural environment and wild life. Radioactive Release

Fossil fuels containing thorium, uranium and other radioactive materials, release the substances into the atmosphere during combustion. In 2000, coal combustion caused around 5,000 tonnes of uranium and 12,000 tonnes of thorium to be released globally.

Coal Mining

Various coal mining methods such as strip mining and mountaintop removal as well as offshore oil drilling pose environmental hazards. Offshore oil drilling is found to harm aquatic life significantly.

Oil Refineries

Oil refineries cause water and air pollution, showing negative impact on the environment. Crude oil transportation through tanker ships, requiring additional burning of fossil fuels, leads to faster fuel depletion.

References

http://library.thinkquest.org/20331/types/fossil/ http://fossil.energy.gov/ http://www.financialexpress.com/news/world-fossil-fuel-energy-use-growing-study/293313/ http://www.merriam-webster.com/dictionary/fossil+fuel http://www.myclimatechange.net/default.aspx?Page=Article&SubjectId=25&cat=1&sub=1 http://en.wikipedia.org/wiki/Fossil_fuel http://www.umich.edu/~gs265/society/fossilfuels.htm http://www.darvill.clara.net/altenerg/fossil.htm