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AP Enviro



Unit 6

6.5 Fossil Fuels

2 min readfebruary 6, 2021

Karla Jauregui Sandoval

Fossil Fuels

The world is dependent on fossil fuels because they are easy to access. The three main types of fossil fuels are coal, oil (petroleum) and natural gas. 

  • Coal ➱ Formed from millions of year of decomposed plant buildup, coal is made of of carbon, hydrogen and water 

  • Oil ➱ Formed from millions of year of heat and pressure of aquatic organisms, oil is made up of carbon and hydrogen 

  • Natural Gas ➱ Formed from plant and animal organic matter trapped under a sedimentary layer of Earth’s layer, natural gas is made up mostly of methane (CH4)

Combustion of Fossil Fuels 

Fossil fuel combustion is the process of a fuel type reacting with heat and oxygen which leads to chemicals, light and energy being released. Complete combustion releases non-toxic chemicals such as water vapor and heat however in majority of the cases incomplete combustion occurs. 

Natural Gas Combustion 


Methane Combustion 


Coal Combustion 


Hydraulic Fracturing 

Hydraulic Fracturing is a process that involves drilling through rock to unlock oil and natural gas in the ground. As mentioned, gas is formed on top of layers of dead organisms that over time have been exposed to pressure. 

Hydraulic factoring involves steel cement pipes that pump out fluid. The fluid opens up fractures in the shell, water, sand, and surface. The sand for example allows the oil to go up. As the wheel reaches its kickoff point then that is well the horizontal drilling of the holes allows the oil to escape through the cracks.

Image Courtesy of Mother Earth News


Risks of hydraulic fracking include: 

  • Contaminating underground drinking water 

  • Increases threat of earthquakes which puts infrastructure at risk 

  • Methane is released during drilling 

  • Natural gas supplies are nonrenewable 

Impact of Fossil Fuels 

An impact of the production and combustion of fossil fuels is the byproduct of sulfur dioxide, nitrogen oxide, and carbon dioxide. 

  • When coal is burned it releases CO2, nitrogen oxides, and sulfur dioxide. Coal combustion also leads to particulates that contribute to pollution of the atmosphere.  As a result of these pollutants being produced, acid rain forms. Acid rain is comprised of any type of precipitation, wet or dry, that combines atmospheric pollutants with water droplets, such as snow and hail.

  • The use of oil pollutes the environment through the burning of petroleum, which creates and releases greenhouse gases. Oil is not a clean source of energy as it is contributes to the rapidization of global warming due to the release of toxic gases such as carbon monoxide. 

    • Another impact of oil is the risk of oil spills which are difficult to clean up and can harm marine life at devastating levels. 

    • Oil is a non-renewable energy source because the pace at which petrol replenishes will not be nearly high enough to satisfy increasing demand.

    🎥 Watch: Environmental Science


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