Earth Science

Natural Resources

Fossil Fuel Reserves

Study Tip
Break down the term “fossil fuel” to better understand its meaning. Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms, or fossils.

Fossil Fuel Reserves

  • Fossil fuels provide about 85% of the world’s energy at this time
  • Worldwide fossil fuel usage has increased many times over in the past half century, because of…
  • Population increases
  • Increases in the number of cars, televisions, and other fuel-consuming uses in the developed world
  • Lifestyle improvements in the developing world
Study Tip
Break down the term “fossil fuel” to better understand its meaning. Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms, or fossils.
Study Tip
The same way a person may cast a shadow over another person when they stand under the sun, planets or celestial bodies that have aligned themselves cast shadows over one another as well.
  • The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal

Alternative Fossil Fuels

  • As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited
  • Oil shale is rock that contains dispersed oil that has not collected in reservoirs
  • Tar sands are rocky materials mixed with very thick oil
  • Development of alternative energy sources is favorable, for the following reasons:
  • Environmental consequences of mining fuels
  • Fuels do not have a limitless supply
Worldwide oil reserves
Worldwide oil reserves.
Concept Check
  • What are oil shales and tar sands?
  • How do scientists and politicians determine how much fossil fuel is left? Why is this number undoubtedly inaccurate?
  • Why is the need for fossil fuels increasing?