Fossil fuels
Fossil fuels include coal, oil, and natural gas. They occur naturally in the Earth, and can be burned for energy. They currently provide over 80% of the world's energy, but at a heavy environmental cost.
Terminology
- Natural gas is sometimes referred to as just gas. Not to be confused with gasoline.
- Crude oil is also known as petroleum, and it can be refined into oil products such as gasoline and diesel.
Usage as an energy source
Climate change
Burning fossil fuels is the main cause of climate change, due to the CO2 it releases into the atmosphere.
For the same amount of energy,
- coal releases about twice as much CO2 as natural gas
- oil is somewhere in between.
These numbers might be needed for physics or engineering. Greenhouse gas emissions (CO2eq) per unit of energy, for each fuel.
https://www.eia.gov/environment/emissions/co2_vol_mass.php
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
2016 Complete Report (PDF)
Using data from 2014
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2014
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2014
2016 Complete Report (PDF)
Datapoint was found on page 115, from pie chart and line graph, using data from 2014
Coal: (calculation loading)
Oil (gasoline is the most popular fuel obtained from crude oil): (calculation loading)
Natural gas, which also has fugitive emissions
Other pollution
Burning fossil fuels releases more than just CO2.
- Exhaust from cars and trucks
- Exhaust from coal power plants
These contain particles that are harmful to people and ecosystems.[ELABORATION needed]
Mitigation
- Cars and trucks already have catalytic converters that eliminate some of this pollution - but not all of it.
- For coal power plants, newer technologies could avoid most of this pollution (but still not the CO2 that causes climate change).
Scarcity
Oil reserves are expected to run out in less than a century, by most estimates.[QUANTIFICATION needed] Coal and natural gas are similar.
Fossil fuels are not considered renewable
Globally, per person, there is about 31 tonnes of oil (recoverable) somewhere in the Earth. oil.reserves(tonnes per capita)(world.population). Average production is about 1.5 kg/day per person oil.production(lbs/day per capita)(world.population). Rich countries consume a lot more, poor countries use a lot less.
Non-energy usage
Fossil fuels are also used in making plastic, most of which is disposable. Other uses include making thousands of different chemicals, but together they add up to only a small fraction of fossil fuel consumption. [QUANTIFICATION needed]