Environmental Science
Chapter 17 Section 1

Fossil Fuels
• The remains of ancient organisms that changed into coal, oil, or natural gas.
• Fuels we use to run cars, ships, planes, and factories and to produce electricity.
• Natural resources.
• Two main problems:
• Supply is limited.
• Obtaining and using them causes environmental problems.

Fuels for Different Uses
• Fuels are used for five main purposes:
• Cooking
• Transportation
• Manufacturing
• Heating and cooling buildings
• Generating electricity to run machines and appliances
• Sustainability depends on the fuel’s energy content, cost, availability, and safety, and the byproducts of the fuel’s use.

Fuels for Different Uses
• Examples:
• Coal
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•
Readily available and inexpensive
Used to heat homes
• Airplane fuel
•
•
More energy per mass than coal
Expensive
• Wood
•
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Low energy per mass comparatively
Generally inexpensive

Electricity – Power on Demand
• Energy in fuels is often converted into electrical energy in order to power machines.
• Can be transported quickly across great distances.
• Generated in power plants.
• Disadvantages:
• Difficult to store.
• Other energy sources have to be used to generate it.

Electricity – Power on Demand
• How is Electricity Generated?
•
• Electric generator – machine that converts mechanical energy into electrical energy.
Turbine – a wheel that changes the force of a moving gas or liquid into energy that can do work.
• Most power plants boil water to produce steam that turns the turbine.
• Turbine spins a generator to produce electricity.

Electricity – Power on Demand

Energy Use
• World Patterns
• People in developed societies use much more energy that people in developing countries.
• Energy use in some developing countries is growing rapidly.

Energy Use
• Energy Use in the United States
• The United States uses more energy per person than any other country in the world except for Canada and the United Arab
Emirates.
• More than 25% is used to transport goods and people. Other countries have better mass transportation systems.
• Fuel is lower cost in the U.S. than other places, which leads to greater usage.

How Fossil-Fuel Deposits Form
• Coal Formation
• Coal forms from the remains of plants that lived in swamps hundreds of millions of years ago.
• Layers of sediment added as the sea level rose and fell and compressed the remains, causing coal to form.

How Fossil-Fuel Deposits Form
• Oil and Natural Gas Formation
• Result from the decay of tiny marine organisms that accumulated on the bottom of the ocean millions of years ago.
• Buried by sediments, then heated until they became complex energy-rich carbon-based molecules.
• Over time, molecules migrated into the porous rocks that now contain them.
• Much is found in Alaska, Texas, California, and the Gulf of Mexico.

How Fossil-Fuel Deposits Form

Coal
• Coal Mining and the Environment
• Environmental effects of mining coal vary.
• Underground mines can have a minimal effect on the surface.
• Sometimes, it is necessary to disturb the surface of the land to reach the deposit.
• Toxic chemicals can leach into nearby streams.

Coal
• Air Pollution
• Bituminous coal (high-grade) produces more heat and less pollution than lignite (low-grade).
• Sulfur is a major source of coal pollution.
• Results in acid rain.

Petroleum
• Petroleum – oil that is pumped from the ground – crude oil.
• Petroleum product – anything that is made from crude oil.
• Fuels
• Chemicals
• Plastics

Petroleum
• Locating Oil Deposits
•
•
Oil is found in and around major geologic features, such as folds, faults, and salt domes.
• Impermeable layers of rock prevent the oil from escaping.
Most of the world’s oil reserves are in the Middle East.
• Large deposits also exist in the U.S., Venezuela, the North Sea,
Siberia, and Nigeria.
• Oil is removed from a well and then transported to a refinery to be converted into fuels and other petroleum products.

Petroleum
• The Environmental Effects of Using Oil
• When petroleum fuels are burned, they release pollutants.
• Emissions regulations and technology have helped to reduce air pollutants.
• Oil spills are dramatic, but cars leaking oil causes more pollution every day.

Petroleum
• Natural Gas
• About 20% of the world’s nonrenewable energy.
• Many oil wells recover natural gas.
• Fewer pollutants than other fuels.

Fossil Fuels and the Future
• Predicting Oil Production
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Oil production is increasing, but more slowly than in the past.
Oil reserves – oil deposits that can be extracted profitably at current prices using current technology.
• All predictions of future oil production are guided by an important principle:
• The relative cost of obtaining fuels influences the amount of fossil fuels that we extract from the Earth.
• i.e. as supply decreases, we may rely on other sources.

Fossil Fuels and the Future
• Future Oil Reserves
• No large oil reserves have been discovered recently.
• Deep-ocean may be tapped in the future.
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Many issues.
Think of the BP oil spill in the Gulf…