Lesson 17.3 Consequences of Fossil Fuel Use The United States imports two thirds (2/3) of its crude oil. 1

Pollution, Climate Change, and Public Health Burning fossil fuels releases carbon dioxide, which contributes to global climate change. When coal and oil burn, sulfur dioxide and nitrogen oxides are released, which contribute to smog and acid rain. Oil spills, equipment ruptures, and oil in runoff pollute waterways, oceans, and coastal areas. Coal-fired power plants release mercury, which harms human health. Crude oil contains trace amounts of lead and arsenic. Did You Know? Coal-burning power plants cause 40% of mercury emissions due to human activity in the United States. 2

Gulf of Mexico Oil Well Explosions 1979: Ixtoc I exploratory oil well 50 m below surface Released 126 million gal oil; containment efforts took 9 months What didn’t work: cap, siphoning, controlled burn, “top kill” What did work: relief wells 2010: Deepwater Horizon oil well (BP) 1500 m below surface Largest U.S. offshore oil breach as of 2010- 21.2–33.5 million gal oil released during first 6 weeks (rough estimates) Hundreds of miles of coastal habitats threatened Methods tried: dome, cap, siphoning, controlled burns, “top kill,” “junk shot,” and relief wells Controlled burns attempt to contain oil pumping into the Gulf, one month after the 2010 well blow-out. 3

Damage Caused by Extracting Fuels Mining: Humans risk lives and respiratory health. Ecosystems are damaged by habitat destruction, extensive erosion, acid drainage, and heavy metal contamination down-slope of mines. Oil and gas extraction: Roads and structures built to support drilling break up habitats and harm ecosystems. The long term consequences of accidents can be uncertain or unpredictable Acid drainage from a coal mine 4

Dependence on Foreign Sources Fossil fuels are not evenly distributed over the globe, so some countries must import fuel sources. Nations that import fuel may be vulnerable to changes in fuel prices set by suppliers. Nations can import less fuel by developing domestic oil sources and renewable energy sources. 5

How Are Gas Prices Determined? Price increases generally occur when the world crude-oil market tightens and lowers inventories. Growing demand sometimes outpaces refinery capacity. Each dollar spent on gas is broken down to the following: Taxes: 12 cents Distribution and Marketing: 12 cents Refining: 14 cents Crude oil: 62 cents http://gaspricesexplained.org/?gclid=CNOE96Xm37ICFQuk4Aod_lUAEA

OPEC (Organization of the Petroleum Exporting Countries) determines the price of a barrel of oil. A barrel price is determined by the type of oil: lighter oil is cheaper and heavy oil is expensive. Why??? Because it costs more to refine heavy oil There is a very low supply of lighter oil. Also, it takes more energy to remove heavy oil from the ground. Growing demand in countries like India, Brazil, and China, which tripled the number of cars on the road in the last five years, will drive prices even higher over the long term.

Energy Conservation Defined as the practice of reducing energy use to make fossil fuels last and to prevent environmental damage. Divided into (2) categories: Transportation: Gas-efficient cars and higher gas prices could help conserve energy in the U.S Personal choices: Individuals can save energy by turning off lights, taking public transit, insulating their homes, and buying energy-efficient appliances. Did You Know? Transportation accounts for 2/3 of U.S. oil consumption. 11

Lesson 17.4 Nuclear Power Scientists estimate that nuclear power helps us avoid emitting 600 million metric tons of carbon each year worldwide. 12

Nuclear Power Facts PRO----Doesn’t pollute the air CON---- What do you do with the radioactive waste (disposal) and major nuclear power plant accidents release large amounts of radioactive particles into the air and ground Only 20% of the US electricity comes from nuclear power The reaction that drives the release of nuclear energy in power plants is called nuclear fission.

Nuclear Fission Splits an atomic nucleus into two smaller nuclei Lesson 17.4 Nuclear Power Nuclear Fission Splits an atomic nucleus into two smaller nuclei Releases neutrons and large amounts of energy. If enough unstable nuclei are present, a nuclear chain reaction can occur. 14

Generating Electricity Using Nuclear Energy Lesson 17.4 Nuclear Power Generating Electricity Using Nuclear Energy 15

Nuclear Fission takes place Nuclear Fission takes place. The fission generates lots of heat which is transferred to the surrounding water. Steam is produced. The steam flows to the turbine through pipes. Electricity is generated. The steam causes the turbine to rotate which then makes the generator move and produce electricity. Water is cooled. Steam flows to a condenser which cools the water vapor and converts it back into liquid water.

Benefits and Costs of Nuclear Power Lesson 17.4 Nuclear Power Benefits and Costs of Nuclear Power Benefits Costs No air pollution Expensive to build and maintain Requires little uranium fuel and little mining Catastrophic accidents are possible. Under normal conditions, nuclear power plants are safer for workers than coal-burning power plants. Nuclear waste must be stored for thousands of years. Chernobyl 17

Lesson 17.4 Nuclear Power Nuclear Waste Waste is currently held at power plants as a stopgap, but a long-term storage location is needed. Long-term storage sites must be distant from population centers, protected from sabotage, have a deep water table, and be geologically stable. Yucca Mountain, Nevada, was chosen by the U.S. government in the 1980s, and a storage site was constructed there. But, as of 2010, the Yucca Mountain project is no longer under development. Yucca Mountain storage site 18

Nuclear Fusion: The Future? These reactions generate the energy released by the sun. Could produce much more energy per amount of fuel than nuclear fission can. However, these reactions require large temperatures to occur (millions of degrees of Celsius). Research also shows that in a lab situation, fusion reactions require more energy than they produce. Long way off….

Nuclear Fusion Joining two atomic nuclei to form one nucleus Lesson 17.4 Nuclear Power Nuclear Fusion Joining two atomic nuclei to form one nucleus Releases much more energy than fission reactions Currently impractical because very high temperatures are needed, but scientists continue exploring fusion for our future energy needs 20