Warm Up Hydroelectric power is produced by ____. a. tides that pour through a dam barrier b. electric current that flows across a dam c. falling water that turns a turbine d. hot water that comes from deep underground The fuel for nuclear fission in nuclear reactors is ____. a. hydrogen c. carbon b. petroleum d. uranium How does nuclear fission produce energy? a. Controlled nuclear chain reaction produces heat, driving steam turbines to produce energy. b. Uncontrolled nuclear reaction produces heat, driving steam turbines to produce energy. c. Carbon atoms are bombarded by neutrons. d. Moving water turns turbines to produce electricity. Answers: 1) c. 2) d. 3) a.

Water, Air, and Land Resources Chapter 4, Section 3

The Water Planet Most of the water on the planet is salt water, not the fresh water that people need in order to live Each day, people use fresh water for drinking, cooking, bathing, and growing food Point Source Pollution – water pollution that comes from a known and specific location Nonpoint Source Pollution – water pollution that does not have a specific point of origin Runoff – water that flows over the land surface rather than seeping into the ground Fish and other aquatic life that live in polluted waters often concentrate poisons in their flesh, making them dangerous to eat

Water Pollution

Earth’s Blanket of Air Earth’s atmosphere is a blanket of nitrogen, oxygen, water vapor, and other gases The chemical composition of the atmosphere helps maintain life on Earth Certain greenhouse gases—carbon dioxide, methane, and water vapor—help maintain a warm temperature near the surface Global Warming – the increase in average temperatures of Earth and the atmosphere due in part to increased carbon dioxide levels Chlorofluorocarbons (CFCs) once used in air conditioners and plastic foam production destroy ozone, resulting in an increased incidence of health problems like cataracts and skin cancer

Primary Air Pollutants

Concept Check What is the role of ozone in the atmosphere? Ozone absorbs harmful ultraviolet radiation from the sun, thus protecting life.

Land Resources Earth’s land provides soil and forests, as well as mineral and energy resources There are an estimated 500,000 mines in the U.S., they are essential for mineral production, but tear up Earth’s surface and destroy vegetation Farmers are able to produce more food, because of increased usage of irrigation to dry areas, but this process can leave behind soil that has too great of a salt content to grow anything Clear-cutting, the removal of all trees in an area of forest, can greatly damage the land, leaving that area susceptible to soil erosion Land also serves as a disposal site, such as landfills and other waste facilities

Strip Mining

Assignment Read Ch. 4, Sect. 3 (pg. 108-112) Do Chapter 4 Assessment #1-33 (pg. 121-122) For this section look at #’s 6, 7, 12, 16, 27-29, & 32