1. End Show Slide 1 of 30 Copyright Pearson Prentice Hall Biology

2. End Show Slide 2 of 30 Copyright Pearson Prentice Hall 6-4 Charting a Course for the Future

3. End Show 6-4 Charting a Course for the Future Slide 3 of 30 Copyright Pearson Prentice Hall Ozone Depletion What are two types of global change of concern to biologists?

4. End Show 6-4 Charting a Course for the Future Slide 4 of 30 Copyright Pearson Prentice Hall 6-4 Charting a Course for the Future Researchers are gathering data to monitor and evaluate the effects of human activities on important systems in the biosphere. Two of these systems are: the ozone layer high in the atmosphere the global climate system

5. End Show 6-4 Charting a Course for the Future Slide 5 of 30 Copyright Pearson Prentice Hall Ozone Depletion Exposure to UV can: cause cancer damage eyes decrease organisms' resistance to disease damage plant leaf tissue and phytoplankton in the oceans

6. End Show 6-4 Charting a Course for the Future Slide 6 of 30 Copyright Pearson Prentice Hall Ozone Depletion Early Evidence In the 1970s, scientists discovered a hole in the ozone layer over Antarctica. After it was first discovered, the ozone hole grew larger.

7. End Show 6-4 Charting a Course for the Future Slide 7 of 30 Copyright Pearson Prentice Hall

8. End Show 6-4 Charting a Course for the Future Slide 8 of 30 Copyright Pearson Prentice Hall Ozone Depletion One Solution CFCs (chlorofluorocarbons) were once widely used: as propellants in aerosol cans as coolant in refrigerators, freezers, and air conditioners in the production of plastic foams The U.S. and other nations began reducing the use of CFCs in 1987, and eventually banned them.

9. End Show 6-4 Charting a Course for the Future Slide 9 of 30 Copyright Pearson Prentice Hall Ozone Depletion

10. End Show 6-4 Charting a Course for the Future Slide 10 of 30 Copyright Pearson Prentice Hall Global Climate Change The term used to describe the increase in the average temperature of the biosphere is global warming. One sign of global warming is melting polar ice.

11. End Show 6-4 Charting a Course for the Future Slide 11 of 30 Copyright Pearson Prentice Hall Global Climate Change

12. End Show 6-4 Charting a Course for the Future Slide 12 of 30 Copyright Pearson Prentice Hall Global Climate Change Evidence of Global Warming The geological record shows that Earth’s climate has changed repeatedly during its history.

13. End Show 6-4 Charting a Course for the Future Slide 13 of 30 Copyright Pearson Prentice Hall

14. End Show 6-4 Charting a Course for the Future Slide 14 of 30 Copyright Pearson Prentice Hall

15. End Show 6-4 Charting a Course for the Future Slide 15 of 30 Copyright Pearson Prentice Hall The Value of a Healthy Biosphere

16. End Show 6-4 Charting a Course for the Future Slide 16 of 30 Copyright Pearson Prentice Hall The Value of a Healthy Biosphere

17. End Show - or - Continue to: Click to Launch: Slide 17 of 30 Copyright Pearson Prentice Hall 6-4

18. End Show Slide 18 of 30 Copyright Pearson Prentice Hall 6-4 An increase in the average temperature of the biosphere is called a.the greenhouse effect. b.global warming. c.ozone depletion. d.climate control.

19. End Show Slide 19 of 30 Copyright Pearson Prentice Hall 6-4 The geological record indicates that Earth’s climate has a.remained essentially the same throughout history. b.been constant until humans have influenced the environment. c.changed dramatically every 150 years. d.repeatedly changed over its history.

20. End Show Slide 20 of 30 Copyright Pearson Prentice Hall 6-4 A possible effect of global warming is a.extinction of organisms in areas where they once thrived. b.an increase in global surface temperature of 20 Celsius degrees. c.a sharp decrease in the temperature of the waters off the coast of California. d.complete elimination of the protective ozone layer in the atmosphere.

21. End Show Slide 21 of 30 Copyright Pearson Prentice Hall 6-4 Depletion of Earth’s protective ozone layer results in a.a decrease in the amount of heat that reaches the surface. b.a decrease in the amount of UV radiation that reaches the surface. c.an increase in the amount of rainfall. d.an increase in the amount of UV radiation that reaches the surface.

22. End Show Slide 22 of 30 Copyright Pearson Prentice Hall 6-4 The most likely cause of ozone depletion is the a.addition of carbon dioxide to the atmosphere. b.increase in UV radiation from the sun. c.addition of chemicals developed for use in refrigeration and aerosol cans. d.increase in the amount of smog produced by automobiles.

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