1. Environmental Science: Toward a Sustainable Future Richard T. Wright The Atmosphere: Climate, Climate Change, and Ozone Depletion PPT by Clark E. Adams Chapter 20

2. El Niño: What Happened? Jet streams shifted from normal course Cause unknown AprilMay June

3. The El Niño Effects: Fig. 20-1 Landslides on the California coast Mildest hurricane season in many years Rain five times normal in an East Africa drought region Record crop harvests in India, Australia, and Argentina

4. La Niña: What Happened? Easterly trade winds reestablished with greater intensity Upwelling of colder water from ocean depths Jet streams are weakened Global patterns in moisture and evaporation return to “normal”

5. Atmospheric Structure

7. Weather: Solar Energy Balance Most solar energy absorbed by atmosphere, oceans, and land

8. Weather: Convection Cell

9. Tornadoes Cold low-pressure air mass collides with a warm high- pressure air mass http://www.photolib.noaa.gov/nssl/nssl0065.htm

10. Fujita Scale Measures the Intensity of Tornadoes F-0: 40–72 mph, chimney damage, tree branches broken F-1: 73–112 mph, mobile homes pushed off foundations or overturned F-2: 113–157 mph, considerable damage, mobile homes demolished, trees uprooted

11. Fujita Scale Measures the Intensity of Tornadoes F-3: 158–205 mph, roofs and walls torn down, trains overturned, cars thrown F-4: 207–260 mph, well-constructed walls leveled F-5: 261–318 mph, homes lifted off foundation and carried considerable distances, autos thrown as far as 100 meters

12. Climates in the Past

13. Ocean and Atmosphere Covers 75% of the Earth’s surface Major source of water to hydrologic cycle Major source of heat to atmosphere Stores and conveys heat

14. The Ocean Conveyor System

15. The Earth as a Greenhouse

16. Factors Affecting Global Temperatures Cloud cover: cooling Changes in Sun’s intensity: cooling or warming Volcanic activity: cooling Sulfate aerosols: cooling

17. Atmospheric CO 2 Concentrations

19. Global Surface Temperatures

20. Global Carbon Cycle

21. Impacts of Global Warming Melting of polar ice caps Flooding of coastal areas Massive migrations of people inland

22. Evidences of Climatic Change 17 of the hottest years on record have occurred since 1980 (Fig. 20-5) Wide-scale recession of glaciers Sea level rising Predicted mean global temperature change by 2100 is between 1.5 and 4.5 o C

23. Responses to Climate Change Response 1: mitigation = reduce CO 2 emissions Response 2: adaptation = accepting and learning to live with the consequences of climate change

24. Framework Convention on Climate Change (FCC) Relied on voluntary approach to reduce CO 2 emissions Developing countries continue toward developed nation status using fossil fuels

25. Framework Convention on Climate Change (FCC) To achieve a 7% reduction by 2010 requires a 25% reduction of present use By 2010 CO 2 emissions will have increased by 30%

26. Framework Convention on Climate Change (FCC) Bottom line: need 60% reduction (144 ppm) in CO 2 emission worldwide NOW to stabilize greenhouse gas concentrations at today’s levels

27. Depletion of Ozone Layer Radiation and importance of the shield Formation and breakdown of the shield Coming to grips with ozone depletion

28. Good Ozone! Bad Ozone!

29. Electromagnetic Spectrum

30. Formation of the Ozone Shield Reaction #1: UV light + O 2 O + O Reaction #2: Free O + O 2 O3O3 Reaction #3: Free O + O 3 O 2 + O 2 Reaction #4: UV light + O 3 O + O 2

31. Breakdown of Ozone Shield Reaction #5: CFCl 3 + UV Cl + CFCl 2 Reaction #6: Cl + O 3 ClO + O 2 Reaction #7: ClO + ClO 2 Cl + O 2 Which reaction releases Cl from CFCs? Which reaction generates more Cl? Chlorine is a catalyst that destroys the production of ________?

33. Montreal Protocol 1987 – scale back CFC production by 50% by 2000

34. Coming to Grips with Ozone Depletion: Montreal Protocol 1990 – amendment to completely phase out ozone-destroying chemicals by 2000 1992 – amendment to completely phase out ozone-destroying chemicals by 1996 Why the rush?

35. Ozone Hole: 11 million sq.mi.

36. The Clean Air Act of 1990: Title IV Restricts production, use, emissions, and disposal of ozone-depleting chemicals Regulates the servicing of refrigeration and air-conditioning units “Protecting Stratospheric Ozone”

37. Greenhouse GasesOzone Where Type of Light Chemicals What’s the big deal? Major Law How do we fix it?

38. End of Chapter 20