1. Ch. 19 Climate Disruption & Ozone Depletion

2. How Might the Earth’s Temperature & Climate Change in the Future? * Considerable scientific evidence indicates that the earth’s atmosphere is warming, because of a combination of natural effects and human activities, and that this warming is likely to lead to significant climate disruption during this century.

3. Weather & Climate Are Not The Same Weather Short-term changes in atmospheric variables in given area over a period of hours/days Temperature Precipitation Wind Barometric Pressure Climate Average weather conditions of a particular area over long period of time (decades, centuries, thousands of years) Temperature Precipitation Minimum Period = 3 decades

4. Climate Change is NOT New Over the past 4.7 billion years the climate has been altered by –Volcanic emissions

5. Climate Change is NOT New Over the past 4.7 billion years the climate has been altered by –Changes in solar input

6. Climate Change is NOT New Over the past 4.7 billion years the climate has been altered by –Movement of the continents

7. Climate Change is NOT New Over the past 4.7 billion years the climate has been altered by –Impacts by meteors

8. Climate Change is NOT New Over the past 4.7 billion years the climate has been altered by –Changing global air and ocean circulation

9. Climate Change is NOT New Over the past 900,000 years –Glacial and interglacial periods

10. Climate Change is NOT New Over the past 10,000 years –Interglacial period Over the past 1,000 years –Temperature stable Over the past 100 years –Temperature changes; methods of determination

11. Estimated Changes in the Average Global Temperature of the Atmosphere Fig. 19-2, p. 494

12. Fig. 19-2a, p. 494 17 Average surface temperature (°C) 800700 600 500 400 300 200 100 Thousands of years ago 16 14 9 10 11 12 13 15 900Present

13. Fig. 19-2b, p. 494 15.0 Average surface temperature (°C) 18801900 1920 1940 1960 1980 2000 2020 Year 14.8 14.6 14.4 14.2 14.0 13.8 13.6 *

14. Fig. 19-2c, p. 494 TEMPERATURE CHANGE (over past 22,000 years) 2 1 Agriculture established End of last ice age -2 Average temperature over past 10,000 years = 15°C (59°F) -4 Temperature change (°C) 20,0002,000200100Now Years ago 0 -3 -5 10,0001,000

15. Fig. 19-2d, p. 494 0.5 0.0 -0.5 Temperature change (°C) 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 Year

16. How do we know past changes in temperature? Radioisotopes in rocks & fossils Plankton & radioisotopes in ocean sediments Pollen from lake bottoms Ice cores from ancient glaciers Tree rings Radioisotopes in corals Historic record – since 1861 Temperature measurements

17. Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers* Fig. 19-3, p. 495

18. The Natural Greenhouse Effect (tropospheric heating effect)*

19. Greenhouse Gases (1% of earth’s lower atmosphere) Water Vapor (H 2 O) Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O)

20. How does the greenhouse effect work? 1.Heat radiates into atm. from earth 2.Causes molecules of gases to vibrate 3.Molecules release infrared radiation (even longer wavelength) 4.Radiation interacts w/ molecules 5. kinetic energy - warms lower atm. & earth’s surface 6.Overtime affects earth’s climate.

21. Without the greenhouse effect, earth would be frigid and uninhabitable

22. So, what’s the problem? *

23. Global Climate Change AKA Global Warming Caused by ENHANCED Greenhouse Effect

24. CO 2, NO X, CFCs, CH 4 These gases absorb infrared (IR) radiation in upper atmosphere (stratosphere) and trap heat in lower atmosphere (troposophere) ABOVE “normal” levels, increasing greenhouse effect hence the name Greenhouse Gases

25. Global Climate Change Caused by CO 2 Concentration in atmosphere from: –Burning fossil fuels –Land conversion (loss of plant material that absorb CO 2 ) 2010: 389 ppm 2050: 560 ppm 2100: 1,390 ppm 450 ppm as tipping point

26. other gases in atmosphere such as: –NO x, CFCs, CH 4 Global Climate Change Caused by

27. Human Activities Emit Large Quantities of Greenhouse Gases Since Industrial Revolution –CO 2, CH 4, and N 2 O emissions higher –Main sources: agriculture, deforestation, and burning of fossil fuels Correlation of rising CO 2 and CH 4 with rising global temperatures

28. Atmospheric Levels of CO 2 and CH 4, Global Temperatures, and Sea Levels Fig. 19-4, p. 496

29. Correlation of CO 2 and Temperature Fig. 19-5, p. 497

30. Greenhouse Gases from Human Activities Greenhouse GasAverage Time in the Troposphere Relative Warming Potential (CO 2 ) Carbon Dioxide50-120 years1 Methane12-18 years23 Nitrous Oxide114-120 years296 Chloroflorocarbons11-20 years900-8,300 Hydrochloro- flurocarbons 9-390 years470-2,000 Hydroflurocarbons15-390 years130-12,700 Halons65 years5,500 Carbon Tetrachloride42 years1,400

31. Intergovernmental Panel on Climate Change (IPCC) Established 1988 Document past and project future climate changes Includes more than 2,500 scientists from more than 130 countries

32. IPCC Major Findings see page 497 –90–99% likely that lower atmosphere is warming Especially since 1960 Mostly from human-caused increases in greenhouse gases Earth’s climate is now changing from increased greenhouse gases –Increased greenhouse gas concentrations will likely trigger significant climate disruption this century –Ecological, economic, and social disruptions

33. Climate Change & Human Activities Increased Use of Fossil Fuels (CO 2, CH 4 ) Deforestation (CO 2, N 2 O) Cultivation of Rice Patties (N 2 ) Global Warming = ENHANCED Greenhouse Effect –Melting icecaps & glaciers –Coral reef bleaching –Other

34. Global Warming Effects * 1.Melting ice caps & glaciers a.Evidence = retreating glaciers, shrinking ice sheets

35. Global Warming Effects 2. Sea Level Rise a.FROM added volumes of freshwater BUT also from thermal expansions b.Coastline threats (resulting in pop. displacement – LA, NYC, Miami)

36. Areas of Florida to Flood If Average Sea Level Rises by One Meter Fig. 19-11, p. 507

37. Global Warming Effects 3. Permafrost Decline in tundra regions (microclimate changes)

38. Global Warming Effects 3. Permafrost Decline in tundra regions (microclimate changes) –Methane, a greenhouse gas, will be released into the atmosphere Arctic permafrost contains 50-60x the amount of carbon dioxide emitted annually from burning fossil fuels Methane in permafrost on Arctic Sea floor

39. Global Warming Effects 4. In precipitation patterns a.Frequent drought, rain, snow, flooding b.Increased frequency and intensity of storms over warmed surfaces (Sandy/Katrina)

40. Global Warming Effects 5. In biology a.Migration patterns disrupted b.Food web disturbances c.Habitat fragmentation (reduced realized niche)

41. Global Warming Effects 6. Human Health a.Health related illnesses b.Disease spread by organisms now with extended ranges (mosquitos & malaria)

42. Global Warming Effects 7. Agriculture a.Sea level rise will impact farmland by flooding coastal regions b.Severe Drought c.Shift in farming regions

43. Factors Contributing to Global Warming Biggest Factor = CO 2 Emissions

44. World’s Larges Emitters of CO 2 Largest emitters, 2009 1. China 2. United States 3. European Union (27 countries) 4. Indonesia 5. Russia 6. Japan 7. India

45. World’s Larges Emitters of CO 2

46. Factors Contributing to Global Warming Waste Heat –Second Law of Thermodynamics!! –Burning Fossil Fuels = CO2 emissions + Waste Heat

47. Factors Contributing to Global Warming Solubility of CO 2 in Ocean Water Warmer oceans –Last century: 0.32-0.67C°increase –Absorb less CO 2 and hasten atmospheric warming –CO 2 levels increasing acidity –Affect phytoplankton and other organisms