1. Climate Control and Ozone Depletion Chapter 19

2. An Enormous Cloud of Air Pollutants and Ash from Iceland volcano (April 2010) This dust cloud closed Airports in Europe for almost one week.

3. Coal Power Plant emitting green house gas

4. 19-1 How Might the Earth’s Temperature and Climate Change in the Future?  Concept 19-1 The overwhelming scientific consensus is that the earth’s atmosphere is warming rapidly, mostly because of human activities, and that this will lead to significant climate change during this century.

5. How Do We Know What Temperatures Were in the Past?  Scientists analyze tiny air bubbles trapped in ice cores learn about past: troposphere composition. temperature trends. greenhouse gas concentrations. solar, snowfall, and forest fire activity.

6. Estimated Changes in the Average Global Temperature of the Atmosphere Fig19-2

7. Carbon Dioxide at highest levels  In 2005, an ice core showed that CO 2 levels in the troposphere are the highest they have been in 650,000 years.

8. The Natural Greenhouse Effect  Four major factors shape the earth’s climate: The sun. Greenhouse effect that warms the earth’s lower troposphere and surface because of the presence of greenhouse gases. Oceans store CO 2 and heat, evaporate and receive water, move stored heat to other parts of the world. Natural cooling process through water vapor in the troposphere (heat rises).

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

10. Keeling Curve

11. IPCC greenhouse gases by source

12. Carbon Dioxide Trends (IPCC)

13. Animation: Greenhouse effect

14. The Atmosphere Is Warming Mostly Because of Human Activities  Intergovernmental Panel on Climate Change (IPCC) 90–99% likely that lower atmosphere is warming 1906–2005: Ave. temp increased about 0.74˚C 1970–2005: Annual greenhouse emissions up 70% Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth Melting of glaciers and floating sea ice Prolonged droughts: increasing Last 100 years: sea levels rose 10–20 cm Warmer temperatures in Alaska, Russia, and the Arctic are melting permafrost releasing more CO 2 and CH 4 into the troposphere.

15. Melting of Alaska’s Muir Glacier between 1948 and 2004

16. The Big Melt: Some of the Floating Sea Ice in the Arctic Sea

17. The Scientific Consensus about Future Climate Change  There is strong evidence that human activities will play an important role in changing the earth’s climate during this century. Coupled General Circulation Models (CGCMs) couple, or combine, the effects of the atmosphere and the oceans on climate.

18. Fig. 19-A, p. 502 Sun Troposphere Cooling from increase Aerosols Greenhouse gases Warming from decrease CO 2 removal by plants and soil organisms CO 2 emissions from land clearing, fires, and decay Heat and CO 2 removal Heat and CO 2 emissions Ice and snow cover Shallow ocean Land and soil biota Long-term storage Natural and human emissions Deep ocean

19. CGC Models sources NASA

20. IPCC Climate Change Model

21. Comparison of Measured Temperature from 1860–2007 and Projected Changes Fig 19-b

23. Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report 2007 Click for IPCC web page Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread Melting of snow and ice and rising global average sea level (Figure SPM.1). {1.1} Most of the observed increase in global average Temperatures since the mid-20th century is very likely (p =.90) due to the observed increase in anthropogenic GHG concentrations. (Figure SPM.4). {2.4}

24. IPCC Treatment of Uncertainty Where uncertainty is assessed more quantitatively using expert judgment of the correctness of underlying data, models or analyses, then the following scale of confidence levels is used to express the assessed chance of a finding being correct: very high confidence at least 9 out of 10; high confidence about 8 out of 10; medium confidence about 5 out of 10. Where uncertainty in specific outcomes is assessed using expert judgment and statistical analysis of a body of evidence (e.g. observations or model results), then the following likelihood ranges are used to express the assessed probability of occurrence: virtually certain >99%; extremely likely >95%; very likely >90%; likely >66%;.

26. IPCC Emissions and Equilibrium Temperatures

27. IPCC Temperature projections

28. Is a Hotter Sun the Culprit?  Since 1975 Troposphere has warmed Stratosphere has cooled  This is not what a hotter sun would do

29. Changing Ocean Currents  Global warming could alter ocean currents and cause both excessive warming and severe cooling.

30. Ocean Acidification Click for Ocean Acidification Network Click for NRDC Acid Test

31. FACTORS AFFECTING THE EARTH’S TEMPERATURE  Some factors can amplify (positive feedback) and some can dampen (negative feedback) projected global warming.  There is uncertainty about how much CO 2 and heat the oceans can remove from the troposphere and how long the heat and CO 2 might remain there.

32. There Is Uncertainty about the Effects of Cloud Cover on Global Warming  Warmer temperatures create more clouds Thick, light-colored low altitude clouds: decrease surface temperature Thin, cirrus clouds at high altitudes: increase surface temperature

33. Outdoor Air Pollution Can Temporarily Slow Global Warming  Aerosol and soot pollutants Will not enhance or counteract projected global warming Fall back to the earth or are washed out of the lower atmosphere Reduction: especially in developed countries

34. DEALING WITH GLOBAL WARMING  Climate change is such a difficult problem to deal with because: The problem is global. The effects will last a long time. The problem is a long-term political issue. The harmful and beneficial impacts of climate change are not spread evenly. Many actions that might reduce the threat are controversial because they can impact economies and lifestyles.

35. 19-2 What Are Some Possible Effects of a Warmer Atmosphere?  Concept 19-2 The projected rapid change in the atmosphere's temperature during this century is very likely to increase drought and flooding, shift areas where food can be grown, raise sea levels, result in intense heat waves, and cause the premature extinction of many species.

37. IPCC Projected Regional Impacts

38. IPCC Impacts Very likely = 90% probable

39. Enhanced Global Warming Could Have Severe Consequences  Tipping point and irreversible climate change  Worst-case scenarios Ecosystems collapsing Low-lying cities flooded Wildfires in forests Prolonged droughts: grasslands become dust bowls More destructive storms Glaciers shrinking; rivers drying up

40. Projected Effects of Global Warming and the Resulting Changes in Global Climate Fig 19-7

41. Severe Drought Is Increasing: The Browning of the Earth  Accelerate global warming, lead to more drought  Biodiversity will decrease  Net Primary Productivity (NPP) will decrease  Dry climate ecosystems will increase

42. Ice and Snow Are Melting  Europe’s Alps Glaciers are disappearing  South America Glaciers are disappearing  Greenland Warmer temperatures

43. Areas of Glacial Ice Melting in Greenland during Summer 1982–2007 Increased Fig 19-c

44. Sea Levels Are Rising  Projected irreversible effect Degradation and loss of 1/3 of coastal estuaries, wetlands, and coral reefs Disruption of coastal fisheries Flooding of Low-lying barrier islands and coastal areas Agricultural lowlands and deltas Contamination of freshwater aquifers Submergence of low-lying islands in the Pacific and Indian Oceans and the Caribbean

45. Areas of Florida, U.S., to Flood If Average Sea Level Rises by One Meter Fig19-8

46. Low-Lying Island Nation: Maldives in the Indian Ocean

47. Permafrost Is Likely to Melt: Another Dangerous Scenario  Carbon present as CH 4 in permafrost soils and lake bottoms  2004: Arctic Climate Impact Assessment 10–20% of the permafrost might melt this century  Effect on global warming – ice reflects heat, land absorbs heat.

48. Projected Decline in Arctic Tundra in Portions of Russia from 2004 to 2100 Fig 19-10

49. Global Warming Is a Major Threat to Biodiversity  Most susceptible ecosystems Coral reefs Polar seas Coastal wetland High-elevation mountaintops Alpine and arctic tundra

50. Effects on Biodiversity: Winners and Losers  Possible effects of global warming on the geographic range of beech trees based on ecological evidence and computer models.

51. Changes in Average Ocean Temperatures, Relative to Coral Bleaching Threshold Fig 19-11

52. Exploding Populations of Mountain Pine Beetles in British Columbia, Canada

53. Climate Change Will Shift Areas Where Crops Can Be Grown  Regions of farming may shift Decrease in tropical and subtropical areas Increase in northern latitudes Less productivity; soil not as fertile  Genetically engineered crops more tolerant to drought

54. Climate Change Will Threaten the Health of Many People  Deaths from heat waves will increase  Deaths from cold weather will decrease  Higher temperatures can cause Increased flooding Increase in some forms of air pollution, more O 3 More insects, microbes, toxic molds, and fungi

55. 19-3 What Can We Do to Slow Climate Change? (1)  Concept 19-3A To slow the rate of global warming and climate change, we can increase energy efficiency, sharply reduce greenhouse gas emissions, rely more on renewable energy resources, and slow population growth.

56. DEALING WITH GLOBAL WARMING  Climate change is such a difficult problem to deal with because: The problem is global. The effects will last a long time. The problem is a long-term political issue. The harmful and beneficial impacts of climate change are not spread evenly. Many actions that might reduce the threat are controversial because they can impact economies and lifestyles.

57. 19-3 What Can We Do to Slow Climate Change? (2)  Concept 19-3B Governments can subsidize energy efficiency and renewable energy use, tax greenhouse gas emissions, set up cap-and- trade emission reduction systems, and help to slow population growth.

58. DEALING WITH GLOBAL WARMING  Two ways to deal with global warming: Mitigation that reduces greenhouse gas emissions. Adaptation, where we recognize that some warming is unavoidable and devise strategies to reduce its harmful effects.

59. DEALING WITH GLOBAL WARMING  Governments can tax greenhouse gas emissions and energy use, increase subsidies and tax breaks for saving energy, and decrease subsidies and tax breaks for fossil fuels.  A cash program to slow and adapt to global warming now is very likely to cost less than waiting and having to deal with its harmful effects later.

60. Avoiding Catastrophe: We Can Reduce the Threat of Climate Change  Input or prevention strategies  Improve energy efficiency to reduce fossil fuel use  Stop cutting down tropical forests  Output strategy Capture and store CO 2

61. IPCC Climate Change Model

62. Fig. 19-13, p. 515 SOLUTIONS Global Warming Prevention Cleanup Cut fossil fuel use (especially coal) Remove CO 2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO 2 by planting trees Improve energy efficiency Sequester CO 2 deep underground (with no leaks allowed) Shift to renewable energy resources Transfer energy efficiency and renewable energy technologies to developing countries Sequester CO 2 in soil by using no-till cultivation and taking cropland out of production Reduce deforestation Sequester CO 2 in the deep ocean (with no leaks allowed) Use more sustainable agriculture and forestry Repair leaky natural gas pipelines and facilities Limit urban sprawl Reduce poverty Use animal feeds that reduce CH 4 emissions from cows (belching) Slow population growth

63. International Climate Negotiations: The Kyoto Protocol –Treaty on global warming which first phase went into effect January, 2005 with 189 countries participating. –It requires 38 participating developed countries to cut their emissions of CO 2, CH 4, and N 2 O to 5.2% below their 1990 levels by 2012. –Developing countries were excluded. The U.S. did not sign, but California and Maine are participating. U.S. did not sign because developing countries such as China, India and Brazil were excluded.

64. Fifteen Ways to Cut CO 2 Emissions

65. Fig. 19-14, p. 515 Stepped Art

66. Some Output Methods for Removing CO 2 from the Atmosphere and Storing It Fig19-15

67. Case Study: Is Capturing and Storing CO 2 the Answer?  Problems with carbon capture and storage cont… Promotes the continued use of coal (world’s dirtiest fuel) Effect of government subsidies and tax breaks Stored CO 2 would have to remain sealed forever: no leaking. This is book’s opinion. Flint does not agree

68. Some Governments Are Leading the Way  Costa Rica: goal to be carbon neutral by 2030  Norway: aims to be carbon neutral by 2050  China and India must change energy habits  U.S. cities and states taking initiatives to reduce carbon emissions

69. What Can You Do? Reducing CO 2 Emissions Fig 19-16

70. We Can Prepare for the Harmful Effects of Climate Change?  Genetically engineer crops more tolerant to drought  Stockpile 1–5 years of key foods  Waste less water  Connect wildlife reserves with corridors

71. Ways to Prepare for the Possible Long- Term Harmful Effects of Climate Change Fig19-17

72. 19-4 How Have We Depleted O 3 in the Stratosphere and What Can We Do?  Concept 19-4A Widespread use of certain chemicals has reduced ozone levels in the stratosphere, which allows for more harmful ultraviolet radiation to reach the earth’s surface.  Concept 19-4B To reverse ozone depletion, we must stop producing ozone-depleting chemicals and adhere to the international treaties that ban such chemicals.

73. Fig. 19-18, p. 523 300 290 280 270 Mean Total Ozone Level (Dobson units) 1970 1980199020002010 260 Year

74. Natural Capital Degradation: Massive Ozone Thinning over Antarctica in 2007 Fig 19-19

75. Science Focus: Rowland and Moline—A Scientific Story of Courage and Persistence  Research CFCs are persistent in the atmosphere Rise into the stratosphere over 11-20 years Break down under high-energy UV radiation Halogens produced accelerate the breakdown of O 3 to O 2 Each CFC molecule can last 65-385 years  1988: Dupont stopped producing CFCs

76. Summary of CFCs and Other Chlorine- Containing Compounds that Destroy Ozone Fig19-d

77. Natural Capital Degradation: Effects of Ozone Depletion Fig 19-20

78. Structure of the Human Skin and the Relationship between UV and Skin Cancer Fig 19-e

79. Thin layer of dead cells Squamous cells Epidermis Basal layer Sweat gland Melanocyte cells Dermis Blood vessels Basal cell Hair This long-wavelength (low-energy) form of UV radiation causes aging of the skin, tanning, and sometimes sunburn. It penetrates deeply and may contribute to skin cancer. This shorter-wavelength (high-energy) form of UV radiation causes sunburn, premature aging, and wrinkling. It is largely responsible for basal and squamous cell carcinomas and plays a role in malignant melanoma. Ultraviolet A Ultraviolet B Fig. 19-E, p. 526 Stepped Art Basal Cell Carcinoma Melanoma Squamous Cell Carcinoma

80. Human Health Worse sunburn More eye cataracts More skin cancers Immune system suppression Food and Forests Reduced yields for some crops Reduced seafood supplies from reduced phytoplankton Decreased forest productivity for UV-sensitive tree species Wildlife Increased eye cataracts in some species Decreased population of aquatic species sensitive to UV radiation Reduced population of surface phytoplankton Disrupted aquatic food webs from reduced phytoplankton Air Pollution and Materials Increased acid deposition Increased photochemical smog Degradation of outdoor paints and plastics Global Warming Accelerated warming because of decreased ocean uptake of CO2 from atmosphere by phytoplankton and CFCs acting as greenhouse gases Effects of Ozone Depletion Natural Capital Degradation Fig 19-20

81. What Can You Do? Reducing Exposure to UV Radiation Fig 19-f

82. We Can Reverse Stratospheric Ozone Depletion  Stop producing all ozone-depleting chemicals  60–100 years of recovery of the O 3 layer  1987: Montreal Protocol  1992: Copenhagen Protocol  Ozone protocols: prevention is the key

83. Animation: How CFCs destroy ozone