1. Climate Control and Ozone Depletion Chapter 19

2. 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.

3. Global Warming and Global Cooling Are Not New  Over the past 4.7 billion years the climate has been altered by Volcanic emissions Changes in solar input Movement of the continents Impacts by meteors  Over the past 900,000 years Glacial and interglacial periods

4. Global Warming and Global Cooling Are 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

5. Paleoclimatology  Studying past climates using imprints made during past climates (proxies) analysis of radioisotopes in rocks/fossils plankton & radioisotopes in ocean sediments ice cores from glaciers (tiny air bubbles) pollen from bottom of lakes/bogs tree rings minerals in different layers of bat dung

6.  http://channel.nationalgeographic.com/videos/ic e-age-cycles/

7. Earth’s Climate Cycles  Earth’s climate has changed throughout its history Ice ages/ glacial maximums – cold periods Warm period/ glacial minimum – warm climate

8. http://jan.ucc.nau.edu/~rcb7/nam.html

9. Estimated Changes in the Average Global Temperature of the Atmosphere

10. Science: Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers

11. Our Climate, Lives, and Economies Depend on the Natural Greenhouse Effect  Without the natural greenhouse effect Cold, uninhabitable earth

12. Greenhouse Gases  The heat from the sun is absorbed by greenhouse gases  Greenhouse gas – gas that absorbs and radiates heat  Greenhouse gases: water vapor (H 2 O) carbon dioxide (CO 2 ) chlorofluorocarbons (CFCs) Methane (CH 4 ) nitrous oxide (N 2 O)

13. Shortwave vs. Longwave radiation

15. Greenhouse Effect Video  https://www.youtube.com/watch?v=sTvqIijqvTg  https://www.youtube.com/watch?v=BPJJM_hCFj 0

16. Human Activities Emit Large Quantities of Greenhouses Gases (1)  Since the 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

18. Atmospheric Levels of CO 2 and CH 4, Global Temperatures, and Sea Levels

20. The Atmosphere Is Warming Mostly Because of Human Activities (1)  Intergovernmental Panel on Climate Change (IPCC) 90–99% likely that lower atmosphere is warming and humans are responsible 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

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

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

23. Al Gore – Inconvenient Truth Clips  https://www.youtube.com/watch?v=Jxi-OlkmxZ4 https://www.youtube.com/watch?v=Jxi-OlkmxZ4  https://www.ted.com/talks/al_gore_warns_on_lat est_climate_trends?language=en

24. Self Quiz  What is the greenhouse effect?  What is climate change?  What is paleoclimatology?  How do we know about Earth’s climate cycles?  How might humans be altering these climate cycles?

25. Simplified Model of Some Major Processes That Interact to Determine Climate

26. 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

27. What Is the Scientific Consensus about Future Temperature Change?  Mathematical models used for predictions  Global warming: rapid rate  Human factors are the major cause of temperature rise since 1950  Human factors will become a greater risk factor

28. Comparison of Measured Temperature from 1860–2007 and Projected Changes

29. Can the Oceans Save Us?  The oceans are our largest carbon sink  Warmer oceans CO 2 levels increasing acidity Ocean acidification Effect on atmospheric levels of CO 2 Effect on coral reefs

31. Outdoor Air Pollution Can Temporarily Slow Climate Change  Aerosol and soot pollutants  Naturally occurring and human produced  Atmospheric aerosols – microscopic droplets/ solid particles suspended in the atmosphere Major volcanic eruptions can lower global temperature for a number of years

32. 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.

33. Fig. 19-7, p. 507 Stepped Art

34. Consequences of Climate Change  Increase in severe drought  Melting of ice and snow  Sea level rise  Biodiversity will decrease  Impacts on agriculture  Possible increase in disease

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

36. Areas of Glacial Ice Melting in Greenland during Summer 1982–2007 Increased

38. Greenland Ice Sheet Melting  https://www.youtube.com/watch?v=- EMCxE1v22I

39. Sea Level Rise  Sea level rise is caused by Expansion of warm water (thermal expansion of seawater) Melting of land-based ice

40. Sea Levels Are Rising  Projected effects of SLR Degradation of coastal estuaries, wetlands, and coral reefs Disruption of coastal fisheries Flooding Contamination of freshwater aquifers Submergence of low-lying land

41. Areas of Florida, U.S., to Flood If Average Sea Level Rises by One Meter

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

43. 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 – Positive Feedback Loop

44. Extreme Weather Will Increase in Some Areas  Heat waves and droughts in some areas  Prolonged rains and flooding in other areas  Will storms get worse? More studies needed  Hurricanes Katrina, Rita & Sandy

45. Global Warming Is a Major Threat to Biodiversity (1)  Most susceptible ecosystems Coral reefs Polar seas Coastal wetland High-elevation mountaintops Alpine and arctic tundra

46. Changes in Average Ocean Temperatures, Relative to Coral Bleaching Threshold

47. 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

48. Climate Change Will Threaten the Health of Many People  Deaths from heat waves will increase  Increase in some forms of air pollution  Greater instances of malaria

49. Discussion Dealing with climate change is difficult. Provide some reasons why you agree or disagree with this statement.

50. What Are Our Options?  Two approaches Drastically reduce the amount of greenhouse gas emissions Devise strategies to reduce the harmful effects of global warming

51. Group Work  Look over Chapter 19-3  Summarize some of our options for dealing with climate change.  Which of these options (or combination of these options) does your group think is the best?

52. Brainstorm  How can we reduce the threat of climate change?

53. Solutions: Global Warming, Methods for Slowing Atmospheric Warming

54. 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

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

56. Some Output Methods for Removing CO 2 from the Atmosphere and Storing It

57. Fig. 19-15, p. 516 Oil rig Tanker delivers CO 2 from plant to rig Coal power plant Tree plantation CO 2 is pumped down from rig for disposal in deep ocean or under seafloor sediments Abandoned oil field Switchgrass Crop field CO 2 is pumped underground Spent oil or natural gas reservoir Spent coal bed cavern Deep, saltwater-filled cavern = CO 2 pumping = CO 2 deposit

58. Case Study: Is Capturing and Storing CO 2 the Answer? (1)  Carbon capture and storage (CCS)  Several problems with this approach Power plants using CCS More expensive to build None exist Unproven technology Large inputs of energy to work Increasing CO 2 emissions

59. Case Study: Is Capturing and Storing CO 2 the Answer? (2)  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

60. Should We Use Geo-Engineering Schemes to Help Slow Climate Change? (2)  Remove HCl from seawater Effects on ecology?  Pump up nutrient-rich deep ocean water and cause algal blooms  Re-ice the Arctic  If any of these fixes fail, what about a rebound effect?

61. Governments Can Help Reduce the Threat of Climate Change  Strictly regulate CO 2 and CH 4 as pollutants  Cap-and-trade approach  Increase subsidies to encourage use of energy- efficient technology  Technology transfer

62. Governments Can Enter into International Climate Negotiations: The Kyoto Protocol  1997: Treaty to slow climate change  The Kyoto Protocol Reduce emissions of CO 2, CH 4, and N 2 O by 2012 to levels of 1990 Trading greenhouse gas emissions among countries Not signed by the U.S. President G.W. Bush’s reasons

63. We Can Move Beyond the Kyoto Protocol  2004: Stewart and Wiener New treaty needed  Should be led by the U.S.  Include the developing countries  Cap-and-trade emissions program  Set up 10 year goals

64. 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

65. Case Study: Reducing Greenhouse Gas Emissions in California  Use of energy-efficient appliances and buildings  Incentives for consumers to use less energy  Why is California suing the federal government?

66. Some Companies and Schools Are Reducing Their Carbon Footprints (1)  Major global companies reducing greenhouse gas emissions Alcoa DuPont IBM Toyota GE Wal-Mart Fluorescent light bulbs Auxiliary power units on truck fleets

67. Some Companies and Schools Are Reducing Their Carbon Footprints (2)  Colleges and universities reducing greenhouse gas emissions Oberlin College, Ohio, U.S. 25 Colleges in Pennsylvania, U.S. Yale University, CT, U.S.  What is your carbon footprint?  What can you do?

68. What Can You Do? Reducing CO 2 Emissions

69. We Can Prepare for the Harmful Effects of Climate Change (1)  Reduce greenhouse gas emissions as much as possible  Move people from low-lying coastal areas  Limit coastal building  Remove hazardous material storage tanks away from the coast

70. We Can Prepare for the Harmful Effects of Climate Change (2)  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

72. Fig. 19-17, p. 522 Develop crops that need less water Waste less water Connect wildlife reserves with corridors Move people away from low-lying coastal areas Move hazardous material storage tanks away from coast Stockpile 1- to 5-year supply of key foods Prohibit new construction on low-lying coastal areas or build houses on stilts Expand existing wildlife reserves toward poles

73. Animation: Greenhouse effect  https://www.outdoors.org/conservation/mountain watch/upload/greenhouse.swf

74. Animation: Increasing greenhouse gases

75. 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.

76. Our Use of Certain Chemicals Threatens the Ozone Layer  Ozone Thinning Seasonal depletion in the stratosphere Antarctica and Arctic  1930: Midgely Discovered the first CFC  1984: Rowland and Molina CFCs were depleting O 3  Other ozone-depleting chemicals

77. Global Average Total Ozone Values in the Stratosphere from 1979–2005

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

79. Natural Capital Degradation: Massive Ozone Thinning over Antarctica in 2007

80. Fig. 19-19, p. 524 Total ozone (Dobson units) 110220 330 440 550

81. 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

82. Summary of CFCs and Other Chlorine- Containing Compounds that Destroy Ozone

83. Fig. 19-D, p. 525 Sun Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl 3, breaking off a chlorine atom and leaving CFCl 2. UV radiation ClO + O → Cl + O 2 Repeated many times Cl + O 3 → ClO + O 2 Summary of Reactions CFCl 3 + UV → Cl + CFCl 2 Cl F C F Once free, the chlorine atom is off to attack another ozone molecule and begin the cycle again. Cl O O O Ozone O O O O O O A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O 2. O Cl O O O O The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO). O O Cl The chlorine atom attacks an ozone (O 3 ) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O 2 ). C

84. Why Should We Worry about Ozone Depletion?  Damaging UV-A and UV-B radiation Increase eye cataracts and skin cancer  Impair or destroy phytoplankton Significance?

85. Fig. 19-20, p. 524 Stepped Art

86. We Can Reverse Stratospheric Ozone Depletion (1)  Stop producing all ozone-depleting chemicals  60–100 years of recovery of the O 3 layer  1987: Montreal Protocol International treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion (CFCs)  1992: Copenhagen Amendment Additional controls should also be placed on methyl bromide, hydrobromofluorocarbons (HBFCs) and hydrochlorofluorocarbons (HFCs)

87. We Can Reverse Stratospheric Ozone Depletion (2)  Substitutes for CFCs are available  More are being developed

88. Animation: How CFCs destroy ozone  http://www.sciencescene.com/Environmental%2 0Science/Graphics/Flash%20Movies/ozone_des truction.swf