1. Chapter 19 Climate Control and Ozone Depletion

2. Science Focus: Melting Ice in Greenland
Largest island: 80% composed of glaciers
10% of the world’s fresh water
Glacial melting and movement accelerating
Effect on sea level if melting continues
1 meter rise by 2100

3. 19-1 How Might the Earth’s Temperature and Climate Change in the Future?
Concept 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.

4. Weather and Climate Are Not the Same
Weather is short-term changes
Temperature
Air pressure
Precipitation
Wind
Climate is average conditions in a particular area over a long period of time
Fluctuations are normal

5. Climate Change is Not New (1)
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
Changing global air and ocean circulation
Over the past 900,000 years
Glacial and interglacial periods

6. Climate Change is Not New (2)
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

7. Estimated Changes in the Average Global Temperature of the Atmosphere
Figure 19.2: Science.
The global average temperature of the atmosphere near the earth’s surface has changed significantly over different periods of time. The two graphs in the top half of this figure are rough estimates of long- and short-term global average temperatures, and the two graphs on the bottom are estimates of changes in the average temperature of the earth’s lower atmosphere over thousands of years. They are based on scientific evidence that contains gaps, but they do indicate general trends. Question: Assuming these are good estimates, what are two conclusions you can draw from these graphs? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Administration, National Center for Atmospheric Research, and National Oceanic and Atmospheric Administration)
Fig. 19-2, p. 494

8. Average surface temperature (°C)17 16 15 14
Average surface temperature (°C) 13 12 11 10
Figure 19.2: Science.
The global average temperature of the atmosphere near the earth’s surface has changed significantly over different periods of time. The two graphs in the top half of this figure are rough estimates of long- and short-term global average temperatures, and the two graphs on the bottom are estimates of changes in the average temperature of the earth’s lower atmosphere over thousands of years. They are based on scientific evidence that contains gaps, but they do indicate general trends. Question: Assuming these are good estimates, what are two conclusions you can draw from these graphs? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Administration, National Center for Atmospheric Research, and National Oceanic and Atmospheric Administration) 9
900
800
Present
Thousands of years ago
Fig. 19-2a, p. 494

9. Average surface temperature (°C)
15.0
14.8
14.6
14.4
Average surface temperature (°C)
14.2
14.0
13.8
13.6
Figure 19.2: Science.
The global average temperature of the atmosphere near the earth’s surface has changed significantly over different periods of time. The two graphs in the top half of this figure are rough estimates of long- and short-term global average temperatures, and the two graphs on the bottom are estimates of changes in the average temperature of the earth’s lower atmosphere over thousands of years. They are based on scientific evidence that contains gaps, but they do indicate general trends. Question: Assuming these are good estimates, what are two conclusions you can draw from these graphs? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Administration, National Center for Atmospheric Research, and National Oceanic and Atmospheric Administration)
1880
Year
Fig. 19-2b, p. 494

10. TEMPERATURE CHANGE (over past 22,000 years)
Agriculture established 1 -1
Temperature change (°C)
End of last ice age -2 -3
Average temperature over past 10,000 years = 15°C (59°F) -4
Figure 19.2: Science.
The global average temperature of the atmosphere near the earth’s surface has changed significantly over different periods of time. The two graphs in the top half of this figure are rough estimates of long- and short-term global average temperatures, and the two graphs on the bottom are estimates of changes in the average temperature of the earth’s lower atmosphere over thousands of years. They are based on scientific evidence that contains gaps, but they do indicate general trends. Question: Assuming these are good estimates, what are two conclusions you can draw from these graphs? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Administration, National Center for Atmospheric Research, and National Oceanic and Atmospheric Administration) -5
20,000
10,000
2,000
1,000
200
100
Now
Years ago
Fig. 19-2c, p. 494

11. Temperature change (°C)
0.5
0.0
Temperature change (°C)
-0.5
Figure 19.2: Science.
The global average temperature of the atmosphere near the earth’s surface has changed significantly over different periods of time. The two graphs in the top half of this figure are rough estimates of long- and short-term global average temperatures, and the two graphs on the bottom are estimates of changes in the average temperature of the earth’s lower atmosphere over thousands of years. They are based on scientific evidence that contains gaps, but they do indicate general trends. Question: Assuming these are good estimates, what are two conclusions you can draw from these graphs? (Data from Goddard Institute for Space Studies, Intergovernmental Panel on Climate Change, National Academy of Sciences, National Aeronautics and Space Administration, National Center for Atmospheric Research, and National Oceanic and Atmospheric Administration)
-1.0
Year
Fig. 19-2d, p. 494

12. Stepped Art AVERAGE TEMPERATURE (over past 900,000 years
TEMPERATURE CHANGE (over past 22,000 years
TEMPERATURE CHANGE (over past 1,000 years
Stepped Art
Fig. 19-2, p. 494

13. Science: Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers
Figure 19.3: Science.
Ice cores are extracted by drilling deep holes into ancient glaciers at various sites such as this one (left) near the South Pole in Antarctica. Thousands of these ice cores, containing valuable climate and other data, are stored in places such as the National Ice Core Laboratory in the U.S. city of Denver, Colorado (right). Scientists analyze tiny air bubbles, layers of soot, and other materials trapped in different layers of these ice cores to uncover information about the past composition of the lower atmosphere, temperature trends such as those shown in Figure 19-2, greenhouse gas concentrations, solar activity, snowfall, and forest fire frequency.
Fig. 19-3, p. 495

14. Our Climate, Lives, and Economies Depend on the Natural Greenhouse Effect
Greenhouse gases absorb heat radiated by the earth
The gases then emit infrared radiation that warms the atmosphere
Without the natural greenhouse effect
Cold, uninhabitable earth

15. Human Activities Emit Large Quantities of Greenhouses Gases
Since the Industrial Revolution
CO2, CH4, and N2O emissions higher
Main sources: agriculture, deforestation, and burning of fossil fuels
Correlation of rising CO2 and CH4 with rising global temperatures

16. Atmospheric Levels of CO2 and CH4, Global Temperatures, and Sea Levels
Figure 19.4: Science.
Atmospheric levels of carbon dioxide (CO2) and methane (CH4), as well as the global average temperature of the atmosphere near the earth’s surface and the average global sea level have changed drastically over the past 400,000 years. These data were obtained by analysis of ice cores removed at Russia’s Vostok Research Station in Antarctica. More recent ice core analyses from Antarctica in 2007 indicate that current levels of CO2 in the atmosphere are higher than at any time during the past 800,000 years. Carbon dioxide remains in the atmosphere for 80–120 years compared to about 15 years for methane. However, each molecule of methane has 25 times the warming potential of a molecule of carbon dioxide. These curves show general correlations between these different sets of data but do not establish a direct relationship among these variables. Question: What are two conclusions that you can draw from these data? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and F. Vimeux et al., Earth and Planetary Science Letters, vol. 203 (2002): 829–843)
Fig. 19-4, p. 496

17. CO2 concentration (ppm)
CO2 concentration (ppm)
CO2
Figure 19.4: Science.
Atmospheric levels of carbon dioxide (CO2) and methane (CH4), as well as the global average temperature of the atmosphere near the earth’s surface and the average global sea level have changed drastically over the past 400,000 years. These data were obtained by analysis of ice cores removed at Russia’s Vostok Research Station in Antarctica. More recent ice core analyses from Antarctica in 2007 indicate that current levels of CO2 in the atmosphere are higher than at any time during the past 800,000 years. Carbon dioxide remains in the atmosphere for 80–120 years compared to about 15 years for methane. However, each molecule of methane has 25 times the warming potential of a molecule of carbon dioxide. These curves show general correlations between these different sets of data but do not establish a direct relationship among these variables. Question: What are two conclusions that you can draw from these data? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and F. Vimeux et al., Earth and Planetary Science Letters, vol. 203 (2002): 829–843)
400,000
350,000
300,000
250,000
200,000
150,000
100,000
50,000
Year before present
Fig. 19-4a, p. 496

18. CH4 concentration (ppb)
800
700
CH4
600
CH4 concentration (ppb)
500
400
300
400,000
350,000
300,000
250,000
200,000
150,000
100,000
50,000
Figure 19.4: Science.
Atmospheric levels of carbon dioxide (CO2) and methane (CH4), as well as the global average temperature of the atmosphere near the earth’s surface and the average global sea level have changed drastically over the past 400,000 years. These data were obtained by analysis of ice cores removed at Russia’s Vostok Research Station in Antarctica. More recent ice core analyses from Antarctica in 2007 indicate that current levels of CO2 in the atmosphere are higher than at any time during the past 800,000 years. Carbon dioxide remains in the atmosphere for 80–120 years compared to about 15 years for methane. However, each molecule of methane has 25 times the warming potential of a molecule of carbon dioxide. These curves show general correlations between these different sets of data but do not establish a direct relationship among these variables. Question: What are two conclusions that you can draw from these data? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and F. Vimeux et al., Earth and Planetary Science Letters, vol. 203 (2002): 829–843)
Year before present
Fig. 19-4b, p. 496

19. Temperature change (°C)4° 2°
0° –2° –4° –6° –8° –10°
Temperature
Temperature change (°C)
400,000
350,000
300,000
250,000
200,000
150,000
100,000
50,000
Figure 19.4: Science.
Atmospheric levels of carbon dioxide (CO2) and methane (CH4), as well as the global average temperature of the atmosphere near the earth’s surface and the average global sea level have changed drastically over the past 400,000 years. These data were obtained by analysis of ice cores removed at Russia’s Vostok Research Station in Antarctica. More recent ice core analyses from Antarctica in 2007 indicate that current levels of CO2 in the atmosphere are higher than at any time during the past 800,000 years. Carbon dioxide remains in the atmosphere for 80–120 years compared to about 15 years for methane. However, each molecule of methane has 25 times the warming potential of a molecule of carbon dioxide. These curves show general correlations between these different sets of data but do not establish a direct relationship among these variables. Question: What are two conclusions that you can draw from these data? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and F. Vimeux et al., Earth and Planetary Science Letters, vol. 203 (2002): 829–843)
Year before present
Fig. 19-4c, p. 496

20. 20
Sea level
–20 –40 –60 –80 –100 –120
Sea level (m)
400,000
350,000
300,000
200,000
250,000
150,000
100,000
50,000
Figure 19.4: Science.
Atmospheric levels of carbon dioxide (CO2) and methane (CH4), as well as the global average temperature of the atmosphere near the earth’s surface and the average global sea level have changed drastically over the past 400,000 years. These data were obtained by analysis of ice cores removed at Russia’s Vostok Research Station in Antarctica. More recent ice core analyses from Antarctica in 2007 indicate that current levels of CO2 in the atmosphere are higher than at any time during the past 800,000 years. Carbon dioxide remains in the atmosphere for 80–120 years compared to about 15 years for methane. However, each molecule of methane has 25 times the warming potential of a molecule of carbon dioxide. These curves show general correlations between these different sets of data but do not establish a direct relationship among these variables. Question: What are two conclusions that you can draw from these data? (Data from Intergovernmental Panel on Climate Change, National Center for Atmospheric Research, and F. Vimeux et al., Earth and Planetary Science Letters, vol. 203 (2002): 829–843)
Year before present
Fig. 19-4d, p. 496

21. Stepped Art
Fig. 19-4, p. 496

22. Correlation of CO2 and Temperature
Figure 19.5: This graph compares atmospheric concentrations of carbon dioxide (CO2) and the atmosphere’s average temperature for the period 1880–2009. The temperature data show the average temperature by year as well as a mean of these data. While the data show an apparent correlation between these two variables, they do not firmly establish such a correlation. (Data from Intergovernmental Panel on Climate Change, NASA Goddard Institute for Space Studies, and NOAA Earth System Research Laboratory)
Fig. 19-5, p. 497

23. Average annual temperature Running mean CO2
15.0
400
Average annual temperature Running mean CO2
14.8
380
14.6
360
14.4
14.2
340
Average surface temperature (°C)
Atmospheric CO2 concentration (ppm)
14.0
320
13.8
Figure 19.5: This graph compares atmospheric concentrations of carbon dioxide (CO2) and the atmosphere’s average temperature for the period 1880–2009. The temperature data show the average temperature by year as well as a mean of these data. While the data show an apparent correlation between these two variables, they do not firmly establish such a correlation. (Data from Intergovernmental Panel on Climate Change, NASA Goddard Institute for Space Studies, and NOAA Earth System Research Laboratory)
300
13.6
13.4
280
1880
1900
1920
1940
1960
1980
2000
2020
Year
Fig. 19-5, p. 497

24. CO2 Concentrations,
Figure 14, Supplement 9

25. Human Activities Play a Key Role in Recent Atmospheric Warming (1)
Intergovernmental Panel on Climate Change (IPCC), with 2010 updates
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

26. Human Activities Play a Key Role in Recent Atmospheric Warming (2)
Intergovernmental Panel on Climate Change (IPCC), with 2010 updates, cont.
1906–2005: Ave. temp increased about 0.74˚C
1970–2009: Annual greenhouse emissions from human activities up 70%
warmest decade since 1881
Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth
Melting of glaciers and increased floating sea ice
Last 100 years: sea levels rose 19 cm

27. Human Activities Play a Key Role in Recent Atmospheric Warming (3)
What natural and human-influenced factors could have an effect on temperature changes?
Amplify
Dampen

28. Melting of Alaska’s Muir Glacier between 1948 and 2004
Figure 19.6: Much of Alaska’s Muir Glacier in the popular Glacier Bay National Park and Preserve melted between 1948 and Mountain glaciers are now slowly melting throughout much of the world. Question: How might melting glaciers in Alaska and other parts of the world affect your life?
Fig. 19-6, p. 499

29. The Big Melt: Some of the Floating Sea Ice in the Arctic Sea
Figure 19.7: The big melt: Each summer, some of the floating ice in the Arctic Sea melts and then refreezes during winter. But in most recent years, rising average atmospheric and ocean temperatures have caused more and more ice to melt during the summer months. Satellite data show a 39% drop in the average cover of summer arctic sea ice between 1979 and In 2007 alone, the sea ice shrank by an area that was 6 times that of California, much more than in any year since 1979 when scientists began taking satellite measurements. If this trend continues, this summer ice may be gone by 2040, according to researchers Muyin Wang and James Overland, and perhaps earlier, according to a 2007 estimate made by NASA climate scientist Jay Zwally. Question: Do you think that the increased melting of floating arctic sea ice is part of a positive or negative feedback loop (see Figure 2-18, p. 49 and Figure 2-19, p. 50)? Explain. (Data U.S. Goddard Space Flight Center, NASA, National Snow and Ice Data Center)
Fig. 19-7, p. 499

30. Sept. 1979 Sept. 2007 Russia Russia North pole North pole Greenland
Alaska (U.S.)
Alaska (U.S.)
Canada
Canada
Stepped Art
Fig. 19-7, p. 499

31. Figure 19.7
Some projected effects of global warming and the resulting changes in global climate, based on the extent of warming and the total atmospheric concentrations of greenhouse gases in parts per million. According to the IPCC, a warming of 2 C° (3.6 F°) over 2005 levels is unavoidable, and an increase of at least 3 C° (5.4 F°) is likely sometime during this century (Figure 19-B). (Data from 2007 Intergovernmental Panel on Climate Change Report and Nicolas Stern, The Economics of Climate Change: The Stern Report, Cambridge University Press, 2006)
Stepped Art
Fig. 19-7, p. 507

32. Science Focus: How Valid Are IPCC Conclusions?
2500 scientists working for over two decades to reach consensus on climate change data and likely impact
Unanimity impossible to achieve
Gaps in data
Debate about interpreting data
Need for better models
2007 IPCC report and Nobel Prize

33. Science Focus: Using Models to Project Future Changes in Atmospheric Temperatures
Mathematical models used for projections
Global warming: rapid rate
Human factors are the major cause of temperature rise over the last 30 years
Always uncertainty with any scientific model

34. Simplified Model of Some Major Processes That Interact to Determine Climate
Figure 19.A: Science.
This is a simplified model of some major processes that interact to determine the average temperature and greenhouse gas content of the lower atmosphere and thus the earth’s climate. Red arrows show processes that warm the atmosphere and blue arrows show those that cool it. Question: Why do you think a decrease in snow and ice cover is adding to the warming of the atmosphere?
Fig. 19-A, p. 500

35. Natural and human emissions
Sun
Troposphere
Cooling from increase
Greenhouse gases
Heat and CO2 removal
Aerosols
CO2 emissions from land clearing, fires, and decay
Warming from decrease
CO2 removal
by plants and
soil organisms
Heat and CO2 emissions
Ice and snow cover
Figure 19.A: Science.
This is a simplified model of some major processes that interact to determine the average temperature and greenhouse gas content of the lower atmosphere and thus the earth’s climate. Red arrows show processes that warm the atmosphere and blue arrows show those that cool it. Question: Why do you think a decrease in snow and ice cover is adding to the warming of the atmosphere?
Shallow ocean
Land and soil biota
Long-term storage
Natural and human emissions
Deep ocean
Fig. 19-A, p. 500

36. Comparison of Measured Temperature from 1860–2008 and Projected Changes
Figure 19.B: Science.
This figure shows estimated and measured changes in the average temperature of the atmosphere at the earth’s surface between 1860 and 2008, and the projected range of temperature increase during the rest of this century (Concept 19-1). (Data from U.S. National Academy of Sciences, National Center for Atmospheric Research, Intergovernmental Panel on Climate Change, and Hadley Center for Climate Prediction and Research)
Fig. 19-B, p. 501

37. Change in temperature (°C)
5.0
4.5
4.0
3.5
3.0
2.5
Change in temperature (°C)
2.0
1.5
Figure 19.B: Science.
This figure shows estimated and measured changes in the average temperature of the atmosphere at the earth’s surface between 1860 and 2008, and the projected range of temperature increase during the rest of this century (Concept 19-1). (Data from U.S. National Academy of Sciences, National Center for Atmospheric Research, Intergovernmental Panel on Climate Change, and Hadley Center for Climate Prediction and Research)
1.0
0.5
Year
Fig. 19-B, p. 501

38. Individuals Matter: Sounding the Alarm – James Hansen
1988 appearance before Congress began debate over atmospheric warming
Promoted creation of IPCC
Climate scientist at NASA
Rising levels of greenhouse gases will lead to drastic climate disruption

39. James Hansen
Figure 19.C: James C. Hansen has been head of NASA’s Goddard Institute for Space Studies since As one of the world’s most respected climate scientists and climate modelers, he has made many important contributions to the science of atmospheric warming and projected climate disruption.
Fig. 19-C, p. 502

40. CO2 Emissions Play an Important Role (1)
From burning fossil fuels and forests
Abetted by deforestation; forests remove CO2 from the atmosphere
2010: 389 ppm
2050: 560 ppm
2100: 1,390 ppm
450 ppm as tipping point

41. CO2 Emissions Play an Important Role (2)
Largest emitters, 2009
China
United States
European Union (27 countries)
Indonesia
Russia
Japan
India

42. Cumulative CO2 emissions, 1900-2005
Figure 15, Supplement 9

43. Waste Heat Also Plays a Role in Climate Disruption
Burning any fuel creates heat
Many sources of heat
Power plants
Internal combustion engines
lights

44. What Role Does the Sun Play?
Researchers think atmospheric warming not due to an increase in energy output from the sun
Since 1975
Troposphere has warmed
Stratosphere has cooled
This is not what a hotter sun would do

45. What Role Do the Oceans Play in Projected Climate Disruption?
Solubility of CO2 in ocean water
Warmer oceans
Last century: C°increase
Absorb less CO2 and hasten atmospheric warming
CO2 levels increasing acidity
Affect phytoplankton and other organisms

46. There Is Uncertainty about the Effects of Cloud Cover on Global Warming
Warmer temperatures create more clouds
Thick, low altitude cumulus clouds: decrease surface temperature
Thin, cirrus clouds at high altitudes: increase surface temperature
Effect of jet contrails on climate temperature

47. Cumulus Clouds and Cirrus Clouds
Figure 19.8: Cumulus clouds (left) are thick, relatively low-lying clouds that tend to decrease surface warming by reflecting some incoming solar radiation back into space. Cirrus clouds (right) are thin and float at high altitudes; they tend to warm the earth’s surface by preventing some heat from flowing into space.
Fig. 19-8, p. 503

48. 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

49. 19-2 What Are Some Possible Effects of a Warmer Atmosphere?
Concept The projected rapid change in the atmosphere's temperature could have severe and long-lasting consequences, including increased drought and flooding, rising sea levels, and shifts in the locations of croplands and wildlife habitats.

50. Enhanced Atmospheric Warming Could Have Serious Consequences
Worst-case scenarios
Ecosystems collapsing
Low-lying cities flooded
Wildfires in forests
Prolonged droughts
More destructive storms
Glaciers shrinking; rivers drying up
Extinction of up to half the world’s species
Spread of tropical infectious diseases

51. Severe Drought Is Likely to Increase
Accelerate global warming, lead to more drought
Increased wildfires
Declining streamflows, dry lakes, lower water tables
Dry climate ecosystems will increase
Other effects of prolonged lack of water

52. More Ice and Snow Are Likely to Melt (1)
Why will global warming be worse in the polar regions?
Mountain glaciers affected by
Average snowfall
Average warm temperatures
99% of Alaska’s glaciers are shrinking
When mountain glaciers disappear, there will be far less water in many major rivers

53. More Ice and Snow Are Likely to Melt (2)
Glaciers disappearing from
Himalayas in Asia
Alps in Europe
Andes in South America
Greenland
Warmer temperatures

54. Shrinking Athabasca Glacier in Canada
Figure 19.9: This photo shows the melting and retreat of the Athabasca Glacier in the Canadian province of Alberta between 1992 and 2005.
Fig. 19-9, p. 506

55. Permafrost Is Likely to Melt: Another Dangerous Scenario
If permafrost in Arctic region melts
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

56. Projected Decreases in Arctic Tundra in Russia, 2004-2100
Figure 19.10: This figure shows a projected decrease in arctic tundra (see Figure 7-11, bottom, p. 157) in portions of eastern Russia between 2004 and 2100 as a result of atmospheric warming. The melting of permafrost in such tundra soils could release the greenhouse gases CH4 and CO2, and accelerate projected climate disruption, which would melt more tundra. This loss of arctic tundra could reduce grazing lands for caribou and breeding areas for a number of tundra-dwelling bird species. (Data from Intergovernmental Panel on Climate Change and 2004 Arctic Climate Impact Assessment)
Fig , p. 507

57. Current Boreal Forest RUSSIA ARCTIC TUNDRA
Figure 19.10: This figure shows a projected decrease in arctic tundra (see Figure 7-11, bottom, p. 157) in portions of eastern Russia between 2004 and 2100 as a result of atmospheric warming. The melting of permafrost in such tundra soils could release the greenhouse gases CH4 and CO2, and accelerate projected climate disruption, which would melt more tundra. This loss of arctic tundra could reduce grazing lands for caribou and breeding areas for a number of tundra-dwelling bird species. (Data from Intergovernmental Panel on Climate Change and 2004 Arctic Climate Impact Assessment)
Fig a, p. 507

58. 2090–2100
Boreal Forest
RUSSIA
Figure 19.10: This figure shows a projected decrease in arctic tundra (see Figure 7-11, bottom, p. 157) in portions of eastern Russia between 2004 and 2100 as a result of atmospheric warming. The melting of permafrost in such tundra soils could release the greenhouse gases CH4 and CO2, and accelerate projected climate disruption, which would melt more tundra. This loss of arctic tundra could reduce grazing lands for caribou and breeding areas for a number of tundra-dwelling bird species. (Data from Intergovernmental Panel on Climate Change and 2004 Arctic Climate Impact Assessment)
Fig b, p. 507

59. Boreal Forest ARCTIC TUNDRA Boreal Forest
Current
Boreal Forest
RUSSIA
ARCTIC TUNDRA
2090–2100
Boreal Forest
RUSSIA
Stepped Art
Fig , p. 507

60. Sea Levels Are Rising (1)
0.8-2 meters by 2100
Expansion of warm water
Melting of land-based ice
What about Greenland?

61. Sea Levels Are Rising (2)
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
Flooding of coastal cities

62. Areas of Florida to Flood If Average Sea Level Rises by One Meter
Figure 19.11: If the average sea level rises by 1 meter (3.3 feet), the areas shown here in red in the U.S. state of Florida will be flooded. (Data from Jonathan Overpeck and Jeremy Weiss based on U.S. Geological Survey Data)
Fig , p. 507

63. ALABAMA GEORGIA Tallahasee Jacksonville Pensacola Atlantic Ocean
Orlando
Gulf of Mexico
Tampa
FLORIDA
Fort Meyers
Figure 19.11: If the average sea level rises by 1 meter (3.3 feet), the areas shown here in red in the U.S. state of Florida will be flooded. (Data from Jonathan Overpeck and Jeremy Weiss based on U.S. Geological Survey Data)
Naples
Miami
Key West
Fig , p. 507

64. Low-Lying Island Nation: Maldives in the Indian Ocean
Figure 19.12: For a low-lying island nation like the Maldives in the Indian Ocean, even a small rise in sea level could spell disaster for most of its 295,000 people. About 80% of the 1,192 small islands making up this country lie less than 1 meter (3.2 feet) above sea level. Rising sea levels and higher storm surges during this century could flood most of these islands and their coral reefs.
Fig , p. 508

65. Extreme Weather Is Likely to Increase in Some Areas
Heat waves and droughts in some areas
Could kill large numbers of people
Prolonged rains and flooding in other areas
Will storms get worse?
More studies needed

66. Climate Disruption Is a Threat to Biodiversity (1)
Most susceptible ecosystems
Coral reefs
Polar seas
Coastal wetlands
High-elevation mountaintops
Alpine and arctic tundra

67. Climate Disruption Is a Threat to Biodiversity (2)
What about
Migratory animals
Forests
Which organisms could increase with global warming? Significance?
Insects
Fungi
Microbes

68. Exploding Populations of Mountain Pine Beetles in British Columbia, Canada
Figure 19.13: With warmer winters, exploding populations of mountain pine beetles have munched their way through large areas of lodgepole pine forest (orange-colored trees) in the Canadian province of British Columbia. Foresters are trying to reduce this threat by planting a mix of trees less susceptible to the pest—an example of applying the biodiversity principle of sustainability.
Fig , p. 509

69. Agriculture Could Face an Overall Decline
Regions of farming may shift
Decrease in tropical and subtropical areas
Increase in northern latitudes
Less productivity; soil not as fertile
Hundreds of millions of people could face starvation and malnutrition

70. A Warmer World Is Likely to 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 O3
More insects, microbes, toxic molds, and fungi

71. Detection of Dengue Fever in Mosquitoes, as of 2005
Figure 19.14: Areas in blue show counties in 28 U.S. states where one or both species of mosquitoes that transmit dengue fever have been found as of This supports the claim by some scientists that projected climate disruption will expand the range of mosquitoes that carry dengue fever, a debilitating and potentially deadly disease.
Fig , p. 510

72. 19-3 What Can We Do to Slow Projected Climate Disruption?
Concept To slow the projected rate of atmospheric warming and climate change, we can increase energy efficiency, sharply reduce greenhouse gas emissions, rely more on renewable energy resources, and slow population growth.

73. Dealing with Climate Disruption Is Difficult
Global problem with long-lasting effects
Long-term political problem
Harmful and beneficial impacts of climate change unevenly spread
Many proposed actions disrupt economies and lifestyles
Humans don’t deal well with long-term threats

74. Possible Climate-Change Tipping Points
Figure 19.15: Environmental scientists have come up with this list of possible climate change tipping points. They urge us to focus on avoiding these thresholds beyond which large-scale, irreversible, and possibly catastrophic climate changes can occur. The problem is that we do not know how close we are to such tipping points.
Fig , p. 511

75. Atmospheric carbon level of 450 ppm
Melting of all Arctic summer sea ice
Collapse and melting of the Greenland ice sheet
Severe ocean acidification, collapse of phytoplankton populations, and a sharp drop in the ability of the oceans to absorb CO2
Massive release of methane from thawing Arctic permafrost
Collapse and melting of most of the western Antarctic ice sheet
Severe shrinkage or collapse of Amazon rainforest
Figure 19.15: Environmental scientists have come up with this list of possible climate change tipping points. They urge us to focus on avoiding these thresholds beyond which large-scale, irreversible, and possibly catastrophic climate changes can occur. The problem is that we do not know how close we are to such tipping points.
Tipping point
Fig , p. 511

76. Science Focus: Science, Politics, and Climate
: increase from 30% to 48% of Americans who think global warming is exaggerated
Fossil fuel industries
Play on public’s lack of knowledge of
How science works
Difference between weather and climate

77. What Are Our Options? Three approaches
Drastically reduce the amount of greenhouse gas emissions
Devise strategies to reduce the harmful effects of global warming
Suffer consequences of inaction

78. Solutions: Slowing Climate Disruption
Figure 19.16: These are some ways to slow atmospheric warming and the resulting projected climate disruption during this century (Concept 19-3). Questions: Which five of these solutions do you think are the most important? Why?
Fig , p. 513

79. Slowing Climate Disruption
Solutions
Slowing Climate Disruption
Prevention
Cleanup
Cut fossil fuel use (especially coal)
Remove CO2 from smokestack and vehicle emissions
Shift from coal to natural gas
Store (sequester) CO2
by planting trees
Improve energy efficiency
Sequester CO2 in soil by using no-till cultivation
and taking cropland out
of production
Shift to renewable energy resources
Transfer energy efficiency and renewable energy technologies to developing countries
Sequester CO2 deep underground (with no leaks allowed)
Reduce deforestation
Sequester CO2 in the deep ocean (with no leaks allowed)
Figure 19.16: These are some ways to slow atmospheric warming and the resulting projected climate disruption during this century (Concept 19-3). Questions: Which five of these solutions do you think are the most important? Why?
Use more sustainable agriculture and forestry
Put a price on greenhouse gas emissions
Repair leaky natural gas pipelines and facilities
Reduce poverty
Use animal feeds that reduce CH4 emissions from cows (belching)
Slow population growth
Fig , p. 513

80. Individuals Matter: John Sterman’s Bathtub Model
Atmosphere as a bathtub
Inputs of CO2
Ways CO2 is removed from atmosphere

81. Bathtub Model of CO2 in Atmosphere
Figure 19.D: The bathtub represents the atmosphere. Inputs of CO2 have increased dramatically since the mid-1700s and are now entering the bathtub at nearly twice the rate at which the tub can drain. The tub drains into three major reservoirs: plants and soil, which absorb about 30% of daily outputs; the oceans, which take 25%; and sediments and rocks, which absorb less than 1%. Together, these reservoirs can absorb only about 55% of what is put into the tub every day by human activities. The other 45% is added to the tub, which is steadily filling—at a rate that some scientists say is beyond the level that is safe for most of life on earth.
Fig. 19-D, p. 512

82. 5 billion metric tons a year
450 parts per milion
tipping point)
390 —2010 average
271
Preindustrial level
200
100
5 billion metric tons a year
Figure 19.D: The bathtub represents the atmosphere. Inputs of CO2 have increased dramatically since the mid-1700s and are now entering the bathtub at nearly twice the rate at which the tub can drain. The tub drains into three major reservoirs: plants and soil, which absorb about 30% of daily outputs; the oceans, which take 25%; and sediments and rocks, which absorb less than 1%. Together, these reservoirs can absorb only about 55% of what is put into the tub every day by human activities. The other 45% is added to the tub, which is steadily filling—at a rate that some scientists say is beyond the level that is safe for most of life on earth.
Remains in atmosphere for up to 200 years
45%
Absorbed by plants and soils
30%
Excess CO 2 = 4.1 billion metric tons a year
Absorbed by oceans
25%
Absorbed by sediments and rocks
<1%
Fig. 19-D, p. 512

83. Prevent and Reduce Greenhouse Gas Emissions
Improve energy efficiency to reduce fossil fuel use
Increased use of low-carbon renewable energy resources
Stop cutting down tropical forests
Shift to more sustainable and climate-friendly agriculture

84. Collect Greenhouse Gas Emissions and Stash Them Somewhere
Solutions
Massive global tree planting; how many?
Restore wetlands that have been drained for farming
Plant fast-growing perennials on degraded land
Preserve and restore natural forests
Promote biochar
Seed oceans with iron to stimulate growth of phytoplankton
Carbon capture and storage – from coal-burning plants

85. Science Focus: Is Capturing and Storing CO2 the Answer?
Carbon capture and storage (CCS)
Several problems with this approach
Large inputs of energy to work
Increasing CO2 emissions
Promotes the continued use of coal (world’s dirtiest fuel)
Effect of government subsidies and tax breaks
Stored CO2 would have to remain sealed forever: no leaking

86. Capturing and Storing CO2
Figure 19.E: Solutions.
There are several proposed output methods for removing carbon dioxide from the atmosphere or from smokestacks and storing it in soil, plants, and deep underground reservoirs, as well as in sediments beneath the ocean floor. Questions: Which two of these solutions do you think would work best? Which two would be the least effective? Why?
Fig. 19-E, p. 515

87. Coal-burning power plant
Pipelines for pumping CO2
Depleted
coal bed
Figure 19.E: Solutions.
There are several proposed output methods for removing carbon dioxide from the atmosphere or from smokestacks and storing it in soil, plants, and deep underground reservoirs, as well as in sediments beneath the ocean floor. Questions: Which two of these solutions do you think would work best? Which two would be the least effective? Why?
Salt water aquifer
Depleted oil
and gas field
Fig. 19-E, p. 515

88. Some Propose Geo-Engineering Schemes to Help Slow Climate Change (1)
Last resort, if other methods and policies fail
Injection of sulfate particles into the stratosphere
Would it have a cooling effect?
Would it accelerate O3 depletion?
Giant mirrors in orbit around earth
Large pipes to bring nutrients from bottom of ocean to top to promote algae growth

89. Some Propose Geo-Engineering Schemes to Help Slow Climate Change? (2)
Doesn’t address the continued build-up of CO2 in the atmosphere
All depend on costly and complex plans
If any of these fixes fail, what about a rebound effect?

90. Governments Can Help Reduce the Threat of Climate Disruption
Strictly regulate CO2 and CH4 as pollutants
Carbon tax on fossil fuels
Cap-and-trade approach
Increase subsidies to encourage use of energy-efficient technology
Technology transfer

91. Trade-Offs: Carbon and Energy Taxes
Figure 19.17: Using carbon and energy taxes or fees to help reduce greenhouse gas emissions has advantages and disadvantages. Question: Which two advantages and which two disadvantages do you think are the most important and why?
Fig , p. 516

92. Carbon and Energy Taxes
Trade-Offs
Carbon and Energy Taxes
Advantages
Disadvantages
Simple to administer
Tax laws can get complex
Clear price on carbon
Vulnerable to loopholes
Figure 19.17: Using carbon and energy taxes or fees to help reduce greenhouse gas emissions has advantages and disadvantages. Question: Which two advantages and which two disadvantages do you think are the most important and why?
Covers all emitters
Doesn’t guarantee lower emissions
Predictable revenues
Politically unpopular
Fig , p. 516

93. Trade-Offs: Cap and Trade Policies
Figure 19.18: Using a cap-and-trade policy to help reduce greenhouse gas emissions has advantages and disadvantages. Question: Which two advantages and which two disadvantages do you think are the most important and why?
Fig , p. 516

94. Clear legal limit on emissions Revenues not predictable
Trade-Offs
Cap and Trade Policies
Advantages
Disadvantages
Clear legal limit on emissions
Revenues not predictable
Vulnerable to cheating
Rewards cuts in emissions
Figure 19.18: Using a cap-and-trade policy to help reduce greenhouse gas emissions has advantages and disadvantages. Question: Which two advantages and which two disadvantages do you think are the most important and why?
Rich polluters can keep polluting
Record of success
Low expense for consumers
Puts variable price on carbon
Fig , p. 516

95. Science Focus: What Is a Pollutant?
A chemical or any other agent that proves harmful to the health, survival, or activities of humans or other organisms
Carbon dioxide now classified as a pollutant
Concentration of carbon dioxide as the key factor

96. Governments Can Enter into International Climate Negotiations
The Kyoto Protocol
1997: Treaty to slow climate change
Reduce emissions of CO2, CH4, and N2O by 2012 to 5.2% of 1990 levels
Not signed by the U.S.
2009 Copenhagen
Nonbinding agreement

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

98. 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

99. 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?

100. What Can You Do? Reducing CO2 Emissions
Figure 19.19: Individuals matter.
You can reduce your annual emissions of CO2. Question: Which of these steps, if any, do you take now or plan to take in the future?
Fig , p. 519

101. We Can Prepare for Climate Disruption (1)
Reduce greenhouse gas emissions as much as possible
Move people from low-lying coastal areas
Take measures against storm surges at coast
Cooling centers for heat waves

102. We Can Prepare for Climate Disruption (2)
Prepare for more intense wildfires
Water conservation, and desalination plants

103. Ways to Prepare for the Possible Long-Term Harmful Effects of Climate Disruption
Figure 19.20: Solutions.
There are many ways for us to prepare for the possible long-term harmful effects of climate disruption. Questions: Which three of these adaptation plans do you think are the most important? Why?
Fig , p. 520
Fig , p. 520

104. Develop crops that need less water
Waste less water
Connect wildlife reserves with corridors
Move people away from low-lying coastal areas
Stockpile 1- to 5-year supply of key foods
Move hazardous material storage tanks away from coast
Prohibit new construction on low-lying coastal areas or build houses on stilts
Figure 19.20: Solutions.
There are many ways for us to prepare for the possible long-term harmful effects of climate disruption. Questions: Which three of these adaptation plans do you think are the most important? Why?
Expand existing wildlife reserves toward poles
Fig , p. 520

105. A No-Regrets Strategy
What if climate models are wrong and there is no serious threat of climate disruption?
No-regrets strategy
Environmental benefits
Health benefits
Economic benefits
Reduce pollution and energy use
Decrease deforestation
Promote biodiversity

106. 19-4 How Have We Depleted O3 in the Stratosphere and What Can We Do?
Concept 19-4A Our widespread use of certain chemicals has reduced ozone levels in the stratosphere, which has allowed 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.

107. Our Use of Certain Chemicals Threatens the Ozone Layer
Ozone thinning
Seasonal depletion in the stratosphere
Antarctica and Arctic
Affects Australia, New Zealand, South America, South Africa
1984: Rowland and Molina
CFCs were depleting O3
Other ozone-depleting chemicals

108. Natural Capital Degradation: Massive Ozone Thinning over Antarctica in 2009
Figure 19.21: Natural capital degradation.
This colorized satellite image shows massive ozone thinning over Antarctica during several months in The center of this image shows a large area where the concentration of ozone has decreased by 50% or more. (Data from NASA)
Fig , p. 521

109. Individuals Matter: Rowland and Moline—A Scientific Story of Courage and Persistence
Research
CFCs are persistent in the atmosphere
Rise into the stratosphere over years
Break down under high-energy UV radiation
Halogens produced accelerate the breakdown of O3 to O2
Each CFC molecule can last years
1988: Dupont stopped producing CFCs
1995: Nobel Prize in chemistry

110. 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?

111. Natural Capital Degradation: Effects of Ozone Depletion
Figure 19.22: Decreased levels of ozone in the stratosphere can have a number of harmful effects. (Concept 19-4a). Questions: Which three of these effects do you think are the most threatening? Why?
Fig , p. 522

112. What Can You Do? Reducing Exposure to UV Radiation
Figure 19.23: Individuals matter.
You can reduce your exposure to harmful UV radiation. Question: Which of these precautions do you already take?
Fig , p. 523

113. We Can Reverse Stratospheric Ozone Depletion (1)
Stop producing all ozone-depleting chemicals
60–100 years of recovery of the O3 layer
1987: Montreal Protocol
1992: Copenhagen Protocol
Ozone protocols: prevention is the key

114. We Can Reverse Stratospheric Ozone Depletion (2)
Substitutes for CFCs are available
More are being developed
HCFC-22
Substitute chemical
May still be causing ozone depletion
2009: U.S. asks UN for mandatory reductions in HFC emissions through Montreal Protocol

115. Three Big Ideas
Considerable scientific evidence indicates that the earth’s atmosphere is warming, mostly because of human activities, and that this is likely to lead to significant climate disruption during this century that could have severe and long-lasting harmful consequences.

116. Three Big Ideas
Reducing the projected harmful effects of rapid climate disruption during this century requires emergency action to increase energy efficiency, sharply reduce greenhouse gas emissions, rely more on renewable energy resources, and slow population growth.
We need to continue phasing out the use of chemicals that have reduced ozone levels in the stratosphere and allowed more harmful ultraviolet radiation to reach earth’s surface.