1. Discuss with your group: 1. Compare and Contrast Weather and Climate 2
Discuss with your group: 1. Compare and Contrast Weather and Climate 2. What causes wind?

2. Chapter 16 Global Climate Change

3. Statement: “It has been so hot this summer, must be that global warming”

4. Goals for Chapter 16 What is climate? What factors determine climate?
What causes seasonal changes?
What is the ozone layer and how is it being altered?
Describe how human actions are changing the make up of the Earth’s atmosphere and what are the potential consequence of that.

5. Section: Climate and Seasons
GOALS:
Explain the difference between weather and climate.
Identify four factors that determine climate.
Explain why different parts of the Earth have different climates.
Explain what causes seasons.

6. Why is our climate the way it is?

8. Weather
State of the atmosphere at any one time in a region

9. Climate
Climate: is the long-term average weather conditions in an area

11. 4 Factors that determine Climate
Latitude
Atmospheric Circulation (direction of the wind)
Ocean Circulation
Topography

12. Climate Factors Latitude:
the distance north or south from the equator impacts a regions climate
What is 0o?

13. Latitude

15. Latitude
Greenland at noon in the summer

16. Latitude
Dominican Republic Winter Sun

17. Climate Factors
2) Atmospheric Circulation: the direction the wind comes from impacts climate
Which way generally does wind blow across the U.S.?

18. Atmospheric Circulation
Prevailing Winds: winds that blow predominantly in one direction
Westerlies
Trade Winds
Polar Easterlies

19. Climate Factors
3) Ocean Circulation Patterns: Oceans carry heat from the equator or cool waters from the poles
Surface currents caused by winds

20. Climate Factors
3) Ocean Circulation Patterns: Oceans carry heat from the equator or cool waters from the poles
Surface currents caused by winds

21. Ocean Currents

22. Ocean Currents

23. Climate Factors
4) Topography: the shape of the land influences climate greatly
Mountains can impact temperature and precipitation patterns

24. Topography: Where do you think it snows the most in the U.S.?

25. Can it snow near the equator?

26. Topography

28. What causes seasonal changes?

29. When do we get the most direct sunlight?
Noon Sunlight

30. When do we get the most indirect sunlight?
Noon sunlight

31. When is the daylight hours longest and the shortest?
December 21st at 7 PM EST: WHY DOES IT LOOK LIKE THIS

32. What time of year is this? How do you know?

33. What 2 days of the year does it look like this: equal day and not all around the globe?

34. Seasons
Seasons: caused by the fact that Earth’s axis is tilted at 23.5o.

36. Section Review Explain the difference between weather and climate.
Identify four factors that determine climate.
Explain why different parts of the Earth have different climates.
Explain what causes seasons.

37. Section : Global Warming
GOALS:
Explain how the greenhouse effect works
Describe why carbon dioxide is important in the atmosphere, but why scientists find it troubling that levels are rising
Analyze what a warmer world might look like
DO NOT CONFUSE OZONE DEPLETION WITH GLOBAL WARMING!!!

38. Has Earth’s Climate Always Been Like Today’s?
How is it possible that you can find shark teeth far from the ocean inland?
How is it possible that you find fossils of Palm Trees in parts of Canada?
Today, global average temp = 59oF

39. Has Earth’s Climate Always Been Like Today’s?
Over past 4.7 billion years climate has changed by
Volcanic eruptions
Changes in solar output
Continents moving
Meteorites
Natural variations in CO2
Some changes slow, some quickly

41. Why does a greenhouse stay warm in the winter?
Why does the inside of the car heat up quickly on a sunny day?

42. Greenhouse Effect
Naturally occurring process in the atmosphere where gases trap in heat.
Like a blanket covering planet
Known about for over a century
Without it Earth would be COLD

43. Greenhouse Gases Major greenhouse gases include Carbon Dioxide
Water Vapor
Methane
CFCs
All act to trap in heat

44. Greenhouse Effect

45. We know from the past that CO2 levels tied closely to temperature

47. We know from the past that CO2 levels tied closely to temperature

48. Measuring CO2 Since 1958 in Mauna Loa Hawaii
What does this data show?
What trends does it show?
Why does it go up and down each year?

49. CO2 rates rising quickly
ppm
ppm
ppm
Chemist Charles Keeling’s CO2 measurements
Why measure here?

50. Rising CO2 Levels
Most CO2 in atmosphere is coming from burning fossil fuels like coal, oil and natural gas
Never 390 ppm in last 420,000 years (possibly 20 million)
Continue to rise rapidly
WHAT DOES THAT MEAN FOR THE FUTURE?

52. Where is the CO2 Coming From?
42% Coal powerplants
24% transportation
20% industrial processes
14% residential and commercial usages
Exhale, drive, turn on light, burn log in fire
1 gallon of gas burned equals 20 pounds of CO2

53. Where is the CO2 Coming From?
4.6% of the world’s population, yet 24% of emissions of CO2
From just U.S. coal burning exceeds 146 other nations with 3/4th of world population
Per capita yearly 500 tons

54. What do these graphs tell you?

55. What do higher CO2 levels mean for our future climate?

56. It’s All About Carbon

57. Global Warming
Earth’s global average temperature continues to rise due to the increase in greenhouse gases in the atmosphere

58. Global Warming
Earth’s global average temperature continues to rise due to the increase in greenhouse gases in the atmosphere

60. How Can You Predict The Future?
Very Complex Computer Models
Those models are saying…
It is likely that the world will warm 1.4oC to 5.8oC (2.5oF to 10.4oF) between 2000 and 2100

62. Why Care? I would like a warmer winter, and I Love Beach Weather

63. WHY CARE? It’s not like I can do anything. Plus, I Love my car.
Some potential benefits of global warming

64. Consequences of a Warmer Earth
1) A Grand Experiment With Potentially Major Changes
2) Melting Ice = Higher Seas
3) Change in Weather Patterns
4) Human Health Problems
5) Agriculture Changes
6) Effects to plants and animals

65. Both photos show Sperry Glacier in Montana’s Glacier National Park
Both photos show Sperry Glacier in Montana’s Glacier National Park. Top: 1913:
Bottom: 2008

68. Many major cities in the world are below, near or just above sea level.

69. Florida after sea level rise of 5 meters

71. Impacts on Organisms
Habitats shift, usually toward the poles or to higher altitudes.
Migrations start earlier in the spring.
Loss of ice makes hunting seals difficult for polar bears

72. Impacts on the Oceans
An increase in ocean temperature is associated with a process called coral bleaching.
Changes in ocean acidity, resulting from an increase in dissolved carbon dioxide, can harm organisms.

73. Reducing Risks

74. Improve Efficiency of Cars

77. International Agreements
What make Global Warming a difficult issue for political leaders to deal with?
1) Complex Issue
2) Consequences in Future
3) Need behavior changes
4) International
5) Wealth Companies

78. International Agreements
Why are international agreements needed?
What makes them hard to negotiate?
What differences exist between the developed and developing countries?

79. Kyoto Protocol
1997 International Treaty accepted by 160 countries to limit CO2 pollution
1990 levels by 2012
U.S. did not ratify
New treaties trying to negotiate

80. Global Warming: What does the future hold?

81. Section Review Explain how the greenhouse effect works
Describe why carbon dioxide is important in the atmosphere, but why scientists find it troubling that levels are rising
Analyze what a warmer world might look like
DO NOT CONFUSE OZONE DEPLETION WITH GLOBAL WARMING!!!
(What are some similarities/differences)

82. Agree or Disagree
Developed countries should help countries with tropical rain forests so those poorer countries can afford to leave their forests intact.
Carbon dioxide is a naturally occurring molecule and rising levels in our atmosphere should not be worried about.

83. Section : The Ozone Shield
GOALS:
Explain how the ozone layer shields the Earth from harmful radiation.
Describe how CFCs are damaging the ozone layer.
What are impacts for a thinner ozone layer.

84. Why is the atmosphere important?

85. Ozone Layer Ozone Layer:
An area of the stratosphere with high concentrations of ozone gas
Acts like a sun screen blocking out UV rays
Ozone = O3
Good ozone vs. Bad Ozone

88. Ozone Depletion Chlorofluorocarbons (CFCs) Man-made chemical
“Miracle Chemical”
Damages the ozone layer
Takes a LONG time to get to ozone layer and destroys many ozone molecules

90. CFCs
Used for decades
Each CFC molecule can destroy 100,000 ozone molecules over decades

92. Ozone Hole
Antarctic Ozone Levels

93. Impacts of Thinning Ozone Layer
Damage to skin cells (including skin cancers)
Damage to eyes
UV Light damages DNA
Kills phytoplankton (single-celled organisms) which are the base of most ocean food chains
UV light damages crops

95. Protecting the Ozone Layer
Montreal Protocol: international agreement in 1987 to phase out CFC usage
Second conference in 1992 in Copenhagen
WHY WILL IT STILL BE A PROBLEM FOR MANY MORE DECADES?

97. Section Review
Explain how the ozone layer shields the Earth from harmful radiation.
Describe how CFCs are damaging the ozone layer.
What are impacts for a thinner ozone layer.
DO NOT CONFUSE OZONE DEPLETION WITH GLOBAL WARMING!!!
(What are some similarities/differences)