1. Global Atmospheric Changes
Chapter 9

2. Case Study Melting Ice and Rising Sea Levels
Antarctic Ice pack has lost 40% of volume since 1980
Muir Glacier, Alaska
Compare photographs from 1903 to 2004
Human-caused: increase in atmospheric CO2
from fossil fuel burning
Challenges of global atmospheric changes:
Climate change
Ozone depletion
Acid deposition

3. The Atmosphere and Climate
Learning Objectives:
Distinguish between Weather and Climate
Summarize the effects of solar energy on Earth’s temperature
Explain several reasons for regional precipitation differences

4. The Atmosphere and Climate
Weather
Conditions in the atmosphere at a given place and time. Varies hour to hour, day to day.
Temperature, atmospheric pressure, precipitation, cloudiness, humidity, wind.
Climate
Typical weather patterns that occur in a place over a period of years. Determined by:
Temperature (average and seasonal variability)
Precipitation (average and seasonal variability)

5. The Atmosphere and Climate
The Earth has many different climates
Organisms adapted to specific climates
Rapid changes to climates may lead to extinction and ecosystem degradation

6. The Atmosphere and Climate
Solar Radiation and Climate
Insolation = sunshine
Major determinant of climate
Makes life on Earth possible
Liquid water
Warm planet
Photosynthesis
Powers Earth’s biogeochemical cycles
Drives winds and ocean currents

8. The Atmosphere and Climate
Solar Radiation and Climate
Temperature changes with Latitude and Season
Based on the amount of sunlight received

10. The Atmosphere and Climate
Precipitation: any form of water that falls from the atmosphere
3 factors determine precipitation:
Amount of water in atmosphere
Geographic location
Topographic features

11. The Atmosphere and Climate
What a Scientist Sees: Rain Shadow

12. How do you distinguish between weather and climate?
What are the two most important climate factors?
What are some of the environmental factors that produce areas of precipitation extremes, such as rain forests and deserts?

13. Global Climate Change Learning Objectives:
List the five main greenhouse gasses and describe the enhanced greenhouse effect
Discuss some of the potential effects of global climate change
Give examples of strategies to mitigate or adapt to global climate change

14. Global Climate Change Earth’s average temperature is increasing
Based on daily measurements taken by:
Meteorological stations, weather balloons, sea-surface buoys
NOAA: global temperatures in1995 and 2001– 2009 may have been highest in the last 1000 yrs
Spring in Northern Hemisphere comes 6 days earlier than in 1959, Autumn comes 5 days later
Increase in heat waves, heat-related deaths
Sea levels rising, glaciers retreating, more severe hurricanes

16. Global Climate Change Scientific Consensus:
Human activities are largely responsible for current climate change
IPCC: United Nations Intergovernmental Panel on Climate Change Predicts
1.8 to 4.0 °C ( °F) increase in global temperature by 2100
Higher maximum temperatures
More hot days, fewer cold days
Increase in heat index
Changes in precipitation patterns

17. Global Climate Change Causes:
Increase of atmospheric gases due to human activities:
Greenhouse gases:
Carbon Dioxide (CO2)
Nitrous Oxide (N20)
Methane (CH4)
Chlorofluorocarbons (CFCs)
Ozone (O3)
Water (H2O) - steady amount-does not increase due to human activity

20. Global Climate Change Aerosols tend to cool the atmosphere
Reflect sunlight into space
Cooling effect much weaker than enhanced greenhouse effect
Human and natural causes of aerosols
Sulfur emissions from fossil fuels
Volcanic eruptions

22. Global Climate Change Effects: Sea-level rise
Polar ice caps and continental glacier melts
Warm water expands in volume
Changes in precipitation patterns
More droughts in some areas
More flooding in some areas
Fresh water availability

24. Global Climate Change Effects: Impacts on agriculture
Rising sea levels will flood deltas
Pests will become more prevalent
No irrigation water
Productivity may increase in some areas

25. Global Climate Change Effects: Impacts on human health
Heat-related illnesses
Disease-carrying mosquitoes will expand their range and transmit more malaria, Dengue fever, yellow fever

27. Global Climate Change Effects: Impact on biodiversity and ecosystems
Warmer oceans lead to decline in populations of krillsilverfishAdelie penguins
Warmer temperatures makes frogs more susceptible to fungal diseases
Polar seas, coral reefs, coastal wetlands, tundra
Ocean acidification
Coral bleaching

28. Environmental InSight

29. Environmental InSight

30. Global Climate Change Dealing with global climate change:
Mitigation
Moderation or postponement of effects by reducing greenhouse emissions
Adaptation
Response to changes caused by climate change
Will require a combination of both
Focus on CO2 reduction

31. Global Climate Change Mitigation Develop alternatives to fossil fuels
Reduce energy use
Increase energy efficiency
Plant and maintain forests
Carbon Management
Trap CO2 from smokestacks
Sequester CO2 into geological formations or depleted oil/gas wells

33. Global Climate Change Adaptation Move coastal settlements inland
Construct sea walls on coastal areas
Prevent saltwater intrusion
Find substitute crops to grow on warming land
Develop heat and drought resistant crops/trees
City planning
Sewer systems
Storm runoff

34. Global Climate Change What are greenhouse gasses?
What is the enhanced greenhouse effect? How does it affect global climate?
What are two examples of each of the approaches to global climate change:
mitigation and adaptation?

35. Ozone Depletion in the Stratosphere
Learning Objectives:
Describe the importance of the stratospheric ozone layer
Explain how ozone thinning takes place and relate some of its harmful effects
Relate how the international community is working to protect the ozone layer

36. Ozone Depletion in the Stratosphere
Ozone - O3
Human-made pollutant in troposphere
Natural component of stratosphere
Ozone layer shields Earth’s surface from UV radiation

37. Ozone Depletion in the Stratosphere

38. Ozone Depletion in the Stratosphere
Ozone thinning
Occurs naturally over Antarctica
Has become worse due to human activity
Ozone ‘hole’
70% reduction in O3 over Antarctica
10% reduction over Europe and N. America
Noticeable reduction over Arctic

39. Ozone Depletion in the Stratosphere

40. Ozone Depletion in the Stratosphere
Causes
CFCs: Freon
Coolants, aerosol propellants, Styrofoam
Halons: fire retardant
Methyl Bromide: pesticide
Methyl Chloroform: industrial solvent
Carbon Tetrachloride: industrial solvent
Nitrous Oxides: coal burning waste and fertilizer breakdown

41. Ozone Depletion in the Stratosphere
Effects
More UV reaches Earth’s surface
Ecosystem disruption, e.g., Antarctic phytoplankton
Damage to wildlife, e.g., Antarctic fish, amphibians
Human health problems: cataracts, skin cancer, lowered immunity

42. Ozone Depletion in the Stratosphere
Mitigation and Recovery
Worldwide bans and reductions in use
1978: US banned CFC use as propellants
1987: Montreal Protocol - 50% reduction by 1998
CFCs phased out by 1996 in developed countries
CFCs phased out by 2005 in developing countries
CFCs are extremely stable and continue to deplete stratospheric ozone decades after decades
Full recovery is expected sometime after 2050

43. What is the stratospheric ozone layer?
How does the ozone layer protect life on Earth?
What is stratospheric ozone thinning?
What role do CFCs play in ozone thinning?
What are two harmful effects of ozone depletion?

44. EnviroDiscovery
Attach link to video/animation if this becomes available

45. Acid Deposition Learning Objectives:
Define acid deposition and explain how acid deposition develops
Relate examples of the effects of acid deposition

46. Acid Deposition A type of air pollution
Sulfuric and nitric acids in precipitation
Dry acid particles that settle out of the air
Observed since the Industrial Revolution
Serious threat to the environment:
In US alone, annual damage of $10 billion
In China, acid deposition affects 40% of country

47. Acid Deposition How Acid Deposition Develops:
Sulfur and Nitrogen oxides released by fossil fuel use
Wind carries pollutants
Pollutants react with water in atmosphere
Forms acids (nitric and sulfuric)
Acids are precipitated as rain, sleet, fog, snow or as dry particles

49. Acid Deposition Effects of Acid Deposition
Decline in fish and bird populations
Decline in forest ecosystems
Damage to agriculture
Damage to metals, building materials, statues
Changes in soil chemistry
Acidity
Nutrient leaching

52. Acid Deposition Politics
Sulfur and Nitrous oxides produced in one place are transported and deposited hundreds of km away.
Midwestern states produce 50-75% of acid
deposition that pollutes New England and Canada
Coal burning pollution from England is blown away to Sweden and Norway
Who pays?

53. Acid Deposition Facilitating Recovery
Reducing emissions of Sulfur and Nitrous Oxides reduces acid deposition
Install scrubbers in smokestacks of coal-fired plants
Use clean-coal technologies when burning coal
Switch from high-sulfur to low-sulfur coal
Reduce use of gasoline and diesel engines

54. What is acid deposition?
What are the main sources of atmospheric acid?
What are the harmful effects of acid deposition on materials, aquatic organisms, and soils?
Why does managing acid deposition often require international cooperation?

55. Case Study International Implications of Global Climate Change
Social, economic, political factors
Per capita emissions much higher in developed than developing countries,
Population sizes tend to be larger in developing countries
Emissions must be reduced, but vast disagreement because fossil fuels are seen as route to industrial development.