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					Climate Change and Ozone Loss


                  G. Tyler Miller’s
             Living in the Environment
                     13th Edition

                            Chapter 18

Allison Turza; JL Mann High School
Key Concepts
 How does the Earth’s climate fluctuate
 What factors affect climate
 What are the possible effects of global warming
 What can humans do about potential climate
  change
 How are human activities affecting the ozone
  layer
 What can humans do about changes in the ozone
  layer
Past Climate Change

 Past global
  temperatures


 Recent trends in
  global temperatures



        Fig. 18-2 p. 447
The Natural Greenhouse Effect

Greenhouse effect Greenhouse gases
                    (Refer to Table 18-1 p. 448)




 Fig. 6-13 p. 128
Climate Change and Human Activities

Increased use of fossil fuels

Deforestation       Refer to Table 18-2 p. 451

Global warming

Melting icecaps and glaciers

Coral reef bleaching
Projecting Future Changes in Earth’s
Climate

 Climate models
  (see Spotlight p. 457)


 Apparent influence
  of human activities

 Could be natural
  changes
                           Fig. 18-11 p. 455
Factors Affecting Changes in Earth’s
Average Temperature
 Changes in solar output

 Changes in Earth’s albedo   Fig. 18-13 p. 458


 Moderating effect of
  oceans

 Clouds and water vapor

 Air pollution
Solutions: Dealing with the Threat
of Climate Change          Fig. 18-20 p. 466


Options
 Do nothing
 Do more research
 Act now to reduce
  risks
 No-regrets strategy
Reducing Greenhouse Gas Emissions


 Rio Earth Summit (1992)


 Kyoto Treaty (1997)


 Some US CO2 Reductions

          Refer to Fig. 18-25 p. 472
Ozone Depletion in the Stratosphere

Importance of Ozone
 Terrestrial life

 Reduce sunburn

 Prevents tropospheric
  ozone



                          Fig. 18-26 p. 473
Ozone Depleting Chemicals

Chlorofluorocarbons (CFCs)
Halons
Methyl bromide
Carbon tetrachloride
Methyl chloroform
Hydrogen chloride
…Sources of CFCs?
Seasonal Thinning at the Poles

Ozone thinning (hole) Polar vortex




             Fig. 18-30 p. 475
Reasons for Concern
 Increased incidence and severity of sunburn

 Increase in eye cataracts

 Increased incidence of skin cancer
                                 Refer to
 Immune system suppression      Fig. 18-32 p. 476

 Increase in acid deposition

 Lower crop yields and decline in productivity
Solutions: Protecting the Ozone Layer

CFC substitutes (see Table 18-3 p. 477)
Techno-fixes
Montreal Protocol



       Fig. 18-33 p. 479

				
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