Chapter 20
Climate Change and Ozone Depletion

Objectives

1.      Describe the greenhouse effect and what the Earth would be like without a greenhouse effect.  List the two predominant greenhouse gases.  List four greenhouse gases which have risen in the last few decades. List four human activities which contribute greenhouse gases to the atmosphere. Distinguish between greenhouse effect and global warming.

 

2.      Describe the pattern of the earth's average surface-temperature fluctuation throughout geologic time.  Describe the period the earth has been experiencing for the last 10,000 years.

 

3.      Describe the general trend of mean global temperature since 1860.  List two factors other than the greenhouse effect that may have contributed to the general temperature change. State the consensus science view about the relationship between observed temperature changes and the likelihood of global climate change brought on by human activities.

 

4.      Briefly describe projections of the major climate models regarding changes in mean surface temperature and average sea level. List eight important factors that lend considerable uncertainty to climate models and their projections.

 

5.      State the range of temperature change which could cause real damage to ecosystems.  Explain why a range so seemingly small can have such major consequences. Summarize the projections of possible effects of global warming on (a) food production, (b) water supplies, (c) forests, (d) biodiversity, (e) sea levels, (f) weather extremes, (g) human health, and (h) environmental refugees.

 

6.      Describe three schools of thought about global warming and how we as a human society should act. List seven strategies which would slow potential global warming, including both prevention and cleanup approaches.

 

7.      Describe the origin of stratospheric ozone and the role it plays in protecting life on Earth. Briefly describe changes which have been occurring in stratospheric ozone.

 

8.      Describe the scientific work on CFCs and their relationship to ozone. Describe the political response to the scientific information. Summarize the consensus science view of CFCs and stratospheric ozone. Summarize alternative views that have received much attention. Explain the significance of a critically thinking citizenry to the democratic process.

 

9.      Explain the potential consequences of ozone depletion.  Propose three ways for slowing  these changes.

 

Key Terms  (Terms are listed in the same font style as they appear in the text.)


chlorofluorocarbon (CFC) (p. 486)

freons

global climate change (p. 470)

global warming (p. 470)