Pre-class Quiz #2, which is based on these reading questions (and on Reading Assignment #2), is posted on iLearn. (A "non-interactive" version of Pre-class Quiz #2, suitable for printing and use while you do the corresponding reading, has been posted on both iLearn and the backup class Web site.)

From The Earth System, 3rd Ed., Chapter 3:
"Global Energy Balance: The Greenhouse Effect" (pp. 48-53)

• Key Questions: #3 (p. 36).
  
  
• Physical Causes of the Greenhouse Effect (pp. 48-50)
  
  
  1. To what gases is the greenhouse effect primarily attributable?
     
     Molecular Motions and the Greenhouse Gases H₂O and CO₂
     
  2. What is the defining property of a greenhouse gas?
  3. What determines the wavelengths of radiation that a molecule can absorb and emit?
  4. What wavelengths of radiation does H₂O vapor absorb well?
  5. What wavelengths does CO₂ gas absorb well?
  6. Where does the earth's wavelength of peak emission lie relative to the wavelengths absorbed well by H₂O and CO₂? Why is this important for earth's climate?
     
     Other Greenhouse Gases
     
  7. Besides H₂O and CO₂, what other gases in the earth's atmosphere contribute to the greenhouse effect?
  8. Why do these other gases contribute to the greenhouse effect to an extent disproportionate to their very small concentrations relative to H₂O and even CO₂?
  9. What is the window region in the atmospheric absorption spectrum?
  10. Do nitrogen gas and oxygen gas (O₂ and N₂, respectively), the dominant constituents of the atmosphere by far, contribute to the greenhouse effect? Why or why not?
      
      
• Effect of Clouds on the Atmospheric Radiation Budget (pp. 50-51)
  
  
  11. What other atmospheric constituents besides gases contribute to the greenhouse effect?
      
      Types of Clouds
      
  12. Why are the contributions of clouds to the greenhouse effect hard to calculate?
  13. What basic types of clouds are identified by our text? [There are a number of other types not identified at this point in the text.]
      
      Opposing Climatic Effects of Clouds
      
  14. What are the two primary, opposing mechanisms by which clouds affect climate?
  15. With clouds, the earth's albedo averages about 0.3 (that is, the earth reflects about 30% of the solar radiation striking it). Without clouds, what would the earth's albedo probably be (all else being equal)?
  16. How much warmer would the earth's effective radiative equilibrium temperature be without clouds (all else being equal)?
  17. Would the earth's average surface temperature be warmer by the same amount? Why or why not?
  18. Why are cloudy nights warmer than clear nights, all else being equal?
  19. Different cloud types affect climate differently. What effects on the earth's surface temperature do low, thick clouds (such as stratus clouds) have compared to high, thin clouds (such as cirrus clouds)?
      
      Earth's Global Energy Budget
      
  20. The details of the earth's energy budget described in this subsection and shown in Figure 3-19 (p. 52) are covered in class by Lab Activity #5. However, the materials for Lab Activity #5 come from a different text; are the two sets of energy budget values consistent with each other? (What is the publication date of the source for Figure 3-19?)
  21. What is the principle of planetary energy balance?
      
      
• Introduction to Climate Modeling (pp. 52-53)
  
  
  22. How do climate scientists try to predict the change in the greenhouse effect that would arise with changes in the concentrations of greenhouse gases?
  23. What is a general circulation model (GCM) or global climate model?
  24. As climate prediction tools, what is one of the drawbacks from which GCM's suffer?
      
      One-Dimensional Climate Models—RCMs
      
  25. What is a radiative-convective model (RCM)? What advantage does it have over a GCM?
  26. Why are RCMs referred to as "one-dimensional"? How are RCMs structured?
      
      Radiative Effect of Doubling Atmospheric CO₂
  27. What do the best current RCM's predict will happen to the earth's global average surface temperature if atmospheric CO₂ concentrations were to double from current levels?
  28. What general kinds of effects do RCMs not account for?
      
      
• Chapter Summary: #'s 2 and 3 (p. 55).
• Review Questions: #'s 9-11 (p. 56).
• Critical Thinking Problems: #6 (p. 54) [Note: this is not homework to turn in.]