1. Define the greenhouse effect. Explain how the greenhouse effect works in the present climate, considering each of the energy flux terms in the energy balance for the planet, for the atmosphere, and the surface.
2. Explain how the greenhouse effect would change if the current CO₂ concentration were doubled. Why would the surface temperature go up? Be sure to include the changes in each term of the energy balance.
3. On a global-average basis, would a 1% increase in the solar constant or a doubling of the current CO₂ concentration produce a larger radiative forcing of the climate system. Evaluate the change in the net flux at the tropopause and at the Earth's surface.  [This question is about forcing only - NOT about the response.]
4. Compare the diurnal, seasonal and latitudinal patterns of radiative forcing from solar constant and CO₂ concentration changes.
5. 9.1
6. 9.2
7. 9.4
8. 9.6
9. Explain at least two ways in which cloud feedbacks could result in a negative feedback reducing the climate sensitivity, and two ways in which clouds could be involved in a positive feedback. What do you think is the overall net effect of clouds on the climate sensitivity? Why?
10. Explain at least one way in which land surface interactions with the atmosphere could result in a negative feedback reducing the climate sensitivity, and one way in which land surface interactions could be involved in a positive feedback.

Prepared by Alan Robock (robock@envsci.rutgers.edu) - Last updated on October 19, 2008