Each question below requires you to conduct a simple experiment with GEEBITT.

1. Because temperature becomes less sensitive to additional pCO2 the higher the initial concentration of CO2, it is estimated that an additional doubling of CO2 (to ~1480 ppm) will only increase surface temperature by another 3°C. By how much do you need to increase the GHF to increase temperature by another 3°C? (3 marks)

2. Set GHF =1.0. How sensitive is the surface temperature in the Snowball Earth scenario to a 10% change in albedo (i.e., how many degrees C does temperature change for every 10% change in albedo)? To help you answer this question, perform a series of calculations with GEEBITT, record your results in the table provided, and then plot albedo vs. surface temperature. (3 marks)

3. Which of the following plays the biggest role in modulating Earth's surface temperature: a 10% change in luminosity, a 10% change in albedo, or a 10% change in the GHF? Explain your answer. You should make some plots similar to that above using the Earth's information in the model. (5 marks)

4. Do you think this is representative of the factor that has the greatest overall effect on climate? Why or why not? (4 marks)