Problem Set Chapter 5 CHM 4353 Spring 2013

1. (a) Given the atmospheric burden of carbon (as CO2) increases by about 4.7 Gt annually, calculate the increase in ppm concentration of carbon dioxide that this brings about. (b) Given the its total concentration was 382 ppm in 2006, calculate the total mass of CO2 that was present in the air. Note that the total mass od the atmosphere = 5.1x1021g, and the average molar mass of air is 29 g/mol. [Hint: Express the amount of CO2 and air as moles, and then convert to ppm

2. As the Earth warms, more water vapor is introduced into the atmosphere. Explain briefly how this can be viewed as both a negative and a positive feedback for global warming.

3. The steady-state conc. of a gas in the atmosphere is 6.2 μg/g of air, and it has a residence time of 12yrs. What is the total annual release of the gas (M.W. = 71g/mol) into the atmosphere?

4. List the important gases, which contribute to the greenhouse effect, in descending order according to their contribution to global warming:

5. If the average, steady state residence time of a trace atmospheric gas is 42.1 years and its input rate is 18.4 million kg/y, what is the total amount of it (kg) in the atmosphere?

6. Propose a solar radiation management method (not from the textbook)that would not significantly reduce natural rainfall amounts, and explain how this would be accomplished. (hint: consult primary and secondary literature)