1. Hour Exam #2 September 30, 2005

2. Using the decision trees (attached), show a series of steps where CH 3 OH would be converted to CO 2 (Partial Credit will be given). CH 3 OH + OH  CH 3 O + H 2 O  CH 3 O + O 2  O 2 H + CH 2 O CH 2 O (formaldehyde) + OH  H 2 O + CHO (could occur by UV radiation also) CHO + O 2  CO + O 2 H  CO + OH  HO-C-O HO-C-O + O 2  CO 2 + O 2 H

3. Based on the bonding strengths of the “loose” oxygen, identify those reactions that would occur in the troposphere. NO + O 2  NO 2 + O NO Cl + O 2  ClO + O NO NO + O 3  NO 2 + O 2 YES O 3 + O  2 O 2 YES ClO + NO  NO 2 + O 2 NO (products have no chlorine)

4. 10 pts. The figure on the right shows the light emitted from the earth’s surface and the light leaving the upper atmosphere as a function of wavelength. Explain why the two curves are not the same. Identify on the graph the regions of most concern when one is assessing the potential impact of a new gas to be released into the troposphere. The curves are not the same because of absorption of IR by “greenhouse” gases. The region of concern would be between 10 – 15  m where there is nothing currently absorbing.

5. The figure on the right shows a system that has reached a steady-state. Using CO 2 as the model, how would you expect the graph to change if we reduce the amount of gasoline we burn, and (b) explain how the graph would change if the oceans get warmer, reducing the amount of CO 2 absorbed. If we reduced the amount of gasoline we burn, I would expect the steady- state level to decrease, and on the other hand, I would expect the steady- state level to increase if we reduce the sink for the carbon dioxide.

6. The figure on the left shows a relative comparison of the contributions of greenhouse gases to global warming. How do you explain the relatively large contributions of CFCs and N 2 O when their concentrations are 1000 times less than CH4 and CO 2 ? How do you explain the negative contribution (cooling effect) of aerosols? The relative magnitude is a function of efficiency, where they absorb, and the residence time. These factors would influence the contribution. Aerosols reflect the incident light resulting in a cooling effect.

7. List four documented observations that support the position that the world is getting warmer.’ Documented global temperature rise since 1880 (0.3 to 0.6 Celcius over past century) Winters are getting shorter Accelerated melting of Alpine glaciers. A sea-level rise of 10 to 25 cm. over past 100 years. Coral bleaching caused by abnormally high sea-surface temperatures. The Earth’s ice cover is shrinking fast Mosquito-borne diseases have reached higher altitudes

8. At the G8 Summit meeting this summer, the leaders discussed global warming and the future development of Africa. They issued four statements and/or goals with regard to global warming. List two of them. First, Participants agreed that Climate Change was indeed a problem, with human activity contributing to it. Second, that the participating members had to tackle it with urgency. Third, that in order to do that, nations have to slow down, stop and in time reverse greenhouse gas emissions. Fourth, the participating nations put in place a new dialogue involving the G8, the emerging economies and the key international institutions to create a pathway to a post Kyoto agreement, so that when Kyoto expires after 2012, the world can act with unity.