--> DUE in class on Friday, March 3 (please write neatly and large enough) 1. The following are approximate "techinical" statements made by global warming skeptics. Use your knowledge of climate science to explain what is false or irrelevant: a) Longwave radiation does not penetrate into the ocean below about 10 micrometers, so the enhanced greenhouse effect cannot contribute to the ocean heating (word added late). b) CO2 is a minor greenhouse gas compared to water vapor, so what if it doubles. c) This winter was exceptionally cold in Europe. How can there be global warming? d) The warming in the early century is not that much different from the warming in the last few decades and there is very weak warming from 1940-1970. This indicates the 20th century temperature trends are mostly driven by natural variability. 2. (a) What is the range of predicted temperature rise over the 21st century according to climate models? (b) What causes more uncertainty in the predictions: (i) uncertainty in the climate sensitivity, (ii) uncertainty in ocean heat uptake, or (ii) uncertainty in the greenhouse gas and aerosol levels? 3. (a) What has been the role of anthropogenically produced aerosols on the climate durring the 20th century? (b) What is their expected role in the 21st century? 4. According to the IPCC Summary for Policymakers, briefly summarize what you think is most compelling among the items cited as new and stronger evidence that the past warming is attributable to humans (p10). 5. What does the IPCC Summary for Policymakers say about extreme events in the future? |