B. The temperature would drop a few degrees and then stabilize, not cold enough to cause a new ice age, but cold enough to be unpleasant. C. The temperature would remain the same as it is now, which is about the same as it was before the industrial revolution. D. The temperature would drop a lot, causing a new ice age. E. The temperature would increase 30 or 40
degrees, and then stabilize at that new, warmer level. Doubling CO 2 is estimated to warm the Earth by between 1.5 and 4.5 oC, or 2.7 to 8.1oF, with some chance of slightly larger change and very little chance of smaller change. The physical basis of warming from CO 2 is quite well understood, and cooling or no response is very unlikely. You might compare the expected warming from CO 2 to getting up to put another blanket on the bed in the night if you are cold. True, you might spill a glass of water into the bed, or your significant other might steal the other blankets while you’re up, so getting the extra blanket might make you colder, but common sense says that getting the extra blanket warms you. Warming from CO 2 is about as certain as warming from the extra blanket—maybe a huge number of volcanoes will explode in the near future and offset the effects of the CO 2 , but don’t count on it. Points Earned: 1/1 Correct Answer: A Your Response: A 4. We humans are changing the composition of the atmosphere in many ways. Those changes will directly affect the planet’s temperature, but the resulting change in temperature will affect other things on the planet that also affect the planet’s temperature. Suppose that we could magically change the composition of the atmosphere enough to raise the temperature one degree if all other parts of the Earth system were held fixed, and after the warming, we allowed the other parts of the Earth system to react for a few years or decades. At the end of that time, what would be the total change in the Earth’s temperature? A. The Earth would end up cooler than before the human influence, as feedback processes oppose the tiny warming caused by the change in atmospheric composition. B. The Earth would end up one degree warmer than before the human influence, because positive and negative feedback processes would offset each other. C. The Earth would end up a few tens of degrees warmer than before the human influence, because positive feedbacks would amplify the original changes a whole lot. D. The Earth would end up a few degrees warmer than before the human influence, because positive feedbacks would amplify the original change. E. The Earth would end up warmer than before the
human influence but by less than one degree, because feedback processes would oppose the initial warming. Negative feedbacks stabilize the climate over long times of hundreds of thousands or millions of years or more, but feedbacks over years to millennia are mostly positive, amplifying changes. If there is a change in the sun, or CO 2, or something else sufficient by itself to raise the temperature by one degree, this will be amplified to a few degrees by feedbacks.
You've reached the end of your free preview.
Want to read all 11 pages?
- Fall '08
- Global Warming, Correct Answer, Coal, Pennsylvania