Part 1 -- Multiple Choice & fill-in-the-blanks

ATMO 336, section 001 -- Exam 3 Name ____________________

Fill in the Blank (2 Points Each)

1,2. Write down the two gases in the atmosphere of Earth that contribute most to the greenhouse effect, i.e., what are the two most important greenhouse gases?

Multiple Choice (2 Points Each)

3. The greenhouse effect on the planet Venus is ________ the greenhouse effect on the planet Earth.

(a) stronger than (b) weaker than

4. Since 1860, the 11 warmest years in terms of the measured global average surface temperature have occurred since 1990. Putting that together with the fact that greenhouse gas concentrations are higher now than at any time since 1860, scientifically proves that the recent increase in global average temperature has been totally caused by our emissions of greenhouse gases.

(a) True (b) False

5. Even though the global average temperature has increased since 1900, there has been no measurable rise in sea level since 1900.

(a) True (b) False

6. The northward and southward movements of air in the northern hemisphere (which is evident by looking at the 500 mb pattern of ridges and troughs) transports energy from the tropics (where there is a surplus of radiation energy) to the polar regions (where there is a deficit of radiation energy).

(a) True (b) False

Refer to the diagram at the bottom of the page to answer questions 7-8. It shows the major energy sources and sinks for the Earth's surface in a globally averaged sense.

7. How does the sum of the radiation energy input (from Sun and atmosphere) compare to the radiation energy output (emission from the Earth’s surface)?

(a) The radiation energy in must equal the radiation energy out

(b) The radiation energy in is larger than the radiation energy out

8. The arrow on the latent heat exchange has been left out. Which way should it point?

(a) Up, away from the surface (b) Down, toward the surface

9. Most of the radiation energy emitted from the surface of the Earth __________ .

(a) is reflected back to the surface by atmospheric gases and clouds

(b) is absorbed by atmospheric gases and clouds

10. Consider two cities located at the same latitude. On city is a coastal city (located on the ocean), while the other is an inland city (located away from the coast). In general, the coastal city will have _________ compared to the inland city.

a. Warmer summers and warmer winters

b. Warmer summers and colder winters

c. Colder summers and colder winters

d. Colder summers and warmer winters

11. The prevailing surface wind pattern near the west coast of the United States is for winds to blow from west toward east. These west winds encounter coastal mountain ranges that run north and south. Which of the following is true?

a. More clouds and precipitation are expected on the western slopes of the mountains.

b. More clouds and precipitation are expected on the eastern slopes of the mountains.

12. Which of the following is true near a large city?

a. In the late night just before sunrise, it will generally be warmer downtown than in the surrounding suburbs.

b. In the late night just before sunrise, it will generally be colder downtown than in the surrounding suburbs.

c. There is no significant difference in nighttime temperatures between downtown and the surrounding suburbs.

13. With regard to the carbon cycle, photosynthesis is a _______ for carbon stored in the atmosphere.

(a) source (b) sink

14. This winter season, Cleveland, OH broke its all-time snowfall record. This is a good argument that global warming is not occurring.

(a) True (b) False

15. An overwhelming majority of climate change scientists believe that as the global average temperature increases, hurricanes will increase in both frequency and intensity.

(a) True (b) False

16. The most recent ice age cycles on Earth (over the last two million years) were most likely triggered by ___________ .

a. changes in the positions of the continents

b. decreases in the energy output of the Sun

c. volcanic eruptions which eject massive amounts of aerosols into the atmosphere

d. variations in Earth's orbit around the Sun

17. Ice core samples taken from Antarctica have been used to estimate changes in surface temperatures and the atmospheric concentrations of carbon dioxide and methane. This data indicates that when the temperature is relatively warm, the amounts of carbon dioxide and methane are ___________ .

a. relatively high (positive correlation)

b. relatively low (negative correlation)

c. sometimes high, sometimes low (no correlation)

18. The answer to the previous question scientifically proves ___________ .

a. high amounts of carbon dioxide and methane cause warm temperatures

b. high amounts of carbon dioxide and methane cause cold temperatures

c. there is no relationship between the amounts of carbon dioxide and temperatures

d. none of the above, because due to the complexity of the climate system which includes feedbacks, scientists have been unable to establish a clear cause and effect relationship between the amounts of the greenhouse gases carbon dioxide and methane and changes in temperature

19. A land bridge connecting Russia with Alaska formed during an ________ when sea levels were ________ .

a. interglatial warm period ; much lower than today

b. interglatial warm period ; much higher than today

c. ice age ; much lower than today

d. ice age ; much higher than today

20. The largest part of the radiation energy emitted from the surface of the Sun is which type of radiation?

(a) Microwave (c) Infrared

(b) Visible (d) Ultraviolet

21. Cloud droplets scatter visible photons. Which of the following statements is true?

a. Clouds scatter blue photons more efficiently than red photons.

b. Clouds scatter red photons more efficiently than blue photons.

c. Clouds scatter all colors of visible photons with nearly equal efficiency.

22. The concentration of carbon dioxide in the atmosphere has _________ since 1750.

a. increased by about 10% c. doubled

b. increased by about 33% d. more than tripled

23. Rice cultivation and cattle raising are significant anthropogenic sources (due to human activities) for the greenhouse gas _________ .

(a) CO₂ (Carbon dioxide)

(b) CH₄ (Methane)

(d) CFCs (Chlorofluorocarbons)

24. On a per molecule basis, which greenhouse gas(es) is (are) the largest contributor(s) to the greenhouse effect [also called the global warming potential]?

a. Carbon dioxide

b. Methane

c. Nitrous oxide

d. CFCs and their substitutes

25. The most rapid rise increase in the concentration of carbon dioxide in the atmosphere in terms of percent increase per year occurred during which period?

26. Consider the following sequence of events:

n The Earth’s surface temperatures cool down

n More of the land surface becomes covered by snow

n With more snow cover, the Earth’s surface absorbs less radiation energy from the Sun and temperatures cool further

This is an example of a ___________

(a) negative feedback process in the climate system

(b) positive feedback process in the climate system

27. Consider the following sequence of events:

n Suppose human beings discover a way to remove CO₂ from the atmosphere. Using this process, we remove half of the CO₂ from the atmosphere.

n In response, many plants grow slower, in effect slowing down the rate of photosynthesis. This result is that CO₂ levels begin to rise.

This is an example of a ___________

(a) negative feedback process in the climate system

(b) positive feedback process in the climate system

28. Since 1860, the global average surface temperature ____________________ .

(a) has risen steadily to be about 0.8˚ C warmer today

(b) has fluctuated up and down, but overall is about 0.8˚ C warmer today

(d) has declined steadily to be about 0.8˚ C cooler today

29. Sulfate aerosols, linked to “dirty coal”, have been used to explain ______________.

(a) the cooling global temperatures found between 1940 and the late 1970s

(b) the warming global temperatures found between 1910 and 1940

(d) the recent rise in global temperatures after 1980

30. Prior to the Pleistocene Epoch, there is much evidence indicating that the average surface temperature of the Earth was much warmer than it is today, with no permanent polar ice caps.

(a) True (b) False

31. Which of the following past climatic periods on Earth ended most recently (around 1850)?

a. Climatic Optimum

b. Medieval Warm Period

c. Little Ice Age

d. Younger Dryas

32. Which of the following statement is NOT true concerning the medieval warm period?

a. It occurred roughly from 1100 – 1300 AD.

b. The Vikings established agricultural settlements on Greenland.

c. The global average surface temperature was about 5° C warmer than today.

33. We rely on computer models of global climate to predict what will happen as greenhouse gas concentrations in the atmosphere increase. Which statement about predictions of climate models is most correct?

a. Nearly all models predict that global average temperature will increase, but they differ in exactly how much warming will occur.

b. The model predictions are all over the place with respect to global average surface temperature – some models predict that global average temperature will increase, some models predict that global average temperature will decrease, and some models predict no change in global average temperature.

34. Evidence for past climate changes on Earth is overwhelming. However, a big difference today is that since 1990 the average surface temperature of the Earth seems to be increasing at a faster rate than at any time in Earth’s history.

(a) True (b) False

Short Answer Question – Everyone Must Answer (5 points)

Life on Earth can be said to be both fragile and robust with respect to climate changes that have occurred throughout the history of the planet (and those that may be caused by human actions). Briefly Explain. Write your answer in the space provided below the multiple choice answer section.

Short Answer Questions – Select 5 of 8 (7 Points Each)

1. You are outside watching the sunset and there are no clouds. While the Sun is still above the horizon, explain why you see red when you look toward the direction of the sun, but you see blue when your look up at the sky above your head.

2. The table below contains some climate information about two cities labeled as city A and city B. One is Tucson, Arizona and the other is Savannah, Georgia, which is on the Atlantic Ocean coast. Both cities are located at 32° North latitude. Which is Tucson and which is Savannah? List two factors that likely contribute to the differences in temperature extremes at the two locations. Briefly explain how each of these factors influence temperature extremes.

Climate Variable	City A	City B
Average high temperature for April 28	81° F	85° F
Average low temperature for April 28	56° F	52° F
Record high temperature for April 28	93° F	101° F
Record low temperature for April 28	42° F	36° F
Average rainfall for April	3.3 inches	0.3 inches

3. Assume that the average temperature in the lower atmosphere (near the ground) starts to increase. Further assume that as the temperature rises, the average relative humidity in the lower atmosphere stays the same. Under these conditions describe the water vapor feedback mechanism making sure to state whether it is a positive or negative feedback with respect to temperature changes near the ground. Would your answer change if the average dew point temperature in the lower atmosphere stays the same instead of the relative humidity?

4. This question has two unrelated parts (a) and (b). Make sure you answer both parts. (a) Question 8 in the multiple choice section concerned latent heat exchange. Briefly describe how latent heat exchange works, i.e., physically how is energy transferred (either from surface to atmosphere or atmosphere to surface depending on your answer to the multiple choice question)? (b) The overall effect of clouds on the surface temperature of the Earth is difficult to determine because they exert both a cooling effect and a warming effect. How do clouds act to cool the surface temperature of the Earth? How do clouds act to warm the surface temperature of the Earth?

5. In reference to the global warming debate, you often hear people say things like "So what if the average global temperature goes up by 3°? I wouldn’t mind if it were 3° warmer everyday in my hometown. I don't see how such a small change in global average temperature can have much impact on the Earth." Explain what is wrong with this way of thinking both on regional and global scales. As part of your answer, give three examples of important statistics that determine the climate of a region other than average temperature and average precipitation.

6. Explain the "missing sink" problem for atmospheric carbon dioxide. Be sure to mention what we do know well and what we do not understand. Is the “missing sink” a positive or negative feedback with respect to possible anthropogenic (human-caused) climate change? Explain.

7. Briefly compare and contrast how the world community has dealt with the problems of stratospheric ozone destruction, acid rain, and global warming. Why do you think the responses to each problem have been different?

8. A climate modeler claims that her global climate model has been able to accurately reproduce the rise in global average temperature that has occurred since 1860. The measured increases in greenhouse gases that took place from 1860 through today are input into the model as it runs. However, when you look at her results, you notice that the model predicts a steady rise in global average surface temperature from 1860 through 2004 of 0.8° C as shown in graph below. Did the model correctly reproduce the changes in global average temperature that have occurred? Make your best attempt to draw on the graph the actual temperature changes that occurred between 1860 and 2004 (draw your graph in the diagram below). Would you trust this model to predict future changes in global average surface temperature, say between 2005 and 2100? Explain your answers.