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ATMO 336 – Section 001
Exam 3 – Fall 2007
Name__________________________
Multiple Choice Section (2.5 points each)
1. The climate of a particular region on Earth is fully described by the average temperature and
average precipitation (called “normals”) compiled over a 30-year period.
(a) True
(b) False
2. We have had a warm November in Tucson. Record high temperatures were set on November
5, 7, 18, and 19. These facts prove that global warming is taking hold and that temperatures
will get even warmer if we continue to pollute the atmosphere with greenhouse gases.
(a) True
(b) False
3. Radiation energy from the Sun that strikes the top of Earth’s atmosphere can either be
absorbed or scattered (reflected) away to outer space. Which of the following is the most
correct breakdown for what happens to radiation energy from the Sun that strikes the top of
our atmosphere?
(a) 50% is scattered away; 50% is absorbed by ground surface and oceans; 0% is
absorbed by the atmosphere
(b) 30% is scattered away; 50% is absorbed by ground surface and oceans; 20% is
absorbed by the atmosphere
(c) 30% is scattered away; 35% is absorbed by the ground surface and oceans; 35% is
absorbed by the atmosphere
(d) 20% is scattered away; 80% is absorbed by the ground surface and oceans; 0% is
absorbed by the atmosphere
4. Most of the photons emitted from the surface of the Earth (land and oceans) __________ .
(a) are absorbed by atmospheric gases and clouds
(b) are reflected back to the surface by atmospheric gases and clouds
(c) go directly off into outer space
5. The concentration of carbon dioxide in the atmosphere has _________ since 1750.
(a) increased by about 10%
(c) approximately doubled
(b) increased by about 35%
(d) more than tripled
6. Rice cultivation and cattle raising are significant anthropogenic sources (due to human
activities) for the greenhouse gas _________ .
(a) CO2 (Carbon dioxide)
(c) CH4 (Methane)
(b) N2O (Nitrous oxide)
(d) CFCs (Chlorofluorocarbons)
7. Too bad the US did not agree to and sign the Kyoto Protocol, which was aimed at reducing
greenhouse gas emissions, because if we had, the world would not be faced with the problem
of global warming.
(a) True
(b) False
8. This feedback mechanism (described in lecture) is largely responsible for amplifying the
overall global average temperature increase predicted by climate models after greenhouse gas
concentrations in the atmosphere are increased.
(a) Snow/Ice albedo (reflectance) feedback
(c) Water vapor feedback
(b) Carbon dioxide fertilization feedback
(d) Cloud emission feedback
For Questions 9 and 10
The amount of carbon dioxide that is stored in the ocean surface waters depends on two things:
A. The ocean surface temperature. As the ocean surface temperature goes up, the amount of
CO2 dissolved in the oceans at equilibrium goes down. In other words, as the ocean
surface temperature warms, some of the dissolved CO2 in the ocean is released to the air.
B. The concentration of CO2 in the atmosphere. As the concentration of CO2 in the
atmosphere goes up, the amount of CO2 dissolved in the oceans at equilibrium goes up.
In other words, as CO2 is added to the atmosphere, some of it dissolves in the oceans.
Consider the following two steps as the beginning of a climate feedback cycle:
 Humans add CO2 to the atmosphere
 As a result, surface temperatures (land and ocean) begin to increase
9. Continuing with this feedback cycle, Process (A) above would act as a _____ feedback.
(a) positive
(b) negative
10. Continuing with this feedback cycle, Process (B) above would act as a ______ feedback.
(a) positive
(b) negative
11. Clouds have ________ influence on the surface temperature of the Earth
(a) a warming
(c) both a warming and a cooling
(b) a cooling
(d) neither a warming nor a cooling
12. 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
13. According to most climate models, if the concentration of CO2 in the atmosphere were
instantly doubled from what it was before the Industrial Revolution and then left unchanged,
the average surface temperature of the Earth would __________ .
(a) warm by about 30 C over a period of a few years
(b) warm by about 30 C over a period of about 100 years
(c) warm by about 3 C over a period of a few years
(d) warm by about 3 C over a period of about 100 years
14. Assuming that global average temperature continues to rise, the one side effect (of the
choices given) that we are most certain about is ______________ .
(a) the number of hurricanes will increase
(b) farming production in the U.S. will decline (too hot), but farming production in
Canada and Russia will increase (longer growing season).
(c) tropical diseases will spread further north and south away from the equator
(d) sea level will rise
15. The most recent IPCC report (released in 2007) concludes with ___ percent certainty that
most of the recent increase in global average temperature has been caused by anthropogenic
increases in greenhouse gases.
(a) 0
(b) 50
(c) 90
(d) 100
16. 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
17. 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) variations in Earth's orbit around the Sun
(d) volcanic eruptions which eject massive amounts of aerosols into the atmosphere
18. This was probably the warmest period in the last 15,000 years. During this period, the global
average temperature was probably warmer than it is today.
(a) Holocene Maximum
(c) Little Ice Age
(b) Medieval Warm Period
(d) Younger Dryas
19. Global average surface temperatures from 1990 through today are warmer than at any other
time since 1860. This statement is _______________ .
(a) almost certainly true
(b) believed to be true by many people, but it is difficult to back up with evidence
(c) not true; It is a scare tactic used by those who warn about the evils of modern society.
20. From about 1910-1940, the measured global average surface temperature _________ ; this
period _______ provide good evidence that the rise in global average temperature since 1900
is directly caused by anthropogenic greenhouse gas emissions.
(a) decreased significantly ; does not
(b) decreased significantly ; does
(c) increased slightly ; does
(d) increased slightly ; does not
21. From about 1940-1980, the global average surface temperature __________ ; one possible
explanation for this temperature trend is the production of sulfate aerosols from ________.
(a) decreased significantly ; higher ocean temperatures
(b) decreased significantly ; coal burning
(c) increased slightly ; coal burning
(d) increased slightly ; higher ocean temperatures
22. An overwhelming majority of atmospheric scientists believe that most of the recent rise in
global average surface temperature is directly caused by human activities … and if we
continue to emit greenhouse gases into the atmosphere, we can expect future catastrophe for
inhabitants of the Earth.
(a) True
(b) False
23. On May 1, which of the following locations will have the greatest number of daylight hours?
(a) Perth, Australia (32˚ South latitude)
(b) Tucson, Arizona (32˚ North latitude)
(c) McMurdo Station, Antarctica (77˚ South latitude)
(d) Galapagos Islands (0˚ latitude, Equator)
24. In Tucson (32 North latitude), the noon-time sun is _________ .
(a) south of straight up everyday of the year
(b) north of straight up everyday of the year
(c) north of straight up from March 21 – September 21 and south of straight up from
September 21 – March 21
(d) south of straight up from March 21 – September 21 and north of straight up from
September 21 – March 21
25. Which large-scale feature in the Earth’s precipitation pattern best explains the climate of
Tucson? In other words, Tucson is located in the region, named the __________ .
(a) Intertropical Convergence Zone (ITCZ)
(c) Polar front
(b) Subtropical high
(d) Polar high
For Questions 26 and 27
Wichita, Kansas and San Francisco, California are both located at 37.6 north latitude. Wichita
is located near the middle of the North American continent, while San Francisco is located on the
Pacific Ocean coast. For January, the average high temperatures of the two cities are 56 F and
40 F. For July, the average high temperatures are 93 F and 72 F.
26. Which location has the more intense sunshine and greater number of daylight hours during
the month of July? (Ignore differences that may be due to cloud cover or elevation)
(a) Wichita
(b) San Francisco
(c) Both cities should have about the same solar intensity and number of daylight hours
27. Which average high temperatures are associated with Wichita?
(a) Wichita, January average high 40 F and July average high 93 F
(b) Wichita, January average high 40 F and July average high 72 F
(c) Wichita, January average high 56 F and July average high 93 F
(d) Wichita, January average high 56 F and July average high 72 F
28. Compared with most cities in the US, Tucson has a large daily temperature spread
(difference between the high temperature and the low temperature). Which of the following
is NOT a reason why Tucson has a large daily temperature spread?
(a) Continental location (away from Oceans)
(b) Relatively low latitude location
(c) Relatively high altitude location
(d) Generally clear skies (lack of cloud cover)
Short Answer Section
Select and answer 5 out of the 7 questions. Each answer is worth 7 points. Be concise. You
should not need more than 2 or 3 sentences to answer each question. Write your answers on the
answer sheets provided. If you need more space, please use the back of the multiple choice
answer sheet.
1. Why did I define meaningful climate change to occur over small ecosystem-sized spatial
scales instead of defining it as a change in global average temperature? Current climate
models may be able to accurately predict changes in global average temperature, but cannot
accurately predict ecosystem-scale climate changes. Why is this a problem for climate
change impact studies?
2. How is the amount of carbon dioxide in the atmosphere changing and why is it changing?
What is the “missing sink” problem for atmospheric carbon dioxide.
3. 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, including climate changes that may be
caused by human actions. Briefly explain.
4. In the documentary, “An Inconvenient Truth”, Al Gore uses the correlation between past
temperature changes and carbon dioxide concentrations in the atmosphere as inferred from
ice core data (see graphs below) as evidence to make the prediction that because we have
caused carbon dioxide levels to be 379 ppm today (off scale on the graph below), there is no
doubt that global average temperature will rise to be off the chart as well. What is wrong
with using this correlation as evidence for Al Gore’s prediction?
5. Shown below are two different reconstructions of past changes in global average temperature
over the last 1000 years. The one on the left is known as the “hockey stick”, while the one
on the right was part of an in-class handout. How can these two reconstructions look so
different, and yet each is accepted as scientifically valid by many climate scientists? How
might the differences between these two temperature reconstructions influence how someone
views the present warming trend in global average temperature?
6. Recall the “shadow rule” with regard to ultraviolet exposure, which states “if your shadow is
longer than your body, then you probably don’t need to apply sunscreen.” Your shadow is
longer than your body when the solar angle is larger than 45. Using the plot of solar
declination provided below, roughly estimate the time period over which sunscreen is not
necessary at solar noon in Tucson (located at 32 North latitude) based on the shadow rule.
Your answer should be a date range, such as June 10 – August 27 for example. Be sure to
describe how you determined your answer.
7. Radiation from the sun contains photons of all visible colors of light. Explain why the disk
of the sun looks red at sunrise by describing what happens to visible photons on their journey
from the sun through space and through the atmosphere to your eyes.