Download (2 points) Your name:

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(2 points) Your name: _____________________________
(1 point) Your TA’s name (circle one):
Gus Jesperson
Jill Harris
Jennifer Webster
Jason Scullion
Midterm – ENVIR 100 Fall 2008 (100 points total)
You have 50 minutes to take this exam, or approximately 8 minutes for each page (not
including this one). Be sure to look at the point values and allocate your time
accordingly, ask questions if necessary, and make sure your answers are clearly legible.
Good luck!
For grading purposes:
Page 1 (this page,
out of 3):
Page 2 (out of 17):
Page 3 (out of 18):
Page 4 (out of 14):
Page 5 (out of 13):
Page 6 (out of 18):
Page 7 (out of 17):
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1) (5 points) Explain briefly how rising CO2 concentrations in the atmosphere affect the
earth’s “temperature balance” and lead to climate change. You must draw a picture.i
2) (2 points) By approximately how much are temperatures expected to rise per decade
in this century due to climate change? Please indicate if your answer is F or C.ii
3) (4 points) What are the two main reasons for uncertainty about how much global
temperatures will rise this century?iii
4) The Holocene is the term used by geologists to refer to the interglacial period that we
are currently in (and that has so far lasted for about 10,000 years).
a. (2 points) Define “interglacial.”
b. (2 points) Compared to glacial periods, interglacial periods in previous eras have
been (circle one: relatively long relatively short
about the same length )
c. (2 points) What has been an important cause of climate change in previous eras
(i.e., before the Holocene)?iv
3
5) (4 points) Briefly discuss how deforestation contributes to increasing atmospheric
CO2 levels. Your answer should include the word pool (or pools) in a way that makes
sense.v
6) (2 points) What is an estimate for the percentage of annual CO2 increase that is
related to deforestation?vi
7) (6 points) List three fluxes for carbon that involve trees and indicate whether each one
is a flux in to the trees or a flux out of the trees.vii
a. (Circle one: Flux in Flux out )
b. (Circle one: Flux in Flux out )
c. (Circle one: Flux in Flux out )
8) (2 points) Give an example of an impervious surface and its environmental impact.viii
9) (4 points) In the left-hand space below, draw a graphical example of linear growth. In
the right-hand space below, draw a graphical example of exponential growth.ix
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10) (14 points total) Here’s something that Yoram might say: “I’m not worried that we
might be running out of coal, I’m worried that we might not be running out of coal.”
a. Write a good short paragraph about the first part of this sentence (“I’m not
worried that we might be running out of coal”) that relates this to four things
(terms, ideas, readings, authors, people, metaphors, history, etc.) from class.
(One point for each connection, three points for overall paragraph flow.) x
b. Write a good short paragraph about the second part of this sentence (“I’m worried
that we might not be running out of coal”) that relates this to four things (terms,
ideas, readings, authors, people, metaphors, history, etc) from class.xi
5
11) (3 points) The Commute Game, the Prisoners’ Dilemma, and similar situations can all
be fit into a general “two-step” model involving two choices (A and B). One part of
the model (one “step”) is that each individual wants to choose B, regardless of the
choices made by others. What is the other part (the other step)?xii
12) (4 points) In ethics, what is the difference between empirical claims and normative
claims? Give one example of each.xiii
13) (2 points) What is the question of moral considerability about?xiv
14) (2 points) In terms of moral considerability, traditional ethical approaches have been
_____________. [Fill in the blank and then give one example of such an approach.]xv
15) (2 points) Give an example of how theories like the Land Ethic or Deep Ecology
contrast with traditional ethical approaches in terms of moral considerability.xvi
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16) (4 points) In approximate terms, i.e., within 15%, answer the following:xvii
a. What percentage of the world’s population lives in the U.S.?
b. What percentage of the world’s oil consumption is in the U.S.?
17) (5 points) Draw a graph that roughly describes how the global human population has
changed over the past 2000 years. We are not expecting you to know precise numbers
for all years, but your graph should have the right shape. Label your axes and indicate
(within 15%) the approximate human population in 2008.xviii
18) (7 points) Draw a graph describing the most likely path of world human population
growth between 1850 and 2100. Your graph should have the following elements:
Labels on the x and y axes (1 point); labels or arrows or other ways for your reader to
determine the approximate (within 20%) human population in the year 1850 and in
the year 2100 (2 points each); and an appropriate shape showing how populations are
likely to change during this period (2 points).xix
19) (2 points) During their debate in class, Steve Harrell and Sara Curran mentioned
important factors that will influence human population growth over the course of this
century. Name one. (For partial credit you can name some other influence.)xx
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20) (4 points) In the trophic pyramid below, label the four parts. (Just write your
answers on top of the arrows.)xxi
21) (4 points) The trophic pyramid looks that way because of the 10% rule. Describe this
rule and explain why it leads the trophic pyramid to have the shape it does.xxii
22) (4 points) The 10% rule is related to the phenomenon of bioaccumulation. Define
bioaccumulation and explain the relevance of the 10% rule.xxiii
23) (5 points) Briefly describe a trophic cascade. For full credit, describe the one in
Ripple and Beschta 2004 (“Wolves and the ecology of fear: Can predation risk
structure ecosystems?”). For partial credit, give a different example of a trophic
cascade.xxiv
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Carbon dioxide forms a “blanket” that prevents solar energy from being re-radiated back
into space. Here’s a good picture, from
http://www.environmentalsociety.ca/issues/climate/images/greenhouse-effect.jpg.
Grading: 2 points for drawing, 3 points for explanation. Full credit if they mention a
“blanket” effect and the fact that more energy enters than leaves. Points off if
explanation is unclear or inaccurate (1-2). Points off if drawing is not labeled well or is
unclear (1).
ii
Half a degree F per decade.
iii
Two points each for (a) uncertainty about how much CO2 and other GHG humans will
add to the atmosphere and (b) uncertainty about feedback loops and other scientific
impacts of those GHG additions.
iv
Two points for interglacial being a period between ice ages; two points for “relatively
short”; and two points for Milankovich Cycle or discussion of changes in the earth’s
orbit.
v
Forests are a pool of carbon. Burn the forests or cut them down and you get a flux out
from that pool and into the atmosphere. Two points for appropriate use of the term
“pool”, two points for describing how deforestation contributes to climate change.
vi
The correct answer is 25% (from IPCC 2007, FAQ 7.1), so two points for anything
between 20% and 30% (inclusive) and one point for anything between 10% and 40%
(inclusive).
vii
Answers include respiration (flux out), fire (flux out), decomposition (flux out),
photosynthesis (flux in). One point each answer and correct in/out designation.
viii
One point for example (e.g., asphalt), one point for example of environmental impact
(e.g., faster run-off, carries pollutants into waterways).
ix
Two points each for linear and exponential growth.
x
One point each for things like Julian Simon, “Plenty of Gloom”, historic fears that we
were going to run out of coal, the invisible hand, demand response, prices have
historically declined, etc. Three points for overall paragraph.
xi
One point each for things like tragedy of the commons, prisoners’ dilemma, climate
change, Ehrlich, IPCC, etc. Three points for overall paragraph.
xii
Everybody is better off if everybody chooses A instead of everyone choosing B. Two
points for the general idea, 3 points for a thorough answer like the one above. (“Everyone
is better off choosing A” only gets 2 points.)
xiii
Two points for the difference, one point each for the examples: empirical claims (“the
climate is warming”) are true or false, normative claims (“we should stop polluting the
earth”) are not provable.
xiv
Two points for “who counts” or something similar.
xv
One point for “anthropogenic”, one point for cost-benefit analysis or other example.
xvi
Two points for answer about, e.g., extending moral considerability to other species or
ecosystems.
xvii
Two points for anything between 3.8% and 5.2% (4.5% is the correct answer), one
point for 3% to 6%; and then two points for anything between 19% and 29% (24% is the
correct answer), one point for 15% to 33%.
i
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xviii
One point for axes, two points for sharp exponential growth (one point for weak
graph), two points for anything between 5.7 and 7.7 billion (6.7 billion is the correct
answer), one point for 4.7 to 8.7 billion.
xix
One point for labels on axes, two points for anywhere between 0.5 billion and 2 billion
in 1850 (1.2 billion people is correct, give 1 point for something else reasonable), two
points for anywhere between 7.5 and 10 billion in 2100 (8.4 billion is the median
estimate from the Lutz article, give 1 point for something else reasonable), one point for
showing rapid growth from 1850 to present, one point for showing flattening out (or even
declining slowly) towards the end of the century.
xx
Two points for urbanization, development, or educational opportunities for girls. One
point for something else that’s correct.
xxi
One point each for carnivore, omnivore, herbivore, plants or primary producers.
xxii
Two points for saying that the 10% rule says that e.g., it takes 10 pounds of flies to
make 1 pound of frog. Two points for saying that it takes lots of producers to feed one
herbivore, etc.
xxiii
Two points for definition (accumulation of chemicals as you go up the food chain),
two points for connection: bioaccumulation is related to the 10% rule because, e.g., 10
pounds of flies becomes 1 pound of frog, so if chemicals are lost at a smaller rate than
energy—say, 0%—then 1 pound of frog has the same chemical load as 10 pounds of
flies.
xxiv
Introduction of wolves scared elk away from streams, which allowed recovery of
trees and shrubs along streams, and that had follow-up effects on beavers, songbirds, etc.
5 points for great answer, 4 points for minor mistake, 3 points for major mistake or
multiple minor mistakes, 2 points for multiple major mistakes, 1 point for some
intelligent thought. Minus 2 for using a different example.