Homework #4. Climate Graphs and Stabilization
Name____________________________
Environmental Science – 2017
Due Thursday, March 16 – Hard copy – by the start of class
Circle: 9:00 class
10:50 class
 Refer to graph information in the textbook (chapter 15), lecture notes, and climate change powerpoint files.
1. Sketch a graph that shows how CO2 has changed IN CONCENTRATION since 1958. Be sure to label both axes in
words and numbers. For the vertical axis (on the left), give values of CO2 concentration in parts per million.
2. How would the above graph look if CO2 had increased until 2000 and then leveled off? Sketch below (and label the
axes):
3. The figure below shows CO2 (top graph) and temperature (bottom graph) going back 400,000 years.
(a) Are CO2 concentrations and temperature correlated?
C02 & Temperature in Air Bubbles of Ice Cores
CO2 (ppm)
Why?
Temperature
(b) What was the highest CO2 concentration (in parts per
million) between 400,000 and the present?
Approx. ______________ ppm
When?_____________________
Years Before Present
4. The graph below shows temperature over the past 1000 years, specifically the “departure” of global temperature
from the average between 1961 and 1990. (So note: numbers on the Y axis are not actual temperatures but how much
higher or lower than the average (zero) line the temperature was)
(Departure from average 1961-1990)
Temperature
Describe in words the general pattern of change shown by this graph. Use words (like temperature, carbon dioxide,
year…) and explain broadly how things changed over time.
1000
Year
2000
5. Suppose the temperature became abnormally high from 1400-1500 and became unusually LOW after 1900. What
would the pattern on this graph look like? Make a blank graph below and draw in such a line. LABEL YOUR AXES.
(Assume that for all other time periods the temperature was right on the average baseline. )
6. What does the graph above show about approximate conditions around the year 1800? ________
(a)
(b)
(c)
(d)
(e)
Mean annual temperature was approximately minus (negative) 0.4o C
Mean annual temperature was 0.4o C lower than in 2000
Mean annual temperature was 0.4o C below the average between 1961 and 1990
CO2 levels were 4% lower than today
CO2 levels were 0.4% lower than today
7. Exactly what are stabilization wedges supposed to stabilize? See the article on Moodle, “Stabilization wedges”
and the case study in our textbook (pp.320-321: “When wedges do more than silver bullets”).
8. Explain each of the 15 potential carbon stabilization wedges. No numbers are needed. Don’t just copy but phrase
clearly. if you don’t understand, check explanations in the full article on Moodle and in other columns in the
source table.
Explanation of action to achieve a stabilization wedge
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