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
Ø 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?
Why?
(b) What was the highest CO2 concentration (in parts per million) between 400,000 and the present?
Approx. ______ppm
When?______
C02 & Temperature in Air Bubbles of Ice Cores
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)
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.
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) Mean annual temperature was approximately minus (negative) 0.4o C
(b) Mean annual temperature was 0.4o C lower than in 2000
(c) Mean annual temperature was 0.4o C below the average between 1961 and 1990
(d) CO2 levels were 4% lower than today
(e) 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 wedge1
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