Experiments
Click here to go to the model. Please Note: The model in the videos below may look slightly different than the model linked here. Both models, however, function the same.
When you open the model, you will see that there are a lot of controls, reflecting the full range of choices we can make about our future energy consumption and geoengineering. There are also 15 pages of graphs that show the results of the model. Be sure to watch the video below that introduces you to the model before proceeding.
Video: Module 12 Intro to Model (7:09) (note the Model we use looks different from that in the videos but it works exactly the same and the results should be identical)
Practice Questions
Part A. Climate Control by Conservation and Renewable Energy
Be sure to watch the video below that shows how to do problems 1-3.
Video: Module 12 Questions 1 - 3 (2:01) (note the Model we use looks different from that in the videos but it works exactly the same and the results should be identical)
In this first experiment, we will use a combination of conservation of energy and greater reliance on renewable energy sources to limit climate change. Open the model and run it without making any changes — we’ll call this the “do nothing” scenario. You will see that we end up with 6.55°C of warming by the end of the model run in 2210, and if you look through the other graphs, you will see that the ocean pH drops to 7.68 (graph page 2). Looking at some of the other graphs, we see that this scenario results in a bit over 19 thousand dollars per person (graph page 14) in terms of the total costs (energy, conservation, climate damages, geoengineering), and an ending net economic output of about $460 trillion.
Now, change the model as described below:
Green colored sliders
Conserve upper limit: 30
Conserve growth rate: 0.1
Blue colored sliders
Renew upper limit: 85
Renew growth rate: 0.1
Then, run the model and answer the following questions by finding the values from the resulting graphs.
- What is the ending global temperature change that results from these changes (page 1)?
A) 4.2 °C
B) 3.6 °C
C) 2.1°C
D) 1.6°C
- What is the lowest pH of the oceans in this case (page 2)?
A) 8.06
B) 7.6
C) 8.20
D) 7.85
- What is the Total Cost Per Person (page 14)
A) 12.4
B) 8.2
C) 7.7
D) 2.4
Part B. Climate Control by Geoengineering
Now, we will try geoengineering alternatives, beginning with the direct removal of carbon — DCR. Be sure to watch the video below that shows how to get the answers to problems 4-7.
Video: Module 12 Questions 4-7 (3:08) (note the Model we use looks different from that in the videos but it works exactly the same and the results should be identical)
Make the following changes to the model:
Green colored sliders
Conserve upper limit: 1
Conserve growth rate: 0.1
Blue colored sliders
Renew upper limit: 20
Renew growth rate: 0.1
Red colored sliders
DCR switch: On
DCR start time: 2030
Target atm pCO2: 470
DCR cost decline rate: 0.02
DCR growth rate: 0.02
DCR init: 5
Once you’ve made these changes, run the model, and answer the following.
- What is the ending global temperature change that results from these changes (page 1)?
A) 4.2 °C
B) 2.6 °C
C) 1.97°C
D) 3.3°C
- What is the lowest pH of the oceans in this case (page 2)?
A) 8.06
B) 7.6
C) 8.20
D) 7.85
- What is the Total Cost Per Person (page 14)?
A) 11.2
B) 9.2
C) 6.7
D) 2.4
- Why do the human FFB emissions drop to 0 around the year 2195 (page 2)?
A) Our energy needs drop to 0 at this time
B) The economy has collapsed at this time
C) We run out of fossil fuels at this time
D) Must be a glitch in the model
Now we will try sulfate aerosol geoengineering — as before, the following video shows how to do this section.
Video: Module 12 Questions 8 - 9 (1:49) (note the Model we use looks different from that in the videos but it works exactly the same and the results should be identical)
Make the following changes to the model:
Green colored sliders
Conserve upper limit: 1
Conserve growth rate: 0.1
Blue colored sliders
Renew upper limit: 20
Renew growth rate: 0.1
Red colored sliders
DCR switch: Off
Orange colored sliders
Sulfate switch: On
Sulfate start time: 2030
Target T change: 2.0
Sulfate cost decline rate: 0.0
Once you’ve made these changes, run the model and answer the following.
- What is the lowest pH of the oceans in this case (page 2)?
A) 8.06
B) 7.6
C) 8.20
D) 7.58
- What is the Total Cost Per Person (page 14)?
A) 11.2
B) 9.3
C) 6.7
D) 2.4
Part C. Comparison
Now, let’s step back and consider what we have found here. Clearly, the “do-nothing” scenario is the worst in terms of temperature change and costs. But how about the other scenarios, each of which gets us to a temperature change of close to 2°C by the end of the model run — which is the best? The following video shows how to answer questions 10-12.
Video: Module 12 Questions 10 - 12 (3:46) (note the Model we use looks different from that in the videos but it works exactly the same and the results should be identical)
- Which of the three scenarios is the best from an economic standpoint?
A) Conservation + Renewables
B) DCR Geoengineering
C) Sulfate Geoengineering
- Which of the three scenarios is the best from an ocean pH standpoint?
A) Conservation + Renewables (by far)
B) DCR Geoengineering (by far)
C) Sulfate Geoengineering (by far)
D) A and B are about the same
- From an overall environmental and economic standpoint, which of the three scenarios is the best?
A) Conservation + Renewables
B) DCR Geoengineering
C) Sulfate Geoengineering
D) There are no clear winners