Click here to go to the model [1]. 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.
Be sure to watch the video below that shows how to do problems 1-3.
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.
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.
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.
Now we will try sulfate aerosol geoengineering — as before, the following video shows how to do this section.
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.
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.