Directions 1. Introduce the Very, Very Simple Climate model. Prepare a computer with a projector to display the Very, Very Simple Climate model at http://scied.ucar.edu/simple-climate-model Tell students that in this model, average global temperature is determined entirely by the amount of CO2 in the atmosphere and its effect on temperature (the greenhouse effect). The model is based on the simple mathematical relationship between atmospheric CO2 concentration and average global temperature, which states that temperature rises about 3°C each time atmospheric CO2 Show students how to change the CO2 emissions by moving the slider and demonstrate how to run the model by clicking “step forward” or “play” at the top. 2. Use the Worksheet to work through the first scenario. Pass out the 6.1 Using Models to Predict Future Conditions Worksheet and read scenario #1 out loud to the class. Ask students to predict what will happen to atmospheric CO2 concentrations and temperature if CO2 emissions remain constant at 10 GtC/yr by drawing the corresponding lines on their graph for question 1. Have a few students to share their predictions and reasoning with the class. You may wish to have them draw their predictions on the board. After making predictions students should run the simulation and answer questions 3-7 with a partner. Discuss the results of scenario #1 with the class. It is important that students see that even when CO2 emissions stay constant, the concentration of atmospheric CO2 continues to increase and thus temperature continues to increase. This is surprising for many students because they often fail to distinguish between emissions (the CO2 flux) and atmospheric CO2 (the pool). > 3. Students complete scenario #2 on the worksheet. Read scenario #2 out loud to the class. Ask students to predict what will happen to atmospheric CO2 concentrations and temperature if CO2 emissions continue to increase as shown on the graph. They should draw lines for CO2 concentration and temperature on the graph to show their predictions. Have a few students to share their predictions and reasoning with the class. You may wish to have them draw their predictions on the board. After making predictions students should run the simulation and answer questions 10-13 with a partner. Discuss the results of scenario #2 with the class. Students should see that increasing CO2 emissions causes atmospheric CO2 and global temperatures to increase at a faster rate and reach higher maximums by the end of the century than in scenario #1. 4. Students develop a strategy for limiting climate change using the model. Read the directions to the “Limiting climate change” section of the worksheet aloud. Check to be sure that students are able to find the box “Show Warming Limit Targets” on the model in order to get the lines for the pre-industrial average temperature and 2°C recommended warming limit to appear on the graph. Remind students that drastic reductions in CO2 emissions over a short period of time would be nearly impossible to accomplish given our current global society. In addition, remind students that the graph only shows predicted temperatures up to the year 2100, but that we wouldn’t want the temperature to increase more than 2°C even after that. They should keep in mind that the goal is to get the temperature to begin to level off well before the end of the century. Have students complete question 14 with a partner. They should indicate their results on the graph and explain their scenario in words. 5. Students share their scenarios (emissions settings and results) with the class. Ask a few students to share their strategies for limiting warming to 2°C. It is important that students realize that CO2 emissions must decrease if we hope to keep global temperature increases below the 2°C recommended warming limit. Discuss as a class how feasible their settings were. Check to make sure that they realize that drastic short-term reductions in CO2 emissions or future emissions that are near zero would be virtually impossible given our current reliance on fossil fuels for everyday activities. 6. Have students complete an exit ticket Conclusions: How much will humans need to reduce CO2 emissions to stabilize the Earth’s climate? Predictions: What could we do to change CO2 emissions? On a sheet of paper or a sticky note, have students individually answer the exit ticket questions. Depending on time, you may have students answer both questions, assign students to answer a particular question, or let students choose one question to answer. Collect and review the answers. The conclusions question will provide you with information about what your students are taking away from the activity. Student answers to the conclusions question can be used on the Driving Questions Board (if you are using one). The predictions question allows students to begin thinking about the next activity and allows you to assess their current ideas as you prepare for the next activity. Student answers to the predictions question can be used as a lead into the next activity.