I used this unit to launch the content of the Climate Science class. It got us situated in how to think and talk about complex systems, which we drew upon throughout the rest of the course. The radio piece about fires and their impact on ice albedo was something we came back to multiple times in the course, in subsequent discussions of Earth's radiative balance, aerosols, short-lived climate forcers, and other topics.
We completed Unit 2 immediately after Unit 1. We started class with a discussion about the functional form of response of variables versus time, to introduce the quantitative nature of the system diagrams, and about the fact that the components of the systems diagram that are buried or not included depend on the perspective of the person drawing it, so that the perspective of the creator of the diagram matters. This introduced a more critical approach to the problem. The students drew diagrams, did a gallery walk, and revised their diagrams. The homework assignment was highly successful, with students coming up with various interesting local systems. The system described by the largest number of students was the campus post office. After Unit 2, nearly every student automatically drew a systems diagram whenever we were discussing a complex system.
We waited too long to get to Unit 3, for a variety of reasons, but we used it as a quantitative introduction to modeling just after embarking on a class project to use EdGCM (more info)
, a Global Circulation Model that allowed students to engage with a research-grade climate model. We started by looking for an inflow-reservoir-outflow component in the system diagram that they drew in Unit 2 (after reforming the groups and handing back a printout of their submitted Unit 2 model). When asked to think about equilibrium, and to estimate values for the reservoirs and fluxes, they were comfortable with the former and struggled with the latter. They then used the STELLA models in the ISEE Viewer, which students downloaded onto their own laptops at the beginning of class. This gave the students a chance to see how adjustments to reservoirs and fluxes could dramatically affect system behavior. They were able to extrapolate this experience to the individual calculations that occur in the GCM, which was a nice way to give them a feel for what was happening "behind the scenes" in it. They were interested in exploring the equations behind the exercises that were provided, and found the illustrations to be helpful. We needed to do another activity at the end of the class period, meaning we had only 35 minutes for the unit, so students finished Experiment 2 and did the homework on their own after class.
Unit 4 was done a week after Unit 3, based on the specifics of our course schedule. Students were ready to go, and we discussed the real-world examples quickly, with a longer discussion about the fact that reinforcing feedbacks can be "friend" or "enemy" — that it is context-specific. The students made good progress through the investigation of feedbacks, completing most of the second experiment before we had to stop to move on to another scheduled activity. They completed the work and the homework after class.
We did a project related to The Carbon Cycle right before working on Unit 5, so we used this as the example in Unit 5. As a result, we were well primed, and dove right into looking at this system and thinking about what could be represented quantitatively. The exercise went well once I gave them a specific outline to follow: step 1: Think about numbers: reservoirs and fluxes. Sketch graphs on half-sheets of paper. Must include 1 flux and 1–2 reservoirs, where at least one must change with time; step 2: Attach collage, including carbon cycle, to whiteboard; step 3: Gallery walk, looking at each others', and then adjusting their own if needed. They had good discussions, and they found it interesting to use content knowledge to flesh out the connections in the diagram. The discussion about how to learn what they needed to learn was engaged, and they had good ideas. The homework went well, and their responses showed a strong understanding of the need to bring in resources from a variety of sources to understand something as complex as The Carbon Cycle.
We did this activity on the second-to-last day of class, and used it as described: to assemble the types of concepts that we had discussed throughout the term. Students had already done the summative assessment for the module before this class; it was done as homework and was due this class period. For this exercise, I created a list of questions, based on the number of students in the class, and got them set up in initial pairs. I introduced the exercise to them as a "Climate Science Speed Dating" game, and they got the concept well, but were not fast enough in the first round. In subsequent rounds of discussion, I ended up choreographing their interactions more closely, calling time when they needed to switch which question they were discussing at 1.5 and 3 minutes, and telling them to switch to discussing how to link their topics. We went through three rounds of questions. This activity was a fun way to finish the term. The discussion afterward was a bit more challenging, as there were not specific topics that stood out as especially problematic to link.