Directions 1. Have students recall ideas about the relationship between CO2 and temperature. Remind students that in the previous activity they examined the mechanism called the “greenhouse effect.” Ask volunteers to explain in their own words what the greenhouse effect is. Use student ideas to construct a group explanation for the greenhouse effect. Listen for and highlight key ideas: short-wave radiation entering Earth’s atmosphere passes through greenhouse gasses (GHGs); long-wave radiation is emitted into the atmosphere after it interacts with the Earth’s surface; long-wave radiation interacts with GHGs which causes an increase in temperature. 2. Revisit the four Earth systems. Give each student one copy of 3.3 Explaining Relationships Between Earth Systems Worksheet. Draw students’ attention to the four phenomena on page 1 of the worksheet. Ask the class for any ideas about how these four phenomena might be related. Remind students that the scientific community is concerned about the rising concentrations of CO2 and what this means for the global atmospheric / oceanic temperatures, and how this might change the climate (which relates to the extents of the Arctic ice and the sea levels). This activity will help students begin unpacking connections between these variables. 3. Have students complete the worksheet by drawing arrows to indicate relationships between the phenomena. Give students 3-5 minutes to draw their arrows on the concept map on page 2 of the worksheet. When they have finished, ask them to compare their arrows with a neighbor and discuss differences. Ask the pairs to raise their hands if their arrows and explanations matched their partners. Ask the pair to raise their hands if their arrows and explanations differed from their partners. Ask them to explain how they differed. 4. Construct a group explanation for the relationship between Earth systems. In a location where all students can see, replicate the four boxes on a white board or poster paper. Using the students’ ideas as a starting place, ask them where the arrows should go and which explanations go with each arrow. If students disagree, ask them to explain their ideas. Point out to the students that the goal of this conversation is to build consensus around where the arrows and explanations go. At this point, they will have evidence that atmospheric CO2 causes and increase in temperature. Have them use the other explanations presented in the worksheet to piece together their explanation. Use the question “What is causing what?” as a guiding question during this group conversation. 5. Have students construct an individual written explanation for the relationships. Tell students to use their own concept map (arrows and boxes) and the class concept map to construct a written explanation for the relationship between the four Earth systems. Give students 5-10 minutes to construct a written explanation on their worksheet. Remind students to use evidence (from what they know of the greenhouse effect and the explanations on the concept map) in their explanations. 6. Have students share their explanations in groups. Divide students into groups of four. Tell them that they should compare their explanations in groups with the goal of reaching consensus. The question their explanations should be answering is “What is causing these systems to change?” Use this conversation as formative assessment to determine if your students are able to reach consensus about their explanations. 7. Have a discussion to introduce the Learning Tracking Tool for this activity. Pass out a Learning Tracking Tool for Human Energy Systems to each student. Explain that students will add to the tool after activities to keep track of what they have figured out that will help them to answer the unit driving question. Discuss goals for this lesson. Have students write the activity name in the first column, "Questions for this Lesson." Have a class discussion about what students figured out during the activity that will help them in answering the lesson driving questions: What causes the annual cycle: CO2 concentrations in Hawaii to go down every summer and up every winter? What causes the long-term trend: CO2 concentrations to go up every year? How can we predict what will happen to CO2 concentrations in the future? When you come to consensus as a class, have students record the answer in the second column of the tool. Have a class discussion about what students are wondering now that will help them move towards answering the unit driving question. Have students record the questions in the third column of the tool. Have students keep their Learning Tracking Tool for future activities. Example Learning Tracking Tool Activity What We Figured Out What We are Asking Now 3.3 Explaining Relationships Between Earth Systems CO2 is the driver: Changes in atmospheric CO2 cause changes in Arctic sea ice, global temperature, and sea level. What causes changes in CO2 concentrations and how can we predict those changes?
