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Human Energy Systems | Activity 4.1

Activity 4.1: Activity 4.1: Your Ideas About the Keeling Curve (30 min)

Now that students have evidence that increasing CO2 levels are driving global change, they share their ideas about why CO2 levels are increasing in the atmosphere by interpreting data in the Keeling Curve.

Materials You Provide

Resources Provided


Print one copy of the 4.1 Your Ideas About the Keeling Curve Worksheet per student. Print one copy of Big Idea Probe: What Would Happen if We Cut Fossil Fuel Use in Half? per student if you are using it. Prepare a computer with an Internet connection to view the videos online.


1. Introduce the Lesson and Activity.

Remind students that in the previous activities and lessons they used evidence to construct explanations about how increasing levels of CO2 in the atmosphere is the driver of other changes in global systems. In this Lesson, they will examine more closely why and how CO2 levels are increasing. Before we do that, though, we will share our initial ideas about one specific Earth system: the Keeling Curve.


  • Formative Assessment: Use the ideas students share in this first lesson as a “baseline” for where their understanding is at this point. Even with the jigsaw activity in Lesson 2, students may still be “warming up” to the data presented in this graph. Use this activity to determine where their ideas are at this point in the unit. They may still be uncertain about what the two different lines in the graph mean and represent, and what causes the patterns.
  • Check to see if students make the connection between the circulation video and the “generalizability” columns in their Evidence Based Arguments Tool. At this point, they should be able to recognize that due to the circulation of atmospheric molecules in the Northern Hemisphere, that the data collected in Hawaii is generalizable to the entire Northern Hemisphere. If this is not clear, you may want to revisit the “Pumphandle” video from Lesson 2 and compare the CO2 data sets from the northern and southern hemispheres to show how they differ.


Remind students that in the worksheet they are recording their initial ideas. They want to provide as much detail as possible so that when they revisit their ideas later they can see how their ideas changed.

Extending the Learning

The Keeling Curve is often mentioned in the news and other media. Have students bring in articles that mention how many parts per million of carbon dioxide are currently in the atmosphere.