Educator Resources

Overview

In this Click & Learn, students explore factors that contribute to patterns seen in the Keeling Curve: a continuous record of atmospheric carbon dioxide starting in 1958, as measured at the Mauna Loa Observatory in Hawaii. The Click & Learn includes the actual data from Mauna Loa.

The first tab, "Natural Processes," focuses on the processes of respiration and photosynthesis. Students adjust parameters in a model of these processes to match the model with data from Mauna Loa. (In order to focus on natural processes, the data were adjusted to "subtract" the human contribution. This was done by removing the annual increase and assuming a steady-state model in which photosynthesis and respiration are balanced.)

The second tab, "Human Contribution," shows the original data from Mauna Loa. Students adjust a human contribution parameter in the model to match the Keeling curve.

Additional information related to pedagogy and implementation can be found on this resource's webpage, including suggested audience, estimated time, and curriculum connections.

Key Concepts

  • The concentration of carbon dioxide in the atmosphere can be directly measured, and there is a continuous record of carbon dioxide measurements going back to 1958.
  • The amount of carbon dioxide in the atmosphere responds to natural processes, which can add and remove carbon dioxide from the atmosphere.
  • The natural processes of photosynthesis and respiration cannot account for the overall rise in atmospheric carbon dioxide since 1958.
  • Human activities release carbon dioxide into the atmosphere and have significantly increased overall carbon dioxide levels.

Student Learning Targets

Use a simulator to adjust the parameters in a model to match observed carbon dioxide levels.

References

Keeling, C. D., S. C. Piper, R. B. Bacastow, M. Wahlen, T. P. Whorf, M. Heimann, and H. A. Meijer. "Exchanges of atmospheric carbon dioxide and 13carbon dioxide with the terrestrial biosphere and oceans from 1978 to 2000." I. Global Aspects. UC San Diego: Library – Scripps Digital Collection (2001). https://escholarship.org/uc/item/09v319r9.