In this lab activity, students use a chemical indicator (bromothymol blue) to detect the presence of carbon dioxide in animal and plant respiration and in the burning of fossil fuels and its absence in the products of plant photosynthesis. After completing the five parts of this activity, students compare the colors of the chemical indicator in each part and interpret the results in terms of the qualitative importance of carbon sinks and sources.

This is an interactive visualization of the Carbon Cycle, through short-term and long-term processes.

NASA produced white-board animation video explains key concepts about the role and source of carbon dioxide as a greenhouse gas.

Here students use data from the NOAA carbon dioxide monitoring sites, such as Mauna Loa, to graph the Keeling Curve for themselves on large sheets of paper. Each group graphs one year, and the graphs are joined at the end to reveal the overall upward trend. The explanation describes the carbon cycle and how human activities are leading to the overall trend of rising carbon dioxide.