Heat-Trapping Gases

Notes from our reviewers

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• Teaching Tips
  Educator may need to explain what the blue and black lines on the graph represent (seasonal CO2 levels vs. average CO2 levels, respectively). Video could help to introduce and demonstrate the value of long-term scientific measurements. This could also launch a lesson on natural fluctuation or expand into a lesson of human influence on natural events. Could be used also with lessons on seasons or the carbon cycle. Other long-term data sets could also be introduced. Local or small scale long-term records could include ice records on lakes and ponds, temperature records, or phenological records, all contributing to an understanding of averages and changes over time.
• About the Science
  This short video clip features the landmark work of Charles Keeling, whose instruments, mounted on the top of Mauna Loa in Hawaii, documented the dramatic rise in CO2 concentration in the atmosphere, resulting in the oft-referenced Keeling Curve. Comments from expert scientist: Scientific strengths: - Explanation of annual variation in CO2 concentrations due to plants photosynthesizing and decomposing seasonally - Lists sources of CO2 - Explains importance of water vapor and the ratio increase of temperature to water vapor - Introduces a feedback loop - Excellent graphics
• About the Pedagogy
  Video is short and succinct and is as much a tribute to Keeling's work as it is a short explanation of the familiar graph. Text that accompanies the video provides some information about other greenhouse gases.
• Technical Details/Ease of Use
  Video length is 1:35 min.