Is it a Greenhouse Gas?

Introduction
Students will collect, read, analyze and interpret data on different gases to determine if there is evidence to support the claim that the gas is a greenhouse gas. Then they will develop a written paragraph using evidence to support their determination or claim.

Credits
Activity developed by Tracy Ziettlow UCAR AirWaterGas Teacher-in-Residence woith support from science advisors Shannon Capps, Geoff Tyndall and John Orlando.

Data from: Absorption by atmospheric gases of incoming and outgoing radiation, by Sara Harris, University of British Columbia

Grade level: 9-12

Time Required
This lesson is best taught after teaching the Trapping Heat with Carbon Dioxide lab (about 50 minutes)

1-2 periods for data collection, analysis of data and written explanation development

Learning Goal
Students will learn to collect, read, analyze and interpret data to create a claim, evidence, reasoning and explanation pertaining to a greenhouse gases.

Lesson Format
Calculating, readings, data collection, writing

Standards (Next Generation Science Standards)

  • HS-ESS2-2  Analyze geoscience data to make the claim that one change to Earth’s surface can create feedbacks that cause changes to other Earth systems.
  • ESS2.D Weather and Climate: The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space.
  • PS4.B Electromagnetic Radiation

Materials

Preparation

  • Print wavelength absorption graphs, student information sheets, student data collection sheets, write up, and the article, these can be reused for multiple classes. Laminate if you want to re-use. If re-using these documents, have students use an expo marker to calculate the molecule vibrational modes column on student data collection sheet.

Directions

Note: You may wish to do this activity after students have done the Trapping Heat with Carbon Dioxide lab.

  1. Provide each pair of students with the Wavelength Graphs, the Is It a Greenhouse Gas? Student Data Collection Table, and the Is It a Greenhouse Gas? Student Information Sheet.
  2. The first two columns of the Is It a Greenhouse Gas? Student Data Collection Table require students to work with pre-made graphs. Have students locate the peak of each spike for each of the three gases absorption profiles.
    • Introduce students to the graphs by looking at  the graph for CO2 as a class. Notice there are 3 peaks.  The highest point on the first peak (from zero) is at a wavelength of 2.7 microns (on x axis) and .2 absorption (on y axis).  Change the absorption to a percent (.2 x 100 = 20%).  The data chart has a line/space for the number of expected peaks for each gas.
  3. On the Is It a Greenhouse Gas? Student Information Sheet, the “Number of Vibrational Modes” column on page 2 will need to be calculated by the students using the formulas beneath the table. Direct teacher guidance may be needed.
  4. The remaining columns contain information provided on the Is It a Greenhouse Gas? Student Information Sheet. (Note: If you did the Trapping Heat with Carbon Dioxide lab, students can use data from that too.)
  5. The last column is where students decide whether or not there is evidence that this gas acts as a greenhouse gas.
  6. After completing Is It a Greenhouse Gas? Student Data Collection Table have the students read the article, “What Are Greenhouse Gases and How Do They Warm the Earth?
  7. Hand out the Is It a Greenhouse Gas? Write Up Sheet. Have students consider which greenhouse gas is causing the most change in our climate, summarize their conclusion, and back it up with evidence and reasoning.

Assessment
Students will be assessed on the completion of their data table and their final written explanation.

Background information
Greenhouse Gases: Even though greenhouse gases (such as carbon dioxide, methane and nitrous oxide) make up less than 1% of the atmosphere they have a major impact. Greenhouse gases trap heat in the atmosphere through a process called the greenhouse effect. Having some greenhouse gases in the atmosphere is natural. Their heat-trapping abilities keep Earth from being uncomfortably cold. However, the amount of greenhouse gases in our atmosphere has increased over the past 150 years as people burned fossil fuels and changed landscapes, decreasing the amount of forests, which naturally take the greenhouse gas carbon dioxide our of the air as the plants photosynthesize.

https://scied.ucar.edu/shortcontent/what-impacts-climate-earth

For more information: http://scied.ucar.edu/longcontent/greenhouse-effect

Extensions
Advanced students may extend their knowledge by researching atmospheric radiation and chemistry.