Lesson Plan: First Steps Toward Healing the Ozone

Subject:

Environmental Science

Grade Level:

9-12

Lesson Duration:

• Four or five 45-minute class periods
• If you have less time, consider skipping the patent observation process and jump right into the NASA data. It is also possible to complete only the video/timeline part of the lesson.

Essential Questions:

• How do human actions affect the environment?
• How can data be used to leverage action to solve political, social and economic problems?

Lesson Objectives:

Students will:

• Analyze data to determine trends in atmospheric ozone from 1979 to today.
• Establish a timeline of events related to ozone depletion and repair.
• Communicate to a wide audience the relationship between data collected and societal actions.

Materials: 

• Retro Report video “Healing the Ozone: First Steps Toward Success” (Transcript)
• Student Activity handout
• Ozone Watch Maps | NASA
• Advanced Global and Atmospheric Gases Experiment (AGAGE) | M.I.T.
• U.S. Patent for Refrigerating Apparatus
• Climate Change Timeline | USA Today

Procedure:

Day 1:

1. Do Now: Present students with the image from US Patent 1910996A, but remove the text that identifies it (this has been done on the activity sheet). Have students observe, reflect and question on the Student Activity handout. The goal is for students to think about which components of this device may be affecting the environment.
   1. Information on the “Observe, Reflect, Question” protocol can be found on the Library of Congress website.
   2. If your students are familiar with “See, Think, Wonder,” that protocol can be substituted.
2. Once students have individually conducted the Observe, Reflect, Question protocol, ask them to review their thoughts to answer the question, “What is represented by this diagram?” Students can work with a partner.
3. Have students share their ideas with the class. If no student pair comes up with a refrigerator, consider giving additional hints. Consider drawing student attention to feature 21. Ask what that structure might be for (this is the compressor for the refrigerant). Depending on the level of your students, you might also consider supplying them with excerpts from the text on the patent application. For younger students, you can start labeling some of the components to see if that helps guide them to an answer.
4. Once students have identified this image as a refrigerator, have the class brainstorm a list of effects this invention had on society (this can be recorded on the Student Activity handout). Remind students that this list can contain both positive and negative effects.
   1. Possible responses could include: Prolonged food storage, increased release of refrigerants into atmosphere, allowed for food transport, technology was adapted for air conditioning
   2. Keep this list posted, so students can add to it throughout the remaining lessons
5. Transition by explaining that you are going to work on adding to/specifying entries on this initial class list (effects of this invention on society).
6. Introduce students to the NASA Ozone Watch Maps by exploring the June 2023 map. As a class, watch the June 2023 animation (preferably the 1920×1080) and have students record their observations on the Student Activity handout.
   1. During this initial exploration, be sure to point out the legend for the map. Have students note changes in color as well as the location of those changes. Students can also look at the maps created for each individual day of June 2023.
7. Have students form small groups of two to four. Once they are comfortable with reading the maps, ask them: “How has the amount of ozone in the atmosphere over Antarctica changed since 1979?”
   1. Students should explore the data on the NASA Ozone Watch website and decide how best to answer this question. Students should outline their plan on the Student Activity handout.
   2. Students will be sharing their answers to this question during a Gallery Walk on day 2. As they make a plan for how they will answer the question, the teacher may need to share some examples of the types of data choices students can use.
   3. It won’t be feasible for students to incorporate monthly data over the course of 4+ decades. Students may choose something like January data from every 5 years since 1979 or data from 3 months per year for every 10 years.
8. Closure: Have groups share out a status update for their group.Day 2:
9. Student groups should continue working with NASA Ozone Watch Maps to answer “How has the amount of ozone in the atmosphere over Antarctica changed since 1979?”
   1. Students should incorporate specific data from the NASA page and are encouraged to include screenshots of maps to help others visualize the data.
10. Once all of the groups have answered the question, have a gallery walk. One student from each group should stay at their computer to show the other groups what they have found. As the students navigate around the room they should take notes on what the other groups have found.
    1. Give students about 3 minutes at each table before alerting them to switch to the next group.
    2. At several points throughout the gallery walk, have the students take turns as the person at the computer.
    3. After the allotted amount of time (will vary depending on the number of groups), have students return to their original group and discuss their findings. This would be an opportunity for any student who missed a group to catch up. Students should discuss whether their conclusion needs to be edited based on these new observations.
11. Exit ticket: Each group should record their final conclusion on a slip of paper and submit it at the end of class.Day 3:
12. The goal of today’s data observations is to link patterns in CFCs to patterns in ozone.
    1. Do Now: Have a Chlorofluorocarbon (CFC) graph from the Advanced Global and Atmospheric Gases Experiment (AGAGE) site laid out for each group. Have the groups report to their stations and observe the graph. Each group should record the major trends on a sticky note.
13. Consider printing the graph for CFC-113, CFC-114, CFC-115, CFC-11, CFC-12, CFC-13 depending on the number of groups.
    1. “Global” graphs will likely be easier for students to interpret. (Graphs labeled PDF have data from multiple monitoring stations as well as included error bars; the Global graphs aggregate the data into three distinct areas.). For an advanced group, consider using the PDF Download.
    2. If you need to eliminate any of the graphs due to the number of groups you have in a class, consider that different CFCs show different trends. Select CFC’s from each of the groups below:
    3. Linear increase: CFC-13
    4. Logistic growth: CFC-11, CFC-12, CFC-113
    5. Logistic decline: CFC-114
    6. Exponential growth: CFC-115
14. Once each group has filled in their sticky note, have them move around the room and record the other group’s findings on their student activity sheet.
15. Have students return to their groups and discuss how the trends in atmospheric CFC relate to the trends in atmospheric ozone. They should record their observations on the Student Activity handout.
16. Have each group share its observations.
17. Return to your class list of the effects of refrigeration from day 1, and prompt students to add the relationship between CFCs and the ozone layer.
18. Transition to the Retro Report video “Healing the Ozone: First Steps Toward Success” by explaining that students will now observe what was happening politically/socially/economically during the time these changes in CFC and ozone were occurring.
19. Have students extract information from the Retro Report video to establish a timeline of events related to ozone depletion and repair. You can also provide students with the transcript if they need to revisit any information after the video. Events they record might include:
    1. 1930s: CFCs revolutionized consumer goods (hairspray, bug spray, refrigerators)
    2. 1974: Molina and Roland hypothesized that CFCs migrated to the upper atmosphere and destroyed ozone
    3. “All in the Family” dedicates episode to ozone
    4. Reagan administration: started talking about CFCs
    5. Secretary of the Interior Donald P. Hodel suggested that wearing hats, sunglasses and sunscreen could be effective alternatives to an international agreement to remedy ozone depletion.
    6. 1980s: Concentration of ozone depleting gases was going up 5 percent to 10 percent each year
    7. 1985: British Antarctic Survey discovered the ozone hole
    8. 1986: Scientists went to Antarctica to determine what was causing the hole
    9. 1987: U.N. organizes a summit in Montreal
    10. 1990s: Montreal Protocol was in place
    11. Wealthy countries had to develop alternatives and drive down price
    12. Less wealthy countries had to do the same 10 years later
    13. 2023: Scientists say that ozone layer is healing
    14. 2050-60: Scientists say recovery of the ozone layer may be possible
20. Closure: Have students return to their groups to compare events that they each recorded. At this time they can fact-check any of their notes against the video transcript.Day 4:
21. Do Now: Why is the story of the ozone layer relevant to conversations surrounding climate change that are happening today?
    1. Students can answer this question on the Student Activity Sheet
    2. Once students record their responses, discuss this as a class. Be sure to highlight the stepwise approach that was taken and the fact that progress was made in addressing environmental issues with the ozone layer. It is easy to become discouraged when confronted with large problems such as climate change, but the scientific process taken to address ozone depletion had a positive outcome. Be sure to elevate this with your students.
22. Have students read through the USA Today timeline of climate change related events noting any similarities and differences they see compared to the ozone timelines created yesterday.
23. Have a class discussion about the question, “Do you predict the climate change issue will have a conclusion like the ozone layer issue? Why or why not?”
    1. Prior to starting the discussion give students a chance to brainstorm their response to this question on the Student Activity sheet.
    2. During the discussion prompt students to provide evidence from the Retro Report video, NASA data, M.I.T. data, and USA Today timeline.
24. Exit Ticket: Based on the class discussion, would you change your response to the question “Do you predict the climate change issue will have a conclusion like the ozone layer issue? Why or why not?” Explain why your thinking did or did not change.

About the Author:

Jacqueline Katz has taught Biology, Chemistry and Environmental Science in New Jersey since 2012. She was an Albert Einstein Distinguished Educator Fellow at the Library of Congress during the 2022-23 school year.

Standards

Next Generation Science Standards

• MS-PS1-1: Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms. 
• MS-PS-2&3: Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it. 
• HS-PS1-3: The structure and interactions of matter at the bulk scale are determined by electrical forces within and between atoms. 
• Science and Engineering Practices
  • Analyzing & interpreting data
  • Engaging in argument from evidence
  • Obtaining, evaluating and communicating information

College, Career, and Civic Life (C3) Framework for Social Studies

• D3.1.6-8. Gather relevant information from multiple sources while using the origin, authority, structure, context, and corroborative value of the sources to guide selection
• D3.3.6-8. Identify evidence that draws information from multiple sources to support claims, noting evidentiary limitations
• D4.1.6-8. Construct arguments using claims and evidence from multiple sources, while acknowledging the strengths and limitations of the arguments.
• D4.1.9-12. Construct arguments using precise and knowledgeable claims, with evidence from multiple sources, while acknowledging counterclaims and evidentiary weaknesses.