In this lesson, students examine the issue of global warming. Firstthey identify some of the greenhouse gases that contribute to globalwarming -- in particular, carbon dioxide -- and the role humans play intheir production. Then students record their activities for an entiretwenty-four-hour period. Finally, in the second part of the lesson,students analyze their list of activities and calculate how much carbondioxide all the machines they use produce in one day.
- Identify the gases that contribute to global warming
- Discuss why the term "greenhouse effect" is an apt description for the phenomenon that causes global warming
- Determine the amount of carbon dioxide the average American produces in one day
- Two class periods
- Global Warming and the Greenhouse Effect QuickTime Video
- Snapshot of US Energy Use QuickTime Video
- Your Carbon Diet Shockwave Interactive
- Newsprint or chart paper
- Colored markers and pencils
Before the Lesson
- View and take notes on the videos Global Warming and the Greenhouse Effect and Snapshot of US Energy Use.
- Explore the Your Carbon Diet Web activity and familiarize yourself with the resources it contains. Use the site to help you answer the questions in this lesson plan and to anticipate student questions and problems.
- If necessary, reserve your school's computer lab for the second part of the lesson.
1. Write the following questions on the board, or create a worksheet ofthe questions for students to complete. Tell students that these arethe questions they will need to answer after they watch the videoGlobal Warming and the Greenhouse Effect.
- What are the four greenhouse gases, and where does each come from?
- Why is the production of greenhouse gases on the rise?
- Why is global warming linked to the greenhouse effect? How does the greenhouse effect work?
- Is the greenhouse effect always a bad thing? Explain your answer.
2. Show the video Global Warming and the Greenhouse Effect. You may need to show it several times in order for students to get all of the information they need. Have students jot down the answers to the questions.
Teaching Tip:If time is short, divide the class into groups and assign each group one question to answer. Then have groups share their answers with the class.
3. As a class, discuss the answers to the questions above.
4. Assign the following activity for homework: Ask students to keep track ofall of their daily activities for one twenty-four-hour period, that is,from the time they wake up tomorrow morning until the time they wake upthe following day. They should include how much time they spent on eachactivity or distance traveled. Have them bring this list to class.
Teaching Tip:You may wish to brainstorm a list of likely activities with studentsbefore assigning the homework (for example, used a blow dryer - tenminutes; showered - 15 minutes; made toast - two minutes; drove a carthree miles to school; walked three blocks to school; watched television- 3 hours ...). In this way, students will know what kinds of items tolist and can get a head start on the assignment.
Part II: How much carbon dioxide do you produce in a day?
5. Ask students to share their list of daily activities with each other. Thenask them which activities use electricity or fossil fuels. Have themplace a check mark next to all of the activities that use energy.
6. Review the relationship between energy usage and the production ofcarbon dioxide -- the main greenhouse gas. Ask students if they thinktheir activities produced a lot of carbon dioxide. Tell them that theyare going to try and figure out exactly how much carbon dioxide theyused to run appliances and machinery in one day.
7. Show the video Snapshot of US Energy Use. This video has some important statistics that students will need inorder to perform their calculations. (Students may need to view thisvideo more than once to get all of the information.) Some importantnumbers to jot down include the following:
- One kilowatt hour of energy produces 1/2 pound of carbon.
- The average toaster uses 39 kilowatt hours of energy per year.
- Each pound of carbon combines with oxygen to make 4 pounds of carbon dioxide.
- One kilogram = 2.2 pounds.
- The average person in the United States produces 20,000 tons of carbon dioxide per year.
8. Using the information from the video and the Web activity, Your Carbon Diet, have studentscalculate how much carbon dioxide their daily activities produce. The activity provides additional energy consumption information for other appliances and modes of transportation.
Teaching Tip:If your classroom doesn't have Internet access, you will need to either schedule time in your school's computer lab or visit the Web site yourself and prepare a one-page summary of the energy usage numbers for your students.
9. After students complete this part of the activity, have them share their results with the class. Discuss what surprised them about their "carbon diet."
10. Add up the total amount of carbon dioxide produced by the class. Discuss the results.
11. If time permits, determine how much carbon dioxide the entire school produces in one day, based on the class data. Discuss the results.
12. As a final assignment, let students choose one of the following:
- Write an article about energy use and carbon dioxide for the school newspaper.
- Develop a short presentation for a local elementary school class about energy use and carbon dioxide.
- Make a pamphlet that informs the public about ways to reduce energy usage and greenhouse gases.
It is very important that students feel they can make a positivecontribution to the environment. Following this activity, students canresearch alternative energy sources that do not contribute to global warming.