The following adaptable classroom activities suggest various approaches for introducing and/or extending learning on global warming.
1. Imagining the Effects of Global Warming
While the idea of global warming is still controversial in the U.S. (see NOW's Debating Global Warming at http://www.pbs.org/now/science/climatedebate.html), many around the world believe that global warming is a serious threat. (See International Perspectives on Global Warming at http://www.pbs.org/now/science/climatemediaint.html). Scientist John Harte is one who is greatly concerned about global warming, based on his years of research on this issue. In a NOW interview with Harte on 9/17/04 available at http://www.pbs.org/now/science/climateqanda.html, he talks about the everyday effects global warming could have on America and its people. An excerpt from the interview is available as a classroom handout for use with students. Read the interview excerpt and use it as a starting point for discussing the effects that global warming could have on the U.S.
After students have finished reading the interview excerpt, ask them to list, as a class, the effects that global warming could have on the following areas:
Their list should be based upon what was learned from reading the Harte interview excerpt as well as their own hypothesis of what might happen. As a follow up to this exercise, students could examine whether or not Americans should be more informed and concerned about global warming and other environmental issues, as well as what citizens can do to find out about the latest research findings related to global warming.
- agriculture/food supply
- overall weather and weather patterns
- water levels and supplies
- other effects of global warming
2. Hybrid Vehicles: An Important Step Toward Addressing Global Warming?
Under California's Pavely Law, all new cars and light trucks in California will have to have reduced global warming emissions by 2009. This regulation has caused much controversy between the state and automobile manufacturers, spurning lawsuits and opposition. Using the Handout: Global Warming and Fossil Fuels Quiz, (quiz questions and answers appear below for teachers), ask students to use prior knowledge to make educated guesses and estimates about the answers to the quiz.
Global Warming and Fossil Fuels Quiz and Key (teacher copy)
1. The primary greenhouse gas produced by engines powered by fossil fuels is called ________ ___________. (answer: carbon dioxide)
2. Personal vehicles constitute ____% of all U.S. oil consumption (answer: 40%)
3. Personal vehicles generate ____% of all U.S. carbon emissions (answer: 19%)
4. Carbon emissions from personal vehicles account for ___% of all air pollution in the U.S. (answer: 33%)
5. Only about ____% of the energy in the fuel used in the average car is used to move the vehicle down the road. The remaining fossil fuel energy is lost. (answer: 15%)
6. The U.S. imports _____% of all the oil it uses. (answer: 54%)
7. During the past 200 years, over _____% of all world oil reserves have been used. If the current rate of use continues, there is only about a ____ year supply left. (answers: 50%, 40 year)
8. By using hybrid vehicles that combine combustion engines with electric motors, consumers can ________ their gas mileage while decreasing emissions by _____%. (answers: double, 50%)
Once guesstimates have been made, utilize the "Overview" section of the NOW resource Road Work Ahead (http://www.pbs.org/now/science/autoemissions.html) to have students find the exact answers to the questions above. This could be done as a class, in small groups, pairs, or individually. Close by asking students to form an opinion about the Pavely Law that regulates emissions standards for vehicles in California and why it should or should not be upheld based upon what they have learned from the quiz.
To extend the activity, have students create a flow chart describing how cars pollute using this excerpted paragraph from Road Work Ahead:
Transportation involves the combustion of fossil fuels to produce energy translated into motion. Pollution is created from incomplete carbon reactions, unburned hydrocarbons or other elements present in the fuel or air during combustion. These processes produce pollutants of various species, including carbon monoxide, soot, various gaseous and liquid vapour hydrocarbons, oxides of sulphur and nitrogen, sulphate and nitrate particulates, ash and lead. These primary pollutants can, in turn, react in the atmosphere to form ozone, secondary particulates, and other damaging secondary pollutants. Combustion also produces carbon dioxide, the primary greenhouse gas. (United Nations Department of Economic and Social Affairs, Division for Sustainable Development)
Another extension using the Road Work Ahead resource would be to have students access the link describing "how hybrids work" to introduce them to hybrid vehicles and how utilization of these types of vehicles by consumers might curb global warming by reducing the number of greenhouse gasses released into the atmosphere.
3. Exploring Alternative Energy Sources
Many scientists who have studied global warming have concluded that the carbon dioxide released from burning fossil fuels like oil and coal causes significant damage to the earth's atmosphere. For those who believe the effects of global warming are a threat, the development and use of alternative energy sources provides one way to address the problems associated with global warming. To focus students on the significance of why we should begin developing and using other types of energy, pose the following questions:
Next, work as a class to create a list of alternative, renewable energy sources that could be used to meet some of America's energy needs. Using NOW's Wind Power Primer (http://www.pbs.org/now/science/wind.html) as a resource, facilitate a discussion about why more alternative energy sources are not currently used by everyday consumers as well as large American companies and government agencies.
- What would happen if the world ran out of fossil fuels and did not have alternate energy sources available? Think about how this would impact the average person as well as the world economy.
- What are the various forms of pollution you think of when people mention the burning of fossil fuels?
- What are the health risks people face from these types of pollution?
- As a young consumer, do you have any motivation for cutting your consumption of fossil fuels? Why or why not?
4. Understanding the Science of Global Warming
While we hear talk about global warming and holes in the ozone layer of the atmosphere, these ideas can be difficult to imagine because we haven't yet experienced them. In order to fully understand the real threat that global warming represents, students must first understand the science of global warming.
Using the Frequently Asked Questions section (http://www.pbs.org/wgbh/warming/etc/faqs.html) of the "What's Up With the Weather?" Web site, students can learn specific information about what scientists believe causes global warming and what they can do to decrease the amount of greenhouse gasses that are produced and allowed into the environment. After reviewing the information, have students work as a class, small groups, pairs, or individually to create a basic flowchart or other graphic organizer showing what they have learned about what causes global warming and the short and long term effects of global warming.
Extend the lesson by asking students to consider how factors such as politics, economics, and geography make the topic of global warming controversial in the U.S., while other developed countries worldwide accept scientific theories that conclude that global warming is a real threat. (See NOW's International Perspectives on Global Warming, http://www.pbs.org/now/science/climatemediaint.html)
About the Author
Lisa Prososki is an independent educational consultant who taught middle school and high school English, social studies, reading, and technology courses for twelve years. Prososki has worked extensively with PBS authoring and editing many lesson plans for various PBS programs and PBS TeacherSource. In addition to conducting workshops for teachers at various state and national meetings, Prososki also works with many corporate clients creating training programs and materials, facilitating leadership and operations workshops, and providing instructional support for new program rollouts. Prososki has authored one book and also serves as an editor for other writers of instructional materials.