A heated controversy

By reading two articles about global climate change, your kids can learn more about how some air pollutants may be affecting our climate. Begin by asking the kids to tell you what they know about climate change, often referred to as "global warming." Then use the background information in the NatureScope: Pollution-Problems and Solutions issue to talk about the greenhouse effect and greenhouse gases, such as carbon dioxide and CFCs (see the Bibliography for resource listings).

Next, explain that although most scientists agree that the increasing amounts of carbon dioxide, CFCs, methane, and other greenhouse gases in the atmosphere will affect the world's climate, there's some disagreement about whether these changes have already begun and how serious the effects will be. Scientists also disagree on how we should react to global climate change.

Now pass out paper and copies of the scientists statements on pages 170-171 to each person and explain that each of these articles expresses a point of view about global climate change. (Neither article was written by a real scientist, but both points of view have been expressed by people in the scientific community.) Give the kids time to read the articles and answer the questions that follow the second one. Afterward discuss the kids' answers using the information under "Is the Heat Really On?" and "A Look at the Facts." Finish up by having the kids brainstorm some ways that they can help reduce the amount of greenhouse gases that are being released into the atmosphere (bike, walk, carpool, or take public transportation whenever possible and encourage friends and family to do the same; conserve electricity and buy energy-efficient appliances; don't buy products made with CFCs; encourage parents to have car air conditioners serviced at stations that can recycle coolant made with CFCs and to have home and car air conditioners checked for leaks).

IS THE HEAT REALLY ON?

1. Scientist 1 thinks that global warming is already underway and we need to cut carbon dioxide and CFC emissions now to slow it. Scientist 2 believes that we can't be sure yet if the world's climate is warming as a result of increased CFC and carbon dioxide levels and that we need to do more research before we take any drastic action.

2. ADVANTAGES: would help cut down on the possibility of causing further global warming; would cut down on pollution in general due to decreasing use of fossil fuels, increasing energy efficiency, and switching to alternative energy; would save money due to use of more energy-efficient appliances.

DISADVANTAGES: would cost more in the short run to develop more energy-efficient cars, factories, and appliances; might eliminate some jobs or cut profits.

3. ADVANTAGES: would result in more knowledge about our atmosphere; would cost less in the short term; would not inflict hardships on U.S. businesses and people in developing countries.

DISADVANTAGES: would not reduce pollution; would cost more in the long run; would increase the likelihood that, later on, it might be too late to stop the warming trend. (Note: Point out that the costs associated with either scientist's recommendation are difficult to estimate.)

4. A possible compromise could include making some of the changes suggested by Scientist 1 to help increase energy conservation, while continuing to do research as Scientist 2 advocated. Some scientist and policy makers support this strategy to slow the potential warming trend without threatening to harm the economies of the U.S. and other countries.

5. Opinions will vary. Point out that decisions about global climate change, like decisions about many complicated environmental issues, are often based on information that may or may not be as complete as people would like. People's values also influence their decisions.

6. It's important to stay informed about scientific issues so that you can better understand problems and can change your daily behaviors to help solve problems. For example, consumers can avoid buying products that contribute to the buildup of greenhouse gases, if they know what the problems associated with these gases are and how their actions contribute to the problems. And people can write to their representatives to encourage them to support environmental legislation.

A LOOK AT THE FACTS

* Overall, average world temperatures have risen about 1°F over the past century. But this hasn't been a constant rise. Between 1940 and 1970, average temperatures dropped.

* Developing countries are expected to rapidly increase their carbon dioxide emissions in the next 20 years, as their populations increase and they acquire fossil fuel-burning technologies.

* Cuts in carbon dioxide and CFC emissions must be made worldwide to be effective. The US. and other developed countries have agreed to supply developing countries with technology and funds to help them replace CFCs.

* Most scientists agree that the increase of greenhouse gases will affect the world's climate. But they're unsure about when these changes will start (if they haven't already), how much the world will warm up or cool down, what specific regions will be affected, and how rapidly the changes will take place.

* Some experts say it will take decades of research before they can be sure if the earth's climate is warming up. Others feel that we have enough evidence now.

QUESTIONS

1. What are the main points brought up by each scientist?

2. What are the advantages and disadvantages of the alternative presented by Scientist 1?

3. What are the advantages and disadvantages of the alternative presented by Scientist 2?

4. Can you think of a course of action that is a compromise between the two plans presented by the scientists?

5. What do you think is the best course of action? Why do you feel this is the best thing to do?

6. Do you think it's important to stay informed about scientific issues? Why or why not? What are some ways you can affect the decisions that politicians make about the environment?