A good discussion

Thai students are often criticised for being too quiet in class. Many people say that they don’t like to participate in discussions. I taught in Thai schools for more than 13 years, so I know that this is only partly true. Sometimes students are quiet in class because they don’t know what to say. This week that shouldn’t be a problem because you will have a lot to say.

First of all, our subject this week is an important one – especially for young people like yourselves. We will be reading and talking about global warming. As you probably know, scientists are worried that we are burning too many fossil fuels like oil and gas. The emissions (waste gases) go into the atmosphere and prevent heat from escaping from the earth. As the earth warms, snow and ice from the polar regions could melt, causing sea levels to rise. If this is true, Bangkok may be under water some time next century.

Recently, scientists, politicians, and business leaders spent two weeks in the Japanese city of Kyoto discussing this subject. Below is a story from the Bangkok Post about that conference. Read it carefully. As a young person, how do your feel about the agreement reached at the conference? As you read the story, you will see there are several synonyms for the word agreement, including pact, accord, and treaty. Writers often use synonyms to avoid having to repeat words too often and boring their readers.

Most of the resistance to the treaty seems to be coming from the United States. Business leaders and politicians there are worried about the negative economic effects that cutting back on the burning of fossil fuels might cause. But, as young people, global warming could have a very negative effect on your lives! You probably don’t want to take that chance. In the next section, I have given you information on five alternative energy sources that could help the Americans and the rest of the world reduce greenhouse gas emissions. Your teacher will divide you into groups and assign you to study one of these energy sources. Then you will present your findings to the class. Pretend you are speaking to the American businessmen and politicians. Try to convince them that they should start considering your energy source as well.

Hydroelectric power Hydroelectric power, of course, refers to energy obtained from water falling over dams. This is one of the cleanest ways to make electricity, giving off no greenhouse gases at all. It is also one of least expensive. Water is a renewable resource – we get more of it every time it rains. Fortunately, in Thailand there are still rivers where dams can be built. And there are other benefits from building dams. They give us a place to store water for use in the dry season and they can help control floods in the rainy season. The huge reservoirs that are created behind the dams are also a source of fish and they can be used for recreation as well.	Suggestions Your friends may challenge you over the huge cost of building dams and the environmental destruction they cause. Point out that you often have to sacrifice something in order to gain something good. You can say that the benefits of hydroelectric power outweigh the disadvantages.
Wind energy Wind is free. Wind is clean. If you live in an area where winds regularly blow at about 20 kilometres per hour, you can use the wind to make electricity. All you need is a modern windmill. Better yet, if you have enough land, you can set up a windmill farm using many windmills working together. Then you can generate enough wind to supply a village. One of the biggest windmills is found in California in a valley between large mountains. It consists of more than 4,000 windmills and it produces as much power as an average nuclear power plant. Right now windmill technology is rather expensive, but it is getting cheaper. In fact, electrical generation using wind is about five times cheaper today than it was in 1980. Suggestions Don’t claim that wind energy is the solution to the world’s energy problems. It is not. At best, scientists say it could supply only about 10 percent of the world’s need next century. But that is very good, because it could greatly reduce the pollution from greenhouse gases. Be prepared for criticism from other students, however. Windmill farms take a lot of land and they can be quite noisy. Point out, however, that the best places for windmill farms are often in remote areas with smaller populations. And engineers are working hard on the noise problem and they are having some success. Anyway, the windmill noise is not at dangerous levels.
Solar energy Sunlight is everywhere and no one can charge you for it. Your only costs in using it is for the equipment to collect it, store it and distribute it. There are two basic ways for using solar energy. First is the "thermal process" where you use a solar collector to heat a gas or liquid which can store and distribute the heat. This is good for heating water for cooking or even heating a whole house. If you need very high heat, you can use special collectors that reflect and concentrate the sun’s light onto a very small place. You may have tried this with a magnifying glass, for example. The second basic method is the use of photovoltaic cells (PVs) which collect energy from the sun to make electricity. PVs are widely used and you may even have used one in an electric calculator or a solar watch. The main use for the PVs today, however, is for remote locations far from electricity generating stations. Suggestions Don’t claim that solar power is the best power source for today. Solar power is excellent for individual homeowners or remote villages, but it is not yet practical to use for a country’s power system. But the future is brighter. For example, PVs are excellent for producing hydrogen which can be a wonderful and clean power source since its waste product is water. And hydrogen can be easily stored, so energy is not lost on cloudy days. Once the world changes from burning fossil fuels to hydrogen, solar energy will become much more important. It is true that PVs contain toxic (poisonous materials) but they can safely be recycled, much like certain types of batteries.
Nuclear power People often oppose nuclear power because of emotion, not reason. Nuclear power is clean and it does not give off any greenhouse gases. It is also safe and reliable. Unlike wind energy or solar energy, nuclear power does not depend on nature for its energy and is therefore very dependable. A very small amount of nuclear material yields a very large amount of energy. And it since a nuclear power station produces electricity – just like a lignite plant or a hydroelectric dam – it is ready for use today. Suggestions Expect to be criticised over safety. Point out that nuclear power plants are being used throughout the world and accidents are rare. The new technology is much safer than that used to build the Chernobyl plant where a bad accident occurred in 1986. That accident caused many people to be afraid of nuclear power but modern plants do not have that danger. Disposing of radioactive waste is a problem, but there are safe places to store it and world governments should work together to see that they are used.
Fuel cells One of the best ways to reduce the use of fossil fuels is to find a new power source for cars. Here is where fuel cells look promising. A fuel cell operates like a battery, producing electricity by combining hydrogen and oxygen. But unlike a battery, it never needs recharging and it will run as long as it has fuel. Refuelling is also very quick and easy. Fuel cells require very little care. A car will wear out much faster than the fuel cells inside it. And the only "waste" product of a fuel cell is pure water – water you can drink! Suggestions You will have to admit that at this time, fuel cells have limited uses. A passenger car powered by fuel cells can reach a top speed of only 60 miles per hour (85 kilometres per hour) and can travel only short distances before the cells need more fuel. Therefore their most practical use is in cities — but this is where they are most needed.

Now that you are ready to present your information to the class, there is still one thing to do to make this activity more interesting and useful. Your friends in the other groups will also have some good information and it may sound quite convincing. However, they may have overlooked some possible problems. Below are common criticisms of each of the alternative energy sources discussed in this lesson. Use this information to ask your friends questions and see if they can answer them satisfactorily. And also look carefully at the criticisms of your own energy source so that you will be ready for questions from your friends.

Hydroelectric energy Dams are extremely expensive to build and the reservoir (lake) behind them covers and destroys huge amounts of valuable forest or farmland, often making thousands of villagers homeless. Dams change the flow of rivers and other waterways, increasing the amount of mud or dirt floating in the water as the water is carried quickly downstream.

Wind energy Windmill farms require huge areas of land in an area where there is plenty of wind all the time. If there is little wind, or if the wind is not consistent, the windmills will be useless. People also complain that windmill farms are very noisy and ugly to look at. And they can be dangerous to birds who sometimes fly into their blades and get killed.

Solar power Sunlight is unpredictable and unreliable. On cloudy days, your solar system may not be very useful. Solar cells can be hazardous and dangerous to the environment since toxic chemicals are used when manufacturing them. If they are not disposed of or recycled properly, these chemicals pose a health risk.

Nuclear power Nuclear power plants are very expensive to build and use extremely dangerous and deadly radioactive material to produce energy. Disposing of waste radioactive material is very difficult and can cause great damage to the environment if not stored properly. Not only is radioactive waste very dangerous today, but it remains radioactive for thousands of years. Nuclear power plants will never be completely safe because the humans that run them make mistakes.

Fuel cells A passenger car can reach a top speed of only 60 miles per hour (85 kilometres per hour) and can travel only short distances before the cells need to be refuelled. Vehicles which run on fuel cells are much more expensive than ordinary gasoline-powered vehicles.

Teacher’s Note

Class discussions in a second language are often much less successful than they should be. Students are naturally hesitant to speak and, unless they have been very well prepared, very little genuine discussion is likely to take place. This week’s lesson is designed to make sure your students are well prepared and we think it will lead to a lively and productive discussion. It has several elements that you can use to design similar discussions in the future:

• It has a timely subject (global warming) and the opening activity is designed to help students understand why it is relevant to them, i.e., global warming is likely to directly affect their lives and the lives of their children.
• The lesson has a reading to start them thinking about the subject.
• The lesson contains a lot of background material which insures that your students will have something to say.
• The background material is designed to be divided up among various groups, thereby insuring that there will be classroom interaction since the different groups will have different things to say.
• The students are given suggestions on how to present the information they are given and how to respond to critical questions.
• The students are given suggestions on how to challenge the information presented by other groups.

Start with a short discussion of global warming and then have your students read the selection from the Bangkok Post. Notice that this is a very recent story on the just-concluded Kyoto conference. The conference sparked a lot of controversy since many of the changes recommended by scientists may cause a lot of economic pain. Make sure that your students understand, however, that if the global warming theories are true, their lives could be greatly affected, especially since they are still very young and have many years ahead of them to live. Many of them could even lose their homes as rising ocean levels could wipe out coastal areas.

The main part of the lesson gives background information of five alternative energy sources that could help us greatly reduce emissions from the so-called greenhouse gases. Divide your students into groups with each group responsible for giving information about one energy source. Make sure each group tries to give its information as persuasively as possible as though they really believe what they are saying.

Before the actual presentations take place, however, have each group read through the information in the follow-up section. Have them use this information to ask challenging questions of the other groups as they present their information. You might also want to have your students try to find additional information to strengthen their arguments.

•This lesson was prepared by Acharn Terry Fredrickson, BA Stanford, MA (TESL) University of Minnesota, Manager of the Educational Services Department at the Bangkok Post and general editor of this programme. This week Acharn Terry also had the help of an energetic group of university teachers plus a group of university students.