Ideas for group discussion:

Divide into two teams of “Optimists” and “Pessimists”, give your views on the greenhouse effect.

1. The greenhouse effect and its negative and positive consequences

2. She main "greenhouse gases" and their basic sources.

3. Possible ways of slowing down the greenhouse effect.

CONVERSATIONAL FORMULAS FOR GROUP DISCUSSION:

If you ask me…

Wouldn't you say that...

Don't you agree that...

As I see it…

I'd like to point out, that...

Would you agree that…

Do you think it's right to say that…?

I don't quite see what you mean, I'm afraid.

I don't quite see what you are getting at.

REFERENCE MATERIAL FOR GROUP DISCUSSION:

What is it?

Up in the atmosphere, energy, in the form of light from the sun, streams towards earth, it passes through layers of gases miles above the surface of the earth. As the sun warms the land and sea, energy is reflected back at these gases. But this energy is not in the form of sunlight - it is invisible infra-red energy, which the gases absorb. They trap this heat, and that's where the term "greenhouse effect" comes from. If the greenhouse effect did not exist at all, the earth would be a frozen, lifeless planet, but at the moment it is building up much too fast. The main "greenhouse gases" are carbon dioxide, methane and СFCs.

Electricity

Most of the electricity we use is produced by the burning of fossil fuels - coal, oil and gas. When these are burnt, they give off carbon dioxide. So, whenever you turn on any electrical appliance - hi-fi, light bulb, TV or washing machine - think "Do I really need to use this?" And don't forget to turn it off;

Cars

Cars add to the greenhouse effect because they have carbon dioxide and nitrogen oxide in their exhaust fumes. Car makers began to produce cars that go further on a gallon of petrol, but we are still wasting precious petrol and putting yet more С02 into the atmosphere on pointless car journeys.

Rubbish

Most household rubbish gets buried in landfill dumps. Just because it is out of sight, does not mean it does no harm. Methane is released into the air as the rubbish rots. It is the most effective greenhouse gas - one molecule of it absorbs twenty times as much heat as one molecule of carbon dioxide.

CFCs

Chlorofluorocarbons are well known for the damage they are doing to the ozone layer. They are a double attack on our planet because they are also "greenhouse gases". Aerosols, foam plastic fast-food containers, padding from cushions and cars, coolants from fridges and air conditioners all contain CFCs.

Rainforests

Destroying rainforests has awful consequences. This is adding to the greenhouse effect in two major ways. Trees need carbon to grow. They get it from carbon dioxide (or СO2), and forests absorb millions of tons of it a year. Cut the trees down, and the amount of C02 eaten up is also cut. To make matters worse, most of the wood is burnt. That releases millions of tons of С02 which add to the greenhouse effect.

Rice

Methane is also produced when vegetation rots underwater. That is what happens in the millions of square miles of rice fields all over Asia. As the world's population increases, more rice will need to be grown, releasing yet more methane. It is increasing in the atmosphere at an even faster rate than carbon dioxide.

The sea

The sea absorbs vast quantities of carbon dioxide, which is good. To keep soaking it up at the same rate, the amount of salt in the water should not fall. But water that comes from melting polar ice has no salt in it. It will absorb less carbon dioxide. As the greenhouse effect gets worse, the sea will help us less.

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