Other types of pollution
The Earth is 4,600 million years old. Modern man has lived on the Earth for only 35,000 years, but in that time, we have changed our planet in many ways. Many of the things we have done are good, but many, many more are not good for the earth.
In big cities, car and buses have polluted the air. Many people in cities now have problems with their health.
Factories have also polluted the land and the water. As a result many rivers and lakes are now dead.
The ozone layer
Around the Earth there is a special type of oxygen called ozone. Ozone is important because it stops ultraviolet radiation from the sun. Many aerosol sprays and factories destroy ozone and they have made a very big hole in the ozone layer. This is very dangerous, because it can cause cancer.
More carbon dioxide
Carbon dioxide in the air has increased a lot (it comes from burning oil, coal and wood). It has formed a 'blanket around the Earth. The heat from the sun cannot escape and so the temperature is rising (the 'green house' effect). This means that the level of the sea is rising and the climate is changing.
Fewer trees all over the world people have cut down millions and millions of trees. As a result many types of animals and plants are now disappearing. Trees are also important because the help to produce oxygen and control the climate.
Hope for the future
These problems are very serious for our future, but we can do something now. In many places they have already taken action to improve the environment. Many countries now use the wind, the sun and the sea to make electricity. In some cities, for example, you cannot drive your car on certain days. In other places they use electric cars and buses. There are also many other things we can do. To reduce traffic pollution we can ....
2.2 Look at the article again. What can we do about each problem? With your partner make some notes. Compare your ideas with the rest of the class.
2.3 Use your notes to continue the article: To reduce traffic pollution we can ....
2.4 Check your understanding. Are these sentences true or false?
1 The earth is 35,000years old
2 Ozone protects us from the sun
3 The temperature of the Earth is rising
4 Write your answers to the questions
5 Why are trees important
6 What is ozone?
7 What is 'the greenhouse effect'?
Sun, wind, sea and the Earth
In many countries they make electricity from coal and nuclear power. People say that coal is very dirty because it makes 'acid rain'. They also say that nuclear power is very dangerous.
There are many alternative ways to make electricity that we can use. Look at the pictures. Do they use these ways where you live? Why can't we use it everywhere? Tell the class your ideas.
Date: 2016-03-03; view: 742