How the greenhouse effect works

Gases like (1) carbon dioxide are important for the Earth's temperature. They let heat from the Sun reach the ground, and keep it there. In this way, they help to keep the Earth's temperature at the ideal level. However, human activities are destroying the natural (2)............of these gases. When we burn fossil fuels like (3).............oil and gas, we produce too much carbon dioxide (CO²). This CO² collects in the atmosphere and (4)............too much heat. We make the problem worse when we cut down (5).............Living trees absorb carbon dioxide and (6)............ oxygen, but when we cut trees down we release carbon dioxide back into the atmosphere.

Exercise 16. Replace the words in italics with a phrasal verb from the box in the correct form. There are two verbs that you won't need.

1. Our planet is in great danger. We all need to accept and deal with the challenges if we are to avoid disaster.

2. We will probably no longer have enough oil in the next 60 years, so we need to develop renewable energy sources such as wind power.

3. Natural resources like wood and coal are being finished at an ever-increasing rate.

4. We ought to reduce the amount of energy we use; for example,

we should switch off lights when we leave a room.

5. We ought to stop using cars for unnecessary journeys and use public transport instead.

Exercise 17. Underline the correct word in each pair. Then answer the questions with a partner.

1. How many species/forms of birds can you name in English?

2. Which animals may become vanished/extinct in the near future?

3. What kinds of crops are grown/grown up in your country?

4. What do scientists mean by soil/earth erosion and what causes it? Is it a problem in your country?

5. What sort of animals and fish live off the coast/beach of your country, e.g. whales, dolphins?

6. What happens to wildlife if oil tankers dump/drop oil in the seas?

7. Have you had any wildlife catastrophes/misfortunes related to pollution in your country recently?

Exercise 18. Read the text ignoring the gaps for the moment.

1. What information does it give about the causes and effects of global warming?

2. According to the text, what will happen if we don't do something about it now?

Exercise 19. Now complete the exam task. Read the gapped sentences very carefully. Remember, to help you choose the right word, you should:

• pay careful attention to meaning.

• be aware of grammatical patterns such as prepositions after nouns and verbs, and infinitives after verbs.

• look out for collocations and fixed phrases.

• make sure that linking words fit the meaning of the text.

Exercise 20. Read the text below and decide which answer A, B, C or D best fits each space. There is an example at the beginning (0).

0 A recognized B regarded C registered D represented