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IV. SPEAKING
Human activities and global warming
1. Match the activities (1-3) with their possible effects on the environment (a-f).
1. Cutting down or burning forests
2. Burning coal, oil, and gas
3. Raising farm animals like goats, sheep, and cows
a. When burnt, fossil fuels release greenhouse gases, trapping heat in the atmosphere.
b. When eating, these animals produce a lot of methane. This gas is responsible for nearly one-third of current global warming.
c. Trees use CO2 to grow, so when they are cut down or burnt, the CO2 in the air increases.
d. Carbon from fossil fuels combines with oxygen in the air to form large amounts of CO2
e. Forests store carbon in the trees and soil, and help reduce the global temperature.
f. Forests are cut down to make space for farm animals.
2. Use the sentences in the box to complete the conversation. Then practise it in pairs.
A. First, deforestation leads to more CO2 in the air
B. I think it's cutting down or burning forests
C. This also makes the earth even warmer
D. Well, there are two main reasons
Mark: Mai, which human activity is the main cause of global warming?
Mai: (1) _____.
Mark: Why do you think so?
Mai: (2) _____. (3) _____. Trees use CO2, to grow, so when they are cut down or burnt, CO2, in the air increases.
Mark: I see.
Mai: (4) _____. Forests store carbon in the trees and soil, and help reduce the global temperature. That's why I think cutting down or burning forests is the most serious problem.
Tips
To present your ideas clearly in a discussion, you should:
• state your opinion directly, e.g. I think/ believe the most serious problem is burning coal, oil, and gas.
• introduce your arguments, e.g. There are two main reasons.
• use linking words to order your arguments, e.g. First./Second,...
Besides,/Moreover,/In addition, ...
Last/Finally,...
3. Work in pairs. Talk about the other human activities that contribute to global warming. Use the ideas in 1, the model and the tips in 2 to help you.
4. Work in groups. Decide which human activity contributes to global warming the most. Report to the whole class.
