课件27张PPT。Unit 4Global Warming What is a green house? A greenhouse is made of glass and is used for growing plants, especially during cold weather.The air inside is warm because the glass traps the heat from the sun and keeps it from escaping. This makes the greenhouse heat up and so the
plants can grow
throughout the
cold period.How does it work?
What do you think greenhouse
gases do?
Greenhouse gases perform the same fun_ction as the glass in a greenhouse: They trap heat from the sun and therefore warm the earth. This is called the greenhouse effect.
Role playA: a journalist of Earth Care magazineB,C,D,E,F: people interviewedTask:1. What is global warming?
3. What are the effects of global warming?
..........A: Excuse me, I’m XX of Earth Care. May I ask you some questions? ……
B: ……A is interviewing some people in the street about global warming.2. How has this come about?melting glaciers, rising sea levels and floodsand desertificationfamines diseasesReadingThe Earth Is Becoming Warmer – But Does It Matter?
First Reading1.Who wrote the magazine article? what is the name of the magazine?Sophie Armstrong wrote the magazine article.
The name of the magazine is “Earth Care”2.What are the names of the three scientists mentioned in the article?They are Dr.Janice Foster, Charles Keeling and George Hambley3.What do they think about global warming? Do they agree with one another?go upcatastrophevery seriouspositiveproduce morea greater range of animalsThey don’t agree with each other.
4.What are the two graphs about?5.What are the two
graphs about?Graph 1 is about the temperature difference from long-term average,1860-2000
Graph 2 is about the carbon dioxide content in the atmosphere,1957-1997.5.What are the two graphs about?Choose the best answer1. Who found out the amount of carbon dioxide in the atmosphere from 1957 to 1977? A. Dr. Janice Foster. B. Charles Keeling. C. George Hambley. D. Sophie Armstrong.Second Reading2. The author probably agrees that ________ A. actually global warming is good for man. B. we should do nothing about global warming. C. catastrophes will happen if the globe keeps on warming. D. a lot remains to be found out about the effects of global warming.
Third ReadingRead the article carefully and finish Part 2 on page 271.The temperature last century didn’t increase much.
2.Everyone believes that global warming is caused by the activities of humans.
3.Janice Foster believes that global warming is caused by burning fossil fuels.
4.Nature gas is a greenhouse gas.
5.Carbon dioxide is a byproduct of
burning fossil fuels. F F T F T6.People accept Charles Keeling’s data because he took accurate measurements.
7.Flooding could be one of the effects of future global warming.
8.George Hambley believes scientists are just guessing about the effects of global warming.
9.George Hambley is worried about the effects of carbon dioxide on plant growth
10.It is clear what the effects of global warming will be. T T T F F.Does Sophie Armstrong support a clear opinion?
No, she doesn’t state it clearly.Question main ideaPart1 (para1)Introduce a debate over the issue of global warmingPart 2 (para2- 3)Part 3 (para4-8)Part 4 (para9)Talk about how global warming comes aboutList two different attitudes among scientists towards global warmingIt’s up to readers to think and decide whether people should do sth. about global warming or not 4 partsDiscussion We should do nothing about global warming.Do you agree or disagree with the statement?
Give some reasons. Homework How is the text organized?
preview the language points.
Finish the exercises on Page 28.
