英语：Unit4 Global warming Period 1优秀教案(新人教版选修6)

英语：Unit4 Global warming Period 1优秀教案（新人教
版选修6）
Unit 4Global warming
单元要览
本单元的中心话题是人类当今面临的环境问题，主要探讨了“全球变暖”和“节约能源”等方面的问题。

由于人类过多使用不可再生能源，大气中二氧化碳的含量逐年增加，导致全球气温上升。

通过学习本单元，让学生了解能源分为“不可再生能源”和“可再生能源”，帮助学生树立“节约能源、保护环境”的主人翁意识。

本单元的主要教学内容如下表所示：
Period 1Warming Up，Pre－reading，
Reading and Comprehending
整体设计
教学内容分析
This is the first teaching period of this unit.The central part of this period is the reading passage with the title of “The Earth Is Becoming Warmer—But Does It Matter？” talking about the global issue which has a great effect on human beings' life.
Warming Up gives six pictures to help students list the sources of energy they can think of in our daily life.Then they will be led to discuss which energy source is “renewable” and which is “non－renewable”．This part is designed to help the students to recall their background knowledge about energy and prepares students for the whole unit.
Pre－reading provides a picture of a greenhouse and then tells us what a greenhouse is and what “greenhouse gases” are.The students will be led to discuss what they think greenh ouse gases do，leading to the topic of the reading passage.
Reading is a passage from an environmental magazine for young people.It puts forward the possible effect of increased carbon dioxide in the atmosphere and different points of view about it.It also analyzes the causes of the earth's increased temperature.It poses questions and encourages students to think about the issues.There are two graphs in it that tell us the “temperature difference from long－term average,1860－2000”and “carbon dioxide content in the atmosphere,1957－1997”．Characters in the passage—Dr Janice Foster，George Hambley and Charles Keeling are all real persons and their views reflect the views of some scientists today.
Comprehending consists of three written or oral exercises for the students to do so as to help the students to get a better understanding of the text，that is to say，to help the teacher to check how much the students have understood the text.
三维目标设计
Knowledge and skills
1．To know the meanings of the following new words and phrases：
consume(消费；消耗；耗尽)，come about(发生；造成)，random(胡乱的；任意的)，phenomenon(现象)，subscribe(同意；捐赠；订阅；签署文件)，subscribe to(同意；赞成；订购)，fuel(燃料)，quantity(量；数量)，quantities of (大量的)，tend(趋向；易于；照顾)，go up(上
升；增长；升起)，per(每；每一)，data(资料；数据)，result in(导致)，trend(趋势；倾向)，catastrophe(大灾难；浩劫)，flood(洪水；洪灾)，oppose(反对；反抗)，opposed(反对的；对立的)，be opposed to(反对)，consequence(结果；后果)，state(陈述；说明)，range(种类；范围)，even if(即使)，keep on(继续)，glance(看一下；扫视)，steady(平稳的；持续的)，steadily(平稳地，持续地)
2．To learn about some facts and views about global warming.
3．To learn how the information is organized.
4．To develop the students' reading ability by skimming and scanning the passage.
5．To develop the students' speaking ability by talking about global warming.
Process and methods
1．While doing Warming Up the teacher can lead in the topic of this unit by showing students some pictures or videos about sources of energy，making the students recall their own knowledge about energy.
2．During Pre－reading the teacher can go around the classroom and discuss the questions with several students.This discussion should be student－centered and lead them to the topic of global warming.The teacher should also ask the students to look at the graphs in the reading passage and try to find out the general idea of the text.
3．While doing Reading and Comprehending，the teacher may first ask the students to read the text quickly to get the general idea of each paragraph.After reading the passage，students are encouraged to answer some questions and discuss the text structure.
4．To consolidate the contents of the reading passage，the students should be required to retell the text in their own words at the end of the class.
Emotion，attitude and value
1．To make students realize the harm of global warming and the importance of environmental protection.
2．To develop students' sense of cooperative learning.
教学重、难点
1．To enable the students to learn about global warming and to develop their reading ability.
2．To enable the students to talk about what we should do to prevent global warming.
教学过程
Step 1Warming up
1．Warming up by reading and talking：
Read through the exercise with the class.Put students in groups of four to talk about what we use energy for，what are the sources of these energy and whether the sources are renewable or non －renewable.
Suggested answer：The six photos are：windmills；a coal power station；an oil refinery；a nuclear power plant；solar panels；a hydro－electric dam.
2．Warming up by discussion：
Draw a form on the blackboard as follows：
Things that use energy Sources of energy Renewable/non－renewable
Let the students have a discussion and collect suggestions from students and write them under the appropriate heading.
Suggested answer：
Things that use energy Sources of energy Renewable/non－renewable
lights
heating television cassette player video recorder computer
fridge
stove
hairdryer
...
coal non－renewable
oil non－renewable natural gas non－renewable wind power renewable
solar energy renewable nuclear energy non－renewable hydro－electric
power
renewable biomass energy renewable geothermal energy renewable tidal energy renewable
Step 2Pre－reading
1．Show a picture of a greenhouse to students and ask them what a greenhouse is made of and
what its purpose is.
Suggested answer：It's made of glass and plants can grow in it when it's cold outside.
Ask the students how it works.
Suggested answer：The glass traps the heat from the sun，making the air warm so that plants grow better.
2．Ask students what they think “greenhouse gases” are and what they think greenhouse gases do.Look at the picture above and explain it to their partners.
Suggested answer：Greenhouse gases perform the same function as the glass in a glasshouse：they trap the heat of the sun and keep the air surrounding the earth warm.This is called the greenhouse effect.)
Step 3Reading and comprehending
1．Fast reading
Ask students to read the passage quickly so as to get the key words and general idea of each paragraph and answer the following questions：
(1)What is the main topic of the article?
________________________________________________________________________
(2)Who wrote the magazine article？What is the name of the magazine?
________________________________________________________________________
(3)What are the names of the three scientists mentioned in the article？Do they agree with one another?
________________________________________________________________________ Suggested answers：(1)Global warming/the warming of the earth.(2)Sophie Armstrong，Earth Care.
(3)Dr Janice Foster，Charles Keeling，George Hambley.They don't agree with each other.
2．Detailed reading
(1)Read the passage carefully and judge whether the statements are true(T) or false(F)．
①Janice Foster believes that global warming is caused by the burning fossil fuels.()
②Natural gas is a greenhouse gas.()
③Carbon dioxide is a byproduct of burning fossil fuels.()
④People accept Charles Keeling's data because he took accurate measurements.()
⑤Flooding could be one of the effects of future global warming.()
⑥George Hambley believes scientists are just guessing about the effects of global warming.()
⑦George Hambley is worried about the effects of carbon dioxide on plant growth.()
⑧It is clear what the effects of global warming will be.()
(Suggested answers：TFTTTTFF)
3．Structure analyzing
Ask students to read the text carefully and try to find out how many parts they can divide the text into and find out the main idea of each part.
Part Main idea
Part 1(Paragraph ______)
Part 2(Paragraphs ______ to ______)
Part 3(Paragraphs ______ to ______)
Part 4(Paragraph ______)
Suggested answer：
Part Main idea
Part 1(Paragraph 1) To introduce a debate over the issue of global warming.
Part 2(Paragraphs 2 to 5) To illustrate how global warming comes about.
To list two different attitudes among scientists towards global Part 3(Paragraph 6)
warming.
It's up to readers to think and decide whether people should do Part 4(Paragraph 7)
something about global warming or not.
Step 4Language study
Dealing with any language problem if any(words or sentences students might not understand)to help the students to have a better understanding of the text.
Step 5Listening，reading aloud and underlining
Ask students to read the passage aloud to the tape and let them pay attention to the pronunciation of each word and the pauses within each sentence.Tell them to pick out all the useful expressions or collocations from the passage while reading and copy them to the notebook after class as homework.
Collocations：come about，There is no doubt that...，subscribe to，due to，greenhouse effect，quantities of，tend to，be trapped in，go up，result in，on the one hand...on the other hand，be opposed to，build up，keep on.
Step 6Retelling
Ask students to talk about global warming in their own words.Give them some key words and expressions on the blackboard.Then let them try to retell the passage.
Step 7Homework
1．Learn the useful new words and expressions in this part by heart.
2．Try to find some data about global warming on the Internet，and show your class in the next period and talk about them.
Step 8Reflection after teaching
________________________________________________________________________ ________________________________________________________________________
教学参考
About Global Warming(关于全球变暖)
Global warming is the increase in the average temperature of Earth's near－surface air and oceans since the mid－20th century and its projected continuation.Global surface temperature increased 0.74±0.18℃(1.33±0.32)between the start and the end of the 20th century.The Intergovernmental Panel on Climate Change(IPCC)concludes that most of the observed temperature increase since the middle of the 20th century was very likely caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation.The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanic eruptions had a small cooling effect after 1950.These basic conclusions have been endorsed by more than 40 scientific societies and academies of science，including all of the national academies of science of the major industrialized countries.
Climate model projections summarized in the latest IPCC report indicate that the global surface temperature is likely to rise a further 1.1 to 6.4℃(2.0 to 11.5)during the 21st century.The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions.Most studies focus on the period up to the year 2100.However，warming is expected to continue beyond 2100 even if emissions stop，because of the large heat capacity of the oceans and the long lifetime of carbon dioxide in the atmosphere.
An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation，probably including expansion of subtropical deserts.Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers，permafrost and sea ice.Other likely effects include changes in the frequency and intensity of extreme weather events，species extinctions，and changes in agricultural yields.Warming and related changes will vary from region to region around the globe，though the nature of these regional variations is uncertain.
Political and public debate continues regarding global warming，and what actions(if any)to take in response.The available options are mitigation to reduce further emissions；adaptation to reduce the damage caused by warming；and，more speculatively，geoengineering(地球工程)to reverse global warming.Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions.。