高中英语选修六unit4globalwarmingreading课件.ppt

Unit 4,Global Warming,What causes the global warming?,Is global warming caused by a random natural phenomenon?,No!,What causes global warming?,Things that use energy around us or at any other places:,In a house,refrigerator,Overpopulation,smoke from factories,Deforestation and desertification,采伐森林 沙漠化,It is _ that has resulted in global warming.,human activity,energy,Wind energy is used as power to produce electricity .,Windmills风车,where electricity is produced by burning coals.,The coal power stations 煤炭发电站,in which oil is refined（提炼） and made pure（纯净）.,The Oil Refineries,a facility（设备） designed to convert （转化）nuclear energy into electricity.,A nuclear power plant 核电站,on the roof of a house on a bright sunny day are used to collect solar energy, making your house warm or heating your water.,Solar panels 太阳能板,are used to keep back water and raise its level for irrigation (灌溉)or for producing electricity, etc.,The Hydro-electric dams 水电大坝,Renewable or non-renewable?,Renewable or non-renewable?,Coal Oil Natural gas,Wind (wind power) Sun (solar energy) Water (hydro-electric power) Hot springs or geysers (间歇泉) The sea (tidal energy潮汐能) plant waste (biomass energy生物质能 ),Fossil fuels,Non-renewable,Renewable,Sources of energy,Fossil Fuel,coal,oil,gas, ,produce,Fossil fuel (化石燃料): Ancient animal and plant material below the surface of the earth with a high carbon content, such as coal, oil and natural gas, which can be burnt to produce energy. Also known as non-renewable energy because once they are used they have gone forever; they cannot be renewed.,Greenhouse gases!,What are the greenhouse gases? Whats greenhouse effect?,What are the “greenhouse gases”? In the atmosphere surrounding the earth there are gases, which are called “greenhouse gases“, including carbon dioxide, methane(甲烷, 沼气) and water vapor.,Whats the greenhouse effect? It is a natural phenomenon.The “greenhouse gases“ trap heat from the sun and therefore warm the earth.,burning fossil fuels,more heat trapped,result in,byproduct,process,more CO2,Global Warming,Greenhouse,What is a greenhouse ?,A greenhouse is made of glass and is used for growing plants, especially during cold weather.,How does greenhouse work? The glass traps（困住） the heat from the sun and keeps it from escaping. This makes the greenhouse heat up，so the plants can grow in the cold period.,The effects of global warming,Negative effects: 1 cause the sea level to rise; 2 severe storms; 3 flood 4 droughts; 5 famine(饥荒); 6 destruction of species,The effects of global warming,Positive effects: 1 make plants grow faster; 2 crops will produce more; 3 make life better,The Earth is Becoming Warmer - But Does It Matter?,Reading,Listen to the passage,task,Pay attention to the structure of the passage. How to divide the passage into four parts?,Para. 1,Para. 2-5,I,II,Para. 6,III,Para. 7,IV,Introduction,Body,Conclusion,引言,主体,结论,Structure,Main idea of each part,Part 1 (1),B. Introduce a debate over the issue of global warming.,Part 2 (2-5),A. How global warming comes about.,D. List two different attitudes among scientists towards global warming.,C. Its up to readers to think and decide whether people should do something about global warming or not.,Part 4 (7),Part 3 (6),1. a fact ? 2. a question ?,Part.I (1),Answer the questions.,During the 20th century the temperature of the earth rose about one degree Fahrenheit.,So how has this come about and does it matter?,Introduce a debate over the issue of global warming.,Part.II (2-5),How global warming comes about.,Everyone believes that global warming is caused by the_.,human activities,2. _has caused the increase in carbon dioxide.,A. The burning of more and more fossil fuels.,B. The natural phenomenon.,A,Graph I shows the _increase of one degree Fahrenheit between 1860 to 2000.,What is the graph about?,temperature,What is the graph about?,Graph 2 shows the _content in the atmosphere from 1957 to 1997.,carbon dioxide,Part.II (2-5),How global warming comes about.,The rise in carbon dioxide is causing a steady increase in temperature.,burning fossil fuels,more heat trapped,result in,byproduct,process,more CO2,Global Warming,Then we will do an interview, I will be a repoter and two of you will be Dr Foster and George Hambley,interview,Dr Janice Foster,George Hambley,go up,catastrophe,very serious,positive,produce more,a greater _of animals,range,Dr. Janice Foster PK George Hambley,PartIV (7),Does it matter？,Greenhouse gases continues to_ in the atmosphere. _ we start reducing the amount of greenhouse gases, the climate_ warming. No one knows the_ of global warming.,build up,Even if,keeps on,effects,Summary,This passage aims at showing us how global warming_. _ has caused this global warming. It also introduces two different _of sc