《臭氧层空洞》PPT课件.ppt

Lesson 3,Ships in the Desert Al Gore,The introduction of the text:,Objectives of Teaching,To comprehend the whole textTo lean and master the vocabulary and expressionsTo learn to paraphrase the difficult sentencesTo understand the structure of the textTo appreciate the style and rhetoric of the passage.,1.Introduction about the author,Al Gore was born in 1948 in Washington D.C.,U.S.He has been a Senator(1984-1992)representing the State of Tennessee,and U.S.Vice-President(1992-2000)under President Bill Clinton.He ran for the Presidency against George W.Bush jr.but the latter won the closely tied election and has become the 43rd American President.The text is taken from Al Gores book Earth in the Balance,Al Gores profound analysis of where humanity has gone wrong ranges across history,politics,science,economics,psychology,philosophy,and religion.,Gore demonstrates that the quality of our air and water is urgently at risk.He clearly illustrates how problems that once were regional have now become global.Gore argues for a worldwide mobilization to save us from disaster.,2.Detailed study of the text,Ships in the DesertWhats the meaning of the title?What does the author try to tell us through his article?,Para.1 typical example of environmental destruction,Why did the writer go to the Aral Sea?What did he see there?,the prospects of a good catch looked bleak:,a good catch did not look promising/hopeful.an understatement,the Aral sea,The Aral Sea:*located in Uzbekistan and Kazakhstan*historically a saline lake*In 1960 the worlds fourth largest lake,the size of the entirety of Southern California*in the center of a large,flat desert basina prime example of a dynamic environment,Americas Great Lakes,*the group of five freshwater lakes,central North America,between the United States and Canada,largest body of fresh water in the world From west to east,they are Lake Superior,Lake Michigan,Lake Huron,Lake Erie,and Lake Ontario HOMESH stands for Huron,O for Ontario,M for Michigan,E for Erie and S for Superior.,comparable:,something that is comparable to something else is a)as good as/as big as/as important as the other thing;b)similar to the other thing e.g.This dinner is comparable to the best French cooking.,to feed it has been diverted in an ill-considered irrigation scheme to grow cotton in the dessert:,to flow into the sea has been turned away to irrigate the land created in the desert to grow cotton.The scheme was an ill-conceived one because it failed to take into consideration the ecological effect.,Para.2 thesis statement:,My search for the underlying causes of the environmental crisis has let me to travel around the world to check and study cases in order to find out the basic causes behind the environmental crisis,What does it mean?,I traveled around the world because I wanted to see,check and study cases of such destruction in order to find out the basic causes behind the environmental crisis.This sentence expresses the main idea and indicating the development of a causal essay.,Trans-Antarctic Mountains,Antarctica is icy cold.Trans-Antarctic Mountains divided it into the East Antarctic and West Antarctic subcontinents.,China has set up two scientific research stations there:Zongshan Station in the East and Great Wall in the West.,the sun glaring at midnight through a hole in the sky,the sun shining at midnight through the ozone depletiona hole:ozone depletion 臭氧层空洞,about the tunnel he was digging through time:,about the tunnel he was drilling for samples from the glacier,which estimates the time.The deeper he drilled,the farther the sample in time;in other words,the surface of the glacier is an indication of recent time while the deeper part of the glacier tells of situation of a much more remote period.,He moved his finger back in time to the ice of two decades ago:,Following the layers of ice in the core sample,his finger came to the place where the layer of ice was formed 20 years ago.,Clean Air Act:,American Congress passed the Clean Air Act in 1970,which is one of the oldest environmental laws of the U.S.as well as the most far-reaching,the costliest,and the most controversial.,two continents,South America and Antarcticaleast accessible place on earth:the place which is the most difficult to get to in the world,Para.3 the global warming seen in the Antarctic,Whats Paragraph 3 talking about?,Whats the cause of the global warming?,Began with the industrial revolution,Industry meant coal:,the development of industry meant the use of large amount of coal as fuel to generate power.,-bringing risingwith its ability warm the earth:,adverbial of result:making the amount of carbon dioxide in the atmosphere grow;heat cannot easily get through carbon dioxide and go into the high altitude so carbon dioxide plays the role of a cover,keeping the heat near the earth.,upwind from the ice runawayscientists monitor the airto chart the course of that inexorable change:,upwind from the ice runaway where the ski plane lands and keeps its engines running so that the metal parts will not be frozen solid,scientists watch the air several times every day to mark the course of that unalterable change.upwind:in the direction from which the wind is blowing or usually blows to chart the course:to show the onward movement on an outline map,graph:usually a mathematical diagram,Para.4 a thinning cap as the result of Arctic air warms,What caused the thinning of the polar ice cap?,global warming,snowmobile,a kind of motor vehicle for traveling over snow,usually with steer able runners at the front and tractor treads at the rearrendezvous point:the place where a submarine was to pick them upA rendezvous is a place where you have arranged to meet somebody often secretly.,to secure the release of previously top secret data:,to ensure the making public of data which was originally classified as top secret.,sonar:,U(an acronym for sound navigation ranging)an apparatus using sound waves for finding the position of underwater objects,such as mines or submarines声纳（利用声波探测如水雷或潜艇等的水底目标的仪器）Baiqi dolphins have sonar.Bats have sonar.,I was standing when separate sheets collide:,I was standing in the vast scene of snow which was fearfully beautiful,windswept and shining white,with the stretch of ice field characterized by small ridges because of the force of the collision of the separate layers.eerily:mysteriously,especially in such a way as to frighten or disturbsnowscape:scene of snow.cf.landscape and seascape.,the consequences of a thinning cap could be disastrous:,the result of a thinning cap may indicate the possibilities of disasterscould:the word indicates“possibilities”,And why could the thinning of the polar ice cap be disastrous to the world?,Because the polar cap plays an important role in the worlds weather system,the consequences of a thinning cap could bring about dramatic changes in the ecological pattern.For example,it will bring large amount of water which will raise the ocean level and cause some floods.,Para.5 the rising temperature of the earth,.Considering such scenarios is not a purely speculative exercise:Thinking about how a series of events might happen as a consequence of the thinning of the Polar cap is not just a kind of practice in speculation,it has got practical value.,the pattern of ice distribution controversial claim:,the regular way ice is distributed a statement which some scientists still do not completely accept,the Arctic Circle,an imaginary line drawn round the world at a certain distance from the most northern point(the North Pole),north of which there is no darkness for six months of each year and almost no light for the other six months.cf.the Antarctic Circletundra:any of the vast,nearly level,treeless plains of the Arctic regions,Para.6 the images of destruction at the equator,billowing:,large swelling mass of billow v.When smoke or cloud billows,it moves slowly upwards or across the sky,Amazon rain forest,The Brazilian Amazon contains about a third of the Earths remaining tropical forest and a very high portion of its biological diversity.One hectare(2.47 acres)of Amazonian moist forest contains more plant species than all of Europe.Yet still it is being destroyed just like other rainforests around the world.,fast pasture for fast-food beef:,Bit by bit trees in the rain forest are felled and the land is cleared and turned into pasture where cattle can be raised quickly and slaughtered and the beef can be used in hamburgers.fast pasture for fast-food beef:alliterationPay attention to the connection of the two“fasts”in fast pasture and fast food.With that comes the“fast”disappearance of the rain forest.,the dry season:,ant.in the wet seasonthe rainy seasonsimilarly:the football season,the breeding season,the planting season,the holiday season,the harvest season,the cold season,the tourist season,the game season,a season of filmin season:Ant.be out of seasonseason v.e.g.season the food with salt,with more than one Tennessees worth of rain forest,the area of rain forest burned in one year is bigger than the state of Tennessee.worth:equal in area or sizeslash:cut with a sweeping stroke,we are silencing thousands of songs we have never even heard:,Since miles of forest are being destroyed and the habitat for these rare birds no longer exists,thousands of birds which we have not even had a chance to see will become extinct.,How will the destruction of the Amazon rain forest affect the earths ecological balance?,Fewer rainforests mean less rain,less oxygen for us to breathe,and an increased threat from global warming.,Para.7 images of destruction seen almost anywhere,What does the writer call“ghosts in the sky”?,“noctilucent clouds”,How are they formed?,They are formed because of the huge buildup of methane gas in the atmosphere,released from landfills,from coal mines and rice paddies,from billions of termites that swarm through the freshly cut forestland,from the burning of biomass and from a variety of other human activities.,On some nights that signals the loss of ecological balance now in progress:,On some nights,in the area at a high northern latitude,the sky alone presents another example of ill omen showing.There is ecological imbalance and this kind of imbalance is developing.in high northern latitude 在北纬高纬度地区cf.longitude经度,This“luminous cloud”occasionally appears when the earth is first hidden in the evening darkness;shining unsteadily above us with a partially transparent whiteness,these clouds dont seem natural,“noctilucent cloud”,noctilucent cloud:,nocti-means night;lucent means shining,translucentdesignating or of a luminous cloud visible at night translucent:partially transparent,landfills:garbage disposal,methane is emitted from garbage disposal,from coal mines and rice fields,from billions of termites（白蚁）moving in large numbers through the freshly cut forestland,from the burning of amount of living organism in a particular area and from a variety of other human activities.,Even though noctilucent clouds to the surface far beneath them,The implication is that the night comes earlier than the upper part.The balance between day and night is broken.altitudes:a high areae.g.At high altitudes it is difficult to breathe.,Para.8 human attitudes towards the images of destruction,What should we feel toward these ghosts in the sky:What should our attitude be toward these noctilucent clouds in the sky?,the mix of emotions we feel at the zoo:,the mix of emotions we feel at the zoo:on the one hand we feel excited about seeing those animals,but on the other hand,we feel sorry for them because they have been deprived of freedom.Should it only be a feeling of surprise and admiration or a combination of different feelings we experience in the zoo?,feel awe for our own power:,feel amazed and frightened at our own power.,upset the balance between daylight and darkness,Just as men are killing such large number of elephants for their tusks that the species will soon extinguish,we are using and destroying resources in such a big amount that we are disturbing the balance between daylight and darkness.,greenhouse gases,gases that will trap heat at the surface of the earth like a greenhouse and ranks third only to carbon dioxide and water vapor in total volume.This means of all the gases,water vapor occupies the largest portion,carbon dioxide the second.Methane-natural gas,greenhouse gases-the third,the chemistry of the upper atmosphere:,the chemical composition of the upper atmosphere,shouldnt it startle us with a spectral light?Or have our eyes human civilization and the earth?,two rhetorical questionsit should startle us;our eyes should not haven adjusted so completely to the bright lights of civilization that we cant see.,what they are,Or have we been so accustomed to the bright electric lights that we fail to understand the threatening implication of these clouds,a physical manifestation of the violent collision between human civilization and the earth?,we fail to understand that it is a glaring sign of the violent clash between human activity and nature?,Para 9.humans puzzling response,Even though it is sometimes hard to see their meaning,we have by now all witnessed surprising experiences:to understand the threat of these clouds,What are the surprising experiences that signal the damage from our assault on the environment mentioned in the paragraph?,more hot days,quicker sunburn,and more debate on garbage disposing matter.,-whether its the frequencywith growing mountains of waste:,whether it is the fact that recently there are more hot days when the temperature is over 100 degrees Fahrenheit(=38 degree Celsius),or the fact the sun burns our skin more quickly in recent times,or the fact that the debate over the way of disposing of the growing amount of waste matter comes up more frequently.,But our response to these signals is puzzling:,But our reaction to these signals is so baffling that it is difficult to understand.,To come at the question another way:,To approach the question in a different way;to put the question differently,Why havent we launched a massive effort to save our environment?,Why havent we started a large-scale movement to save our environment?,some images,Why do some signs so alarm us that we immediately take action and concentrate on ways of dealing with them effectively?some images:e.g.white pollution,(immediate action:stop producing sandstorm(immediate action:plant grass and trees),other images.less painful distraction,And why do other signs,though sometimes no less striking,only cause a kind of loss and inactivity and we concentrate our attention not on the ways to deal with them but instead,on some other substitutes which are easy to get and less painful?other images:e.g.gases from cars(distraction:people still want cars,and have an easy and less painful way to deal with this issue,say,its a natural cycle,not because of human activities),Para.10 the importance of organizing our thoughts,it may be