[00:00.00] CHAPTER 4 WEATHER AND CLIMATE
[00:14.29]Unit 4 Weather and Climate
[00:20.95]Conversations
[00:24.42]Ted adn Lisa are drinking coffee.
[00:30.38]Look,it is sunny today,isn't it?
[00:34.93]Yeach,I like sitting in the sun,
[00:39.50]drinking coffee and listening to the light music.
[00:44.15]You really know how to lead a comfortable life and enjoy yourself.
[00:50.10]A piece of bad news for you:it's forecasted that it will be cloudy tomorrow.
[00:57.76]It's so changeable!Maybe the day after tomorrow,it will be snowy.
[01:04.91]You're such a smart boy.It is predicted to snow.
[01:10.48]Really?That's great!If so,we can buy a roll of film to take photos,
[01:18.94]and invite our friends Amy,Martin and Sally to play with snowballs.
[01:25.50]And we can also heap up a snowman standing on our playground!
[01:31.74]So it is not bad but good news.
[01:36.71]May your dream come true.
[01:40.86]Wang Lin is talking with Alice about the recent weather.
[01:49.51]How are you doing these days?
[01:53.48]Fine,and you?
[01:57.13]Me too.It's so hot and muggy today.
[02:02.78]Yes.The weather has been dry for days.
[02:07.95]It's reported that the temperature today rises to about 40C.
[02:15.31]Oh,I see.The heat makes my flowers fade,
[02:21.56]my little dog"Gege"is lying on the ground with its tongue strectching long.
[02:28.92]God damn!Could you remember the flood last month?
[02:35.19]Sure.It was raining cats and dogs.Luckily I was staying at home that day.
[02:43.13]A terrible flood.Some people lost their lives.Poor poeple!
[02:50.79]The flood is dangerous,and our government ha asked people to be mindful of heat,
[02:58.02]extreme heat may also cause death.
[03:02.47]Take it easy.The fall is coming and the heat will be finally over.
[03:08.81]I hope so.
[03:12.47]Yang Ming asks his teacher,Mr.Zhang,some questions about the climate.
[03:20.65]Good morning,Mr.Zhang.
[03:24.30]Good morning,any questions?
[03:28.74]Yes,could you tell me the difference of climate between Beijing and Kunming?
[03:35.82]Of course.Beijing is situated in the North and Kunming in the Southwest.
[03:43.97]Is the climate related to the latitude?
[03:48.94]Yes,Beijing is in the high latitudes while Kunming in the low latitudes.
[03:56.77]Does the latitude influence the temperature?
[04:01.92]Certainly,it's colder in Beijing than in Kunming as a whole.
[04:08.08]The weather in Beijing is very bad.
[04:12.66]How?Can you explain it in detail?
[04:17.38]It's cloudy and windy.Through the whole year,the wind blows very hard.
[04:24.93]The dirt spreading in the air can make people dirty.
[04:30.39]It can even get through the window and fall on your furniture.
[04:36.04]But the strong wind offers a good chance to fly kites.What about Kunming?
[04:43.40]It's warm and sunny.The weather si agreeable,comfortable and humid.
[04:51.06]The range of temperature is unnoticeable.
[04:55.42]In short,that means it's like spring all the year round.
[05:02.08]You're right.
[05:05.35]Thank you very much.
[05:08.79]Aaron is calling his girlfriend,Helen.
[05:15.66]Darling,what are you busy with now?I am missing you very much.
[05:22.80]Next week,I have a 3-day vacation.Let's make a trip.
[05:29.43]Great!Where do you like to go?The South or the North?
[05:35.88]The temperature in the North is below zero.
[05:40.45]The worst is that it has sonowed there for days.
[05:46.02]But I enjoy the cold weather.
[05:50.17]It must be refreshing after a hot and muggy summer we spent.
[05:56.73]It was terribly hot indeed.If we go southward,
[06:03.49]it's unnecessary to travel with more clothes,the weather is fairly agreeable!
[06:10.86]Cold as it is in the North,we can seize the opportunity to ski.
[06:17.70]Skiing is so exciting and challenging!
[06:22.88]Ok,this time,I'll follow you.
[06:27.92]Next time,let's go travelling in the South for surfing.
[06:33.69]passage Our Changing Atmosphere
[06:39.02]According to the National Academy of Sciences,
[06:44.45]the Earth's surface temperature has risen
[06:48.89]by about 1 degree Fahrenheit in the past century,
[06:54.54]with accelerated warming during the past two decades.
[07:00.70]There is new and stronger evidence that most of the warming
[07:06.58]over the last 50 years is attributable to human activities.
[07:13.84]Human activities have altered the chemical composition of the atmosphere
[07:20.92]through the buildup of greenhouse gases
[07:25.96]-primarily carbon dioxide,methane,and nitrous oxide.
[07:33.33]Energy from the sun drives the earth's weather and climate,
[07:39.10]and heats the earth's surface;in turn,the earth radiates energy back into space.
[07:48.35]Atmospheric greenhouse gases(water vapor,carbon dioxide,and other gases)
[07:57.49]trap some of the outgoing energy,
[08:02.06]retaining heat somewhat like the glass panels of a greenhouse.
[08:08.31]Without this natural"greenhouse effect",
[08:13.45]temperatures would be much lower than they are now,
[08:18.49]and life as known today would not be possible.
[08:23.95]Thanks to greenhouse gases,
[08:28.71]the earth's average temperature is a more hospitable 60F.
[08:36.57]However,problems may arise
[08:41.43]when the atmospheric concentration of greenhouse gases increases.
[08:47.96]Scientists generally believe
[08:51.91]that the combustion of fossil fuels and other human activities
[08:57.86]are the primary reason for the increased concentration of carbon dioxide.
[09:04.91]What has changed in the last few hundred years
[09:09.75]is the additional release of carbon dioxide by human activities.
[09:16.20]Fossil fuels burned to run cars and trucks,heat homes and businesses,
[09:23.28]and power factories are responsible for about 98% of US carbon diozide emissions,
[09:32.84]24% fo methane emissions,and 18% of nitrous oxide emissions.
[09:40.99]Increased agriculture,deforestation,landfills,industrial production,
[09:49.64]and mining also contribute a significant share of emissions.
[09:55.98]In 1997,the United States emitted about one-fifth of total global greenhouse gases.
[10:05.54]The 20th century's 10 warmest years
[10:10.90]all occurred in the last 15 years of the century.
[10:16.36]Of these,1998 was the warmest year on record.
[10:23.02]The snow covers in the Northern Hemisphere
[10:27.75]and floating ice in the Arctic Ocean have decreased.
[10:33.31]Globally,sea level has risen 4-8 inches over the past century.
[10:40.86]Worldwide precipitation over land has increased by about one percent.
[10:48.72]The frequency of extreme rainfall events
[10:53.90]has increased throughout much of the United States.
[10:59.04]Increasing concentrations of greenhouse gases
[11:04.92]are likely to accelerate the rate of climate change.
[11:10.77]Scientists expect that the average global sirface temperature
[11:16.70]could rise 1-4F(0.6-2.5C)
[11:26.68]in the next fifty years,and 2.2-10F(1.4-5.8C)in the nxt century,
[11:40.84]with significant refional variation.
[11:46.61]Evaporation will increase as the climate warms,
[11:52.25]which will increase average global precipitation.
[11:57.82]Soil moisture is likely to decline in many regions,
[12:03.88]and intense rainstorms are likely to become more frequent.
[12:09.94]Sea level is likely to ris two feet along most of the US coasts.
[12:17.31]Calculations of climate change for specific
[12:23.37]areas much less reliable than global ones,
[12:28.41]and it is unclear whether regional climate will become more variable.
[12:34.47]Words and Expressions
[12:38.83]atmosphere Fahrenheit accelerated warming
[12:42.85]n.大氣,空氣 n.華氏溫度 adj.加速的 n.升溫
[12:46.88]decade evidence attributable activity
[12:51.00]n.十年 n.證據(jù),論據(jù) adj.可歸于..的 n.活動;行動
[12:55.13]alter chemical buildup greenhouse
[12:59.10]v.改變 n.化學(xué)制品 n.組合,集合 n.溫室
[13:03.07]gas carbon dioxide methane nitrous oxide
[13:07.76]n.氣體 二氧化碳 n.甲烷,沼氣 vt.一氧化二氮
[13:12.45]radiate atmospheric vapor trap
[13:16.47]vt.放射,輻射 adj.大氣的,大氣層的 n.水汽,水蒸氣 vt.捕獲,捕捉
[13:20.50]outgoing retain panel average
[13:24.58]adj.外出的,離開的 vt.保持,保留 n.面板 adj.平均的
[13:28.67]hospitable arise concentration combustion
[13:32.80]adj.好客的,殷勤的 vi.出現(xiàn),發(fā)生 n.集中,集合 n.燃燒
[13:36.93]fossil fuels primary additional release
[13:41.05]礦物燃料 adj.第一位,主要的 adj.另外的,附加的 n.釋放
[13:45.18]truck responsible emission deforestation
[13:49.51]n.卡車,敞篷貨車 adj.有責(zé)任 n.散發(fā) n.采伐森林
[13:53.83]landfill minimg contribute emit
[13:57.92]n.垃圾掩埋法 n.采礦,礦業(yè) v.貢獻(xiàn) vt.發(fā)出,發(fā)射
[14:02.01]global floating decrease precipitation
[14:06.08]adj.全球的 adj.漂浮的,浮動的 v.減少 n.降(雨)量
[14:10.16]frequency extreme rainfall increasing
[14:14.39]n.頻率,發(fā)生次數(shù) adj.極端的,極度的 n.降雨,降雨量 adj.日益增加的
[14:18.62]regional variation evaporation moisture
[14:22.96]adj.地方的,地域性的 n.變化 vi.蒸發(fā)(作用) n.潮濕,濕氣
[14:27.29]decline intense rainstorm calculation
[14:31.67]vi.下降 adj.強(qiáng)烈的,特定的 adj.暴風(fēng)雨 n.計算,考慮
[14:36.04]specific reliable unclear variable
[14:40.17]adj.特殊的,特定的 adj.可靠的,可信賴的 adj.不清楚的 adj.可變的,不定的
[14:44.30]Exercises
[14:48.06]Section I Listening Comprehension
[14:53.10]Listen to the record.
[14:56.97]Answer each question by choosing A,B,C or D from the four possible choices.
[15:05.51]1.Oh,my God,I have difficulty in breathing,
[15:12.67]how do th Africans here stand such heat?
[15:18.23]Maybe they are used to it.
[15:22.59]2.It has been snowing heavily for one week.
[15:28.55]So you will know why the vegetables are so expensive.
[15:34.71]3.Mary has gone to the theatre in spite of my suggestion.
[15:41.66]Why not send her umbrella now?Look up ward,the dark clouds!
[15:48.72]4.It's a holiday now.Where would you like to go,the North or the South?
[15:57.26]I prefer the South to the North.It's more agreeable-sunny and warm.
[16:05.02]5.The temperature today is 20C.
[16:11.86]That means it is 2C higher than that of yesterday,
[16:18.49]1C lower than that of the da before yesterday.
[16:24.66]B
[16:27.59]Do you want to know something about the history of weather?
[16:33.23]Don't look at the sky.Dont's look for the old weather report.
[16:39.47]Looking ar tree rings is more important.
[16:44.51]Correct weather reports date back to only one century,
[16:50.16]but some trees cn provide an exact record of the weather even further back.
[16:57.42]It's natural that a tree would grow best
[17:01.96]in a climate with plenty of sunlight and rainfall.
[17:06.93]It is also expected that little sunlight
[17:11.65]or rainfall would limit the growth of a tree.
[17:16.62]The changes from a favorable to an unfavorable climate
[17:22.65]can be determined by reading the pattern of ring in a tree trunk.
[17:29.00]To find out the weather of ten years ago,
[17:34.35]count the rings of a tree trunk form the outside to the inside.
[17:40.60]If the tenth ring is far from the other rings,
[17:45.95]then it si certain that plenty of sunny and rainy weather occurred.
[17:52.30]If the rings are close together,then the climate was bad for the tree.
[17:59.07]Studying tree rings is not only important for the history of the weather,
[18:05.31]but also for the history of man.
[18:10.17]In a region of New Mexico you can find only sand-no trees and no people.
[18:18.63]However,many centuries ago a large population lived there.
[18:25.71]They left suddenly,why?
[18:30.86]A scientist studied patterns of dead tree rings which had grown there.
[18:37.23]He decided the people had to leave because they had cut down all the trees.
[18:44.00]Trees were necessary to make filrs and buildings.
[18:49.46]So,after the people destroyed the trees,they had to move.
[18:55.62]Supplementary Reading Extreme Weather
[19:01.86]Extreme weather will become more common,experts forecast.
[19:07.90]NEW YORK It has been a summer of extremes.
[19:13.83]Rains have deluged Europe and Asia,
[19:18.51]swamping cities and villages and killing abot 2 000 people.
[19:25.27]while drought and heat have seared the American Western and Eastern cites.
[19:31.83]What is going on?
[19:35.98]The floods and droughts could simply be flickers
[19:41.23]in the inherently chaotic weather system,some experts say.
[19:46.98]But many warn that such extremes
[19:51.34]will be increasingly common as the world grows warmer.
[19:56.98]Such a shift could pose big problems in places where water is already
[20:04.35]a strained resource,they say.
[20:08.90]A warmer world is more likely to be a wetter one,
[20:14.25]experts warn,with more evaporation resulting in more rains,
[20:20.31]in more heavy and destructive downpours.
[20:25.35]But in a troublesome twist,
[20:29.92]that world may also include more intense droughts,
[20:35.67]as the increased evaporation parches soils between occasional storms.
[20:42.75]"In a hotter climate,your chances of being caught with either too much
[20:49.59]or too little rains are higher,"said John Wallace,
[20:55.65]a professor of atmospheric sciences at the University fo Washington.
[21:02.21]And the globe is getting warmer.
[21:06.36]The last several decades of global temperature readings
[21:12.01]curve up on graphs like the end of a hockey stick.
[21:17.57]Climate specialists concluded for the first time last year
[21:23.21]that humans were causing most of the warming trend by burning coal and oil,
[21:29.56]which release carbon dioxide and other heat-trapping greenhouse gases.
[21:36.04]The main way that warming is likely to manifest itself,scientists say,
[21:42.39]is through changes in the balance of water as liquid,vapor and ice.
[21:49.23]"There si growing evidence now that shifts in the golbal water cycle
[21:55.08]are likely to cause potentially catastrophic effects
[22:01.01]in several parta of the world,"said Rajendra Pachauri,
[22:07.67]an Indian engineer who si the new chairman
[22:12.74]of the Intergovernmental Panel on Climate Change.
[22:18.07]Still,a scientific debate persists.
[22:23.92]Some speciallists say the earth has built-in buffering mechanisms
[22:29.80]that can limit extremes.
[22:33.56]But manyy other say that past records,
[22:38.42]current trends and computer models all point to big changes ahead.
[22:45.50]One new study this summer found evidence that Asian monsoon,
[22:52.03]as a part of falter in arid,subtropical areas intensified.
[22:57.96]Generally,agriculture is expected to falter in arid,
[23:04.44]subtropical areas like the eastern Mediterranean and southern Africa,
[23:10.68]while flourishing in northern climes,
[23:15.36]like the North American wheat belt,
[23:19.62]as more precipitation and longer growing seasons boost yields.
[23:25.78]But climate specialists say that even there rain
[23:31.34]is more likely to fall as field-scouring torrents.
[23:37.72]Long-term planners in the western United States are trying to adjust.
[23:44.17]Next year,California will for the first time incorporate
[23:50.34]climate changes into its five-year water-management plan.
[23:56.08]"Water supplies there are already squeezed by growing populations,"
[24:02.64]said Jonas Minton,
[24:06.90]the deputy director of the California Department of Water Resources.
[24:12.96]A warming climate is intensifying the problem,he siad.
[24:19.02]"Over the last 50 years,"he siad,
[24:23.56]"winter precipitation in the Sierra Nevada mountain region
[24:29.13]has been falling more and more in the form of rain,
[24:34.77]increasing flood risks,instead of as snow,
[24:40.05]which supplies farmers and faucets alike as it melts in the spring."