CHAPTER 4 WEATHER AND CLIMATE
Unit 4 Weather and Climate
Conversations
Ted adn Lisa are drinking coffee.
Look,it is sunny today,isn't it?
Yeach,I like sitting in the sun,
drinking coffee and listening to the light music.
You really know how to lead a comfortable life and enjoy yourself.
A piece of bad news for you:it's forecasted that it will be cloudy tomorrow.
It's so changeable!Maybe the day after tomorrow,it will be snowy.
You're such a smart boy.It is predicted to snow.
Really?That's great!If so,we can buy a roll of film to take photos,
and invite our friends Amy,Martin and Sally to play with snowballs.
And we can also heap up a snowman standing on our playground!
So it is not bad but good news.
May your dream come true.
Wang Lin is talking with Alice about the recent weather.
How are you doing these days?
Fine,and you?
Me too.It's so hot and muggy today.
Yes.The weather has been dry for days.
It's reported that the temperature today rises to about 40C.
Oh,I see.The heat makes my flowers fade,
my little dog"Gege"is lying on the ground with its tongue strectching long.
God damn!Could you remember the flood last month?
Sure.It was raining cats and dogs.Luckily I was staying at home that day.
A terrible flood.Some people lost their lives.Poor poeple!
The flood is dangerous,and our government ha asked people to be mindful of heat,
extreme heat may also cause death.
Take it easy.The fall is coming and the heat will be finally over.
I hope so.
Yang Ming asks his teacher,Mr.Zhang,some questions about the climate.
Good morning,Mr.Zhang.
Good morning,any questions?
Yes,could you tell me the difference of climate between Beijing and Kunming?
Of course.Beijing is situated in the North and Kunming in the Southwest.
Is the climate related to the latitude?
Yes,Beijing is in the high latitudes while Kunming in the low latitudes.
Does the latitude influence the temperature?
Certainly,it's colder in Beijing than in Kunming as a whole.
The weather in Beijing is very bad.
How?Can you explain it in detail?
It's cloudy and windy.Through the whole year,the wind blows very hard.
The dirt spreading in the air can make people dirty.
It can even get through the window and fall on your furniture.
But the strong wind offers a good chance to fly kites.What about Kunming?
It's warm and sunny.The weather si agreeable,comfortable and humid.
The range of temperature is unnoticeable.
In short,that means it's like spring all the year round.
You're right.
Thank you very much.
Aaron is calling his girlfriend,Helen.
Darling,what are you busy with now?I am missing you very much.
Next week,I have a 3-day vacation.Let's make a trip.
Great!Where do you like to go?The South or the North?
The temperature in the North is below zero.
The worst is that it has sonowed there for days.
But I enjoy the cold weather.
It must be refreshing after a hot and muggy summer we spent.
It was terribly hot indeed.If we go southward,
it's unnecessary to travel with more clothes,the weather is fairly agreeable!
Cold as it is in the North,we can seize the opportunity to ski.
Skiing is so exciting and challenging!
Ok,this time,I'll follow you.
Next time,let's go travelling in the South for surfing.
passage Our Changing Atmosphere
According to the National Academy of Sciences,
the Earth's surface temperature has risen
by about 1 degree Fahrenheit in the past century,
with accelerated warming during the past two decades.
There is new and stronger evidence that most of the warming
over the last 50 years is attributable to human activities.
Human activities have altered the chemical composition of the atmosphere
through the buildup of greenhouse gases
-primarily carbon dioxide,methane,and nitrous oxide.
Energy from the sun drives the earth's weather and climate,
and heats the earth's surface;in turn,the earth radiates energy back into space.
Atmospheric greenhouse gases(water vapor,carbon dioxide,and other gases)
trap some of the outgoing energy,
retaining heat somewhat like the glass panels of a greenhouse.
Without this natural"greenhouse effect",
temperatures would be much lower than they are now,
and life as known today would not be possible.
Thanks to greenhouse gases,
the earth's average temperature is a more hospitable 60F.
However,problems may arise
when the atmospheric concentration of greenhouse gases increases.
Scientists generally believe
that the combustion of fossil fuels and other human activities
are the primary reason for the increased concentration of carbon dioxide.
What has changed in the last few hundred years
is the additional release of carbon dioxide by human activities.
Fossil fuels burned to run cars and trucks,heat homes and businesses,
and power factories are responsible for about 98%of US carbon diozide emissions,
24%fo methane emissions,and 18%of nitrous oxide emissions.
Increased agriculture,deforestation,landfills,industrial production,
and mining also contribute a significant share of emissions.
In 1997,the United States emitted about one-fifth of total global greenhouse gases.
The 20th century's 10 warmest years
all occurred in the last 15 years of the century.
Of these,1998 was the warmest year on record.
The snow covers in the Northern Hemisphere
and floating ice in the Arctic Ocean have decreased.
Globally,sea level has risen 4-8 inches over the past century.
Worldwide precipitation over land has increased by about one percent.
The frequency of extreme rainfall events
has increased throughout much of the United States.
Increasing concentrations of greenhouse gases
are likely to accelerate the rate of climate change.
Scientists expect that the average global sirface temperature
could rise 1-4F(0.6-2.5C)
in the next fifty years,and 2.2-10F(1.4-5.8C)in the nxt century,
with significant refional variation.
Evaporation will increase as the climate warms,
which will increase average global precipitation.
Soil moisture is likely to decline in many regions,
and intense rainstorms are likely to become more frequent.
Sea level is likely to ris two feet along most of the US coasts.
Calculations of climate change for specific
areas much less reliable than global ones,
and it is unclear whether regional climate will become more variable.
Words and Expressions
atmosphere Fahrenheit accelerated warming
n.大气,空气n.华氏温度adj.加速的n.升温
decade evidence attributable activity
n.十年n.证据,论据adj.可归于..的n.活动;行动
alter chemical buildup greenhouse
v.改变n.化学制品n.组合,集合n.温室
gas carbon dioxide methane nitrous oxide
n.气体二氧化碳n.甲烷,沼气vt.一氧化二氮
radiate atmospheric vapor trap
vt.放射,辐射adj.大气的,大气层的n.水汽,水蒸气vt.捕获,捕捉
outgoing retain panel average
adj.外出的，离开的vt.保持,保留n.面板adj.平均的
hospitable arise concentration combustion
adj.好客的,殷勤的vi.出现,发生n.集中，集合n.燃烧
fossil fuels primary additional release
矿物燃料adj.第一位,主要的adj.另外的,附加的n.释放
truck responsible emission deforestation
n.卡车,敞篷货车adj.有责任n.散发n.采伐森林
landfill minimg contribute emit
n.垃圾掩埋法n.采矿,矿业v.贡献vt.发出,发射
global floating decrease precipitation
adj.全球的adj.漂浮的,浮动的v.减少n.降(雨)量
frequency extreme rainfall increasing
n.频率,发生次数adj.极端的,极度的n.降雨,降雨量adj.日益增加的
regional variation evaporation moisture
adj.地方的,地域性的n.变化vi.蒸发(作用)n.潮湿,湿气
decline intense rainstorm calculation
vi.下降adj.强烈的,特定的adj.暴风雨n.计算,考虑
specific reliable unclear variable
adj.特殊的,特定的adj.可靠的,可信赖的adj.不清楚的adj.可变的,不定的
Exercises
Section I Listening Comprehension
Listen to the record.
Answer each question by choosing A,B,C or D from the four possible choices.
1.Oh,my God,I have difficulty in breathing,
how do th Africans here stand such heat?
Maybe they are used to it.
2.It has been snowing heavily for one week.
So you will know why the vegetables are so expensive.
3.Mary has gone to the theatre in spite of my suggestion.
Why not send her umbrella now?Look up ward,the dark clouds!
4.It's a holiday now.Where would you like to go,the North or the South?
I prefer the South to the North.It's more agreeable-sunny and warm.
5.The temperature today is 20C.
That means it is 2C higher than that of yesterday,
1C lower than that of the da before yesterday.
B
Do you want to know something about the history of weather?
Don't look at the sky.Dont's look for the old weather report.
Looking ar tree rings is more important.
Correct weather reports date back to only one century,
but some trees cn provide an exact record of the weather even further back.
It's natural that a tree would grow best
in a climate with plenty of sunlight and rainfall.
It is also expected that little sunlight
or rainfall would limit the growth of a tree.
The changes from a favorable to an unfavorable climate
can be determined by reading the pattern of ring in a tree trunk.
To find out the weather of ten years ago,
count the rings of a tree trunk form the outside to the inside.
If the tenth ring is far from the other rings,
then it si certain that plenty of sunny and rainy weather occurred.
If the rings are close together,then the climate was bad for the tree.
Studying tree rings is not only important for the history of the weather,
but also for the history of man.
In a region of New Mexico you can find only sand-no trees and no people.
However,many centuries ago a large population lived there.
They left suddenly,why?
A scientist studied patterns of dead tree rings which had grown there.
He decided the people had to leave because they had cut down all the trees.
Trees were necessary to make filrs and buildings.
So,after the people destroyed the trees,they had to move.
Supplementary Reading Extreme Weather
Extreme weather will become more common,experts forecast.
NEW YORK It has been a summer of extremes.
Rains have deluged Europe and Asia,
swamping cities and villages and killing abot 2 000 people.
while drought and heat have seared the American Western and Eastern cites.
What is going on?
The floods and droughts could simply be flickers
in the inherently chaotic weather system,some experts say.
But many warn that such extremes
will be increasingly common as the world grows warmer.
Such a shift could pose big problems in places where water is already
a strained resource,they say.
A warmer world is more likely to be a wetter one,
experts warn,with more evaporation resulting in more rains,
in more heavy and destructive downpours.
But in a troublesome twist,
that world may also include more intense droughts,
as the increased evaporation parches soils between occasional storms.
"In a hotter climate,your chances of being caught with either too much
or too little rains are higher,"said John Wallace,
a professor of atmospheric sciences at the University fo Washington.
And the globe is getting warmer.
The last several decades of global temperature readings
curve up on graphs like the end of a hockey stick.
Climate specialists concluded for the first time last year
that humans were causing most of the warming trend by burning coal and oil,
which release carbon dioxide and other heat-trapping greenhouse gases.
The main way that warming is likely to manifest itself,scientists say,
is through changes in the balance of water as liquid,vapor and ice.
"There si growing evidence now that shifts in the golbal water cycle
are likely to cause potentially catastrophic effects
in several parta of the world,"said Rajendra Pachauri,
an Indian engineer who si the new chairman
of the Intergovernmental Panel on Climate Change.
Still,a scientific debate persists.
Some speciallists say the earth has built-in buffering mechanisms
that can limit extremes.
But manyy other say that past records,
current trends and computer models all point to big changes ahead.
One new study this summer found evidence that Asian monsoon,
as a part of falter in arid,subtropical areas intensified.
Generally,agriculture is expected to falter in arid,
subtropical areas like the eastern Mediterranean and southern Africa,
while flourishing in northern climes,
like the North American wheat belt,
as more precipitation and longer growing seasons boost yields.
But climate specialists say that even there rain
is more likely to fall as field-scouring torrents.
Long-term planners in the western United States are trying to adjust.
Next year,California will for the first time incorporate
climate changes into its five-year water-management plan.
"Water supplies there are already squeezed by growing populations,"
said Jonas Minton,
the deputy director of the California Department of Water Resources.
A warming climate is intensifying the problem,he siad.
"Over the last 50 years,"he siad,
"winter precipitation in the Sierra Nevada mountain region
has been falling more and more in the form of rain,
increasing flood risks,instead of as snow,
which supplies farmers and faucets alike as it melts in the spring."
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