Unit 9
Text A
Listening
First Listening
Before listening to the tape, have a quick look at the following words.
greenhouse effect
温室效应
alter
改变
release
排放
carbon dioxide
二氧化碳
tropical
热带的
ecology
生态
global
全球的
pattern
模式
Venus
金星
thermometer
温度计
Second Listening
Listen to the tape again. Then, choose the best answer to each of the following questions.
1. Which of the following topics does the listening passage mainly discuss?
A) The dangers caused by changes in the atmosphere.
B) Problems on the planet Venus.
C) The damage done by different types of pollution.
D) Ways of growing flowers in the winter.
2. What does the term "greenhouse effect" refer to?
A) A "blanket" of green glass being built over some low-lying cities.
B) O1d trees being cut down in order to build houses.
C) A warming of the earth's temperatures.
D) A cloud of green dust on the planet Venus.
3. Which of the following is mentioned as a reason for the buildup of carbon dioxide in the atmosphere?
A) Burning of fuels by cars and factories.
B) A large increase in the number of trees in some areas.
C) A large decrease in the number of trees in some areas.
D) Pollution in the earth's rivers and streams.
4. What changes in global weather patterns might the greenhouse effect create?
A) An increase in rain in some places.
B) A decrease in rain in some places.
C) A shift in the patterns of ocean tides.
D) Both A) and B).
Pre-reading Questions
1. Looking at the title, what do you guess the passage is about? Make predictions, and then read the first paragraph to find out what the "greenhouse effect" is.
2. In the discussion of the "greenhouse effect", what do scientists disagree about? And, what points do they agree on? Skim paragraphs 3 and 4 to look for your answers.
3. How serious of a threat do you consider the "greenhouse effect" to be? Give reasons for your answer.
Hothouse Earth
Kevin McKean
Headlines warned of rising temperatures and melting polar ice caps.
Scientists issued reports on the severe climate changes that could result from the "greenhouse effect" — the gradual warming of the atmosphere caused by an increase in carbon dioxide levels from the burning of fossil fuels, saying that average global temperatures could start to rise within a few decades and reach levels nine degrees Fahrenheit higher than today's temperatures by the end of the next century. This, experts said, could create dangerous changes to global weather patterns. For instance, it could change annual amounts of rainfall, swell or dry up rivers, and raise the level of the seas.
While admitting that this forecast was somewhat uncertain, scientists warned against treating it as a cry of wolf. Although there is considerable debate over how severe the greenhouse effect will be, one thing seems certain: Carbon dioxide levels are on the rise.
Who or what is to blame? Scientists conclude that it is the burning of coal, oil, synthetic fuels, and natural gas. These fossil energy sources release an estimated five and a half billion tons of carbon into the atmosphere each year as colorless, odorless CO2 gas.
The increased carbon dioxide could profoundly affect the way the earth is heated by the sun. The sun's energy strikes the earth mainly in the form of visible light. As the earth heats up, it radiates this energy back into space, but at the much longer wavelengths of infrared light, or heat. Carbon dioxide lets the visible light pass through, but absorbs energy at infrared wavelengths. Thus, the more carbon dioxide there is in the atmosphere, the more the earth's heat is blocked from escaping — just as a blanket holds in the heat of a sleeper's body. In the late 1800s, a Swedish scientist gave this phenomenon its name when he compared it to the way glass shuts in air heated by the sun in a greenhouse.
Some scientists think the greenhouse effect already has begun: Average global temperatures have risen about one degree Fahrenheit in the past ninety years (with a dip from the mid-1940s to 1970). Others argue that the rise could be due to natural temperature ups and downs.
Nevertheless, most scientists agree that the accumulation of carbon dioxide has reached the point where an increase in temperature is sure to take place. One study said average global temperatures probably would rise nearly four degrees by the twenty-first century — a total warming greater than that since the last ice age.
Rising temperatures would be just the beginning. The heating would shift global rainfall patterns, bringing drought to some now-fertile areas and irrigating some deserts. Likewise, mountain glaciers and polar ice caps could melt substantially, causing the seas to rise two feet by the end of the century. Many low-lying communities could be flooded. Worst of all, the effect may be irreversible.
Some have maintained that the world faces such great dangers from population growth, diminishing food supply, and the spread of nuclear weapons that the greenhouse threat seems mild by comparison. Others argue that since the earth has endured a long string of ice ages in the last two million to three million years, any warming is likely to be temporary. Even so, those who try to minimize the problem must also explain away the harsh conditions on the planet Venus. There, a runaway greenhouse effect is thought to account for surface temperatures approaching 900 degrees Fahrenheit; Venus's cloud-shrouded atmosphere is about 97 percent carbon dioxide.
Although few scientists think the earth will go the way of Venus, most agree that the greenhouse problem should be tackled now. City planning should be revised; dykes and reservoirs should be built; an eye should be kept open on the thermometer for the first definite sign that the greenhouse era has arrived.
(636 words)
New Words
hothouse
n. 温室
headline
n. 1. a newspaper heading（报刊的）大字标题
2. (pl.) a brief summary on television or radio of the most important items of news [复数] 新闻提要
*polar
a. of or near the North or South pole 极地的；近极地的
issue
vt. bring out (esp. sth. printed and /or official) for the notice of the public 发布，发行
n. 1. the supply or release of items for use or sale 发给；发行
2. an important topic for discussion or argument（有争议的）重大问题，议题
severe
a. 1. very bad, serious 严重的
2. (of people or their behaviour) strict or harsh 严格的；严厉的
climate
n. the average weather conditions at a particular place over a period of years 气候
*greenhouse
n. 温室，暖房
gradual
a. taking place by a series of small changes over a long time 逐渐的，逐步的
carbon
n. 碳
dioxide
n. 二氧化物
*fossil
a. 化石的
n. 化石
fuel
n. any material burned to produce heat or power 燃料
v. supply sth. or be supplied with fuel （向…）供燃料；（给…）加油
global
a. 1. of or concerning the whole earth 全球的，世界的
2. of, related to, or concerning all or almost all possible considerations 总括的，综合的
Fahrenheit
a. 华氏（温度计）的
pattern
n. a way in which sth. happens, moves, develops or is arranged 型式，模式
annual
a. 1. calculated over a period of a year 每年的；年度的
2. happening every year, usu. once a year 一年一次的
rainfall
n. （降）雨量
swell
v. (cause to) become greater in amount or volume; increase （使）上涨；（使）增长
forecast
n. a statement that predicts sth. with the help of information 预测，预报
vt. say in advance what is expected to happen 预测，预报
considerable
a. great in amount or size; of noticeable importance 相当多的，相当大的；相当重要的
synthetic
a. not naturally produced; artificial 合成的；人造的
release
vt. 1. allow (sth.) to fly, fall, etc. freely 排放，放出
2. set free; allow to go 释放；解放
odo(u)rless
a. having no smell 无臭的
odo(u)r
n. a smell (pleasant or unpleasant) 气味；香气；臭气
profoundly
ad. deeply 深深地
*profound
a. 1. deep; intense 深（度）的；极度的
2. having, showing knowledge or understanding of a subject 深奥的；造诣深的
visible
a. 1. that can be seen 可见的，看得见的
2. noticeable to the mind 明显的，显然的
*radiate
vt. send out (light or heat) 发射（光、热等）
vi. (from) come out or spread in all directions from (sth.) 辐射，散发
wavelength
n. 波长
infrared
a. 红外线的；红外区的
absorb
vt. 1. take in 吸收（水、热、光等）
2. take up all the attention, interest, time, etc., of 吸引（注意），使专注
Swedish
a. 瑞典（人）的
phenomenon (pi. phenomena)
n. a fact or event in nature (or society) as it appears or is experienced by the senses 现象
dip
n. 1. 下降
2. 浸；蘸
argue
v. give reasons for or against sth., esp. with the aim of persuading sb. to share one's own opinion 论证；认定
nevertheless
ad. in spite of that; however 然而，不过
accumulation
n. 积累，积聚
*drought
n. a long period of dry weather, when there is not enough water 长期干旱，旱灾
fertile
a. 1. (of land) which produces or can produce good crops 肥沃的，富饶的
2. producing many young, fruits, or seeds 多产的，丰产的
likewise
ad. 1. also; in addition 也，又
2. in the same way; similarly 同样地
glacier
n. 冰河，冰川
substantially
ad. 1. to a considerable degree; greatly 到相当程度；大量地
2. mainly; in the important part 基本上
substantial
a. 1. large in amount or value; considerable 大量的
2. concerning the most important part or meaning 基本的；大体上的
low-lying
a. 低洼的
community
n. 1.（由同住一地区或一国的人所构成的）社会；社区
2. 团体；界
irreversible
a. that cannot be changed to the original state 不可逆转的
maintain
vt. 1. express firmly or stick to one's point 坚称；断言
2. keep up; retain 维持；保持
*diminish
v. (cause to) become less （使）缩减；（使）变小；减少
nuclear
a. 核子的；原子能的
threat
n. 威胁
mild
a. 1. not serious or harsh 轻微的，不严重的
2. (of people or their behaviour) gentle and kind 温和的；温柔的
comparison
n. 比较，对照
temporary
a. lasting for a limited time only 暂时的，临时的
*minimize, -ise
vt. 1. reduce the true value or importance of (sth.) 把…作最低估计
2. reduce (sth.) to the smallest amount or degree 使减到最少，使缩至最小
harsh
a. severe; stern 严酷的；严厉的
runaway
a. out of control 失控的
account
vi. (for) explain the cause of 说明…的原因，解释
n. a written or spoken report; description 报道；叙述
shroud
vt. 遮蔽；笼罩
cloud-shrouded
a. 被云笼罩的
tackle
vt. try to deal with 着手处理，对付
revise
vt. change (sth.) in order to correct or improve it 修改，修正
dyke, dike
n. 堤，坝
reservoir
n. 水库，蓄水池
thermometer
n. 温度计，寒暑表
definite
a. clear, sure and fixed 确切的，确定的
era
n. 1. 时代；年代
2. 纪元
Phrases and Expressions
warn of /about
give warning or advice concerning (sth. such as a danger) 就…提出警告
result from
be the result of; happen because of 缘于，发自
dry up
(cause to) become completely dry （使）干涸
warn against
advise (sb.) to avoid 警告（…）不要，提醒（…）提防
on the rise
在增长；在上涨
in the form of
以…的形式
heat up
become warm or hot 变暖，变热
pass through 穿越；经过
hold in
把…控制住
shut in
keep or hold by closing 围住；笼罩
due to
caused by 由于
ups and downs
起伏
worst of all
最糟糕的是
by comparison
when compared 比较起来
even so
though that is true 尽管如此
explain away
account for; give an excuse for 解释；为…辩解
keep an eye open for
watch for; be careful to notice 严密注视；留心看着
Proper Names
Kevin McKean
凯文·麦基恩（人名）
Venus
金星
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