高二人教新課標(biāo)選修6 unit 4 課文翻譯

1、reading 1the earth is becoming warmer but does it matter?www.2abc8.coduring the 20th century the temperature of the earth rose about one degree fahrenheit. that probably does not seem much to you or me, but it is a rapid increase when compared to other natural changes. so how has this come about and

2、 does it matter? earth cares sophie armstrong explores these questions.there is no doubt that the earth is becoming warmer (see graph 1) and that it is human activity that has caused this global warming rather than a random but natural phenomenon.all scientists subscribe to the view that the increas

3、e in the earths temperature is due to the burning of fossil fuels like coal, natural gas and oil to produce energy. some byproducts of this process are called greenhouse gases, the most important one of which is carbon dioxide. dr janice foster explains: there is a natural phenomenon that scientists

4、 call the greenhouse effect. this is when small amounts of gases in the atmosphere, like carbon dioxide, methane and water vapour, trap heat from the sun and therefore warm the earth. without the greenhouse effect, the earth would be about thirty-three degrees celsius cooler than it is. so, we need

5、those gases. the problem begins when we add huge quantities of extra carbon dioxide into the atmosphere. it means that more heat energy tends to be trapped in the atmosphere causing the global temperature to go up.www.2abc8.cowe know that the levels of carbon dioxide have increased greatly over the

6、last 100 to 150 years. it was a scientist called charles keeling, who made accurate measurements of the amount of carbon dioxide in the atmosphere from 1957 to 1997. he found that between these years the carbon dioxide in the atmosphere went up from around 315 parts to around 370 parts per million (

7、see graph 2).all scientists accept this data. they also agree that it is the burning of more and more fossil fuels that has resulted in this increase in carbon dioxide. so how high will the temperature increase go? dr janice foster says that over the next 100 years the amount of warming could be as

8、low as 1 to 1,5 degrees celsius, but it could be as high as 5 degrees.however, the attitude of scientists towards this rise is completely different. on the one hand, dr foster thinks that the trend which increases the temperature by 5 degrees would be a catastrophe. she says, we cant predict the cli

9、mate well enough to know what to expect, but it could be very serious. others who agree with her think there may be a rise of several metres in the sea level, or predict severe storms, floods, droughts, famines, the spread of diseases and the disappearance of species. on the other hand, there are th

10、ose, like george hambley, who are opposed to this view, believe that we should not worry about high levels of carbon dioxide in the air. they predict that any warming will be mild with few bad environmental consequences. in fact, hambley states, more carbon dioxide is actually a positive thing. it w

11、ill make plants grow quicker; crops will produce more; it will encourage a greater range of animals all of which will make life for human beings better.www.2abc8.cogreenhouse gases continue to build up in the atmosphere. even if we start reducing the amount of carbon dioxide and other greenhouse gas

12、es, the climate is going to keep on warming for decades or centuries. no one knows the effects of global warming. does that mean we should do nothing? or, are the risks too great?第四單元 全球在變暖www.2abc8.co 全球在變暖一一這會帶來什么影響嗎? 在20世紀(jì)期間,地球溫度大約升了華氏1度。這個(gè)數(shù)值對你我來說很可能是無所謂的,但是跟其他自然變化相比較而言,這卻是一種快速的增長。那么,這種溫度的增長是怎么產(chǎn)生

13、的呢?會產(chǎn)生什么影響 呢? “關(guān)愛地球”組織的索菲阿姆斯特朗就在探究這些問題。毫無疑問,地球是在變暖(見表一,略) ,而地球變暖正是人類活動導(dǎo)致而成的,并非是一種無規(guī)律的自然現(xiàn)象。所有的科學(xué)家贊同這種觀點(diǎn):人們?yōu)榱松a(chǎn)能量而燃燒化石燃料(如煤、天然氣和石油等) ,從而引起了地球溫度的升高。這個(gè)升溫過程的一些副產(chǎn)品就叫做溫室氣體,其中最重要的就是二氧化碳。賈尼絲福斯特博士解釋說:www.2abc8.co有一種科學(xué)家稱之為溫室效應(yīng)的自然現(xiàn)象。這種現(xiàn)象發(fā)生在大氣層中少量的氣體(如二氧化碳、甲皖、水蒸汽等)吸收太陽的熱量,因而使地球變暖的時(shí)候。如果沒有這種溫室效應(yīng),地球的溫度將比現(xiàn)在的溫度還要低33攝

14、氏度左右。因此,我們需要這些氣體。當(dāng)我們在大氣層中增加了大量額外的二氧化碳時(shí),問題就來了。這意味著更多的熱量被困在大氣層中,從而引起全球溫度上升。我們知道,在過去100-150年期間,二氧化碳的含量急劇增加了。有一位名叫查爾斯基林的科學(xué)家曾經(jīng)把1957-1997年期間大氣層中二氧化碳的含量作了精確的統(tǒng)計(jì)。他發(fā)現(xiàn),在這些年里,大氣層中 的二氧化碳含量從315/1000 000上升到370/1000 0000 (見表二,略)所有科學(xué)家都接受這個(gè)數(shù)據(jù)。他們還贊同下述觀點(diǎn),正是由于越來越多燃燒化石燃料導(dǎo)致了二氧化碳的增加。那么氣溫會升到多高?福斯特博士說,在今后的100年里,全球變暖的量可能低到1-1

15、.5攝氏度, 但是也有可能高達(dá)5攝氏度。www.2abc8.co然而,科學(xué)家們在對待升溫的態(tài)度上卻是大不相同的。一方面,福斯特博士認(rèn)為氣溫升高5度的趨勢可能是一場大災(zāi)難,她說對于未來的氣候,我們不可能作出精確的預(yù)測,但是那時(shí)的天氣可能是很糟糕的。同意她的觀點(diǎn)的其他科學(xué)家認(rèn)為,全球變暖會導(dǎo)致海平面上升好幾米:也有人預(yù)言會出現(xiàn)嚴(yán)重的風(fēng)暴、洪澇、干旱、饑荒、疫病和物種的絕滅。在另一方面,還有一些人,像科學(xué)家喬治漢布利,反對上面的觀點(diǎn),他們認(rèn)為我們不必?fù)?dān)心空氣中會有高含量的二氧化碳。他們預(yù)言說,變暖的情況不會很嚴(yán)重,對環(huán)境的影響也不會太壞。漢布利實(shí)際上是這樣說的:二氧化碳含量的增加實(shí)際上是件好事,它使植物成長更快,莊稼產(chǎn)量更高,還會促進(jìn)動物的生長一一所有這些都能改善人類的生活。 溫室氣體繼續(xù)在大氣層中聚集。即使我們