In the atmosphere, carbon dioxide acts rather like a one-way mirror -- the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping.
大氣中二氧化碳的作用類似於單向反射鏡——如溫室的玻璃屋頂，允許太陽光線的進入，同時又防止內部熱量的散失。
According to a weather expert’s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several metres and severely flooding coastal cities.
根據氣象專家的預測，若人類繼續以當前的速度燃燒燃料，則2050年的大氣層會比現在溫度升高3℃。一旦這種溫室效應真的發生，則極地冰蓋會開始融化，從而使海面上升達幾米，沿線城市出現嚴重洪水災害。
Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of earth’s chief food-growing zones.
除此之外，大氣溫度的上升會使北半球的氣候產生巨大變化，可能從而導致世界主要產糧區的改變。
In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet.
過去人們主要關注人為造成的全球變暖對北極的影響，因為南極圈比北極圈冷得多，且冰層也厚得多，
But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming: in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.
但現在，氣候專家開始把更多的注意力放到了西南極圈─—因為幾度的升溫（換言之，未來五十年燃料燃燒所造成的升溫）足可以影響該地區。
Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.
衛星圖像表明：南極圈中大片區域已經開始消失。現有證據表明：溫室效應已經發生。這與二氧化碳能使地球變暖的理論相符。
However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling.
但是，燃料燃燒最多的北半球溫度不升反降。
Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has most effect on the weather?
對此，科學家得出的結論是：迄今為止，自然因素對天氣的影響勝過人為因素。問題是，哪種自然因素對天氣的影響最大。
One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and 「cold」 spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days, it presents hotter or 「colder」 faces to the earth, and different aspects to different parts of the earth.
一種可能是太陽行為的變化。某一研究站的氣象學家已對太陽的熱點和「冷點（相對較冷的地方）」進行了研究。太陽旋轉時，以27.5天為周期向地球的不同地方展示其熱點或「冷點」的不同方面。
This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward.
這似乎對地球大氣壓力的分布有相當大的影響，從而影響風流。同時，太陽也在做長期的變化：它的熱量釋放呈升——降交替變化，最近呈下降趨勢。
Scientists are now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not.
科學家們現在發現了太陽——天氣互動模式和實際氣候幾千年間的變化（包括最後的冰川時代）之間的聯繫。問題是: 基於這種模式的預測，世界現在應該正在進入新的冰川時代，而實際上並沒有。
One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia (慣性) of the earth’s climate. If this is right, the warming effect of carbon dioxide might thus be serving as a useful counter-balance to the sun’s diminishing heat.
對這個理論難題的解決方法是：假定太陽效應克服地球氣候的慣性效應需要幾千年時間。若此假定正確，則二氧化碳的溫室效應會有助於抵消太陽熱量的減少趨勢。
14. It can be concluded that a concentration of carbon dioxide in the atmosphere would.
[A] prevent the sun’s rays from reaching the earth’s surface
[B] mean a warming up in the Arctic
[C] account for great changes in the climate in the northern hemisphere
[D] raise the temperature of the earth’s surface
[分析] 本題考核知識點：細節推理題。
第一段將二氧化碳在大氣中的作用類比溫室的玻璃屋頂：允許陽光進入，並阻止內部熱量的逃逸，（其結果是地球表面溫度上升）。第二段首句則直接指出燃燒產生的二氧化碳會使大氣溫度上升。第四段指出：南極氣候變化證明了二氧化碳使地球變暖的理論。所以，[D]為正確選項。
[A]和第一段內容相反。第五段說明，北半球（包括北極圈）的氣溫在下降，所以，從文中無法推知[B]。[C]的錯誤在於其片面性。第五段指出：產生二氧化碳最多的北半球溫度不升反降是因為：自然因素對北半球氣候的影響大於人為因素，所以，北半球氣候的變化是自然因素和人為因素作用的共同結果。
15. The article was written to explain.
[A] the greenhouse effect
[B] the solar effects on the earth
[C] the models of solar-weather interactions
[D] the causes affecting weather
[分析] 本題考核知識點：文章主旨題。
解答文章主旨題需要對全文的綜合理解。本文第一到四段為人為因素（溫室效應）對天氣的影響。第五至六段為自然因素（太陽行為的變化）對天氣的影響。最後一段為人為因素和自然因素對地球氣候的共同作用。所以，[D]為最恰當選項。
[A]、[B]、[C] 的錯誤在於其片面性。[A]只是影響氣候的人為因素，而[B]、[C]只涉及了影響氣候的自然因素。
16. Although the fuel consumption is greater in the northern hemisphere, temperatures there seem to be falling. This is.
[A] mainly because the levels of carbon dioxide are rising
[B] possible because the ice caps in the poles are melting
[C] exclusively due to the effect of the inertia of the earth’s climate
[D] partly due to variations in the output of solar energy
[分析] 本題考核知識點：因果細節題。
第五段第二句指出，北半球燃料燃燒產生二氧化碳最多，氣溫卻不升反降是因為：迄今為止，自然因素的影響勝過人為因素。第六段進一步指出，對地球氣候變化影響最大的「自然因素」是太陽行為的變化：太陽的運轉影響風流（wind circulaltion）；太陽能量釋放呈周期性變化。所以，太陽能釋放的變化是北半球氣溫下降的原因之一，[D]為正確選項。
二氧化碳含量上升導致的結果是氣溫上升，所以[A]不正確。[B]無中生有：文中沒有提及極地冰蓋融化和北半球氣溫下降之間的聯繫，而且根據常識也可排除。[C]的錯誤在於：誤把抑制因素當成了形成因素。從第五、六段可知，北半球溫度下降的原因是自然因素（尤其是太陽行為）的影響。而最後一段倒數第二句指出：地球氣候的慣性與太陽效應是相反的過程，因此它應對地球變冷起抑制作用。另外，exclusively 的過於絕對也暗示這不是正確選項。但近年的考題已經在避免留給考生這樣的線索。
17. On the basis of their models, scientists are of the opinion that.
[A] the climate of the world should be becoming cooler
[B] it will take thousands of years for the inertia of the earth’s climate to take effect
[C] the man-made warming effect helps to increase the solar effects
[D] the new Ice Age will be delayed by the greenhouse effect
[分析]本題考核知識點：文中人物觀點推理題。
第七段第二句說明：科學家們基於太陽——天氣互動模式，預測出世界現在應該正在進入冰川時代，所以[A]為正確選項。
[B]的錯誤在於對第七段第三句的理解錯誤。該句說明的是「太陽效應克服地球氣候的慣性效應」，而非「地球氣候的慣性發生效應」。[C]和原文內容相反。本文最後一句說明：目前二氧化碳的溫室效應在對太陽效應產生抵消作用（counterbalance）。第七段第三句說明：延遲新的冰川時代的主要因素是地球氣候的慣性作用，因此[D]不正確。
18. If the assumption about the delay of a new Ice Age is correct,.
[A] the best way to overcome the cooling effect would be to burn more fuels
[B] ice would soon cover the northern hemisphere
[C] the increased levels of carbon dioxide in the atmosphere could warm up the earth even more quickly
[D] the greenhouse effect could work to the advantage of the earth
[分析]本題考核知識點：文中細節推理題。
文中最後一句說明：若此假說（關於冰川時代的延遲）正確，則溫室效應可以對地球進入新的冰川時代起到遏制作用，這無疑是有利於地球的一面。所以，[D]為正確選項。
[A]過度引申，文中僅僅提到大氣溫度上升有助於抵消太陽熱量的減少，但燃燒燃料是否最好文中未提。[B]錯誤在於：北半球被冰覆蓋不是冰川時代延遲的結果，而是冰川時代到來的後果。[C]屬邏輯錯誤：冰川時代的延遲雖然與二氧化碳的溫室效有關，但地球是否會「更快（even more）」變暖則文中未提。