TPO10托福阅读Passage2 Variations in the Climate文本+题目原文+答案解析

Variations in the Climate

One of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention. We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities.

Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records.

Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature variations can occur on a global scale, there are nonetheless some intriguing differences, which suggest that the pattern of temperature variations in regional climates can also differ significantly from each other.

What the proxy records make abundantly clear is that there have been significant natural changes in the climate over timescales longer than a few thousand years. Equally striking, however, is the relative stability of the climate in the past 10.000 years (the Holocene period).

To the extent that the coverage of the global climate from these records can provide a measure of its true variability, it should at least indicate how all the natural causes of climate change have combined. These include the chaotic fluctuations of the atmosphere, the slower but equally erratic behavior of the oceans, changes in the land surfaces, and the extent of ice and snow. Also included will be any variations that have arisen from volcanic activity, solar activity, and, possibly, human activities.

One way to estimate how all the various processes leading to climate variability will combine is by using computer models of the global climate. They can do only so much to represent the full complexity of the global climate and hence may give only limited information about natural variability. Studies suggest that to date the variability in computer simulations is considerably smaller than in data obtained from the proxy records.

In addition to the internal variability of the global climate system itself, there is the added factor of external influences, such as volcanoes and solar activity.  [■] There is a growing body of opinion that both these physical variations have a measurable impact on the climate.  [■] Thus we need to be able to include these in our deliberations. [■]  Some current analyses conclude that volcanoes and solar activity explain quite a considerable amount of the observed variability in the period from the seventeenth to the early twentieth centuries, but that they cannot be invoked to explain the rapid warming in recent decades. [■] 

TPO10托福阅读Passage2Variations in the Climate题目

Question 1 of 14：According to paragraph 1, which of the following must we find out in order to determine the impact of human activities upon climate?

A. The major changes in climate over the past millennia

B. The degree to which the climate varies naturally

C. The best method for measuring climatic change

D. The millennium when humans began to interfere with the climate

Question 2 of 14：According to paragraph 2, an advantage of proxy records over instrumental records is that

A. they are more-reliable measures of climatic variability in the past century

B. they provide more-accurate measures of local temperatures

C. they provide information on climate fluctuations further back in time

D. they reveal information about the human impact on the climate

Question 3 of 14：Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

A. Because physical and chemical properties of substances are unchanging, they are useful records of climate fluctuations over time.

B. For hundreds or thousands of years, people have been observing changes in the chemical and physical properties of substances in order to infer climate change.

C. Because it takes long periods of time for the climate to change, systematic changes in the properties of substances are difficult to observe.

D. Changes in systematically deposited substances that are affected by climate can indicate climate variations over time.

Question 4 of 14：According to paragraph 3, scientists are able to reconstruct proxy temperature records by

A. studying regional differences in temperature variations

B. studying and dating changes in the properties of substances

C. observing changes in present day climate conditions

D. inferring past climate shifts from observations of current climatic changes

Question 5 of 14：The word “striking ” in the passage is closest in meaning to

A. noticeable

B. confusing

C. true

D. unlikely

Question 6 of 14：According to paragraphs 3 and 4, proxy data have suggested all of the following about the climate EXCEPT:

A. Regional climates may change overtime.

B. The climate has changed very little in the past 10,000 years.

C. Global temperatures vary more than regional temperatures.

D. Important natural changes in climate have occurred over large timescales.

Question 7 of 14：The word “erratic ” in the passage is closest in meaning to

A. dramatic

B. important

C. unpredictable

D. common

Question 8 of 14：All of the following are mentioned in paragraph 5 as natural causes of climate change EXCEPT

A. atmospheric changes

B. the slow movement of landmasses

C. fluctuations in the amount of ice and snow

D. changes in ocean activity

Question 9 of 14：According to paragraph 6, which of the following is true of computer models of the global climate?

A. The information they produce is still limited.

B. They are currently most useful in understanding past climatic behaviors.

C. They allow researchers to interpret the data obtained from proxy records.

D. They do not provide information about regional climates.

Question 10 of 14：The word “deliberations ” in the passage is closest in meaning to

A. records

B. discussions

C. results

D. variations

Question 11 of 14: The word “invoked ” in the passage is closest in meaning to

A. demonstrated

B. called upon

C. supported

D. expected

Question 12 of 14: What is the author's purpose in presenting the information in paragraph 7?

A. To compare the influence of volcanoes and solar activity on climate variability with the influence of factors external to the global climate system

B. To indicate that there are other types of influences on climate variability in addition to those previously discussed

C. To explain how external influences on climate variability differ from internal influences

D. To argue that the rapid warming of Earth in recent decades cannot be explained

Question 13 of 14: Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit?

Indeed, the contribution of volcanoes and solar activity would more likely have been to actually reduce the rate of warming slightly..

Question 14 of 14: Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that not presented in the passage or are minor ideas in the passage. This question is worth 2 points.A number of different and complex factors influence changes in the global climate over long periods of time.

A.In the absence of instrumental records, proxy data allow scientists to infer information about past climates.

B.Scientists see a consistent pattern in the global temperature variations that have occurred in the past.

C.Computer models are used to estimate how the different causes of climate variability combine to account for the climate variability that occurs.

D.Scientists have successfully separated natural climate variation from changes related to human activities.

E.Scientists believe that activities outside the global climate system, such as volcanoes and solar activity may have significant effects on the system.

F. Scientists have concluded that human activity accounts for the rapid global warming in recent decades.

TPO10托福阅读Passage2Variations in the Climate解析

Question 1 of 14

正确答案：B

题目解析：B 以human activities做关键词定位至第一句，说在判断人类对气候的影响之前必须断定自然的影响，所以B正确。A和D都提到了millenium，这是这句话没说到的，所以两个都错;C的best method也没说。

Question 2 of 14

正确答案：C

题目解析：C 以proxy records做关键词定位至最后一句，a better picture of fluctuations further back in time，指的是时间更久远，所以答案是C，这个比较简单，跟文章说的完全一样。

Question 3 of 14

正确答案：D

题目解析：D, 去掉定语从句后，原文变成substance can be deposited to record blabla，A和C的因果关系是硬造出来的，原文没有，错;而且A说unchanging，原文是变化，A说反;B原文是record，不是infer，B错;而且C说difficult to observe，原文没说，错;D正确。

Question 4 of 14

正确答案：B

题目解析：B 以peoxy temperature records做关键词定位至第四句，本句说了很多重建温度的很多方法，无论是冰川，沉积物还是碳酸盐，都属于substance，所以B正确，其他都没说。

Question 5 of 14

正确答案：A

题目解析：striking: 显著的，吸引人的。A是显著的，值得注意的;B是令人困惑的;C是正确的;D是不可能的。所以noticeable引人注意的正确。对应原文：Equally striking, however, is the relative stability of the climate in the past 10,000 years (the Holocene period).句子一开始就说同样striking的是，说明之前一定有一个很striking的东西。前一句说有significant natural changes，所以significant的同义词就是striking。

Question 6 of 14

正确答案：C

题目解析：第四段很短，快速读完。A和D对应第四段第一句：What the proxy records make abundantly clear is that there have been significant natural changes in the climate over timescales longer than a few thousand years.说气候在一段时间内会变化;第二句里的stability对应B中的changed little：Equally striking, however, is the relative stability of the climate in the past 10.000 years (the Holocene period).所以这B选项都正确，不选;只有C的比较关系在原文没说，所以C是答案。

Question 7 of 14

正确答案：C

题目解析：erratic: 古怪的，不稳定的，飘忽不定的。A是戏剧的，引人注意的;B是重要的;C是不可预测的;D是常见的，普通的。所以C，unpredictable正确。对应原文：These include the chaotic fluctuations of the atmosphere, the slower but equally erratic behavior of the oceans, changes in the land surfaces, and the extent of ice and snow.原句说equally erratic，所以之前一定得有一个跟erratic意思差不多的词，之前有chaotic fluctuation，所以erratic和chaotic是同义词，chaotic混乱的，备选项中只unpredictable跟这个意思靠谱，ABD都不对。

Question 8 of 14

正确答案：B

题目解析：B EXCEPT题，排除法。A对应第二句的fluctuation of the atmosphere，正确，不选;B与原文的changes in land surface有明显区别，错，选;C对应原文的extent of ice and snow，正确，不选;D对应原文的erratic behavior of the ocean，正确，不选。

Question 9 of 14

正确答案：A

题目解析：A 以computer models做关键词定位至第一句，但这句只是在单纯重复问题，所以往下看。说computer model能给出气候的complexity，并且给出limited info，只有A答案说到limited info，所以A正确。其他都没说。

Question 10 of 14

正确答案：B

题目解析：deliberation: 深思熟虑，审议。A是记录;B是讨论;C是结果;D是变化。所以B的discussions正确。对应原文：Thus we need to be able to include these in our deliberations.本句以thus开头，说明这句话是一个结果，造成结果的原因是越来越多的人认为这些物理上的变化对气候的影响是可计算的，因此在我们的什么当中必须包含这些，A记录和C结果都没法被主观的东西包含的，所以错;我们的变化完全不靠谱。

Question 11 of 14

正确答案：B

题目解析：invoke: 引起，求助。in表示内部，voke表示声音，所以B的call upon引起正确。A是展示;C是支持;D是期盼。对应原文：Some current analyses conclude that volcanoes and solar activity explain quite a considerable amount of the observed variability in the period from the seventeenth to the early twentieth centuries, but that they cannot be invoked to explain the rapid warming in recent decades.说现在的分析能够得出一些结论，但这些结论不能什么解释气候快速变暖。demonstrate和support错，即使支持解释和展示解释是对的，也不能用被动态;expect代入是对的，所以只能靠认识了。

Question 12 of 14

正确答案：B

题目解析：B，问整段的关注第一句，这句说除了internal之外，还有external，是一个典型的承上启下的句子，启下的才是这段要说的，也就是external的部分，所以答案是B。A和C都说比较，而原文根本没有比较;D错因为原文没有argue。

Question 13 of 14

正确答案：D

题目解析：D 三个过渡点，名词volcanoes and solar activity，warming和副词indeed，根据volcanoes and solar activity确定C或者D正确;indeed有转折意思，前文说快速warming，紧接着就转折说应该是减少warming的，所以正确答案是D。

Question 14 of 14

正确答案：ACE

题目解析：A.C.E In the absence选项对应原文第二段的首末句，正确。Scientists see选项和第三段的尾句相反，错误，不选。Computers选项对应原文第六段，正确。Scientists have successfully选项与第一段的首句相反，不选。Scientists believe选项对应原文第七段的首句，正确。Scientists have concluded选项原文没说，不选。

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