Variations in the Climate
gruntOne 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 immenly 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 oppod 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 u proxy records.
Over long periods of time, substances who physical and chemical properties change with the ambien
t climate at the time can be deposited in a systematic way to provide a continuous record of changes in tho properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the obrved 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 diments in Western Europe, ocean floor diment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While the 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 the records can provide a measure of its true variability, it should at least indicate how all the natural caus of climate change have combine
d. The 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 arin from volcanic activity, solar activity, and, possibly, human activities.
One way to estimate how all the various process leading to climate variability will combine is by using computer models of the global climate. They can do only so much to reprent 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 itlf, there is the added factor of external influences, such as volcanoes and solar activity. There is a growing body of opinion that both the physical variations have a measurable impact on the climate. Thus we need to be able to include the in our deliberations. Some current analys conclude that volcanoes and solar activity explain quite a considerable amount of the obrved variability in the period from the venteenth to the early twentieth centuries, but that they cannot be invoked to explain the rapid warming in recent decades.
去角质的使用方法Paragraph 1: 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 immenly 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 oppod to being the result of human activities.
1. According to paragraph 1, which of the following must we find out in order to determine the impact of human activities upon climate?pda是什么
○ The major changes in climate over the past millennia英语缩写词
○ The degree to which the climate varies naturally
○ The best method for measuring climatic change
○ The millennium when humans began to interfere with the climate
Paragraph 2: 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 u proxy records.
期颐怎么读2. According to paragraph 2, an advantage of proxy records over instrumental records is that
○ they are more-reliable measures of climatic variability in the past century
○ they provide more-accurate measures of local temperatures
○ they provide information on climate fluctuations further back in time
○ they reveal information about the human impact on the climate
4级成绩Paragraph 3:mink是什么颜色
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 diments in Western Europe, ocean floor diment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While the 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.
of the ntences below best express the esntial information in the
information.
○ Becau physical and chemical properties of substances are unchanging, they are uful records of climate fluctuations over time.
○ For hundreds or thousands of years, people have been obrving changes in the chemical and physical properties of substances in order to infer climate change.
○ Becau it takes long periods of time for the climate to change, systematic changes in the properties of substances are difficult to obrve.
○ Changes in systematically deposited substances that are affected by climate can indicate climate variations over time.
4. According to paragraph 3, scientists are able to reconstruct proxy temperature records by
○ studying regional differences in temperature variations
○ studying and dating changes in the properties of substances
○ obrving changes in prent day climate conditions
○ inferring past climate shifts from obrvations of current climatic changes
Paragraph 4: What the proxy records make abundantly clear is that there have been significant natural
relative stability of the climate in the past 10,000 years (the Holocene period).
面板英文in the passage is clost in meaning toscrotum>抛物线的性质
○ noticeable
○ confusing
○ true
○ unlikely
Paragraph 3: Over long periods of time, substances who physical and chemical properties change with
changes in tho properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the obrved 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 diments in Western Europe, ocean floor diment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While the 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.
Paragraph 4: 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).
6. According to paragraphs 3 and 4, proxy data have suggested all of the following about the climate EXCEPT:
○ Regional climates may change overtime.
○ The climate has changed very little in the past 10,000 years.
○ Global temperatures vary more than regional temperatures.
○ Important natural changes in climate have occurred over large timescales.
Paragraph 5: To the extent that the coverage of the global climate from the records can provide a measure of its true variability, it should at least indicate how all the natural caus of climate change have
of the oceans, changes in the land surfaces, and the extent of ice and snow. Also included will be any variations that have arin from volcanic activity, solar activity, and, possibly, human activities.
7. The in the passage is clost in meaning to
○ dramatic
○ important
○ unpredictable
○ common
8. All of the following are mentioned in paragraph 5 as natural caus of climate change EXCEPT
○ atmospheric changes
○ the slow movement of landmass
○ fluctuations in the amount of ice and snow
○ changes in ocean activity
Paragraph 6: One way to estimate how all the various process leading to climate variability will combine is by using computer models of the global climate. They can do only so much to reprent 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.
9. According to paragraph 6, which of the following is true of computer models of the global climate?
○ The information they produce is still limited.
○ They are currently most uful in understanding past climatic behaviors.
○ They allow rearchers to interpret the data obtained from proxy records.
○ They do not provide information about regional climates.
Paragraph 7: In addition to the internal variability of the global climate system itlf, there is the added factor of external influences, such as volcanoes and solar activity. There is a growing body of opinion that
considerable amount of the in the period from the venteenth to the early twentieth
10. The word in the passage is clost in meaning to
○ records
○ discussions
○ results
○ variations
11. The in the passage is clost in meaning to
○ demonstrated
○ called upon
○ supported
○ expected
12. What is the author's purpo in prenting the information in paragraph 7?
○ To compare the influence of volcanoes and solar activity on climate variability with the influence of factors external to the global climate system
○ To indicate that there are other types of influences on climate variability in addition to tho previously discusd
○ To explain how external influences on climate variability differ from internal influences
○ To argue that the rapid warming of Earth in recent decades cannot be explained
Paragraph 7: In addition to the internal variability of the global climate system itlf, there is the added factor of external influences, such as volcanoes and solar activity. ■There is a growing body of opinion that
