Reading Comprehension Sample Passage Pair

Passage A 

In January 1995 a vast section of ice broke off the Larsen ice shelf in Antarctica. While this occurrence, the direct result of a regional warming trend that began in the 1940s, may be the most spectacular manifestation yet of serious climate changes occurring on the planet as a consequence of atmospheric heating, other symptoms—more intense storms, prolonged droughts, extended heat waves, and record flooding—have been emerging around the world for several years. 

According to scientific estimates, furthermore, sea-level rise resulting from global warming will reach 3 feet (1 meter) within the next century. Such a rise could submerge vast coastal areas, with potentially irreversible consequences. 

Late in 1995 the Intergovernmental Panel on Climate Change (IPCC) reported that it had detected the “fingerprint” of human activity as a contributor to the warming of the earth’s atmosphere. Furthermore, panel scientists attributed such warming directly to the increasing quantities of carbon dioxide released by our burning of fossil fuels. The IPCC report thus clearly identifies a pattern of climatic response to human activities in the climatological record, thereby establishing without doubt that global warming can no longer be attributed solely to natural climate variability.

Passage B

Over the past two decades, an extreme view of global warming has developed. While it contains some facts, this view also contains exaggerations and misstatements, and has sometimes resulted in unreasonable environmental policies.

According to this view, global warming will cause the polar ice to melt, raising global sea levels, flooding entire regions, destroying crops, and displacing millions of people. However, there is still a great deal of uncertainty regarding a potential rise in sea levels. Certainly, if the earth warms, sea levels will rise as the water heats up and expands. If the polar ice caps melt, more water will be added to the oceans, raising sea levels even further. There is some evidence that melting has occurred; however, there is also evidence that the Antarctic ice sheets are growing. In fact, it is possible that a warmer sea surface temperature will cause more water to evaporate, and when wind carries the moisture-laden air over the land, it will precipitate out as snow, causing the ice sheets to grow. Certainly, we need to have better knowledge about the hydrological cycle before predicting dire consequences as a result of recent increases in global temperatures.

This view also exaggerates the impact that human activity has on the planet. While human activity may be a factor in global warming, natural events appear to be far more important. The 1991 eruption of Mount Pinatubo in the Philippines, for example, caused a decrease in the average global temperature, while El Niño, a periodic perturbation in the ocean’s temperature and circulation, causes extreme global climatic events, including droughts and major flooding. Of even greater importance to the earth’s climate are variations in the sun’s radiation and in the earth’s orbit. Climate variability has always existed and will continue to do so, regardless of human intervention. 

Question 8

Which one of the following questions is central to both passages? 

A. How has an increase in the burning of fossil fuels raised the earth’s temperature? 

B. To what extent can global warming be attributed to human activity? 

C. What steps should be taken to reduce the rate of global warming? 

D. What kinds of human activities increase the amount of carbon dioxide in the atmosphere? 

E. To what extent is global warming caused by variations in the sun’s radiation and the earth’s orbit?

Question 9 

Which one of the following is mentioned in passage B but not in passage A as a possible consequence of global warming? 

A. an increase in the size of the Antarctic ice sheet 

B. a decrease in the amount of snowfall 

C. a falling of ocean sea levels 

D. an increase in the severity of heat waves 

E. an increase in the frequency of major flooding 

Question 10 

The authors of the two passages would be most likely to disagree over 

A. whether or not any melting of the polar ice caps has occurred 

B. whether natural events can cause changes in global climate conditions 

C. whether warmer air temperatures will be likely to raise oceanic water temperatures 

D. the extent to which natural climate variability is responsible for global warming 

E. the extent to which global temperatures have risen in recent decades 

Question 11

Which one of the phenomena cited in passage A is an instance of the kind of “evidence” referred to in the middle of the second paragraph of passage B? 

A. the breaking off of part of the Larsen ice shelf in 1995 

B. higher regional temperatures since the 1940s 

C. increases in storm intensities over the past several years 

D. the increased duration of droughts in recent years 

E. the increased duration of heat waves over the past decade 

Question 12 

The author of passage B would be most likely to make which one of the following criticisms about the predictions cited in passage A concerning a rise in sea level? 

A. These predictions incorrectly posit a causal relationship between the warming of the earth and rising sea levels. 

B. These predictions are supported only by inconclusive evidence that some melting of the polar ice caps has occurred. 

C. These predictions exaggerate the degree to which global temperatures have increased in recent decades. 

D. These predictions rely on an inadequate understanding of the hydrological cycle. 

E. These predictions assume a continuing increase in global temperatures that may not occur. 

Question 13 

The relationship between passage A and passage B is most analogous to the relationship between the documents described in which one of the following? 

A. a research report that raises estimates of damage done by above-ground nuclear testing; an article that describes practical applications for nuclear power in the energy production and medical fields 

B. an article arguing that corporate patronage biases scientific studies about the impact of pollution on the ozone layer; a study suggesting that aerosols in the atmosphere may counteract damaging effects of atmospheric carbon dioxide on the ozone layer 

C. an article citing evidence that the spread of human development into pristine natural areas is causing catastrophic increases in species extinction; an article arguing that naturally occurring cycles of extinction are the most important factor in species loss 

D. an article describing the effect of prolonged drought on crop production in the developing world; an article detailing the impact of innovative irrigation techniques in water-scarce agricultural areas 

E. a research report on crime and the decline of various neighborhoods from 1960 to 1985; an article describing psychological research on the most important predictors of criminal behavior 

Question 14 

Which one of the following most accurately describes the relationship between the argument made in passage A and the argument made in passage B? 

A. Passage A draws conclusions that are not based on hard evidence, while passage B confines itself to proven fact. 

B. Passage A relies on evidence that dates back to the 1940s, while passage B relies on much more recent evidence. 

C. Passage A warns about the effects of certain recent phenomena, while passage B argues that some inferences based on those phenomena are unfounded. 

D. Passage A makes a number of assertions that passage B demonstrates to be false. 

E. Passage A and passage B use the same evidence to draw diametrically opposed conclusions.