Increases in the amount of carbon dioxide (CO2) and other trace gases

Question

Increases in the amount of carbon dioxide (CO2)
and other trace gases in the Earth’s atmosphere can
contribute to what has been called greenhouse
warming, because those compounds allow the Sun’s
  (5)   energy to reach the surface of the Earth, thereby
warming it, but prevent much of that energy from
being reradiated to outer space. Measuring devices
set up at several locations around the world have
revealed a 20 percent increase in atmospheric CO2
  (10)   over the course of the past century—from 290 parts
per million in 1880 to 352 parts per million in 1989.
Several studies agree that it is plausible that the
CO2 content of the atmosphere may well double
from its 1880 level by around the middle of the
  (15)   twenty-first century.

To project how much the global temperature will
increase in response to a doubling of atmospheric
CO2 should be simple: since the CO2 content has
increased by about 20 percent over the past century,
  (20)   we should be able to observe the increases in global
temperature during the same period and base
future projections on that data. The prevailing view
is that the climatic record over the past century for
the entire globe reveals a net increase in
  (25)   temperature ranging from 0.5 to 1.0 degree
Fahrenheit (approximately 0.25 to 0.5 degrees
Celsius). But set against this conclusion is the fact
that data gathered over the past century in North
America, where observations are numerous and
  (30)   accurate, does not confirm such an increase. And
even if the temperature rise is real, another puzzle
remains: is the rise in global temperatures a natural
fluctuation or a result of the increase in greenhouse
gases?

(35)   Because of inconclusive data and the complexity
of the problem, some scientists predict an increase
as small as two degrees Fahrenheit (one degree
Celsius) in the average global temperature over the
next half century, whereas others predict increases
  (40)   of up to nine degrees Fahrenheit (five degrees
Celsius). It makes a great difference whether the
actual increase is at the low or high end of this
range. Although human beings are probably
resilient enough to adapt to the effects of an
  (45)   increase of approximately two degrees Fahrenheit
(one degree Celsius), an increase of nine degrees
Fahrenheit (five degrees Celsius) is believed to be
the difference in temperature that separates the
end of the last great ice age, 12,000 years ago, from
  (50)   the present.

In light of such uncertainty, the wisest policy is
not to forestall action. Steps that make sense for
economic or environmental reasons besides
greenhouse warming, such as replacing fossil-fuel
  (55)   energy with solar energy, could be taken first,
whether or not climate warming is taking place.
Then, as scientific knowledge grows and
uncertainties are reduced, more costly measures
could be taken, if warranted, hence closely tying
  (60)   policy decisions to the latest information available.
Scientists and others have aptly called this type of
action a “no regrets” policy.    1 
 1. Which one of the following statements best expresses the main idea of the passage?

(A) Approaching the problem of greenhouse warming with a “no regrets” policy encourages government agencies to implement affordable but most likely ineffective measures.
(B) Inconclusive data concerning the rise in global temperature over the next half century suggests that politicians should wait until all uncertainties are resolved before taking action.
(C) Costly measures must be taken soon to prevent further increases in greenhouse gases and thus a dangerous rise in global temperatures.
(D) Given the lack of agreement about the effects of greenhouse gases on global temperature, the best policy is to implement sensible measures now and respond to new scientific knowledge as it appears.
(E) Scientists would be able to provide a more accurate estimate of the probable effects of greenhouse warming over the next half century if politicians took steps now to eliminate other environmental problems that contribute to global warming.

2 
 2. The passage suggests that a rise in global temperature over the next half century, if it occurs, could result from

(A) a natural climatic variation
(B) an increase in solar reradiation
(C) a 20 percent decrease in atmospheric CO2 from current levels
(D) a decrease in trace gases in the atmosphere
(E) the replacement of fossil-fuel energy with solar energy

3 
 3. Which one of the following best describes the organization of the passage?

(A) A scientific problem is described, discrepancies among proposed solutions to it are evaluated, and a course of action is recommended.
(B) A scientific dispute is discussed and the case for one side is made, taking into account its political repercussions.
(C) A phenomenon is described, different views of its effects are presented, and a policy taking into account these differences is proposed.
(D) A solution to a scientific puzzle is advanced and its implications for action are discussed.
(E) A generally accepted scientific formula is explained in order to introduce a detailed examination of a case that violates the principle.

4 
 4. The author refers to the meteorological data gathered in North America over the past century in order to

(A) show how differing views on the extent of the rise in global temperature can be resolved
(B) argue that any warming detected over the past century has most likely been the result of a natural climatic fluctuation
(C) argue against the prevailing view that the amount of atmospheric CO2 has increased by about 20 percent over the past century
(D) suggest that there should be more numerous and accurate observation points outside of North America
(E) present evidence that casts doubt on the view that global temperature has increased over the past century

5 
 5. It can be inferred that the author of the passage would most likely agree with which one of the following statements about a response to global warming?

(A) The most effective measures that could be undertaken to reverse greenhouse warming are not necessarily the most costly.
(B) Costly measures necessary to combat greenhouse warming should be undertaken only when the rise in temperature begins to exceed human beings’ capacity to adapt to such an increase.
(C) Given the current state of knowledge about greenhouse warming, less costly measures should be implemented before expensive measures are tried.
(D) Scientists’ uncertainty about the effect of greenhouse warming on global temperature might be resolved more quickly if a “no regrets” policy were embraced.
(E) Any measure intended to reduce greenhouse warming should be implemented only if it also addresses other environmental problems.

6 
 6. Which one of the following is most analogous to the course of action recommended in the last paragraph?

(A) In response to uncertain predictions regarding the likelihood that an asteroid will collide with Earth, the government has decided to fund an inexpensive but scientifically valuable program to track asteroids and to determine whether more costly measures are warranted.
(B) Although scientists have not pinpointed how a newly discovered disease is spread, the government has implemented a preventive health program to combat the disease by preventing any likely means by which the disease might be communicated.
(C) In light of uncertain estimates about the remaining amount of fossil-fuel energy on the Earth, the government has set up a costly program to convert all industrial machinery to run on less expensive alternative fuels.
(D) Faced with many discrepant predictions about the depletion of the Earth’s ozone layer, the government has decided to adapt the preventive measures suggested by the scientific group that predicted the most rapid depletion.
(E) In response to scientific predictions that a disastrous earthquake is highly probable in a certain region, the government has added new requirements to building codes that require relatively inexpensive modifications of existing structures.

RC Butler 2023  -  Practice Two RC Passages Everyday.   
Passage # 92 Date: 05-Apr-2023
 This question is a part of RC Butler 2023 .  Click here for Details

Source:   LSAT Preptest February 1997   
 Difficulty Level:   600

pikaso · Answer

3. Which one of the following best describes the organization of the passage?

(A) A scientific problem is described, discrepancies among proposed solutions to it are evaluated, and a course of action is recommended.
(C) A phenomenon is described, different views of its effects are presented, and a policy taking into account these differences is proposed.

Option A and C looks close. But I cant find why A is wrong. Please help.

Sajjad1994 · Answer

In order to predict the answer to this kind of Global question, use your Roadmap to build a  “table of contents”  of sorts, paragraph by paragraph. The author describes a scientific phenomenon (Para 1), discusses its possible effects (Para 2), presents different views about its future effects (Para 3), and recommends a course of action based on the evidence (Para 4). Only  (C)  captures all these elements properly.

(A)  is incorrect the only  “solution”  the author presents is his or her own; no other proposed solutions are even mentioned, let alone evaluated.

priyanshii26 · Answer

Sajjad1994  can you please explain question 5?

Sajjad1994 · Answer

Explanation

5. It can be inferred that the author of the passage would most likely agree with which one of the following statements about a response to global warming?

Difficulty Level:   600-650

Explanation

The only place where the author discusses responses to global warming is in  Paragraph 4.  That paragraph will likely be the source of our inference here. While we may not be able to predict the right answer word for word, we know that the author is in favor of a more cautious approach to the global warming problem, at least until more information is available. Let’s use this to zero in on the right answer.

(A)  The author does recommend that we take less costly measures in the beginning, but that doesn’t mean that those measures will ultimately be the most effective in reversing greenhouse warming. Eliminate.

(B)  Again, the author says that costly measures should be taken, if warranted, once scientific knowledge grows. But there’s no indication of a threshold temperature past which the costly measures should be implemented. Eliminate.

(C)  sounds an awful lot like the author’s Main Idea, doesn’t it? This is what the author’s ultimately advocating, so we know that the author would agree with it. Select  (C)  and move on. For the record:

(D)  The author recommends adopting the “no regrets” policy until scientific uncertainty is resolved, but the passage never suggests that adopting such a policy will accelerate that resolution. Eliminate.

(E)  is too Extreme. The author says that because we aren’t sure that warming is happening, we should implement measures that make sense for other economic or environmental reasons. But that doesn’t mean that this is a necessary condition for implementing such measures. Eliminate.

Answer: C

Sahiba1 · Answer

Sajjad1994  can you please explain question 2?
why it couldn't be option B?

sachi-in · Answer

2. The passage suggests that a rise in global temperature over the next half century, if it occurs, could result from

(A) a natural climatic variation - could be one of the reasons
 (30) another puzzle remains: is the rise in global temperatures a natural fluctuation or a result of the increase in greenhouse gases? - could result from one of them or both

(B) an increase in solar reradiation - cools not warms
 (5) gases in the Earth’s atmosphere can contribute to what has been called greenhouse warming, because those compounds allow the Sun’s energy to reach the surface of the Earth, thereby warming it, but prevent much of that energy from being reradiated to outer space

(C) a 20 percent decrease in atmospheric CO2 from current levels - decrease may not be responsible, not mentioned in passage
(D) a decrease in trace gases in the atmosphere - decrease may not be responsible, not mentioned in passage 
(E) the replacement of fossil-fuel energy with solar energy - decreased to prevent the warming if greenshouse gas is the reason for warming

Increases in the amount of carbon dioxide (CO2) and other trace gases

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GMAT Reading Comprehension (RC) Questions

Increases in the amount of carbon dioxide (CO2) and other trace gases

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