People associate global warming with temperature, but the phrase is mi

Question

People associate global warming with temperature, but the phrase is misleading-it fails to mention the relevance of water. Nearly every significant indicator of hydrological activity-rainfall, snowmelt, glacial melt-is changing at an accelerating pace (one can arbitrarily pick any point of the hydrological cycle and notice a disruption). One analysis pegged the increase in precipitation at 2 percent over the century. In water terms this sounds auspicious, promising increased supply, but the changing timing and composition of the precipitation more than neutralizes the advantage. For one thing, it is likely that more of the precipitation will fall in intense episodes, with flooding a reasonable prospect. In addition, while rainfall will increase, snowfall will decrease. Such an outcome means that in watersheds that depend on snowmelt, like the Indus, Ganges, Colorado river basins, less water will be stored as snow, and more of it will flow in the winter, when it plays no agricultural role; conversely, less of it will flow in the summer, when it is most needed. One computer model showed that on the Animas River an increase in temperature of 3.6 degrees Fahrenheit would cause runoff to rise by 85 percent from January to March, but drop by 40 percent from July to September. The rise in temperature increases the probability and intensity of spring floods and threatens dam safety, which is predicated on lower runoff projections. Dams in arid areas also may face increased sedimentation, since a 10 percent annual increase in precipitation can double the volume of sediment washed into rivers.

The consequences multiply. Soil moisture will intensify at the highest northern latitudes, where precipitation will grow far more than evaporation and plant transpiration but where agriculture is nonexistent. At the same time, precipitation will drop over northern mid-latitude continents in summer months, when ample soil moisture is an agricultural necessity. Meanwhile the sea level will continue to rise as temperatures warm, accelerating saline contamination of freshwater aquifers and river deltas. The temperature will cause increased evaporation, which in turn will lead to a greater incidence of drought.

Perhaps most disturbing of all, the hydrologic cycle is becoming increasingly unpredictable. This means that the last century`s hydrological cycle-the set of assumptions about water on which modern irrigation is based-has become unreliable. Build a dam too large, and it may not generate its designed power; build it too small, and it may collapse or flood. Release too little dam runoff in the spring and risk flood, as the snowmelt cascades downstream with unexpected volume; release too much and the water will not be available for farmers when they need it. At a time when water scarcity calls out for intensified planning, planning itself may be stymied.   1 
 1/ According to the last paragraph, planning itself may be thwarted for which of the following reasons?

A Many regions lie in flooding areas and will not be able to be evacuated in time.

B The hydrological cycle for this century has become predictable, but experts are still uncertain about rainfall in certain parts of the world.

C There is too little information from last century to aid in the construction of dams.

D Information used to plan the size of certain environmental projects, such as dams, has become dated.

E Scientists are only just coming to appreciate the complexity of global warming.

2 
 2/ According to the passage, the likelihood that “dams in arid areas also may face increased sedimentation” will most likely result from

A an increase in precipitation

B a decrease in the annual snowmelt

C the rise in the average annual temperature of major rivers

D a shift in the seasonality of precipitation

E a rise in sea level

3 
 3/ The passage is primarily concerned with

A arguing how the world’s hydrological cycle is irrevocably changing
B highlighting the inadequacy of relying on last century’s hydrological cycle
C discussing the consequences of decreased water supply in dams
D warning against the unrestrained exploitation of natural resources
E describing how the Earth’s water will be affected by global warming

4 
 4/ Based on information in the second paragraph, which of the following can best be supported?

A Precipitation across different latitudes can differ significantly.
B An increase in soil moisture can have devastating effects on agriculture.
C Increased temperatures at sea level can affect the highest altitudes.
 D Saline contamination mostly results from an increase in sea levels.
E Hydrological activity at one elevation has little to no effect on hydrological activity at another elevation.

akshata19 · Answer

Took 8 min 30 secs 
This was a simpler passage 
Is the time taken too much?

Posted from my mobile device

arvind910619 · Answer

Hi  akshata19 ,
Can you please explain the last question as to why B is wrong ?

Thanks ,
Arvind

GMAT215 · Answer

need to read 2nd para

"The consequences multiply.  Soil moisture  will intensify at the highest northern latitudes,  where precipitation  will grow far more than evaporation and plant transpiration but where agriculture is nonexistent. At the same time,  precipitation will drop  over northern mid-latitude continents in summer months, when ample soil moisture is an agricultural necessity.

above part talks about precipitation at different latitude & its effect on soil moisture and then effect on agriculture.

Confusion is between two below i suppose:

A Precipitation across different latitudes can differ significantly. - Directly mentioned

B An increase in soil moisture can have devastating effects on agriculture. - may not have devastating effect on agriculture in the higher northern latitude where it is currently does not exist.

i tried to explain in my words, hope it helps.

aragonn · Answer

Official Explanation for Q1 
The last paragraph says, “the set of assumptions…has become unreliable.” Therefore, building dams is difficult because engineers may build a dam that is too big or one that is too small. The set of assumptions are based on the hydrological cycle from last century, assumptions that have become dated. This leads us to (D).

(A)does not relate to the question.

(B)Is incorrect because the passage says that the hydrological cycle from last century is not relevant.

(C)Is too vague. What is meant by “too little information.” There is plenty of information from last century; however, it has become dated.

(D)The answer.

(E)Is too generic and it doesn’t answer the question about planning being thwarted.

aragonn · Answer

Official Explanation for Q3:

Answer: (E)

(E) succinctly expresses the main idea of the passage, which can be found at the very beginning, “People associate global warming with temperature, but the phrase is misleading—it fails to mention the relevance of water.”

(A) is very tempting, but note that the passage does not say ‘irrevocably.’ Sure, we may be guided by our own thoughts on global warming, but there is nothing in the passage to say that the change is irrevocable.

(B) and (C) are too specific. (D) is too general and does not match with the tone of the passage.

aragonn · Answer

Official Explanation for Q4

Answer: (A)

(A) is supported by, "Soil moisture will intensify...latitudes", and "precipitation will drop...mid-latitude continents.

(B) is wrong because the question is focused on the second paragraph.

(C) and (E) both refer to altitude; the passage is referring to latitude.

(D) is a trap answer. It takes information in the passage and stretches it too far. Specifically, we know that rising sea levels CAN cause saline contamination. However, we don't know that "saline contamination mostly results" from a rise in sea level. There could be other factors accounting for saline contamination; however, the passage doesn't mention these at all.

jaisonsunny77 · Answer

(1) According to the last paragraph, planning itself may be thwarted for which of the following reasons?

In the second sentence of the last paragraph, we have "....the last century`s hydrological cycle....has become unreliable". (D) reflects this though perfectly

(D) Information used to plan the size of certain environmental projects, such as dams, has become dated.
Hence,   (D) is the right answer choice here.

(2) According to the passage, the likelihood that “dams in arid areas also may face increased sedimentation” will most likely result from

In the last line of the first paragraph, we have "Dams in arid areas also may face increased sedimentation, since a 10 percent annual increase in precipitation can double the volume of sediment washed into rivers." (A) reflects this perfectly.

(A) an increase in precipitation 
Hence,   (A) is the right answer choice.

(3) The passage is primarily concerned with

In the first paragraph, the author asserts that ''not enough attention is being given to the relevance of water in global warming''. The second and third paragraphs are constructed to emphasize on the wide environmental consequences of rapidly varying water levels accelerated by global warming.

(E) describes this flow of information perfectly. 
(E) describing how the Earth’s water will be affected by global warming

Hence,   (E) is the right answer choice .

(4) Based on information in the second paragraph, which of the following can best be supported?

(A) Precipitation across different latitudes can differ significantly. - we can infer (A) from the first two sentences of the second paragraph. Hence,  (A) is the right answer choice. 
  
(B) An increase in soil moisture can have devastating effects on agriculture.  -  the second paragraph does not form a link between soil moisture and ''devastating effects'' on agriculture.   
(C) Increased temperatures at sea level can affect the highest altitudes.  -  the second paragraph links increased temperatures with saline contamination  
(D) Saline contamination mostly results from an increase in sea levels.  -  the second paragraph does not assert 'increased in sea levels' as the primary cause of saline contamination.   
(E) Hydrological activity at one elevation has little to no effect on hydrological activity at another elevation . -  cannot be inferred from the second paragraph.

aditiphadnis · Answer

9.51 mins 
All ans correct. 
Is that too long? I took time to understand the passage correctly.

Posted from my mobile device

VerbalBot · Answer

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People associate global warming with temperature, but the phrase is mi

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People associate global warming with temperature, but the phrase is mi

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