Increased atmospheric concentrations of carbon dioxide (CO2 )

Question

Increased atmospheric concentrations of carbon dioxide (CO2) in the atmosphere can have a fertilizing effect on certain crops, provided that it is possible for farmers to provide adequate water and fertilizer for the plants to grow more quickly. For this reason, many non-scientists have long held that increases in global atmospheric carbon dioxide will also lead to increased agricultural production, offsetting any shortages due to shifting water availability and increased temperature. This in turn, these individuals argue, will lead to decreased global malnutrition and undernutrition as the increased supply of food drives down its cost.

However, research on the nutritional content of crops grown at Free Air CO2 Enrichment - or FACE - sites suggests that while crops may grow more quickly in elevated concentrations of carbon dioxide, increased growth comes at a price. Crops grown in elevated levels of carbon dioxide have lower levels of protein and of micronutrients such as zinc. Since the world’s population gets the majority of its protein and other micronutrients from plant-based sources, such a shift could have dire consequences. Scientists estimate that by 2050 an additional 175 million people could become zinc deficient, and an additional 120 million could become protein deficient as the nutritional content of staple crops falls between 5 and 17 percent.  
 1 
 C 
 1. The author uses the word “non-scientists” in paragraph 1 to:

a) criticize those who make predictions without sufficient knowledge of a topic.
b) highlight the expertise of the researchers at Free Air CO2 Enrichment.
c) call into question the inferences discussed in the first paragraph.
d) demonstrate that the farmers mentioned in the previous sentence did not make the predictions that follow.
e) imply that their predictions were made without any evidence.

2 
 B 
 2. The passage suggests that the nonscientists mentioned in paragraph 1 fail to consider whether or not the growth rate increase mentioned in paragraph 1

a) will also lead to an increase in the amount of edible material that the plants produce.
b) is associated with any phenomena that would affect its ability to decrease global malnutrition.
c) will require better distribution systems in order to mitigate zinc deficiency.
d) can offset the deleterious effects CO2 related warming will have on water availability.
e) will occur in actual crops to the same extent as it has occurred at FACE sites.

3 
 D 
 3. Which of the following can be inferred from the passage?

a) If carbon dioxide levels do not increase, there will not be an increase in the number of people who are zinc deficient.
b) Increased carbon dioxide levels will not, despite what many non-scientists predict, cause crops to grow more quickly.
c) It is possible for farmers to provide adequate water and fertilizer for crops to grow more quickly in an increased-carbon environment.
d) There are currently some people who are considered to have a zinc deficiency.
e) Most micronutrients are only available via plant-based sources.

4 
 A 
 4. It can be inferred from the passage that increased atmospheric carbon dioxide

a) can decrease the nutritional content of plants.
b) increases the rate at which most plants grow.
c) will lead to increased agricultural production.
d) is the biggest threat to global nutrition that the world faces today.
e) will cause millions of people to become zinc deficient by 2050.

Gladiator59 · Accepted Answer

Since it is an inference type question we need to be 100% sure that what we infer will occur given the passage.

It can be inferred from the passage that increased atmospheric carbon dioxide

a) can decrease the nutritional content of plants.  Clearly mentioned in second para 
b) increases the rate at which most plants grow.  Most is a red flag making statement extreme as the passage does not mention "most" plants 
c) will lead to increased agricultural production.  "Will lead" is too strong and we cannot predict the future. 
d) is the biggest threat to global nutrition that the world faces today.  Non-sensical there could be other bigger threats 
e) will cause millions of people to become zinc deficient by 2050.  Again "will cause" is too strong

Hope it is clear.

Best,
Gladi

bhavik1995 · Answer

Q3 - It is written -'Additional million people will suffer from zinc deficiency' so it can be inferred that some people already suffer from zinc deficiency. Hence option D.
Which option did you chose?

Q2 - Non scientists say increase of CO2 is good. But research says that increase of CO2 is not good because it decreases nutritional content of crops. hence global malnutrition.
Earlier non scientists didn't consider this association/relationship of increase in CO2 and malnutrition.
Therefore option B.

Please give  Kudos  if I were helpful.
Thanks!

raghavrama21 · Answer

Please explain question 2 and 3.

globaldesi · Answer

OE Question 2

This specific question requires that you first understand what nonscientists are arguing and then that you look beyond that information to understand the flaw in that argument. Since the question asks about the nonscientists mentioned in paragraph 1, it's helpful to first think about what those nonscientists believe. Paragraph 1 states that they believe that because increased atmospheric CO2
 can have a fertilizing effect on crops, that rising levels of CO2
 will increase production in crops preventing food shortages and decreasing malnutrition.

To understand what the author thinks those people fail to consider, you then need to look at the next paragraph. (The word "however" at the beginning of that paragraph is a great indication of a shift occurring.) The next two sentences state that faster growth comes at the cost of nutritional content. This best matches answer choice (B): these nonscientists don't take into account that there might be phenomena that prevent this increased growth from actually affecting malnutrition.

Among the other answers, (A) can be eliminated because the ratio of edible to nonedible material isn't discussed, and (C) can be eliminated because distribution isn't discussed. (D) can also be eliminated because it is too specific: the author doesn't directly make any claims about water availability's effects, and (E) can be eliminated because there is no claim made that these two growth rates would differ.

OE Question 3

For this question, you should go straight to the answer choices, looking for the proposed inference that is guaranteed to be true based on the information provided in the text.

Choice (A) can be eliminated because the author doesn't give enough support to justify this inference. While it is possible that the number of people with a zinc deficiency wouldn't increase, it's also just as possible that a country could have a population boom, leading to famine and therefore more people with zinc deficiency. Both of these scenarios are allowed by the text.

Choice (B) can be eliminated as well since it runs counter to the information provided. While it's certainly possible, there is no evidence that crops will do anything other than what is described in the text.

Choice (C) is close, but isn't guaranteed. The passage says that increased yields will occur "provided" that farmers can get enough water and nutrients to plants, but doesn't state one way or the other whether this is actually possible.

Choice (D) is correct. The author states that "an additional" 175 million people could become zinc deficient, making it possible to infer that at least a few people worldwide are currently zinc deficient.

Choice (E) can be eliminated because you are told that the majority of micronutrients come from plant sources, but the word "majority" doesn't rule out the existence of alternative sources.

ShankSouljaBoi · Answer

What is wrong with B in question 4 ? Please guide.

Regards

globaldesi · Answer

OE Question #4

As with any inference question, your goal should be to consider each answer and whether the inference provided is guaranteed by the passage. For these questions it can be difficult to anticipate what inference the question will make, so your strategy of attack should be to just dive in and consider each answer choice independently.

Choice (A) is a valid inference. If increased carbon dioxide can cause zinc deficiency in plants, then since zinc is a type of nutrient, increased carbon dioxide can also cause general nutrient deficiency. Note also the appearance of the word "can" - a much easier level of proof than "will" or "always."

Choice (B) is not a valid inference because it's stated that the fertilizing effect occurs "on certain crops" but doesn't state what proportion of plants is affected. The presence of the word "most" here sets the burden of proof at a high level - it's not enough for "some" plants to be affected, you need to be able to prove that it's more than 50%, and evidence just doesn't exist for that level of proof.

Choice (C) can be eliminated because the passage states that increased agricultural production will only occur if farmers can provide adequate nutrients and water, something that isn't guaranteed by this question.

Choice (D) can be eliminated through lack of evidence. While nutrient deficiencies are an issue, there is indication as to the relative importance of this issue.

Choice (E) can be eliminated for reasons similar to choice (E). While it is possible that the outcome described will occur, any number of events could prevent (E) from occurring (better technology, a meteor strike, etc).

thangvietnam · Answer

for most passages, understanding main idea and structure of the passages are hard and answering the questions which is based on understanding the main ideas is easy. for some passage such as this one, understanding the main idea is easy but answering the questions is hard. the focus of this passage is the infering. though the passage is easy to understand, the questions are hard and require a high lever of infering. realizing which information is correct and which information is probably correct is key to success on answering the hard questions from the easy passage.

Wonderwoman31 · Answer

GMATNinja ,  VeritasKarishma ,

Could you please suggest the strategy to answer question1 of the passage?

jawele · Answer

GMATNinja

I'd like to learn the same. Could anybody please shed some light on how to to tackle this question? I picked E but realised that "without any" is too strong/unjustified

Thank you

gmatconqueror2018 · Answer

3/4 in about 7:45. Got the last question wrong. Why can't we infer that increased CO2 leads to an increase in the rate in which plants grow? A is inferrable from the 2nd paragraph but why about B? To quote: "research on the nutritional content of crops grown at Free Air CO2
Enrichment - or FACE - sites suggests that while crops may grow more quickly in elevated concentrations of carbon dioxide"

Any thoughts would be welcomed. I'd be happy to share my logic on the first three questions.

Tanmay127101994 · Answer

Can anyone explain question no 1 .

ajarpit60 · Answer

I marked E for Q1. Please explain why the answer is C.

Sajjad1994 · Answer

Official Explanation

1. The author uses the word “non-scientists” in paragraph 1 to:

Difficulty Level:   Hard

Explanation

This  function question  requires that you consider the word  "nonscientists"  in the context of the paragraph provided in order to understand why this word is used. In context, you are told that based on one piece of information, nonscientists come to one conclusion but that the truth is more complicated, since there are more variables in play. This best fits  choice (C) : the word nonscientist works to call the inference that these individuals make into question. Among the other answers,  (A)  can be eliminated because the word  "criticize"  is too strong for the analytical tone of the passage.

(B)  can be eliminated because no contrast is made between the individuals in each paragraph.

(D)  can be eliminated because there is no indication that the nonscientists and farmers aren't the same people.

(E)  can be eliminated because they do have some evidence - just not all the evidence available.

Answer: C

nikitasharma8 · Answer

please explain why e is not answer?

miag · Answer

can someone explain Q1-3?  Sajjad1994   GMATNinja

Increased atmospheric concentrations of carbon dioxide (CO2 )

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GMAT Reading Comprehension (RC) Questions

Increased atmospheric concentrations of carbon dioxide (CO2 )

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615 to 715 in 15 Days (Ria's Strategies)

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