Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

 It is currently 17 Jul 2019, 19:46

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Reducing atmospheric CO2 by a deliberate carbon dioxide

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 29 Jun 2017
Posts: 448
GPA: 4
WE: Engineering (Transportation)
Reducing atmospheric CO2 by a deliberate carbon dioxide  [#permalink]

### Show Tags

Updated on: 04 Mar 2018, 01:11
1
2
Question 1
00:00

based on 191 sessions

53% (03:21) correct 47% (03:16) wrong

### HideShow timer Statistics

Question 2
00:00

based on 187 sessions

44% (01:21) correct 56% (01:24) wrong

### HideShow timer Statistics

Question 3
00:00

based on 179 sessions

67% (00:56) correct 33% (01:14) wrong

### HideShow timer Statistics

Question 4
00:00

based on 171 sessions

55% (00:58) correct 45% (00:54) wrong

### HideShow timer Statistics

Reducing atmospheric CO2 by a deliberate carbon dioxide removal (CDR) strategy is one option being considered for combating global warming caused by the current high levels of atmospheric CO2. Before implementation can occur, it is important to have a reference goal for a planned reduction of the global CO2 concentration against which any specific strategy can be assessed. Scientists agree that a modest aim would be to seek to reduce the CO2 concentration by 50 ppm, which is the equivalent of removing 400 gigatons of CO2,or an average of 4 GtCO2/yr over 100 years. At this substantial level of reduction, it is still expected that dangerous levels of atmospheric CO2 would persist.

Even in the limiting case in which all emissions of CO2 cease, it is not straightforward to estimate how much CO2 must be removed from the atmosphere to lower its content by 4 GtCO2 annually. During any period of zero emissions but no CDR implementation, the atmospheric CO2 concentration will fall. Ocean currents continually bring deep ocean water to the surface that was last at the surface hundreds of years before, when the atmospheric CO2 concentration was at its preindustrial value. As equilibrium is established at the ocean surface between CO2 in the air and dissolved in the ocean, such ocean water scavenges CO2 from the atmosphere. So, with a time scale of hundreds of years, some atmospheric CO2 reduction is done naturally (at the expense of growing acidity in the ocean).

The same requirement for equilibrium at the ocean surface governs the reverse effect that would happen if the CO2 concentration of the atmosphere were lowered someday by deliberate removal of CO2. There would be an immediate compensating transfer of CO2 from the ocean to the atmosphere, as a result of which it would be necessary to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit. Forest responses add complications, as do deep ocean currents. Today, the combined effect of ocean and land CO2 “sinks” results, for a time-scale measured in decades, in roughly half of the CO2 remaining in the atmosphere that was emitted to the atmosphere by the burning of fossil fuel, but the future magnitudes of these sinks are uncertain.

Question1. Which of the following is listed as a natural phenomenon that would require a CDR strategy to remove CO2by an amount greater than its desired CO2 reduction target?

A) the presence of land CO2 “sinks”
B) the presence of ocean CO2 “sinks”
C) equilibrium at the ocean surface
D) deep ocean water moving to the surface
E) scavenging of CO2 by the ocean surface

Question 2. The author discusses ocean and land CO2 “sinks” in order to:

A) explain how much of the CO2 emitted by the burning of fossil fuels remains in the atmosphere

B) highlight how uncertain the future is regarding the magnitude of CO2 emissions from fossil fuels

C) highlight the challenges in determining natural effects on CO2 levels when implementing a CDR strategy

D) clarify why it would be necessary to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit

E) emphasize that there are many natural means by which CO2 is removed from the atmosphere.

Question 3. The author uses the content in the parentheses at end of the 2nd paragraph to:

A) provide additional information about how the natural process of atmospheric CO2 reduction occurs

B) emphasize the importance of a negative effect that would result from a natural process

C) highlight one result from the many natural processes related to CO2 removal

D) present a negative effect that is not directly related to the primary purpose of the paragraph

E) show the importance of natural removal of CO2 in the atmosphere

Question 4. All of the following are discussed in the passage EXCEPT:

(A) details on how CO2 will be removed from the atmosphere by a CDR strategy

(B) difficulties in measuring the effects of a CDR strategy on CO2 reduction

(C) increases in atmospheric CO2 levels resulting from natural processes

(D) decreases in atmospheric CO2 result resulting from natural processes

(E) the risk of high atmospheric levels of CO2 in the atmosphere

_________________
Give Kudos for correct answer and/or if you like the solution.

Originally posted by sahilvijay on 01 Mar 2018, 05:18.
Last edited by hazelnut on 04 Mar 2018, 01:11, edited 2 times in total.
Reformatted questions
Retired Moderator
Joined: 28 Mar 2017
Posts: 1212
Location: India
GMAT 1: 730 Q49 V41
GPA: 4
Re: Reducing atmospheric CO2 by a deliberate carbon dioxide  [#permalink]

### Show Tags

08 Mar 2018, 11:08
2
Got all correct. I hope this explanation helps someone

Reducing atmospheric CO2 by a deliberate carbon dioxide removal (CDR) strategy is one option being considered for combating global warming caused by the current high levels of atmospheric CO2. Before implementation can occur, it is important to have a reference goal for a planned reduction of the global CO2 concentration against which any specific strategy can be assessed. Scientists agree that a modest aim would be to seek to reduce the CO2 concentration by 50 ppm, which is the equivalent of removing 400 gigatons of CO2,or an average of 4 GtCO2/yr over 100 years. At this substantial level of reduction, it is still expected that dangerous levels of atmospheric CO2 would persist.

Even in the limiting case in which all emissions of CO2 cease, it is not straightforward to estimate how much CO2 must be removed from the atmosphere to lower its content by 4 GtCO2 annually. During any period of zero emissions but no CDR implementation, the atmospheric CO2 concentration will fall. Ocean currents continually bring deep ocean water to the surface that was last at the surface hundreds of years before, when the atmospheric CO2 concentration was at its preindustrial value. As equilibrium is established at the ocean surface between CO2 in the air and dissolved in the ocean, such ocean water scavenges CO2 from the atmosphere. So, with a time scale of hundreds of years, some atmospheric CO2 reduction is done naturally (at the expense of growing acidity in the ocean).

The same requirement for equilibrium at the ocean surface governs the reverse effect that would happen if the CO2 concentration of the atmosphere were lowered someday by deliberate removal of CO2. There would be an immediate compensating transfer of CO2 from the ocean to the atmosphere, as a result of which it would be necessary to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit. Forest responses add complications, as do deep ocean currents. Today, the combined effect of ocean and land CO2 “sinks” results, for a time-scale measured in decades, in roughly half of the CO2 remaining in the atmosphere that was emitted to the atmosphere by the burning of fossil fuel, but the future magnitudes of these sinks are uncertain.
Question1. Which of the following is listed as a natural phenomenon that would require a CDR strategy to remove CO2by an amount greater than its desired CO2 reduction target?

A) the presence of land CO2 “sinks” --Sinks reduce the Co2 levels
B) the presence of ocean CO2 “sinks” --Sinks reduce the CO2 levels
C) equilibrium at the ocean surface --Correct. If the CDR reduces CO2 then because of equilibrium oceans will release more CO2.
D) deep ocean water moving to the surface --It reduces CO2
E) scavenging of CO2 by the ocean surface --It reduces CO2

Question 2. The author discusses ocean and land CO2 “sinks” in order to:

A) explain how much of the CO2 emitted by the burning of fossil fuels remains in the atmosphere --Sinks reduce CO2

B) highlight how uncertain the future is regarding the magnitude of CO2 emissions from fossil fuels --Uncertainity id regarding the removal of CO2 not the emission from fossils

C) highlight the challenges in determining natural effects on CO2 levels when implementing a CDR strategy --COrrect. The 3 para talks about 2 challanges: equillibrium & forests+ocean sink

D) clarify why it would be necessary to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit --No. Only equillibrium causes this issue. SInks help in reducing CO2

E) emphasize that there are many natural means by which CO2 is removed from the atmosphere. --Certainly not

Question 3. The author uses the content in the parentheses at end of the 2nd paragraph to:

A) provide additional information about how the natural process of atmospheric CO2 reduction occurs --Wrong

B) emphasize the importance of a negative effect that would result from a natural process --Wrong

C) highlight one result from the many natural processes related to CO2 removal --Wrong

D) present a negative effect that is not directly related to the primary purpose of the paragraph --Correct. It is just an additional piece of information unrelated to the passage

E) show the importance of natural removal of CO2 in the atmosphere --Wrong

Question 4. All of the following are discussed in the passage EXCEPT:

(A) details on how CO2 will be removed from the atmosphere by a CDR strategy --Not discussed

(B) difficulties in measuring the effects of a CDR strategy on CO2 reduction --Talked in 3 para

(C) increases in atmospheric CO2 levels resulting from natural processes --Talked in 3 para

(D) decreases in atmospheric CO2 result resulting from natural processes --Talked in 2 para

(E) the risk of high atmospheric levels of CO2 in the atmosphere --Talked in 1 para

_________________
Director
Joined: 06 Jan 2015
Posts: 680
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Re: Reducing atmospheric CO2 by a deliberate carbon dioxide  [#permalink]

### Show Tags

10 Aug 2018, 21:04
1
Veritasprep Solution

Q 1

For this specific style question, you must find which one of the 5 natural phenomena would require such an increased removal. For (A) and (B), these are listed in the last paragraph as something that substantially reduces CO2 emitted by fossil fuels. If anything, these would allow a CDR strategy to remove CO2 by a lesser amount given a certain target, depending on whether these natural sinks have been accounted for. There is no evidence that these would require a greater amount to be removed. (C) is correct as it clearly states in the third paragraph in reference to ocean equilibrium: “There would be an immediate compensating transfer of CO2 from the ocean to the atmosphere, as a result of which it would be necessary to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit.” For (D), you learn in the second paragraph that deep ocean moving to the surface would have the opposite effect – like the “sinks” in (A) and (B), deep ocean moving to the surface would help remove CO2. Similarly for (E), the “scavenging of CO2 by the ocean” would involve removal of CO2 from the atmosphere and this would have the opposite effect than that required by the question stem. The correct answer is (C).

Q 2

As for any function problem, you need to find where the information referenced in the question stem is discussed and then examine the context. Importantly, for this particular problem, you must go outside of the paragraph in which you find the information, something you rarely need to do in function questions. Ocean and land CO2
“sinks” are discussed near the end of the third paragraph and they are being used as an example of natural processes that change CO2 levels but are uncertain in the future (it states “the future magnitude of these sinks is uncertain). The start of the second paragraph states: “Even in the limiting case in which all emissions of CO2 cease, it is not straightforward to estimate how much CO2 must be removed from the atmosphere to lower its content by 4 GtCO2 annually.” What follows in the 2nd paragraph are examples of natural effects that complicate this estimate. The third paragraph is simply a continuation of this, with more examples of how natural processes complicate the ability to estimate effects of a CDR strategy. As a result (C) is correct. For (A), this is certainly part of the discussion of land and ocean “sinks” – you learn that roughly 50% of CO2 emitted by the burning of fossil fuels are reduced by them – but this is not WHY the information is there. It is there to show why estimating the effects of natural processes on a CDR strategy is tricky. For (B), the “sinks” have nothing to do with uncertainty relating to the magnitude of emissions – the only uncertainty relates to how much CO2 they might pull out of the atmosphere in the future. For (D) you learn that the effects of ocean equilibrium might result in the need to remove more than one unit of CO2 from the atmosphere to reduce the atmospheric CO2 content by one unit. Land and ocean “sinks” would, if anything, result in the ability to pull out less than you need in a CDR strategy, as they help take CO2 from the atmosphere. For (E), the 2nd and 3rd paragraphs do not exist to demonstrate how many natural means exist for removing CO2 – they exist to show how hard it is to estimate the result of any CDR strategy because of natural processes. The correct answer is (C).

Q 3

As for any function problem, you need to find where the information referenced in the question stem is discussed and then examine the context.

The parentheses are used after the explanation that some CO2 reduction is done naturally when measured over a long period of time. With parentheses, they are used to either give additional information about what precedes them or to present an aside – something not directly relevant to the preceding discussion. Here it is definitely the latter – you learn some negative side effect of ocean equilibrium removing CO2 from the atmosphere. As a result (D) is correct. For (A), the information does not help you learn more about the process of reduction – that is explained before the sentence with parentheses. The portion in the parentheses simply presents a side effect of that process explained previously. For (B), this portion does not emphasize anything – it simply alerts the reader to a side effect of a process. Similarly for (C), the portion is not used to highlight a result (simply present it) and it is only the result of one, not many, processes. For (E), this information is not showing how natural reduction is good, it is simply showing one negative side effect of that reduction.

Q 4

For this style specific question, you must examine each answer choice carefully and look for it in the passage. Remember that wordplay/precision in wording are often in play for this type of question, so carefully analyze that in each choice. For (A), the entire passage was about the need for estimating the effects of any CDR strategy and the difficulties in making that estimate. Absolutely no details are given for exactly how these strategies remove the CO2 – as a result answer choice (A) is correct. (B) is clearly found in the passage in multiple places. The passage also addresses both decreases and increases in atmospheric CO2
levels from natural processes so (C) and (D) can be eliminated. (E) is tricky but you can find it at the end of the first paragraph. The sentence states: “At this substantial level of reduction, it is still expected that dangerous levels of atmospheric CO2 would persist.”Since the author states that the atmospheric levels of CO2 are high in the first sentence you can see that the risk of high atmospheric CO2levels is indeed discussed in the passage. Correct answer is (A)
_________________
आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution
Re: Reducing atmospheric CO2 by a deliberate carbon dioxide   [#permalink] 10 Aug 2018, 21:04
Display posts from previous: Sort by

# Reducing atmospheric CO2 by a deliberate carbon dioxide

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne