Researchers have updated their forecasts of the impact of melting ice

Question

Researchers have updated their forecasts of the impact of melting ice sheets on the  planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will raise sea levels by nearly 10 inches, which is an influx of water critically disrupting  the ocean currents vital to our weather.

A) planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will raise sea levels by nearly 10 inches, which is an influx of water critically disrupting

B) planet and have predicted that by 2100, the shrinking ice sheets of Antarctic and Greenland will raise by 10 inches the sea levels, critically disrupting influx of water and

C) planet and predict that the shrinking Antarctic and Greenland ice sheets by 2100 will raise sea levels by nearly 10 inches and that the influx of water will critically disrupt

D) planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches, an influx of water that will critically disrupt

E) planet, predicting that by 2100, the sea levels will raise by nearly 10 inches by shrinking Antarctic and Greenland ice sheets; this influx of water will critically disrupt

ahabib · Answer

A.
planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will raise sea levels by nearly 10 inches,  which  is an influx of water critically disrupting 
Which is incorrectly modifying "Inches"

B.
planet and have predicted that by 2100, the shrinking ice sheets of Antarctic and Greenland  will raise by 10 inches the sea levels , critically disrupting influx of water and 
Will be raised by 10 inches
or
Will raise sea levels by 10 inches

This changes meaning & doesn't actually make sense

C.
planet and  predict  that the shrinking Antarctic and Greenland ice sheets by 2100 will raise sea levels by nearly 10 inches and that the influx of water will critically disrupt 
"Predict" is

1) Changing the meaning
2) Not parallel (verb tense is wrong)
3) Wrong construction

We should be expecting a modifying clause, not a parallel clause.

D.
planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches, an influx of water that will critically disrupt 
 Good

E.
planet, predicting that by 2100,  the sea levels will raise by nearly 10 inches by shrinking Antarctic and Greenland ice sheets ; this influx of water will critically disrupt

Sea levels aren't doing the action.. It's the melting ice sheets that are raising the sea levels..

There are also a bunch of idiom issues in there that render this construction meaningless.

AcetheGMAT2019 · Answer

generis  - the god of SC - pls help

amarsinha · Answer

A - which incorrectly refers to 10 inches. 
B - whether the ice sheets will rise or they will raise sea levels is not clear. Changes the meaning....rise of sea levels is not disrupting influx of water...
C - have updated and predict is not parallel. Should be predicted. 
D - seems to be correct
E - the sea levels will rise...

IMO D seems to be the best choice.

generis · Answer

MORE CONDENSED ANSWER AcetheGMAT2019 , I am definitely a mere mortal.

This question is hard. Subtle errors. Weird verbs. The second post, HERE contains: (1) slightly longer POE (2) logical sequence, (3) fuller discussion of future perfect, and (4) links to a couple of sites. • 4-1 SPLIT: By the time X, Y See the diagram at the bottom of the page. BY THE TIME X, Y is a phrase telling us that we have a time shift IN the sentence. The time shift must be conveyed by verb tense shifts. We are in the future. The X event happens latest-in-time in the future. The X element takes simple future . The Y events happen and are finished before the X event happens . The Y events take future perfect = WILL + HAVE + PAST PARTICIPLE (verbED) X event = something will critically disrupt the ocean currents Y event = finished before X = ice sheets will have raised sea levels By the time X, Y can also be set in the past . See the footnote* Process of elimination THE PROMPT THE OPTIONS • will raise should be will have raised • WHICH is a noun modifier that cannot modify an entire clause (the shrinking . . .) In this sentence, which could modify 10 inches or sea levels. Neither 10 inches nor sea levels are "an influx of water." • incorrect: IS. This context is prediction, not general or absolute truths. In this context, the use of IS does not fit with the idea of predicting what WILL happen. • critically disrupting is misplaced. It incorrectly modifies the influx of water. Participles without commas modify the immediately preceding noun. ELIMINATE A • will raise should be will have raised • will raise by 10 inches the sea levels is not nearly as good as will raise sea levels by nearly 10 inches The object of the verb is the sea levels, which should be placed right after the verb • this whole last part of the sentence is a mess: critically disrupting influx of water and the ocean currents vital to our weather.

-- the word AND is a parallelism marker. Not parallel: critically disrupting influx of water (not a noun! no article) and the ocean currents Eliminate B • will raise should be will have raised • misplaced modifier: BY 2100. What, exactly, are ice sheets by 2100 ? Nonsense. --prepositional phrases that refer to a specific time or point in time almost always are placed at the beginning of the clause or follow the verb that they modify Eliminate C • predicting is a participial modifier that correctly modifies the preceding clause • by 2100 = By the time X, Y. The Y events come before the X event and take future perfect, as is the case in this sentence: will have raised The X event is last in time and takes simple perfect, as is the case here: will critically disrupt • "an influx of water" is a way to restate the noun equivalent of the preceding clause. The phrase is called a summative modifier. An influx of water summarizes and encapsulates the idea expressed in the previous clause. Now the sentence is set up correctly to take the THAT clause in which the final outcome (the X event) can be expressed properly KEEP • Sea levels WILL HAVE RISEN, not "raise" . The levels will not lift something up. The whole combination is absurd. • Wrong active subject (sea levels) and wrong verb (levels RISE, future perfect = levels WILL HAVE RISEN) - not "raise" in any form. Read hard constructions for meaning and forget about the rules for a minute. . . . the sea levels will raise by 10 inches by shrinking Antarctic and Greenland ice sheets Move one of the poorly placed modifiers: The sea levels will raise by shrinking Antarctic and Greenland ice sheets

Sea levels do not shrink ice sheets. Sea levels do not raise ice sheets. Sea levels do not raise themselves by 10 inches. -- Sea levels ARE raised by 10 inches , OR -- Sea levels RISE by 10 inches -- by 10 inches is misplaced (compare to D) • Subject + Verb + "by ___ING" = the BY phrase tells us how the verb worked. The sea levels can raise . . . ice sheets by shrinking them? Since when could sea levels raise ice sheets at all, never mind raise ice sheets BY shrinking ice sheets? No. Eliminate E The answer is D I hope that analysis helps.

** By the time X, Y in the past? On the GMAT, this code word phrase is more often set in the past than in the future. Either way, "by then , Y" means that X happens later in time, and the Y events happen before X WHAT TO DO when By the time X, Y is set in the PAST. Please see my post here. It explains how to handle "By the time X, Y" when the events are in the past. future-perfect-examples-writing.png

generis · Answer

This question is hard. We must contend with shifting verbs, subtle errors, and difficult verb tenses. The phrase "by then" indicates a time shift. When you see any phrasing that resembles By the time X, Y then you know that time will shift within the sentence and verbs must also shift. The verb shifts reflect the time shifts. Scroll down below POE for: (1) sequence and (2) fuller discussion of By the time X, Y and future perfect • PROCESS OF ELIMINATION THE PROMPT THE OPTIONS • will raise is incorrect and should be will have raised (sea levels). Will raise is simple future. That tense does not work with the verb shift implied by the phrase By the time X, Y (see below) -- By 2100 is a signal that verb tenses must shift in order to convey time shifts. -- The construction is By the time X, Y (1) the X event comes later in time. We use simple future for that event. (X = will critically disrupt, correct) (2) the Y events come before X. We use (gah, jargon) future perfect for the Y events. (Y = will have raised ) -- The Y events must be in future perfect because they are finished before the X event. The Y events are done. We convey that fact by using WILL + HAVE + past participle (explained more below) • WHICH cannot modify an entire clause ( . . . the shrinking . . . ). Which improperly refers to the idea expressed by the whole clause, but no noun antecedent exists. • WHICH is a noun modifier. In this sentence, which could modify 10 inches or sea levels. Neither is "an influx of water." • this verb is incorrect: IS. This context is prediction, not general or absolute truths. In this context, the use of IS does not fit with the idea of predicting what WILL happen. • does critically disrupting refer to the influx of water or to the ocean currents ? On the GMAT, an ___ING modifier without a comma refers to the immediately preceding noun. Nonsense: the influx of water is not critically disrupted • will raise should be will have raised • will raise by 10 inches the sea levels is not nearly as good as will raise sea levels by nearly 10 inches -- whenever possible and unless emphasis is needed, if the verb is one word (not phrasal, e.g.) we do not separate verbs from their direct objects. -- the verb raise means to elevate and needs a direct object. Elevate WHAT? Raise WHAT? What the heck is "by 10 inches"? a noun? NO. The sea levels should be placed right after the verb • this whole last part of the sentence is a hot mess: critically disrupting influx of water and the ocean currents vital to our weather.

-- the word AND is a parallelism marker. On the right side of AND is a noun (the ocean currents). On the left side of AND is an ___ING phrase If influx of water is the noun, it needs a THE before it. If influx of water is not the noun, then "critically disrupting influx of water" should be noun. That noun both makes no sense and deprives "the ocean currents" of its modifier (critically disrupting) Eliminate B • will raise should be will have raised • misplaced modifier: BY 2100 is misplaced and bizarre • what, exactly, are ice sheets by 2100 ? Nonsense. -- Although subjects and verbs can be separated by modifiers, and although prepositional modifiers such as by 2100 can be placed more freely than adjectives, these modifiers still must be clear about what they modify. -- prepositional phrases that create a specific point in time almost always come at the beginning of the clause or sentence or follow the verb they modify Correct : I will be at home by noon . Wrong : I by noon will be at home. Correct: By noon, I will be at home. Eliminate C (D) Researchers have updated their forecasts of the impact of melting ice sheets on the planet, predicting that by 2100 , the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches, an influx of water that will critically disrupt the ocean currents vital to our weather. • predicting is a participial modifier that correctly modifies the preceding clause • by 2100 = By the time X, Y. The Y events come before the X event and take future perfect, as is the case in this sentence: will have raised The X event is last in time and takes simple perfect, as is the case here: will critically disrupt • "an influx of water" is a way to restate the noun equivalent of the preceding clause. The phrase is called a summative modifier. An influx of water summarizes and encapsulates the idea expressed in the previous clause. Now the sentence is set up correctly to take the THAT clause in which the final outcome (the X event) can be expressed properly KEEP • Wrong active subject (sea levels) and wrong verb (will raise) • RAISE/RISE confusion . Grammatically, this part should say that sea levels WILL HAVE RISEN. To raise is to lift something up. The levels will not lift something up. To rise is to go from a lower to a higher position. A level can rise. A sea level cannot raise itself. The whole combination is absurd. • Read hard constructions for meaning and forget about the rules for a minute. . . . the sea levels will raise by 10 inches by shrinking Antarctic and Greenland ice sheets . . . 1) sea levels do not shrink ice sheets 2) sea levels do not raise ice sheets 3) sea levels do not raise themselves by 10 inches. -- Sea levels ARE raised by 10 inches, OR -- Sea levels RISE by 10 inches 4) raise needs a direct object. Well, that direct object cannot be by 10 inches. That thing is not a noun! Subject - Verb - Object. Here we have Subject - Verb - preposition of manner - preposition of cause - OBJECT

I don't know how to explain how bad this construction is. Please. Everyone. Start reading. Read Harvard Magazine . You can get it for free HERE . It contains short and long passages (RC, anyone?). The subjects are fascinating. The prose is good and well-edited. You will not fall asleep. • Subject + Verb + "by ___ING" = the BY phrase tells us how the verb worked. So . . . the sea levels can raise . . . ice sheets by shrinking them? Since when could sea levels shrink ice sheets? Eliminate E. The answer is D *************** • LOGICAL SEQUENCE Let's try to get just the logical sequence. We will worry about verb tenses right after that sequence. Moment 0 is NOW: researchers have recently changed their predictions about the impact that melting ice sheets will have on the planet What do they think will happen? Do not worry about verb tenses 1) ice caps will keep melting 2) melting ice will release water into the oceans 3) that water will elevate / increase / raise sea levels 4) when the year 2100 hits ("by 2100"), the levels will be almost 10 inches higher than they are now 5) the final effect will be that the extra water (the influx of water) will critically disrupt (will seriously damage) ocean currents (and thus also will disrupt weather, because ocean currents are extremely important factors in the kind of weather the planet has and the way that the weather behaves) • BY THE TIME X, Y = By 2100, _____* By the time X, Y signals a time shift that must be reflected by verb shifts. By the time X, Y? X = simple future Y = future perfect By 2100 immediately tells us that we have a time shift. By 2100 is the latest-in-time event. It marks off a precise moment in the future. By 2100 means at this point in time. Before that time, another event happens and gets finished. By 2100 is an example of this construction: By the time X, Y The X event comes last in time. Final event X takes simple future . Look at our logical sequence. Final event X = will critically disrupt The Y events come before X in time. Y events take something called future perfect: will + have + past participle Y = #3 in our sequence will raise or will have raised ?? Correct: Will have raised. Why? Because By the time X, Y is a phrase in English that indicates verb tense shifts. In particular, the Y events happen and are finished before the X event happens. The verbs must express those two different times signaled by By the time X, Y. The tense will have raised is called future perfect . -- the "perfect" part derives from "perfectED," which means . . . finished. Done. Over with. -- the past participle raised is a completed action. -- future perfect tense will have raised tells us that the event Y ends at some point in the future—and then the X event will happen. See the diagram at the bottom. These sites give a quick overview of future perfect: and HERE, #1 and HERE, #2 ******************* ** FOOTNOTE: By the time X, Y in the past? On the GMAT, this code word phrase is more often set in the past than in the future. Either way, "by then , Y" means that X happens later in time, and the Y events happen earlier in time. WHAT TO DO when By the time X, Y is set in the PAST. Please see my post here. It explains how to handle these "code words" when the events are in the past. future-perfect-examples-writing.png

globaldesi · Answer

the statement says "will have .." but the entire statement is in reported speech
Is usage of will have correct and should it not be "would be .."
Can you help?

generis · Answer

globaldesi  , I must be missing something. 
Please elaborate a little bit about "reported speech"?

The time is the present. (Researchers have changed their forecasts,   predicting . . .)

EDIT:  globaldesi  ,
You may want to take a look at this official question,  HERE

Or this official question,  HERE .

vanam52923 · Answer

@e-GMAT
 generis

Need clarification
Doubt 1:
The scientists have updated the report and result of report is predicting---no sense
The scientists have updated report , how/why have they updated-- precitng so makes sense
Am i right on this?

Doubt 2:

I get confused by such sentence structures
plz clarify this:

Option D is :

Researchers have updated their forecasts of the impact of melting ice sheets on the planet, predicting that by 2100, the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches, an influx of water that will critically disrupt the ocean currents vital to our weather.

here an influx of water---our weather is noun +noun modifier and that modifies whole action of shrinking and rasing of levels so its fine

how does comma between 2100 and the shrinking Antarctic makes sense??

the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches is an independent clause so cannot be connected by ,
though logically its is claer that it is part of verbing modifier predicting

but how does this serntence structure makes sense ?plz enlighten me on such structures

researchers have -----planet, predicting ...by 2100,the shrinking ------10 inches
if senetcne is only till 10 inches how does it make sense?
if it had been 
reaserchers have..planet ,predicting that the shrinking Antarctic and Greenland ice sheets will have raised sea levels by nearly 10 inches by 2100
this makes sense (note no comma btwn that and the shrinking now)

Plz explain

generis · Answer

@e-GMAT
 generis

Hi  vanam52923  ,  predicting  is logically related to the main clause.
The sentence contains an implicit "now, " this way . . . .
 Researchers have updated their forecasts of the impact of melting ice sheets on the planet, predicting     that by 2100,..

The researchers have revised their forecasts. Because they changed their forecasts, now they are predicting something new.

You are correct that a participial modifier often presents the result of the preceding clause. 
  is not restricted to that role.

Participial modifiers (comma + verbing) can modify the preceding clause, the subject of that clause, or the immediately preceding noun. 
The latter is rare on the GMAT but not in formal writing otherwise. One official example is  here

I suppose if we wanted to get really literal we could say that  predicting XYZ  tells us  how  the researchers have changed their forecasts. 
Alternatively, we can say that the result of an updated forecast is predicting something different from before.
 
I am not sure that I understand what you are saying. I think we agree.

"An influx of water . . . " is indeed a noun + a noun modifier (a that-clause).
The mere fact that  an influx of water  is a noun + noun phrase does not make it eligible to modify the entire sentence.

My confusion may be a jargon problem. The issue is placement and function. Noun + noun phrase as an intro, for example, must modify the  subject  of the subsequent clause, not the whole clause. We are looking at a special kind of appositive, which is allowed because it captures the whole idea of the preceding clause.

That special kind of appositive,  an influx of water...,  is a  summative modifier,  which  by definition  modifies the clause that precedes the modifier.

A summative modifier uses new words that encapsulate the whole idea of the main clause.
"Summative" derives from "summarize."

If you read these  short  posts, this type of modifier may be a little more clear.

Short articles on summative modifiers: (1)  HERE  (Thought Co. The examples are great), and (2) one by Chris Lele at Magoosh:  HERE .

Again, I am not sure that I understand what you mean.

Are you arguing that a comma after "2100" makes the entire sentence incomprehensible? I can't quite tell from truncated sentences. I must be missing something.

Dates that come in the middle of the sentence  usually take  a comma after the year  unless the date phrase consists of only month and year.
Correct: The film was originally released in August 2010 to sold out theaters.
Correct: The film was originally released on August 1, 2010, to sold out theaters.

Here are official sentences in which a prepositional phrase that includes a year is in the middle of the sentence and is rightly set off by commas.
 HERE 
 HERE

I can see that you are putting in a lot of effort to master this material.

I hope that these answers help.

vanam52923 · Answer

Thanks a lot man for such an elaborate reply.Much appreciated.i will go thorugh all the links which u have mentioned.Much appreciated:)

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Researchers have updated their forecasts of the impact of melting ice

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