Q25 - Oceanographer: To substantially reduce the amount

[mshinners]

Question Type:
Necessary Assumption

Stimulus Breakdown:
CO2 pumped into the deep ocean will dissolve. That water won't come back to the surface for quite some time, so the CO2 will be trapped there for quite some time. Therefore, we should pump that CO2 down into the ocean.

Answer Anticipation:
Aquaman will not be pleased.

There's both a main and intermediate conclusion here. While the argument is assuming CO2 in the atmosphere is bad, that's something the LSAT is probably going to say is a scientific fact, so I'm expecting the gap to be between the premise and intermediate conclusion, not the i. conclusion and main conclusion.

Looking at the premises, we see that the CO2 will be in water that won't surface for a while. However, does that mean the CO2 can't escape before that point? No! We've all had a soft drink of some kind - CO2 tends to bubble out of the water and float to the surface (don't think too much about the science). This argument is assuming that the CO2 will be trapped until the water comes near the surface.

Correct answer:
(C)

Answer choice analysis:
(A) Out of scope. Since the argument already tells us it will dissolve in this water, the relative ease of it doing so doesn't matter.

(B) If anything, the argument seems to assume that the CO2 will be released when it reaches the surface. The argument is about it staying dissolved in the deep water, not the surface water (where it won't be for centuries).

(C) Bingo. If we negate this and learn the CO2 will escape before the water surfaces, the entire argument falls apart.

(D) Out of scope. It doesn't matter why the CO2 dissolves since we know that it does.

(E) Out of scope. I think this answer choice is easier to analyze in its contrapositive form: If the CO2 won't be trapped for hundreds of years, we shouldn't pump it to the deep ocean. Takes for granted for granted that it will be trapped for hundreds of years, and that we should pump it to the deep ocean, so this answer choice is out of scope because it talks about an alternative world.

Takeaway/Pattern:
Don't get stuck in the science! Focus on the logic.

#officialexplanation

[andrewgong01]

Is "B" out of scope too because it talks about evaporation? If we negate "B" it also does destroy the argument by saying it will be released into the atmosphere but the stem said nothing about evaporation or can we infer evaporation does occur in the ocean?

Also, is "E" is a premise-booster too? It seems to be re-stating the question but adding in conditionals. I do see how there is a slight reversal in that it says If pump then then CO2 will be trapped; if CO2 not trapped then don't pump but that seems to help the case somewhat assuming that we can attain the sufficient conditions.

Now that I have written this, from hindsight, "E" seems more like a Justify-Principle/Justify Strengthen where we confirm that if we do pump CO2 we will know it will be trapped; therefore to reduce CO2 we should pump it?

[ohthatpatrick]

Negating (B) doesn't hurt the argument, because this author isn't selling his solution as a permanent fix, just one that will trap CO2 "for centuries".

If you negate (B), you're learning that CENTURIES LATER, this CO2 might escape via evaporation.

(E) is basically a reversal/negation.

The author's argument includes the move of
"Since the CO2 would be trapped there for hundreds of years, we should pump CO2 into ocean depths."
(CO2 trapped for 100s of years --> we should pump CO2 into ocean depths)

This answer choice gives us the reverse of that.

On ANY question type, it will be wrong when an answer choice that uses conditional logic gives us a conditional that says,
"IF the conclusion is true ..."