#11 - Nature constantly adjusts the atmospheric carbon level

[Administrator]

Complete Question Explanation

Weaken. The correct answer choice is (E).

Answer choice (A): This answer does not weaken the argument. According to the stimulus, carbon levels increase and decrease, but carbon appears to be a constant component of the atmosphere, so plant life is not in danger of having to survive without it anyway.

Answer choice (B): This answer strengthens the argument. The main point of the argument is that the environmentalists need not worry, and this answer choice lends that argument credibility.

Answer choice (C): This answer is similar to answer choice (A) in that it gives us one reason to be thankful for carbon. Since carbon seems to be regulated, its elimination doesn’t appear to be a concern.

Answer choice (D): This answer doesn’t weaken the argument, since the animals are only a part of the bigger picture, which allows nature to regulate the level of carbon in the atmosphere.

Answer choice (E) is the correct answer choice. If the adjustment process allows for wide fluctuations in the atmospheric carbon level, and we know from the stimulus that a sustained increase would threaten human life, then it seems that the environmentalists do indeed have cause for concern.

[PositiveThinker]

Hello, this question kind of has me confused, answer choice B says "it is not clear that breathing excess carbon in the atmosphere will have a negative effect on human life."

How wold being unaware of potential danger strengthen a concern? Minimal or no evidence of a threat doesn't mean there isn't one. I feel like that answer choice can be seen as a weakening or strengthening. I picked it as a weakening because the possibility of inhaling excess carbon having a negative effect was a possibility.



I sort of see how E is right. But not because of the reason you pointed out. I feel like E is saying "the adjustment process taking millions of years" is more damaging to human life. If the adjustment takes that long we are all doomed. Wouldn't we need a faster adjustment in order to survive? How does wide fluctuations make life on earth more dangerous?

I know this is a very old test but if i could get some help that would be wonderful.

[Francis O'Rourke]

Hi PT,

You are right that no evidence of a threat doesn't mean there isn't one. However, it also does not mean that there is a threat:-D


Imagine that you said to me: we should worry about breathing in all this added carbon. If I wanted to tell you to "relax" I could point to the same information that Choice (B) does: there's no clear evidence that breathing in this extra carbon will harm us. In other words, relax, this worry is not proven. In this way, Choice (B) strengthens the opinion that we should relax about the issue.


The author inferred that if nature is constantly adjusting itself, then an increase here or a decrease there in carbon levels wouldn't affect us greatly. Choice (E) directly weakens this inference: while it is true that nature is adjusting itself, we may not feel the benefits of that adjustment until after human life is harmed by the wide fluctuation in atmospheric carbon and heat levels.

[PositiveThinker]

ahhh now it makes sense. LSAT makers love to be difficult. Parsing out the convoluted grammar and understanding whats being said is so important.

[andriana.caban]

How is this not causal reasoning?

Increase in the [carbon] levels atmosphere holds more heat more water to evaporate from the oceans increased rain?

I'm still trying to identify when an argument has causal reasoning, since I haven't gotten to that chapter in the LR Bibles yet I'm struggling a little. Thanks!

[Adam Tyson]

I think there is some causal stuff happening in the stimulus, andriana.caban, although I wouldn't diagram it with arrows as you did, because I wouldn't want to confuse causal reasoning with conditional reasoning. You'll see when you get to that chapter that we generally avoid arrows (and mostly don't diagram conditional reasoning at all), but instead, if we are going to diagram, we just label them with "c" for cause and "e" for effect.

The reason we don't use causal analysis on this argument is that the conclusion is not a causal one. We have a whole lot of cause and effect in the stimulus, but the conclusion isn't "therefore, this causes that" or "therefore, this does not cause that." Instead, the conclusion is just "hey man, relax, there's nothing to worry about." To weaken that, we don't want or need to focus on the causal issues. Instead, we want to prephrase and then pick an answer that says that maybe we should NOT relax, because maybe there IS something to worry about! Find the reason to worry, and that's your best answer choice. Answer E gives us a reason to worry because the earth's natural adjustment to increased carbon levels can take a really, really long time, and we might not be able to afford to wait all that long! By the time the planet self-corrects we might have gone the way of the dinosaurs!

The presence of causal reasoning does not, by itself, make the argument causal, just as the presence of conditional reasoning does not, by itself, make the argument conditional. Check out the structure of the argument, including the type of conclusion and how the premises supposedly support it, and use that to determine how you will proceed from there. Good luck, and enjoy that chapter on causal reasoning when you get to it! It's eye-opening!

[LSAT2020]

I struggled to understand what answer choice E was saying. Is it saying:

Yes, the Earth does continually adjust to the carbon levels (as stated in the last sentence of the premise). However, you MUST keep in mind that this happens over millions of years.

The part about the "wide functions in the short term" really seemed to throw me off.

Would greatly appreciate any input:)

[Jeremy Press]

Hi LSAT2020,

You're right about the basics of answer choice E! If the carbon-level adjustment process takes millions of years to occur, and there could be wide fluctuations in carbon levels in the short(er) term, what does that mean? That means we could face significant dangers from fluctuating carbon levels in the time period between those millions-of-years long adjustments. A reason to be worried, for sure (and an attack on the argument)!

I hope this helps!

Jeremy