#6 - Scientist: There is a lot of concern that human

[Administrator]

Complete Question Explanation

Assumption. The correct answer choice is (B).

In this argument, the scientist claims that if humans are responsible for climate change, then humans can take control of the situation and make it better. There is a subtle shift between the concept of "responsible" in the premise and "control" in the conclusion, and we are asked to identify a necessary assumption of that argument. When we have a gap like this between the premises and the conclusion, we should look for a Supporter Assumption that closes that gap, connecting "responsible" to "control" in some way. A good prephrase here would be "humans can control whatever they are responsible for doing."

Answer choice (A): The author makes no assumptions about the degree of damage caused by one form of climate change or another. This answer does not remove a weakness in the argument, as a Defender Assumption would do, nor does it connect the premises to the conclusion as a Supporter Assumption should.

Answer choice (B): This is the correct answer choice. This answer appears to connect the dots for us, linking the idea of control to the premises. Although it does not use the word "responsible" as our prephrase did, it still captures the same idea, as it talks about human behavior having an impact. That should at least make this answer a contender as you first sort through them all.

Answer choice (C): As there is no mention of control in this answer, it fails to connect the rogue elements in the argument. Also take note of the certainty in the answer - our author does not claim that humans are responsible for climate change, but only makes the conditional claim that if that is true, then humans can take control of the situation.

Answer choice (D): The argument doesn't deal with the relative impact of climate change between species, and so this answer, which neither removes a problem nor closes a gap, is a loser.

Answer choice (E): Ease of identification of impactful behaviors is not relevant to this argument. The author didn't say it would be easy to take control, but only that humans could take control if they were, in fact, responsible.

[kev2015]

Hi,

I just have a question regarding the Dec 2014, LR part 2, #6. For this question, I first chose A, and then got it wrong, re-reviewed again, and then chose C, which was wrong again. It said that the answer is B. However I do not understand why it is not C? The argument/conclusion is "but this should be seen as more of an opportunity than a problem", and the premises should be "if human behaviour is responsible." . So since it says "if", isn't this supposed to be the assumption?

I am just really confused. Thanks a lot in advance!

[Laura Carrier]

Hi Kev,

You are right that this is a tricky stimulus due to the conditional nature of the final premise. But I think the source of your confusion will be easy for you to correct!

When the stimulus uses “if” to introduce the conditional premise in the last sentence, the scientist is not actually making an assumption that it is true that human behavior is responsible for climate change.

Instead, the scientist is essentially dividing the realm of possibilities into two regions: One scenario in which human behavior is responsible for climate change, and another scenario in which this is not the case. This premise tells us that, if the first scenario is true and humans are responsible for climate change, then humans can control future climate change to make it less extreme than previous climate changes. In this case, the scientist concludes that the possibility that humans cause climate change should be thought of as more an opportunity than a problem. But by using “if” to introduce the premise, the scientist doesn’t rule out the other possibility that human behavior is not responsible for climate change.

So, what if the other possible scenario is true, and human behavior isn't responsible for climate change? The stimulus doesn’t actually tell us anything about this possibility, so we don’t ever learn what the scientist would conclude if that scenario were true. So if you were to say, “But human behavior isn’t responsible for climate change,” the scientist would be able to reply, “Well, my argument isn’t even about that situation so it doesn’t affect my conclusion. I told you not to worry about the case in which human behavior does control climate change, since that control gives us the opportunity to ameliorate it.” Presumably, if human behavior didn’t cause climate change, there would be other reasons to dismiss the initial worry about human behavior causing large-scale climate change—but the stimulus simply remains silent about this possibility and offers a conclusion only about the first scenario in which humans can cause climate change.

When you are asked to select the answer choice that “the scientist’s argument requires assuming,” you need to choose a statement that is necessary to the argument’s conclusion, without which the conclusion couldn’t stand, since an assumption is an unstated a premise that must be true in order for the conclusion to be true. This question provides a perfect opportunity to use the Assumption Negation Technique to test out any contender answer choices by logically negating them in order to see whether they are really required by the conclusion!

As you pointed out, the conclusion is that we should regard human responsibility for climate change as more of an opportunity than a problem. Why? Because if it is true that human behavior is responsible for climate change, that means that humans can control and therefore reduce the extremity of future climate change.

Your initial choice, answer choice (A), is not necessary to this argument, because (A) concerns a different set of facts from those discussed in the stimulus. Whereas the stimulus is about controlling the degree of climate change by reducing its extremity, (A) talks about various levels of damage caused by the same degree of climate change depending on what caused it, a subject never discussed by the stimulus. If you have any doubt about (A)’s necessity to the argument, try negating it so that it says that the same degree of climate change does not produce less damage if it is caused by human behavior than if it has a purely natural cause. The negation doesn’t hurt the scientist’s conclusion that it would be a good thing if humans caused climate change because then we would have control over its degree, so (A) can’t be an assumption necessary to the argument.

Similarly, answer choice (C) is not an assumption needed by the scientist's argument because it is not necessary that any previous large-scale climate changes have been caused by human behavior. All the scientist discusses is the opportunity to impact the extent of future climate change so that it will be “less extreme than previous climate shifts.” For this to be true, it wouldn’t matter what caused the earlier climate shifts. All that matters is whether the degree of change can be lessened by human behavior in the future. So again, if we logically negate (C) and change “at least some” to say that “no previous large-scale climate changes have been caused by human behavior,” it doesn’t hurt the conclusion that human responsibility for large-scale climate change should be viewed as an opportunity for the future.

By contrast, answer choice (B) does state a necessary assumption: “Human beings can control the aspects of their behavior that have an impact on climate change.” Even if it is true that human behavior is the cause of climate change, if we negate (B) so that it tells us humans cannot control the aspects of their behavior that lead to climate change, it becomes impossible for the scientist to validly conclude that human responsibility for climate change is more of an opportunity than a problem. If the relevant behavior cannot be controlled, how could human responsibility for the problem been seen as an opportunity to affect the extremity of climate change by exercising that hypothetical but nonexistent control? Thus, (B) specifies an assumption that the scientist needs to believe is true.

I hope this clarifies things!
Laura

[mkarimi73]

Hello PowerScore! So, just to confirm, the conclusion of the argument is the second sentence of the stimulus: "But this should be seen as more of an opportunity than a problem." I ask because the original post from the Administrator seems to indicate that the last sentence is the conclusion. Just checking to make sure! Thanks in advance.

[Adam Tyson]

Correct, the second sentence is the conclusion and the last sentence is a conditional premise. The assumption here fills a gap in that premise.