In 1980 there was growing concern that the protective ozone layer over

Question

In 1980 there was growing concern that the protective ozone layer over the Antarctic might be decreasing and thereby allowing so much harmful ultraviolet radiation to reach the Earth that polar marine life would be damaged. Some government officials dismissed these concerns, since statistics indicated that global atmospheric ozone levels remained constant.

The relevance of the evidence cited by the government officials in support of their position would be most seriously undermined if it were true that

(A) most species of plant and animal life flourish in warm climates rather than in the polar regions
(B) decreases in the amount of atmospheric Ozone over the Antarctic ice cap tend to be seasonal rather than constant
(C) decreases in the amount of atmospheric ozone were of little concern before l980
(D) quantities of atmospheric ozone shifted away from the polar caps, correspondingly increasing ozone levels in other regions
(E) even where the amount of atmospheric ozone is normal, some ultraviolet light reaches the Earth’s surface

daagh · Answer

B must be the answer since the evidence that the protective layer of Ozone is a fluctuating one rather than a constant one nullifies the officials claim.

ArtVandaley · Answer

D is the answer here. Even if the average remain same, there is a good chance that the layer's thickness is increasing at one place and decreasing at another.

Posted from my mobile device

Jaffer99 · Answer

Guys can someone conclusively explain why D is the answer and not B. Does not seem to be a clear explanation here. I speculate it is some subtle detail that my idiot mind missed.

Jaffer99 · Answer

Bunuel  could you please explain?

Sudhanwa23 · Answer

In my opinion, why the correct answer is D is because, 
D suggests that the ozone layer is actually decreasing more in the poles and that amount is shifted to other sides of the globe. Since government is looking only at the global level of ozone, it will seem constant, though in reality its not the case in poles. So, D undermines the governments statement.

I hope my reasoning is clear

agrasan · Answer

Hi  KarishmaB   MartyMurray   DmitryFarber

Could you please hep to eliminate (B)?

My reasoning for (B) is it does not show that the officials’ statistics are misleading or irrelevant. If the decrease is  only seasonal , then it may  average out  over the year and could easily be consistent with  constant global ozone levels . Is this the right way to think and eliminate (B)?

AbhishekP220108 · Answer

Hi  agrasan , let me try to help.

Let's first look at the argument:

1. A concern related to the decrease in ozone protection over Antarctic was presented.
2. Govt officials are saying the concern is not valid. The reason for dismissal is global ozone level is constant.

Ques asks to weaken the relevance of the evidence provided by the government officials.

Think of the relevance—it was related to concern; we have to weaken the dismissal given by officials that, even though the global ozone layer is constant, the concern is still valid.

So any option choice that relates to the global ozone level being constant and concerns related to antarctic region.

Why option B is not correct-  (B) Decreases in the amount of atmospheric Ozone over the Antarctic ice cap tend to be seasonal rather than constant.  While this suggests the depletion isn't permanent, it doesn't explain how the  global  levels remained constant. Furthermore, even a seasonal decrease is a decrease.

In 1980 there was growing concern that the protective ozone layer over

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In 1980 there was growing concern that the protective ozone layer over

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