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- Tue May 03, 2016 10:01 am
#23835
Complete Question Explanation
Resolve the Paradox. The correct answer choice is (D)
The ozone layer absorbs most of the ultraviolet radiation reaching the Earth’s atmosphere from the Sun. Even though that layer became thinner between 1969 and 1986, the average level of UV radiation reaching North America also decreased during that time. The correct answer choice will explain why the depletion of the ozone layer did not result in increased UV radiation at ground level.
Answer choice (A): Even though the harmful effects of UV radiation are well established, this observation does not help reconcile the apparently discrepant facts described in the stimulus.
Answer choice (B): The fact that the thinning of the ozone level over Brazil did have the anticipated effect of increased ground-level UV radiation does not explain why the same result was not observed in North America. This answer choice further deepens the paradox and is therefore incorrect.
Answer choice (C): What caused the thinning of the ozone layer is irrelevant. At issue is why the thinning of the ozone layer did not have the anticipated effect, not what caused such thinning.
Answer choice (D): This is the correct answer choice. If ozone pollution, which absorbs UV radiation, increased dramatically during that time, it isn’t surprising that the UV radiation at ground level decreased. If the effects of ozone pollution are strong enough to outweigh the negative effects of depleting the ozone in the stratosphere, this provides an alternate means of achieving the same result – lowering the ground-level UV radiation.
Answer choice (E): Just because the thinning of the layer of stratospheric ozone varies from location to location does not explain why the thinner layer over North America did not result in increased ground-level UV radiation at the same location. This answer choice would only explain the discrepancy if the measurements of stratospheric ozone levels were taken at a different location from the one used to measure ground-level UV radiation.
Resolve the Paradox. The correct answer choice is (D)
The ozone layer absorbs most of the ultraviolet radiation reaching the Earth’s atmosphere from the Sun. Even though that layer became thinner between 1969 and 1986, the average level of UV radiation reaching North America also decreased during that time. The correct answer choice will explain why the depletion of the ozone layer did not result in increased UV radiation at ground level.
Answer choice (A): Even though the harmful effects of UV radiation are well established, this observation does not help reconcile the apparently discrepant facts described in the stimulus.
Answer choice (B): The fact that the thinning of the ozone level over Brazil did have the anticipated effect of increased ground-level UV radiation does not explain why the same result was not observed in North America. This answer choice further deepens the paradox and is therefore incorrect.
Answer choice (C): What caused the thinning of the ozone layer is irrelevant. At issue is why the thinning of the ozone layer did not have the anticipated effect, not what caused such thinning.
Answer choice (D): This is the correct answer choice. If ozone pollution, which absorbs UV radiation, increased dramatically during that time, it isn’t surprising that the UV radiation at ground level decreased. If the effects of ozone pollution are strong enough to outweigh the negative effects of depleting the ozone in the stratosphere, this provides an alternate means of achieving the same result – lowering the ground-level UV radiation.
Answer choice (E): Just because the thinning of the layer of stratospheric ozone varies from location to location does not explain why the thinner layer over North America did not result in increased ground-level UV radiation at the same location. This answer choice would only explain the discrepancy if the measurements of stratospheric ozone levels were taken at a different location from the one used to measure ground-level UV radiation.