Question

Thinning of ozone layer due to catalytic destruction of stratospheric ozone is more prominent over north pole (Arctic) compared to south pole (Antarctica). The direct emission of CFCs (ozone depleting substances) in stratosphere are more in northern hemisphere compared to those in southern hemisphere of the Earth. Which of the following is most appropriate?

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

More CFC emissions (northern hemisphere) $\rightarrow$ greater ozone-depleting substance concentration $\rightarrow$ more Arctic ozone thinning.

Answer 1

The Correct Option is A

Step 1: Concept
Stratospheric ozone depletion: Arctic vs. Antarctic and the role of CFCs.

Step 2: Meaning
CFC emissions are higher in the industrialised northern hemisphere, leading to greater ozone depletion over the Arctic.

Step 3: Analysis
Statement (A): Ozone thinning is more prominent over the Arctic --- this is supported in the context of the question.
Statement (R): CFC emissions are higher in the northern hemisphere (more industrial activity) --- correct.
Higher CFC concentrations in the north $\Rightarrow$ more ozone-depleting reactions $\Rightarrow$ greater Arctic ozone thinning. Hence (R) explains (A).

Step 4: Conclusion
Both (A) and (R) are correct, and (R) is the correct explanation of (A). Final Answer: (A)