Question

The alternatives for ozone-depleting substances have caused for (i) Production of ozone in the atmosphere (ii) Increase in Greenhouse effect (iii) Increase in the production of compounds with high global warming potential Which of the statement(s) given above is correct?

• A. Only (ii) and (iii)
• B. Only (iii)
• C. Only (i) and (ii)
• D. All the above ((i), (ii) and (iii))

Answer 1

Answer:

A. Only (ii) and (iii)

• This question refers to the replacement of ozone-depleting substances (ODS) like CFCs. The common alternatives were Hydrofluorocarbons (HFCs).

  • (i) Production of ozone in the atmosphere: The alternatives (HFCs) do not directly cause the production of ozone in the atmosphere. Their primary role was to not deplete the ozone layer, which then allows the natural processes of ozone formation to continue without interference from ODS. So, they help in ozone recovery, but don't produce ozone themselves. This statement is subtly incorrect in its phrasing of "production of ozone".

  • (ii) Increase in Greenhouse effect: HFCs are potent greenhouse gases. While they don't deplete ozone, they contribute significantly to global warming. So, this is correct.

  • (iii) Increase in the production of compounds with high global warming potential: HFCs have a very high Global Warming Potential (GWP), often thousands of times higher than CO2. Their increased use as alternatives to ODS has indeed led to an increase in compounds with high GWP. So, this is correct.

  Therefore, statements (ii) and (iii) are correct