A current challenge related to ozone recovery is

• A. Emissions from old equipment have been fully eliminated by bans.
• B. Emissions from old equipment continue to release ozone-depleting substances and climate-forcing substitutes.
• C. There are no challenges remaining; ozone recovery is complete.
• D. Ozone depletion is no longer a concern for policymakers.

Answer: (B)

Ozone recovery is being made progress, but a real current challenge is that aging equipment still leaks ozone-depleting substances and that some substitutes chosen to replace them are potent climate forcings. Even though bans have reduced new emissions, old refrigeration, air-conditioning, and insulation systems still contain CFCs or HCFCs, and leaks during operation or improper disposal release these chemicals into the atmosphere. Those substances can destroy ozone and persist for a long time, slowing recovery. At the same time, the replacements used in place of those substances—while not always depleting ozone—often have high global warming potential, adding to climate-change concerns tied to the same chemical families. This combination means ozone recovery is not complete and faces ongoing obstacles.

Choices suggesting that bans eliminated all emissions or that there are no challenges overlook the reality of legacy stock and the climate impact of substitutes.