Which statement best contrasts regulatory approaches to ozone depletion (Montreal Protocol) and climate change (Paris Agreement) in terms of sector focus and mechanisms?

• A. Montreal Protocol targets ozone-depleting chemicals across sectors with specific phaseouts; Paris Agreement targets greenhouse gases with nationally determined contributions and market mechanisms.
• B. Montreal Protocol and Paris Agreement both set fixed global emission caps.
• C. Paris targets ozone-depleting chemicals; Montreal Protocol targets greenhouse gases.
• D. Montreal Protocol uses carbon trading; Paris uses sector-specific phaseouts.

Answer: (D)

The main idea is that these two treaties regulate different issues using different approaches. The Montreal Protocol targets a specific set of ozone-depleting chemicals and does so across many industries and products. It uses clear, legally binding phaseouts and schedules to eliminate those substances, with controls that apply across sectors such as refrigeration, solvents, and foam blowing agents. In contrast, the Paris Agreement centers on greenhouse gas emissions from the whole economy. Countries write their own nationally determined contributions, choosing their own targets and timelines, and the framework allows flexible, market-based tools to help meet those goals. So the contrast is sector-wide, substance-specific phasing for ozone-depleting chemicals versus economy-wide, country-driven targets with market mechanisms for climate change.