What is the Montreal Protocol and why is it significant for atmospheric protection?

• A. An international treaty (1987) to phase out production and use of ozone-depleting substances; it has led to recovery of the ozone layer and protects against increased UV radiation.
• B. A climate treaty limiting CO2 emissions.
• C. A treaty about pesticide usage.
• D. A treaty on sea-level rise.

Answer: (A)

The essential idea is that this treaty is a global effort to stop the production and use of chemicals that destroy ozone in the stratosphere, thereby protecting the atmosphere from harmful ultraviolet radiation. Adopted in 1987 and strengthened over time, it requires countries to phase out ozone-depleting substances like CFCs and halons. When released, chlorine and bromine from these substances break apart ozone molecules, thinning the ozone layer that shields life from much of the sun’s UV-B radiation. By setting concrete phaseout schedules and helping developing nations switch to safer alternatives, the protocol created a practical path for international action. As a result, the atmospheric ozone is gradually recovering, reducing UV-related health risks (like skin cancer and cataracts) and environmental damage. This agreement stands out because it shows how coordinated global policy can effectively protect the atmosphere, unlike options that focus on climate change, pesticides, or sea-level rise.