Which one of the following is associated with the issue of control and phasing out of the use of ozone-depleting substances?

Answer: (b) Montreal Protocol

The Montreal Protocol (1987) phases out ozone-depleting substances like CFCs.

The idea

CFCs are very stable, so they drift up to the stratosphere unchanged. There ultraviolet light breaks them and frees chlorine. One chlorine atom destroys thousands of ozone molecules. The only cure is to stop making these chemicals, and that is what the Montreal Protocol does.

CFCs released from fridges, ACs and sprays → Rise to the stratosphere → UV light frees chlorine → Chlorine breaks ozone again and again → More UV reaches the ground

Why the others are wrong

(a) Bretton Woods (1944) created the IMF and World Bank.

(c) Kyoto (1997) is about greenhouse gases.

(d) Nagoya (2010) is about access and benefit sharing of genetic resources.

The trap

Kyoto is the other famous protocol — but for greenhouse gases.

Also know

It is the first UN treaty ratified by every country, and the ozone layer is now slowly recovering. CFCs were replaced by HFCs, which do not harm ozone but are strong greenhouse gases. The Kigali Amendment (2016) phases HFCs down; India will cut them by 85% by 2047. A Multilateral Fund helps developing countries pay for the change.