Former UN Secretary-General Kofi Annan once stated that ‘perhaps the single…

CONCEPT

An attribution question is resolved by matching the exact wording to its documented speaker and source. Environmental instruments can also be distinguished by subject: ozone protection, greenhouse-gas targets, broad sustainable-development commitments, or nationally determined climate action.

APPLICATION

In his report We the Peoples, Kofi Annan used this description for the Montreal Protocol and immediately linked the agreement with phasing out ozone-depleting substances. That subject matches the Montreal Protocol, adopted in 1987 under the Vienna Convention framework.

CONTRAST

• Rio Summit — a 1992 conference associated with the Rio Declaration and Agenda 21.

• Montreal Protocol — an international agreement controlling ozone-depleting substances.

• Kyoto Protocol — a 1997 climate instrument with emission-reduction commitments for specified developed countries.

• Paris Agreement — a 2015 climate framework based on nationally determined contributions.

CROSS-CHECK

The words following the quoted description refer to the phase-out of ozone-depleting substances, which independently identifies the Montreal Protocol rather than the climate instruments or the Rio conference.

Therefore, the agreement named in the quotation is the Montreal Protocol.