The Montreal Protocol was signed in order to address which of the following environmental issues?

The Montreal Protocol was signed to tackle depletion of the ozone layer in the stratosphere by controlling ozone destroying chemicals.

Tropospheric ozone pollution at ground level is a separate air quality issue not addressed by this treaty.

Global warming is dealt with mainly through climate treaties such as the Kyoto Protocol and Paris Agreement.

Acid rain is caused by sulphur and nitrogen oxides and is governed by different pollution agreements.

The protocol phased out substances such as CFCs and halons that release ozone destroying chlorine and bromine.

Agreed in 1987, it is often cited as the most successful global environmental treaty.