The Montreal Protocol is signed to protect the ozone layer from depletion.

The Montreal Protocol, officially the Montreal Protocol on Substances That Deplete the Ozone Layer, is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 September 1987, and entered into force on 1 January 1989.

Since then it has undergone several amendments and adjustments, with revisions agreed to in 1990 (London), 1992 (Copenhagen), 1995 (Vienna), 1997 (Montreal), 1999 (Beijing), 2007 (Montreal), 2016 (Kigali) and 2018 (Quito).

Ozone Hole 2024 Update
Ozone Hole 2024 Update (Source: Wikimedia Commons)
Satellite map of ozone about Antartica
Satellite map of ozone about Antartica (Source: Wikimedia Commons)
Ozone cfc trends
Ozone cfc trends (Source: Wikimedia Commons)
TOMS Global Ozone 65N-65S
TOMS Global Ozone 65N-65S (Source: Wikimedia Commons)

Watch: The Hole - A film on the Montreal Protocol, narrated by Sir David Attenborough

From the UN Environment Programme channel.

Sources and further reading: Wikipedia — Montreal Protocol, Ozone depletion (CC BY-SA). Images: Wikimedia Commons.