The Kigali Amendment was adopted on October 15, 2016, in Kigali, Rwanda. It aimed to phase down the production and consumption of hydrofluorocarbons (HFCs), potent greenhouse gases, marking a significant step in global efforts to combat climate change while continuing to protect the ozone layer.

In 2007, parties to the Montreal Protocol agreed on accelerated phase-out schedules for HCFCs during a meeting in Montreal. This adjustment aimed to reduce the production and consumption of HCFCs more rapidly, contributing to the recovery of the ozone layer and mitigating climate change.

The Beijing Amendment was adopted on December 3, 1999. It introduced controls on the production and consumption of hydrochlorofluorocarbons (HCFCs) and added bromochloromethane to the list of controlled substances, further strengthening global efforts to protect the ozone layer.

The Montreal Amendment was adopted on December 5, 1997, in Montreal. It introduced a licensing system for the import and export of controlled substances to prevent illegal trade and further enhanced the protocol's effectiveness in protecting the ozone layer.

The Copenhagen Amendment was adopted on November 23, 1992, further strengthening the Montreal Protocol. It accelerated the phase-out schedules for CFCs and halons and introduced controls on additional substances like methyl bromide, which also contributed to ozone depletion.

The London Amendment to the Montreal Protocol was adopted on June 29, 1990. It introduced new controls on additional ozone-depleting substances and established a financial mechanism to assist developing countries in meeting their commitments under the protocol.

The Montreal Protocol officially entered into force on January 1, 1989. This marked the beginning of legally binding commitments for countries to phase out the use of ozone-depleting substances. The protocol has undergone several amendments to include more substances and accelerate phase-out schedules.

On September 16, 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer was adopted. It aimed to phase out the production and consumption of numerous substances responsible for ozone depletion, primarily chlorofluorocarbons (CFCs). The protocol is considered one of the most successful environmental agreements.

The Vienna Convention for the Protection of the Ozone Layer was adopted on October 24, 1985. It provided a framework for international cooperation to address the depletion of the ozone layer, setting the stage for future protocols and amendments aimed at reducing ozone-depleting substances.

In March 1985, British Antarctic Survey scientists discovered a significant depletion of the ozone layer over Antarctica, commonly referred to as the 'ozone hole'. This discovery highlighted the adverse effects of chlorofluorocarbons (CFCs) on the ozone layer, leading to global concern and action.