Explanation:

The aim of the 1985 Vienna Convention is to conserve human health and to secure the environment from any harmful impacts of the depletion of the ozone layer. The aim of the 1987 Montreal Protocol is to preserve the ozone layer throughout the worldwide control, reduction and ultimately elimination of the production and consumption of the ozone-depleting substances. The recent extension of the Montreal Protocol in 2016 – the Kigali Amendment – controls hydrofluorocarbons as well. These chemicals are presently in use as a substitute for the ozone-depleting substances but are themselves potent greenhouse gases.

• The Vienna Convention supports and encourages research activities, cooperation and the exchange of information between the states, and national legislative measures, without however determining any concrete measures. 

o Adoption: 1985

o Entry into force in Switzerland: 22 Sept. 1988

• As many of the substitute chemicals (HFCs) are potent greenhouse gases with an impact more than a thousand times stronger than that of CO2 and thus contribute to the global warming, the Parties to the Montreal Protocol resolved in the October 2016 in Kigali (Rwanda), to expand the Montreal Protocol to HFCs (Kigali Amendment), and to decline the production and consumption of these chemicals by 85 percent in the medium term. These provisions will came into force from 1 Jan. 2019.

o Adoption of the Protocol: 1987, and of its amendments: London: 1990; Copenhagen: 1992; Montreal: 1997; Beijing: 1999; Kigali, 2016

o Ratification by Switzerland of the Protocol: 1988 and of its amendments: London: 1992; Copenhagen: 1996; Montreal and Beijing: 2002

o Worldwide ratification (Montreal Protocol and its first four amendments): 2014