Ans.

By the 1970s, concern was growing that the Earth’s stratospheric ozone layer, which protects the earth against excessive ultraviolet radiation, was being destroyed – which would cause damage to humans, plants, and animals.

The objective of the 1985 Vienna Convention is to preserve human health, and to protect the environment from any harmful effects of the depletion of the ozone layer. The objective of the 1987 Montreal Protocol is to preserve the ozone layer through the worldwide control, reduction and ultimately elimination of production and consumption of ozone depleting substances. The latest extension of the Montreal Protocol in 2016 – the Kigali Amendment – regulates hydrofluorocarbons as well. These chemicals are currently in use as a substitute for ozone-depleting substances, but are themselves potent greenhouse gases.