Ozone Depletion | The Montreal Protocol

Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage.

The Montreal Protocol on Ozone Layer Depleting Substances is an international treaty established to ensure that measures are taken to undo the damage to the ozone layer of the Earth to deter further damage. In 1987, it was signed. This document established limits on chemicals considered to be harmful to the defensive shield provided to Earth by the ozone layer. The harmful UV rays of the sun would change our atmosphere so radically without the ozone layer, that life on lan