Destruction of ozone in the stratosphere
The stratospheric ozone layer protects the Earth’s biosphere from a large part of the Ultraviolet radiation emitted by the Sun.
Appearing in the beginning of the 1980s, two spectacular phenomena demonstrated that certain human activities threatened this natural protection against ultraviolet rays:
- the destruction of almost all of the ozone in the lower Antarctic stratosphere each spring (ozone hole)
- the destruction of 3% each decade of the ozone layer at Northern latitudes
Montreal protocol on ozone depleting substances
In September 1987, the Montreal Protocol was established in reaction to these alarming discoveries.
It has since been regulating the production and use of many chemical substances that release, in the stratosphere, chlorine and bromine, which are responsible for the ozone destruction.