Ozone layer protection, major objective of the world

In the paper, considerations on the destruction process of the stratospheric ozone by substances emitted by anthropogenic pollution sources and which reach in the stratosphere by transport from the troposphere are presented. In the stratosphere, the lifetime of these substances is less than in the troposphere. This time was calculated for the main substances which destroy ozone layer. In the same time are analysed the factors determining the natural variation of stratospheric ozone concentration