Depletion of OzoneThe distribution of ozone in ionosphere, mesosphere and stratosphere is being depleted. The concentration of ozone is gradually reducing. As the content of ozone is highest in ionosphere and the air itself being very thin, the depletion is negligible in ionosphere. But in mesosphere and stratosphere the air is thicker and ozone content is less. The depletion of ozone is of higher order in these layers. The so called hole in ozone layers simply means that above some continents (specifically Antarctica, Asia and parts of South America) the mesosphere and stratosphere have lost their original level of ozone content.
The depletion of ozone layer is a global phenomena both in terms of cause and effect. The geographical limits of countries are not barriers to either dispersal of gases in layers of atmosphere or depletion of gases. The causes for depletion may arise in any country. The effects (in terms of depletion) may arise in any other country. The effects (in terms of ozone depletion) need not be exactly above the country causing the depletion.