In the atmosphere.
See "Why is an ozone hole formed only above Antarctica and not over developed countries that emit a lot of CFCs?"
The ozone is present in the Antarctica region of globe. It is because ozone depletion requires very less temperatures.
Stratospheric pollution means depletion of ozone layer (ozone hole) by certain compounds like CFCs, oxides of nitrogen .
See "What is causing the depletion of the Ozone Layer?"in the "Related questions" section below.
There is not actually a hole in the ozone layer but it is the thinning of ozone layer below a certain level. However the ozone in the ozone layer gets depleted and repaired by itself through natural phenomenon. However due to the use of CFC's by the human beings the rate of depletion has increased than the rate of repairing and thus the levels of ozone are falling down at a continues rate.
High ozone levels are by lightening. Soldering also produces ozone.
The ozone depletion is greatest at the poles. It is due to the cold temperatures there.
The greatest natural cause of ozone depletion is UV rays. But they also replenish it.
The CFC's have greatest effect. They react with ozone to deplete it.
Chlorofluorocarbons (CFCs)
Ozone depletion occurs in the ozone layer.
Ozone depletion is the depletion of ozone molecules. It is happening because of CFC's.
The major cause of ozone depletion is the reaction of CFC with ozone. They decompose ozone and cause its depletion.
Ozone depletion refers to the depletion of ozone molecules. These molecules are present in the ozone layer.
The solution for ozone depletion is curbing CFC's. They could prevent ozone depletion.
Ozone depletion is due to CFC's. They react with ozone to deplete it.
Ozone depletion is the thinning of ozone layer below a certain concentration. This phenomenon is termed as ozone depletion.
Global warming and ozone depletion are not related.