A research group from the British Antarctic Survey who were monitoring the atmosphere above Antarctica first noticed dramatic loss of ozone in the lower stratosphere there in the 1970s.

This is mainly due to the release of manmade chemicals containing chlorine such as CFC's (ChloroFluoroCarbons), as well as compounds containing bromine, other related halogen compounds and also nitrogen oxides.

CFC's are a common industrial product, used in refrigeration systems, air conditioners, aerosols, solvents and in the production of some types of packaging.

Nitrogen oxides are a by-product of combustion processes, eg aircraft emissions.

The current levels of depletion have served to highlight a surprising degree of instability of the atmosphere, and the amount of ozone loss is still increasing.

© 2005 Al Bawaba (www.albawaba.com)