The depletion of the earth stratospheric ozone layer as a result of the catalytic destruction of ozone by atomic halogens. The main source of these halogen atoms in the stratosphere is photodissociation of man-made halocarbon refrigerants, solvents, propellants, and foam-blowing agents (CFCs, HCFCs, freons, halons). The earth's stratospheric ozone layer plays a critical role in absorbing ultraviolet radiation emitted by the sun. (Source: InforMEA/MMA based on Wikipedia)