A theory held by some scientists is that the depletion of stratospheric ozone is substantial and will grow to alarming levels unless the use of CFCs and some related chemical compounds is eliminated. This theory led to an international treaty requiring that production of CFCs be rapidly phased out in developed countries. However, the theory of large-scale depletion caused by human use of these chemicals is not yet supported by solid scientific evidence.
For Complete Study: st191.pdf