When, exactly, did the ozone hole first appear?

there no *exact* answer. can document when have observed it.

ozone hole has occurred every year, 500 million years (the great oxidation event). earth has had *some* contaminants in air , axial tilt, hole of size had occur.

expected exist / predicted, around turn of last century.

discovered when uv distant stars made through hole, photographed @ earth's surface.

has done gotten large asia, , reduced less 1/3 normal total column ozone level, not have happened without intervention of man.

i googled it, several different answers appeared. wan t know is; whether ozone hole started appear recently, (within last hundred years), or if started appear before (many centuries ago)?

Science & Mathematics Earth Sciences & Geology Next