IC1318A butterfly nebula in Cygnus before: after AI enhance: so star is reduced a bit, nebolosity increased, and more smooth( less contrast) reference atlasofuniverse Achint Thomas
TLDR: Carbon Tetrachloride CCl4 (CTC), was major culprit , widely used and released to atmosphere well before CFC Gizomodo Nature MIT news Reference Montreal protocol 16th September ozone layer preservation day