Short answers, pulled from the story.
Thomas Midgley Jr. of General Motors synthesized the first chlorofluorocarbons prior to 1930 during a collaborative effort between Frigidaire, General Motors, and DuPont. The Frigidaire corporation received patent number 1,886,339 on the 31st of December 1928 for these compounds.
Sherry Rowland and Mario Molina published research suggesting the connection between CFCs and ozone damage in 1974. This research identified that chlorine atoms behave differently from chlorine molecules and are long-lived in the upper atmosphere where they catalyze the conversion of ozone into oxygen.
Twelve European Community nations agreed on the 2nd of March 1989 to ban production of all CFCs by the end of the century. Diplomats met in London in 1990 to strengthen this protocol calling for complete elimination of CFCs by 2000.
Chlorofluorocarbon absorption bands occur between 7.8 and 15.3 micrometers referred to as the atmospheric window which has relative transparency allowing unique susceptibility to radiation absorption. Low concentration of each individual CFC intensifies this super greenhouse effect compared to carbon dioxide because carbon dioxide is close to saturation with high concentrations while CFC effects increase linearly with mass.
James Lovelock detected widespread presence of CFC-11 over Ireland finding a mole fraction of 60 parts per trillion during an expedition ending in 1973. He measured CFC-11 in both Arctic and Antarctic air samples during that same period.