I agree with your second paragraph... many things are larger contributors of several of the world climate problems including Cow Emissions... and I am not kidding..

However, with regards to R-12 , since our old cars were made to run with it, I prefer to think about the larger problems while cold air is blowing in my face from the center vent. LOL

All my other vehicles use R134a and have plenty cold air conditioning. If I had the time and money to put a GM 6 piston compressor and P-Flow condensor into my 240 I would use R-134a myself.

In the past it was usually R-11 which was used for flushing ... but individuals can mess up... or declare an emergency ( some times just in their own mind ) with regards to military missions ...and stuff like that happen.