Freon was phased out due to it’s effect on the ozone layer. The new ozone-friendly refrigerants have been found to be potent greenhouse gasses. So, now they have some new new refrigerants that are presumably ozone and greenhouse friendly. When a few hundred million people switch over, they will reveal the downside of this new stuff. It probably causes cancer.
But I pass more gas myself in twenty years than my air conditioning unit.