If someone were to tell you that R-134a is ozone unfriendly, that would indeed be BS. However, R-134a (CH2FCF3) is being phased out because it is a greenhouse gas, like most hydrofluorocarbons (HFC's), and can absorb infrared radiation. HFCs also have a relatively long lifetime in the atmosphere. A molecule of HFC-134a has a greenhouse contribution roughly 30% that of a molecule of CO2, CO2 being one of the two most important greenhouse gases (the other being water vapour).
James