I _think_ a key difference between the montreal protocol and the paris agreement is that the first meant _banning products_, so a if country X keeps producing s

I _think_ a key difference between the montreal protocol and the paris agreement is that the first meant _banning products_, so a if country X keeps producing something with CFCs and tries to sell it to country Y then the latter can just forbid importing. So individual actors have an economical incentive to be compliant. This does not work for CO2 emissions, we're left to the individual countries' "goodwill".