R-134A has a global warming potential of 1550 over 100 years [1], i.e. about 45 times more effective than methane, so while it's not eating the ozone layer you probably shouldn't be spraying it around by the tonne either.
Edit: and CO2 has a GWP of 1 (as the reference point for GWP), so R-134A is way more effective than that.
Edit: and CO2 has a GWP of 1 (as the reference point for GWP), so R-134A is way more effective than that.
1: https://en.wikipedia.org/wiki/Global_warming_potential#Value...