It is not just the energy usage but also the refrigerants used. Most common refrigerants used in AC systems are pretty bad GHG'es themselves, often 2,000x worse than CO2.
Are many small portable AC units these days running 1234yf yet?
I'm pretty sure most portable ACs sold in Europe these days are R290 (propane) which has a GWP of about 1/14th of CO2, so for those that's no longer much of a concern.
R290 has a GWP of 3.3, so that's 3.3x worse than CO2 with a GOP of 1. Which makes sense, because when propane breaks down it usually breaks down to CO2.
Thanks for sharing that portable AC's in Europe are R290, I don't think that's super common in the US. But I'm open to being shown wrong on that!
Are many small portable AC units these days running 1234yf yet?