[bzxcvbn]

> They are sealed systems. They only emit gasses when breached. Or when not properly disposed of.

And mechanical devices having leaks is a folklore tale told to scare children?

> A few watts - whatever power it requires to operate. Say it uses 1.5kw. That's the max it will heat up the city.

Yeah. 1500W. Times the number of AC units in the city. That's what adds up to the temperature difference between the city and the countryside.

> If you power AC units with sunlight...

...with a solar panel above your own home, with no inefficiency in the electrical grid, the solar panel, or the AC unit itself. Please, this isn't a high school physics exam, you can't assume that there is no friction or that the AC unit is spherical. This is real life.

[brnt]

Take a look at heating if you want to see staggering energy consumption numbers. In a majority of places, people don't use heat pumps with a COP of say 4-5, but convert chemical energy with a cop of 0.5-0.9.

[dragonwriter]

> That's what adds up to the temperature difference between the city and the countryside.

No, most of the difference is albedo difference meaning urban areas capture more radiant solar energy.