AC doesn't really create heat though, aside from minor amounts from the compressor/fan motors, it merely moves it from inside to outside, or into the metro stations as you mention.
The roof on the house (assuming 29N because the article is about Houston, so between 10AM and 2PM, that's a Solar irradiance of 1kW/m^2) is receiving 157.9kW of sunlight, and then absorbing about 85% of that.
My point is that it doesn't create heat, thus does not contribute to climate change on its own. Only the energy source that powers it potentially does.
Since ACs are pretty far from 100% efficient, they turn electricity into heat. There's also heat generated along with the electricity because generation isn't perfect either.