What affect does the regular use of A/C contribute to global warming?

[werdna]

20. And the scientists say -

https://www.scientificamerican.com/article/how-to-prevent-air-conditioners-from-heating-the-planet/

One of the great ironies of climate change is that as the planet warms, the technology that people need to stay cool will only make the climate hotter. By 2050, researchers expect the number of room air conditioners on Earth to quadruple to 4.5 billion, becoming at least as ubiquitous as cell phones are today. By the end of the century, greenhouse gas emissions from air conditioning will account for as much as a 0.5-degree Celsius rise in global temperatures, according to calculations by the World Economic Forum.

. . .

In November 2019, eight finalists were announced for the $1 million competition to design a room air conditioner that produces five times less greenhouse gas over the course of its lifetime than does a standard room unit.

The details are in the article at the attribution link above.