Yes, it very effectively moves the heat into the surrounding area, and in more densely populated areas can raise temps by around 4 degrees.
Do you think the people currently installing aircon in the UK will only run it when temps reach extreme/dangerous levels, or will they develop the habit of using it at cooler temperatures - which they previously could have endured with minimal discomfort; or could have handled with more passive measures like insulation, shutters, awnings, tree cover etc. How does that efficiency compare?
I'm not saying that AC isn't something that some people/households in the UK legitimately require, but for the vast majority this has not been the case, and may not be the case for some years yet.