This is not a good argument. AC is needed every summer for some years now for much of northern europe, the only question is how many days per year. The last heatwave was not in 2003.

You do not need AC in every house necessarily. You need ACs in public buildings and in places that matter for the most vulnerable population. You need at least places this population can go during the hottest part of the day.

Solutions are known in places where heatwaves are common place, but somehow northern europe takes time to realise that they are actually solvable.