Someone is working *really hard* to make this political. And a lot of people on both sides are buying it. Resulting in long essays like this one...
In the mean time (a) dual AC system for heat/cold is pretty standard in many European countries and (b) nobody is stopping you from doing anything.
If you can get hold of one, go ahead and install an AC. Install five for what I care. The inverter system is very efficient and you will probably not have the cold on for more than a few weeks per year anyway. And that during a time where Europe usually produces more power from solar panels than the infrastructure can handle..
Ignore whoever told you it's bad for the environment. Also ignore anyone who told you the green conspiracy is killing the elderly by the millions.
Now go and have a great summer.
Where I am from it is currently 24-25C at 3am. It will likely go up to 27C in August. We keep our AC on overnight in some evenings.
But most people I know run it mainly during the day, as it's cheaper on a dynamic contract (and basically free if you have solar panels). The heating during the night isn't high.
And we don't keep it at 18C or course, otherwise you get this slap in the face every time you leave the house.
I don't have AC (rental flat) and 25C is fine for the night. The problem is now when it's 31 in the house. I don't leave the windows open at night due to the cockroaches.
I don't see anyone moralising it anyway. On the contrary.