I definetely understand that this feature of Europe heating the most is a bit contra-intuitive as you pointed out. But the thing is that climat is dictated by a series of factors, not only the lattitude of a city, as an example we can cite the direction of the wind, the angle of solar exposition, the streams in the ocean and this gives rise to this very complex phenomen.

Regarding tourism it is true that it can have a local effect, specially when we talk about mass tourism like in Venice, but Climate change is a global phenomen.