“Arrived in Bologna, Italy, today, now it’s off to Tuscany. The heatwave is spectacular here. If things continue like this, these holiday destinations will have no future in the long term. Climate change is destroying southern Europe. An era comes to an end.” This tweet in early July by Karl Lauterbach, Germany’s health minister, went down badly in Italy. The country’s minister for tourism, Daniela Santanchè, sourly retorted that…