Italy has changed, African anticyclones dominate

The Italian climate has changed drastically in recent years due to global warming, and the consequences are extreme weather events such as the flood that caused the Frejus river to overflow in Bardonecchia. "The problem is that in the Mediterranean and southern Europe, not only has the average temperature increased, but also the air circulation," Antonello Pasini, climate physicist at the Institute of Atmospheric Pollution of the National Research Council, told ANSA.

"Our summers, until a few decades ago, were dominated by the famous Azores anticyclone, a cushion of stable air that protected us all summer until mid-August - says Pasini - when the summer storms began". Now this is no longer the case: the climate crisis has modified atmospheric circulation and the Azores anticyclone has been ousted by African anticyclones, which however have less favourable characteristics. "They are much warmer and also less stable", explains the CNR expert: "They do not cover Italy well on the northern edge and when they retreat, cooler currents enter, in the case of Bardonecchia from the French side, and these air contrasts of a different type create very violent precipitation. Furthermore - adds Pasini - the contrasts become increasingly higher, because unfortunately the heat is increasingly stronger".

This is the phenomenon currently underway, and also in the coming days, in Northern Italy in general. For Bardonecchia, in particular, other causes also come into play: "Our Alpine valleys are very narrow - comments Antonello Pasini - with torrential rivers that are dry for most of the year, and that suddenly fill up due to events of this type". Climate change caused by human activities is therefore the driver of these extreme weather events that are becoming increasingly frequent and intense. "We will have to endure them for the next few decades", underlines the climate physicist.

"On the one hand we have to adapt, for example by avoiding building too close to river banks and renaturalizing a part of the territory. On the other hand we must absolutely avoid arriving at much worse future scenarios - concludes Pasini - because we would probably find ourselves in unmanageable conditions".