Walking in the rain

We notice the rain especially when it is absent for too long. So words like drought and desertification scare us. Furthermore, we realize how polluted our cities are when they are not washed by Jupiter Pluvius for a long time. At the same time, rain is now the summer scare, in this era of climate change. Then expressions like "water bomb" become commonplace and with every downpour we fear the Apocalypse.

Yet, there is no atmospheric phenomenon more common and frequent than rain, in all its different manifestations: drizzle, droplets, snow, hail. It is part of the life that flows on our planet. Indeed there would never have been life if rains lasting centuries, hundreds of millions of years ago, had not given life to the oceans and seas. Indeed, without the rain which made the ground a mud quagmire and prevented the French army from attacking quickly and vehemently, Napoleon would probably have won at Waterloo in 1815! And what, if not the rain, made a decisive contribution to wiping out the plague from Milan at the end of The Betrothed?

In short, the Earth and also a large part of human history and culture - think of the great story of the universal Flood common to many cultures - have taken the shape that we know drop by drop. Vincenzo Levizzani , research director of the Institute of Atmospheric and Climate Sciences of the Cnr of Bologna, tells us about it in his “ Quando Outside It Rains ” (Il Saggiatore, 2024, pp. 296, also e-book).

In the book Levizzari reconstructs the past, present and future of a phenomenon to which we have been accustomed since birth , but which remains the most mysterious and elusive of meteorological events . Certainly one of those who, since we were children, has asked us incessant questions: why does it rain at a certain time? Why is rainfall always different? Sometimes we are hit by short-lived downpours, other times the rain is light and continues for hours and hours: how then can we say that it rained a little or a lot? How do we quantify rain?

These are questions to which Levizzari provides an answer - sometimes several answers - in his book, telling us the secrets of atmospheric precipitation and how humanity, over the millennia, has experienced and faced them.

Understanding how precipitation works does not just mean being able to interpret weather forecasts, but exploring the mechanism that underlies the existence of flora and fauna on our planet. Knowing more allows us to preserve the extremely delicate dynamics that make life on Earth possible. Never like in our era, rain is life and it is the future.