Water

Is a forecast possible?

Since glaciations depend, among other things, on the cyclic changes of the Earth’s orbit around the Sun, according to astronomic data, our planet is about to enter a cold period. Some of the “experts” in the sector, therefore tend to forecast the onset of a new glacial era, with ice once again covering territories that were occupied 20,000 years ago (including Central Park in New York and part of the Po valley right up to the outskirts of Milan…). However this “natural” trend  is opposed by the progressive heating of the Earth’s atmosphere, due to an increase in the greenhouse gases mostly due to human activities. If, on one hand, the increase in the cloudy covering, as a consequence of the greater amount of evaporation due to heating, prevents the Earth from dispersing heat, favouring further heating, this blanket of clouds can shield solar radiation, decreasing the amount that reaches the surface. Also the emission of large quantities of dusts and volcanic ashes can act as a shield against solar radiation, favouring the cooling of the atmosphere : an increase in volcanic activity may mitigate or even annul the greenhouse effect. There are numerous factors involved, and the creation of a forecast model bearing in mind all the interactions between contrasting factors is practically impossible. When meteorological phenomena affect us closely we  obviously tend to give them great importance, but it must not be forgotten that if on the human life scale a year or a decade may seem a long period of time, on the life scale of the Earth, which is 4.6 billion years old, these are no more than an instant. Between the mid Sixties and the start of the Eighties, following some particularly cool and snowy years, the glaciers in most parts of the world recorded a small advance, which strengthened the hypothesis of an imminent glaciation. At present the alarm generated by the progressive increase in temperatures and the concomitant progressive retreat of the glaciers around the world lead to the fear of a rapid, almost total, melting of all the ice worldwide… The disagreement among the most authoritative scientists, together with the objective difficulty to create valid forecast models, make it difficult to hypothesize what is in store for us in the future. The alarmism of some theories, which at times is misleading, should be abandoned in favour of serious research, giving greater value to the different theories, with data collected on site, also making use of the reconstruction of events of the past, to build models, and also to be used as healthy “lessons”. A particularly warm year  or a winter with particularly abundant snowfall are certainly not sufficient to speak of global heating or arrival of glaciations. What is important, on the contrary, is to monitor our planet and live in the greatest respect of its natural equilibriums.