Energy

Ice: is it an inexorable resource?

With only very few exceptions, glaciers all over the world are in a retreating phase, that began at the start of the last century and was interrupted for a short period of time with a small advance in the Alpine area around the Eighties. This endangers not only the existence of the glaciers but also of an important renewable source of energy. Ice and the water deriving from it therefore seem destined to turn into a source that is becoming exhausted and that is not renewed any more as is the case of fossil fuels. In fact the mass of most of the Italian glaciers shows a negative trend. In summer more ice is melted than what is formed during the cold season, hence the mass of the glaciers decreases. Unlike the fossil fuels that are exploited according to the will of man, and that can be planned and programmed to a certain extent, by storing “strategic” reserves if necessary, the amount of water produced from melting glaciers can be used only when it is available. This source of energy depends on meteorological characteristics and in the course of the years, on fluctuations in the climate that are also influenced by man’s activities.
For example, the torrid summer of 2003, that was hot and dry above average, favoured the output of a large amount of melted water that was not completely exploited for the production of energy. In fact the artificial reservoir that has been built, contains only a limited volume of water and the technical characteristics of the plants are designed to produce a fixed maximum quantity of energy even though the available resource is present in excess. The water resources coming from the glaciers are therefore difficult to manage. The only certainty they offer is the great availability during the summer months. For how many more years will it still be possible to exploit this resource? The state of the glaciers in Italy In Italy there are approximately 800 glaciers, that cover a surface of approximately 550 km2, equal to 1/5 of the overall surface covered by the glaciers of the Alpine mountain range. According to data of the Comitato Glaciologico Italiano (the Italian Glacier Committee) in 1999, 89% of the Italian glaciers was retreating, this condition was more marked for the glaciers in Lombardy, less in the Triveneto area and in the Piedmont-Valle d’Aosta regions. The retreating trend began after 1860, the year that is considered as the end of the last cold period, the so-called Little Ice Age. Beginning from the mid Nineteenth Century, 40% of the surface of the Italian glaciers has been lost, while the snow-line has risen 100 m. In the past 20 years Italian glaciers have lost 10 to 20% of their volume of ice. These data are troubling : if the present trend does not meet with any variations, most of the Italian glaciers will disappear in a few decades, and with them also an important source of energy.