Sustainability

The response to climatic variations

Many alpine glaciers have been ‘monitored’  for over a century, and for many of these we have measurements of the front position for many consecutive years.  When it is possible to associate  front variations to climatic data such as, for example, rainfall and temperature, then interesting observations can be made on how each single glacier responds to variations in these two important parameters. First and foremost, each glacier responds in a different and independent way, depending on factors such as its size, so that the same climatic event can determine  the rapid forward thrust of one glacier and a standstill  or limited forward movement in a neighbouring one. In addition to this, all glaciers do not respond at once, but react with a certain inertia, normally a couple of years. A positive balance is usually due to cool summers with snowfall that greatly reduce summer ablation, while winters with little snow, albeit cold, and very hot summers bring about negative balances. However, the hot season events are those that bring about the more significant variations, so that it is not so important how much snow fell in winter  but how much of it was preserved in summer. In a glacier’s balance, therefore, a sweltering summer like that of 2003 or 2004 will play a more significant role than a particularly snowy winter, like that of 2000-2001.