Water

What about the future?

Glaciers are sensitive indicators of climatic variations, in particular variations in temperature and precipitation, and through studies of the frontal variations and mass balance, it is possible to follow their behaviour during the course of the years. Generally, starting from the mid Eighties, after a short advance stage, most of the glaciers all over the world are in a retreat stage,   even though of course there are some exceptions. For example in Norway the Nigardsbreen Glacier, one of the outlet glaciers of the great  Jostedalsbreen  Glacier, the largest in Europe, excluding Iceland, which is monitored since 1962,  in 40 years of observations,  has shown 26 years of positive balance  and has moved forward 260 m between 1988 and 2000, therefore showing a great difference with respect to Alpine glaciers. In fact these differences make us understand how processes connecting the behaviour of glaciers and climatic variations are not well known and many years of field-research are still necessary in order to make it possible to formulate hypotheses about the future for us, together with glaciers, on our planet.
Also with regard to the large ice-sheets, data are still not complete enough in order to obtain the general picture. It can be observed that the detachment of icebergs, even the very large ones, is a common event, and also the size of the ice shelves varies continually, expanding and retreating according to a trend that  still has not been determined. In May 2002, the Ross Ice Shelf “lost” an iceberg that was a little less than 200 km, and in the following months it lost at least three other giants, varying between 80 and 50 km, which detached from the same area : after these events  the Ross Ice Shelf returned to the size that was recorded in 1911 by the explorer Robert Scott. This would seem to indicate an expansion compared to the first years of the last century. Since 1979, however, it seems that the fragmentation of the Antarctic ice shelves  has intensified; but if observations are limited only to  the icebergs, it is not possible to state if the ice in Antarctica is decreasing. Every year the Antarctic ice shelves lose approximately 1,450 – 2,000 km3  of ice, but this datum is not sufficient : in order to make more precise affirmations it is necessary to verify if the quantity of ice lost in the form of icebergs is greater or less than the quantity of new ice that  has formed subsequent to the annual snowfall. Only with these data available, for a certain number of years, is it possible to determine a balance, and therefore to attempt an estimate about the future of  Antarctic ice. What is certain, is that compared to the Forties, a 2.5°C increase has been recorded in the average annual temperature , which should accelerate ice melting; however, beside this, in some areas in Antarctica, since a few years, there has been an increase in snowfall, which should feed the ice sheet and its glaciers : which of these two trends will prevail in the future is difficult to tell, however it is evident that all depends on a fragile equilibrium, in which the factors mentioned above are only two of the many variables in the complex game of the Earth’s climate. All things considered, many years of studies and constant observations are still required in order to understand how the climate of our planet works, and consequently present forecast models for the near future : we understand how  on-site research is fundamentally important  in order to support scientific theories and forecast models, with objective data collected “in nature” .