Snow and Skiing
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Snow cover in temperate mountain regions, being relatively
thin and often close to melting point, is very sensitive to warming.
Skiing depends critically on the quality, the extent, the depth
and the duration of snow cover. Global warming is likely to reduce
all of these, with harsh repercussions for the skiing industry
in many countries. This could cost US$ 1.7 billion a year in the
United States. In Australia the skiing business could disappear
altogether.
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The length of the skiing season is sensitive to small changes
in climate. In the European Alps, a warming of 2oC
could delay the first snowfall and advance the onset of melting
by two to three weeks, according to some predictions. Seasons
with less snow, particularly during the crucial Christmas to New
Year holiday, spell economic disaster to many mountain communities.
In the warm winter of 1989/90 a number of lowaltitude Swiss
tourist destinations reported an 80 per cent fall in turnover.
The skiing industry generally requires at least 2530 cm
of snow cover for a minimum of 100 days to be profitable. Areas
above about 1,200 metres in the Swiss Alps have mostly met these
conditions in recent years. A projected warming of 3oC
would raise the breakeven altitude to around 1,500 metres.
The consequences for the local economies around resorts between
1,200 and 1,500 metres could be critical, where remote rural communities
may have to revert to agriculture once again.
The CROCUS computer model developed by the Centre d'Etude de la
Neige in Grenoble, France, suggests that, at an altitude of 1500
metres in the French Alps, a rise of 1.8oC would reduce
the period of snow cover by 20 per cent in the north, and up to
40 per cent in the south, with the greatest reduction in the Alpes
Maritimes. The decrease in depth of snow, however, would be greatest
in the northern French Alps - over 50 cm around Mont Blanc, for
example. The reduction in the period of snow cover would be less
severe at higher altitude, about 10 per cent at 3,000 metres,
but melting will start about three weeks earlier.
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Satellite imagery shows that lowlands around the Alps in Germany,
Switzerland, Austria and the plains of the River Po received three
to four weeks less snow cover a year during the early 1990s than
in previous decades. Furthermore, the seasonal timing of snow
fall has changed, with an increase during October and November,
but less from December to February because of stable high pressure
weather over Europe. Snow falls have then resumed in March and
April, and even as late as May.
Artificial snow is sprayed on the pistes in some resorts, but
its requirement for water and energy makes it an undesirable alternative.
More than 60 Swiss resorts, and many more in the United States,
have installed snow cannons, which require water to be pumped
up from lakes and rivers. The fake snow is more compact than normal
snow, and damages the underlying vegetation.
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