U.S. Water News Online
SION, Switzerland -- Greyed by the heat and riven with deep
cracks, Switzerland's mighty Alpine glaciers are shrinking at a
record rate in this summer's sizzling sun.
Scientists may disagree over some of the causes of the heat wave
which has sent temperatures soaring in Europe and about how much
people are contributing to global warming, but the effects high in
the Alpine valleys are visible. The Alpine glaciers, source of some
of Europe's biggest rivers, have been in retreat for more than a
century, but the loss of ice has speeded this year as temperatures
"The rate of ice melt is some three or four times the usual
amount," said Charly Wuilloud, head of the department of natural
dangers at the Valais state forestry department.
Some 9,000 feet above the Rhone valley in southern Switzerland, at
the junction of the Ferpecles and Mount Mine glaciers, the
temperature is an unusually warm 59-68 degrees Fahrenheit. Sporting
sunglasses and a short-sleeved shirt more typical of beach ware,
Wuilloud pointed to the rush of melt water streaming from the ice
wall of the Ferpecles glacier.
The so-called equilibrium line, the point at which any fresh snow
or rain falling will turn to ice and not melt or run off, is some
984-1,312 feet higher up the mountain this year than usual this
summer, he added.
At one time, the four-miles-long Ferpecles and Mount Mine, some
six miles in extension, joined to form a forked tongue of ice
stretching down into the valley.
Lines gouged into the mountain side tens of yards above the valley
floor show the height to which the ice once reached.
Scientists say Europe's glaciers have been shrinking since the
1850s, initially as a result of a natural warming of the earth
following a 250 year cold snap.
But the process has picked up pace over recent decades --
particularly since the 1970s -- under the impact of global warming
fuelled -- many scientists believe -- by high emissions of greenhouse
According to the United Nations' International Panel for Climate
Change (IPCC), the average temperature of the earth rose 0.5 Celsius
during the 20th century and could rise several times that rate over
the next 100 years.
Back in the 1990s, even before this year's blistering summer,
geologists at the Zurich-based World Glacier Monitoring Service
(WGMS) forecast that the glaciers would shrink to just 10 percent of
their 1850 size by the end of the 21st century.
By 1970, they had already declined to around half and were seen
losing a further 50 percent by 2025, according to geography professor
Wilfried Haeberli of the University of Zurich.
The latest estimates are that 25-30 percent has already gone. "It
looks like our prediction was a little bit optimistic. It is going
faster than we thought," he said.
Glaciers have long been seen as one of the most sensitive
detectors of climate change, with the impact showing up first in the
thickness of the ice rather than its length, which can take years to
This year a number of factors have combined to intensify the rate
of melt, including a freak weather event last November when a cloud
of dust was blown north from the Sahara desert.
As glacier surface ice melted with the coming of spring, the dust
was exposed again, helping give the ice a greyish appearance that
reduced reflection and increased the amount of sunlight absorbed --
hence the melt.
Although studies for this year are not yet finished, Haeberli said
the Alpine glaciers could have slimmed down some six feet or more --
an exceptional loss of thickness.
This would be 10 times the average annual melt over the length of
the 20th century and some four times that of the two decades between
1980-2000 when global warming was already making its presence felt.
"This looks like a record year," he said. "There is no doubt that
it has been exceptional."
RISK TO RIVERS
For those living in glacial valleys, the thinning of the glaciers
when combined with heavy rain brings the danger of flash floods like
the one which killed 13 people in the Gondo valley of Switzerland in
Melt water can form lakes either on the surface of the glacier or
below it which can suddenly be released with devastating
consequences. Wuilloud said that the Valais authorities were already
warning people not to camp near glacier-fed streams or other areas
vulnerable to flooding. Over the long term, the shrinkage in the size
of the glaciers could have a dramatic impact on water supply.
In summer some 50 percent of the water carried by the Rhone from
its source in the Alps through Lake Geneva to the Mediterranean comes
from ice melt. "Glaciers hold water back in winter and let it go in
summer," Haeberli said. "If they go, so will the water."
Return to the
U.S. Water News Archives page
Return to the U.S. Water
Use a comma to separate e-mail addresses:
Hi, I thought you might like to read this article.