http://www.commondreams.org/headlines02/0925-05.htm
Published on Wednesday,
September 25, 2002 in the Los Angeles Times
Global Warming
Glacial Melting Takes Human Toll
by Usha Lee McFarling
[ See
photograph of aftermath of giant piece of glacier that roared
down a gorge popular with hikers... ]
CAPTION:
"A general view of the path of ice, rocks and other debris
that
raced down a mountain in the Russian republic of North Ossetia,
about 1,200 km (750 miles) south of Moscow, Monday,
Sept. 23, 2002. More than 100 people remained missing Monday
following a devastating avalanche in southern Russia as rescuers
renewed their efforts to find survivors after a giant chunk of
glacier
roared down a gorge popular with hikers. (AP Photo/Ivan Sekretarev)"
The entombment of a Russian village under 3 million tons of ice
and mud from a collapsing glacier is a sign of the gradual yet
vast climatic changes sweeping the world's mountainous regions,
scientists say.
The disaster on the
slopes of the Caucasus Mountains on Friday
left more than 100 people missing and at least nine dead.
Researchers maintain that the avalanche is part of a subtle
chain of events that has transformed once-frozen mountains and
is altering the course of nearby human settlements in unexpected,
and sometimes disastrous, ways.
The changes often have been difficult to perceive, because
they have taken place over such a long period of time and
because their effects are not always clear--some regions
have become colder, even as others warm.
But scientists say
there is little question that a world of
ice is in flux.
Glacier National Park
in Montana has lost more than 100 glaciers
during the last century, vanished into a slow drip of runoff.
In Venezuela, only two glaciers remain where there were six
30 years ago. In Tanzania's Mt. Kilimanjaro, about 75% of the
glacier has retreated, leaving some to suggest that Ernest
Hemingway's famous "Snows of Kilimanjaro" will exist
only in
literature in about a decade.
The United Nations
Environmental Program completed a Himalayan
glacier survey this summer that found dozens of mountain lakes
in Nepal and Bhutan so swollen from melting glaciers that they
could burst in the next few years, inundating villages throughout
the region.
"I don't think
we fully understand the full extent of these impacts,
but I'm convinced they're happening," said Tony Prato, an
ecological
economist at the University of Missouri. "People will adapt
if
they can, but it will be painful, and sometimes it will cost lives."
The human toll has
been largely overlooked in the debate over
global warming. Much of the attention paid to climate change
has focused on the Arctic and Antarctic, regions vulnerable to
temperature change but sparsely populated.
The Russian disaster
and growing changes throughout the world's
mountainous regions show that the warming of the world's climate
is beginning to affect areas much closer to home--temperate
regions that are often densely populated. The last decade has
brought some of the most rapid change of the century--seven of
the last 10 years were the warmest on record.
"We have to start
looking at the human dimension," said Alton C.
Byers, a mountain geographer who studies human effects on the
Himalayas and Andes. "There are many unanticipated hardships
for the future."
Glacial avalanches
are not the only worries. Other dangers
include sudden glacial outburst floods that can release vast
amounts of water in seconds. Drought and agricultural crises
also are expected to follow the fading of mid-altitude glaciers.
Although little known,
the changing face of the world's mountain
regions is of growing interest to scientists and land planners.
"We think of mountains
as being pristine and unimpacted by global
change, yet increasingly they are," said Lisa Graumlich,
a climate
expert who directs the Big Sky Institute at Montana State University.
The collapse of the
Maili glacier on the northern edge of the
Caucasus Mountains ripped out trees and tossed massive trucks
as if they were toys. It left a 20-mile path of rocky debris,
blackened ice and devastation.
A full scientific assessment
of what caused the disaster will
take weeks or months, but Russian officials said this week that
the collapse of the glacier seemed at least partly linked to
climate change. It is a tricky issue because the collapse of
glaciers can depend on a variety of near-term factors, including
temperature, rain, humidity, slope and even the reflectivity
of the glacial ice.
But during the course
of a century, scientists say, glaciers
in a wide range of locations around the world have undergone
an enormous change in dynamics brought about by the human use
of "greenhouse" gases, such as carbon dioxide, and the
decades-long swings in ocean and atmospheric patterns that
can greatly affect weather.
A 1998 study by University
of Zurich researchers found that
glaciers of the European Alps have lost about 30% to 40% of
their surface area and about half their volume since 1850.
Glaciers in the New Zealand's Southern Alps have lost 25% of
their surface area during the last century, according to
another study.
U.S. experts said the
Maili glacier incident followed the
pattern of glacier collapse in other areas affected by rising
temperatures.
"Glaciers tend
to [collapse] like that when they're receding,
and glaciers are receding all over the world," said Dan Fagre,
an ecologist and expert on the ramifications of glacier loss
at Glacier National Park in Montana.
The breaking off of
huge chunks from a glacier is the sometimes
spectacular result of a glacier that is gradually retreating
back into the mountains. Glaciers grow only when the amount
of snow they receive is greater than what they lose by melting.
When there is less snowfall, higher temperatures or both,
the "snouts" of glaciers retreat. Some of the ice breaks
off
in deadly chunks; some of it drips away as meltwater.
That seemingly gentle
meltwater can be deadly as well. Such
water often pools in the recess left by the receding glacier
and piles up behind a weak natural dam of sediment and stone.
Once there is enough water pressure behind the dam, it can
suddenly burst in what is known as a glacial lake outburst
flood, unleashing a torrent of water into villages below.
"We know it's
going to go shooting down the flood plain,
and in a mountainous area, that's where the people live,"
said Graumlich of Montana State University.
The Dig Tsho glacial
outburst in Nepal in 1985 destroyed a
hydroelectric plant, wiped out 14 bridges and drowned dozens
of villagers.
The danger is so obvious,
Graumlich said, that some Himalayan
villages have installed primitive warning systems--basically
a system of horns--in attempts to save lives during the next
flood.
"We're just watching
[glacial lakes] form in the Himalayas
and Peru," said Byers, director of research and education
for the West Virginia-based Mountain Institute. "All you
have to do is release that dam and you'll lose vast amounts
of water in seconds."
Huascaran National
Park in Peru has attempted to monitor and
drain the lakes since they started to form in the 1950s,
he said. But the pace of warming is making such work nearly
impossible.
"One of the fears
with warming is they'll be forming so fast,
no one will be able to keep a handle on it," he said, "especially
in countries that have no resources or glaciologists."
Civilizations have
long settled mountain valleys because of
the continuous water supply that flows from the snowpack and
glaciers and because of the rich soil that forms in such
floodplains.
"The notion that
agriculture co-evolved with glaciers is not
surprising," Graumlich said. Mountains also supply 50% of
the
fresh water that is consumed and furnish hydropower, said
Prato of the University of Missouri.
As glacial melting
proceeds, some farmers are enjoying the
unexpected benefit of plenty of water. Farmers around
Mt. Kilimanjaro have found the water supply so bountiful
that they can grow far more than they need to survive.
They are even growing foreign, water-thirsty crops such
as tulips for export to Europe, Graumlich said.
But scientists point
out that eventually the bounty of
water will shrink as the ice disappears.
"More water now
means more agriculture," Graumlich said.
"But what will they do when there is much less water later
on?"
Copyright 2002 Los
Angeles Times
###
--------------------
[ Picture
in original article... ]
A general view of the
path of ice, rocks and other debris
that raced down a mountain in the Russian republic of
North Ossetia, about 1,200 km (750 miles) south of Moscow,
Monday, Sept. 23, 2002. More than 100 people remained
missing Monday following a devastating avalanche in
southern Russia as rescuers renewed their efforts to
find survivors after a giant chunk of glacier roared
down a gorge popular with hikers. (AP Photo/Ivan Sekretarev)
--------------------
