SOUTH AMERICA: Glaciers - Going, Going…Gone?
By Marcela
Valente
BUENOS AIRES (IPS) - South America is
perhaps most often associated with the
Amazon jungle, the world's largest tropical
rainforest. But along its western edge, from
Ecuador to southern Chile and Argentina, it
also harbours huge glaciers which are
rapidly melting due to global warming.
The 18,000-year-old Chacaltaya glacier in
the Bolivian Andes disappeared in August.
Experts had forecast that it would survive
until 2015, but it melted sooner than
predicted, and what used to be famed as the
world's highest ski run, 5,300 metres above
sea level, is now a boulder-strewn slope
with a few patches of ice near the top.
In Ecuador, an avalanche at the base of the
Cayambe glacier killed three tourists and a
mountain guide this year. And in May, an
avalanche caused serious damage in the area
of Pampa Linda, at the base of Monte
Tronador (Thundering Mountain) in southern
Argentina, when a glacier collapsed.
These isolated avalanches confirm the trend
towards the collapse of the Andean glaciers,
experts say.
"Glaciers in Ecuador, Peru and Bolivia have
their days numbered," Juan Carlos Villalonga,
head of the Argentine chapter of the global
environmental watchdog Greenpeace, told IPS.
The ice sheets in Cuyo, in western
Argentina, and the even larger ice sheets of
Patagonia, shared between Argentina and
Chile in the southwest of the continent, are
also shrinking.
According to Greenpeace, the melting of the
glaciers must be a cause for concern among
the world leaders who will be meeting in
Copenhagen in December for the 15th United
Nations Climate Change Conference, and
greater commitment is needed to curb the
greenhouse gas emissions that cause global
warming.
In an interview with IPS, glaciologist
Ricardo Villalba of the Argentine Institute
of Snow Research, Glaciology and
Environmental Sciences (IANIGLA) said that
the retreat of the glaciers' enormous ice
masses "is a global process which began in
1850 and has accelerated since 1970."
However, this process "is not an even one,"
he said. "In Ecuador or Bolivia, where the
glaciers are smaller, they tend to collapse
more quickly," whereas in Argentina, some
are shrinking at an alarming rate while
others are surviving, depending on
temperature and rainfall.
On average, however, glaciers in Patagonia
have shrunk by between 10 and 20 percent in
the last 20 years. "If this trend persists,
the ice will all disappear within 60 or 70
years," he said.
In a study updated in August, "Cambio
Climático: futuro negro para los glaciares"
(Climate Change: A Black Future for
Glaciers), Greenpeace Argentina warns that
the melting of glaciers in South America is
accelerating. The report contains a reminder
that the Intergovernmental Panel on Climate
Change (IPCC) predicted this trend in 2007.
According to the IPCC, the average global
temperature has risen by 0.74 degrees over
the last 100 years, and the area permanently
covered by ice and snow has shrunk. It also
indicates that 11 out of the last 12 years
have been the hottest since 1850, and global
temperature is forecast to continue to rise
this century.
"One of the effects climate change is
expected to have is a massive loss of
permanent ice cover on the earth's surface,
from the polar ice caps as well as from
different bodies of continental ice," the
Greenpeace report says. This will have
severe consequences, it stresses.
In first place, sea levels will rise,
causing forced migration and the loss of
coastal infrastructure. The proportion of
reflecting ice on the earth's surface will
also shrink, increasing the amount of solar
radiation absorbed by the earth and
exacerbating global warming.
But above all, the melting of the glaciers
means the loss of vast reserves of fresh
water for human consumption, and for the
rivers that provide hydroelectric power.
These losses will particularly affect the
Andes highlands in South America.
"South America has a surprising variety of
glaciers along the length of the Andes
mountain range, and the largest of them are
found in Patagonia," says the Greenpeace
study. In Ecuador, "their disappearance is
imminent," and the significance of this is
underlined by the fact that 50 percent of
the water used by the population of Quito is
glacier meltwater.
The report confirms the findings of a 2008
research study by the World Bank, titled
"Impact of Climate Change in Latin America",
which points out that 70 percent of the
world's tropical glaciers are in the Andes
mountains, in Ecuador, Peru and Bolivia.
In Peru alone, where millions of people
depend on meltwater for their daily supply,
22 percent of the surface area of glaciers
has been lost in little over 30 years. The
Quelcaya ice cap has lost 20 percent of its
volume since 1963, the study says. "It has
retreated faster in the last century than in
the previous 500 years," according to
Greenpeace.
"In the 1990s, the rate of retreat has risen
to 30 metres a year," Greenpeace said,
referring to this glacier that supplies Lima
with its water.
In Argentina, the immense ice sheets in Cuyo
"are in a highly critical situation," the
report notes. Water is scarce in this part
of the country: in the western province of
Mendoza, for instance, only three percent of
the land is oasis; the rest is desert and
depends heavily on icemelt for water.
In Patagonia, some 20,000 square kilometres
of glaciers are shared between Argentina and
Chile. The Southern Ice Field in both
countries spreads over 13,000 square
kilometres, the Northern Ice Field in Chile
covers 4,200 square kilometres, and the
Darwin mountain range glaciers, also shared
by the two countries, cover 2,500 square
kilometres.
"Many of the largest glaciers in these ice
fields have thinned alarmingly and retreated
several kilometres," except for two of them,
the Perito Moreno glacier in Argentina and
the Pío XI glacier in Chile, which are
stable or even advancing, Greenpeace says.
In Villalba's view, the fragile glacier
ecosystem depends on the balance between the
amount of snowfall and the temperature,
which must be low, otherwise the glaciers
collapse. He said that the recent retreat of
the glaciers is associated mainly with the
rise in temperature.
"The Upsala glacier, for instance, is
retreating amazingly fast," Villalba said.
The glacier flows into Lago Argentino, in
the southern province of Santa Cruz, and its
contact with the lake accelerates its
erosion. The same is true for the Viedma
glacier, in the same province.
"As long as greenhouse gases continue to be
released into the atmosphere, the ice will
melt at an increasing rate, which is why we
are calling for a reduction in the use of
fossil fuels and the pursuit of alternative
energies," Villalba said.
|
|
|
|
|
| |
|
|
|
|
|
