/October 13, 2005 by Inter Press Service <http://www.ipsnews.net>
<http://www.ipsnews.net> /
* Chilling Effects of Climate Change in the Antarctic *
*
by Gustavo González*
http://www.commondreams.org/headlines05/1013-03.htm
SANTIAGO - Climate change, which the scientific community links to the
increased intensity of tropical storms and other extreme weather
phenomena, is also making itself felt in Antarctica, where the "hole" in
the ozone layer continues to grow and the increasing break-up of the ice
shelves could have played a role in the recent deaths of Argentine and
Chilean scientists and members of the military.
This undated photo shows polar stratospheric clouds lit from below near
Kiruna, in Sweden. Polar stratospheric clouds, long known to play an
important role in Antarctic ozone destruction, are occurring with
increasing frequency in the Arctic. As high altitude clouds that form
only at very low temperatures, they act as 'breeding grounds' for
ozone-destroying molecules. (HO/NASA/Lamont Poole GN/jp/Reuters)
"The hole in the ozone layer expanded this year, and the quantity of
ozone destroyed within that area increased as well," Bedrich Magas, a
researcher with the University of Magallanes, told IPS from the city of
Punta Arenas. Magas carries out daily measurements of ultraviolet
radiation in the port city of 120,000, located at the southern tip of
Chile.
According to the Argentine Antarctic Institute, in September - the start
of the southern hemisphere spring - the hole in the ozone layer reached
28 million square kilometres, representing an eight percent increase
from 2004. In addition, the ozone value dropped from 95 to 87 Dobson
Units (a measure of the "thickness" of the ozone layer, with 220 units
considered the acceptable lower limit).
In satellite images, the hole appears as a fluctuating oval-shaped area
that in the most critical period - which peaks in September and October
- stretches from Antarctica to the southern part of South America,
affecting cities in southern Argentina and Chile like Punta Arenas,
1,000 km north of the Antarctic's King George Island and 2,300 km south
of Santiago.
The ozone layer protects the earth from the harmful effects of
ultraviolet radiation, which include skin cancer and cataracts in humans
and threats to flora and fauna.
Claudio Casiccia, a physicist who heads the Ozone Laboratory at the
University of Magallanes, told IPS that in early October, the hole
shrank to 21 million square kilometres, from 24 million square
kilometres in August and 28 million square kilometres in September.
Nevertheless, the ozone value has remained below 100 Dobson Units.
"The southern portion of South America, Patagonia and the Magallanes
region, are under the influence of the Antarctic ozone hole for a short
period in springtime, with varying thickness and intensity. This year,
we had an event (in Punta Arenas), but there was no major increase in
ultraviolet radiation, because the angle of the sun is still steep and
it is quite cloudy," said the scientist.
The thinning of the ozone layer is blamed on chemical emissions like
halons, which are used in fire extinguishers, CFCs
(chlorofluorocarbons), used in refrigerators, air conditioners and
aerosols, and methyl bromide, used as a pesticide and in building
fumigations.
The Montreal Protocol, signed in 1987, set global targets for phasing
out these chemicals, which "according to estimates by scientists will
allow the ozone layer to recover by the middle of this century," Ana
Isabel Zúñiga, head of the governmental National Environment
Commission's Ozone Programme in Chile, told IPS.
But the scientific community itself has warned that the greenhouse
effect, caused by carbon dioxide (CO2) and other emissions from the
burning of fossil fuels blamed for global warming, is also having an
impact on the thinning of the ozone layer.
The Kyoto Protocol, aimed at cutting emissions of greenhouse gases -
which has not been signed by the United States, the largest single
source of these gases - should thus act along with the Montreal Protocol
to protect the ozone layer, while it curbs other phenomena attributed to
global warming.
Attention has been focused lately on devastating hurricanes like Katrina
and Stan, because studies have shown that warmer oceans and rising sea
levels are producing stronger tropical storms, said Vicki Arroyo,
director of policy analysis for the Virginia-based Pew Centre on Global
Climate Change.
Another U.S. scientist, Peter Frumhoff with the Global Environment
Programme of the Union of Concerned Scientists, told IPS in late
September that "The recent science has clearly linked higher storm
intensity to climate change."
The phenomenon of climate change was also blamed for the drought, high
temperatures and flooding seen in Europe since 2002.
Casiccia said that while the link between global warming and extreme
weather events is still being studied, "it has been accepted that there
is an important relationship, in need of further study, between the
weakening of the ozone layer and global climate change."
Paola Vasconi, coordinator of the Santiago-based Terram Foundation's
environment programme, told IPS that the increase in ultraviolet
radiation also drives up temperatures.
"One thing is probably certain: if the climate does not stabilise, the
hole in the ozone layer will never close," said Magas, who pointed out
that the United States emits "the shocking equivalent of 25 tons of CO2
per capita every year, compared to 3.7 tons for Chile and a global
average of three tons per capita."
The link between global warming and the thinning of the ozone layer was
demonstrated in 1987 by international measurements taken in the
Magallanes region, the scientist pointed out.
"The incredible thing is that after that, efforts were not undertaken to
curb emissions of greenhouse gases, which are today, now that CFC
emissions have been curtailed, the main cause of the destruction of
ozone worldwide," said Magas.
"Although it sounds terrible, the hurricanes are welcome, if that's what
it takes to change the mentality of the big, irresponsible polluters,"
he added.
U.S. "President (George W.) Bush issued a call to 'drive less' and
announced a federal programme aimed at cutting fuel consumption -
accompanied, of course, by deregulation policies on the environment
allowing for increased exploration and drilling for oil in protected
wilderness areas," said Magas.
On Sept. 16, International Day for the Preservation of the Ozone Layer,
United Nations Secretary-General Kofi Annan underscored the efforts made
by the international community to curb the use of ozone-depleting
substances.
The next day, two Argentine men lost their lives in Antarctica -
biologist Augusto Thibaud and naval officer Teófilo González - when
their snowmobile plunged into a deep hidden crevasse.
And on Sep. 28, Captain Enrique Encina and non-commissioned officers
Fernando Burboa and Jorge Basualto, members of the Chilean army, died
when their snow-cat fell into a 40-metre crevasse in Antarctica.
Magas pointed out that although there have always been crevasses on that
continent, making travel dangerous, the ice shelves are increasingly
breaking up due to the higher temperatures associated with global warming.
With a surface area of more than 14 million square kilometres,
Antarctica is the fourth-largest continent. A full 95 percent of the
territory is ice, and the continent accounts for 70 percent of the
world's fresh water reserves.
|