- LONDON (Reuters) - The gaping,
man-made hole in the ozone layer over Antarctica has hit record proportions
for this time of year and could get bigger still within the next few days,
a leading scientist said Friday.
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- At just short of 10.81 million square miles, the hole
is a fraction under the absolute record of 11 million, but it has historically
peaked in the second week in September and therefore could theoretically
grow further, British Antarctic Survey (BAS) scientist Jonathan Shanklin
told Reuters.
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- "It was the largest it has ever been during August,
and we are waiting to see what happens over the next few days," Shanklin
told Reuters by telephone from BAS headquarters in Cambridge.
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- The stratospheric ozone layer protects the earth's surface
from damaging ultraviolet rays that can cause skin cancer.
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- In 2002 the hole suddenly shrank, raising hopes it had
turned the corner and was starting to close. But Shanklin said scientists
now believed this was an abnormality due to atmospheric conditions, and
that the 2003 expansion was back to more normal activity.
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- Shanklin said there was no direct link between the hole
and the sharp rise in skin cancers worldwide, which he said was closely
linked to changing lifestyles. However, he said the general thinning of
the ozone layer elsewhere because of chemical depletion was almost certainly
involved in the rise.
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- Shanklin, one of the scientists who first discovered
the ozone hole in 1985, said he and his colleagues were still at a loss
to explain exactly why it had got so big in August.
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- "The ozone hole is continuously in motion. It is
rather like a spinning top," he said.
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- The 1985 discovery forced a radical review and ultimately
a complete change in many industries that were belching ozone-depleting
chemicals into the atmosphere.
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- The consequent drop in output of these chemicals began
to bite in 1994 and is now some 6 percent down on its peak.
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- However, the time lag in the chemicals reaching the upper
atmosphere and attacking the key stratospheric ozone layer has meant that
the benefits of the output reduction has taken several years to feed through.
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- "We don't know if the hole has finally peaked, is
over the top and on the way down or still has a bit further to go,"
Shanklin said.
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- "We are sure that we are pretty near the top, but
we could have to wait another decade to be able to say definitively that
the worst is over and it is starting to recover," he added.
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- Shanklin said it was vital for countries to stick to
the Montreal Treaty curbing the emission of ozone depleting chemicals.
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- But he stressed that until there was similar accord on
greenhouse gases it was impossible to tell what effect there would be on
the atmosphere.
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- Most major polluting nations have signed up to the Kyoto
treaty curbing carbon dioxide emissions. But the United States has refused,
even going so far as to refuse to accept that the gas is a pollutant.
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- "It would be excellent if all countries in the world
pulled together on greenhouse gases," Shanklin said. "The discovery
of the ozone hole proved we can change our atmosphere so easily. It was
a big surprise. There may well be further surprises in store for us."
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