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First hole forms in Arctic ozone layer -

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First hole forms in Arctic ozone layer

Lexi Metherell reported this story on Monday, October 3, 2011 08:13:00

TONY EASTLEY: Scientists have uncovered the first hole to form in the ozone layer above the Arctic.

It's a sign that chlorofluorocarbons or CFCs are still damaging the stratosphere, even though their
production stopped 15 years ago.

Lexi Metherell reports.

LEXI METHERELL: In the stratosphere above the Antarctic, a hole has developed in the ozone layer
every winter since the 1980s and this year, for the first time on record, one has formed above the
Arctic.

A senior researcher at NASA's Jet Propulsion Laboratory, Gloria Manney has been monitoring the
phenomenon.

GLORIA MANNEY: We started seeing in this past winter in the Arctic in February and March that the
ozone in the stratosphere was decreasing much more rapidly than it typically does in the Arctic.

LEXI METHERELL: Levels of ozone over the polar regions drop every winter, because the intense cold
turns man-made chemical emissions in the stratosphere into a type of chlorine which destroys ozone.

The Arctic isn't as cold as the Antarctic, and it doesn't usually get cold enough there for the
ozone layer to develop a hole.

But Gloria Manney says this northern winter was abnormally cold.

GLORIA MANNEY: Usually in the Arctic in the Northern Hemisphere there is only just a little bit of
ozone loss, because it isn't that cold for that long. This year it was cold for longer than usual
and so the chlorine was in forms that could destroy ozone, and so much more ozone was destroyed
than in previous winters that we've observed.

LEXI METHERELL: The production of ozone-destroying chlorofluorocarbons was phased out by 1996 but a
senior research scientist with the Australian Antarctic Division, Dr Andrew Klekociuk says it will
take decades for CFCs to disappear entirely from the stratosphere.

ANDREW KLEKOCIUK: They take 20 or 30 years to break down and we're still seeing, I guess, the
delayed effects of the controls on those gases.

LEXI METHERELL: The researchers measured an 80 per cent drop in ozone levels over the Arctic,
leading to a hole which grew as big as five times the size of California. That's smaller than this
year's Antarctic hole which has grown to be about three times the size of Australia.

Dr Klekociuk says it's likely the hole will increase harmful UV radiation in the Northern
Hemisphere.

ANDREW KLEKOCIUK: One of the factors about the Arctic of course is that there is a larger
population, much more wildlife, vegetation in the high Arctic than in the Antarctic. Those low
ozone levels combined with sunlight produce more UV potentially at the earth's surface.

We are yet to see the results in from UV measurements in the Arctic but one would expect there to
be elevated ultraviolet levels for that particular winter and early spring period.

LEXI METHERELL: The results of the research led by Gloria Manney have been published in the journal
Nature.

TONY EASTLEY: Lexi Metherell.