Researchers suspect global warming may be
 the culprit behind the hole in the ozone
 layer
 

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It may be the last time we ever see a hole so bad in the ozone
layer over the South Pole. There is a massive opening as big as the
United States and Canada combined.

"This is how it's grown over the last 20 years. The blue area
expanding ever larger up to now, when the winter down under was
particularly harsh. Temperatures were nearly 200 degrees below zero
in the lower atmosphere. That's a minus 90 centigrade," says NASA
Scientist Rich McPeters.

When temperatures get down to about a minus 90 or so centigrade,
that's trouble.

Researcher Bob Dezafra told us from Antarctica today that global
warming, which heats things up elsewhere, makes the bottom of the
world much colder and may have been the cause.

"The ozone hole started earlier this year and it just went on being
more severe from the very beginning," says Researcher Bob Dezafra.

The swirling red rings in the NASA satellite data indicates higher
levels of ozone and the red area is expected to grow as the last
of ozone depleting chemicals disappear from use. Scientists say
ozone loss should peak next year and the protective shield should
start to thicken over the next decade.

Very good news, especially in the Southern Hemisphere where less
ozone has meant higher levels of harmful UV rays from the sun and
an increased danger of cancer. Still, it will take another half
century to get ozone levels back to where they were in the late
70's. And there's still that wild card, global warming, at play.