OZONE HOLE NOW THE SIZE OF NORTH AMERICA

[Anonymous]

Hole in Ozone Layer Now the Size of North America

Damaging Chemicals Persist in
Atmosphere, Despite Ban on Manufacture
(Oct. 06) – The so-called “hole” in the earth’s
protective ozone layer is at a new record — 10.6 million square miles of sky
around the South Pole — even though most nations agreed back in 1987 to phase
out the chemicals that cause it.

The number was reported today by U.S. government
scientists, who said protecting the ozone layer was still clearly the right
thing to do, but that it’s taking longer than originally expected for the ozone
layer to heal. A 10.6 million mile gap in it is about the size of North
America.

“It’s going to be like this for the next
decade,” said Paul A. Newman, a senior research scientist at NASA’s
Goddard Space Flight Center in Greenbelt, Md. “And then it will start
tipping over, and decreasing, and be gone around 2070.”

That’s a delay of 15-20 years. Early computer models had
shown the ozone layer would be back to normal around 2050.

Ozone Layer Vital to Life

Ozone molecules, which form in the upper atmosphere and
waft around approximately 12-20 miles above the Earth’s surface, protect us
from the harmful ultraviolet rays of the Sun.

If ozone is destroyed, scientists say there would be
multiple effects — increased rates of skin cancer and cataracts; and death of
tiny plankton in the oceans, which form the base of the world’s food chain in
many cases.

Scientists gave the world a shock in the 1970s and 1980s.
They realized that commonly-used chemicals — the CFCs and halons used in
everything from air conditioners to fire extinguishers to spray cans — were
escaping into the stratosphere. Through complex reactions, they were eating
away at the amount of ozone there.

What was more, they found that in the early spring in
the southern hemisphere — September and October — a giant ozone
“hole” formed in the swirling air currents over Antarctica, and often
spread over South America, Australia and New Zealand.

New Measurements From Orbit

But new readings, provided by the Ozone Measuring Instrument
aboard NASA’s earth-observing Aura satellite, show what scientists suspected —
that even if CFCs are no longer made, molecules of the gases survive in the
upper atmosphere for 40 to 100 years.

So the ozone hole has appeared again, bigger than ever.

“These numbers mean the ozone is virtually gone in
this layer of the atmosphere,” said David Hofmann, director of the Global
Monitoring Division at the NOAA Earth System Research Laboratory, in a
statement. “The depleted layer has an unusual vertical extent this year,
so it appears that the 2006 ozone hole will go down as a record-setter.”

Does that mean the Montreal treaty has been a failure?
Hardly, say the scientists who have worked on the issue — if nothing had been
done, the ozone loss would be much greater.

But they say people need to recognize how complex the
chemistry of the atmosphere is, and be patient.

“It’s very clear what happened over Antarctica,
and why it happened,” said NASA’s Newman. “There’s absolutely no
question at all about the causes of the ozone hole.”

[Author]

October 20, 2006 at 12:02 PM