On Mar 27, 10:09*am, "Ms. 2"
wrote:
New theory blames cosmic rays for helping CFCs deplete ozone
Fellow scientists say Waterloo professor's hypothesis needs more study
Last Updated: Thursday, March 26, 2009 | 8:02 PM ET

By Emily Chung, CBC News

The hole in the Earth's protective ozone layer above Antarctica will be very
big this year - and it will be big again in 2020 - contrary to previous
predictions, argues a Canadian researcher.

Qing-Bin Lu, a professor of physics and astronomy at the University of
Waterloo, says his research suggests the long-held theory about how
ultraviolet light combines with man-made chemicals to destroy the Earth's
ozone layer is incorrect.

snip

That horse is alreday dead. Continue to flog it if it amuses you.
The 'danger' to the ozone hole was over-rated by about ten-fold.

To save you a subscription fee, the key prtion is as follows:

"As the world marks 20 years since the introduction of the Montreal
Protocol to protect the ozone layer, Nature has learned of
experimental data that threaten to shatter established theories of
ozone chemistry. If the data are right, scientists will have to
rethink their understanding of how ozone holes are formed and how that
relates to climate change.

Long-lived chloride compounds from anthropogenic emissions of
chlorofluorocarbons (CFCs) are the main cause of worrying seasonal
ozone losses in both hemispheres. In 1985, researchers discovered a
hole in the ozone layer above the Antarctic, after atmospheric
chloride levels built up. The Montreal Protocol, agreed in 1987 and
ratified two years later, stopped the production and consumption of
most ozone-destroying chemicals. But many will linger on in the
atmosphere for decades to come. How and on what timescales they will
break down depend on the molecules' ultraviolet absorption spectrum
(the wavelength of light a molecule can absorb), as the energy for the
process comes from sunlight. Molecules break down and react at
different speeds according to the wavelength available and the
temperature, both of which are factored into the protocol.

So Markus Rex, an atmosphere scientist at the Alfred Wegener Institute
of Polar and Marine Research in Potsdam, Germany, did a double-take
when he saw new data for the break-down rate of a crucial molecule,
dichlorine peroxide (Cl2O2). The rate of photolysis (light-activated
splitting) of this molecule reported by chemists at NASA's Jet
Propulsion Laboratory in Pasadena, California1, was extremely low in
the wavelengths available in the stratosphere - almost an order of
magnitude lower than the currently accepted rate.

"This must have far-reaching consequences," Rex says. "If the
measurements are correct we can basically no longer say we understand
how ozone holes come into being." What effect the results have on
projections of the speed or extent of ozone depletion remains unclear.

"The rapid photolysis of Cl2O2 is a key reaction in the chemical model
of ozone destruction developed 20 years ago2 (see graphic). If the
rate is substantially lower than previously thought, then it would not
be possible to create enough aggressive chlorine radicals to explain
the observed ozone losses at high latitudes, says Rex. The extent of
the discrepancy became apparent only when he incorporated the new
photolysis rate into a chemical model of ozone depletion. The result
was a shock: at least 60% of ozone destruction at the poles seems to
be due to an unknown mechanism, Rex told a meeting of stratosphere
researchers in Bremen, Germany, last week."

http://www.nature.com/news/2007/0709...l/449382a.html

The hyperbolic appellation "ozone hole" turn out to apply to a
seasonal reduction of the stratospheric ozone concentration that is
restricted to the polar regions. It restores itself annually. Of
course, the chlorides that everybody has always worried about are
still present even as the ozone concentration performs its annual
INCREASE.

Tom Davidson
Richmond, VA