Return to the ground floor of this tower
Return to the Main Courtyard
Return to Fort Freedom's home page
]]]]]]]]]] OZONE CHICKEN LITTLES ARE AT IT AGAIN [[[[[[[[[[
By Robert W. Pease (3/26/1989)
From The Wall Street Journal, 23 March 1989, p. A24:3
[Kindly uploaded by Freeman 10602PANC]
(Mr. Pease is professor emeritus of physical climatology at the
University of California, Riverside.)
The news earlier this month that several European countries
and the U.S. have agreed to phase out the use of chloro-
fluorocarbons by the year 2000 brings before us yet again the
questionable theory that CFCs cause depletion of the ozone layer.
Atmospheric chemist F. Sherwood Rowland [1], of the University
of California, Irvine, formulated the theory in the early 1970s.
His speculations, quoted widely in reports about this month's
international conference hosted by Margaret Thatcher in London,
have gained so much momentum over the years that they have now
become the basis for decisions that would deprive us of the only
inexpensive and effective refrigerants we have for refrigeration
and air conditioning. This is not because of scientific proof,
but the result of the constant reiteration of disaster scenarios
that range from skin cancer to DNA damage.
Pronouncements in the past few weeks give the impression that
all atmospheric scientists are believers, which is far from true.
Many of us are still skeptical because of incompatibilities
between the theory and what we know about the ozone layer:
* The Rowland theory ignores the equilibrium nature of ozone
in the layer. The ozone molecules are constantly being created
and destroyed -- both quite naturally -- by the very short
wavelengths of ultraviolet light from the sun. The amount of
ozone in the layer depends upon an equilibrium between the two
processes. This equilibrium varies markedly both over the globe
and throughout the year.
At very high altitudes a disrupted equilibrium is restored in
a matter of minutes; at lower levels in the stratosphere, in a
matter of weeks or months. In any event, repair takes place
rather quickly. Depletion of ozone can occur only by reducing
the equilibrium density of ozone molecules. This makes for
relatively insignificant depletions. No doubt many CFC molecules
have reached the ozone layer, but it is unlikely both that they
are depleting the ozone to the extent the activists say, and that
such damage, even if it existed, would take centuries to repair.
* Since the same narrow band of ultraviolet light breaks down
both CFCs, releasing their ozone-destroying chlorine, as well as
oxygen, creating ozone, there is a ``competition'' between the
two processes for this necessary solar energy. The probability
that an oxygen molecule will be broken apart, rather than a CFC
molecule, depends upon the relative abundance of the two gases in
the ozone layer. Calculations based on high-altitude CFC
samplings and data supplied by the National Oceanic and
Atmospheric Administration show 60,000 ozone molecules are
created for every chlorine atom released from a CFC molecule.
With this probability, how can the equilibrium density of the
ozone layer be materially reduced? In other words, the paucity
of measurable proof of depletion may be because depletion is not
actually occurring. It is of interest to note that surface
measurements by the National Oceanic and Atmospheric
Administration indicate that the total amount of ozone above the
U.S. is actually increasing.
* Unable to measure depletion in an unambiguous manner,
advocates of the theory have taken the ``hole'' in the layer over
Antarctica as indirect proof of loss of the layer over
midlatitudes. However, papers at last summer's international
ozone conference at Snowmass, Colo., cast doubt that this
phenomenon is a mirror of global ozone decline. Perhaps the
erosion of this ozone during the polar night is due to the same
interaction of the solar wind with the Earth magnetic field that
causes the auroras. It has been observed that this combination
can destroy the ozone. Solar wind is the product of solar
flares, which are becoming more frequent as sunspot activity
waxes.
Let us not blindly follow those environmental activists who
cry, ``The sky is falling,'' but let's continue to study the sky
until we know enough to make a sound decision regarding the
phasing out of our best refrigerants. Remember, before CFCs,
toxic ammonia and sulfur dioxide were used in our home
refrigerators.
------------------------------------
[The following is not part of the original article.]
1. Edward Edelson, ``The Man Who Knew Too Much'', Popular
Science, Vol. 234, No. 1 (January 1989), pp. 60-65, 102.
(Contains an interesting profile of F. Sherwood Rowland but
also assumes he is correct.)
* * *
Return to the ground floor of this tower
Return to the Main Courtyard
Return to Fort Freedom's home page