September 1993 (vol. 9, #6)
1601 N Tucson Blvd #9, Tucson AZ 85716 c 1993
Physicians for Civil Defense
National news media had some encouraging news about the ozone for a change.
According to a widely reported statement by James Elkins of the National Oceanic and Atmospheric Administration, the harmful depletion of Earth's protective layer could stop during the next century.
The reason (shown in a study published in the August 26, 1993, issue of Nature) is that the rate of stratospheric accumulation of CFC-11 and CFC-12 is slowing to as low as 2.7 parts per trillion per year. Between 1985 and 1988, the concentrations increased by at least 11 parts per trillion annually.
Of course, a decline in the rate of increase is not exactly the same as a decline. Yet, as is shown with respect to the rate of increase of the national debt, it is cause for celebration.
One difference between debt and CFCs is that with our debt, the trillions are in the numerator, not in the denominator.
One similarity between our stratospheric level of debt and the accumulation of stratospheric chemicals is that there is a doubling time. Between 1978 and 1992, the concentration of CFC-12 (freon) increased from about 250 parts per trillion to about 500 parts per trillion.
What are the effects of a doubled concentration?
Consider the effect of doubling the concentration of vanilla extract in cake batter: from 0.2 tsp in 250,000,000 gallons to 0.4 tsp in the same volume.
Of course, we are dealing with a reputedly voracious ozone eater, not with a mild taste-bud stimulant voracious enough to consume the several tons of ozone that are produced every second or the approximately 100 million tons produced every year. (For comparison, the total annual world production of CFCs was around 750,000 tons. About 111,000 metric tons of CFCs leak out of refrigeration equipment each year, according to an EPA estimate. A small fraction ends up in the stratosphere. Note that science writers say it is difficult for Mt. Erebus to spew chlorides into the stratosphere because it does not erupt ``explosively'' and its peak is several km below the base of the stratosphere [Science 260:1582, 1993]; refrigerators are more potent.)
Exactly how does a molecule of freon go about breaking down a molecule of O3? Is there a PAC-man moiety on the molecule that sucks an oxygen atom off any hapless ozone that happens to run into it? Or does the freon act as a catalyst for the reaction of O3 with something else?
Actually, CFCs themselves do not either act as a catalyst or react directly with the O3. The mechanism, as described in the Merck Index (11th ed.) is this: ``Photodecomposition occurs in the stratosphere via absorption of UV radiation and subsequent release of atomic chlorine which can catalyze ozone breakdown.'' This hypothesis was developed by F.S. Rowland, President of AAAS, one of the foremost apologists for the ozone hole theory, and published in Nature 249:810 (1974).
How fast do the CFCs decompose? According to Elkins, et al, (Nature 364:780-793, 1993), the mean atmospheric lifetime of CFC-11 is 55 ± 8 years and of CFC-12 is 140 ± about 50 years. CFCs are so stable that they are actually being used as tracers to follow ocean currents.
In her book Environmental Overkill, Dixy Lee Ray asks: ``If freon breaks down and releases its chlorine in the stratosphere, what happens to the rest of the molecule?'' She states that no breakdown products of CFCs have ever been detected in the stratosphere, although at least 192 chemical reactions and another 48 photochemical reactions have been identified there. In his recent article, Elkins makes no mention of any CFC decomposition products.
Another question is: If freon decomposes, how come it's still there a hundred years later?
The other stratospheric reactions are discussed extensively in the August 27, 1993, issue of Science. The series of reports begins with a summary: ``A cornerstone of our understanding of polar ozone loss is the heterogeneous conversions on particles of polar stratospheric clouds of inorganic chlorine from its less reactive components....'' (CFCs of course are organic compounds.) A sufficiently cold temperature and the clouds seem to be prerequisites. CFCs are not mentioned.
The ``ozone-destroying radical'' is ClO, chlorine monoxide. Ozone destruction is proportional to the concentration of ClO, not the concentration of CFCs. One factor that increases ClO is the presence of sulfuric acid aerosols from volcanoes such as Mount Pinatubo. This eruption set off global sirens in the winter of 1991-92 (see Civil Defense Perspectives, March, 1992). The government acted with great alacrity to accelerate the phase-out of CFCs before the scientific data could be analyzed.
The ozone layer has been carefully monitored for about two decades. Previously, the threat was the supersonic transport (SST). Congress cancelled two prototypes, England and France built the Concorde, and no environmental effects were observed. The CFC crisis was a godsend to the guardians of the ozone layer (see Fred Singer in Rational Readings on Environmental Concerns ed. by Jay Lehr).
There is no evidence of a long-term global downward trend in ozone levels (see graphs K. Towe, Science 257:727, 1992 and Fighting Chance Newsletter, Sept. 1992). There is no proof that CFCs cause significant ozone destruction. Therefore, the first annual Chicken Little Award for the most original and least-substantiated catastrophe was awarded to the ``Global Ozone Depletion Hoax'' in 1993 (Chicken Little Society, PO Box 276130, Boca Raton, FL 33427).
Nevertheless, the anti-ozone-eater radicals continue to defend us. Their achievements include the removal of 450 Salvation Army drop boxes. Thanks to environmental laws, freon-filled refrigerators and air conditioners left in the boxes had to be disposed of at costs of hundreds of dollars.
The first EPA enforcement action under the Clean Air Act prohibition against CFC release brought in an $18,000 fine against a New Hampshire construction firm engaged in a demolition project.
Supermarkets are already feeling the pinch due to a shortage of CFCs. The Food Marketing Institute estimated that modification of traditional cooling systems will cost up to $20,000 per store, plus $20,000 to $40,000 for the new coolant.
The Ozone Protection Campaign of Greenpeace is fighting a proposed exemption to the Montreal Protocol to allow the continued use of CFCs as a propellant for medical inhalers. Asthma sufferers are responsible for 0.5% of the CFCs released annually in the United States; they may have to be sacrificed to ``save'' the Planet's protective shield.
The rate of increase of stratospheric CFCs may have fallen. But the rate of cost increases due to the CFC ban are only beginning to accelerate.