How the Real Scientists Feel
So how did atmospheric physicists, climatic specialists, and others with scientific credentials feel about the issue? To find out, Dr. Arthur Robinson, president and research professor of the Oregon Institute of Science and Medicine, also publisher of the newsletter Access to Energy, in February 1998, conducted a survey of the professional field by circulating a petition calling for the government to reject the Kyoto agreement of December 1997, on the grounds that it would harm the environment, hinder science, and damage human health and welfare; that there was no scientific evidence that greenhouse gases were or were likely to cause disruption of the climate; and on the contrary there was substantial evidence that such release would in fact be beneficial. 165 After six months the petition had collected over seventeen thousand signatures.
At about the same time the German Meteorologisches Institut Universitat Hamburg and Forschungszentium, in a survey of specialists from various branches of the climate sciences, found that 67 percent of Canadian scientists rejected the notion that any warming due to human activity is occurring, while in Germany the figure was 87 percent, and in the US, 97 percent. 166 Some consensus for Kyoto!
After all the vivid depictions of drowning coastlines, devastated landscapes, and hunger-crazed mobs fighting amid the ruins of derelict cities, I can't think of a better contrasting note to finish on than the words of Arthur Robinson and his son, Zachary, from the piece cited ealier:
What mankind is doing is moving hydrocarbons from below the ground and turning them into living things. We are living in an increasingly lush environment of plants and animals as a result of the carbon dioxide increase. Our children will enjoy an Earth with twice as much plant and animal life as that with which we are now blessed. This is a wonderful and unexpected gift from the industrial revolution.
Holes in the Ozone Logic—
But Timely for Some
— Cui Bono? (Who Benefits?)
The early 1990s saw the coming to a crescendo of the panic over alleged depletion of the ozone layer being caused by CFCs. The following is based on an article of mine that appeared in Omni magazine in June 1993. It's reproduced here with a few minor changes.
Man-made chlorofluorocarbons, or CFCs, we're told, are eating away the ozone layer that shields us from ultraviolet radiation, and if we don't stop using them now, deaths from skin cancer in the United States alone will rise by hundreds of thousands in the next half century. As a result, over eighty nations are about to railroad through legislation to ban one of most beneficial substances ever discovered, at a cost that the public doesn't seem to comprehend, but which will be staggering. It could mean having to replace virtually all of today's refrigeration and air-conditioning equipment with more expensive types running on substitutes that are toxic, corrosive, flammable if sparked, less efficient, and generally reminiscent of the things that people heaved sighs of relief to get rid of in the 1930s.
And the domestic side will be only a small part. The food industry that we take for granted depends on refrigerated warehouses, trains, trucks, and ships. So do supplies of drugs, medicines, and blood from hospitals. Whole regions of the sunbelt states have prospered during the last forty years because of the better living and working environments made possible by air conditioning. And to developing nations that rely totally on modern food-preservation methods to support their populations, the effects will be devastating.
Now, I'd have to agree that the alternative of seeing the planet seared by lethal levels of radiation would make a pretty good justification for whatever drastic action is necessary to prevent it. But when you ask the people who do have the competence to know: scientists who have specialized in the study of atmosphere and climate for years, a very different story emerges. What they point out, essentially, is that the whole notion of the ozone layer as something fixed and finite, to be eroded away at a faster or slower rate like shoe leather, is all wrong to begin with—it's simply not a depletable resource; that even if it were, the process by which CFCs are supposed to deplete it is highly speculative and has never actually been observed to take place; and even if it did, the effect would be trivial compared to what happens naturally. In short, there's no good reason for believing that human activity is having any significant effect at all.
Ozone Basics
To see why, let's start with the basics and take seashores as an analogy. Waves breaking along the coastline continually generate a belt of surf. The surf decomposes again, back into the ocean from where it came. The two processes are linked: Big waves on stormy days create more surf; the more surf there is to decay, the higher the rate at which it does so. The result is a balance between the rates of creation and destruction. Calmer days will see a general thinning of the surfline, and possibly "holes" in the more sheltered spots—but obviously the surf isn't something that can run out. Its supply is inexhaustible for as long as oceans and shores exist.
In the same kind of way, ozone is all the time being created in the upper atmosphere, by sunshine, out of oxygen. A normal molecule of oxygen gas consists of two oxygen atoms joined together. High-energy ultraviolet radiation, known as UV-C, can split one of these molecules apart—a process known as "photodissociation"— into two free oxygen atoms. These can then attach to another oxygen molecule to form a three-atom species, which is ozone. It's produced mainly in the tropics above 30 kilometers altitude, where the ultraviolet flux is strongest. The ozone sinks and moves poleward to accumulate in lower-level reservoirs extending from 17 to 30 kilometers altitude—the so-called ozone "layer."
Ozone is destroyed by chemical recombination back into normal oxygen in several ways: by reaction with nitrogen dioxide (produced by high-altitude cosmic rays); through ultraviolet dissociation by the same UV-C that creates ozone; and also by a less energetic band known as UV-B, which is not absorbed in the higher regions. Every dissociation of an oxygen or ozone molecule absorbs an incoming UV photon, and that is what gives this part of the atmosphere its ultraviolet screening ability.
The height and thickness of the ozone reservoir region are not constant, but adjust to accommodate variations in the incoming ultraviolet flux. When UV is stronger, it penetrates deeper before being absorbed; when weaker, UV penetration is less. Even if all the ozone were to suddenly vanish, there would still be 17 to 30 kilometers of hitherto untouched, oxygen-rich atmosphere below, that would become available as a resource for new ozone creation, and the entire screening mechanism would promptly regenerate. As Robert Pease, professor emeritus of physical climatology at the University of California, Riverside, says, "Ozone in the atmosphere is not in finite supply." 167 In other words, as in the case of surf with oceans and shores, it is inexhaustible for as long as sunshine and air continue to exist.
The Depletion Controversy
Even though the physics makes it difficult to see how, the notion of something man-made destroying the ozone layer has always fascinated an apocalyptic few, who have been seeking possible candidates for over forty years. According to Hugh Ellsaesser, retired and now guest scientist at the Atmospheric and Geophysical Sciences Division of the Lawrence Livermore National Laboratory, "There has been a small but concerted program to build the possibility of man destroying the ozone layer into a dire threat requiring governmental controls since the time of CIAP." 169 (Climatic Impact Assessment Program on the supersonic transport, conducted in the early seventies.)
In the 1950s it was A-bomb testing, in the sixties the SST, in the seventies spacecraft launches and various chemicals from pesticides to fertilizers. All of these claims were later discredited, and for a while the controversy died out. 170 Then, in 1985–1986, banner headlines blared that a huge ozone hole had been discovered in the Antarctic. This, it was proclaimed, at last confirmed the depletion threat, the latest version of which had been around for just under a decade.
In 1974, two chemists at the University of California, Irvine, Sherwood Rowland and Mario Molina, hypothesized that ozone might be att
acked by CFCs—which had come into widespread use during the previous twenty years. 171 Basically, they suggested that the same chemical inertness that makes CFCs noncorrosive, nontoxic, and ideal as a refrigerant would enable them to diffuse intact to the upper atmosphere. There, they would be dissociated by high-energy ultraviolet and release free atoms of chlorine. Chlorine will combine with one of the three oxygen atoms of an ozone molecule to produce chlorine monoxide and a normal two-atom oxygen, thereby destroying the ozone molecule. The model becomes more insidious by postulating an additional chain of catalytic reactions via which the chlorine monoxide can be recycled back into free chlorine, hence evoking the specter of a single chlorine atom running amok in the stratosphere, gobbling up ozone molecules like Pac Man. Scary, vivid, sensational: perfect for activists seeking a cause, politicians in need of visibility, and the media, always hungry for anything sensational. But it doesn't fit with a few vital facts.
First, CFCs don't rise in significant amounts to where they need to be for UV-C photons to break them up. Because ozone absorbs heat directly from the sun's rays, the stratosphere exhibits a reverse temperature structure, or thermal "inversion"—it gets warmer with altitude, rather than cooler. As Robert Pease points out, "This barrier greatly inhibits vertical air movements and the interchange of gases across the tropopause [the boundary between the lower atmosphere and the stratosphere], including CFCs. In the stratosphere, CFC gases decline rapidly and drop to only 2 percent of surface values by 30 kilometers of altitude. At the same time, less than 2 percent of the UV-C penetrates this deeply." 172 Hence the number of CFC splittings is vastly lower than the original hypothesis assumes, for same reason that there aren't many marriages between Eskimos and Australian aborigines: the partners that need to come together don't mix very much.
For the UV photons that do make it, there are 136 million oxygen molecules for them to collide with for every CFC—and every such reaction will create ozone, not destroy it. So even if we allow the big CFC molecule three times the chance of a small oxygen molecule of being hit, then 45 million ozone molecules will still be created for every CFC molecule that's broken up. Hardly a convincing disaster scenario, is it?
Ah, but what about the catalytic effect, whereby one chlorine atom can eat up thousands of ozone molecules? Doesn't that change the picture?
Not really. The catalysis argument depends on encounters between chlorine monoxide and free oxygen atoms. But the chances are much higher that a wandering free oxygen atom will find a molecule of normal oxygen rather than one of chlorine monoxide. So once again, probability favors ozone creation over ozone destruction.
At least 192 chemical reactions occur between substances in the upper stratosphere, along with 48 different, identifiable photochemical processes, all linked through complex feedback mechanisms that are only partly understood. 173 Selecting a few reactions brought about in a laboratory and claiming that this is what happens in the stratosphere (where it has never been measured) might be a way of getting to a predetermined conclusion. But it isn't the end of the world.
But surely it's been demonstrated! Hasn't one thousand times more chlorine been measured over the Antarctic than models say ought to be there?
Yes. High concentrations of chlorine—or to be exact, chlorine monoxide. But all chlorine atoms are identical. There is nothing to link the chlorine found over the Antarctic with CFCs from the other end of the world. It might also be mentioned that the measuring station at McMurdo Sound is located 15 kilometers downwind from Mount Erebus, an active volcano currently venting 100 to 200 tons of chlorine every day, and which in 1983 averaged 1,000 tons per day. Mightn't that have more to do with it than refrigerators in New York or air conditioners in Atlanta?
World CFC production is currently about 1.1 million tons annually, 750,000 tons of which is chlorine. Twenty times as much comes from the passive outgassing of volcanoes. This can rise by a factor of ten with a single large eruption—for example that of Tambora in 1815, which pumped a minimum of 211 million tons straight into the atmosphere. Where are the records of all the cataclysmic effects that should presumably have followed from the consequent ozone depletion?
And on an even greater scale, 300 million tons of chlorine are contained in spray blown off the oceans every year. A single thunderstorm in the Amazon region can transport 200 million tons of air per hour into the stratosphere, containing 3 million tons of water vapor. On average, 44,000 thunderstorms occur daily, mostly in the tropics. 174 Even if we concede to the depletion theory and allow this mechanism to transport CFCs also, compared to what gets there naturally the whiff of chlorine produced by all of human industry (and we're only talking about the leakage from it, when all's said and done) is a snowflake in a blizzard.
Despite all that, isn't it still true that a hole has appeared in the last ten years and is getting bigger? What about that, then?
In 1985 a sharp, unpredicted decline was reported in the mean depth of ozone over Halley Bay, Antarctica. Although the phenomenon was limited to altitudes between 12 and 23 kilometers, and the interior of a seasonal circulation of the polar jet stream known as the "polar vortex," it was all that the ozone-doomsday pushers needed. Without waiting for any scientific evaluation or consensus, they decided that this was the confirmation that the Rowland-Molina conjecture had been waiting for. The ominous term "ozone hole" was coined by a media machine well rehearsed in environmentalist politics, and anything that the scientific community had to say has been drowned out in the furor that has been going on ever since.
Missing from the press and TV accounts, for instance, is that an unexpectedly low value in the Antarctic winter-spring ozone level was reported by the British scientist Gordon Dobson in 1956—when CFCs were barely in use. In a forty-year history of ozone research written in 1968, he notes: "One of the most interesting results . . . which came out of the IGY [International Geophysical Year] was the discovery of the peculiar annual variation of ozone at Halley Bay." 175 His first thought was that the result might have been due to faulty equipment or operator error. But when such possibilities had been eliminated, and the same thing happened the following year, he concluded: "It was clear that the winter vortex over the South Pole was maintained late into the spring and that this kept the ozone values low. When it suddenly broke up in November both the ozone values and the stratosphere temperatures suddenly rose." A year after that, in 1958, a similar drop was reported by French scientists at the Antarctic observatory at Dumont d'Urville—larger than that causing all the hysteria today. 176
These measurements were on the edge of observational capability, especially in an environment such as the Antarctic, and most scientists regarded them with caution. After the 1985 "discovery," NASA reanalyzed their satellite data and found that they had been routinely throwing out low Antarctic ozone readings as "unreliable."
The real cause of the variation is slowly being unraveled, and while some correlation is evident with volcanic eruptions and sunspot cycles, the dominant factor appears to be the extreme Antarctic winter conditions, as Dobson originally suspected. The poleward transportation of ozone from its primary creation zones over the tropics does not penetrate into the winter vortex, where chemical depletion can't be replaced because of the lack of sunshine. Note that this is a localized minimum relative to the surrounding high-latitude reservoir regions, where global ozone is thickest. As Hugh Ellsaesser observes, "The ozone hole . . . leads only to spring values of ultraviolet flux over Antarctica a factor of two less than those experienced every summer in North Dakota." 177
But isn't it getting bigger every year? And aren't the latest readings showing ozone depletion elsewhere too?
In April 1991, EPA Administrator William Reilly announced that the ozone layer over North America was thinning twice as fast as expected, and produced the figures for soaring deaths from skin cancer. 178 This was based on readings from NASA's Nimbus-7 satellite. I talked to Dr. S. Fred Singer of the Washington-based Science and Environmental Policy Proj
ect, who developed the principle of UV backscatter that the ozone monitoring instrument aboard Nimbus-7 employs. "You simply cannot tell from one sunspot cycle," was his comment. "The data are too noisy. Scientists need at least one more cycle of satellite observations before they can establish a trend." In other words, the trend exists in the eye of the determined beholder, not in any facts that he beholds.
February this year (1992) saw a repeat performance when a NASA research aircraft detected high values of chlorine monoxide in the northern stratosphere. Not of CFCs; nor was there any evidence that ozone itself was actually being depleted. Nor any mention that the Pinatubo volcano was active at the time. Yet almost as if on cue, the U.S. Senate passed an amendment only two days later calling for an accelerated phaseout of CFCs. It just so happened that NASA's budget was coming up for review at the time. After getting their funding increase they have since conceded that perhaps the fears were premature, and the Great American Ultraviolet Catastrophe isn't going to happen after all.
Creating Catastrophe: The Wizards of Ozone
But apart from all that, yes, world mean total ozone declined about five percent from 1979 to 1986. So what? From 1962 to 1979 it increased by five and a half percent. And since 1986 it has been increasing again—although that part is left out of the story that the public gets. On shorter timescales it changes naturally all the time and from place to place, and hence surface ultraviolet intensity is not constant and never was. It varies with latitude, i.e., how far north or south from the equator you are, with the seasons, and with solar activity. And it does so in amounts that are far greater than those causing all the fuss.
Kicking the Sacred Cow Page 28
