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In the early 1970s, Rowland, alreadyan expert in the chemical reactions of radioactive isotopes and their useas tracers of chemical and biological processes, was stepping down as chairof the Irvine chemistry department and looking for a new avenue of investigation.As a graduate student at Chicago--where he was best known as a standoutvarsity basketball and baseball player--he had studied under Willard Libby.Libby would later win a Nobel for developing the carbon-14 dating technique,which uses the formation, by cosmic rays, of a long-lived radioisotopeincorporated into carbon dioxide to date plants and animal tissues up to45,000 years old. Much of the carbon-14 chemistry takes place in the lowerstratosphere, and Rowland now found himself drawn to environmental applicationsof radioactivity.
Attending a chemistry-meteorology workshop in early 1972,he learned that James Lovelock, a British biospheric scientist, had developeda highly sensitive instrument to measure trace organic compounds in theatmosphere. Taking air samples from shipboard in the North and South Atlantic,Lovelock had detected one particular CFC throughout the troposphere, the6-to-10-mile-high layer of the atmosphere between the earth's surface andthe stratosphere. Lovelock was enthusiastic about the finding: He thoughtthe CFC molecule would prove an excellent tag for air-mass movements andwind direction, since its chemical stability would prevent its removalfrom the atmosphere. Rowland, however, saw the matter differently.
"I knew that such a molecule could not remain inertin the atmosphere forever," Rowland says, "if only because solarphotochemistry at high altitudes would break it down." The next year,when he submitted his regular yearly proposal to the Atomic Energy Commission,which had supported his research for 17 years, Rowland posed a new question:What would eventually become of CFC molecules in the atmosphere?
With Molina, a photochemist from Mexico City who had justjoined his lab, Rowland began investigating the atmospheric fate of CFCs.The two knew that, like all molecular gases, the CFCs could be broken downinto their constituent atoms by short-wavelength ultraviolet radiationfrom the sun once they reached the stratosphere, from 12 to 23 miles up,where the sunlight is unshielded by the ozone layer.
After careful study, Rowland and Molina ruled out anychance that the CFCs might be rinsed out of the atmosphere by rainfall,as these organic compounds are insoluble in water. Nor was there any otherknown mechanism for the removal of the inert CFCs from the troposphere.Moreover, Lovelock's measurements suggested that the total amount of aparticular CFC in the troposphere was, in fact, equal to the total amountof it ever manufactured--which by that time, for all CFCs combined,totaled several million tons.
Although heavier than air, the CFC molecules would eventuallybounce up to the stratosphere, Rowland and Molina figured, and get zappedby the high-energy ultraviolet light, which would break off an atom ofchlorine. Each free chlorine atom would immediately react with a moleculeof ozone, a highly unstable form of molecular oxygen that contains threeatoms rather than the usual two. This would initiate a lengthy and complexchain reaction, destroying many thousands of ozone molecules for everychlorine atom unleashed in the stratosphere.
Rowland and Molina shared a chilling realization: A major,possibly irreversible, catastrophe had already been set in motion. Workingfrom rough calculations, they estimated that an eventual loss of approximately20 to 40 percent of the ozone was possible. This was a few days beforeChristmas of 1973.
"It was like staring into a pit and not being ableto see the bottom," Rowland recalls. "Molina and I had discussedthe overall calculations, and we were looking for flaws, and each of uswould sort of realize that as far as we could tell, there were no flaws.
"I'd come home at the end of the day," Rowlandcontinues, "and my wife would ask me how the work was going. 'Good,'I'd say, 'but it might mean the end of the world.'" Her reaction,Rowland says, was to immediately throw out every aerosol can in the house.
"Fifteen down," he says, "six billion togo."
Initially, Joan Lundberg Rowland, PhB'46, was one of veryfew people to act quickly on the news. There was no urgent phone call toWashington. "I didn't know anybody," her husband explains. "Notanybody in power, not anybody in the press."
In January 1974, convinced of the veracity and gravityof their findings, Rowland and Molina submitted an article to the Britishjournal Nature--where it languished for eight months. Even afterpublication, the news media paid little attention until the two chemistspresented their findings at a September meeting of the American ChemicalSociety in Atlantic City.
By that time, they had calculated that if CFC productioncontinued at the then current (peak) rate of about a million tons per year,between 7 and 13 percent of the ultraviolet-blocking ozone would be destroyedwithin a century. They told the meeting that society could expect a significantrise in skin cancer, crop damage, and perhaps even changes in global weatherpatterns.
Within a few weeks, their calculations for ozone losswere confirmed by Crutzen, a meteorologist then working at the NationalCenter for Atmospheric Research and the National Oceanic and AtmosphericAdministration in Boulder, Colorado, and by other groups as well. Stillothers produced numbers that suggested even more rapid destruction of theozone layer.
Now the press took notice, as did the environmentalists,who called for an immediate ban on the purchase of CFC aerosol sprays.The National Academy of Sciences announced it would mount a full-scaleinvestigation, and congressional hearings were soon under way.
Nor did the CFC industry remain inert. Its response wasto insist that ozone destruction was just a hypothesis, based on computerprojections--and that there was no proof the molecules would ever reachthe stratosphere, let alone behave so malevolently if they did. The industryposition was that CFCs should be regarded as innocent until proven guilty--promptingone government official to retort: "We cannot afford to give chemicalsthe same constitutional rights that we enjoy under the law." But governmentaction was not forthcoming; it was not until 1978 that the U.S. unilaterallybanned the use of CFCs in aerosol sprays. Other countries did not followsuit until the Antarctic ozone hole was found in 1984.
The 40-percent ozone depletion and the 10-percent increasein ultraviolet penetration discovered at the British Antarctic Survey'sHalley Bay station would lead to the landmark Montreal Protocol of 1987,in which many of the world's developed nations quickly agreed to halveCFC production by 1999. In 1990, as evidence of ozone loss continued tomount, delegates took the protocol a step further, agreeing to a totalphaseout by the year 2000. The catastrophic loss of ozone also quietedRowland's aerosol-industry detractors, who had mounted a withering attackon him since 1974.
"One of the people in the industry in an interviewsuggested that [Molina and I] were probably agents of the KGB," Rowlandrecalls. He had spent much of that 11-year period testifying at congressionalhearings and speaking at universities and scientific conferences aroundthe world. He had been elected to the National Academy of Sciences andthe American Academy of Arts and Sciences, and he received the AmericanPhysical Society's Leo Szilard Award for physics in the public interest.But he was also shunned by the chemistry community. From the time he andMolina published in 1974 until DuPont agreed to halt production of CFCsin 1988, he says, he did not get any applications from American graduatestudents or postdocs from outside the California system. "Americangrad students are pretty cagey," he says. Most of his university speakinginvitations during that time came from toxicology or atmospheric-sciencedepartments.
Still, Rowland--a man well known for his patience--ismagnanimous even to the point of defending his erstwhile industry adversaries."Every young person I ever knew getting into chemistry or physicsreally thought that they were on the good side and were trying to makelife better for people," he explains. "So it came as a disturbingshock to them that people were saying that some things that they had doneweren't actually making life better, but worse."
Rowland says that in a world polarized between tree huggerson one extreme and midnight dumpers on the other, he is closer to beingan environmentalist. But his natural home is with academic scientists;the 1974 Nature paper, he notes, was his 171st publication. In 1971he even drew the ire of environmentalists by showing that levels of mercuryfound in tuna were in fact no higher than those in specimens preserveddecades earlier.
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