An Ocean of Air (22 page)

One way to test this would be to use his instrument to measure CFCs in the ocean, going from the relatively polluted northern hemisphere to the less polluted southern. Direct pollution is much greater in the northern hemisphere, where there is much more land, and also much more industry. So, Lovelock persuaded the national funding agency, the Natural Environment Research Council (NERC), to give him a berth on the research ship
Shackleton,
and in November 1971 he set sail.

On his first day of measurements, Lovelock hit a snag. He quickly discovered that the "official" water samples provided for him would be useless. The problem lay not with his equipment, but with the ship itself.
Because the
Shackleton
was a research vessel, seawater was automatically pumped in from the bows so that scientists could have a continuous sample for their measurements. For normal measurements that would be fine. But Lovelock's measurements were far more delicate than the ship was used to. He needed to detect his CFCs at such faint traces that even the "clean" pipes through which the water passed were too contaminated for his purposes. He had to find another way of getting clean samples from the ocean surface.

Lovelock's first attempt at this was almost his last. He had decided on the simple stratagem of tying a bucket to a rope and dropping it over the side. However, the ship was steaming along at fourteen knots, and the bucket dragged so strongly in the water that it nearly pulled him in. Lovelock was irritated with himself, and said, "I should have calculated that a bucket dropped into water flowing past at 14 mph exerts a pull of over 100 pounds." Chastened, he asked the ship's technician for a smaller collecting bottle. But the only available ones were glass beakers from the laboratory, which would be far too fragile. It seemed it would be necessary to improvise.

Lovelock went along to the galley to see what they could offer him. Saucepans would be too difficult to maneuver on the end of his rope. But an old aluminum teapot, now retired from active duty, would be just the thing. From then onward Lovelock cheerfully used this teapot to scoop up his daily water samples, to the mingled alarm and scorn of many of the ship's other scientists.

The ship's crew were more tolerant of their practical, but eccentric, guest and seem to have taken his welfare very much to heart. Once, when he was collecting teapot samples in the midst of a storm, Lovelock noticed the bosun standing surreptitiously behind, ready to grab him should a wave look likely to wash him overboard.

As the ship crossed from the northern to the southern hemisphere, Lovelock noticed the difference. The air felt suddenly fresh and clean and much less hazy, and his CFC readings dropped as well. In the north they had been present at seventy parts per trillion, but the southern readings were slightly under half that. Still, the measurements proved what Lovelock had suspected: that CFCs were gradually showing up everywhere.

For a research trip costing a total of only a few hundred pounds, Lovelock's
Shackleton
voyage would prove momentous. He published the results in
Nature,
and then added a rider that he would come to regret. The point of the paper was to show that CFCs were appearing around the globe, but he didn't want to raise alarm in the minds of people who were unthinkingly afraid of anything "chemical." CFCs are after all inert; breathing them in at a few parts per trillion would cause no harm to anyone. That's why Lovelock wrote the phrase that would later haunt him. "The presence of these compounds," he said, "constitutes no conceivable hazard."

***

In the next few months, Lovelock's results wafted over the Atlantic to America, where they triggered a question in the mind of Sherwood ("Sherry") Rowland, a chemistry professor at the University of California, Irvine. Rowland realized that, even though Lovelock had found only tiny concentrations of CFCs in the atmosphere, together they added up to just about all of the CFCs being produced. That was odd, because most residents of the atmosphere last only a few weeks, before being reacted away or washed out in the rain. If Lovelock's measurements were right, it seemed that CFCs stayed around in the air for an extraordinarily long time. Rowland wasn't worried by this, just curious. He knew that nothing lasts forever. What, he wondered, would eventually happen to the CFCs?

Rowland was busy with his regular research involving radioactivity, as well as all the efforts involved in running his department. Fortunately, he had a bright young postdoctoral student to whom he could hand over the problem. Mario Molina had been born in Mexico City, the son of an ambassador. His background coupled with his undoubted intelligence had opened many doors, and he had studied in some of Europe's most prestigious institutions. But he preferred the American graduate program, and had recently finished his Ph.D. at Berkeley. He was looking for something to do next.

What Rowland proposed seemed like an interesting enough academic exercise: track the CFCs in the atmosphere, and work out what happens to them. The first thing Molina's calculations told him was that the lower part of the atmosphere held no fears for CFCs. They were insoluble in water,
so they couldn't be rained back down to the ground, and there were no other reactions that could destroy them. Eventually, they would have to make it above the atmospheric ceiling that contains all our wind, clouds, and weather, and emerge into the bright, rarefied levels of the stratosphere.

And that's where the trouble would start. As they floated upward, into the ozone layer, the CFCs would encounter ultraviolet rays for the first time. Any stray ray that hadn't yet been soaked up by some kamikaze ozone molecule could smash into a CFC molecule instead. Like a miniature bolt of electricity, this would turn each CFC into a monster.

The danger comes because CFCs contain the element chlorine. When chlorine is safely locked up in its molecular cage it's fine. But the moment it is released by the action of ultraviolet rays, a chlorine atom begins its rampage. Through a complicated series of reactions, any one chlorine atom effectively rips off the extra oxygen atom from an ozone (O3) molecule, leaving behind an ordinary molecule of oxygen (O2). The same atom of chlorine could then repeat the process with another molecule of ozone, and these two extras would then react together. The upshot: Two molecules of protective ozone turn into three molecules of useless oxygen (or, in the language of chemical equations: 2O3→3O2).

But the really troublesome part was how effectively these chlorines would do their job. Each chlorine atom would finish the cycle of reactions in the same state as it had started, so it would be free to repeat the process again and again. An atom of chlorine let loose in the stratosphere was like a miniature Pac-Man, gobbling up thousands, even tens of thousands, of ozone molecules before it finally reacted with something else and was taken out of the picture. According to Molina's calculations, a single chlorine atom could destroy, on average, 100,000 molecules of ozone.

Still, that would be dangerous only if there were enough chlorine atoms out there to make a serious difference to the ozone layer. Molina began some more calculations. He looked at the amount of CFCs now being released, calculated how long it would take these molecules to waft up to the stratosphere, and ... Molina was aghast. In one hundred years' time, he calculated, the ozone layer would have lost a full 10 percent of its molecules. He immediately raced off to see Rowland. They checked and
rechecked the calculations, but the same answer kept reappearing. And 10 percent was only a start. If their emissions remained unchecked, CFCs would pose a serious threat to all life on Earth. Rowland's mind was heavy when he returned home that night. "The work is going well," he said to his wife, "but it looks like the end of the world."

The next few weeks saw Molina and Rowland going back over the figures again and again. Before they dared publish, they had to be absolutely sure of their findings. When they were confident their calculations were right, Rowland's wife, Joan, collected every aerosol can containing CFCs in the house and threw them all away.

News of the work leaked out onto the scientific grapevine. Though he still hadn't met or talked to the pair, Jim Lovelock heard about their predictions and was intrigued. He thought it likely that CFCs would make it up to the stratosphere, and wondered whether they truly were split apart there, as the Molina-Rowland theory suggested. Never one to pass up an opportunity to test an interesting theory, Lovelock set off in search of a plane.

His first stop was the Meteorological Office, which had regular flights up to the stratosphere. But the bureaucracy there was awful. He would have to wait at least two years while the requisite safety checks could be made on his equipment and all the right papers could be stamped.

Lovelock was too impatient for that. He chatted instead to some friends at the Ministry of Defense. Did they, perhaps, know of any stratospheric flights coming up that might have room for one smallish passenger and his even smaller air-sampling cylinders? Certainly, came the reply. A Hercules aircraft was scheduled for a test flight up to 45,000 feet, and Lovelock was welcome to join it. At that time of year, the stratosphere started at thirty thousand feet, so he would have three full miles of stratosphere in which to make his measurements. Of course, officially speaking he would not be on board, so there would be no compensation for his family if it crashed. On the other hand, there would be no charge, and—a blessed relief—no paperwork.

A few weeks later, Lovelock was on the flight deck as the Hercules took off from Lyneham airfield in Wiltshire. As the plane climbed, he sat next to the engineer and took his air samples. On the way down, the plane
made some practice maneuvers, including recovering from a stall. Lovelock rather nervously asked what would happen if the plane went into a spin. "No worry at all," came the pilot's confident reply. "This aircraft would make no more than half a turn before the wings came off." After that, says Lovelock, he kept quiet.

As soon as Lovelock returned home he analyzed his samples. They showed a steady level of CFCs in the lower atmosphere, and then a decline in the stratosphere, just as Molina and Rowland had predicted. It seemed their theory was right.

***

Molina and Rowland's findings appeared in
Nature
in June 1974. And the reaction was ... silence.

The two researchers had braced themselves for the onslaught that would surely follow the publication of their paper, but nobody seemed to have noticed their alarming news. The problem was they had been so careful not to overstate their case that they had buried the implications in diffident scientist-speak, with no alarm bells or warning sirens attached. "It seems quite clear that the atmosphere has only a finite capacity for absorbing [chlorine] atoms produced in the stratosphere, and that important consequences may result...[with the] possible onset of environmental problems," they had written in the middle of an obscure paragraph toward the end of the paper.

These "possible environmental problems" involved the potential destruction of the layer that protects us from deadly space rays, but obviously this had not come through. Molina and Rowland decided it was time to make their message more explicit, both to the scientific community and to the world at large. In September there would be a meeting of many of the world's most prominent chemists, in Atlantic City, under the auspices of the American Chemical Society. This would be the perfect opportunity to present the work directly to their colleagues. But they decided they would also do something more radical; they would hold a press conference.

The relationship between scientists and the press is an uncomfortable one at the best of times. If scientists acquire anything approaching media
gloss, they immediately attract both scorn and jealousy from many of their peers. There is even a name for this, the "Sagan effect," after astronomer Carl Sagan, who through his television programs woke many people around the world to the wonders of the cosmos, yet was viewed with increasing suspicion by other astronomers. The general attitude among scientists is that usually, it is better not to get involved with the media. If you must get involved, do not, whatever you do, take a political or social stand. Scientists are there to report their results. Let the world interpret them if it must.

This at least was the prevailing attitude of the time. But Molina and Rowland were about to break these rules. At their press conference, they carefully explained their results and the scientific significance. Their predictions had become gloomier; the new calculations suggested a 5 percent ozone loss by 1995 and a 30 percent loss by 2050. Then Molina and Rowland stepped over the normal scientific bounds. They called for a worldwide ban on CFCs.

Ban a product on which rested an eight-billion-dollar industry? On the basis of a few calculations? The CFC industry was horrified. And yet the moment was propitious for sounding warnings about potential environmental harm. The early 1970s marked the beginning of the environment as a political issue, a time when the green movement had just begun to stir to life. The Environmental Protection Agency had been born a few years earlier, after Rachel Carson had warned of the dangers of pesticides in her seminal book
Silent Spring.
Widespread excitement at the pace of technological change had given way to worry about the harm that this technology might cause. Radios around the country were broadcasting Joni Mitchell, singing her environmental fable: "Don't it always seem to go that you don't know what you've got till it's gone?"

On Capitol Hill, December 11, 1974, Representative Paul G. Rogers, chair of the House Subcommittee on Public Health and the Environment was introducing a hearing called in response to Molina and Rowland's findings. "The entire matter rings of a science fiction tale," he said. "One we have all heard: how a planet, now barren, was destroyed by its very inhabitants. Had not the evidence been brought forth by such reputable men of science, it would seem like bitter, black humor—that the earth may be endangered and the villains of the situation are billions of aerosol cans."