An Ocean of Air

by Gabrielle Walker

  ***

  In 1920s America, a certain industrialist was preparing to make another of his inventions. Thomas Midgley was a jovial man, full of enthusiasm and energy. He had hordes of friends, and—amazingly, given his many successes—scarcely any enemies. His face, round like a full moon, beamed with bonhomie, especially when he found a new engineering puzzle to solve. Even in his spare time he was captivated by mechanical problems. When he was walking in the countryside, he spent half his time supine, trying to figure out the principles behind the construction of anthills. When he took up golf and discovered the poor quality of the greens, he began experimenting at home with new kinds of grasses. He was a born inventor.

  It's not surprising that Midgley had an inventor's eye—his whole family loved to experiment. His mother's father had devised the circular saw, and his own father held a number of patents for new kinds of tires and bicycle wheels. Midgley's first job was in "Inventions Department No. 3" of the National Cash Register Company in Dayton, Ohio, and then in 1916 he moved to the research division of the General Motors Company. It was there that he would make his most famous inventions, materials that would prove to be useful, powerful, and ultimately deadly.

  For though he didn't know it at the time, Midgley was destined to be terribly unlucky with his inventions. One of the first things he did at General Motors was to recommend putting lead in gasoline. He had a good reason for this—indeed, it was hailed as an ingenious solution to a most annoying problem. Cars and planes were relatively recent inventions, and all attempts to make their engines more efficient came up against the same problem: Uneven combustion meant that they made an infuriating knocking sound and operated poorly. Midgley wanted to find something that he could add to the gasoline to make it burn more evenly. At first, he had little success. He tried everything "from melted butter and camphor to ethyl acetate and aluminum chloride ... and most of them had no more effect than spitting in the Great Lakes." (He did discover that compounds containing tellurium and selenium seemed to work, but they had a bizarre side effect, making the workers reek with the smell of garlic.)

  Finally, in December 1921, after working his way through thousands of compounds, Midgley discovered that adding lead to the mix solved everything. He had to overcome a certain amount of prejudice from consumers who thought that lead in gasoline might be dangerous. (It is. It accumulates in humans and causes several debilitating diseases, which is why it is now banned.) But at the time, Midgley's well-meaning arguments prevailed. The first leaded gasoline went on sale in 1923, and it quickly became universal. Engines in cars and planes could now work much more efficiently, and Midgley was on his way to becoming a hero.

  Midgley's next invention arose from a problem that came to him from Frigidaire, the refrigeration division of General Motors. Mechanical refrigeration was a recent arrival on the technological scene. Before then, ice had to be shipped down from Canada to provide a coolant of sorts, but it was expensive, weather-dependent, and not widely available. Hospital wards in the southern United States were often unbearable during the summer, with the heat killing off as many people as actual illnesses. Food spoiled rapidly, and "tropical" diseases like yellow fever and malaria were still rampant there. So mechanical refrigeration seemed like a miracle. Buildings could be air-conditioned, families could keep food for days without it spoiling, and people could make their own ice even in midsummer.

  Refrigerators work by successively liquefying and re-evaporating the material inside their pipes. The material starts out as a gas, but in the pipes outside the fridge the gas is squeezed until it turns into a liquid—which releases heat energy and explains why the backs of refrigerators get hot. This liquid is then carried inside the fridge, where it is allowed to expand until it turns back into a gas. This process is the exact opposite of the liquefaction. It soaks up heat energy from its surroundings, cooling down the fridge in the process.

  The problem lay in the choice of material that could be so readily squeezed into a liquid and then sprayed back into a gas. To date, every refrigerant that anyone tried had some kind of health hazard attached—some were toxic, some were flammable, and some were both. As long as these gases stayed safely in their closed pipes, that wasn't a problem. But somewhere, sometime, there would be a leak—and that's where the trouble started. By 1929 Frigidaire had sold one million domestic refrigerators, and the accident toll was mounting. People moved their fridges out onto the back porch. After a fatal leak in a Cleveland medical center, hospitals scarcely dared use them at all. Frigidaire's engineers even suggested returning exclusively to the first refrigerant they had tried—sulfur dioxide. Yes, it was highly poisonous, but at least its irritating choking smell gave immediate warning of danger.

  Midgley's task was to find a cure for these ills. He needed a refrigerant that was nonflammable and nonpoisonous. It had to be absolutely safe.

  Thomas Midgley set about this assignment with his usual dedication. He began by imagining various chemicals and calculating their likely properties, "plotting boiling points, hunting toxicity data, corrections; slide rules and log paper, eraser dirt and pencil shavings, all the rest of the paraphernalia that take the place of tea leaves and crystal spheres in the life of the scientific clairvoyant." In the end, Midgley came up with a compound that seemed absolutely perfect. It had the right boiling point; it didn't burn; in fact, if his calculations were right, nothing would ruffle its chemical calm.

  All that remained was to make sure this new chemical wouldn't be poisonous. And here, in one of the many ironies that dogged Midgley's inventions, he came very close to abandoning the whole project. To prepare his new chemical, Midgley had bought five small bottles of antimony trifluoride. He reached for one of these bottles at random and made a few grams of what would later be dubbed Freon. Then he placed it in a glass jar with a guinea pig. He watched and waited to see how the animal reacted to breathing the new gas. The guinea pig was completely unconcerned. It seemed that his new chemical was nontoxic, as Midgley had predicted.

  But just to be sure, Midgley made another batch starting with a second bottle of antimony trifluoride. This time, the guinea pig died instantly. Midgley was confused. Why should his Freon be poisonous to one animal and not the other? Cautiously, he sniffed at a third bottle of antimony trifluoride. What he smelled there was unmistakable: phosgene, the killer gas of the Great War. Midgley discovered that four out of his five bottles of antimony trifluoride had contained this fatal impurity. It was just luck that, for his first try, he had used the only pure sample in his batch. If he had picked up one of the others, and the first guinea pig had died, would he have continued with his research? Or would he have abandoned Freon for something else that would ultimately prove less deadly to the atmosphere?

  "The chances were four to one against us," he said later, "and I often wonder if the sudden decease of our first guinea pig would not have so completely shaken our confident expectation that our new compound could not possibly be toxic, that—well I still wonder if we would have been smart enough to have continued the investigation. Even if we had, the chances were still three to one against our using the one pure sample. I still wonder."

  Now, using only pure samples, Midgley confirmed his first positive experiment. From then onward, all the guinea pigs were fine. Freon had no apparent impact on man or beast. It was every bit as inert as his calculations had suggested. It was, in other words, completely "safe."

  Midgley announced his invention at a meeting of the American Chemical Society in Atlanta in April 1930. He demonstrated the safety of his new gas with irrepressible showmanship: In front of a rapt crowd of chemists he took in a deep breath of Freon, and then slowly exhaled it over a lit candle. The candle went out.

  Freon wasn't only nonflammable and nontoxic; it was also heavier than air. Salesmen liked to demonstrate this by pouring Freon down a staircase that had a lit candle on each step. Though the gas was invisible, you could track its progress as it extinguished one candle after another. />
  Midgley's new chemical was an immediate hit. Together with its family of related chemicals (known collectively as CFCs, or chlorofluorocarbons, so named because they contain chlorine, fluorine, and carbon), it quickly became America's refrigerant of choice. Because it was so safe, Midgley's company agreed to sell it to all of their competitors, and soon it was universal in refrigerators throughout the land.

  With the Second World War came a new use for Freon. Soldiers in the Pacific jungles were being struck down with insect-born diseases, so the U.S. Department of Agriculture invented the "bug bomb," a portable insecticide dispenser that used Freon as a propellant to spray the insecticide exactly where it was needed. This was the origin of aerosol spray cans, in which everything from deodorant to hair spray could be neatly, precisely delivered with the help of Midgley's Freon. Next on the scene was the dry cleaning industry. Then CFCs turned out to be perfect for making foam rubber for furniture. It must have seemed that Freon was a chemical panacea.

  And yet, by inventing his "safe" new chemical and offering it to the world, Midgley had created a monster.

  At first nobody had any inkling of this. During his lifetime, Midgley was feted for his achievements. He received almost every major prize in chemistry as well as dozens of other awards and honorary degrees. (He didn't get the Nobel prize, though his work would later inspire one.) The citation for one such award, an honorary doctorate from Ohio State University in 1944, declared with full sincerity:

  The research work of Mr. Midgley has received wide recognition, as is evidenced by the great number of distinctions which have come to him from those groups best qualified to evaluate his contributions to human knowledge. Through experience, the layman will also testify his indebtedness to one who has contributed so greatly to more pleasant and efficient living. He has made science a liberator, and we rejoice with him in the satisfactions that must be his in seeing the fruits of his labor. Posterity will acknowledge their permanent value.

  In 1947, three years after Midgley's death, his former boss Charles Kettering made a similar point during an address to the National Academy of Sciences. Kettering recalled the words of the minister at Midgley's funeral: "We brought nothing into this world, and it is certain we can carry nothing out." "It struck me then," said Kettering, "that in Midgley's case it would have seemed so appropriate to have added this: 'but we can leave a lot behind for the good of the world.'"

  Midgley, poor unlucky Midgley, would certainly leave a striking legacy. In his cheerful, pleasant, untiring efforts to improve the world around him, he would be inadvertently responsible for more damage to Earth's atmosphere than any other single organism that has ever lived.

  Midgley himself never lived to see how much trouble he had accidentally caused. In autumn 1940, he suffered an acute attack of polio, which left him paralyzed in both legs. As soon as the worst was over, Midgley calculated the statistical probability that a man of fifty-one would catch the disease, and concluded that it was "substantially equal to the chances of drawing a certain individual card from a stack of playing cards as high as the Empire State Building." It was, he added, "my tough luck to draw it."

  Still, he continued to direct research work from his home, giving speeches by telephone and even devising a harness and pulley to lift him out of bed. But on the morning of November 2, 1944, age fifty-five, Thomas Midgley somehow became caught up in the pulley's ropes. He was strangled to death by his own invention.

  The first hints that something might be awry with Midgley's miraculous refrigerants came from a gentle, quiet-spoken man with soft curls, bright eyes, and a wistful smile. In spirit and interests, Jim Lovelock is far more like the natural philosophers of old than the specialized researchers of today. He is famously independent, operating—most unusually for a modern professional scientist—from a laboratory in his own backyard. He is also impishly contrary. A colleague once described him as "the most creatively mischievous mind I've ever encountered."

  Lovelock had never wanted to be beholden to a university or institution. Still, he tried the "normal" route at least for a while. Having trained as a chemist in the 1930s, he started working for the Medical Research Council in London. But he was increasingly uncomfortable in his conventional—he would say hidebound—surroundings. While his colleagues all wore the normal white lab coats, he insisted on a surgeon's outfit, to avoid being "uniform." By 1959, with his fortieth birthday approaching, Lovelock had had enough. "Every day I would go to the Institute, do my research, and come home again. I felt like the man in the limerick:

  There was a young man who said, "Damn,

  It appears to me that I am,

  A being who moves

  In predestinate grooves;

  Not a car, not a bus, but a tram."

  The thought of these tramways conducting him all the way to the grave made Lovelock feel queasy. He told his boss he was quitting and fled—first to Houston, Texas, to work at the university for a while and save up some money from what proved to be a large American salary, and then back to England to set up his own laboratory in a tiny village in Wiltshire, southern England.

  Lovelock quickly realized there were some practical barriers to being an independent scientist. For one thing, it was more difficult to get academic journals to take you seriously if your official address was a remote, thatched cottage instead of a prestigious institution. Trying to get hold of laboratory supplies was even worse. Even in those less terrorist-sensitive times, if you wrote from a residential address trying to order a few kilograms of potassium cyanide, say, or a piece of some radioactive substance, you were more likely to get a visit from the police than from the delivery van. To get around this problem, Lovelock decided to start up a company, which he called Brazzos. His reason for this name was typically practical. The company was named after the river Brazos, near Houston. The misspelling was because it cost twenty-five pounds a shot to compare a proposed company name with those already taken. After a couple of false tries, Lovelock picked a name he was sure nobody would have used.

  Under the umbrella of Brazzos, Lovelock quickly picked up consultancy contracts from various large companies who already knew of his work for the Medical Research Council. Now he was free to pursue his inventive, sometimes outlandish, scientific ideas. Probably the most famous of these is his suggestion that life on Earth regulates its own environment to prevent the planet from getting too hot or cold, or otherwise too inimical. He came across this notion while working on experiments to detect life on Mars at NASA's Jet Propulsion Lab in 1965. While thinking about the atmosphere on Mars and our other nearest neighbor, Venus, Lovelock was struck by how different they both are from Earth. Mars is frigid, Venus searingly hot, and yet both have atmospheres whose chemistry is settled and fits sensibly with the equations. Earth, on the other hand, does not. Its atmosphere is full of ultrareactive oxygen, for example, which by chemical rights shouldn't be there at all.

  The oxygen came from life. It is there, Lovelock realized, only because living things had dramatically altered their environment to suit themselves. After that, he began finding other examples in which life had shaped the planet and been shaped in its turn. Wherever he looked, Lovelock discovered an intimate interaction between life, air, and rock. It was almost, he thought, as if the planet itself were alive.

  With typical romanticism, he named his theory Gaia after the Greek goddess of the Earth. (His neighbor, novelist William Golding of Lord of the Flies fame, suggested the name, prompting Lovelock to say that "few scientists have had their theories named by so competent a wordsmith.") Broadly speaking, the theory was right—there are many ways that living things have adapted the planet for their own uses. However, the name Gaia, coupled with the holistic "hippie" feel of Lovelock's theory, made many of his peers look at him askance. Though his work was both careful and sound, and published in the world's most eminent journals, some scientists still didn't trust it. Lovelock didn't particularly mind. When one eminent scientist described him as a "holy f
ool," he was even proud, though with his typical self-deprecating humor he did wonder whether the scientist had meant "wholly."

  Jim Lovelock entered the ozone story in the mid-1960s, when he became curious about the summer haze that he sometimes noticed spoiling the view from his country retreat. He couldn't remember seeing anything like that during his boyhood, and went off to visit some friends in the Meteorological Office to see whether they could explain it. Lovelock was thoroughly entertained that the U.K. Meteorological Office was officially part of the Ministry of Defense. He said, "We English have always been paranoid about the weather but this seemed too much. Did we now see it as a national resource and treasure that needed the army to protect it?" And he reacted just as merrily to the news that the U.S. Weather Bureau, by contrast, was in the Department of Commerce: "Perhaps they thought their weather was good enough to sell."

  Nobody at the Meteorological Office seemed to know what could be causing the haze, whether it was natural or had come from human hands. Then Lovelock had an idea. He knew all about Midgley's CFCs, which were now ubiquitous in English spray cans and refrigerators. They were inert, perfectly safe, and yet could perhaps be used as a "marker" for other, more unpleasant forms of industrial pollution. If there were higher levels of CFCs on the hazy days, that would suggest the haze was man-made.

  Lovelock decided to check, and he had just the instrument for the job. For like Midgley, Lovelock was a natural inventor. He made his first device—a wind gauge that he could hold out the windows of trains to measure their speed—at the age of ten, and he'd been inventing ever since. Lovelock made a good enough living from his creations to fund much of his science. But one machine was more important than most, and plays a vital role in the ozone story. Lovelock had invented a device that could detect tiny traces of many different chemicals, including CFCs. This is what he planned to use to try to determine the origin of the haze.