Life Stories

World-Renowned Scientists Reflect on their Lives and the Future of Life on Earth

Heather Newbold, editor

Ozone Hole
Sherwood Rowland

Although this story is in the third person, Sherwood Rowland wrote it himself. He used the third person because he prefers not to express himself in the first person in print. This is not as unusual as it seems: in professional publications, scientists avoid the first person and subjective observations.

"The work is going well, but it looks like it might be the end of the world."

Sherry Rowland said these words wearily to his wife after a long day researching the effects of chlorofluorocarbons at the University California, Irvine. Just a few years before, as chair, he had created the university's new chemistry department, and the challenge had gone well. But Rowland was also a research scientist. While his spelty was radiochemistry, he felt it was important to move on to nething new every few years. So he resigned the chair, returned to position as chemistry professor, and eventually began studying orofluorocarbons. In 1974, Rowland sounded the alarm that these called harmless chemicals were eating a huge hole in the ozone shield high in Earth's atmosphere.

Chlorofluorocarbons (compounds containing the three elements chlorine, fluorine, and carbon) had been developed in 1930 as a recement for sulfur dioxide and ammonia, refrigerants known to corrosive and toxic. They also smelled. In the old days, sulfur dioxide and ammonia were okay if they stayed in a refrigerator loop, but when that leaked they had an odor you didn't want in your kitchen.

In comparison, the CFCs, trademarked as Freons by the DuPont company, were considered safe, inert, and odorless. To prove their harmlessness, Thomas Midgley, the research engineer who developed CFCs, inhaled a lungful of CFC-12 and blew out a candle during a press conference.

In the beginning, CFC-II and CFC-12 went into refrigerators and air-conditioners. Later on, these chemicals were used in aerosol propellants and plastic foams and as solvents in the semiconductor industry. A huge amount, nearly a megaton a year, was being produced by 1973. Most of these CFCs were escaping into the air via aerosol sprays or leaking out from refrigerators and air-conditioners. But at the time no one was tracking their effects in the atmosphere.

In 1972, Rowland attended a meeting in Fort Lauderdale, Florida, at the invitation of William Marlowe, an Atomic Energy Commission (AEC) executive he had met on a trip to a scientific meeting in Austria in 1970. The AEC, seeking to stimulate more interaction between chemists and meteorologists, had started a series of joint workshops.

At the Fort Lauderdale meeting, Rowland heard a presentation that intrigued him. A colleague talked about the observations of James Lovelock, a British scientist who invented the electron-capture gas chromatograph. The instrument detected small amounts of trace gases in the atmosphere. Wherever Lovelock set up his chromatograph, CFC-II was present.

"We knew that the chlorofluorocarbons are simple molecules designed to be very nonreactive chemically. But even inert molecules can react under some conditions. My thought was, 'Let's see what we can find,' " explained Rowland of his initial decision to investigate chlorofluorocarbons. "Do we know enough about their chemical behavior to predict their fate in the atmosphere?"

The question was basically one of curiosity about how the world works. In retrospect, the main advance was to get out of the lab and into the real world by following a molecule from its release into the atmosphere to its eventual destruction many years later. No one had ever done that before with CFCs.

In 1973, Rowland approached the Atomic Energy Commission, which had funded his research since 1956, for additional support to study chlorofluorocarbons. At the same time, Mario Molina, a Mexcan chemist who had been educated in Europe and Mexico and had just completed his Ph.D. at Berkeley, arrived at Irvine to join the Rowland research group. Given a choice of research projects, Molina chose to look for the eventual fate of the CFCs.

Initially, there were no complicated experiments. Rowland and Molina pulled together information from other research. "In principle it was all there, but scattered all over—information about chemical behavior, industrial usage of CFCs, plus the chemistry and meteorology of the stratosphere," Rowland said of their findings. We used known information in the lab." But the questions they asked were key. How long did the CFC molecule last in the sphere? And what did it do there?

They found that the CFC molecule did not break up in a few days or even weeks; it lasted several decades or more, long enough to drift into the stratosphere, eight to thirty miles above Earth's surface. Some CFCs, they estimated, could last 150 years. On rising to the middle of the stratosphere, CFCs encounter ultraviolet radiation from the sun. This ultraviolet radiation can be absorbed by stratospheric ozone, and one of it penetrates to altitudes below fifteen miles. However, at altides of eighteen to twenty miles, the CFC molecules are split by the traviolet radiation, releasing chlorine atoms.

Rowland and Molina's next quest was to see what happened to the CFC fragments released by the ultraviolet radiation. Ozone formation and its destruction were naturally occurring processes that had always been balanced. Now, with CFC molecules breaking down and releasing chlorine atoms, a major source of chlorine had gathered in the upper atmosphere, throwing off that balance. Ozone was removed faster than by natural processes alone, and less remained. The one layer was thinning.

What troubled the researchers was that one chlorine atom destroyed one ozone molecule a minute, without itself being destroyed. What's more, the chlorine atom remained in the stratosphere for a year. Only when the chlorine diffused into the lower atmosphere did the cycle stop. Imagine the destruction with almost a megaton of chlorofluorocarbons being produced annually.

That's when Rowland made the comment to his wife, Joan. Without that protective ozone shield, life as we know it would change drastically. Radiation from the sun would increase, not only causing skin cancer and cataracts in humans but affecting animals as well, and precipitating changes in the human immune system that could make us sick.

In January 1974, Rowland and Molina sent a paper to the journal Nature, which did not appear until June because of personnel problems at the journal. Not until September, when the American Chemical Society had its semiannual meeting and held a press conference, did the press pick up on their discovery. Rowland and Molina predicted an eventual depletion of the ozone layer of 7 to 13 percent.

By that time, working with NASA support, Ralph Cicerone and Richard Stolarski, who had earlier worked out the stratospheric chlorine reaction, now confirmed that a chlorine chain reaction from the CFCs was occurring in the atmosphere.

It is tough to blow the whistle on a $2-billion-a-year industry, even when you are a well-respected chemist. Rowland and Molina's discoveries were based on research and chemical calculations that they felt without question to be correct. The National Academy of Sciences formed a five-member panel, which included Rowland, to decide whether the ozone problem was serious enough for a full-scale investigation.

But DuPont was a formidable company to be up against, and they were not going to give up their profitable product without a fight. They began mobilizing. One DuPont executive who visited Rowland told him he seemed to be an "environmental do-gooder."

"We said two important things about the CFCs," recalled Rowland of his research. "One, CFCs would last for a very long time, long enough to reach the stratosphere; and two, once there they would fall apart. But would they all really last for decades in the lower atmosphere? We wanted to test how rapidly they accumulated. You have to have measurements around the world, and we started doing that in 1977."

Rowland used a stainless-steel, two-liter canister with a valve through which all the air could be removed in the laboratory. Then he took the canister to a remote location, filled it with air, and headed back to the lab to measure the amounts of CFCs. "We needed a wide variety of latitudes and remote locations. At that time, we were not really funded to do this. So the collections were tacked onto other trips." If Rowland needed samples from Alaska, he arranged a stopover there on a scientific trip scheduled to Oregon. Or he flew to the West Indies on the way to a conference in Florida. That gave us enough of a geographical spread," he remembers of taking the samples. Fifteen years later, when Rowland's research was expanded, four thousand samples were taken in a two-month period from aircraft.

The next few years were a roller coaster of acceptance, legislation enforcing a ban, then skepticism, political indifference, and no regulation. In 1975 a government committee wrote a strong report suporting the prediction of a 7 percent ozone depletion. In 1976 there was thought to be a flaw in Rowland and Molina's theory—a frustrating, worrisome time. (Their original predictions held up.) In 1978 CFCs were banned in aerosol spray cans in the United States and three other countries, but their use was not banned at all in air-conditioners and refrigerators.

When the Rowlands' son was badly hurt in an auto accident in San Diego that same year, they moved there. Rowland worked as a hospital orderly to be near his son until he was well enough to come home. Except for the five months spent there, he persisted with the CFC issue.

What kind of childhood did Rowland have that lay the groundwork for this resolve? He grew up in Delaware, Ohio. His father was a math professor, and his mother had been a Latin teacher until her arriage. He started school at five, then skipped fourth grade, so that most students in his class were two and a half years older than he was. [When that happens, he remembers, "you live by yourself in some respects." His father gave him math problems often and Rowland found that numerical math came easily to him.

He grew up during World War II and liked to build model warships. He and other teenagers played a popular war game with their models, one that emphasized strategies. "The game was written about in Life magazine," he recalled. At fifteen, as a senior, he got permission to use the high school gym for a naval war battle with other students. It was a small town and a different time. That was also around the time Rowland experienced his growth spurt and became very athletic. He loved sports, and eventually he played semiprofessional base-ball, managed a team, and played basketball in college.

Apparently his early fascination with solving problems helped him with his research. In 1985 the seriousness of his findings on CFCs was supported yet again when the British Antarctic Survey published a report showing a 40 percent depletion of stratospheric ozone over Antarctica. Three expeditions were funded by the United States to Antarctica so that detailed measurements could be taken on the ground and from aircraft. In 1988 NASA reported not only that the Antarctic ozone loss was caused by chlorofluorocarbons but also that ozone loss could be seen at all latitudes, including over the United States.

The Montreal Protocol on Substances That Deplete the Ozone Layer, a United Nations agreement designed to reduce CFC consumption by 50 percent by 1999, was signed by twenty-four nations in 1987. DuPont announced it would phase out the production of CFCs the following year.

With all the ups and downs, Rowland remained calm and persistent, even when President Reagan's first Environmental Protection Agency chief referred to Rowland's work as a scare tactic. The one time he got angry was when a well-known news show asked him to talk about CFCs right after DuPont announced it would stop CFC manufacture. Rowland agreed to do the show. The news show producers then contacted DuPont and asked if a company representative would appear with Rowland. DuPont would only appear, said a company spokesperson, without Rowland. Rowland was bounced.

In 1995, Rowland and Molina were awarded a Nobel Prize for their discovery that chlorofluorocarbon gases were depleting the ozone layer in the stratosphere. Rowland was typically low-key about the honor. (Rumor has it that the morning the Swedish committee called when tell him he was a Nobel Prize winner, he did get excited.)

In spite of all the scientific facts, satellite photos, and the affirmation on of the Nobel Prize, disbelief still exists that ozone depletion is caused by CFCs and that it is a serious problem. "Many people just believe what they want to believe. Nevertheless, anyone can now follow on the Internet the startling loss of ozone that occurs over Antarctica every September. It hasn't stopped," he says simply. And Rowland, still at work, hasn't stopped his research.