Rowland, F. Sherwood (1927- )

views updated Jun 08 2018

Rowland, F. Sherwood (1927- )

American atmospheric chemist

In 1974, F. Sherwood Rowland and his research associate, Mario Molina , first sounded the alarm about the harmful effects of chlorofluorocarbons, or CFCs, on the earth's ozone layer. CFCs, which have been used in air conditioners, refrigerators, and aerosol sprays, release chlorine atoms into the upper atmosphere when the sun's ultraviolet light hits them. The chlorine then breaks down atmospheric ozone molecules, destroying a shield that protects the earth from damaging ultraviolet rays . In the mid–1980s, a National Aeronautics and Space Administration (NASA) satellite actually confirmed the existence of a continent-sized hole in the ozone layer over Antarctica . By the early 1990s, National Oceanographic and Atmospheric Administration (NOAA) scientists warned that yet another ozone hole, this one over the Arctic, could imperil Canada, Russia, Europe , and, in the United States, New England. This news might have been gratifying affirmation for Rowland, a professor of chemistry at the University of California at Irvine, but rather than rest on his laurels he continued to steadfastly and soberly warn the world of the ozone danger. His efforts have won him worldwide renown and prestigious awards, including the Charles A. Dana Award for Pioneering Achievement in Health in 1987, the Peter Debye Award of the American Chemical Society in 1993, the Roger Revelle Medal from the American Geophysical Union for 1994, and the Japan Prize in Environmental Science and Technology, presented to Rowland by the Japanese emperor in 1989.

Frank Sherwood Rowland was born in Delaware, Ohio, the son of a math professor, Sidney A. Rowland, and his wife, Latin teacher Margaret Drake Rowland. In an interview with Joan Oleck, Rowland claimed that math always came easy for him. "I always liked solving puzzles and problems," he said. "I think the rule we had in our family that applied even to my own children was you had your choice in school as to what order you took biology, chemistry, and physics , but not whether."

Sidetracked by World War II, Rowland was still in boot camp when peace arrived. In 1948, he received his B.A. degree from Ohio Wesleyan University; after three years—the summers of which he spent playing semiprofessional baseball—he obtained his master's from the University of Chicago. His Ph.D. came a year later, in 1952. That same year he married Joan E. Lundberg; the couple would eventually have a son and daughter.

Also in 1952, Rowland obtained his first academic job, an instructorship in chemistry at Princeton University, where he would remain for four years. In 1956, Rowland moved his family west to the University of Kansas, where he was a professor for eight years, and then farther west still, to Irvine, California, where he took over as chemistry department chairman at the University of California in Irvine in 1964. He has stayed at Irvine ever since, enjoying stints as Daniel G. Aldrich, Jr., Professor of Chemistry from 1985 to 1989, and as Donald Bren Professor of Chemistry since 1989.

At Chicago, Rowland's mentor had been Willard F. Libby , winner of the Nobel Prize for his invention of carbon–14 dating, a way to determine the age of an object by measuring how much of a radioactive form of carbon it contains. The radioactivity research Rowland conducted with Libby led the young scientist eventually to atmospheric chemistry . Realizing, as he told Oleck, that "if you're going to be a professional scientist, one of the things you're going to do is stay out ahead of the pack," Rowland looked for new avenues to explore. In the 1970s, Rowland was inspired by his daughter's dedication to the then-fledgling environmental movement and by the tenor of the times: 1970 was the year of the first Earth Day. In 1971, the chemist helped allay fears about high levels of mercury in swordfish and tuna by showing that preserved museum fish from a hundred years earlier contained about the same amount of the element as modern fish.

Later events pushed him further in the direction of environmental concerns. At a meeting in Salzburg, Austria, Rowland met an Atomic Energy Commission (AEC) staffer who was trying to get chemists and meteorologists into closer partnerships. Sharing a train compartment with the AEC man to Vienna, Rowland was invited to another professional meeting. And it was there, in 1972, that he first began to think about chlorofluorocarbons in the atmosphere.

In those days, production of CFCs for household and industrial propellants was doubling every five years. A million tons of CFCs were being produced each year alone, but scientists were not particularly alarmed; it was believed they were inert in the atmosphere. Rowland, however, wanted to know more about their ultimate fate. Ozone, a form of oxygen , helps make up the stratosphere , the atmospheric layer located between eight and 30 miles above the earth. Ozone screens out dangerous ultraviolet rays, which have been linked to skin cancer, malfunctions in the immune system, and eye problems such as cataracts. Performing lab experiments with Molina, Rowland reported in 1974 that the same chemical stability that makes CFCs useful also allows them to drift up to the stratosphere intact. Once they rise thorough the ozone shield, Rowland and Molina warned, they pose a significant threat to ozone: each chlorine atom released when CFCs meet ultraviolet light can destroy up to one hundred thousand ozone molecules.

Sounding the alarm in the journal Nature in June of 1974 and in a subsequent presentation to the American Chemical Society that September, Rowland attracted attention: a federal task force found reason for serious concern; the National Academy of Sciences (NAS) confirmed the scientists' findings; and by 1978, the Environmental Protection Agency (EPA) had banned nearly all uses of CFC propellants. There were setbacks: In the 1980s President Ronald Reagan's EPA administrator, Anne Gorsuch, dismissed ozone depletion as a scare tactic. And Rowland himself discovered that the whole matter was more complex than originally thought, that another chemical reaction in the air was affecting calculations of ozone loss. The NAS's assessment of the problem was similarly vague, generalizing future global ozone losses as somewhere between 2%–20%.

Then came a startling revelation. In the mid–1980s a hole in the ozone shield over Antarctica the size of a continent was discovered; NASA satellite photos confirmed it in 1985. The fall in ozone levels in the area was drastic, as high as 67%. These events led to increased concern by the international community. In 1987 the United States and other CFC producers signed the Montreal Protocol, pledging to cut production by 50% by the end of the millennium. Later, in the United States, President George Bush announced a U.S. plan to speed up the timetable to 1995.

There were more accelerations to come: Du Pont, a major producer, announced plans to end its CFC production by late 1994, and the European Community set a 1996 deadline. And producers of automobile air-conditioning and seat cushions—two industries still using CFCs—began looking for alternatives. These goals only became more urgent in the face of the 1992 discovery of another potential ozone hole, this one over the Arctic. Scientists have attributed the extreme depletion of ozone over the poles to weather patterns and seasonal sun that promote an unusually rapid cycle of chlorine-ozone chain reactions.

In addition to the development of holes in the ozone layer, the atmosphere is further threatened because of the time delay before CFCs reach the stratosphere. Even after a complete ban on CFC production is achieved, CFCs would continue to rise through the atmosphere, and were predicted to reach peak concentrations in the late 1990s. Some remained skeptical of the dangers, however. In the early 1990s a kind of "ozone backlash" occurred, with a scientist as prominent as Nobel Prize-winning chemist Derek Barton joining those who called for a repeal of the CFC phase-out pact.

Meanwhile Rowland continued his examination of the atmosphere. Every three months, his assistants have fanned out around the Pacific Ocean to collect air samples from New Zealand to Alaska. The news from his research has been sobering, turning up airborne compounds that originated from the burning of rain forests in Brazil and the aerial pollution of oil fields in the Caucasus mountains. "The major atmospheric problems readily cross all national boundaries and therefore can affect everyone's security," Rowland said in his President's Lecture before the American Association for the Advancement of Science (AAAS) in 1993. "You can no longer depend upon the 12-mi (19.3-km) offshore limit when the problem is being carried by the winds." An instructive reminder of the international nature of such insecurity was given by the arrival only two weeks later in Irvine, California, of trace amounts of the radioactive fission products released by the 1986 Chernobyl nuclear reactor accident in the former Soviet Union.

Rowland has said in interviews that he's pleased with the progress he's helped set in motion. "One of the messages is that it is possible for mankind to influence his environment negatively," Rowland told Oleck. "On the other side there's the recognition on an international basis that we can act in unison. We have the [Montreal] agreement, people are following it, and it's not only that they have said they will do these things but they are doing them because the measurements in the atmosphere show it. People have worked together to solve the problem."

See also Atmospheric circulation; Atmospheric composition and structure; Atmospheric pollution; Ozone layer and hole dynamics

World of Earth Science

Rowland, Frank Sherwood (1927 – ) American Atmospheric Chemist

views updated May 14 2018

Frank Sherwood Rowland (1927 – )
American atmospheric chemist

Rowland was born in the central Ohio city of Delaware. After a brief period of service in the United States Navy, he attended Ohio Wesleyan University where he earned his bachelor's degree in chemistry in 1948. He balanced his semi-professional baseball career with his studies and continued his education in chemistry, earning master's and doctorate degrees at the University of Chicago in 1951 and 1952, respectively. Fresh out of school, Rowland pursued a career in education and research. He taught chemistry at Princeton University from 1952 to 1956 and the University of Kansas between 1963 and 1964.

Rowland has conducted research in many areas of the chemical and radiochemical fields. In 1971, for example, to calm an alarmed public, Rowland and a team of scientists investigated the seemingly high levels of mercury being found in tuna and swordfish . They tested the tissues of museum exhibit, century-old fish and found the levels of the dangerous substance were in about the same range as those recently pulled from the water, and therefore proved the fish were not a health threat. In addition to this type of testing, he completed work for such organizations as the International Atomic Energy Administration and the United States Atomic Energy Commission . Rowland is probably best known, however, for his work in atmospheric and chemical kinetics and especially his investigations of chlorofluorocarbons (CFCs).

Inert and versatile compounds, CFCs were most often found in items like cooling devices and aerosol cans; CFCs are also found throughout the atmosphere . The inherent dangers of CFCs were unknown until Rowland teamed up with University of California associate Mario Molina in 1973 and found that certain atoms of those CFCs present in the atmosphere were combining with the ozone , causing rapid depletion of the protective ozone layer itself. Such destruction could result in drastic climatic changes, as well as increased atmospheric penetration by the sun's rays (causing a huge upswing of the occurrence of skin cancer ).

Initially, Rowland's and Molina's theory was not readily accepted. In recent years however, the theory has come be accepted as an unpleasant fact; the importance of CFC elimination has been realized. Major industries are taking steps to address the CFC problem. Du Pont for example, a major developer and manufacturer of CFCs, has pledged to reduce its production of the compounds. The 1995 Nobel Prize in chemistry was awarded to Rowland, Molina, and Paul Crutzen.

Rowland is currently the chemistry department chairman at the University of California at Irvine, where he has been a faculty member since 1964. He maintains membership in numerous organizations, among them: the Ozone Commission of the International Association of Meteorological and Atmospheric Physics; Committee of Atmospheric Chemical and Global Pollution ; and various committees of the United States National Academy of Science.

[Kimberley A. Peterson ]