F. Sherwood Rowland (1927–2012) Atmospheric Chemist Who Linked Human Activity to Ozone Depletion

COMMENT OBITUARY F. Sherwood Rowland (1927–2012) Atmospheric chemist who linked human activity to ozone depletion.

hlorofluorocarbons (CFCs) were a trace gases and on one-dimensional models interests in ozone and environmental policy, triumph of the chemical industry that could now easily run on a smart phone. but his research moved on. Soon after the and a mere curiosity in atmospheric Nonetheless, the pair measured the ultra- ozone hole was discovered over Antarctica, Cscience when Sherwood (Sherry) Rowland, violet cross sections of CFC-11 and -12 in he made major contributions with his gradu- with his postdoc Mario Molina, recognized the lab, calculated their photolytic destruc- ate student Neil Harris to the detection of in 1973 that these seemingly inert gases tion rates in the atmosphere and derived ozone depletion over the Northern Hemi- posed a threat to Earth’s ozone layer. Return- their atmospheric lifetimes as 50–100 years. sphere. This work was crucial in persuading ing home one evening, Rowland remarked to They reviewed industrial production and DuPont and other chemical companies to his wife Joan that the research “is going very emission of CFCs, projected the build-up abandon CFCs in favour of hydrochloro- well, but it may mean the end of the world”. and release of chlorine atoms in the strato- fluorocarbons, which are less damaging to In their laboratory at the University of sphere and concluded that ozone depletion the ozone layer. California, Irvine, Molina and Rowland In the late 1970s, Rowland initiated a had discovered that CFC-11 (CFCl3) and programme to monitor background concen- CFC-12 (CF2Cl2), then widely used as trations of various gases, and that continues refrigerants and aerosol propellants, readily today. Six of its group members were work- absorbed ultraviolet light and broke down to ing in the field when he passed away. His release reactive chlorine. This work was the curiosity demanded an objective approach, C. PUMA/UC IRVINE first step in tracing the causal chain linking and so it was when, working with his former industrial production of CFCs with global student and then fellow professor (D.R.B.), ozone depletion — and won Rowland and he identified in 1995 that the unusual mix Molina the 1995 Nobel Prize in Chemistry, of high ozone and hydrocarbons in Mexico shared with Dutch chemist Paul Crutzen. City was due to leaking propane stoves and Surrounded by his family at his home in heaters, rather than traffic. In 2011, he was Corona del Mar, California, Rowland died involved in discussions regarding the mix of on 10 March, aged 84, from complications of atmospheric hydrocarbons resulting from Parkinson’s disease. He was born in Delaware, the Deepwater Horizon oil spill in the Gulf Ohio; his mother was a Latin teacher and his of Mexico. father taught mathematics at Ohio Wesleyan Over almost five decades, Rowland was University in Delaware, where Rowland active in his research lab as well as teaching, attended college after graduating from high playing tennis and having collegial discus- school at 15. When he was old enough, he sions over lunch. When not travelling, he enlisted in the US Navy. As a lanky athlete, he could be seen carrying his briefcase in one readily found a home in sports teams in the hand, with a pile of papers under the other Navy and later in graduate school at the Uni- was likely and would be long-lived, even with arm, to and from his office. He was a prolific versity of Chicago, Illinois, where he played remediation. This work has been borne out, note-taker, filling a notebook in a week. This baseball for the university and for a semi- in detail, by nearly four decades of research. practice intimidated one of us (M.J.P.), who, professional team. Rowland and Molina’s work started an while giving a talk at an international con- Rowland earned his PhD in nuclear chem- environmental movement that began with ference, first encountered Sherry in the front istry at Chicago under chemist Willard Libby scientists, led by Rowland, urging the elimi- row, taking assiduous notes and then asking a and was taught by four other faculty mem- nation of CFCs. It remains the best success terrifying, brutal, yet constructive question. bers; counting Sherry, all six would later story for global cooperation on a worldwide Rowland treated everyone like a colleague. receive Nobel prizes. He met Joan at Chicago, environmental threat. The activism led He disarmingly considered questions from and they moved to take up his early jobs at to the 1978 ban by the US Environmental any listener with the depth and profundity Princeton University in New Jersey and at the Protection Agency on CFC use in aerosol due a scientific peer. This trait was appre- University of Kansas in Lawrence. In 1964, cans, and finally in 1990 to the complete ciated by students, friends and family. To Rowland accepted an offer to start up the phasing out of CFC production by the Sherry, the question was of foremost impor- chemistry department at a new University of Montreal Protocol and its amendments. tance; it was at the core of his scientific quest. California campus in the then-unbuilt city In his unwillingness to back down from the His passing ended a unique career that of Irvine. Later, with atmospheric chemist implications of his work, Rowland became a merged chemistry and atmospheric sciences, Ralph Cicerone, he also helped to found the role model to many of us, and remains so. leading to a new partnership between science Earth system science department. This was a threat to some — particularly the and policy for the protection of our planet. ■ The elegance of Molina and Rowland’s CFC industry, but also, less understandably, 1974 Nature paper remains impressive to to some scientific colleagues. For many years, Michael J. Prather is Fred Kavli Chair in today’s atmospheric chemists, who live in a Rowland experienced personal threats as well Earth system science and Donald R. Blake world of satellite observations and supercom- as irrational attacks on the science. is professor of chemistry at the University of puters. Stratospheric chemistry at the time Rowland’s science always stood tall, as California, Irvine, California, USA. was based on balloon-borne samplers of did he, and seemed inerrant. He kept up his e-mail: [email protected]