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The Royal Swedish Academy of Sciences has awarded its 1995 Nobel prizes in chemistry to three AGU members for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone. Only one other Nobel prize has ever been warded in the realm of atmospheric research. The honorees are professors Paul Crutzen of the Max-Planck Institute for Chemistry in Mainz, Germany; Mario Molina of the Massachusetts Institute of Technology; and F. Sherwood Rowland of the University of California, Irvine. The Academy credits the three with contributing to "our salvation from a global environmental problem that could have catastrophic consequences."
Crutzen, Molina, and Rowland are noted for their pioneering contributions to explaining how ozone forms and decomposes through chemical processes in the atmosphere. They have shown how sensitive the ozone layer is to the influence of anthropogenic emissions of certain compounds. The thin ozone layer has proven to be an "Achilles heel" that may be seriously damaged by moderate changes n the composition of the atmosphere. The work of these pioneers contributed in 1987 to the signing of the Montreal Protocol, a multinational accord that severely limited CFC emissions to protect the ozone layer. With a few exceptions, the gases that pose the greatest threat to the ozone layer will be completely banned by 1996. If the protocol guidelines are followed, it will take at least 100 years for the ozone layer to recover.
In 1930, English physicist Sidney Chapman developed the first
photochemical theory for the formation and decomposition of ozone
in the atmosphere. In 1970, Crutzen took the first fundamental step
toward a deeper understanding of the chemistry of the ozone layer.
He showed that the nitrogen oxides NO and NO2
The next leap in knowledge of ozone chemistry was taken in 1974, when Molina and Rowland published their widely noted Nature article on the threat to the ozone layer from chlorofluorocarbon (CFC) gases known as "freons." These gases were being used in spray bottles, as the cooling medium in refrigerators and air conditioners, and in plastic foams. The two scientists realized that CFCs, which are chemically stable, could gradually be transported through normal air circulations to the stratosphere. There, intense ultraviolet light could break up the molecules, releasing chlorine, which catalyzes ozone destruction. Although controversial at first, the Molina-Rowland hypothesis was strengthened in 1985 when a drastic seasonal depletion of stratospheric ozone over the Antarctic, the ozone hole, was discovered. The work of Molina and Rowland built upon important contributions from other researchers, including James Lovelock, Richard Stolarski, and Ralph Cicerone.
The award is being hailed as a great recognition for atmospheric
science as a whole. National Center for Atmospheric Research
atmospheric chemist Jack Calvert, who worked with all three Nobel
recipients, said,
Crutzen, Molina, and Rowland are members of AGU, Crutzen and Rowland being AGU Fellows. Crutzen received his doctorate in meteorology from Stockholm University in 1973. He is a member of the Royal Swedish Academy of Sciences, the Royal Swedish Academy of Engineering Sciences, and Academia Europaea. Molina received his doctorate in physical chemistry from the University of California, Berkeley. He is a member of the U.S. National Academy of Sciences. Rowland received his doctorate in chemistry from the University of Chicago. He is a member of the American Academy of Arts and Sciences and the U.S. National Academy of Sciences, where he is currently foreign secretary. He was awarded AGU's Roger Revelle medal in 1994.