Mario Molina, Chlorofluorocarbons (CFCs), and Ozone Depletion

Resources with Additional Information

In 1973 Mario Molina … was a postdoctoral researcher working in the laboratory of F. Sherwood Rowland at the University of California at Irvine ... when he made an unsettling discovery. He had been investigating a class of compounds called chlorofluorocarbons, or CFCs. CFCs were used as refrigerants, aerosol sprays, and in making plastic foams. Molina wondered what happened to them once they were released into the atmosphere. …

Mario Molina
Centro Mario Molina

[Molina’s] results suggested that CFCs could, in theory, destroy an oxygen compound called ozone under the conditions that exist in the upper atmosphere. … [He] was nervous about showing Rowland his theory of how CFCs might destroy ozone. But if CFCs really could reduce ozone at a predicted rate of 7 percent after 60 years, the world would be in trouble. …

Rowland took his protégé seriously. Over the next two decades he and Molina became voices alerting the world to the danger of CFCs and ozone depletion. They were not always heeded. Bans on CFCs in aerosol sprays went into effect first in the United States in 1978, and later in Canada, Norway, and Sweden. …

Over the years evidence mounted in support of Molina’s theories, leading to increased international regulation of CFCs. But this did not happen easily, nor did it happen overnight. Before most of the world would listen, it took an alarming observation in 1983 by British scientist Joseph Farman and colleagues that the ozone levels above Antarctica had been dropping dramatically, by as much as 35 percent, during the Antarctic spring (September through December) compared with 1960s levels. …

Molina and Rowland were vindicated. In 1987 the Montreal Protocol for reducing named substances that deplete the ozone layer was opened for signature. By 2009 all nations in the United Nations had ratified the original protocol. In 1995 Molina and Rowland were awarded the Nobel Prize for chemistry, along with Swedish scientist Paul Crutzen, for the work they had done in helping unravel the mysteries and dangers of CFCs.

– Edited excerpt from Mario Molina and Susan Solomon, Chemical Heritage Foundation (CHF)

Resources with Additional Information

Additional information about Mario Molina, chlorofluorocarbons (CFCs), and ozone depletion is available in electronic documents and on the Web.



Additional Web Pages:

Mario J. Molina, Chemistry, 1995, University of California San Diego (UCSD)

Molina Wins Nobel Prize for Ozone Work, Massachusetts Institute of Technology (MIT)

Putting the Pieces Together, University of California Berkeley

Molina Reflects on Prize-winning Research, Massachusetts Institute of Technology (MIT)

Interview with Mario J. Molina, (video)

Nobel Prize-winning Chemist Joins UCSD Faculty, University of California San Diego (UCSD)

Mario Molina, UCSD Faculty

Scripps Chemistry Professor Named as Member of IPCC Review Committee, Scripps Institution of Oceanography, UC San Diego


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