Mexican atmospheric chemist Mario J. Molina (full name, José Mario Molina-Pasquel Henríquez [1943-]) and American atmospheric chemist Frank Sherwood Rowland (1927–) are generally acknowledged as the scientists who first explained how chlorofluorocarbons were destroying the ozone layer. A paper they published together in 1974 first explained how the process works about four years after scientists began to understand that ozone levels were declining in the upper atmosphere. The result of their work led the United States government to ban CFCs in aerosol cans in 1978.