Richard Benedick, Negotiator of Landmark Ozone Treaty, Dies at 88

A May 1985 report in the journal Nature was alarming. High above Antarctica, a massive hole had opened in the ozone shield that protects life on earth from the sun’s ultraviolet rays.

The finding confirmed what scientists had warned of since the 1970s: Atmospheric ozone was being broken down by the wide use of chlorofluorocarbons, chemicals known as CFCs, which were found in aerosol sprays, refrigeration and air conditioning.

Just over two years later, dozens of nations meeting in Montreal signed an agreement to significantly reduce CFCs, which the Environmental Protection Agency estimated would prevent 27 million deaths from skin cancers.

“This is perhaps the most historically significant international environmental agreement,” Richard E. Benedick, the chief United States negotiator, said at the time.

Ever since, the Montreal Protocol, as the pact is known, has stood as a milestone of collective action in the face of a planetary environmental threat, as well as a rebuke of the lack of international resolve to tackle the more dire and complex threat of climate change.

Mr. Benedick, who was a career diplomat in the State Department when the Montreal Protocol was signed in 1987, and who patiently wore down opposition from foreign nations while withstanding powerful internal critics in the Reagan administration, died on March 16 in Falls Church, Va. He was 88.