Frederick Seitz, a highly honored physicist who led both the National Academy of Sciences and Rockefeller University and was an outspoken skeptic of global warming, died on Sunday at a nursing home in New York City. He was 96. The cause of death was not reported in obituaries, which appeared in The New York Times, The Washington Post, and other newspapers today.

Mr. Seitz was president of the National Academy of Sciences from 1962 to 1969, and was appointed president of Rockefeller University in 1968, a position he held until 1978. In 1973, President Richard M. Nixon presented him with the National Medal of Science for his contributions to the modern quantum theory of the solid state of matter.

Frank Press, a successor to Mr. Seitz as president of the National Academy, described Mr. Seitz to the Times as “a pioneer in the field of condensed-matter physics.” He was the author of an influential text on the development of solid-state physics and of transistors, and numerous other books.

Late in life he became known for his contrarian views on global warming. In 1998 he solicited thousands of scientists to sign an eight-page petition against the Kyoto protocol on global warming. —Charles Huckabee