Ralph J. Cicerone, the fourth chancellor of UC Irvine, a world-renowned atmospheric scientist and former president of the National Academy of Sciences, died Saturday, the university reported.

Cicerone was 73 and died at his home in New Jersey, the academy said in a statement.

Credited with helping shape science and environmental policy nationally and internationally, Cicerone came to UCI in 1989. He helped found the school’s Department of Earth System Science and became dean of the School of Physical Sciences.

“Ralph played a central role in moving the School of Physical Sciences and UCI to a premier position as a top research university,” said Kenneth C. Janda, physical sciences dean. “His design for the Earth system science department was unique and well ahead of its time, bringing together top scientists from engineering, physics and chemistry to study a problem of crucial importance to humanity: climate change.”

Born in western Pennsylvania to an insurance salesman father and a homemaker mother, Cicerone attended the Massachusetts Institute of Technology on an athletic scholarship. He received a bachelor’s degree from MIT, where he played varsity baseball, and master’s and doctoral degrees in electrical engineering from the University of Illinois at Urbana-Champaign.

Early in his career, Cicerone was a research scientist and faculty member at the University of Michigan and a research chemist at the Scripps Institution of Oceanography. Just before joining UCI, he was a scientist at the National Center for Atmospheric Research. He also did stints at the Department of Commerce and UC San Diego.

As a researcher, he frequently testified before congressional committees about climate-change policy. He is a recipient of the Bower Award & Prize for Achievement in Science from the Franklin Institute and was recognized on a 1995 citation for the Nobel Prize in chemistry.

“For his courageous work uncovering the causes and effects of climate change, the world owes him a debt of gratitude,” UCI Chancellor Howard Gillman said in a statement.

Cicerone helped create the $500 million Gulf Research Program to enhance oil system safety after the 2010 Deepwater Horizon disaster, in which millions of gallons of oil spilled into the Gulf of Mexico and 11 oil crewmen died after a blowout and explosions.

He also established several studies that helped define the causes, extent and effect of global climate change.

In frequent meetings with members of Congress and heads of federal agencies, he spoke out on the importance of science education.

“Crucial political decisions about scientific matters, involving subjects such as the environment, cannot be judged by voters who have no understanding of what constitutes scientific evidence or the scientific method,” he told the Register in a 2003 interview. “Study after study has shown that we have a scientifically illiterate public – one that doesn’t understand the nature of risk, the meaning of statistics or even why summer is hotter than winter.”

Cicerone was named chancellor in 1998, and during his tenure UCI climbed the national rankings, adopted a more selective admissions process, increased private funding, began construction on a new learning hospital at the UCI Medical Center and revived the school’s baseball program.

“We have to make sure not only that we have access for more people than at private universities, but we have to be just as good or better,” he said. “It’s fundamental to the running of a democracy that the best public universities are at least as good as the best private universities.”

In 2009, Cicerone Field at Anteater Ballpark was named in his honor.

Cicerone left UCI in 2005 to serve as the 21st president of the National Academy of Sciences, to which he was elected in 1990. Election to the academy is considered one of highest honors bestowed to U.S. scientists.

“I couldn’t turn it down,” he told the Register at the time.

He ended his second and final term as president in June.

“The entire scientific community is mourning the sudden and untimely loss of this great leader who has been unexpectedly removed from the forefront of the scientific issues that matter most to the future well-being of society,” Marcia McNutt, Cicerone’s successor as president of the National Academy of Sciences, said in a statement Saturday. “Ralph Cicerone was a model for all of us of not only doing what counts, but doing it with honesty, integrity, and deep passion.”

Cicerone is survived by his wife, Carol, a UCI professor of cognitive sciences, a daughter and two grandchildren.

Contact the writer: 714-796-2478 or lcasiano@scng.com