Arthur H. Rosenfeld, a physicist who became widely known as the father or energy  efficiency for championing energy-saving requirements for appliances and buildings, died on Friday in Berkeley, Calif. He was 90.

The cause was related to pneumonia, said Adam Gottlieb, a marketing and outreach specialist with the California Energy Commission, with which Dr. Rosenfeld worked for 10 years.

His work, embraced at first in California under Gov. Jerry Brown, gained national attention and helped lay the foundation for federal energy efficiency rules that are in place today.

Read more (The New York Times)