No eureka moment led Chu to decide to confront climate change so directly. "This actually came gradually," he says. "Maybe six or seven years ago, I got concerned about the energy problem. As I started to read more and more, I came to realize this could be really serious." At the time, he was still a professor at Stanford. At physics conferences, in addition to his laser-cooling talks, he began to offer a lecture on energy. He joined the board of the Hewlett Foundation, a nonprofit organization that was deeply involved in environmental issues, and he met many "like-minded souls," he says. In 2004, his former boss back at Bell, then head of Lawrence Berkeley, was moving on and urged Chu to at least interview for the position. It may have seemed like a leap, but the duties at Lawrence Berkeley would really be a shift in scale and not in type from his job at Bell. "My first answer was no," Chu says. "I didn't have aspirations to be a big bureaucrat." But soon he had second thoughts. "If I really was interested in doing something about climate change, this would be a good platform. If I could get some of the best scientists to Lawrence Berkeley and get them to shift their interest, it might have some impact." Lawrence Berkeley offered him the job the afternoon he interviewed.