Despite plummeting sales and public opposition to nuclear power, the head of a major German industrial conglomerate says that atomic energy is the only alternative to fuels which cause global-warming emissions. Renewables such wind and solar are not yet ready to replace nuclear plants economically, said Heinrich von Pierer, chief executive of Siemens AG, in early June at a celebration of the company's 150th birthday in Munich. He also said the company has no plans to leave the nuclear business in the foreseeable future, despite opposition to the technology in Germany. "If someone at the end of the 20th century wants to talk about an alternative source of energy, then that can only mean atomic energy," he insisted. The world's increasing population is raising demand for energy. And atomic energy does not produce carbon dioxide emissions that are suspected of raising temperatures in the atmosphere, he said. Even so, in the first half of 1996/97, sales at Siemens' power generation unit fell 28% while orders fell by one-fifth.