“It was going to be a civilization that made oil strategically obsolete.”… The first thing the students noticed was not the silence, but the smell. Professor Senda always kept the laboratory windows open, even during Osaka’s wet June heat. Usually the air carried the scent of solder, machine oil, and old coffee. But that morning in 2043, another odor drifted in from the port district—a faint sweetness mixed with burned plastic. “The ammonia carriers are unloading again,” one student muttered. Senda nodded without looking up from the wall display. “Green ammonia from Western Australia. Produced entirely from offshore wind and high-temperature electrolysis. Twenty years ago people said it was impossible to transport energy that way economically.” Outside the university tower, the skyline had changed. The rooftops were darker now, layered with perovskite solar films that glimmered like oil on water. Autonomous cargo trams moved silently below. Even the convenienc...