Between 1945 and 1960, Japan had some of the most energy-efficient iron and steel industries in the world. Two technologies-heat management and oxygen steelmaking-were key enablers of significant energy conservation, an industrial success story commonly attributed to Japan's post-World War II development. Contrary to current understanding, both technologies had deep pre-World War II roots. Their development accelerated after the war through institutionalized exchanges of experience and expertise among Japanese companies. However, these energy conservation technologies had unintended and little-known consequences: they were a major source of air pollution. This article provides two correctives. First, energy conservation technologies took longer to develop than previously thought. Second, saving energy can dramatically increase an industry's environmental footprint. Japan's industrial experience provides an example of how the road to air pollution hell was paved with the best energy conservation intentions.

• Schlagwörter
  Luftverschmutzung, Energieeinsparung, Brennstoff, Japan, Eisen- und Stahlindustrie, Geschichte 1945-1960