Energy and environment; The light path

This paper reports that for 200 years, the world has progressively lightened its energy diet by favoring hydrogen atoms over carbon in our hydrocarbon stew. The successful decarbonization of the energy system, the key to the alleviation of numerous environmental problems, will ultimately depend on the use of pure hydrogen fuel produced form sources and processes that are carbon-free. The outlook for aggregate reductions in the materials that an individual consumes, dematerialization, is less certain. Rapid evolution of the energy system along its current trajectory, combined with cultural change, can avert the environmental danger.danger.