Twenty years ago, John S. Hoffman, a 14-year veteran of the Environmental Protection Agency, launched a deceptively simple program to address a problem that he, but not too many others, worried about incessantly: global warming. The program was called Energy Star. It ended up saving $230 billion in electrical bills and 1.7 billion metric tons in carbon emissions in the United States alone. Hoffman, whose death in late September at 62 was reported this week, proved just how much one government employee can do.

Hoffman began devising the Energy Star program after calculating the waste of electricity by office computers left on all night and all weekend. His common-sense solution — pushing offices to turn off their hardware, and encouraging computer companies to incorporate energy-saving technology — marked “a completely different way of approaching environmental problems,” he declared in 1991.