Forty years ago this week, Arab oil producing countries imposed an oil embargo on the U.S., to punish it for supporting Israel during the Yom Kippur War. The result was an economic shock so profound it changed America’s view of its position in the world. But the 1973 oil embargo may have also yielded some unexpected benefits.

“One of the legacies,” says Joel Darmstadter, a senior fellow at the NGO Resources for the Future, where he started working close to the period of the oil embargo, “is the fact that there are people my age who remember waiting in gas lines for an hour and a half in the winter of ’73-’74.”

Oil prices nearly quadrupled, to about $57 a barrel in today’s dollars. Darmstadter says energy independence took on a new urgency.

President Nixon created a 55 mile per hour speed limit, to save fuel. Then came the first CAFE standards for fuel economy. Money for energy research increased; some of those projects paid off, others didn’t. Still, UCLA professor Michael Ross says the embargo changed the course of conservation.

“If we had never experienced the 1973 oil shock, carbon emissions might be far higher today,” he says, “And we would be in an even worse situation with respect to climate change.”