Which would have the bigger impact: encouraging more car-pooling, or the reduced car emissions from electric vehicles? Although the book only looks at ride-sha

Which would have the bigger impact: encouraging more car-pooling, or the reduced car emissions from electric vehicles? Although the book only looks at ride-sharing in the United States and Canada, it presumes pretty modest gains, so the benefits of car-pooling don’t even come close to the emissions savings from electric cars. With the benefit of hindsight the question is more clearly phrased as: "Which would have the bigger impact: simply asking people to do more car-pooling, or actually making the switch to electric vehicles from ICE vehicles?" The question sneakily turns out to be about what's (assumed) easier to get people to do, not which action, undertaken on equal scale, has greater benefits. (But then why are wind farms preferred over solar on a later question, considering how much more frequently NIMBY opposition arises toward wind farms?)