> Midgley's legacy has been scarred by the negative environmental impact of leaded gasoline and Freon. Environmental historian J. R. McNeill opined that Midgley "had more impact on the atmosphere than any other single organism in Earth's history", and Bill Bryson remarked that Midgley possessed "an instinct for the regrettable that was almost uncanny".
Multiple sources seem to agree that the reason he chose to add lead to gasoline rather than ethanol (which was both greener and cheaper) was due to profit: his company could patent leaded gasoline, but not ethanol. That's an interesting lesson that we should learn any day now.