They say necessity of the mother of invention and while it certainly plays a role in most good creations, there are others inventions that must have been borne from madness, arogance or just plain stupidity. TopTenz has compiled an excellent list of just such creations ranging from the car spittoon (above) to a Razr phone that is actually equipped with a working electric razor.
Of course, not everything that seems to be an immediate failure is actually worthless. TNT is on the list not because the invention was a failure, but because it was not very good at its initial purpose, which was to work as a yellow dye. Personally, I'm glad that didn't work out as I'd hate to be wearing a tee shirt that could explode at any given time.
I agree that tetraethyl-lead is probably the worst thing ever inflicted on humanity, subtracting IQ points from everyone on the planet, at best. But "adversely impacted the atmosphere more than any single organism in the history of our planet" makes no sense for either CFCs or leaded gasoline...
that threatens to wipe oxygen off the face of the Earth... However, now we know that the compounds released by gasoline engines designed to turn oxygen atoms into chlorofluorocarbons may very well lead to the total depletion of the ozone layer.
CFCs can contribute to ozone (O3) turning into regular oxygen (O2), but I don't know what that has to do with removing oxygen from the face of the Earth, or how a compound released from an engine can turn oxygen into a CFC which contains no oxygen.