Have you considered that one day the electric power to fuel these cars may not be coming from "dirty sources". If we have a chain like this "dirty -> clean" which enables the possibility of " clean -> clean", isn't that better than a chain which leads from " [clean|dirty] -> no change dirty"? Supposing we do wean ourselves off of the fossil fuel industry as you may envision. Do you think that involves have "dirty" cars and "clean" supply chains? Converting electricity and hydrogen [ yes electricity can be collected directly from "clean sources" and hydrogen can be formed from H20 using electricity] to carbon may be feasible one day, but there is no reason do that if we have electric or hydrogen powered cars which use this clean energy. Of course electric cars cost more to produce now, blah blah blah, more pollution goes into their production, blah blah blah, but the first problem is a problem of scale, and the second problem can be eliminated by using "clean" energy sources in their production.[ another part of the clean supply chain ]. We are going to have to make a serious commitment. Or is that the point "we will have little need for carbon once we switch" is the part that is bothering the "sceptics"? Even if you don't care where we get our energy from, it still has to be there.