RE: Paris bans half of all cars from the road over pollution fears
It's more that similar schemes in other large conurbations such as Mexico City have had no effect (see Googlable source, below), and thus it could be construed that the Paris authorities are making a knee jerk decision on the path of least resistance rather than trying to understand the problem better and not be short termist about it.
Nobody is saying that ICE cars don't pollute, as that is demonstrably not the case (in Mexico, they are responsible for most of the pollution), more that mechanisms the people in power employ to deal with the fact rarely produce the intended effect, and end up inconveniencing millions of people for no reason.
Source: Davis, Lucas W. 2008. The Effect of Driving Restrictions on Air Quality in Mexico City.