The narrative in the EU the last 10 years has been that if we don't release less CO2 we'll drown the dutch and the Seychelles by next year, so the plan seemed to be to quickly cut CO2 in half, no matter what. The EU-norms do put restrictions on many types of pollution, but only CO2 is ever discussed. Tax breaks and company purchase restrictions and so on on are normally based on the CO2 emissions alone.

There has been little/no discussion about pollution other than greenhouse effect, and even among those pollutants, basically only CO2 is ever discussed in relation to cars (Methane sometimes when discussing meat).

I don't see the EU5/EU6/... pollutions norms as being complete failures. They haven't only switched europe to diesels, they have brought all combustion engines down to very good consumption, even better when you factor in that the power has actually kept on increasing. Petrol enginess too have become very lean too, and people do buy them still. The latest VW Tiguan SUV is available with a 1.4L 150hp gasoline engine (In Europe that is, in the US it's only available with the 2.0Litre. Basically the US had the option to get 2 trims of Tiguan -- the lean one and the performance one, while still avoiding the diesels. But the lean one wasn't even an option apparently).

As for Europe, this year will probably see 10% hybrids (for larger cars in the nordic/western market at least, I only know those markets), and within 3-5 years the hybrids will be competitive enough to replace diesels completely, especially if the subsidies are moved from diesels to hybrids.

Well. More gas used = more CO2 released. Arguably, that's bad.