The EU didn't think this through and simply switched pollutants from CO2 to
NOx and particulates:
http://www.businessweek.com/articles/2014-06-05/london-leads-eu-in-car-pollu
tion-diesel-fuel-blamed  It's going to take a long time to replace their
diesel fleet with clean diesel vehicles.

In the US since 2007 we've been doing better with low sulfur diesel fuel,
clean engine design, particulate filters and post-treatment like urea
injection: http://www.epa.gov/otaq/technology/420f04023.pdf  But even with
this it will take until 2030 to see the full benefits.

We are much better off having minimum clean air standards and a mix of gas,
diesel and electric cars we can choose from.

Just so they don't start going after old cars . . .

Stuart