Diesel pollution is worse than petrol pollution, but the average European car is smaller, and there are fewer of them.

Many of the diesel vehicles are public buses, and these can be replaced pretty quickly with electric or natural gas (or hybrid) buses. Others are large delivery vehicles, and with some "encouragement" (restrictions) the owners either replace them, or rearrange their fleet to use their newest vehicles in cities.

For example, London has done both, and is already seeing improvements [1]. I noticed when I visited over New Year that the air seemed fresher, so I'm glad I've found some statistics to show that -- it wasn't just a one-off.

[1] https://www.london.gov.uk/sites/default/files/ulez_six_month...

Have you been in a French city of late? I almost couldn't visit Tours-centre because of all the diesel smell a few years ago.

It has improved slightly in the last 2 years but it will take a full adoption of EVs (and increased public transit) to resolve. It's not like France is lacking for fuel taxes or road taxes and insurance costs. Demand is still too high.

When I visited Paris, around 7 years ago, it was by far 2-stroke exhaust that was the problem. My Parisian coworkers, who also rode motorbikes, explained it was because the licensing and vehicle taxes are tiered by displacement. So everyone gets a small displacement 2-stroke, since a 2-stroke makes power equal to a 4-stroke double the displacement.

I haven't checked to see if this has changed since then.

Do you have a source for this? Diesel pollution is and was never a clear known spike at least I have never heard from your statement.

I’ll take “air next to a tree” vs “air next to a car” any day, regardless of average ambient. And I like cars a lot.