Not arguing with the point being made here, I completely agree, but I do want to set one thing straight: I live in Europe, and I've been to many streets that are closed to vehicle traffic, and I see visibly disabled people and people with walking aids in those places all the time. Always have. I've walked around those places with someone who uses a cane. Just because they aren't in whatever photo you saw doesn't mean they don't exist.
It's not a climate thing. Pedestrian-only streets are necessary in towns that were built before cars. They are usually the main shopping street(s), where having cars drive through is dangerous in more than one way - especially for disabled people and children. The streets and footpaths are too narrow for the level of traffic we have now. If you let cars through there, you'd make the main shopping street inaccessible or at least super dangerous for elderly ladies with walking aids, people in wheelchairs, people with babies in buggies, etc. Not ideal. Pedestrianised places are accessible for those people, the important thing is making sure they can get there. Which, in those photos, you probably also aren't seeing the car parks that are usually right next to those streets, often underground.
I think maybe this is a case of people trying to apply a European solution 1:1 to the US, and you can't. First of all, you don't even have the same problem. Pedestrian-only streets in a German town are imo more comparable to a US shopping mall. You don't drive around inside those, either, right? Even if you are disabled, you leave the car outside. Same thing here.
Also: the European problem is that medieval towns weren't built for cars. The streets are tiny. So you have to adapt them, using one-way systems and pedestrian zones. They don't just close a street, they plan this out to make sure everything's still accessible. You can still drive around it, park next to it, get there by bus, etc. It's a matter of adapting a medieval town to modern needs, including the needs of elderly and disabled people.
Anyone sharing this as some kind of climate-conscious car-banning thing doesn't know what they're talking about.