As a start, cities could have a lower carbon footprint if a sufficient number of facilities like schools and workplaces were placed very close to homes, this way, less travel and therefore less greenhouse gases would be needed for people to reach their daily destination. Fortunately many, but not all cities have already had this. Additionally, the widespread use of free public transportation would also lower the city's carbon footprint. Things like buses, if not electric, produce more emissions than one car, but if the bus is usually at full capacity, the emissions per capita are lower than if everyone drove a car each. It would be even better if electric buses could be used instead.

I agree with what you are saying about trying to place schools and workplaces in more efficient areas around homes. I do think though many cities are trying to pivot into a full public transportation model. With busses, ubers, and trams, they are making progress into this initiative. The pandemic had a big halt in public transportation as it turned into more of a comfort problem over an easier ride problem. I think with the pandemic slowly getting better, cities will start to go back into full ride share/public transportation mode.