[rosetremiere]

> and have a lower environmental impact than small towns

Can you expand on that (or link to more) ?

[dublinben]

You can see a map of household carbon footprint by ZIP code on this map: https://coolclimate.org/maps

A cursory glance shows that the densest urban centers have the lowest carbon footprint. The suburbs are much higher, with affluent suburbs often being more than twice as high. Only some very rural areas approach levels as low as the cities.

[orwin]

Look at 'Strong towns'. Not exactly what GP said, but close enough.