The reason that cities produce so much less carbon despite having so many people is because there is less driving and more centralized power, the least carbon emitting places are cities with clean energy and an urban tree canopy as well as decent public transiy
Suburbs are inherently inefficient and polluting due to their low density and large homes that make for places that need massive amounts of energy to exist and they waste enormous amounts heating and cooling homes due to the size and as the homes are spread out energy gets lost in the movement of the energy meaning more needs to be produced compounding the issues






