Is that established? I believe that there are major giant cities that operate with a lower CO2 footprint than suburban and rural areas might, per capita. But

Is that established? I believe that there are major giant cities that operate with a lower CO2 footprint than suburban and rural areas might, per capita. But there is the cost of all the CO2 that allowed that urbanization; NYC didn't get the subway without a carbon cost, all that steel in the buildings released a lot of carbon, etc..