The environmental impact is still number_of_individuals * mean_consumption.

Urban areas often use more resources and generate more waste due to higher levels of economic activity. This contributes to a bigger environmental footprint.

Cities can also shift some of their environmental impact to rural areas or other states or countries where things like food production, resource extraction and waste disposal happen.

So, the true environmental cost of cities is often higher than it appears, especially when you consider the carbon emissions from transporting goods and waste.