I had a recent argument with a coworker (we are both engineers) that the amount of pollution (trash+water+air) generated by a person increases with the person's income (we both agreed on that) but my coworker claimed that the fact that person lives in a big city or in a small town does not affect the amount of pollution, which I don't agree.
I agree that it is hard to estimate the average pollution generated by these two different lifestyles. In big cities people are more inclined to use public transportation, will have smaller residences which in turn will require less heating (we are in France, so assume Paris), but they also consume more disposable items and the foodstock have to be transported from more distant places.
On the other hand people in big cities have higher income on average, thus they probably generate more pollution based on this, according to my coworker.
Thus, for the same income which lifestyle is more environmentally sustainable? Are there studies on this subject?