[tombert]

It's not terribly hard to find data on NYC's carbon footprint per capita: http://www.eia.gov/environment/emissions/state/analysis/

From the article: "New York, with a population of 19.6 million people, had the lowest per capita CO2 emissions – 8 mt per capita. A large portion of the population is located in the New York City metropolitan area where mass transit is readily available and most residences are multi-family units that provide efficiencies of scale in terms of energy for heating and cooling."