Polarizing Evidence of the Relationship between Compact City and the Carbon Footprint of City Residents

Compact cities, where people live together in closer proximity and higher density, are expected to reduce greenhouse gas emissions. At the same time, these dense urban areas are associated with agglomeration economies, where increasing population correlates with the increasing productivity. Furthermore, population and dense urban areas also correlate positively with wages and housing prices. This is critical to an understanding of emissions sources as income is the main driver of personal carbon footprint and economic growth the main driver of global GHGs. This chapter examines how the compactness of a city is connected to the income and carbon footprints of the residents of a city. We focus on the transport and housing sectors, as these are the emissions that compact-city policies generally target. The study includes the 20 largest cities in Finland and the carbon footprints are calculated with an input-output based hybrid life cycle assessment method and elaborated with regression analysis. The results of the study depict how the compactness of a city is associated with increasing income and increasing carbon footprints. The emissions caused by driving decrease moderately with increasing population and compactness, but the emissions caused by other travel (public transport and holiday travel) increase strongly. The emissions caused by housing energy consumption do not have a statistically significant connection to the population or compactness of a city, even though the living space per capita slightly decreases with these. The results indicate that if decision-makers wish to build compact cities specifically for the possible economic benefits, they have to understand that this is in contradiction with environmental goals.