It makes sense that cities are the places where we can best reduce our impacts on the planet, and now there’s a study that quantifies the greenhouse gas (GHG) emissions and energy use from buildings, home heating, and transportation for suburban and urban areas of metro Toronto. The study by researchers at the University of Toronto appeared in The Journal of Urban Planning and Development.
This well documented assessment takes a close look at building materials used in urban development, the energy used to heat, cool and power dwelling, and the transportation energy of both urban and suburban residents. The study concludes that low-density suburban areas are more energy intensive by a factor of 2.0 to 2.5. Transportation is by far the largest factor in the difference between GHG emissions in a suburban context, and the automobile dependence of suburban residents is the cause.
Automobile use is clearly the most significant contributing factor to transportation impacts for both high-density and low-density development. In this context, and because of the much higher car dependence and vehicle-kilometers traveled by residents of the outer suburbs relative to the city core, per capita transportation-related GHG emissions and energy use associated with low-density development are found to be 3.7 times higher than those associated with high-density development.
The study clearly shows that an increase in residential density has a powerful impact on GHGs and energy use.