Lots of people, companies, cities , and nations have started to calculate their greenhouse gas (GHG) emissions, since you can only change what you can measure. These measurements are starting to highlight some very interesting trends and show how complex the global results of our lifestyle are.
In a recent paper Lorraine Sugar and I prepared on GHG emissions, with detailed neighborhood information for the City of Toronto (from University of Toronto researchers VandeWeghe and Kennedy) we highlighted that what you buy is important in determining your GHG emissions, but where you live is much more important. The three neighborhood images, all in the Toronto region, show how urban form is the most important determinant of your carbon footprint.
The neighborhood of East York has the lowest per capita emissions (1.3 t). It is an area with high-density apartment complexes that are within walking distance to a shopping center and public transit.
Etobicoke has medium GHG emissions per capita (6.62 t). It is a neighborhood of high-density single family homes close to the city center and accessible by public transit.
The neighborhood of Whitby has the highest per capita emissions (13.02t)—it’s located in the suburbs of Toronto with large, low-density single family homes that are distant from commercial activity and public transit.
The affluence of the three neighborhoods is roughly equal, however when where you live is relatively dense, well served by public transport, and many destinations are within walking distance, per capita GHG emissions can be much lower. The three neighborhoods are all within the Metropolitan Toronto area, yet per capita emissions vary by an order of magnitude.
Emission reductions brought about by banning shopping bags, buying organic food, or even encouraging more fuel efficient vehicles or higher rates of renewable energy, although important, will never yield an impact similar to what can be brought about by living in better designed, better served, and healthier neighborhoods.
The numbers associated with the Toronto neighborhoods above are only for residential emissions, and may not include other lifestyle impacts such as emissions from employment and international travel, which are also important contributors to GHG emissions. However these numbers do highlight the dramatic importance that urban form has on our per capita greenhouse gas emissions. This information is part of a paper submitted to Environment and Urbanization.
Looking at per capita GHG emissions is complicated, especially when you include all emissions within a city. For example, if a city has a major shipping port or airport, emissions will be relatively high. Or, if there is a high concentration of industry within the city limits, emissions will be higher. Availability of hydropower reduces emissions. Although calculating emissions can be difficult, city planners and policy analysts can only begin to build better cities when good, disaggregated information is available.
In an upcoming blog, we will look at the variation in per capita GHG emissions across Canada and why this is important for cities everywhere.