Study: Suburbs can pollute more than cities

Per capita emissions higher

Marci Gilbert, Feb 07, 11.

Carbon emissions in cities are lower per capita than in the car-dependent suburbs, according to a new study published in the journal Environment and Urbanization.

The Toronto-focused study found that public transportation and walkability reduce per-capita carbon emissions, especially in warmer cities that rely less on artificial heating. Two important generalizations include:

Suburbs are last in emissions: Maps from the Center for Neighborhood Technology show that while cities have the highest emissions per square mile, suburbs have the highest emissions per person. A single acre in New York is going to pollute more than an acre of strip mall in Scottsdale, but that’s because New York City buildings are full of people on top of each other.

Density is pretty much the most important thing: A 2009 National Research Council report looked at the relationship between dense city layouts, vehicle use, and carbon, and recommended “policies that support more compact, mixed-use development and reinforce its ability to reduce [vehicle miles traveled], energy use, and CO2 emissions.” NRC reports can be a little dry, but here’s the upshot: Dense living is the way to go, and we should encourage it.

Economist Edward Glaeser’s illustrates the report with numbers:

New York City has the largest gap in emissions between central city and suburbs of any metropolitan area in the country-unsurprisingly, since New York’s central city is the epitome of dense urban living. Our estimate is that an average New York City resident emits 4,462 pounds less of transportation-related carbon dioxide than an average New York suburbanite. The reductions in carbon emissions from home heating and electricity are comparably large, thanks to New York’s famously tiny apartments. Manhattan is one of the greenest places in America.

Source: Grist.org
Photo Source: Green Futures Blog