At first glance, cities may appear to be a big source of the greenhouse gases that contribute to global warming. But new research by the nonprofit Center for Neighborhood Technology (CNT), which compares greenhouse gas emissions of city and suburban households, yields some surprising results.
CNT, which launched I-GO Car Sharing in 2002, looked at emissions of carbon dioxide, a key greenhouse gas, stemming from household vehicle travel in 55 metropolitan areas across the U.S. When measured on a per household basis, it found that the transportation-related emissions of people living in cities and compact neighborhoods can be nearly 70% less than those living in suburbs. See how this compares in your region. (Click on “Household Auto Greenhouse Gas Emissions.”)
“Cities are more location-efficient—meaning key destinations are closer to where people live and work,” said Scott Bernstein, CNT’s President. “They require less time, money, fuel and greenhouse gas emissions for residents to meet their everyday travel needs. People can walk, bike, car-share, take public transit. So residents of cities and compact communities generate less CO2 per household than people who live in more dispersed communities, like many suburbs and outlying areas.
“If you’re deciding where to live, consider moving to an urban area. You’ll help fight global warming by emitting less CO2. And you’re likely to drive less, so you’ll spend less on transportation, saving up to $5,000 annually.”
CNT’s research shows that average transportation costs vary greatly depending on location, from a low of 14% of area household median income in transit-rich, compact communities, to highs of 28% or more in exurban areas where employment, retail, and other amenities are more dispersed.
CNT focused on vehicle travel as a source of emissions, since research shows that transportation accounts for 28% of all greenhouse gases in the U.S. Its work compares the conventional per-acre analysis of greenhouse gas emissions due to vehicle travel with a new per-household view in each metropolitan area it studied. The results suggest that, due to their density and transportation alternatives, cities are a central part of the climate change solution.
The research is an outgrowth of CNT’s Housing + Transportation Affordability Index, which examines several aspects of location efficiency. One is the true cost of housing when household transportation costs are factored in, which vary widely by location. Together, transportation and housing can account for more than 60% of annual household expenses for some working families living in outlying areas—significantly impacting their cost of living and quality of life. The site also illuminates the environmental cost of housing location, which includes impacts like household carbon dioxide emissions.
Since its launch a year ago, the H+T Affordability Index has been expanded to show current CO2 maps, as well as the impact of location and gasoline costs on household budgets between the years 2000 and 2008. It has also been redesigned and enhanced for ease of use and data access.
With generous funding from the Rockefeller Foundation, the index will be expanded to cover more than 330 metropolitan areas in the U.S. later this year.
Founded in 1978, CNT is a Chicago-based nonprofit organization that works nationally to advance urban sustainability by researching, inventing and testing strategies that use resources more efficiently and equitably. Its programs focus on climate, energy, natural resources, transportation, and community development. CNT is one of eight nonprofits selected from around the world to be recognized by a 2009 MacArthur Award for Creative and Effective Institutions, from the John D. and Catherine T. MacArthur Foundation.
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