Compared to cities across the globe, Denver ranks as one of the highest per capita contributors of carbon emissions. (Kennedy et al 2009) Denver also ranks high within the United States, as total GHG emissions in Denver are 21.5 metric tons per capita, 25% higher than the national average of 17.2. Denver's per capita GHG emissions are double that of New York City, and 65% greater than Los Angeles. (Kennedy et al 2009) Coal-based electricity and a relatively cold climate, which requires more heating, drive the majority of Denver's emissions, but transportation is still responsible for 30% of total output. (City of Denver 2005)
The relationship between urban form and carbon emissions has been well-documented, with many studies showing the range of carbon reduction benefits that accompany a high density urban form:
"In denser urban areas, trip origins and destinations (e.g., home, work, shopping) are closer; driving disincentives (e.g., congestion, parking costs) are greater; and alternative modes of travel (e.g., walking, bicycling, mass transit) are more common." (Marshall 2008)
As we've noted in previous posts, Denver is a relatively low-density city, despite recent attempts to revitalize high density neighborhoods closer to downtown. Another indication of this carbon-intensive development pattern is that Denver ranks 20th among metropolitan areas in total vehicle miles traveled, with a 7.5% increase in VMT between 2000 and 2006. (Puentes and Tomer 2008)
But Denver's political leaders are making headway into reducing the carbon impact of the city. In 2005, they developed Greenprint Denver, an action plan to reduce the city's greenhouse gas emissions. In 2009, the city met their 2012 goal, to reduce GHG emissions to their 1990 level, three years ahead of schedule. (City of Denver 2011) While recognition is due for many specific actions taken by the city, two issues remain. First, the Great Recession of 2008/2009 mitigated emissions regardless of city initiatives, as reduced economic activity decreased energy use. Second, emissions are tracked only for the central city of Denver and do not include suburban cities that represent the majority of the population of the Denver region.
The FasTracks regional light rail investment is an important step toward low-carbon transportation policy in Denver, and the US Mayors Climate Protection Center agrees, awarding Denver Mayor John Hickenlooper with a Large City Best Practices Award in 2009. As the economy recovers and development activity increases, Denver's future success in reducing carbon emissions will rely on even more regional collaboration to ensure new growth takes a low-carbon form.
Marshall, J. D. (2008). Energy-efficient urban form. Environmental science & technology, 42(9), 3133–7. Retrieved from: http://www.ncbi.nlm.nih.gov/
Kennedy, C., Steinberger, J., Gasson, B., Hansen, Y., Hillman, T., Havránek, M., Pataki, D., et al. (2009). Greenhouse gas emissions from global cities. Environmental science & technology,43(19), 7297–302. Retrieved from: http://www.ncbi.nlm.nih.gov/
Puentes, R. and Tomer, A. The road less traveled: An analysis of vehicle miles traveled trends in the U.S. Brookings Metropolitan Policy Initiative. December 2008: Brookings Press. Retrieved from: http://www.brookings.
edu/~/media/Research/Files/ Reports/2008/12/16% 20transportation%20tomer% 20puentes/vehicle_miles_ traveled_report.PDF
City of Denver. Office of Sustainability, (2011).Greenprint denver: Progress report, 2006-2011. Retrieved from: http://www.greenprintdenver.
City of Denver. Office of Sustainability, (2005). Greenprint denver: Climate action plan. Denver, CO: City of Denver. Retrieved from: http://www.greenprintdenver.
org/docs/ DenverClimateActionPlan_A2. pdf?phpMyAdmin= uw3Ctvhe640MfMtUoF1W%2CdvORDc