A special report released in August by the National Research Council

A special report released in August by the National Research Council, Driving and the Built Environment: The Effects of Compact Development on Motorized Travel, Energy Use, and CO2 Emissions — Special Report 298, estimates that compact development would reduce greenhouse gases from transportation sources by 1 to 8 percent by 2030, and up to 11 percent by 2050. The NRC report supports the argument that vehicle miles traveled (VMT) is related to land-use patterns, which must be addressed to meet US climate goals. The report also points out that land-use regulations — zoning laws — are barriers to compact development. A pdf can be downloaded at www.nap.edu.

However, planners from the Metropolitan Research Center at the University of Utah criticize the report for underestimating the potential of land-use regulations to address climate change. “The NRC report reflects a conservative bias that is common in much academic work,” say Reid Ewing, Arthur C. Nelson, and Keith Bartholomew of the University of Utah. “It assumes that the distant future, even out to 2050, will not be very different from the world today.” In fact, they argue, “Changing household structure, sharply rising fuel prices, the imperatives of climate change, smart growth initiatives at the federal, state, and local levels will all pull in the same direction, in an unprecedented manner, toward compact development and reduced VMT.”

One of the underlying assumptions of the NRC report is that compact development reduces greenhouse gases by 5 to 25 percent. Ewing, Nelson, and Bartholomew say their research shows the real range is 20 to 40 percent. The response, called Response to Report 298, can be downloaded at www.smartgrowthamerica.org.