From the October/November 2007 issue of New Urban News

Warming up to smart growth

Robert Steuteville
Compact development patterns are essential to fighting climate change, according to a report from a development industry association.

There is little chance that the US will meet ambitious targets for carbon dioxide emission reductions without a major switch to smart growth and New Urbanism, according to a book-length report published by the Washington, DC-based Urban Land Institute. Growing Cooler: The Evidence on Urban Development and Climate Change,
places compact development on par with fuel efficiency as an essential tool in fighting global warming.
The authors conducted “an exhaustive review of existing research on the relationship between urban development, travel, and the CO2 emitted by motor vehicles,” ULI says. More than 100 rigorous studies have been completed in this area, according to authors Reid Ewing, Keith Bartholomew, Steve Winkelman, Jerry Walters, and Don Chen. “A meta-analysis of many of these types of studies finds that households living in developments with twice the density, diversity of uses, accessible destinations, and interconnected streets when compared to low-density sprawl drive about 33 percent less.”
Although every metro area in the US has sprawl, those that sprawl less generate far fewer vehicle miles traveled (VMT) per person, studies have shown (see Figure 1). At least three published studies in recent years have shown that new urban site design reduces vehicle trips and/or VMT by 20 percent or more.With the right infill location and transit access, even greater reductions are likely, the authors note. Shifting 60 percent of new growth to compact development by 2030 would have the same benefit as a 28 percent increase in US fuel efficiency, they estimate. If combined, these policies would produce an even greater benefit.
To prevent temperatures from rising by more than 2 or 3 degrees Centigrade, the scientific consensus is that greenhouse gases will have to be cut 60 to 80 percent below 1990 levels by 2050, the authors note. Given that greenhouse gases have already risen 20 percent since 1990 — and the US population will grow by 100 million by mid-century — the task is daunting and may be impossible without compact development patterns, according to Growing Cooler.

SPRAWL AND GLOBAL WARMING
Sprawl contributes substantially to greenhouse gases. Since 1980, the number of miles driven by Americans has grown three times faster than the nation’s population (see Figure 2, below). This increase in vehicle miles traveled (VMT) is the result of 60 years of sprawl, the authors write. “As a larger and larger share of our built environment has become automobile dependent, car trips and distances have increased, and walking and public transit use have declined.”
(The report’s statement about declining public transit use is contradicted by the American Public Transportation Association (APTA), which said in March that public transit use grew 2.9 percent in 2006 and jumped 30 percent from 1995 to 2006. Over the past decade, public transportation’s growth rate has outpaced both the growth of population and the growth of VMT, according to APTA President William W. Millar.)
Regardless, total VMT is still increasing, even if less rapidly than before gasoline prices shot up. Developed land is growing at three times the population growth rate. Market and demographic trends support a switch to compact development, the ULI authors report.
“There is no doubt that moving away from a fossil fuel-based economy will require many difficult changes,” they write. “Fortunately, smart growth is a change that many Americans will embrace.” The authors present evidence — previously reported in New Urban News — that most of the demand for new housing in the next quarter century will be in the form of compact development. (See article in this issue on the current housing slump, in which infill development and New Urbanism appear to be generally outperforming conventional, low-density sprawl).
The authors are not necessarily proposing high-rise development or even uniformly high densities, “rather higher average ‘blended’ densities,” they explain. Compact development would also save money on public infrastructure and promote health, they add.
Congressional discussions on reducing carbon dioxide emissions in the transportation sector — which generates a third of greenhouse gases in the US — have focused largely on boosting automobile fuel efficiency. California plans to implement a standard to lower the carbon content of fuel by 10 percent by 2020.
Even if the most ambitious standards on the table in Congress and California are met nationwide, carbon emissions in the transportation sector could still rise 12 percent by 2030, due to anticipated increases in VMT (See Figure 3, above). That would put us at 40 percent above 1990 levels — on a track that would make substantial mid-century reduction targets impossible to meet, the authors explain.
“The key to substantial greenhouse gas reductions is to get all policies, funding, incentives, practices, rules, codes, and regulations pointing in the same direction to create the right conditions for smart growth,” the authors say.
The report, expected to be available from ULI as a softcover book for $19.95 in December, does not address potential energy savings from more efficient buildings. However, it comes at a time when the green building industry is becoming more aware of the value of compact development. Environmental Building News, a green building trade publication, reports in its September 2007 issue that consumption of energy in getting to and from office buildings exceeds energy use in the buildings themselves.
This article is available in the October/November 2007 issue of New Urban News, along with related and other articles not available online. Subscribe or order the individual issue.