Title: Growing Cooler: The Evidence on Urban Development and Climate Change – By Reid Ewing, Keith Bartholomew, Steve Winkelman, Jerry Walters, and Don Chen
Abstract: Growing Cooler: The Evidence on Urban Development and Climate Change . Washington, DC : ULI–the Urban Land Institute . 150 pages. ISBN 978-0-87420-082-9 , $39.95 cloth . Reid Ewing, Keith Bartholomew, Steve Winkelman, Jerry Walters, and Don Chen . 2008 . http://www.smartgrowthamerica.org/gcindex.html Metropolitan areas and the built environment are often neglected when solutions to the climate challenge are discussed, yet they are major emitters and they are poised to be part of the solution. This book makes a compelling case for compact urban development as an important contributor to climate change mitigation. Its main focus is on curbing the growth of vehicle miles driven in urban areas through a combination of higher overall density, mixed land uses, strong population and employment centers, interconnected streets, and human-scale design. Since 1980, the number of miles Americans drive each year has grown three times faster than the U.S. population. The combination of longer trips and single occupancy cars accounts for a large share of this increase, and the trend is expected to continue. Growing Cooler provides a systematic analysis of the potential for compact development to reduce CO2 emissions. It estimates that shifting 60 to 90% of new growth to compact development would reduce VMT by 30% and cut U.S. transportation CO2 emissions by 7 to 10% by 2050, relative to a trajectory of continued urban sprawl. This estimate is derived as a product of six factors, which parallel the organization of the book: "market share of compact development, reduction in VMT per capita with compact development, increment of new development or redevelopment relative to the base, proportion of weighted VMT within urban areas, ratio of CO2 to VMT reduction for urban travel; and proportion of transport CO2 due to motor vehicle travel." (p. 32) Other U.S.-based locational efficiency studies have projected greater and quicker potential for GHG reductions, with savings on the order of 10% of the 2001 level of GHGs produced in the United States suggested as possible within as few as 10 years (Burer, Goldstein, & Holtzclaw, 2004; Holtzclaw, 2004). The estimates provided by Growing Cooler are clear, well documented, and reasonable. The actual reduction in VMT per capita depends on how bad current development patterns are and how good alternative growth configurations can be, based on the so-called "five Ds" that characterize urban development patterns (p. 43). The original "three Ds" were coined by Cervero and Kockelman (1997): density, diversity, and design. Since then, destination accessibility and distance to transit have been added. Growing Cooler suggests that parking supply and cost should be considered as well. The body of literature surveyed in this book is extensive and the combination of quantification and photos and graphics is impressive. It helps the authors make the case that the rise in vehicle emissions can be curbed substantially by growing in a way that makes it easier for Americans to drive less. The potential of compact development to shrink driving distances is illustrated effectively through the use of case studies such as the excellent vignette on the Atlantic Station. The long-lived nature of buildings and infrastructure makes the reduction essentially permanent and compoundable. Pursuing smart growth is a low-cost climate change strategy because it involves shifting investments that have to be made anyway. Consistent with an expanding body of previous research, Growing Cooler also documents that infill locations generate substantially lower VMT per capita than do greenfield locations, from 13 to 72% lower based on a review of ten studies of individual developments. In accounting for the impact of smart growth, the authors characterize the tension between environmental determinism and self-selection. They note that researchers must properly account for the choice of neighborhoods; for instance, it may be that people who choose "new urbanism" would walk more and drive less than others wherever they lived. A second thesis of this book is that current government policies encourage sprawling, auto-dependent development. Government has largely overlooked the need to curb growth in VMT as a climate mitigation strategy in favor of the other two legs of the three-legged stool: improving vehicle efficiencies and decarbonizing fuels. As with the transportation sector, the United States has relied almost exclusively on technological advances rather than smart growth to address the energy and climate change challenges of the residential sector. Local land use planning has encouraged auto-dominated development; public spending has supported development at the urban fringes rather than redeveloping the urban core, and transportation policies remain focused on accommodating the automobile rather than alternatives. Growing Cooler recommends a strong portfolio of policy reform at the local, state, and federal levels. They are consistent with a list of federal policy recommendations recently released by the Brookings Institution (Brown, Southworth, & Sarzynski, 2008). Growing Cooler provides more cursory coverage of the residential sector's ability to curb its greenhouse gas emissions with compact growth. As with transportation, the book notes that residential energy use and related emissions have a relationship to urban development patterns. On the one hand, compact development has smaller living areas per capita but they are more prone to urban heat island (UHI) effects. They estimate that an average household living in a compact county, one standard deviation above the mean sprawl index, would consume 17,900 fewer Btu of primary energy annually, compared to the same household living in a sprawling county one standard deviation below the mean index. The UHI effect is 1,400 fewer Btu. Further probing would have been useful to incorporate the potential benefits of compact development for enabling highly efficient district energy systems for cooling, heating, and power generation; lower electricity transmission and distribution line losses; reduced municipal infrastructure requirements including communication, water, and sewage lines; and the use of microgrids to meet local electricity requirements with highly efficient, low-carbon systems (Brown & Southworth, 2008). With 65% of the nation's population and 76% of its economic output, the nation's 100 largest metropolitan areas warrant special consideration in climate policy. Nevertheless, rural America would also benefit from better land use planning. The concept of compact development in metropolitan America does not translate effectively to rural settings. This would be a useful focus for a sequel to Growing Cooler.