If you are looking for a major contribution to climate change, you need walk no further than your front door, a new book suggests.
Growing Cooler: The Evidence on Urban Development and Climate Change, published by the Urban Land Institute, is a comprehensive review of dozens of studies in which the researchers conclude that urban development is both a key contributor to climate change and an essential factor in combating global warming.
ULI is a nonprofit education and research institute supported by its 38,000 members. It's mission is to provide leadership in the responsible use of land.
The researchers warn that if sprawling development continues to fuel growth in driving, the projected 59 percent increase in the total miles driven between 2005 and 2030 will overwhelm expected gains from vehicle efficiency and low-carbon fuels.
Even with projected efficiency improvements, they say, vehicle emissions of carbon dioxide would be 41 percent above today's levels, rather than well below 1990 levels as required for climate stabilization by 2050.
"Curbing emissions from cars depends on a three-legged stool: Improved vehicle efficiency, cleaner fuels, and a reduction in driving," said the lead author, Reid Ewing, who is a research professor at the National Center for Smart Growth at the University of Maryland. "The research shows that one of the best ways to reduce vehicle travel is to build places where people can accomplish more with less driving."
Depending on several factors, from the mix of land uses to pedestrian-friendly design, compact development reduces driving from 20 percent to 40 percent, and more in some instances, the authors of the ULI book suggested. Typically, Americans living in compact urban neighborhoods where cars are not the only transportation option drive 33 percent fewer miles than those in automobile-oriented suburbs, according to the researchers.
At the same time, the book documents market research showing a majority of future housing demand lies in smaller homes and lots, townhouses, and condominiums in neighborhoods where jobs and activities are close at hand. The researchers note that demographic changes, shrinking households, rising gas prices, lengthening commutes and cultural shifts all play a role in that demand.
The report cites real estate projections showing that two-thirds of development expected to be on the ground in 2050 is not yet built, meaning that the potential for change is profound. The authors calculate that shifting 60 percent of new growth to compact patterns would save 85 million metric tons of carbon dioxide annually by 2030. The savings over that period equate to a 28 percent increase in federal vehicle efficiency standards by 2020 (to 32 miles per gallon), comparable to proposals being debated in Congress.
"Clearly, the development industry has a key role in the search for solutions to offset the impact of climate change," said ULI Senior Resident Fellow William H. Hudnut.
"Whether close-in or in suburbs, well-planned communities give residents the option to walk, bike or take transit to nearby shopping, retail and entertainment. Being able to spend less time behind the wheel will benefit our health, our pocketbooks and the environment."
Implementing the policies recommended in the report would reverse a decades-long trend. Since 1980, the number of miles Americans drive has grown three times faster than population, and almost twice as fast as vehicle registrations. Spread-out development is the key factor in that rate of growth, the research team stated.
The findings suggest that people who move into compact, "green neighborhoods" are making as big a contribution to fighting global warming as those who buy the most efficient hybrid vehicles, but remain in car-dependent areas.
While demand for such smart-growth development is growing, government regulations, government spending, and transportation policies still favor sprawling, automobile-dependent development.
The book recommends changes in all three areas to make green neighborhoods more available and more affordable. It also calls for including smart-growth strategies as a fundamental tenet in upcoming climate change legislation.
The study represents a collaboration among leading urban planning researchers, including Ewing, Keith Bartholomew of the University of Utah; Steve Winkelman of the Center for Clean Air Policy, and Jerry Walters of Fehr & Peers Associates.
The National Center for Smart Growth Research and Education, now in its seventh year, is a nonpartisan center for academic research and leadership training on planning and development issues in the United States and around the world.
The Center for Clean Air Policy, which began in 1985, is an independent nonprofit organization developing pragmatic solutions that balance both environmental and economic interests.