Can a City Be Sustainable? (State of the World)
Edited by Gary Gardner, Tom Prugh, and Michael Renner for The Worldwatch Institute.
Island Press
2000 M Street NW, Suite 650
Washington, DC 20036
www.islandpress.org
May 2016. 256 pages. Paperback, $25.00.
Cities urgently need to find a way to reduce their carbon footprint. By 2009, more than half of the world’s people lived in cities. By 2040, all world regions, including Africa, will be majority-urban. Perhaps because cities are economic engines, producing some 80 percent of global gross domestic product (GDP), they account for 75 percent of the world’s carbon emissions.
“Urban living is one of the key drivers of unsustainability,” said Ed Groak, chairman of the Worldwatch Institute, at the recent launch of the 2016 State of the World report, Can a City Be Sustainable? Despite the many challenges, the report indicates that the answer is yes. The Carbon Neutral Cities Alliance, formed in 2014, is a coalition of international cities jointly seeking to cut greenhouse gas emissions 80 percent by 2050.
A sustainable city is “a vibrant human settlement that provides ample opportunities, in harmony with the natural environment, to create dignified lives for all citizens,” said Gary Gardner, director of publications at Worldwatch, who oversaw the report. Some principles of sustainable cities include the following: They are compact and connected (a function of density), clean and efficient, rooted in nature, interactive, and centers of well-being, and they offer decent work and a living wage and are broadly governed by policies built around human needs.
Transportation and the built environment are critical factors that can make a city sustainable, or not. A sustainable city needs multimodal transportation instead of sprawl and car dependence, said Michael Renner, senior researcher at Worldwatch. Those characteristics are connected with land use and zoning codes. Globally, Atlanta, Houston, San Francisco, Los Angeles, and New York create the most transportation-related energy consumption per capita, while London, Paris, Rome, Berlin, and Toyko create much less.
Sprawl is also related to the high cost of housing in many city centers. “Housing should be affordable so the less wealthy aren’t pushed out far away from jobs” to areas where they have to drive long distances to work, said Renner.
Buildings of all types are a big contributor to a city’s carbon footprint, generating 34 percent of greenhouse gas emissions annually. New construction can be more sustainable if the architect simply follows good design practices such as orienting a building to maximize light and insulation.
Green building standards such as Leadership in Energy and Environmental Design (LEED) are an important piece of the puzzle. The Living Building Challenge, used in the United States and Canada, is more comprehensive, grading buildings on site, water, energy, health and happiness, materials, equity, beauty, and process. The Bullitt Foundation headquarters in Seattle has won certification by generating all its own electricity, using only water that falls on the site and incorporating sustainable materials, among other measures.
But improvements in buildings’ energy efficiency have been modest, especially for retrofits, which achieve an average 15 percent savings in energy use. The rate of improvements must be dramatically improved, said Gregory Kats, president of Capital E, which works with cities, corporations, and financial institutions to implement clean-energy and low-carbon strategies.
The biggest obstacle, said Kats, is financing, mainly because building owners often need to see a quick payback before they are willing to invest in clean-energy measures. One problem is that the savings default to the utility instead of to the building owner, a setup that Kats said must change. He advocates tax rebates for building owners who meet aggressive energy efficiency targets, preferably in the same year the upgrade occurs. Although the city would pay a lot of money upfront, it would realize savings over several years in lowered air pollution, better health, increased employment, and other benefits.
In exchange for aggressive energy efficiency measures, cities should offer developers accelerated planning and zoning and more flexibility on density requirements such as those for floor/area ratio, Kats said.
Other construction measures such as green roofs or cool roofs can improve a building’s energy efficiency. Planting certain types of greenery on a roof can also improve air quality, increase biodiversity, help with stormwater management, and help with urban farming, said Renner. Cool roofs with white or light colors can cut air-conditioning use for a single-story building by up to 15 percent.
In transportation, various efforts have been made to curtail car use. Congestion pricing has worked well in cities such as London, where people who drive into the city pay a toll. One way to improve political support for congestion pricing is to make sure the revenue is used for mass transit, said Colin Hughes, director of policy at the Institute for Transportation and Development Policy.
“The benefit must be experienced by everybody,” Hughes said.
In some cities, restrictions are placed on who may drive on which days. Other cities have zones in which only low-emission cars can drive. Oslo is experimenting with completely car-free zones.
Car-sharing services such as Zipcar are now available in more than 1,000 cities worldwide. Annapolis, Maryland, is working to introduce car sharing for lower-income residents. If the primary goal is access, not mobility, then owning a car may no longer be necessary for as many people, said Hughes.
Other options discussed included more equitable transportation systems. Bus rapid transit is one. Several Latin American cities now have bus-only lanes, with fares collected before boarding to save time. Bike-sharing services are available in 710 cities globally. They should be expanded to lower-income residents, Renner said.
