The Criteria of a Green City

In compiling the list, points are given in the following categories:

Air Quality: Exposure to polyaromatic hydrocarbons (PAHs) from fuel exhaust and cigarette smoke has been reported to increase the risk of breast cancer by 50 percent, as noted in the 2002 Long Island Breast Cancer Study. In order to measure air quality, we based our score on the EPA’s Air Quality Index (AQI) and smoking bans noted on the Smoke Free World website. About 60 percent of cities surveyed have passed a smoking ban. AQI values are broken into five different ranges with lower values indicating less polluted air (Good 0-50, Moderate 51-100, Unhealthy for Sensitive Individuals 101-150, Unhealthy 151-200, Very Unhealthy 201-300 and Hazardous 301-500). Anchorage, Alaska, had the best median AQI at 19 while the worst was a 79 in Saint Louis. The average value was 43.5 for cities participating in this study.

Electricity Use and Production: Close to 40 percent of U.S. emissions of the greenhouse gas carbon dioxide (CO2) comes from electric utilities. Since coal accounts for over 90 percent of these emissions, we asked survey respondents to note each city’s energy mix from resources including coal, oil, biomass, geothermal, hydroelectric, nuclear, oil, solar and wind. Also included were incentives for the home use of solar or wind power, such as rebates or property tax exemptions.

Environmental Perspective: City administrators were asked to rank from 1 (highest) to 9 (lowest) nine issues in order of importance to city residents—education, employment, environmental concerns, health care, housing costs, public safety, reliable electricity and water service, property taxes and traffic congestion. Scores were assigned depending on the ranking given to environmental concerns. Out of a total of nine, the average ranking for the importance of environmental concerns was 5.4.

Environmental Policy: In our survey, we asked city officials whether the city has an environmental policy, a specific indication of concerted effort at the municipal level to better the environment. Thirty-six cities, or 58 percent of respondents, had such statements.

Green Design: The resource-conserving, non-toxic standards of USGBC’s Leadership in Energy and Environmental Design (LEED) program have become the basis for many cities’ green building projects. Recognizing this, we based scores not only on survey responses about policies and incentives for green design but also on LEED projects listed on the USGBC’s website. While we collected data on the degree of LEED certification (Certified, Silver, Gold and Platinum) buildings achieved, this did not affect scoring. Additional points were given to cities reducing sprawl. A total of 29 cities, or 46.8 percent of participants, reported having a policy to encourage green design. Forty cities, or 64.5 percent of respondents, reported having a city policy to help prevent sprawl.

Green Space: Survey respondents were asked to identify the variety of green spaces, including athletic fields, city parks, public gardens, trail systems and waterfronts, along with any additional spaces. This question was designed to elicit the variety of outdoor amenities available and was scored on the total number of different types of green spaces present. Scoring also considered the percentage of overall city area occupied by green space.

Public Health: Scores were based on Robert Weinhold’s rankings of the 125 healthiest U.S. cities as published in the March 2004 Organic Style.

Recycling: Survey respondents were asked to indicate which items their city recycles from a list that included aluminum, cardboard, glass, hazardous materials, paper, plastic, tin and other. Cities that had more then seven categories of recyclable items were given the highest scores.

Socioeconomic Factors: Having considered affordability in 2005, this year The Green Guide expanded the analysis to consider the impact of income on the ability of urban residents to lead healthy lives. Cities scored well for having less than the national average of families and individuals earning below the poverty rate. Participants also gained points for having a city minimum wage and for the availability of housing affordable to families earning the area’s median income according to the National Association of Home Owners’ Housing Opportunity Index.

Transportation: Wishing to recognize efforts to get people out of their cars (reducing greenhouse gases, traffic congestion and smog), we asked survey respondents about the transportation options available, including bicycle paths, bus systems, carpool lanes, dedicated bicycle lanes, light rail, sidewalks/trails and subways. As a follow up to this, we also asked about the percentages of residents who used public transportation, rode bicycles to work and carpooled.

Water Quality: In order to assess this complicated factor, we drew on data from the EPA’s Safe Drinking Water Information System (SDWIS) and noting violations of the Safe Water Drinking Act, with the greatest weight given to health violations.

 

Each of these factors was equally weighted, with a maximum score of 1 point per criterion, to create an overall maximum possible score of 11 points, though only one city we looked at, Eugene, Oregon, scored 9 or better. Unfortunately due to lack or response or incomplete surveys, some cities that might have ranked higher are not included here.

note: Eugene would not have registered as high if there had been independent verification of these factors.