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The Top 10 Green Cities in the U.S.: 2006

For this Earth Day, recognizing that cities across the country are providing energy-efficient, least polluting and healthy living spaces, The Green Guide presents the environmental leaders, those cities whose green achievements set the standard for others. By P.W. McRandle and Sara Smiley Smith

As The New York Times has reported, in the absence of federal direction, cities across the country are taking environmental stewardship into their own hands and reducing their burden on the planet. Mayors are even working to lower greenhouse gases: As of March 28, 2006, 220 had signed the U.S. Mayors Climate Protection Agreement, which now covers urban areas housing 43.8 million Americans.

Our metro areas can be the focus of many ills -- from layers of asthma-inducing smog to pesticide exposures and gas-wasting sprawl. Yet, being tightly packed also allows them to run more efficient public transportation and creates a tax-base for green building and environmental programs smaller communities can't afford. Thomas Jefferson famously expressed his distrust of cities, but now, along with community gardens and other green spaces, some of the rural virtues he extolled have finally found their way into urban life.

Last year on Earth Day, The Green Guide recognized ten green cities and a handful of runners up. This year, in response to widespread interest, we pursued a more comprehensive evaluation, ranking each city on its performance over several criteria. We sent out surveys to mayors' offices in all 251 metropolitan areas with populations of 100,000 or more. By scoring survey responses in combination with information from the Environmental Protection Agency (EPA), the U.S. Green Building Council (USGBC) and other independent sources, we came up with our ranked list of the top 25 green cities in the U.S., giving special recognition to the top 10.

Among last year's awardees, Austin, Portland, Honolulu and Oakland remain in the top 10. Along with Seattle and San Francisco, Minneapolis made it to the top 20, while sister city St. Paul now occupies fourth place. Since we required a minimum population of 100,000, Boulder, which remains a gem among green cities, couldn't be considered in this round, while Madison and Chicago did not score as well due to incomplete surveys. The survey was designed and its results analyzed by our co-author and researcher Sara Smiley Smith, a graduate student at the Yale School of Forestry and Environmental Studies under the supervision of John Wargo, Ph. D., professor of environmental risk analysis.

As more citizens and leaders invest their energy in cities, helping prevent urban sprawl, reduce traffic and clean the air and water, we are excited to report again on their progress in the years to come.

The Criteria

In compiling the list, we gave points 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%, 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% 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% of U.S. emissions of the greenhouse gas carbon dioxide (CO2) comes from electric utilities. Since coal accounts for over 90% 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% 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% of participants, reported having a policy to encourage green design. Forty cities, or 64.5% 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.

Top 10 U.S. Green Cities

1. Eugene, OR (score 9.0375, pop. 137,893)

First on our list is the university town, Eugene, well known as a powerhouse of green industry, clustering sustainable businesses like an environmentally minded Silicon Valley. Nestled in the Willamette River Valley with views of the Cascade Mountains, residents enjoy numerous bike trails, clean air and water, parkland and outlying wilderness areas. Hydroelectric and wind power contribute over 85% of Eugene's power, reducing greenhouse gas emissions considerably. A little over 16% of Eugene is green space, including athletic fields, city parks, public gardens, trails and waterfront. The city has over 2,500 acres of publicly owned wetlands, and its West Eugene Wetlands Program includes a mitigation bank, a native plant nursery, protected wetlands and educational features.

"Overall, we have a reputation for protecting the environment and that reflects a commitment throughout the city organization to look for ways of becoming more sustainable," says Jim Carlson, assistant city manager, citing the city's biodiesel and hybrid fleets, its evaluation of all city activities for environmental impact and the mayor's sustainable business initiative to green the local economy. And Carlson notes that "In next year's budget, we're planning to purchase 25% wind power for all existing general fund buildings such as libraries and city hall."

2. Austin, TX (score 8.5325, pop. 656,562)

Austin reappears in our top 10 list where once again it stands out for its commitment to solar power and green building. Offering its customers one of the highest solar power rebates in the country, Austin plans to meet 20% of its energy needs with renewable sources by 2020. Austin's Green Builder program provides information for homeowners, renters and members of the design and building professions to help build more energy efficient and environmentally sound dwellings. For their central business district, Austin has established minimal requirements for energy efficiency and is considering requiring reflective roofs. Austin's Smart Growth Initiative is designed to preserve drinking water quality, ensure proximity to mass transit, and maintain a pedestrian-friendly urban design. And it's S.M.A.R.T. (Safe, Mixed Income, Accessible, Reasonably Priced and Transit Oriented) Housing offers incentives to developers to create more affordable housing.

3. Portland, OR (score 8.24, pop. 529,121)

Portland also returns from last year's list, not a surprise, perhaps, for this evergreen city which has directed all of its departments and agencies according to its Sustainable City Principles since 1994. The principles, which cover the protection of natural resources, habitat and ecosystem conservation and minimizing human impacts on the environment both locally and worldwide, haven't languished on paper these last 12 years. The first U.S. city to have a plan to reduce the greenhouse gas carbon dioxide, Portland gains 44% of its energy from hydroelectric sources and encouraging the installation of solar power through municipal tax incentives. Light rail, bicycle lanes and buses help keep residents out of their cars, with 13% relying on public transportation for their commute to work, 2% bicycling and 11% carpooling. Portland not only recycles the standard glass, metal and plastics, but also composts residential yard waste and food scraps from businesses. To enjoy their green city, residents have over 92,000 acres of green space (over 11% of the total city area) ranging from waterfront areas to trails, athletic fields, parks and public gardens.

4. St. Paul, MN (score 7.805, pop. 287,151)

With a quarter of its area given over to green space, St. Paul almost seamlessly integrates urban life with the natural environment. And this will improve as the city charter not only ensures the protection of parkland but requires expanding public access to the Mississippi River which winds through the city. Working to reduce global warming, St. Paul has passed its 1997 goals in CO2 emissions-reduction goals and now plans to reach a 20% reduction of 1988 C02 levels by 2020. To achieve this, Rick Person, program administrator for St. Paul's Department of Public Works, says the city will need to complete its central corridor light-rail system and adopt a 20% renewable energy portfolio. To assist residents in installing renewable energy, the state provides property tax exemptions for the value of the system, and St. Paul's Neighborhood Energy Consortium (NEC) provides assistance and expertise in obtaining Energy Efficient Mortgages. Helping reduce congestion and smog, NEC's Hourcar program provides hybrid and energy-efficient cars at neighborhood level for shared use. Lastly, St. Paul's requirement that 20% of all new housing units be affordable by those with incomes less than half of the area median ensures that these environmental benefits will remain available to all.

5. Santa Rosa, CA (score 7.785, pop. 147,595)

Fifty-five miles north of San Francisco, Santa Rosa provides clean air, water and a healthy environment for residents, with its smoke-free public spaces and restaurants. Enhancing these elements, Santa Rosa has implemented California's Build It Green certification program certifying environmentally sound building construction for municipal, commercial and residential sectors. The program's goal is for more than half of all new municipal building starts of over 10,000 square feet to meet or exceed LEED certification requirements. Well equipped with bicycle paths and lanes, Santa Rosa has recently finished a walking and bicycle trail connecting to the Joe Rodota Trail that leads to nearby Sebastopol. And for a novel way to reconnect with nature, stroll among the native California Gray Rush plants in the Snoopy Head labyrinth at the Charles M. Schulz Museum and Research Center.

6. Oakland, CA (score 7.3675, pop. 399,484)

Oakland has taken a progressive stance on renewable energy, adopting a plan to achieve 50% renewable energy by 2017. Now it's turning its attention to food, with the Oakland Food Council setting a goal for 30% of the city's food production to occur within a 100 mile radius. Bringing those goods into the city are six farmer's markets, while seven community gardens help production right at home. With multi-family housing making up most of Oakland's new building, the city's Green Building Ordinance passed in 2005 will encourage them to achieve LEED Silver rating with rebates and permit fast-tracking. To create a denser downtown and reduce pollution from traffic, Oakland is encouraging 10,000 new residents to move into the downtown area where they'll have access to the city's subway, bus and bicycle path systems. The proof is in the pudding, with 20% of Oakland residents commuting by bicycle or public transport.

7. Berkeley, CA (score 7.285, pop. 102,743)

Berkeley's distinguished history as a center of politically progressive thought extends well into the environmental movement, and the city currently boasts the highest number of members of environmental organizations of any city in the U.S. Located on the gorgeous San Francisco Bay, Berkeley shares the Bay Area Rapid Transit (BART) system with neighboring Oakland and San Francisco, linking all three cities in a community where organic rules. Berkeley requires that all new city-owned buildings be built to LEED Silver standards and has created a sustainable development fee on all new permits to pay for the creation of green building guidelines for residential, multi-family and commercial buildings. Nineteen percent of Berkeleyites commute on public transport and besides BART and the bus system, residents also may take advantage of the city's car sharing program. The green thumbed may work the earth at over 20 community gardens, and their children can get a start at Martin Luther King Jr. Middle School's Edible Schoolyard program where students grow, harvest and prepare organic food.

8. Honolulu, HI (score 7.055, pop. 371,657)

Renowned for its clean air and pure water from Oahu's aquifer, Honolulu is among America's healthiest cities, with a mild climate that encourages outdoor activities along the 28 acre Kaka'ako Waterfront park. Although Honolulu draws 89% of its energy from imported oil, Bill Brennan, press secretary to the mayor, notes that 7% of its power is from burning garbage. The city's H Power Plant burns 500,000 tons of waste annually helping cut down on landfilled trash. To further reduce waste, this March Honolulu launched a lawn, garden and tree clippings or "greenwaste" recycling program. "This greenwaste is recycled here on the island," says Brennan. "It goes to Hawaiian Earth Products, which turns it into mulch and compost and provides it to the public for free on the site or packaged and sold in stores." The future looks green as well: By 2007, all new city buildings of over 5,000 square feet must meet LEED Silver standards.

Although the March 2006 sewage spill Honolulu suffered occurred too recently to be taken into account in this year's scoring, The Green Guide will report on the impact it has on the city's environmental health.

9. Huntsville, AL (score 7.035, pop. 158,216)

New to the top 10 list this year, Huntsville has devoted almost a third of its land to green spaces including undeveloped forest and nature preserves, along with public gardens, parks and waterfront. The city-funded Operation Green Team has been remarkably successful in their public education and city clean-ups, enlisting 12,000 volunteers in their 2005 effort to clean and green the city. Thirteen percent of the population commutes by bus while a trolley is available for special events to reduce congestion, helping clean up their air. The hospital possesses its own light rail system to shuttle staff across its grounds. Although Hunstville relies on coal and nuclear power for the majority of its energy mix, homeowners can purchase solar or wind-generated energy through the Tennessee Valley Authority.

The city is also developing a first-of-its-kind industrial park: 100% of all water runoff, says Ben Ferrill, city of Huntsville planner, will be biofiltered with swales, wet ponds and dry ponds. Rooftop runoff is separated from parking and street runoff to capture pollutants on site before they reach the subsurface aquifer.

10. Denver, CO (score 7.0325, pop. 554,636)

"Denver has just completed a five-year plan for its Greenprint Denver sustainable initiative, covering everything from green building to greenhouse gases," says Beth Conover, director, Mayor's Greenprint Denver initiative. Focusing on greenhouse gas reduction, water conservation and quality, waste reduction and increased recycling, Greenprint Denver also has three solar installations under consideration, one of which is now approved and will produce one to two megawatts. A signatory to the U.S. Mayors Climate Protection Agreement, Denver maintains one of the country's largest hybrid municipal fleets. It is also in the midst of completing the nation's largest light rail system, serving the larger metropolitan region and with an anticipated half-million riders daily. Conover notes that the city of Denver has recently created a position for the promotion of green business and has the "largest CO2 based dry cleaning chain in the country, Revolution Dry Cleaning, using waste C02 for a zero greenhouse gas effect." As for green building, Denver currently has 17 LEED-certified buildings and 73 in the process of certification. With clean water and access to skiing, hiking and wilderness nearby, Denver remains a gem in the Rockies.


American cities, in adopting Kyoto Treaty protocols and taking it upon themselves to build green, are putting themselves at the forefront of the environmental movement at a time when some have predicted its death. But like the once predicted death of cities themselves, forecasts for the demise of the green movement have been greatly exaggerated. Should it be any surprise that people prefer to live in healthier cities with more vibrant (and wildlife-filled) surroundings? Not to those who live there -- or even visit.

This article has been reprinted courtesy of The Green Guide. It was first published on April 7, 2006.

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