Eco-cities

From Wikipedia, the free encyclopedia
Jump to: navigation, search

An eco-city is a city built off the principles of living within the means of the environment. The ultimate goal of many eco-cities is to eliminate all carbon waste, to produce energy entirely through renewable sources, and to incorporate the environment into the city; however, eco-cities also have the intentions of stimulating economic growth, reducing poverty, organizing cities to have higher population densities, and therefore higher efficiency, and improving health.

History[edit]

History

Origins[edit]

The concept of the “eco-city” was born out of one of the first organizations focused on eco-city development, “Urban Ecology.” The group was founded by Richard Register in Berkeley, California in 1975,[1] and was founded with the idea of reconstructing cities to be in balance with nature.[2] They worked to plant trees along the main streets, built solar greenhouses, and worked within the Berkeley legal system to pass environmentally friendly policies and encourage public transportation. Urban Ecology then took the movement another step further with the creation of The Urban Ecologist, a journal they started publishing in 1987.

International Eco-City Conference[edit]

Urban Ecology further advanced the movement when they hosted the first International Eco-City Conference in Berkeley, California in 1990.[3] The Conference focused on urban sustainability problems and encouraged the over 700 participants to submit proposals on how to best reform cities to work within environmental means. There have since been eight more International Eco-City Conferences in Adelaide, Australia; Yoff, Senegal; Curitiba, Brazil; Shenzhen, China; Bangalore, India; San Francisco, United States; Istanbul, Turkey; and Montreal, Canada.[4]

Eco-City Criteria[edit]

There are currently no set criteria for what is considered an “eco-city,” although several sets of criteria have been suggested, encompassing the economic, social, and environmental qualities an eco-city should satisfy. The ideal “eco-city” has been described as a city that fulfills the following requirements:[2][5]

An example of a green roof project
  • Operates on a self-contained economy, resources needed are found locally
  • Has completely carbon-neutral and renewable energy production
  • Has a well-planned city layout and public transportation system that makes the priority methods of transportation as follows possible: walking first, then cycling, and then public transportation.
  • Resource conservation—maximizing efficiency of water and energy resources, constructing a waste management system that can recycle waste and reuse it, creating a zero-waste system
  • Restores environmentally damaged urban areas
  • Ensures decent and affordable housing for all socio-economic and ethnic groups and improve jobs opportunities for disadvantaged groups, such as women, minorities, and the disabled
  • Supports local agriculture and produce
  • Promotes voluntary simplicity in lifestyle choices, decreasing material consumption, and increasing awareness of environmental and sustainability issues

In addition to these initial requirements, the city design must be able to grow and evolve as the population grows and the needs of the population change.[6] This is especially important when taking into consideration infrastructure designs, such as for water systems, power lines, etc. These must be built in such a way that they are easy to modernize (as opposed to the dominant current strategy of placing them underground, and therefore making them highly inaccessible).

Each individual eco-city development has also set its own requirements to ensure their city is environmentally sustainable; these criteria range from zero-waste and zero-carbon emissions, such as in the Sino-Singapore Tianjin Eco-city project and the Abu Dhabi Masdar City project, to simple urban revitalization and green roof garden projects in Augustenborg, Malmö, Sweden.[7][8][9][10]

Using a different set of criteria, the International Eco-Cities Initiative recently identified as many as 178 significant eco-city initiatives at different stages of planning and implementation around the world.[11] To be included in this census, initiatives needed to be at least district-wide in their scale, to cover a variety of sectors, and to have official policy status.

Practical Achievements[edit]

Economic Impact[edit]

One of the major and most noticeable economic impacts of the movement towards becoming an eco-city is the notable increase in productivity across existing industries as well as the introduction of new industries, thus creating jobs.

First, the movement away from carbon-producing energy sources to more renewable energy sources, such as wind, water and solar power, provides local economies with new, thriving industries. The creation of these industries, in turn, births an increase in the demand for labor; thus, not only does total employment increase, but an increase in wages also mimics increasing employment.[12]

Moreover, one of the main priorities of a sustainable city is to reduce its ecological footprint by reducing total carbon emissions, which, economically speaking means increasing productivity. Merely increasing the rate of productivity in an industry reduces costs, both monetary and environmental; that is, as an industry becomes more productive, it can more efficiently allocate and use both its physical and human capital, reducing the time it takes to make the same amount of goods which also allows for a higher wage (because employees are doing more) and a lesser environmental impact (because using less energy and resources to produce the same amount).[12]

In all, although the initial movement towards becoming a sustainable city may be quite costly for a smaller, poorer city, the benefits of such movement are plentiful in the long-run economic model. Moreover, as more and more countries move towards becoming more sustainable, the technologies required to initiate this movement will become more readily accessible and cheaper; therefore, many rich, developed nations should put themselves forth as an example of what other cities should model themselves like, thus sparking the innovation towards a future of sustainable technology.

Environmental Standards[edit]

Although local environmental standards may differ across eco-cities, each city nonetheless has its own appropriate and practical goals and expectations that have provided the foundation for their recognition as a sustainable city. Differences in these goals and expectations are to be expected, however, due to the limitations of technology and local financing.

The primary goal for all sustainable cities is to significantly decrease total carbon emissions as quickly as possible in order to work towards becoming a carbon-free city; that is, sustainable cities work to move towards an economy based solely on renewable energy. Actions towards carbon-reductions can be seen on both the corporate and individual levels: many industries are working towards cleaner production, but individuals are also moving away from environmentally costly forms of transportation to more sustainable methods, such as public transportation or biking. On this note, another common environmental goal is to increase and make more efficient the public transportation systems.

Many sustainable cities also work towards becoming more densely populated (urban density); having its citizens living closer to energy production means less environmental costs of transporting said energy to citizen households. Additionally, citizens living closer to the city-center also mean that transportation to work is significantly reduced.[13]

Oftentimes, a city’s primary goal is to increase environmental education in hopes of achieving better citizen involvement and cooperation. By making the private sector more aware of how its behavior affects the environment, a reduction in carbon emissions becomes more of a reality.

In terms of international standards, however, we can look to the International Finance Corporation (IFC). The IFC has a long history of implementing environmental and social standards in localized economies, and its primary mission is to promote sustainable development across the globe, primarily in developing countries. One of its plans to accomplish this goal is to encourage international cooperation in order to accelerate and promote sustainable growth across nations.[14]

Overall, the most important aspect of setting an environmental goal is making it plausible. Many cities across the globe set goals that, although they may be super-sustainable, are not entirely possible. These over-exaggerated goals include too much sustainable development for a small time period or an expectation that is simply too expensive. The globe needs to work together to make steps towards a sustainable future that are possible and execute them well, ultimately resulting in an overall spiral towards complete global sustainability.

Social[edit]

Poverty Reduction[edit]

The development of eco-cities has aided in reducing poverty in various locations via job creation in environmentally friendly business sectors. By promoting social equity based on meeting the needs of local populations, eco-cities create sustainable business models that encourage local investment and the subsequent expansion of the job market. Johannesburg, South Africa serves as a prime example of the manner in which adopting eco-city standards can aid in reducing urban poverty. According to the United Nations Environment Program, the “EcoCity [program] has mobilized the disadvantaged and unemployed people of Ivory Park (part of the city of Johannesburg) to form co-operatives to grow and buy food, to recycle, to repair bicycles, to build homes, to use and promote green energy solutions, to become eco-tourism guides and more than 300 jobs have been created” between 1991 and 2001.[15] By creating small local businesses, residents of eco-cities create self-sufficient small enterprises that, as an aggregate, greatly alleviate the scarcity of quality employment and create economic opportunities that continuously aid in poverty reduction. These ecologically sound small-scale practices are additionally less sensitive to economic shocks, allowing for enduring economic sustainability in eco-cities. In addition to creating green jobs, eco-cities promote the deployment of green methods of saving money, such as investing in ecologically sustainable local infrastructure, carpooling, and reducing consumption of water and energy, to decrease the financial burden on the poor.[16]

Population Distribution[edit]

Increasing proportions of the world population are now located in cities. As a result, eco-city models place substantial attention on mitigating and reducing the environmental damage caused by growing urban populations.[17] Because urbanization does not appear to be slowing, eco-cities aim to increase urban density while integrating “green infrastructure” or "green spaces" into the urban landscape. Eco-cities promote compact use of land by people for residential and commercial purposes. In this way, increasing urban density reduces the strain on the environment by centralizing and, thereby, reducing resource consumption. For example, the 2006 plans for the Chinese eco-city of Dongtan employed this strategy.[18] At the time, the city planned to divide its residential and commercial land into three compact districts divided by farms, parks, lakes, and pagodas. Additionally, residents would live in ecologically designed apartment buildings six to eight stories high but appropriately spaced apart as to avoid heat island effects. Although no construction of Dongtan has happened yet, these principles are generally applicable to all eco-cities.[19]

Furthermore, increased urban density reduces urban sprawl, thus, decreasing dependence on cars. According to Kenworthy, urban density is accountable for 84% of the variance in car travel.[20] Because of the compact urban layout of eco-cities, residents are able to easily navigate their surrounding environment on foot, by bicycle, or through use of public transportation. As a result, eco-cities avoid much of the negative effects of car pollution.

Additionally, by centralizing the population within a given area, eco-cities increase the amount of land that can be used for parks and urban agriculture. As such, eco-cities increase food security and promote ecological preservation within urban areas. Urban agriculture allows for “production of fresh food and vegetables, reduction on transportation load and enrichment of environmental quality” (Lim 2010).[21]

Public Health[edit]

Eco-cities aid in creating healthier urban populations through the implementation of sustainable practices that improve environmental standards and, as a result, decrease the strain on public health. By employing practices that aim to reduce air pollution, eco-city standards have an indirect effect on decreasing rates of respiratory disease within urban areas. According to the World Health Organization, urban outdoor air pollution is responsible for over 1.3 million deaths worldwide per year. Additionally, “the mortality in cities with high levels of pollution exceeds that observed in relatively cleaner cities by 15–20%."[22] Through the implementation of “clean” practices, eco-cities greatly assist in decreasing the disease burden placed on urban residents by decreasing the risk factors associated with cardiovascular and respiratory diseases as well as various forms of cancer.

Additionally, the “greenspaces” that constitute the infrastructure of eco-cities provide a unique method of reducing air pollution and promoting clean air. Urban foliage naturally cleans the air by absorbing carbon monoxide, nitrogen dioxide, and sulfur dioxide. Green spaces also absorb airborne particulates and reduce heat, allowing for improved levels of public health.[23]

The decreased dependency on cars encouraged by the compact, walkable layout of eco-cities will also help combat obesity and other chronic diseases by encouraging frequent physical activity. The World Health Organization estimates that physical inactivity leads to 3.2 million deaths per year. 2.6 million of these deaths are centralized in low and middle-income countries.[22] Thus, by reducing urban sprawl, eco-cities may help decrease rates of coronary heart disease and stroke, diabetes, hypertension, colon cancer, breast cancer, osteoporosis, and depression. Furthermore, by decreasing the concentration of cars within city limits, eco-cities are also able to reduce the number of preventable deaths among the working age population. It is estimated that traffic accidents kill 1.2 million people per year and is the leading cause of death among people under the age of 25 (WHO, 2011).[22]

Increased access to affordable vegetation via urban agriculture also permits the improvement of public health conditions by making healthy foods more available and affordable. Lye and Chen note, “An eco-city must not become or be perceived as an enclave for only the rich and powerful but must welcome and be accessible to people from various walks of life."[21] By investing in urban agriculture, eco-cities can help eliminate the prominent issue of food deserts in urban poor areas. Expanded access to vegetables will in hand aid in decreasing rates of obesity, cancer, cardiovascular disease, diabetes and other chronic illness, especially among low-income residents.[22]

Technology and urban layout[edit]

Transportation[edit]

By decreasing urban sprawl, eco-cities decrease the residential and commercial dependence on automobiles. Concurrently, improved public transportation further decreases the demand for cars. The development of metro station and light rail transit systems provide mass transit not only within sectors of a city but between cities.[19] Furthermore, many eco-cities are employing expanded “clean” bus routes in order to decrease the emissions from single household vehicles. Critics note, however, that the high price of “clean” diesel, CNG/LNG, hybrid electric buses, and super capacitor-powered buses may not prove “economically and operationally viable” (World Bank, 2009).[19]

Urbanism[edit]

Jakriborg in Sweden, started in the late 1990s as a new urbanist eco-friendly new town near Malmö

Eco-cities may also seek to create sustainable urban environments with long-lasting structures, buildings and a great liveability for its inhabitants. The most clearly defined form of walkable urbanism is known as the Charter of New Urbanism. It is an approach for successfully reducing environmental impacts by altering the built environment to create and preserve smart cities which support sustainable transport. Residents in compact urban neighborhoods drive fewer miles, and have significantly lower environmental impacts across a range of measures, compared with those living in sprawling suburbs.[24] The concept of Circular flow land use management has also been introduced in Europe to promote sustainable land use patterns that strive for compact cities and a reduction of greenfield land take by urban sprawl.

In sustainable architecture the recent movement of New Classical Architecture promotes a sustainable approach towards construction, that appreciates and develops smart growth, walkability, architectural tradition and classical design.[25][26] This in contrast to modernist and globally uniform architecture, as well as opposing solitary housing estates and suburban sprawl.[27] Both trends started in the 1980s.

Landscape[edit]

Eco-cities primarily employ green roofs, vertical landscaping, and bridge links as methods of decreasing the environmental impact of land use. Constructing green roofs and investing in vertical landscaping create natural insulation for residential and commercial properties as well as allows for rainfall collection. Additionally, green roofs and vertical landscaping lower urban temperatures and help prevent the heat island effect. Bridge links allow for development of a walkable city without disrupting the soil to run utility lines by connecting buildings with above ground walkways.[28]

Energy[edit]

London skyscraper with integrated wind turbines

Eco-cities look to employ renewable energy sources, such as wind turbines, solar panels, and biogas, to reduce emissions. Wind turbines present the opportunity of being able to provide both localized districts within eco-cities and the larger region as a whole with emission-free renewable energy that can additionally supplement existing power sources. Furthermore, by designing buildings with natural ventilation systems, eco-cities reduce the need for air conditioning, thus, drastically decreasing commercial and residential energy use.[28]

Many eco-cities additionally look to deploy solar thermal energy. By installing solar collectors, developers will be able to provide hot water for space heating and individual and community needs while reducing dependence on gas fueled boilers. While solar thermal energy appears to be a more efficient source of renewable energy, many urban planners also view photovoltaics as a viable source of energy. Photovoltaics directly convert solar energy into electricity; however, the extensive costs associated with developing this technology on the city-scale may limit its use when compared to its potential payback.[28] Biogas technology is also deployed as a source of renewable energy as the organic material from wastewater is converted into fuel.[29]

Water[edit]

Eco-cities aim to decrease water consumption by employing technologies that reduce the amount of water that is needed for irrigation and sewage flow while also preventing blackwater and greywater runoff from entering ground water sources. Developers suggest installing low flow fixtures, rainwater harvesting systems, and sustainable urban drainage systems to meet eco-city standards. Additionally, advanced irrigation systems (xeriscaping) aid in maintaining green infrastructure while decreasing green space consumption of water for irrigation.[28]

Leading Eco-cities[edit]

Curitiba, Brazil[edit]

The city of Curitiba, Brazil proactively began to address the challenges of sustainable urban development in 1966 with a master plan that outlined future integration between urban development, transportation and public health.[30]

This plan has been realized in modern Curitiba, which is defined by linear stretches of urban development surrounded by green space and low-density residential areas.[30] The city was designed for the mobility of people, not the mobility of cars. The city’s bus system is highly developed, with high-capacity busses and dedicated lanes, it effectively reaches about 90% of the population.[30] This bus system is utilized by 45% of the population, which has caused private automobile use to drop to 22%.[30] Despite this decline, to prevent congestion central areas of the city have been closed to cars. These road closures have led to dynamic economic growth for local shops and the development of community space for pedestrians.[30]

Linear urban development in Curitiba contrasted with surrounding residential development

The resulting public health and education gains from this initiative have also been substantial. Curitiba maintains the lowest air pollution rates in Brazil and over 300,000 trees in the city helps reduce natural flooding.[30] Curitiba has also dedicated resources to environmental education in primary school, which has translated into environmentally conscious citizens. Over 70% of city residents participate in recycling programs which fuels the city’s progressive waste processing system.[30]

Curitiba has maintained a consistent vision of the future and worked to attain it by through careful urban planning that takes into account transportation, while also encouraging environmental initiatives and public health. In 2010, Curitiba recognized for their achievement with the Globe Sustainable City Award due to “their understanding of sustainable city development – both regarding policy and implementation.”[31]

Auroville, India[edit]

Auroville was founded in 1968 with the intention of realizing human unity, and is now home to approximately 2,000 individuals from over 45 nations around the world. Its focus is its vibrant community culture and its expertise in renewable energy systems, habitat restoration, ecology skills, mindfulness practices, and holistic education.

Freiburg, Germany[edit]

The city of Freiburg, Germany, whose sustainable policies date all the way back to the 1970s, has constructed itself as a sustainable city by actively committing to its target areas of energy, transportation, and to its three pillars for sustainable development: energy saving, new technology, and renewable energy sources.[32] One of the largest motivators for success can be accredited to citizen’s engagement; in the 1970s a local nuclear power opposition lead to the creation of a campaign for sustainable solutions to the energy needs of the city. A network of environmentalists, research organizations, and businesses were established, helping the agenda of a sustainable city push forward.[32]

Taking advantage of Freiburg’s location, educated and active residents, and political priorities invested in the environment and economy has led Freiburg to be considered a Solar Capital.[33] Along with high solar electricity rates,[32] Freiburg hosts such innovations as the world’s first football stadium with its own solar power plant and the world’s first self-sustaining solar energy building.[33] In terms of both ecology and economy, Freiburg has been extremely successful in the fields of research and marketing of renewable energy. The Freiburg science network and solar industry embraces many research institutions, like the Fraunhofer Institute for Solar Energy Systems ISE, Europe’s largest solar research institute.

In addition to solar initiatives, over the last four decades Freiburg has made improvements to their transportation systems. Freiburg has over 500 km of bicycle paths and more than 5000 bicycle parking spaces as well as car-free centers, 30 kph zones, a region wide bus service, and tram lines.[32]

Long before it was taken seriously Freiburg was resolving to cut carbon dioxide emissions. In 1966, the city resolved to lower carbon dioxide by 25 percent by 2010. Although they did not reach their initial goal by 2010, they are continually extending their goals. By 2030, they resolved to cut carbon dioxide emissions by 40 percent and be climate neutral by 2050.[33]

Freiburg also focuses initiatives on waste management. Paper products are composed to 80 percent recycled materials. Financial incentive programs, like discounts for collective waste disposal and people who compost, are used to increase waste avoidance. Since 2005, Freiburg’s non-recyclable waste has been incinerated and the heat energy released is converted to supply electricity to almost 25,000 households in the city.[33]

Freiburg is a green city. 43 percent of borough area is woodland. In 2001, the Freiburg Woodland Convention was adopted and since 2009, the city officially supported the Freiburg Convention on the Protection of Ancient Woodland. For over 20 years Freiburg has worked to maintain their public parks with principles that work with nature: they no longer use pesticides, grass is mown less, and almost 50,000 trees line streets and parks.[33]

Stockholm, Sweden[edit]

Stockholm in Sweden has been an environmentally focused city that is redeveloping itself to become an eco-city through efficient urban planning and resource use. Stockholm has established six environmental goals, called Vision 2030, that act as the foundation of this initiative. These goals include development of efficient transportation, sustainable energy, land, and water use, waste treatment improvements, and safe building and product materials.[30] Beyond Vision 2030, Stockholm is planning to be fossil fuel free by 2050.[30]

In terms of urban planning, Stockholm currently requires mandatory reuse of land before urban sprawl can continue.[30] This policy has led to complete revitalization of run-down and abandoned industrial areas that have been transformed into modern, efficient and integrated residential and business communities.[30] The Hammarby Sjostad district of Stockholm is the primary example of this practice, as this resurrected industrial area has become twice as energy efficient as the rest of the city after an environmentally focused redevelopment.[30]

These gains are measured by the environmental load profile of the area, a life-cycle assessment tool developed by the City of Stockholm, the Royal Institute of Technology, and a consultancy firm.[30] This unique measure allows for environmental performance analyses, on both the small and large scale, in terms of environmental costs and benefits.[30] This comprehensive measure has allowed Stockholm to quantify their environmental progress and could be applied as a decision-making tool in other cities or districts to aid their environmental efforts.[30]

Stockholm has pursued green development and optimization of urban systems and achieved results. These efforts were recognized in 2010 by European Union, which deemed Stockholm the European Green Capital for “leading the way towards environmentally friendly urban living.”[34]

Challenges[edit]

Despite the sustainability, efficiency and other established benefits of ecocities, actual implementation can be difficult to attain. Existing infrastructure, both in terms of the physical city layout and existing local bureaucracy, are major, often insurmountable, obstacles to large-scale sustainable development.[17] The high cost of the technological integration necessary for eco-city development is a major challenge, as many cities either can’t afford, or are not willing to take on, the extra costs.[30]

Challenges associated with planning and managing sustainable programs are also large. Cities that want to become more sustainable are faced with retrofitting existing structures and concurrent management of sustainable urban expansion and development. The costs and infrastructure needed to manage these large scale, two-pronged projects are great, and beyond the capabilities of most cities.[30] In addition, many cities around the world are currently struggling to maintain the status quo, with budgetary issues, high rates of poverty, transportation inefficiencies, and rapid population growth encouraging reactive, coping policy.[30] While there are many examples worldwide, the development of ecocities is still limited due to the vast challenges and high costs associated with sustainability.

References[edit]

  1. ^ "Urban Ecology". Retrieved 21 November 2011. 
  2. ^ a b Roseland, Mark (1997). "Dimensions of the Eco-city". Cities 14 (4): 197–202. 
  3. ^ Devuyst, Dimitri (2001). How green is the city?. New York: Columbia University Press. 
  4. ^ "Ecocity Builders". Retrieved 21 November 2011. 
  5. ^ Harvey, Fiona. "Green vision: the search for the ideal eco-city". Financial Times. Retrieved 21 November 2011. 
  6. ^ Graedel, Thomas. "Industrial Ecology and the Ecocity". National Academy of Engineering. Retrieved 21 November 2011. 
  7. ^ Caprotti, F. (2014) 'Critical research on eco-cities? A walk through the Sino-Singapore Tianjin Eco-City'. Cities 36: 10-36.
  8. ^ Yoneda, Yuka. "Tianjin Eco City is a Futuristic Green Landscape for 350,000 Residents Read more: Tianjin Eco City is a Futuristic Green Landscape for 350,000 Residents | Inhabitat - Green Design Will Save the World". Inhabitat. Retrieved 21 November 2011. 
  9. ^ Palca, Joe. "Abu Dhabi Aims to Build First Carbon-Neutral City". NPR. Retrieved 21 November 2011. 
  10. ^ "Ekostaden Augustenborg". World Habitat Awards. Retrieved 21 November 2011. 
  11. ^ Joss, S., Tomozeiu, D. and Cowley, R., 2011. "Eco-Cities - a global survey: eco-city profiles", University of Westminster (ISBN 978-0-9570527-1-0). Available from: https://www.westminster.ac.uk/ecocities/publications
  12. ^ a b Gerber, James (2010). International Economics. Prentice Hall. pp. 167–175. ISBN 978-0-13-510015-8. 
  13. ^ "Eco-Cities". Good Planet. Retrieved 20 November 2011. 
  14. ^ "International Finance Corporation's Policy on Social and Environmental Policy". International Finance Corporation. Retrieved 20 November 2011. 
  15. ^ "Eco-City, Johannesburg". United Nations Environment Program. Retrieved 17 November 2011. 
  16. ^ "CSR Best Practices- Eco-City: Johannesburg, South Africa". Article 13. Retrieved 17 November 2011. 
  17. ^ a b "Eco2 Cities". World Bank. Retrieved 16 November 2011. 
  18. ^ Pearce, Fred. "Eco-cities Special: A Shanghai Surprise". New Scientist Tech. Retrieved 17 November 2011. 
  19. ^ a b c "SIno-Singapore Tianjin Eco-City: A Case Study of an Emerging Eco-City in China". World Bank. Retrieved 17 November 2011. 
  20. ^ Kenworthy, Jeffrey. "The eco-city: ten key transport and planning dimensions for sustainable city development". Retrieved 17 November 2011. 
  21. ^ a b Fook, Lye Liang (2010). Towards a Liveable and Sustainable Urban Environment: Eco-cities in Asia. Singapore: World Scientific. ISBN 978-981-4287-76-0. 
  22. ^ a b c d "Air quality and health". World Health Organization. Retrieved 18 November 2011. 
  23. ^ "Towards a Green Economy". United Nations Environment Program. Retrieved 17 November 2011. 
  24. ^ Ewing, R "Growing Cooler - the Evidence on Urban Development and Climate Change". Retrieved on: 2009-03-16.
  25. ^ Charter of the New Urbanism
  26. ^ "Beauty, Humanism, Continuity between Past and Future". Traditional Architecture Group. Retrieved 23 March 2014. 
  27. ^ Issue Brief: Smart-Growth: Building Livable Communities. American Institute of Architects. Retrieved on 2014-03-23.
  28. ^ a b c d "Ecocity: The Energy Concept". Ecocity. Retrieved 18 November 2011. 
  29. ^ "Purac launches new biogas technology for Eco-city in China". Lackeby Water Group. Retrieved 18 November 2011. 
  30. ^ a b c d e f g h i j k l m n o p q r Hiroaki Suzuki; Arish Dastur; Sebastian Moffatt; Nane Yabuki; Hinako Maruyama (2010). Eco2 Cities: Ecological Cities as Economic Cities. World Bank Publications. p. 170. 
  31. ^ "Globe Award". Retrieved 20 November 2011. 
  32. ^ a b c d "Freiburg in a pathway towards a sustainable city". Gaia Consulting. Retrieved 20 November 2011. 
  33. ^ a b c d e "Green City-Freiburg". Retrieved 20 November 2011. 
  34. ^ "European Green Capital". City of Stockholm. Retrieved 20 November 2011.