· Public transportation (local, well-established): Proactive planning of public transportation enables mobility between residential houses and work places (Arbury 2005, Ewing 2008).
· Mixed-used structure (local, speculative): A key structure of the compact city is the mix of work places, residential homes and services in the same place rendering short transport distances and promotes a pleasant and livable inner city (Arbury 2005, Ewing 2008).
· Pro-active government (local, speculative): Proactive government has been identified as a requirement for compact city development since this is not created by market forces. However, all proactive government interventions may not lead to desirable results.
· Infrastructure development (local-regional, well-established). Building of roads, public transportation etc. allows mobility of city inhabitants from the city fringes to inner city and vice versa. Enables automobile use. This creates incentives to live further out from the inner city (Ewing 2008, Arbury 2005).
· Automobile-use (local, regional, well-established). With economic development more and more people afford a car. Infrastructure development, low car and fuel prices enable automobile use (Arbury 2005). Poor public transportation possibilities increase the need of a car.
· Government support. Competition among different cities to attract job and inhabitants through subsidies and urban planning policies, etc. (local-regional, speculative) (Ewing 2008). Low prices on rents/land in the city peripheral to attract new jobs will create feedback mechanisms that lead to sprawling cities.
Important shocks that contribute to sprawling cities include:
· Sudden rush of people to the city due to natural disasters (famines, flooding etc.) (local, regional, speculative), leading to uncontrolled sprawled or slum areas.
The main external indirect driver that has contributed to sprawling cities includes:
· Urbanization (local, regional, well-established). The desire to live within the city contributes to people moving from rural areas to urban areas. Population growth can also contribute to the welfare of a city, increasing economic development and work opportunities.
The main slow internal indirect driver that has contributed to sprawling cities includes:
· Population growth within the city (local, well-established). Drives the perceived need for inexpensive housing, security and aesthetic quality found in the outskirts of the city.
The main slow internal direct drivers that contribute to sprawling cities include:
· Housing preferences (local-regional, well-established). When cities become overcrowded and expensive people move to the outskirts of the city. There they can find a house less expensive and more spacious (Arbury 2005).
· Increasing crime rates (local, regional, well-established). Many cities increasing in population tend to become unsafe with high crime rates. People decide to live in the outskirts where it often is safer.
· Changing aesthetic preferences (local, regional, well-established). People wish to live closer to nature and value aesthetic qualities of the suburban landscape, which contributes to sprawling development patterns (Brown 2006, Arbury 2005).
· Decreasing car and fuel prices (local, regional, global, well-established). The low prices on cars and fuels which we have today facilitate transportation in urban areas.
From compact city to sprawling city
- When suburban lifestyle becomes more preferred than inner-city life: In North American and Australasian cultures, suburban living became a desired lifestyle and sign of wealth, especially amongst middle class inhabitants (Gillham 2002). Such frame of mind will lead people to believe one must be living in suburban area in order to be perceived as successful and well-established.
- When public transportation becomes an inefficient mode of commute compared to private cars: Here, inefficiency is when time saved using a car is greater than the money saved by using public transportation for each individual. Once an individual feel that public transportation is inefficient, he or she will be willing to move further out to the city outskirts.
From sprawling city to compact city
- When investment for public transportation becomes economically viable: In a low density development, it is difficult to find public transportation plans which are profitable. Only when a critical threshold of population density is reached, public transportation becomes economically viable. However, when public transportation is built, it attracts people to move closer to where there is access to public transportation. This provides a positive feedback for further increase in population density.
- Increased fuel prices: A high increase in fuel prices can cause a significant change in people's behavior. However, the shift in fuel prices must be long enough to have a lasting effect on choices and behavior of people.
Although it may take just one or two poorly planned roads to initiate sprawl in cities, reversing the trend requires more than one remedy. Like most regime shifts, return path to the original regime (which in this case is the compact city) will be hysteretic and much more difficult to achieve than the path to sprawl (Scheffer et al. 2001). Most of all, it requires a balanced approach that meet people's economic, social and environmental requirements of moving back to the inner city (EEA 2006).
Therefore points of leverage can be identified in almost all of the drivers and feedback that lead to urban sprawl.
· Providing more affordable mixed used housing in the inner-city (local, speculative): In order to reversethe trend ofpeople moving further out of a city, inner-city must be able to accommodate more people. Although this is fundamental for increasing inner-city population density, this isdifficult to achieve because of the difficulty in changing pre-existing build infrastructure (Arbury 2005). In other words, once a city is built, it is highly resilient to stay in that structure.Incentive should be placed so that vertical expansion of buildings and mixed-use of buildings are promoted and supported. However, regulators should always be on the lookout for 'windows of opportunity'. Brownfield projects and other redevelopment opportunities must be seized so that it can be transformed tomixed use housing or urban green spaces (EEA 2006).
· Higher quality of life in the inner-city (local, speculative): Inner-city must be a safe and pleasant place to live. Efforts to reduce crimeandimprove environmental conditions, such asambientair quality, and noise, and urban aesthetics are vital to motivate people to move back into inner-city. Creating accessibleand connectedurban green spaces will help people to ease their desire to be closer to nature as well as maintaining high biodiversity in the urban environment.
· Better city planning and implementation (local and regional, well-established): Urban sprawl occurs when there is a lack of planning or existing plans, e.g. city zones, are not well executed (EEA 2006). Regulators must be determined to carry out their plans to prevent a city to sprawl. In order to ensure public support for city planning, stakeholder participation should be promoted (EEA 2006). Efforts should also be made to identify any malignant incentives that support urban sprawl such as subsidies and government support for public services for road construction, electricity, water supply, and waste collection for cityperipheral. If full cost is imposed on sprawled areas, it will offsetanyeconomic benefit fromconverting cheap agricultural lands for housing.
· Negative incentive for private automobile use (local and regional, speculative): There should be a clear shift in government spending from investment on roads that lead to the city outskirt to investment on public transportation to improve inner-city mobility (EEA 2006). Finance for new and enhanced public transportation can be raised from redirecting budget for new roads and also by taxing private car users through schemes like city tolls.
· Fundamental paradigm shift (local, regional and national, uncertain): Public needs to welcome and embrace new urbanism so that living in compact cities becomes desirable. This is most difficult task because value system takes the longest to change. However, in order to ensure that regime shift is prevented, paradigm shift must occur.
· Most of the points of leverage are aimed at government regulations that have effect on behavior of private land developers and city dwellers in deciding where to live and how to move within the city. Therefore, the key actors are relevant government agencies and other governance structure.
· However, change on paradigm must occur for most city dwellers in order to be effective.
Ecosystem service impacts
The loss of land caused by sprawl has a negative impact on provisioning services such as food crops, livestock, fisheries, wild animals and plant products, timber, fuel, fibre crops and woodfuel (Ewing 2008; Arbury 2005). Deforestation can also result in poor air quality regulation, which, together with the increased number of automobiles associated with sprawl, is a great problem. Moreover, there is biodiversity loss affecting other regulating services such as pollination, pest control and disease control. What ecosystem services that are affected differ from case to case and depend on the type of land removed in favour of the built environment. Examples of cultural services that are lost are recreation, aesthetic values, knowledge, education and, to some extent, spiritual and religious values. Also here is it possible to say exactly which services that are involved, and the perceived value varies among people and time.
There are negative impacts on ecosystem services with all types of city expansion. What makes sprawl different from compact city development is the greater amount of land exploited. Another factor is that the very structure of sprawl, with non-compact single use development, is made possible by automobiles, causing pollution and consuming large amounts of energy.
Since the consequences of unplanned city expansion and sprawl are considered unsustainable, many governments are now taking action to turn the trend towards a more compact development. This reduces the social and ecological costs mentioned above. Segregation, for example, is something that exists everywhere, but can be less prevalent in the city centre since people there are more exposed to all social classes (EEA 2006). Except for the negative effects of automobiles, city dwellers are often in good physical health since they walk and bike, have access to gyms and usually are more health conscious. On the other hand, living in the constant hustle-bustle of the city could possibly increase stress and has a negative effect on mental health (Dye 2008). When city expansion is made by making the inner city denser, green areas are sometimes removed. This has a big impact on cultural services like recreation and aesthetic values, but it also causes biodiversity loss affecting regulating services such as carbon sequestration and pollination.
The main user groups in the city system are inner-city dwellers, suburban residents, developers and the government. A compact city is favourable for inner city dwellers since it is pedestrian friendly, has a developed network of public transportation and a mixed used structure. It promotes alternative transportation instead of automobile use, which contributes to less pollution and accidents. Also the suburban residents depend on the city centre for work and activities, but they gain more if it is car friendly and not too compact. For the government, population growth is positive in a short perspective, as long as it leads to economic development. However, in the long run, population growth in terms of compact development is preferable since it leads to less cost linked to sprawl, such as segregation, pollution and ecosystem service loss.
Sprawling cities benefits suburban dwellers the most since they get the best of two worlds – access to the city centre and a private owned lot in a safe and nice environment. Inner-city dwellers, on the other hand, have little connection to suburbs and are only exposed to the negative sides of sprawl. Developers possibly prefer sprawl since it is easier, less regulated and cheaper to build on unexploited land than to densify the inner city.
Uncertainties and unresolved issues
1) Possible arguments for discrediting this case as a regime shift:
First of all, it is difficult to define what is sprawled and compact in real cities, as most cities have both attributes. It is possible to identify archetype cities for sprawl and compact, however, there are many cities in the middle of the spectrum and drawing the boundary between the two city regimes is nearly impossible (Ewing et al. 2008). Even comparing North American and European cities, they tend to be spread out across the spectrum of compactness (in terms of population density) (EEA 2006).
Furthermore, it is difficult to define what is desirable. Many agree that sprawl is undesirable. However, some also find it undesirable to be living in an extremely compact city (Arbury 2005). Finding the right balance in the city structure is highly subjective, involving combinations of people's preferences on population density, commuting (mobility) and urban design (Scoffham and Vale 1996).
Second, conducting research on the urban regime shifts is aligned with difficulty. Multiple drivers and feedbacks along with heterogeneity of human values make it difficult to repeat and arrive at the same conclusions if making experiments. In general, regime shifts with social attributes are more complex than ecological regime shifts. This adds to the fact the built environment is hard or takes time to change, which makes this case more of path dependency and less of a regime shift.
Because of the uncertainty in definition and difficulty in testing urban regime shifts it is hard to come to a firm conclusion whether a regime shift has occurred or not.
2) Key delimitations of this paper:
It has simplified the concept of government as a single entity without segmentation across sectors and scales. However, in reality, governments are multiple institutions, and promoting collaboration between different sectors across scale is the key challenge in transforming ideas into a proactive government intervention (EEA 2006).
Our discussion about sprawling city and compact city are based on the assumption of population growth. However, in reality some cities are experiencing stagnation, hence some of the assumptions that we made may not apply to those cities. With a declining population growth in many industrialized countries, further city stagnation is a possible outcome, and therefore, the meaning of a regime shift could look somewhat different. In this paper, we are discussing the shifts towards sprawl or compact city mostly as a result of population growth. Though, if there is no such growth, and there is a proactive government aiming for a regime shift towards a more compact city, could imply that houses in outskirts are left empty and torn down in favor of other types of land use or open green spaces.
We did not elaborate with the concept of social-ecological resilience within cities in this paper. Social-ecological resilience in cities can be of great importance and work as an enhancer when striving for urban sustainability and environmental solutions. This is an area suitable for further research within the field of sprawling and compact cities.