Urban densification is a strategy designed to change the urban form to create more compact, liveable and sustainable cities in Australia. Compact, higher-density cities support the idea of the 20-minute neighbourhood, where people can access their everyday needs within their local area (Victoria State Government, 2017), while also reducing car dependency by promoting public and active transport, thereby reducing greenhouse gas emissions. The provision of additional housing to support anticipated population growth and increased density is mostly occurring via urban renewal and infill development, especially around transport corridors. However, the federal government’s State of the Environment report expressed concern about inadequate planning for urban greening, especially in areas with a high concentration of medium and high-density development, where urban green space is already scarce (Coleman, 2017).
This paper will argue that urban densification exacerbates the uneven distribution of urban green space and leads to a decline in tree canopy cover in lower socio-economic areas of Australian cities, contributing to growing location-based inequality and negative health and wellbeing outcomes. An urban political ecology lens will be applied to analyse the impact of urban densification, focusing on the key themes of spatial inequality, enhanced trajectories and social power relations. A brief literature review will introduce urban political ecology research and its relevance to the power relations that determine unequal access to nature in Australian cities. A Sydney case study and discussion will show existing spatial inequality of urban green space, the power imbalances that drive inequality in urban development and how this situation arose across Australia.
Urban Political Ecology
Political ecology links politics, institutions, development and environmental change (Adger et al., 2001). Historically, political ecology referred to environmental distribution inequality in the Global South, but now with most of the human population living in cities, importance should be given to urban political ecology in cities in the Global North (Keil, 2003). With a view to achieving sustainability, resilience and climate change mitigation, there has been a broader shift towards urban views of political ecology and the relationship between urban, social, ecological and political spheres (Keil, 2020). Urban political ecology examines these complex interconnected relationships, with specific attention given to the processes that create inequality in urban development and nature and how these shape cities (Heynen, 2016). The multi-level power relations between various groups impact the ongoing development and change in urban environments and directions for the future (Swyngedouw & Heynen, 2003).
Three key themes define urban political ecology; spatial inequality, enhanced trajectories and social power relations (Heynen, 2016). Positive environmental change may lead to social and physical benefits for some people, in some areas, but this often has an inverse impact elsewhere (Heynen et al., 2006), creating spatial inequality of benefits. Diverse groups experience environmental change differently, where affluent areas and residents may experience an enhanced positive trajectory whereas marginalised groups may experience a reinforced negative trajectory (Heynen et al., 2006), leading to an increased disparity in the future. Social power relations may be political, cultural or enabled by access to wealth (Heynen et al., 2006). These power relations determine who controls the natural environment and who will, and will not, benefit from these natural resources (Heynen, 2016).
Urban political ecology is a valuable lens through which to view the unequal impacts of urban densification in Australia. The uneven access to green space is a key issue within urban political ecology research (Heynen, 2016) along with the resulting impacts on health and wellbeing. The urban political ecology lens can be used to examine who gains and who loses from environmental changes resulting from urban densification. The purpose is to determine strategies that provide socially inclusive, sustainable outcomes which include just and equitable distribution of nature (Heynen, 2016).
Impacts of Urban Densification in Australia
The Intergovernmental Panel on Climate Change states that cities in the developed world must decarbonise to mitigate climate change and the risks associated with global warming (de Coninck et al., 2018). Urban planning can create compact, pedestrianised cities that reduce car dependency and thus carbon emissions (Newman & Kenworthy, 2015). In response, Australian state and local governments have developed strategic plans outlining targets and strategies promoting climate change mitigation which include urban densification via urban renewal and infill development (Greater Sydney Commission, 2018; Victoria State Government, 2017).
Compact cities create opportunities for sustainable public transport, active transport, avoided journeys, construction of energy-efficient buildings and reduced urban sprawl (Greater Sydney Commission, 2018; Victoria State Government, 2017). The Greater Sydney Commission (2018) is promoting higher-density urban renewal in more established parts of Sydney as well as around transport nodes in growth corridors, while infill development is to take place via what is known as the missing middle, medium-density housing in suburban Sydney. Melbourne is focused on higher-density housing in inner-city neighbourhoods and middle-ring suburbs (Victoria State Government, 2017), with other Australian cities creating strategic plans with similar objectives.
Environmental Impact of Urban Densification
While urban densification can help mitigate climate change, it can lead to a decline in tree canopy cover and green space and an increase in urban heat and health stress (Newton, 2017). Evidence indicates densification is contributing to a loss of urban green space, especially in Australia, and that this loss has unequal impacts determined by socio-economic status (Haaland & van den Bosch, 2015). For example, increased density in Sydney is associated with a decline in both private and public green space, however, higher socio-economic areas have significantly more private greening (Lin et al., 2015). An analysis of infill development in Perth showed a significant loss of mature trees due to the clearance of street trees along with the land to be subdivided (Brunner & Cozens, 2013). Changed planning regulations permitted reduced setbacks for the new dwellings which therefore occupied a greater proportion of the land than previously (Brunner & Cozens, 2013), resulting in a loss of private green space. A reduction in private urban green space due to urban renewal and infill development is rarely countered by the provision of new public green space (Haaland & van den Bosch, 2015). This is a concern in South East Queensland where increased density in inner-city areas has diminished community land available for new parks, gardens and other urban green spaces (Byrne et al., 2010).
Impact of Urban Green Space on Health and Wellbeing
Poor physical health, increased stress levels and mental health issues are associated with urban life (McDonald et al., 2018). However, literature shows proximity to nature contributes to improved health and wellbeing. Access to nature through nature-based solutions can reduce the risk of negative urban outcomes (McDonald et al., 2018). For example, street trees and urban parks can improve air quality and reduce extreme temperatures by filtering fine particulate matter and providing shade (McDonald et al., 2016), thereby reducing morbidity and mortality.
Similar to the idea of nature-based solutions, biophilic urbanism is an urban planning concept which promotes connection with nature to improve mood, alleviate stress and enhance immunity by incorporating nature into building design (Beatley, 2017). For example, Melbourne’s Green Your Laneway program transformed several inner-city laneways by introducing vertical gardens, window boxes and rain gardens while engaging the local community to promote stewardship of the project (Cabanek et al., 2020). This program was shown to positively impact physical and mental health by encouraging a sense of place through outdoor activities and social interaction (Cabanek et al., 2020). However, it is estimated that only 13% of global urban residents have access to nature and the resulting health and wellbeing benefits (McDonald et al., 2018).
Sydney Case Study: Inequality of Urban Renewal
Spatial Inequality of Tree Canopy Cover
Tree canopy cover is unevenly distributed across Greater Sydney. The Greater Sydney Regional Plan refers to three distinct strategic areas within Greater Sydney, the Eastern Harbour City, the Central River City and the Western Parkland City (Greater Sydney Commission, 2018). The Eastern Harbour City is the established, traditional centre of the city, with high levels of existing amenity and green space. Parramatta is the growing centre of the Central River City while Campbelltown is in the Western Parkland City and experiences low rainfall and growing numbers of extreme hot days (Greater Sydney Commission, 2018). The Eastern Harbour City has the highest tree canopy cover of these three areas at 32% while the Central River City and the Western Parkland City have 17% and 16% respectively (Greater Sydney Commission, 2018). The percentage of tree canopy cover is shown in Figure 1, with the affluent Eastern Suburbs, Lower North Shore and Upper North Shore with the highest levels of urban cover. This indicates existing spatial inequality of proximity and access to trees and urban green space, with residents in central and western areas of Sydney the most impacted.
Spatial Inequality of Negative Impacts
On average, residents in the Central River City and the Western Parkland City are lower socio-economic households in comparison the those in the Eastern Harbour City. For example, using household income as an indicator of socio-economic status, the median weekly household income in Parramatta is $1,759 and in Campbelltown, it is $1,459, whereas in the Eastern Harbour City area of Ku-ring-gai it is $2,640 (Australian Bureau of Statistics, 2016). The median weekly rent in Ku-ring-gai is $650 per week (Australian Bureau of Statistics, 2016) which is unaffordable for lower-income households due to rental stress, a situation which occurs when rent is more than 30% of household income. A lack of affordable housing limits the mobility of lower socio-economic households, thereby reducing access to greener areas.
Residents in central and western Sydney are also more likely to rent their dwellings with rental tenure rates in Parramatta, Campbelltown and Ku-ring-gai being 41.4%, 32.9% and 17.5% respectively (Australian Bureau of Statistics, 2016). Tenure type contributes to a lack of private tree cover. As an insecure tenure type, rental households lack an incentive to plant trees as they are unlikely to benefit in the time it takes for the trees to mature (Perkins et al., 2004) and renters may also lack the capacity to invest in tree planting. Conversely, high levels of home ownership in more affluent areas encourages more private tree planting and therefore increased tree canopy in already green areas. Western Sydney has been identified as an area of disadvantage and greening strategies have been put in place (Bunker, Freestone, et al., 2017), however at present, lower socio-economic households do not have sufficient access to or benefits from trees where they live.
Social Power and Uneven Urban Densification
Densification is taking place across Greater Sydney, but Figure 2 shows a disproportionate amount of urban renewal planned for Parramatta and Campbelltown, with limited renewal planned for the Eastern Harbour City.
Campbelltown will potentially construct 17,900 additional urban renewal dwellings by 2040 with a target of 6,800 in the next five years (Campbelltown City Council, 2020), whereas Ku-ring-gai council recently voted against increasing building heights and new zonings which would provide increased housing capacity (Ku-ring-gai Council, 2020a). Ku-ring-gai council projects future housing needs in the area to be 10,704 dwellings by 2036 but has only committed to providing 3,000 to 3,600 additional dwellings, citing overwhelming community resistance to further development (Ku-ring-gai Council, 2020b). As one of the wealthiest local councils in Sydney, residents have significant resources to block strategies suggested by the Greater Sydney Commission and in 2011, residents opposed to planning reform successfully took legal action against the NSW Government (Ruming & Houston, 2013), action which may be inaccessible in less affluent areas. Ku-ring-gai’s affluent residents will benefit by retaining urban green space which might have otherwise been lost during development, whereas Campbelltown’s residents may see a decline in green space.
It is argued that urban planning in Sydney, including the distribution and nature of development, is now driven by market forces rather than metropolitan strategic planning (Troy et al., 2020). Private developers are expected to deliver the majority of renewal projects in Sydney, giving them significant power and control over building design and inclusion of green amenity, which may not benefit the wider public (Ruming, 2018b). For example, large-scale urban renewal projects have previously seen social and low-income housing as well as public green space being removed to make way for high-end apartments, effectively pushing out marginalised residents and privatising urban space (Ruming, 2018a). Without adequate regulations and planning for increased tree canopy cover and urban green space, increased densification risks reduced proximity, access and connection to nature and a reinforced negative trajectory for lower socio-economic groups.
Urban Political Ecology and Densification
Growing Location-based Inequality
As well as spatial inequality, urban political ecology considers what is known as enhanced trajectories, where privileged groups experience improved conditions, while the experience of marginalised or lower socio-economic groups worsens. This has been the case in Australia as higher levels of densification is occurring in lower socio-economic areas, leading to a decline in urban green space where tree cover and green space is already limited. As a higher proportion of residents in affluent areas are home owners, they have the capacity to increase tree cover by planting trees on their property and may also experience improved wellbeing from frequent exposure to nature (Mavoa et al., 2019). Meaning affluent neighbourhoods maintain higher levels of urban green space, have the potential to increase greening and therefore experience an enhanced positive trajectory.
Governance and Social Power Relations
In Australia, neoliberal ideology and insufficient state government funding have shifted development control from the public to the private sector. Anticipated population growth requires additional infrastructure and housing supply, but state governments lack the funding capacity for adequate provision, instead relying on public-private partnerships and the private sector (Bunker, Crommelin, et al., 2017; Pinnegar et al., 2020). Consequently, government planning authorities lost power to developer, financial and investor interests who invest for profit-seeking rather than securing a place to live and achieving equitable outcomes (Pinnegar et al., 2020). Resident and community power and influence has been weakened by developer control, contributing to widening spatial inequality (Newton & Frantzeskaki, 2021).
Growing executive power shifts further planning and development control towards corporations. Increasing ministerial power allows state governments to remove planning control from local governments by deeming projects state significant (Bunker, Crommelin, et al., 2017) and forming public-private partnerships. This allows corporations to plan and negotiate project deliverables directly with the relevant minister, potentially creating conflicts of interest and undue influence in decision making (Bunker, Crommelin, et al., 2017), often at the expense of urban green space. As an example, Sydney’s Barangaroo development was deemed state significant, where a public-private partnership shares profits between the state government and the private developer (Searle, 2020). It is suggested this influenced the state government to alter initial plans by permitting increased density and the construction of a casino in order to receive higher profits and taxes (Searle, 2020). Despite significant public opposition, this additional construction occurred on land designated for open green space (Searle, 2020), detrimental to residents, the wider public and the natural environment. Coupled with the financial power provided to affluent residents, as discussed in the Sydney case study, urban residents are experiencing inequitable outcomes due to considerable power imbalances.
Spatial inequality should be directly acknowledged and addressed in urban planning and should avoid further privileging affluent neighbourhoods (Haase et al., 2017). Equitable distribution of social power and inclusion can reduce spatial inequality (Heynen, 2016) and address uneven access to green space. This can be achieved by implementing multi-actor governance, meaning the design, implementation and management of urban planning and greening involves all tiers of government, community organisations and residents (Kabisch et al., 2017). Mandatory inclusionary zoning in urban renewal developments can address inequality by requiring a proportion of dwellings to be affordable for low-income households (Ruming, 2018b), providing marginalised groups access to established green areas. The challenges concerning growing executive power and developer control should be examined (Bunker, Crommelin, et al., 2017).
Australian cities are using urban densification as a climate change mitigation strategy. However, this has unintended negative consequences for lower socio-economic groups. Spatial inequality exists in Australian cities with respect to tree cover and access to green space along with associated health and wellbeing impacts. This inequality is being exacerbated by urban renewal and infill development which leads to further uneven greening. Due to wealth inequality and neoliberal policies which place control of renewal predominantly in the hands of the private sector, densification disproportionately impacts lower socio-economic groups who lack the power to influence outcomes.
Strong multi-level governance, institutions and urban planning are required to reduce inequality while transforming our cities to mitigate climate change (de Coninck et al., 2018). Tree canopy cover, urban green spaces and nature-based solutions need to be evenly distributed throughout cities and must be accessible and beneficial for diverse groups (Haase et al., 2017). Pressure from other land uses means dense urban areas typically have limited space for integrating the natural environment (Thomson & Newman, 2021), however, a sustainable planning approach that combines urban design and governance with community engagement can progress change (Newton & Frantzeskaki, 2021). Additionally, biophilic urbanism can be implemented within urban renewal project designs to integrate greening in and over buildings (Thomson & Newman, 2021).
Climate change action needs to consider the impacts on diverse groups and address potential unintended consequences. Policy should focus on multi-level and multi-actor governance with the intention of diversifying interests and control of development. Urban planning regulations should be reviewed and strengthened for the purpose of increasing greening in urban renewal and infill developments as well as ensuring mandatory inclusionary zoning throughout cities. Potential areas for future research include examining the impact of greening strategies on lower socio-economic communities, challenges to urban green space conservation, nature-based solutions to inequality and barriers to implementing these solutions.