Abstract: The urban heat island effect, in which cities are hotter than surrounding rural areas, will be exacerbated by climate change impacts for many Australian cities. Heatwaves already kill more people than other natural disasters, and have significant impacts on productivity and liveability. Vegetation is one of the most effective mitigation options for the urban heat island effect. However, in many Australian cities, green space is under increasing pressure from urban densification and sprawl. To date, green space planning has a relatively weak role in urban planning, and the links between urban planning and provision of urban green space, and its broader urban liveability contributions, are largely missing.
This paper provides an overview of the urban heat island effect, and urban greenery’s role in its mitigation. Following this, it presents an analysis framework to assess the effectiveness of Australian policies in retaining and maximising urban greenery. The framework utilises research on sustainability transitions to structure the criteria for analysing policies. The framework focuses on policy processes and content to assess policy effectiveness and to define policy ‘success’. We propose that a key component of policy effectiveness is gaining cross-organisational ‘ownership’ and agency for policy implementation from across multiple departments within the policy’s jurisdiction. Reflecting urban greenery’s multi-functionality, we propose that policy success is associated with it being integrated and embedded across departments within an organisation (for example transport, recreation, open space, strategic planning, assets management, etc.); and when a range of urban greenery’s multiple contributions are actively and intentionally utilised.