The evidence that green infrastructure can be used to improve urban climates is growing. This knowledge is beginning to translate into policy, with many cities and towns establishing policy strategies and targets aimed at increasing green infrastructure in cities, especially tree canopy cover, with the aim of cooling urban areas. However, when it comes to implementation, just how should green infrastructure be rolled out across our cities? Does it matter WHERE green infrastructure goes? Does it matter WHAT green infrastructure is used? What does this mean for urban climate?

While increasing vegetation cover broadly leads to urban cooling at the local-scale, at the miro-scale the influence of green infrastructure can be quite 'specific'. Within a policy and urban design context, this presentation will focus on the strategic implementation of green infrastructure, particularly street trees, that is targeted towards maximising benefits for human thermal comfort in our cities. Further, the influence of the urban landscape and the role of water on tree health and evapotranspiration is also discussed, drawing on research from the CRC for Water Sensitive Cities.

While the overarching aim of increasing green infrastructure has gained traction, the guidance on ‘what green infrastructure should be placed where’ requires further research and communication. Capturing important urban/vegetation dynamics in urban land surface schemes, while making simple user friendly tools available to help value the thermal benefits of green infrastructure and inform decision making, is also a challenging paradox. Trees and water have a vital role to play in creating liveable cities, through science informed policy, for the world's expanding urban populations.