Melbourne's ‘heat island’ effect

As we swelter through another hot summer there has been a spike in heat-related deaths. This places Melbourne at number one with regards to heat-related deaths. It is not surprising given that current cities have more built up spaces than green spaces, especially the city-centre areas.


Melbourne City Council has done some interesting analysis using thermal images to compare the temperatures coming from different surfaces including: green spaces, road surfaces, buildings and others. One would expect the temperature difference to be just of few degrees Celsius. But it was shocking to see the difference between surface temperature under a tree and nearby surfaces to be as high as 42.4 degree Celsius. This is primarily due to diminution in trees and/or green spaces and increase in grey infrastructure that uses non-heat absorbing materials like asphalt and concrete. Other major contributor is the energy consumption done when the building is in use.

Source: The Age

The study demonstrates that the Melbourne city-centre gets hotter than the suburban areas by 4-5 degree Celsius. One of the reasons stated for this was due to the built form like high-rise buildings as compared to low-rise residential areas. This may also draw Melbournians towards green suburban lifestlye than the concrete city hence leading to more urban sprawl.


The Council proposes to increase the city’s canopy by 18% by 2040 to bring the inner city temperatures down. But simultaneously there is also going to be an increase in infrastructure development. There will be more buildings, roads, cars and people in the city than ever before. Is it beyond just increasing green canopies; it is about the proportion of green infrastructure as compared to the grey infrastructure?


Can it start with simple solutions like roof gardens or vertical landscaping on buildings, train station and small structure like tram stops? Girona in Spain has initiated green roofs on city’s public buses. Is it about taking small-scale creative initiatives like Spain to have vehicles-turned-mobile gardens?