Climate change is upon us and Australia’s cities are highly vulnerable to its effects. Heat waves are already a leading cause of deaths in Australia and the hard surfaces in cities exacerbate the issue, creating environments that are 4-10 degrees hotter than surrounding areas during the day, with hotter nights too when the heat absorbed during the day is released. This is called the urban heat island effect. How can we mitigate this issue?

A recent Melbourne Conversation explored the problem, discussed what City of Melbourne are doing to better understand the issues and what simple changes we can make in urban planning to cool our cities down.

City of Melbourne have been collecting data from different environments around the municipality for a number of years to compare the effects of these environments in a heat wave. Unsurprisingly, shaded areas are the most comfortable but it is incredible how effective tree canopies are: on a day over 35 degrees, temperatures in the shade of a tree are up to 5 degrees cooler than the surrounding area. The panel stressed the importance of mandating canopy trees in planning policy and one comment from the expert panel was that if a development does not contribute some meaningful tree canopy cover, the design simply isn’t good enough.

Is there anything we can do to reduce the impact of buildings themselves on rising temperatures? The answer is that it can be as straightforward as avoiding dark roofs, a strategy New South Wales has sought to implement into their planning policy.

We were pleased to see that the conversation looked to finding solutions to the urban island effect issue that are low cost or cost neutral and that are also easy for developers to implement. It was also great to see how the panel members value the critical role of urban planning to make a direct impact on climate change.

We note that the panel did not discuss what housing densities our cities need to create the most climate friendly results but that is a discussion for another day.

This discussion was recorded and you can view it here: https://www.youtube.com/watch?v=yAT5oKJuI_w