Making cities cooler and safer

Urban overheating is a growing problem, so UNSW researchers have created a national index to measure and then mitigate heat vulnerability in Australia’s towns and cities.

With 2023 the hottest year ever recorded on Earth, Australia’s summers are undoubtedly getting hotter and more dangerous. Urban heat is linked not just to increased deaths and emergency admissions, but also increased energy and water consumption, as people try to cool down.

Some communities are more vulnerable to the effects of heat, often due to living in towns and cities that are more impacted by the Urban Heat Island effect – where high-density urban areas have a higher ambient temperature compared to surrounding suburban or rural areas – and also because they have less access to cooling resources such as air-conditioning (with the cost of running air-conditioners an additional barrier).

Understanding heat vulnerability and how to reduce it has become increasingly important due to the impacts of climate change. It is now a policy and planning priority for all levels of government in Australia.

And that’s where UNSW researcher Associate Professor Lan Ding and her colleagues at UNSW’s High Performance Architecture team are making an impact.

Ding is leading a project to create a National Heat Vulnerability Observatory Index (NaHVO) to provide a standardised approach to data collection and measurement of heat vulnerability, including the impact of the built environment.

The data is then used to model the impact of different heat mitigation strategies and advise local authorities about which would be most effective in their locations.

“Addressing the impacts of urban heat vulnerability is critical for Australia to plan for resilient, sustainable communities to combat climate change”, Ding says.

“Concerningly, many of the places in Australia that are most vulnerable to extreme heat have been designed without enough of the features that mitigate heat, such as urban surface treatments, green spaces and trees with water irrigation, and water-cooling systems.

“This exacerbates the urban heat island (UHI) effect and thereby intensifies the health, economic and environmental impacts of extreme heat for these populations.”

The NaHVO is a partnership between the NSW Department of Climate Change, Energy, the Environment and Water and UNSW's High Performance Architecture team, and has an advisory committee with representatives from government, industry and academia.