Greater Sydney's climate means that communities are exposed to both heatwaves (more than three consecutive days of abnormally high temperatures) and extreme heat (days above 35 degrees Celsius). The Western Parkland City is more exposed to extreme heat than the other cities (refer to Figure 57). Climate change is likely to increase exposure to extreme heat and heatwaves. The urban heat island effect can also increase localised exposure to heat.
Heatwaves and extreme heat have a significant impact on human health. Heatwaves are estimated to cause more deaths in Australia than any other natural hazard. In addition, heatwaves and extreme heat can lead to more illness, which places pressure on communities, emergency services and the health system. Older people, young children and people with existing illnesses are generally more vulnerable, as are people who work outdoors. Bushfires triggered by heatwaves and extreme heat also have impacts on human health and safety.
Heatwaves and extreme heat also place great pressure on infrastructure, particularly on the electricity network during times of peak demand. Heat-related power shortages have the potential to place further pressure on vulnerable people and communities.
Increased demand for electricity for air-conditioning and other forms of cooling contributes to increased greenhouse gas emissions, further exacerbating extreme heat linked to climate change.
Extreme heat makes it less attractive for people to walk and cycle and spend time outdoors. The planning of great places and liveable neighbourhoods needs to consider how the urban heat island effect can be mitigated, particularly in areas with a higher proportion of vulnerable people.
Objective 26 describes the vision for a cool and green city in the South Creek corridor and Objective 30 highlights how the urban tree canopy can help mitigate the urban heat island effect, keep Greater Sydney cool and improve the amenity of local communities.
Building materials can support the mitigation of the urban heat island effect. Cooler building materials, including lighter-coloured roofs, lighter-coloured paving and more permeable paving, can be highly effective. In some circumstances where it is difficult to expand the urban tree canopy, innovative design measures can be used to increase shade and reduce heat.
The NSW State Emergency Management Plan includes the State Heatwave Sub Plan, which details the control and coordination arrangements across State and local governments for the preparation for, response to, and immediate recovery from a heatwave.
Mitigate the urban heat island effect and reduce vulnerability to extreme heat.