Heat and our health

Most Australians know that heatwaves are an enduring feature of our climate. But did you know that extreme heat leads to more deaths and hospital admissions annually than any other hazard in Australia?

Heatwaves are also the cause of some significant social, mental health, and economic impacts. It's estimated that in labour productivity alone Australia loses $8.7 billion per year from heatwaves. The expected losses to crops from heatwaves are projected to reach over $100 million in coming years.  

While the drivers of heat impacts on our health are complex, we know that individual factors (such as age and health status, our built and social environments, and access to cooling and health services) play a considerable role. Many Australians may be dealing with more than one of these drivers simultaneously. Take, for instance, an elderly person with ailing health, living alone in a building without access to cooling.

As Australia's climate continues to warm, heatwaves are expected to become more frequent, more intense, and longer lasting. In fact, every decade since 1950 has been warmer than the previous one.

Understanding the risk to communities has never been more important and is critical to creating effective policy, planning, and interventions to minimise risk.

See the ACS website for more information -  Heatwaves | Australian Climate Service (acs.gov.au) 

A team of scientists from the Australian Climate Service (ACS) took a deep dive into the latest data to build a nationally consistent approach to identifying regions at high-risk of adverse effects of heatwaves, now and into the future.

The study aims to provide policy experts with opportunities for targeted adaptation. 

The work provides insights into how much more, or less likely people are to visit emergency departments, see a general practitioner or even die under different extreme heat scenarios. This snapshot of current conditions was combined with modelling of future climates and health outcomes. 

Along with this analysis, a pilot Heat-Health Risk Index was developed to provide a more detailed spatial view of people and places most at risk.  

The Heat-Health Risk Index is an approach and evidence base that helps us understand the ways that health-risk varies socially and spatially across Australia.

It uses the latest data and thinking on the social, economic, built, and natural environments to create indicators of how communities are at risk to adverse heat-health outcomes.

The methodology behind the Index has been adapted from several international best practice frameworks and updated to take into consideration the latest thinking on climate risk (e.g., IPCC AR6).

The Index is provided as a set of maps that allow for the exploration of different risk components, including the ability to compare places and communities at a fine level of detail.

Overall Heat-Health Risk is the broadest level and provides a single number describing the ranking of places from low to high risk. The overall measure can also be disaggregated to better understand risk components such as exposure, social vulnerability and adaptive capacity.

The results paint a stark picture of just how heatwave impacts vary between populations and locations across the country.

Using some areas of Greater Sydney to give a snapshot, you can see the degree of differences in the maps below.

How to interpret these maps

The colour indicates the degree of heat-health risk in our local communities based on the distribution of population. This is based on the Australian Statistical Geography Standard (ASGS)  Statistical Area Level 2  (SA2) boundaries which approximate neighbourhoods in built up areas and have been mapped onto the  Australian Population Grid . 

To see the Health-Heat Risk Index for your local area, use the zoom function on the bottom right and click on a region.

Climate modelling undertaken as part of the study showed the potential heat health impacts for Australia if the warming level reached 1.5, 2.0 and 3.0°C.

Global Warming Levels of 3°C could increase average heatwave peak temperatures by over 4 degrees, resulting in more hospital admissions and deaths from extreme heat.

Use the swipe tool below to compare the average heatwave peak temperature across Australia for the 1.5°C and 3°C Global Warming Level scenarios.

Heatwave related health impacts can be minimised with a range of policies and programs across different levels of government, industries, and community service organisations that can reduce this risk.

Most state and local governments across the country already have some heatwave warning systems and cool space infrastructure in place. However, we lack a nationally consistent approach.

As climate change impacts increase, we need to adapt and create effective policy and interventions to improve heat-health outcomes.

Understanding current and likely heat health risk will help us identify more targeted interventions to better protect people and places most at risk. Helping communities understand their risk can support them to identify adaptation responses that make sense in their local area.

This Heat and Health pilot study was undertaken by the Australian Climate Service for the National Climate Risk Assessment (the Risk Assessment). The study helped to test the methodology behind the Risk Assessment during the first pass. The Heat-Health Index has been made available to the National Emergency Management Agency to assist with decision-making. To find out more about the Australian Climate Service's role in the Risk Assessment, visit:  National Climate Risk Assessment | Australian Climate Service (acs.gov.au)