Rising levels of extreme heat in Australia are contributing to increases in mental health problems, heart attacks, financial distress and ecosystem collapse, while also bringing down birth rates, experts have warned.

In addition, psychological distress caused by climate change fears, particularly among young people, is adding to the burden on the country’s health system.

The average temperature in Australia has risen by 1.4°C since national records began in 1910, according to studies, with the temperature in Sydney varying by as much as 10 degrees between the coast and the west during heatwaves.

“[People] often don’t talk about the emotional impact of awareness of climate change and the impact this has on the way in which they approach [climate distress],” said Dr Carol Ride, executive director of Psychology for a Safe Climate.

“What we do find is that people talk about the feelings that are very pervasive around climate change, which is sadness, deep grief, fear, anger, shame, and a struggle with hope.”

Dr Ride claimed, based on her experience as a psychologist, ‘shame’ is more prevalent in older generations, while younger people were more reluctant to have children.

“[They’re aware] that the life they’ve led has actually had a serious impact on the state of the global climate,” she added.

It’s very complex, especially for young people because [they] have fear about what the future is going to be like.

“They were caught in the whole bubble of economic growth [and] making the most of opportunities, [without] realising that the wealth that was being accrued and that the travel and the consumption was actually contributing.

“Even the people who are younger [feel] very anxious about the lifestyle they’re living. One of the very troubling things is [that] younger people [are] deciding not to have children.

“They feel shame if they bring more people into the world to contribute to the consumption. So it’s very complex, especially for young people because [they] have fear about what the future is going to be like.”

Dr Caroline Gao, an environmental epidemiologist and senior biostatistician at youth mental health group Orygen, agreed young people were more likely to be affected.

“We believe urgent action is required to better support young people,” she said. “We want to reduce the impact of climate change on psychological distress, foster hope and avoid despair, while still motivating positive climate actions.

“Young people are particularly vulnerable to mental ill-health; the onset of almost half of all mental health disorders occurs before the age of 18.

“With the extreme climate occurrences that have occurred in Australia over the last three years, it is likely that climate concerns are contributing to the exacerbation of mental ill-health for some of our young people.”

Think twice before you turn on air con

It might seem like a no-brainer to turn on your air conditioning when it’s hot, but Australian National University researcher Dr Simon Quilty suggests otherwise, warning of a higher predisposition of heart attacks in hotter weather as people adjusted from air conditioned environments to non-air conditioned.

“If you have underlying heart disease, and you’re walking across a very hot carpark, your heart actually has to pump harder to allow your physiology to respond to that heat,” he said. “[That] increased heart rate may increase the risk that you have a heart attack.

“But it goes throughout any kind of vulnerability. So for instance, if someone has dementia, then they won’t be aware of their body’s response to the heat, and [are] more likely to get heat stress. [Children] have smaller surface areas, [and] have less capacity to escape from that heat. It also goes right into the way people live.”

Dr Quilty drew from his work with the Wilya Janta Housing Collaboration in Tennant Creek, where the average temperature in November is 30°C.


“In the Northern Territory, if you don’t have access to a fridge, then your medications can spoil,” he said.

“If you live in a poorly designed house, then the house gets very hot without air conditioning. And so in really hot weather, your electricity bills go up. And if you have limited access to finances, then the electricity bills will eat into your food bills.”

People with underlying health issues, taking multiple medications are the most vulnerable, said Doctors for the Environment’s mental health special interest group co-chair Dr Cybele Dey.

“These periods can be really high risk [for them], where if they’re not taking the right care and not getting access to cool shelter, [they’re] much more likely to get very sick,” she said.

Dr Milton Speer, visiting fellow in the School of Mathematical and Physical Sciences at University of Technology Sydney, said the climate crisis also had an affect on a person’s socioeconomic status.

“[Western Sydney] will increasingly experience more heat extremes than coastal Sydney,” he said. “Western Sydney has a higher unemployment rate and the highest proportion of low income families in the Sydney region.

“Low income families can’t move anywhere else, and these circumstances take a toll on [their] mental health.

“The difference between coastal Sydney and Western Sydney is increasing in terms of temperature. Coastal Sydney has more influence from the ocean, whereas Western Sydney heats up without that influence.

“So, even though one of the main features of global warming is increasing sea surface temperatures relative to Western Sydney, the coast is not heating up as fast.”

A study by Dr Speer found differences of up to 10 degrees celsius on certain days, between coastal and western Sydney. On average Western Sydney is 0.8 degrees hotter than the coast.

“We know that as the temperatures get to the hot-to-uncomfortable stage, that starts to stress not just the human body, but all of the systems and institutions and services that keep people healthy,” added Dr Quilty.

Ecosystem collapse

Western Sydney will see two thirds of population growth in the next decade, according to the NSW government.

Extreme heat put the ecosystem at risk of collapse, Dr Speer said

“And with this population growth comes infrastructure development, which is a challenge to the natural environment when heat extremes are increasing,” he added.

“One of the main features of ecosystem collapse in recent years in the Australian media has been to do with the Murray Darling Basin and the two river systems: the Murray and the Darling [that] sit in southeast Australia.

“In the long extended drought period from 2017 to 2019, many of the streams dried up and consequently the Darling River became [a] series of potholes with water in it. [They] experience algal blooms from the excessively warm temperatures, which meant the water was deoxygenated and [caused] thousands or even millions of fish to die in 2019.”

The heavy rain of 2021 and 2022 also added to the risk.

“Over the summer … a lot of the water that ran out onto the floodplains [returned] to the river [as] black water,” said Dr Speer.

“[Black water] is deoxygenated water from all the fertilisers and other chemicals [used] by irrigators and farmers, and [that] produces the deoxygenated water and [more] fish death.”

Swift action by government needed

Dr Dey urged the government to be more proactive.

“From a Doctors For The Environment Australia point of view, there are lots of opportunities for government and organisations to be taking action that [help] protect people’s health now and into the future,” she said.

“First Nations Australians, Aboriginal and Torres Strait Islander Australians have been caring for country for so long. That wisdom and knowledge about how to care for country without causing environmental harm [is] already here, and there is an enormous amount of generosity among First Nations people and traditional owners to share that wisdom and to work together for solutions.”

She said more support for the public was needed, adding: “That includes things like [having] good information about how to keep themselves and their loved ones and community safe during heat waves, bushfires, storms, and floods, and [access] to services in a timely way.

“Bushfire smoke [is] actually the most lethal part of bushfires, and it’s often the interaction of smoke and heat that causes the most harm.

“By seeing government action, we would actually see a benefit in people’s mental health around climate distress as soon as it happens.

Young people overwhelmingly want action on climate change, and Australia must act to reduce the harm young people are experiencing.

“People who are already concerned will be seeing more and more increases in climate change, fossil fuel driven hot weather, and bushfires. And that increases people’s distress. Even just being aware that it’s happening without an adequate government response, then the whole population is being impacted by the actual hot weather and by the bushfires.”

Marion Bennett, Mission Australia’s executive of practice, evidence and impact, said professionals need to be upskilled and young people needed to be involved in the process.

“Young people overwhelmingly want action on climate change, and Australia must act to reduce the harm young people are experiencing,” she added.

“We urge governments to update their youth and mental health strategies so there is increased access for all young people in Australia to mental health services, to raise awareness and to upskill professionals in the realm of climate-related distress.

“It’s also important that governments partner with young people to co-design solutions that will address their climate-related mental health concerns.”

Resources on the NSW Health Climate Risk & Net Zero page can be found here.

Main image by Erin Hee.