Heatwaves and climate change are Australia’s deadliest ‘unnatural’ disaster
With the mercury soaring in much of the country, extreme heat and heatwaves are fast becoming Australia’s most urgent climate-driven health emergency
Published 16 December 2024
Heatwaves and climate change are Australia’s deadliest ‘unnatural’ disaster
This morning, as I headed into work at a clinic in Melbourne, I noticed a few people sleeping rough on the pavement near the entrance.
The sun wasn’t yet blazing, but even in the early hours, the heat was palpable, radiating off the concrete and a weather forecast for over 40 degrees Celsius.
My mind raced with worry about how they would cope when the temperature peaked later in the day.
For those without shelter, access to air conditioning or even a simple glass of cold water, a day of extreme heat in Melbourne can be unbearable.
And if the heat prolongs over a few days with no cool reprieve overnight then heatwaves can be lethal.
What exactly is a heatwave?
A heatwave isn’t just a hot day.
Defined as a period where maximum and minimum temperatures are unusually high for three consecutive days relative to the local climate, heatwaves are Australia’s deadliest natural disaster – surpassing bushfires, floods and storms.
But because it can take time to report heat-related illness and death, the full human toll doesn't make the news until months after an event.
With Australia warming by around 1.51°C since 1910 and eight of the nine hottest years on record occurring since 2013, we are entering an era of heat.
Globally, 2023 was the hottest year ever recorded – and 2024 is already on track to surpass it.
Climate pollution from oil, coal and gas is heating the planet which is stacking the odds for even longer, hotter and more frequent heatwaves.
The silent and lethal health risks
Heatwaves are a silent health crisis.
They impact everyone but disproportionately endanger vulnerable groups like the elderly, children, outdoor workers, and those with pre-existing conditions.
Prolonged exposure to extreme heat can lead to dehydration, heat exhaustion and heatstroke – all conditions that can turn fatal without swift intervention.
Chronic illnesses, like heart disease and respiratory conditions, worsen dramatically during heat events, and this can lead to increased hospital admissions.
There’s also a quieter, less visible impact: mental health.
Extreme heat disrupts sleep, increases anxiety and, in some cases, contribues to self-harm and psychological effects which are often under-recognised but can profoundly affect individuals and communities alike.
Urban heat islands are a ticking time bomb
Big cities like Melbourne face an added challenge – the ‘urban heat island effect’.
Concrete, asphalt, and steel can trap and radiate heat, making urban areas significantly hotter than their rural counterparts, especially treeless areas with no shade.
While planting trees, increasing green spaces and using reflective materials in urban design can help cool our cities , right now, we’re not moving fast enough to mitigate this risk.
Strain on our healthcare systems
For those of us working in healthcare, heatwaves bring a surge in emergency presentations and ambulance callouts.
It’s not uncommon to see elderly patients arrive at the clinic suffering from dehydration or heatstroke, or to hear heartbreaking stories of people who couldn’t afford to run their air conditioning.
The strain on hospitals and health systems during these events underscores the need for preparedness and resources to handle what are increasingly becoming ‘climate-driven health emergencies’.
Take practical steps for staying safe
While systemic change is essential, we can take practical steps during heatwaves:
Stay hydrated: Drink water regularly, even if you’re not thirsty.
Stay cool: Use air conditioning and keep blinds closed during peak heat.
Check on vulnerable people: Ensure neighbours, elderly relatives, and those with chronic conditions are coping.
Avoid physical exertion: Limit any outdoor activities during the hottest part of the day.
However, personal action alone isn’t enough. These small measures must be supported by bold policies and community-wide action.
Climate change is loading the dice
While it’s impossible to say that climate change caused a specific heatwave, we know it’s making them more frequent, more intense, and longer lasting.
For every 1°C rise in global temperature, the odds of severe heat events increase dramatically.
Australia, as a dry hot continent, is on the frontlines of this climate crisis, and the risks are growing. So, preparing for more frequent, intense and longer lasting heatwaves requires a more coordinated national response.
This includes updating building codes to ensure homes are heat-resilient, more investing in green infrastructure and expanding heatwave early-warning systems.
Public education campaigns must highlight the health risks of extreme heat and empower people with practical solutions.
At the heart of this issue lies climate justice.
Politics & Society
Australia isn’t immune to disaster disinformation
Indigenous communities, rural populations and low-income households often bear the brunt of extreme heat. Many can’t afford air conditioning or live in poorly insulated housing, leaving them dangerously exposed.
Addressing these inequities is not just a matter of health – it’s a matter of fairness.
Heatwaves are a wake-up call
Ultimately, the solution lies in tackling the root cause of the problem: climate pollution.
Australia is already generating about 40 per cent of its electricity in the main grid from renewables, but we need to do more, and faster. We must focus on rapidly scaling up renewable energy, backed by storage, and seriously committing to cutting climate pollution from coal, oil and gas.
Heatwaves are not just a warning sign – they’re a wake-up call
As I think back to the people I saw sleeping on the pavement this morning, I’m reminded of the human cost of inaction.
It’s time for Australia to lead by example, preparing for the climate challenges ahead while working to prevent the worst impacts of global warming – we can’t afford to wait.