The Heat is on: Addressing Australia’s Silent Security Crisis

Chelsea Golding | Climate and Environment Fellow

Image sourced from Roland Schedel via Wikimedia Commons.

If you have opened the news at any point over the past year, it has been nearly impossible to avoid repeated headlines announcing case after case of record-breaking heat, with countries from the United Kingdom to China already confirming 2025 as their hottest year on record. These soaring temperatures have seen roads melt and crops wither, while in many countries, hospitals have struggled to cope with record numbers of heat related cases.

Australia has been at the frontlines of this issue, with a drastic increase in both the frequency and intensity of heatwaves over the last decade. Between 2006 and 2017, extreme heat was linked to more than 36,000 deaths across the country. This makes extreme heatwaves our most dangerous natural hazard, responsible for more deaths than floods, fires, or cyclones combined, earning them the reputation of Australia’s “silent killer”.  However, prolonged and intensifying heatwaves stand out from other climate hazards in more than just mortality numbers.

The independent impacts of extreme heat are well known. The cumulative effects of these impacts however are too often overlooked. Prolonged and intensifying heatwaves are not only a public health or infrastructure challenge, but also a fast-emerging threat to national human security straining social cohesion, weakening food and economic security, and creating conditions for civil unrest that Australia is not equipped to manage.

What Makes Heat Unique?

But why call extreme heat a security challenge, and not simply a public health crisis or threat to infrastructure?  Heatwaves are not just threatening health and wellbeing on an individual level – they are creating the conditions for broader political and economic instability. By threatening the compounding factors that underpin human security, extreme heat and its social consequences far exceed what can be addressed through traditional responses to health crises or even emergency disasters.

Climate change has been widely recognised as a “threat multiplier”: a force that may not create conflict on its own but one that amplifies existing vulnerabilities such as poverty or fragmented governance, making instability far more likely. Extreme heat, however, stands as an exception, as there is a strong and direct connection [BN1] between exposure to extreme heat and increased violent behaviour. A landmark study found that a 3˚C rise in temperature, can increase violence between individuals by 4 per cent and conflict between groups by a staggering 14 per cent. This is particularly alarming given a 3˚C rise is predicted by 2100 under the IPCC high-emissions projections.

These findings have also been seen repeatedly in real world contexts, with documented increases in riots and violent crime occurring alongside severe heat events across a range of countries including Egypt, Indonesia and Mexico. It is this direct correlation between violent behaviour and heatwaves that sets excessive heat apart from other climate extremes. Unlike other climate shocks, which lay the kindling for instability, excessive heatwaves also light the match.

Australia: The Sunburnt Country

Despite its relative economic prosperity and political stability, Australia is far from immune to the destabilising impacts of extreme heat. Due to its hot dry climate, ageing population and broad population distribution, Australia is considered to be one of the most heat exposed developed nations. The Australia Institute notes that while the United States and areas within Southern Europe may be exposed to similar soaring temperatures, the geographic isolation and distribution of Australia’s rural communities create a barrier to adaptation and a level of vulnerability not seen in other developed nations. Approximately 38 per cent of Australians live in areas classified as having “very high” exposure to the hazards associated with extreme heat. The most vulnerable are often those facing the brunt of existing inequalities, as these communities are more likely to lack the infrastructure and social support systems needed to manage extreme temperatures.

This is seen clearly amongst Australia’s agricultural communities. Over the past two decades, climate change and extreme heat have reduced farming profits by an estimated 23 per cent, with the most severe impacts felt in inland regions. These losses not only further entrench inequalities in rural communities but as temperatures rise, could threaten broader stability in the country. For example, lower agricultural output can trigger both supply shortage and price surges, resulting in increased insecurity. Over time, this may contribute to escalating tension and even conflict in communities already under pressure. The impacts of extreme heat interact beyond isolated sectoral risks, and their compounding effects undermine core pillars of human security.

Where Australia Falls Behind on Heat Security

Despite the risk of heat to national security, Australia’s policy response remains fragmented at best. Within policy frameworks, the effects of extreme heat are consistently categorised with other climate hazards as “threat amplifiers” and their unique potential to drive instability is overlooked. In contrast, many other developed nations have taken a direct response to this rising threat, explicitly integrating heatwaves into interdisciplinary intelligence and defence planning. The United States Department of Defence, for instance, goes beyond treating extreme heatwaves as another broad climate risk, instead developing targeted procedures for the specific security challenges they present.

Unlike other climate hazards, extreme heat presents a unique security challenges as it both creates the conditions for insecurity and the spark that ignites it. Exacerbated by Australia’s vast geography and widely dispersed population, these compounding pressures heighten vulnerability and restrict the capacity for communities to adapt. Australia must therefore move beyond viewing heat as an environmental hazard and adopt a strategic, coordinated response that integrates extreme heat into national security frameworks.

Chelsea Golding is the Climate and Environment Fellow for Young Australians in International Affairs. Chelsea is an undergraduate at the University of Queensland, pursuing a dual Bachelor of Science and Bachelor of Arts.

She has conducted policy research on offshore wind development in Australia, contributed to marine spatial planning studies, and drafted environmental legislation. Her international experience spans Malta and the Philippines, ranging from marine animal studies and coastal habitat monitoring to regulatory reviews and community-based marine policy evaluations.

As UQU’s Environmental Officer, Chelsea co-founded the Environmental Collective column and led campus sustainability initiatives. She has worked across government and research sectors and is especially interested in environmental justice and climate resilience in the Indo-Pacific.

Our 2025 Climate and Environment Fellow is sponsored by the Sydney Environmental Institute. For more information, visit their website here.

The views and opinions expressed in this article are those of the author, and do not necessarily reflect the views and opinions of Young Australians in International Affairs. AI tools were used by this author for the structuring of research, but all content is original, and no plagiarism has been used in the preparation of this article.