What ‘The Last of Us’ got us thinking about

The scariest part of The Last of Us was never the zombie fungus… it was the real-life question underneath it.

What happens when the natural world changes faster than we can adapt?

In case you live under a rock (or a mushroom), The Last of Us began as a video game and was adapted into one of the most talked about television series of recent years. With a deeply unsettling premise, the show is centred around a mutated strain of Cordyceps fungus that infects people and hijacks their nervous system, turning them into something closer to a zombie than a human. Civilisation collapses, and the few who survive are trapped in a world overrun by the infected.

Why is the story so disturbing, you might ask? Well, because it is scientifically plausible.

While Cordyceps sounds like something you might only see in science fiction, it’s actually a real type of fungi, and it really does zombify its hosts.

Luckily for us, their main hosts are ants.

The Cordyceps fungus (Ophiocordyceps unilateralis, or O. unilateralis) infiltrates the body of a carpenter ant and takes control of its motor functions. It causes the ant to climb to an optimal height of 10 inches above the ground. At this height the ant sinks its jaws into a leaf vein, and the fungus erupts through the ant’s head. This allows the fungus to expel its spores into the environment. The high vantage point means the spores rain down and can infect other ants from the colony.

In the show, rising global temperatures due to climate change cause the fungus to adapt to higher temperatures, allowing it to withstand warmer environments, such as the human body.

However, scientists are fairly sure this specific scenario won’t happen in real life, since O. unilateralis has spent millions of years specialising to infect a single species of ant. The leap to humans (within any relevant timescale) is extremely unlikely. Which is lucky for us in Australia because these zombie ants have been found in the Northern Territory!

But the show’s underlying logic isn’t fiction. Rising temperatures are already causing species to evolve in ways we can’t fully predict.

Climate change is not just an environmental story

When we think about climate change, we often think about more intense storms, rising sea levels and longer droughts. However, that’s not the whole story. Climate change is also a human health issue.

Underneath those headline weather events, the entire biological world is being reorganised. Temperature governs almost every living thing. It determines where a mosquito can survive the winter, how fast a virus can replicate inside a host and whether a fungal spore can persist long enough to infect a passing human.

As global temperatures change, diseases are adapting and shifting locations. In many cases, they have more hosts or thrive in new regions. The Last of Us brilliantly made the process of climate adaptation personal.

The real horror lies not in the infected, but the realisation that the conditions enabling this fictional catastrophe – higher temperatures – are already underway.

From zombies to mosquitoes: the dangers of a warming planet   

One of the clearest examples of climate driven disease expansion involves mosquitoes. While they probably won’t be getting a spin-off of The Last of Us (mosquito apocalypse anyone?), they do share a key trait with zombies – their damage starts with a bite.

While mosquitoes won’t turn you into a zombie like their fictional counterparts, their bite is far from harmless. In fact, mosquitoes are among the deadliest animals on the planet, transmitting diseases that affect millions of people each year. What makes them especially concerning in a warming world is their sensitivity to temperature. Mosquitoes thrive in warm conditions and become inactive in the cold. Historically, this means cooler climates have acted as a strong and natural barrier to the diseases mosquitoes carry.  

As average temperatures rise and winters warm, the once-clear boundary between mosquito survival and death is changing. Mosquitoes that were once confined to tropical and subtropical regions are now establishing populations further north and further south. As their range increases, they bring with them diseases such as dengue fever, Zika virus, and malaria into populations of people with little prior exposure.

And it’s not just the geography that changes, but also the timing. Higher temperatures extend the seasons in which mosquitoes are active, increasing the duration of transmission periods. For viruses, such as dengue fever and Zika, that use the mosquito as a host, higher temperatures can speed up viral replication inside the mosquito, meaning the insects become infectious more quickly.

Malaria is caused by a parasite that uses mosquitoes as a host, it alone kills over 600,000 people annually. As mosquitoes push into new regions with longer transmission periods, those numbers are only set to climb.

In rural and remote areas, whether in sub-Saharan Africa, Southeast Asia or Australia’s Northern Territory, a disease outbreak can mean a 2-hour trip to the nearest clinic or an overstretched healthcare facility. Although malaria does not typically occur in Australia, outbreaks have occurred in Queensland, including the Torres Strait. The mosquito species capable of spreading malaria is already present across the northern part of Western Australia, the Northern Territory and Queensland. If the malaria parasite is re-introduced into the Northern Territory the disease could re-establish in Australia’s population.

Treating non-fictional fungi: we’re running out of options  

The creators of The Last of Us did their homework. Fungal infections are extraordinarily hard to treat compared with bacteria, they are poorly understood and are quietly killing more people than many well-known diseases.

The reason fungi are so difficult to treat comes down to their basic biology. Fungi are eukaryotes, meaning their cells are structurally similar to ours. Anything toxic enough to kill a fungus tends to cause significant damage to their human host, too. As a result, the antifungal drug options are remarkably narrow. There are only four main classes of antifungals, which becomes dangerous when resistance to those develops.

The scale of the problem is larger than most people appreciate. Of the millions of fungal species on Earth, only a few are known to infect humans. But that small fraction is estimated to infect nearly a billion people annually and is associated with over 1.6 million deaths, which is comparable to tuberculosis.

Climate change is accelerating the problem in several interconnected ways. The rising temperatures and shifting weather patterns are expanding the geographic regions where dangerous fungi can survive. This is pushing species like Coccidioides, which is responsible for Valley fever, as far north as Washington in America.

Then, there is the issue of drug resistance. Agricultural fungicide use is already widespread and is expected to increase further as temperatures rise. This is driving the emergence of antifungal resistant strains in the environment. Triazole fungicides, used extensively on various crops, are chemically related to the triazole antifungal drugs used in hospitals. Fungi exposed to these compounds in the environment are developing resistance that carries directly into the clinic, where critical infections then fail to respond to treatment.

Perhaps the most troubling acceleration is the fungal adaption to heat, which is what The Last of Us depicted. Currently most fungi cannot survive at human body temperature, and this has been our most reliable defence. However, as ambient temperatures rise, that barrier is eroding. Fungi are under selection pressure to tolerate more heat and those that adapt may find the human body a suitable environment. New fungal diseases may emerge as a direct consequence.

The scariest part is that this is already happening. Fusarium oxysporum, once known purely as a banana pathogen, is now recognised as an emerging human pathogen.

The World Health Organisation (WHO) has now formally ranked fungal threats for the first time, a recognition that the danger is no longer theoretical. Among the most alarming is Candida auris, a superbug that researchers believe may have evolved into a human pathogen by adapting to higher ambient temperatures. This makes it a rare and troubling example of climate change directly driving pathogen emergence.

Candida auris sits at the top of the WHO’s critical priority list. It thrives in hospital settings, spreading between patients via shared equipment and through contaminated surfaces, and it is extraordinarily difficult to stop. Most strains are resistant to fluconazole, the world’s most widely used antifungal drug, and many resist multiple medications simultaneously. For patients already weakened by illness or surgery, the consequences can be devastating — serious bloodstream infections, wound infections, and systemic failure in those least able to fight back.

So, while they may not turn you into a zombie, fungi can have real consequences and an impact on human health. It may even kill you.

The experiment no one signed up for

Organisms don’t adapt to climate change by choice; they adapt because individuals with traits that suit the new conditions survive and reproduce at higher rates than those without. Over generations these traits then become more common. Climate change functions as a selection pressure, it changes the conditions that they live and reproduce under, redirecting evolutionary change in ways that are hard to predict.

The concern isn’t a single dramatic transformation. It’s that we are running a large, uncontrolled experiment on the biological world. Pathogens could behave in new ways, in new places and affect people who had no reason to be prepared.

Fiction has a unique ability to make scientific ideas feel real. The Last of Us captures attention by taking a plausible concept and pushing it to its extreme. While this specific scenario may not happen, the story opens the door to real conversations about how pathogens evolve and how environmental change influences evolution.

The picture is serious – but it’s not hopeless. Understanding how climate change is reshaping the biology of disease is precisely where better decisions get made, by researchers, policymakers and by the public.

After the WHO’s fungal priority list, we’ve already seen a surge in research for fungal pathogens. For each critical fungal pathogen new drugs such as ibrexafungerp, rezafungin, fosmanogepix, or olorofim have shown promising clinical results. The research is still ongoing, even this year scientists have unlocked a new weakness in a deadly fungus. It’s a compound called an ‘adjuvant’, which is a kind of helper molecule that doesn’t kill the fungi but makes it easier to treat with existing medicine. It does this by blocking a protein essential for its functioning, meaning some of old antifungal treatments that had built up resistance may be back on the table. This treatment has already shown promising results for the fungi Candida auris.

Recent developments in renewable energy and climate science suggest that meaningful progress is being made in addressing climate change. According to the 2026 European Electricity Review by Ember, wind and solar power generated 30% of the European Union’s electricity in 2025, surpassing fossil fuels for the first time on record. Coal use also fell to a historic low, highlighting a major structural shift toward cleaner energy systems. Australia is experiencing a similar turning point: in September 2025 renewables overtook coal on a monthly basis for the first time, generating 48.8% of electricity compared to coal’s 47.6%. At the same time, scientists are exploring innovative carbon-removal solutions, including the use of fungi to capture and store carbon in soil. It turns out fungi aren’t just practising for the apocalypse, some may actually help prevent one.

What makes the difference is conversation. The more people realise that climate change is not just an environmental story but a human health story, the harder it becomes to treat it as someone else’s problem.

The science of how climate change is reshaping life on this planet is still being written. The best thing we can do is keep communicating it.

If you’d like help communicating your science, get in touch with us at info@scientell.com.au.