The setup for The Last of Us video game and TV series involves a fungus that evolves due to climate change to infect swathes of the human population, turning people into killer zombies – and at least part of that story is eerily plausible.
Scientists are raising concerns about the increasing spread of Aspergillus fungi, helped along by climate change and warmer temperatures. These types of fungus don’t turn people into zombies, but they can cause severe health issues and even fatalities in people, plants, and animals.
In a new study, which has yet to be peer-reviewed, researchers in the UK show how three species – Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger – are likely to spread further north between now and 2100, based on their existing habitats and climate models predicting future warming.
“Changes in environmental factors, such as humidity and extreme weather events, will change habitats and drive fungal adaptation and spread,” says environmental mycologist Norman van Rhijn, from the University of Manchester.
“Fungi are relatively under-researched compared to viruses and parasites, but these maps show that fungal pathogens will likely impact most areas of the world in the future.”
Under the severe climate scenario, the spread of A. fumigatus in Europe could increase by 77.5 percent in 15 years, putting 9 million more people at risk of infection. For A. flavus, which favors hotter areas, the spread might be as much as 16 percent in Europe, putting an extra 1 million people at risk. For A. niger, the data showed a more stable picture across the coming decades.
This is a nuanced issue though: as the fungi spread to areas that were previously too cold, they’re also likely to be driven out of regions that get too hot. Overall, the number of people exposed to these types of fungus will decline by 2100, the study shows.
However, it’s the spread to new areas – and potentially vulnerable people, especially those with weakened immune systems – that the researchers are worried about. There’s the possibility we’ll also see more infections in healthy individuals as these species adapt.
It’s not just human infections we need to worry about, the team says. Fungal outbreaks can decimate crops, adding to the growing challenges of feeding the world’s population under climate change.
“The potential for increased human exposure in Asia and Europe, combined with contraction in parts of Africa and South America, could alter public health burdens and crop biosecurity landscapes over time,” write the researchers in their study.
As the researchers note, the fungus Candida auris has also been of concern to scientists. Capable of causing significant health problems, it too has been spreading further as the world warms up, and other species are likely to follow.
Another important factor is the flip side of these fungi: the benefits they bring to ecosystems, including carbon and nutrient recycling. This all needs considering when weighing up the shifts being caused by climate change.
“Raising awareness and developing effective interventions for fungal pathogens will be essential to mitigate the consequences of this,” says van Rhijn.
The study hasn’t yet been published in a peer-reviewed journal, but is available at the preprint platform Research Square.
