Climate Change Fuels Global Spread of Deadly Fungus
As the world grapples with the health impacts of climate change, scientists are raising alarms over a fast-spreading but often overlooked threat: a deadly airborne fungus called Aspergillus. While not a virus or bacteria, this microscopic mould is emerging as a silent killer, posing grave risks to vulnerable populations across the globe.
Experts now warn that climate change is accelerating its reach, making the fungus harder to detect, diagnose, and control. Aspergillus is a genus of fungi commonly found in soil, decaying vegetation, compost, and even household dust. Under normal circumstances, its spores are inhaled by humans daily without effect. But for individuals with compromised immune systems—such as cancer patients, organ transplant recipients, and those with asthma, HIV, or chronic lung disease—the consequences can be life-threatening.
Once inside the human body, Aspergillus spores can trigger a condition known as aspergillosis, a potentially fatal illness that primarily affects the lungs but can also damage other organs. Symptoms are often non-specific—fever, fatigue, coughing—which makes diagnosis difficult and delays treatment. Mortality rates for invasive aspergillosis range from 20% to 40%, according to medical studies. What is particularly alarming, scientists say, is the way Aspergillus is responding to global warming.
Projections suggest that A. fumigatus, commonly found in temperate areas, could increase its spread by nearly 78%, potentially putting nine million more people at risk in Europe alone. Meanwhile, A. flavus, which thrives in warmer climates, is expected to expand its reach by 16%. Ironically, some regions in Brazil and parts of Africa may become too hot for certain Aspergillus strains to survive, creating uneven global impacts.
Urban centres are particularly vulnerable. In the United States, California reports some of the highest exposure levels due to its mix of humidity, pollution, and intensive agriculture. Cities like New York and Los Angeles, with their ageing infrastructure and dense populations, may also face elevated risks. Experts stress that the spread of fungal pathogens remains grossly under-researched compared to bacteria and viruses.
A lead researcher, noted that fungi are now adapting to environmental shifts in ways previously unseen, urging for urgent public health preparedness. As climate change continues to reshape ecosystems, public health systems will need to respond swiftly. Strengthening early detection, improving diagnostics, and reducing fossil fuel emissions could prove critical in containing this emerging threat.
