Climate Change Impacts on Environmental Fungi: Human Health and Fungal Disease.

Climate changes including rising temperatures and increasing severe weather events (e.g., hurricanes, flooding, and wildfires) are impacting Earth's ecosystems and increasing microbial threats to human health. Microbes in the environment, including bacteria and fungi, are adapting to new habitats and hosts in ways that may make them more disease-causing. Environmental fungi are particularly climate-sensitive, with optimal growth at cooler temperatures (25-30 °C) and with reproductive spore dispersal dependent on atmospheric conditions. While environmental fungi play a crucial role supporting plant growth and recycling nutrients in soils, some cause mild to severe infections in humans. Climate changes are expanding the geographic range of some disease-causing fungi, leading to increased fungal infections, particularly in the aftermath of natural disasters. Additionally, fungal adaptations to environmental stressors may make fungi more likely to cause disease, such as increased heat tolerance (survival at body temperature of 37 °C), or more difficult to treat, due to evolving drug resistance to environmental fungicides. Here, we explore how climate change and natural disasters impact fungal distribution, adaptation, and exposure to humans, highlighting fungal threats to human health. We propose strategies to mitigate these emerging challenges, emphasizing the collaborative and interdisciplinary efforts needed to protect human health in a changing climate.