5 things to know about infectious disease and climate change

The Society of Environmental Journalists annual conference convened a panel of experts April 25 in Tempe to discuss the spread of infectious diseases amid climate change.

Here are five takeaways. 

Valley fever cases to increase as Western US gets drier and hotter

The fungus that causes valley fever grows in hot, dry climates. Current models of climate change suggest more parts of the U.S. will have the hot, dry conditions that sustain this fungus. 

Bridget Barker, a professor at Northern Arizona University specializing in fungal diseases, including valley fever, predicted that by the end of this century, the entire western U.S. would be amenable to the growth of the valley fever organism. 

 “Clear up to the Canadian border,” Barker said.

Warmer temperatures could allow fungi to survive at body temperature

Higher average temperatures could act as an evolutionary pressure, allowing fungi to survive at greater temperatures.

Currently, one of the human barriers to fungal infection is a high internal body temperature. 

“As we have higher and higher global temperatures, on average, selection will drive those organisms to be able to tolerate higher and higher temperatures,” Barker said. 

Heat waves are becoming more frequent and intense

Mona Arora, a professor at the University of Arizona who studies the relationship between public health and heat, said heat waves in Arizona are becoming more frequent and intense, with consistent triple-digit days from April to October.

“When we think of a disaster, we’ll probably think of something like a flood or a hurricane or a wildfire. There’s a visual star,” Arora said. “For something like heat, what is that trigger?”

The environment: Arizona’s wildfire forecast is … complicated. Drought, climate change disrupt rhythms

Public health data collection infrastructure is extensive but fragile 

Public health researchers rely on data collected by a network of public and private entities to track the spread or risk of infectious diseases. Much of this data is organized by the Centers for Disease Control and Prevention. 

Arora said risk-mapping tools rely on the CDC Social Vulnerability Index. The index is used to identify the communities most at risk during a public health emergency. “If that goes away, I think there’s a lot of other tools that will see that domino impact.” 

In January and February 2025, several CDC webpages containing publicly available datasets were removed, though most were later put back online. 

Science education may help restore trust in public health

Citizen scientists were invaluable in collecting data during the COVID-19 pandemic, gathering information on a wide scale through app-based platforms, Arora said. These platforms were repurposed from earlier efforts to collect disease data and hold promise for democratizing public health. 

“We would be blind and tone deaf if we didn’t say that public health lost a lot of its trust,” Arora said. “One step in that direction is to help work collaboratively. But I think another step is to really go back to the grassroots level and look at science education.”

Sophia Ramirez is a senior at Arizona State University and is part of a student newsroom led by The Arizona Republic.

Coverage of the Society of Environmental Journalists conference is supported by Arizona State University’s Cronkite School of Journalism, the University of Arizona, the Nina Mason Pulliam Charitable Trust and the Arizona Media Association.

These stories are published open-source for other news outlets and organizations to share and republish, with credit and links to azcentral.com.