Climate Hazards Worsen More Than Half of Infectious Diseases

A new study, coauthored by the Nelson Institute’s Jonathan Patz, shows a staggering link between climate change and human disease.

J. Patz Photo
Jonathan Patz

Chances are you’ve known that climate change isn’t just affecting the environment, but human health as well. But until recently, it’s been hard to quantify just how much of a toll climate change is having on human health and disease. A new study published by the University of Hawaii and coauthored by Jonathan Patz, Nelson Institute professor and John P. Holton Chair in Health and the Environment, found that a staggering 58 percent of human infectious disease has been exacerbated by climate hazards. 

“The sheer number of pathogenic diseases and transmission pathways aggravated by climatic hazards reveals the magnitude of the human health threat posed by climate change and the urgent need for aggressive actions to mitigate GHG emissions,” the study reports.

Climatic hazards are major climate-related events — like droughts or floods — that are directly linked to greenhouse gas emissions. Some climate hazards bring humans closer to pathogens (think Legionnaires’ disease, which is spread through mist and water supplies), whereas other hazards bring pathogens closer to people (like increased warming creating more habitable climates for Lyme-disease–carriers). 

“If climate is changing, the risk of these diseases are changing,” Patz told the Associated Press. There may even be some links between the changing climate and COVID. It’s too early to say for certain, but this study has certainly raised some questions. “Coronaviruses are carried by bats,” Patz told MSNBC. “If you disrupt the habitat of bats and force them to migrate or to become in higher density and more transmission from bat to bat [occurs],” he explained, “that can lead to an increased risk of transmission and passage of these viruses from bats to humans.” There are also socioeconomic factors when it comes to climate change and COVID, such as heat waves that send people — typically poorer populations, Patz says — to congregate in cooling centers, increasing their risk of transmission.

“I’ve been working on this issue for more than 25 years. It really is extremely important,” Patz says. “ The climate crisis is a health crisis.”

Read the full study here.