Climate Change Aggravates 58% of Human Infectious Diseases Globally

Because environmental changes — like rising temperatures — are known to expand habitats that are survivable for numerous pathogens, human pathogenic diseases are heavily impacted by the climate crisis and increasingly threaten human health. A new Nature analysis found that over half (58%) of infectious diseases were exacerbated by climate change.

Climate change has been universally understood to impact healthcare. Earlier this year, the AMA declared climate change a public health crisis. Before that, in 2021, the WHO stated that climate change is the most considerable risk to public health.

According to the CDC, an average of 658 people suffer from heat-related deaths and illnesses in the United States annually. Additionally, the WHO estimates that, between 2030 and 2050, climate change will contribute to an additional 250,000 deaths each year.

Heat alone will contribute to deaths and worsening chronic conditions such as asthma. Beyond that, climate change has contributed to a 14.5% increase in Lyme disease rates. Other tickborne illnesses are also further exacerbated by changes in the environment.

Researchers in the publication state, “the compilation of pathogenic diseases aggravated by climatic hazards represent 58% of all infectious diseases reported to have impacted humanity worldwide (that is, out of an authoritative list of 375 infectious diseases documented to have impacted humanity, 218 were found to be aggravated by climatic hazards).”

Globally, warming temperatures have affected about 160 diseases already. Other climate-related events aggravating the spread of pathogenic illness include precipitation, floods, drought, storms, land cover changes, ocean climate change, fires, heatwaves, and sea levels.

In addition to the number of diseases exacerbated by climate change, the researchers could also identify over 1,000 pathways leading to the spread of zoonotic diseases. Simply put, climate change can potentially strengthen pathogens and impair humans' ability to fight them off.

Environmental changes have brought pathogens closer to people by expanding their habitats, and warmer temperatures have driven people toward water activities, putting them closer to risky water-borne pathogens.

In the US alone, approximately $820 billion each year is spent on healthcare costs associated with climate change.

“Such types of disease have the capacity to not only cause illness and death in large numbers of people but can also trigger broader socioeconomic consequences (for example, the cumulative financial costs of the COVID-19 pandemic could amount to $16 trillion for the United States alone). It should be noted that this was not an isolated event; the burden of diseases such as human immunodeficiency virus, Zika, malaria, dengue, chikungunya, influenza, Ebola, MERS, and SARS cause millions of deaths each year, and an inexplicable amount of human suffering,” stated the researchers in the article.

Overall, addressing climate change by implementing sustainable practices in every sector would help alleviate healthcare risks and the financial burden produced by the ongoing and unchecked climate crisis.