New study shows warmer temperatures allow bugs to thrive, increasing risk
A major new study published today in the journal Nature Climate Change has found strong evidence linking rising global temperatures to an increase in diarrheal diseases across the world. Researchers at the University of Surrey examined decades worth of data and concluded that climate change is creating ideal conditions for bacteria and other disease-causing pathogens to proliferate, leading to more frequent and severe diarrhea outbreaks globally.
Key findings show 2-10% increase in diseases per degree of warming
The peer-reviewed study analyzed reported cases of diarrheal illness from 1990-2016 in over 700 locations across the globe, along with detailed temperature data for each area. Their statistical models found a consistent correlation between warmer ambient temperatures and increased rates of diarrheal diseases such as cholera, rotavirus, and E. coli.
On average, the research showed a 2-10% increase in diarrheal diseases per 1 degree Celsius (1.8 degrees Fahrenheit) of warming depending on the location. This effect was more pronounced in areas with higher baseline temperatures in tropical regions and during months with higher than average temperatures.
Dr. Anne Kepple, the lead author of the study, emphasized that even small changes in temperatures can have an outsized effect by creating ideal incubators for disease-causing microbes to multiply faster. Areas lacking access to clean water and sanitation face the biggest risk.
Millions of lives already impacted each year
Diarrheal diseases are already one of the leading causes of sickness and death globally, estimated to kill over 2 million people per year, many of them children. These new findings indicate that the diarrheal disease burden could significantly worsen in the coming decades as the planet continues to warm.
By analyzing future climate projections, the models suggest there could be tens of millions more cases of diarrheal illness annually by 2050 across Africa, South Asia, and South America if rapid action isn’t taken to mitigate climate change. Other researchers praised the significance of the study:
“This rigorously conducted study adds to growing evidence that climate change could reverse decades of progress made in reducing rates of infectious disease. It underscores the urgent need to cut emissions globally.” (Dr. Jonathan Patz, University of Wisconsin)
| Location | Projected Additional Diarrhea Cases by 2050 |
|---|---|
| Africa | 12 million |
| South Asia | 17 million |
| South America | 5 million |
Cholera and rotavirus most influenced by temperature
When examining different kinds of pathogens, the study found that cholera and rotavirus infections were the most temperature sensitive diseases. Cholera cases in particular could rise sharply in vulnerable areas if action isn’t taken.
Warmer coastal water temperatures create ideal conditions for cholera bacteria (Vibrio cholerae) to thrive, including algal blooms which the bacteria uses to grow and multiply exponentially. Cholera is mainly spread by contaminated food and water sources.
Meanwhile, rotaviruses are the leading cause of severe diarrhea in infants and children globally. The researchers found a tipping point at warmer temperatures where rotavirus transmission rates start to take off. Just a few degrees of warming allows these highly contagious viruses to survive longer and spread farther geographically through human interaction.
Climate connection now firmly established
This University of Surrey-led report provides some of the most concrete evidence to date on the link between rising global temperatures and increased risk of diarrheal diseases. Though extreme weather events like floods can also contribute, the study isolated ambient air and water temperature as a factor that by itself is influencing disease levels across many regions.
This builds on previous research also showing climate change as a factor increasing cases of malaria, dengue fever, Zika virus, and other infectious diseases. Experts say that understanding all the ways global warming worsens public health threats is crucial for policy makers to prioritize emissions reductions and climate change mitigation globally.
In the meantime, the world’s poorest and most vulnerable populations face being impacted the most by these alarming trends of more frequent disease outbreaks in a warming world. Along with emissions cuts, increased investment in clean water infrastructure, sanitation systems, and public health programs are urgently needed to help developing regions adapt.
Next steps: Mitigation and disease surveillance key
While this research focused on quantifying the observed linkage between warmer temperatures and diarrheal disease prevalence globally, follow up studies will examine these effects in more localized contexts. Combining climate projections, environmental factors, and disease surveillance data could help predict changing health risk profiles in certain areas as temperatures rise.
More precise monitoring and modeling could aid governments in being proactive by directing resources and medical aid to at-risk locations before outbreaks occur. Ongoing surveillance along with programs increasing access to clean water, vaccines, proper nutrition, and sanitation will remain vital.
Ultimately experts agree the most important action that must be taken is rapidly reducing greenhouse gas emissions worldwide. Mitigating human-caused climate change is the only way to slow and eventually halt the worsening impacts to public health and wellbeing from a warmer planet. This study provides further impetus for world leaders to take much bolder action cutting carbon pollution at the urgently needed scale.
To err is human, but AI does it too. Whilst factual data is used in the production of these articles, the content is written entirely by AI. Double check any facts you intend to rely on with another source.
