Over half of human infectious diseases impacted by climate change, says study
Over half of human infectious diseases impacted by climate change, says study
ISLAMABAD, (Online) - Greenhouse gas emissions are intensifyingTrusted Source climatic hazards, which in turn affect human pathogenic diseases- conditions caused by infectious agents.
Previous studies have typically concentrated on the effects of climate change on specific groups of pathogens, such as bacteria or viruses, hazards, such as precipitation or floods, or transmission types such as via food or water.
As research until now has generally focused on specific groups of pathogens, it has not been possible to quantify the total threat of climate change on pathogenic diseases.
Recently, researchers analyzed the effects of ten different climatic hazards on various infectious diseases.
They found that 58% of the 375 infectious diseases documented to affect humanity worldwide have been aggravated by climatic hazards at some point.
“Given the extensive and pervasive consequences of the COVID-19 pandemic, it was truly scary to discover the massive health vulnerability resulting as a consequence of greenhouse gas emissions,” said Dr. Camilo Mora, professor in the Department of Geography and Environment at the University of Hawaii at Manoa, and lead author of the recent scientific analysis, which appears in NatureTrusted Source.
“There are just too many diseases and pathways of transmission for us to think that we can truly adapt to climate change. It highlights the urgent need to reduce greenhouse gas emissions globally,” he added.
Climate hazards influenced over 200 diseases
For the analysis, the researchers examined over 77,000 studies in search of empirical examples of climatic hazards impacting pathogenic diseases, such as influenza, malaria, and SARS.
Climatic hazards included:
• warming
• drought
• heatwaves
• wildfires
• extreme precipitation
• floods
• storms
• sea level rise
• ocean climate change
• land cover change.
The researchers included microbial agents as well as nonmicrobial and nontransmissible agents, including plant and fungal allergens, which are aggravated by warming, floods, and storms, and are becoming a serious health problem for non-communicable diseases, including asthma, skin or respiratory allergies.
In the end, they identified 286 unique pathogenic diseases across 3,213 empirical case examples studied in relation to climatic hazards.
They found that 277 diseases were aggravated by at least one climate hazard.
They further found that 54 diseases were diminished by some climatic hazards yet elevated by others, and nine were exclusively diminished by climatic hazards.
Altogether, the researchers noted that 58% of all infectious diseases reported to have impacted humanity worldwide — or 218 out of 375 possible diseases — have been aggravated by climatic hazards.
They further identified 1,006 unique pathways in which climatic hazards, via various modes of transmission, lead to pathogenic diseases.
They noted that warming affected 160 diseases, precipitation affected 122, and flood, 121.
How does climate change influence disease?
When asked how climate change might aggravate human pathogenic diseases, Dr. Tristan McKenzie, postdoctoral researcher in the Department of Marine Sciences at the University of Gothenburg, Sweden, and one of authors of the analysis, noted that they found four main mechanisms through which climatic hazards interact with pathogens and aggravate human disease.
One is that “climatic hazards [bring] pathogens in closer proximity to humans — for example, environmental changes [allow] for increased spatial and temporal suitability for vectors and pathogens, Dr. McKenzie told us.
Another is that “climatic hazards [bring] humans closer to pathogens — examples include climatic hazards forcing the displacement of people that lead to increased contact with pathogens,” he continued.
Climatic hazards also enhance pathogens by influencing their ability to adapt to more extreme conditions or by enhancing “environmental conditions that allow for longer periods of vector-pathogen interaction.”
