Greenhouse gas emissions are intensifying climatic hazards, which in turn affect human pathogenic illnesses, caused by infectious agents.
Climate change's impacts on specific groups of pathogens, such as bacteria or viruses, hazards, such as precipitation or floods, or transmission methods, have traditionally been concentrated on previous research.
Since research has focused until now on specific pathogen groups, it has been difficult to quantify the full impact of climate change on pathogenic diseases.
Researchers have recently examined the effects of ten different climatic hazards on various infectious illnesses.
Climate hazards have contributed to 58% of the 375 infectious diseases documented to affect humanity worldwide at some point.
According to Dr. Camilo Mora, a professor in the University of Hawaii at Manoa's Department of Geography and Environment, the recent scientific study, which has appeared in Nature, was quite frightening.
To think that we may truly adapt to climate change, there are simply too many diseases and transmission pathways, and this underscores the need to reduce greenhouse gas emissions globally, according to the author.
Over 200 illnesses were affected by climate changes.
The researchers analyzed over 77,000 papers in search of empirical evidence supporting pathogenic illnesses such as influenza, malaria, and SARS.
Hydrocarbon dangers include:
- extreme precipitation
- sea level rise
- ocean climate change
- land cover change.
There were also included nonmicrobial and nontransmissible agents, including plant and fungal allergens, that are exacerbated by warming, flooding, and storms, and are posing a serious health danger for non-communicable illnesses, such as asthma, skin, or respiratory allergies.
In the end, they identified 286 unique pathogenic illnesses across 3,213 empirical case examples investigated in relation to climatic hazards.
At least one climate danger aggravated 277 illnesses, according to the researchers.
According to them, 54 diseases were largely diminished by certain climatic hazards but elevated by others, and nine were exclusively reduced by climatic hazards.
The researchers concluded that 58% of all infectious diseases that have affected humanity worldwide or 218 out of 375 possible illnesses have been caused by climatic hazards.
They further identified 1,006 distinct pathways in which climatic hazards, via different transmission methods, lead to pathogenic diseases.
Warming influenced 160 illnesses, precipitation impacted 122, and flooding impacted 121.
What are the effects of climate change on illnesses?
Dr. Tristan McKenzie, a postdoctoral researcher at the University of Gothenburg, Sweden, who was one of the authors of the paper, said that climate change could affect human pathogenic diseases.
One reason is that climatic challenges [bring] pathogens closer to humans, while environmental changes [allow] for greater spatial and temporal suitability for vectors and pathogens, according to Dr. McKenzie.
Another approach is that climatic difficulties [bring] humans closer to pathogens, such as climatic difficulties causing the displacement of individuals, which leads to increased contact with pathogens.
Climatic dangers can also enhance pathogens by influencing their capacity to adapt to more severe conditions or by improving environmental conditions that allow for longer periods of vector-pathogen interaction.
According to Dr. McKenzie, this might increase virulence.
Climate influences on the body's ability to cope with infectious agents, and climatic stressors, he added.
Researchers concluded that there is an urgent need to reduce greenhouse gas emissions in order to prevent the harmful effects of climate change on human health.
What do we know yet?
When asked about the limitations of their study, Dr. McKenzie pointed out that while the evidence supports the connection between climate change and illness, the research team did not investigate the effect of climatic hazards on the frequency, severity, or prevalence of specific illnesses.
Ayotte added that while they examined the available literature, there may also be a chance that there are publications that favor examples with negative consequences for common ailments.
Prof. Hans-Otto Poertner, a professor of marine biology and ecological and evolutionary physiology at the Alfred Wegener Institute in Germany, who is not involved in this research, told MNT:
I may not comment on the database or the methodology, but it makes perfect sense to me that [new exposures are possible] because to climate-related shifts in the geographical distribution of species, including pathogens, milder winters, flooding, the collapse of hygiene standards, and the shrinking distance between humans and disease vectors.
The ability of humans to adapt to this challenge lies in the success of emission reductions and the compliance with the ambitious goals of the Paris Agreement, [for example] keeping warming below 1.5 degrees Celsius, according to the expert.
Finally, he noted: This conclusion is identical to those drawn in our Intergovernmental Panel on Climate Change (IPCC) report from considering the hazards in many other industries. A major effort is required!