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EPIDEMIC. Like lice, viruses will move very quickly from one species to another over the next fifty years. By 2070, 15,000 new cases of virus transmission are expected due to a warming of +2°C compared to the pre-industrial era, warns a new study published this Thursday, April 28, in a scientific journal. Nature.
Viral exchanges that will inevitably lead to new zoonoses, diseases transmitted from wild animals to humans. A form of infectious disease that we now know well because it is one of the preferred ways to explain the emergence of Covid-19.
So what is the connection to global warming? The researchers explain that zoonotic pathogens are spread by mammals leaving their natural habitat. Therefore, this is a forced migration due to rising temperatures. “These geographic shifts may facilitate the spread of viruses between species that have not previously interacted with each other, which in turn may facilitate the transmission of pathogens from wildlife to humans,” they write.
Viruses that are already circulating between species
To predict these incredible interactions, the authors studied the evolution of the habitats of nearly 4,000 mammals under various climate scenarios by 2070. Even with warming below 2°C, the limit that cannot be crossed under the Paris Agreement,it will happen, and there is no going back,” says Georgetown University researcher Gregory Albury, one of the authors of the study. at a press conference where HuffPost provided assistance.
The phenomenon is even already underway, worried scientists. With global warming already a reality, species are forced to flee from the hottest spots on the planet. Logically, the resulting viral evolution has already begun. To limit the spread, scientists are calling for maximum vigilance: “We must aim to monitor future “hot spots” on the planet.”
Monitor to limit spread
Tropical Africa and Southeast Asia are in the focus of scientists for three reasons. Firstly, because of the exploitation of the land for intensive agriculture, which brings people closer to animals whose habitat is disturbed. Then there are areas of high population density where epidemics can spread very quickly. Finally, climate change is already visible there, as evidenced by numerous episodes of drought.
Another point of vigilance, species that can incubate viruses transmitted to humans. The bat is well monitored by scientists. It is a host valued by pathogenic agents and capable of containing viruses that can be transmitted to humans. According to several scientific theses, this animal is the cause of the Covid-19 pandemic. But also many other zoonotic diseases such as Ebola, Nipah or Hendra.
There are 10,000 “potentially zoonotic” viruses circulating in mammals today. Among them, the authors of this study cannot identify the future responsible for the coming epidemics. “There are risks of the spread of coronavirus and viruses like Ebola, but there may be surprises,” said Colin Carlson of Georgetown University, as well as the author of this work.
damping the climate is not enough
The researchers also add that in order to limit the effects of these viruses, “cutting greenhouse gas emissions (…) alone cannot reduce the likelihood of climate-driven viruses spreading.” Worse, slow warming can even accelerate the emergence of viruses. The slower evolution of climate change allows species to better adapt to them through dispersal. However, the more species migrate, the greater the number of first encounters with other species.
It is clear that limiting global warming will not be enough. To prevent these virus exchanges from escalating into a pandemic,Urman must also cut back on environmentally damaging activities such as intensive farming and the wildlife trade. “We also need to think about improving the healthcare system,” recalls Colin Carlson. The WHO and the UN have for years championed the idea of linking human, animal and environmental health to prevent pandemics.
Look also at The HuffPost: Global warming: at the poles another disaster that went unnoticed