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Epidemics – Like lice, viruses will move very quickly from one species to another in the next 50 years. 15,000 new viral transmissions are expected by 2070 under the influence of +2°C warming compared to the pre-industrial era, warns a new study published Thursday, April 28 in the scientific journal temper nature.
Viral exchanges that will inevitably lead to new zoonotic diseases transmitted from wild animals to humans. A form of infectious disease that we know well now, because it is one of the preferred ways to explain the emergence of COVID-19.
So what is the link with global warming? The researchers explain that zoonotic pathogens are spread by mammals that escape their natural environment. So it is a forced migration due to high temperature. “These geographic shifts may facilitate the sharing of viruses between species that previously had no interaction, which in turn may enhance the transmission of pathogens from wild animals to humans,” they wrote.
Viruses that actually circulate between species
To predict these unlikely interactions, the authors examined the evolution of the habitats of nearly 4,000 mammals under different climatic scenarios by 2070. Even with temperature above 2 °C, the limit should not be exceeded according to the Paris Convention, “One of the study’s authors, Gregory Albury, a researcher at Georgetown University, said, At a press conference, HuffPost Assist.
This phenomenon is already underway, worried scholars. With global warming becoming a reality, species are forced to flee the hottest regions on the planet. Logically, the resulting viral evolution has already begun. To limit the spread, scientists are calling for maximum vigilance: “We should aim to monitor future ‘hot spots’ on the planet.”
Monitoring to limit spread
Tropical Africa and Southeast Asia in particular are on scientists’ radar for three reasons. First, because of the exploitation of the land for intensive agriculture, which brings man closer to animals whose habitat is endangered. Then, these are areas of high human density where epidemics can spread very quickly. Finally, climate change is already visible there, as evidenced by the many droughts.
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 pathogens and capable of harboring viruses that can be transmitted to humans. This animal is the origin of the Covid-19 pandemic, according to several scientific theses. But also many other zoonotic diseases such as Ebola, Nipah or Hendra viruses.
10,000 ‘potentially zoonotic’ viruses are circulating today in mammals. Among them, it is impossible for the authors of this study to determine which future is responsible for upcoming epidemics. Colin Carlson of Georgetown University and the author of this work notes “the risks of spreading coronaviruses and Ebola, but there may be surprises.”
attenuation Climate is not enough
To limit the consequences of these viruses, “reducing greenhouse gas emissions (…) alone cannot reduce the potential for viral involvement due to climate,” the researchers also add. Worse still, slow warming can speed up the emergence of viruses. The slower evolution of climate change allows species to better adapt to it by dispersal. However, the more migratory species there are, the higher the number of first encounters with other species.
It is clear that limiting global warming will not be enough. To prevent this virus exchange from turning into a pandemic,Urman must also reduce activities harmful to the environment, such as intensive farming and the trade in wild animals. “We also have to think about a better health system,” Colin Carlson recalls. The World Health Organization and the United Nations have for years advocated the idea of linking human and animal health and the environment to prevent epidemics.
See also on The HuffPost: Global Warming: At the Poles, Another Catastrophe That Goes Unnoticed