Science. With global warming, viruses are transmitted from seals to donkeys

How many viruses are waiting for humans at the onset of climate turmoil? A new study was published last week in the journal temper nature Provides a discouraging start to response. It has already been shown that deforestation and erosion of biodiversity promote the re-emergence of zoonotic vectors, that is, transmission of an animal virus to humans. Global warming of atmospheric temperatures will not only reduce this phenomenon, but the risks are many than it favors, suggests a team of American researchers.

Rising temperatures will lead to new animal migrations

If the news is neither entirely new nor entirely surprising, the article is the first to model the mechanisms that led to this disorder and to determine how often viruses can be transmitted from seals to donkeys. By 2070, scientists say, climate change could lead to more than 15,000 new cases of virus transmission between mammals of various species. Schematically, the process is relatively easy to explain: rising temperatures will cause animals to migrate in search of cooler spaces. The report expects that number “They will congregate in new populations (populations) at high altitudes, in biodiversity hotspots and in areas of high human population density in Asia and Africa.” All will enhance the passage of viruses from one species to another and, in some cases, transmissions of zoonotic viruses. To reach these conclusions, the scientific team modeled the movement of 3,139 species and the new geographical distributions that would result. Then, I calculated the probability of transmission of the virus from one species to another for the first time.

What is the level of risk that this “other” is human? The researchers do not go very far on this point. There are a lot of economic and social factors that come into play, they argue in substance. On the other hand, one thing seems constant: at least 10,000 species of viruses have the potential to infect humans, among the species that today circulate silently among wild mammals.

Several factors reduce this risk

Already suspected of being the source of transmission of the coronavirus to humans, bats remain suspect No. 1 in the study. “Because of their unique ability to dispersal, they account for the majority of new viral posts.” It is considered special in humans. The good news is that many factors reduce this risk, including increased investment in health care and research. Provided you expect it now.

“Our results require great vigilance,” Scholars insist who refuse to talk only in the future. This environmental shift may already be underway, and keeping warming below 2°C over the course of the century will not reduce the future involvement of the virus. » In other words, this process is now inevitable. Our only salvation is to prepare for it.