Studies have shown that warming is one of the drivers of virus spillover
As the planet heats up, many animals will be forced to migrate to new areas in search of suitable habitats, which means they may transmit parasites and various viruses to other "first-time" new species. Scientists warn that warming causes animal habitats to change, increasing the risk of "virus spillover" and posing a greater epidemic threat to humans.
For example, as the climate warms, malaria-transmitting mosquitoes expand their range of life to warming areas, posing a greater threat to human health. According to a study published in Nature on April 28, the geographic extent of thousands of mammals will change by 2070 due to climate and land-use changes, which will drive thousands of viruses to spread between different mammals. Even at relatively low levels of global warming, projections say at least 15,000 cross-species transmission events of one or more viruses will occur over the next 50 years. Among them, bats in Southeast Asia are the biggest threat, and they are most likely to spread the virus to other mammals.
Studies have shown that:
Animals migrate over the next 50 years
It will result in at least 15,000 cross-species transmissions
The study notes that at least 10,000 viruses capable of infecting humans are spreading "silently" among wildlife populations. The history of epidemics suggests that viral cross-infection between humans and animals is uncommon, but as more habitats are destroyed by agricultural and urban expansion, so does the opportunity for humans to reach wild species. In addition, as the climate warms, animals living in warmer regions will expand their habitat range. These changes have "created new opportunities" for viral transmission between previously geographically isolated wildlife species. Viruses not only infect new hosts, but also can cause new types of viruses and entirely new diseases.
"We know species are moving, and when they move, they have the opportunity to share in the spread of the virus." Colin Carlson, a biologist at Georgetown University in the United States and co-author of the study, said.
To understand how viruses are transmitted between species, Dr. Carlson and his colleagues used a systematic geography model of mammalian-viral networks to model the potential spillover effects of viruses in a warming world. The team first predicted how 3139 species of mammals would change their range of activity between now and 2070.
Studies show that even in the most optimistic scenario – with global warming of less than 2°C – these moving mammals could lead to at least 15,000 cross-species transmission events of one or more viruses. Another co-author, Gregory Albury, an expert in disease ecology at Georgetown University, said, "This study provides more indisputable evidence that the world will not only be hotter, but also sicker in the coming decades." ”
Infectious disease researchers collect bat samples outside the cave
The temperature increase will be controlled within 2 °C within this century
Nor does the risk of viral spillage decrease much
The study also notes that bats pose the greatest risk of "viral spillover." The researchers found that bats in Southeast Asia are particularly vulnerable to climate change. As of now, many bat species in the area are only active in small areas and do not have much contact with each other. But the study notes that as the planet warms, these bats, which have the ability to fly long distances, will quickly fly to suitable new habitats and may transmit the virus to other species encountered.
Bats, on the other hand, are also a threat to the number of viruses carried by the species. Previous research has estimated that more than 3,200 coronaviruses have spread in bat populations. And over the past few decades, the number of cases of coronaviruses and other respiratory diseases believed to have come from bats and birds has skyrocketed. If these bats "set foot" in a wider range of habitats, the likelihood of a new epidemic erupting and spreading will increase dramatically.
About 3,200 coronaviruses have spread in bats
The biological chains that trigger epidemics can be long and delicate, but the study emphasizes that climate change is "shaking the core of ecosystems, and that this ecological shift may have already begun." If the warming is controlled within 2°C within this century, the risk of virus spillage will not be reduced much. Therefore, the researchers say, countries should combine virus detection monitoring with animal movement and biodiversity surveys as soon as possible, especially in hotspots with the most zoonotic infectious diseases and in areas experiencing rapid warming.
"(Virus spillover) is happening and cannot be prevented even in the most optimistic climate change scenarios." We need to build more sanitation infrastructure to protect animals and humans. Researcher Albury said.
Red Star News reporter Ding Wen
Edited by Pan Li
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