Climate change “could have played a key role in the coronavirus pandemic,” according to a study


Man-made climate change “may have played a key role” in the coronavirus pandemic. This is the finding of a new study that examined how climate changes have changed the forests of Southeast Asia and led to an explosion of bat species in the region.

The researchers found that due to changes in vegetation over the past 100 years, another 40 bat species have moved to the region and carry 100 more species of bat coronavirus with them. Bats are known carriers of coronavirus, with different species carrying thousands of different species. Many scientists believe that the virus triggered the global COVID-19 pandemic originated in bats in southern China’s Yunnan Province or neighboring areas before interbreeding with humans.

These results have made scientists concerned about the likelihood that climate change will make future pandemics more likely.

“If bats with around 100 coronaviruses expand into a new area due to climate change, it is likely that it will increase the likelihood that a coronavirus harmful to humans is present, transmitted or developed in that area.” explains Dr. Robert Beyer, lead author of the study and a researcher at Cambridge University.

Visitors look into the abandoned Wanling Cave in southern China’s Yunnan Province on December 2, 2020. Contact between bats and humans is alarming scientists as a potential source of disease outbreaks.

Ng Han Guan / AP

Researchers used climate records to create a map of the world’s vegetation as it was a century ago. Using knowledge of the types of vegetation required by different bat species, they determined the global distribution of each species in the early 1900s.

They then compared this to current bat populations. Their results show that the biodiversity of bats – the number of different bat species found in a given area – thrived more in this pocket of Southeast Asia than anywhere else on earth.

The following picture from the study shows how forests in southern China, Myanmar, and Laos have changed over the past century, improving the habitat preferred by bats and increasing species reproduction. This pronounced porthole in the region shows the increase in the biodiversity of bats. (The study does not take into account the total population size, only the diversity of bat species in the region.)


Dr. Robert Beyer

According to the authors, climate changes such as temperature rises, sunlight and carbon dioxide, which affect the growth of plants and trees, have altered vegetation in southern China, turning tropical bushland into tropical savannah and deciduous forest. According to the authors, this type of forest is more suitable for bat species.

The study calls this area in Southeast Asia “a global hotspot” for bat species and points to genetic data suggesting that SARS-CoV-2, the virus that causes COVID-19, originated in this region.

According to the authors, this is the first evidence that climate change may have played a direct role in causing the virus.

“We estimate that climate change in the last century has led to a significant increase in the number of bat species in the location where SARS-CoV-2 is likely to have originated,” Beyer said. “This surge suggests a possible mechanism by which climate change may have played a role in causing the pandemic.”

A research team from the World Health Organization was finally allowed in Wuhan, China, in January to investigate the source of the outbreak that was first reported in that city a little over a year ago. A leading theory among scientists is that the virus originates from bats before jumping to humans, possibly through an animal host such as Pangolins. Some of the first cases were associated with a wildlife market in Wuhan. But so far this is just a theory, and researchers are I’m just starting to do some research the origins of the pandemic.

WHO investigators begin work in Wuhan, China


Dr. Rick Ostfeld, an expert in disease ecology at the Cary Institute of Ecosystem Studies in Millbrook, New York, finds the research compelling, although he does not agree with all of the conclusions. It is not surprising that climate change has changed forests and bat communities. He also agrees with the study’s authors that movement of animals can contribute to the spread of viruses.

“The movement of animal communities in a region can have a profound effect on disease transmission by exposing animal owners to new pathogens,” he said.

But he is careful when drawing conclusions beyond that.

“The connection with the development of corona viruses is highly speculative and unlikely,” said Ostfeld.

“What the study appears to be getting wrong is the assumption that the increasing diversity of bats (which they posit) leads to an increased risk of a bat-borne virus jumping on humans. It just isn’t the case,” he said . “The vast majority of bats are harmless to humans – they don’t contain viruses that can make us sick. So adding more of these species doesn’t increase the risk.”

Kate Jones, Professor of Ecology and Biodiversity at University College London, is also a little cautious. She said: “Climate change certainly plays a role in changing the species distribution to increase the ecological risk. However, the risk of overflow is a complex interplay not only of ecological danger, but also of human exposure and vulnerability.”

Beyer agrees that “caution is warranted” when it comes to associating climate change directly with the pandemic, since, as he explains, it assesses the extent to which climate change is assessed to a stage between a bat carrying the virus , and has contributed to an infected human will require a lot more work. In particular, this includes the use of epidemiological models that analyze the interactions between different species and viruses over space and time.

While it is common knowledge that exponential growth in human population and our rampant exploitation of the natural world, like Destroying forests and extension of the Pet tradeis Increase the risk of having contagious pathogens can make the jump from animals to people more easily, it was less clear to what extent Climate change factors in.

Virus outbreak animal origins
Health officials are investigating bats to be seized and killed at a live animal market in Solo, Central Java, Indonesia following the coronavirus outbreak on March 14, 2020.


However, over the past century many ecosystems have warmed – sometimes by several degrees – due to man-made climate change, and rainfall patterns have shifted, with some areas getting less and others more. These ecosystem changes are changing the habitat of many species and bringing more species into contact with each other, potentially making it easier for viruses to spread.

When asked about the climatic links to the spread of disease, most experts agree that there are effects, but some say that direct human actions such as deforestation, development or animal husbandry on an industrial scale are a bigger problem.

“The increase in human population, human movement and the deterioration of the natural environment from agricultural expansion may turn out to play more important roles in understanding the SARS-CoV-2 spillover process,” said Jones.

Ostfeld noted, “We can predict which wildlife species are most likely to carry pathogens that can make humans sick. These generally thrive when we replace natural habitats (like forests and savannas) with agriculture, housing developments, and shopping malls.”

Beyer does not question these assessments. “We absolutely agree that the expansion of urban, farmland and hunting areas into natural habitats is a major driver of zoonotic disease transmission – it is they that bring many pathogen-bearing animals and humans in contact,” he said.

Given the results of his research on how the climate has changed the region, Beyer believes that climate change can be a major driver.

“Climate change can drift where these animals are. In other words, climate change can bring pathogens closer to humans. It can also move one species that carries a virus into the habitat of another species that the virus then moves to can jump – a step that might not have happened without climate change, and this could have significant long-term consequences for the further development of the virus. “

Beyer also sees climate connections that go beyond the increase in bat species. “In some cases, higher temperatures can increase viral loads in species, making it more likely that the virus will be transmitted,” he said. “And: Elevated temperatures can increase the tolerance of viruses to heat, which in turn can increase infection rates, since one of our primary defense systems against infectious diseases is to increase our body temperature (fever).”

While there are some concerns in the scientific community about the specific impacts of climate change on the current coronavirus pandemic, there is widespread agreement that climate change will be a growing driver of emerging infectious diseases and pandemics in the future.

“Climate change will shift the geographical distribution of pathogenic species so that they overlap with species with which they have not previously overlapped,” Beyer said. “These new interactions offer dangerous opportunities for viruses to spread and develop.”

“Climate change is definitely an important driver for the development and spread of diseases. It can increase transmission in various ways,” said Ostfeld. “So, yes, climate change is definitely affecting me as a driver of future pandemics.”

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