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London, February 6: Cambridge University researchers have revealed a mechanism by which climate change could have played a direct role in the emergence of SARS-CoV-2, the virus that caused the Covid-19 pandemic.
The new study published in the journal Science of the Total Environment revealed large-scale changes in vegetation type in Yunnan province in southern China and adjacent regions in Myanmar and Laos over the past century.
Climate changes, including increases in temperature, sunlight, and atmospheric carbon dioxide, which affect the growth of plants and trees, have changed natural habitats from tropical scrub to tropical savannas and deciduous forests.
This created a suitable environment for many species of bats that predominantly live in forests.
The amount of coronavirus in an area is closely related to the number of different species of bats present.
The study found that another 40 species of bats have moved to Yunnan Province in southern China in the past century, harboring around 100 more types of bat-borne coronavirus.
This ‘global hotspot’ is the region where genetic data suggest that SARS-CoV-2 may have emerged.
“Climate change over the past century has made the habitat in southern China’s Yunnan Province suitable for more species of bats,” said Robert Beyer, a researcher at the University of Cambridge and first author of the study, He has recently done a European Research Fellowship at the Potsdam Institute for Climate Impact Research, Germany.
“Understanding how the global distribution of bat species has changed as a result of climate change can be an important step in reconstructing the origin of the Covid-19 outbreak,” he added.
To obtain their results, the researchers created a map of the world’s vegetation as it was a century ago, using records of temperature, precipitation and cloud cover.
They then used information on the vegetation requirements of the world’s bat species to calculate the global distribution of each species in the early 20th century.
Comparing this to current distributions allowed them to see how the ‘species richness’ of bats, the number of different species, has changed around the world over the last century due to climate change.
“As climate change altered habitats, species left some areas and moved to others, taking their viruses with them. This not only altered the regions where viruses are present, but likely allowed for new interactions between animals and viruses, causing more harmful viruses to be transmitted or evolved, ”said Beyer.
The world’s bat population carries around 3,000 different types of coronavirus, and each bat species harbors an average of 2.7 coronaviruses, most showing no symptoms.
An increase in the number of bat species in a particular region, driven by climate change, can increase the likelihood that a coronavirus harmful to humans is present, transmitted or evolved there.
Most bat-borne coronaviruses cannot affect humans. But it is highly likely that several coronaviruses known to infect humans have originated in bats, including three that can cause human deaths: Middle East respiratory syndrome (MERS) CoV and severe acute respiratory syndrome (SARS) CoV- 1 and CoV-2.
The region identified by the study as a hotspot for a climate-driven increase in bat species richness is also home to pangolins, which are suggested to have acted as intermediate hosts for SARS-CoV-2.
The virus likely passed from bats to these animals, which were later sold at a wildlife market in Wuhan, where the initial human outbreak occurred.
The researchers echo calls from previous studies urging policy makers to recognize the role of climate change in viral disease outbreaks and to address climate change as part of Covid-19 economic recovery programs.
Disclaimer: This story is automatically generated from the IANS service.
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