UNIVERSITY OF CAMBRIDGE
Global greenhouse gas emissions over the last century have made southern China a hotspot for bat-borne coronaviruses, by driving growth of forest habitat favoured by bats.
A new study published today in the journal Science of the Total Environment provides the first evidence of 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 study has revealed large-scale changes in the type of vegetation in the southern Chinese Yunnan province, and adjacent regions in Myanmar and Laos, over the last century. Climatic changes including increases in temperature, sunlight, and atmospheric carbon dioxide – which affect the growth of plants and trees – have changed natural habitats from tropical shrubland to tropical savannah and deciduous woodland. This created a suitable environment for many bat species that predominantly live in forests.
The number of coronaviruses in an area is closely linked to the number of different bat species present. The study found that an additional 40 bat species have moved into the southern Chinese Yunnan province in the past century, harbouring around 100 more types of bat-borne coronavirus. This ‘global hotspot’ is the region where genetic data suggests SARS-CoV-2 may have arisen.
“Climate change over the last century has made the habitat in the southern Chinese Yunnan province suitable for more bat species,” said Dr Robert Beyer, a researcher in the University of Cambridge’s Department of Zoology and first author of the study, who has recently taken up a European research fellowship at the Potsdam Institute for Climate Impact Research, Germany.
He added: “Understanding how the global distribution of bat species has shifted as a result of climate change may be an important step in reconstructing the origin of the COVID-19 outbreak.”
To get 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. Then they used information on the vegetation requirements of the world’s bat species to work out the global distribution of each species in the early 1900s. Comparing this to current distributions allowed them to see how bat ‘species richness’, the number of different species, has changed across the globe over the last century due to climate change.
“As climate change altered habitats, species left some areas and moved into others – taking their viruses with them. This not only altered the regions where viruses are present, but most likely allowed for new interactions between animals and viruses, causing more harmful viruses to be transmitted or evolve,” said Beyer.
The world’s bat population carries around 3,000 different types of coronavirus, with each bat species harbouring an average of 2.7 coronaviruses – most without showing symptoms. An increase in the number of bat species in a particular region, driven by climate change, may increase the likelihood that a coronavirus harmful to humans is present, transmitted, or evolves there.
Most coronaviruses carried by bats cannot jump into humans. But several coronaviruses known to infect humans are very likely to have originated in bats, including three that can cause human fatalities: 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 to SARS-CoV-2. The virus is likely to have jumped from bats to these animals, which were then sold at a wildlife market in Wuhan – where the initial human outbreak occurred.
The researchers echo calls from previous studies that urge policy-makers to acknowledge the role of climate change in outbreaks of viral diseases, and to address climate change as part of COVID-19 economic recovery programmes.
“The COVID-19 pandemic has caused tremendous social and economic damage. Governments must seize the opportunity to reduce health risks from infectious diseases by taking decisive action to mitigate climate change,” said Professor Andrea Manica in the University of Cambridge’s Department of Zoology, who was involved in the study.
“The fact that climate change can accelerate the transmission of wildlife pathogens to humans should be an urgent wake-up call to reduce global emissions,” added Professor Camilo Mora at the University of Hawai’i at Manoa, who initiated the project.
The researchers emphasised the need to limit the expansion of urban areas, farmland, and hunting grounds into natural habitat to reduce contact between humans and disease-carrying animals.
The study showed that over the last century, climate change has also driven increases in the number of bat species in regions around Central Africa, and scattered patches in Central and South America.
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This assumes the Virus originated in a Chinese bat. Nobody knows for sure. Or do they?
Batpoop.
A geochemist, at my own expense, I made 5 visits to Yunnan province and travelled widely there, sometimes with my wife. I even had birds nest soup with the makings gathered from a large bat cave next to the restaurant. Our hobby interest in the yellow-flowered camellia species then being let known to the world and rhododendrons in general led us to have 2 graduate botanist interpreters from the world-famous Kunming Institute of Botany. Business wise, I had been involved with major resources development including large forestry plantations and paper mills in Australia.
In respect of the Cambridge paper here, there are some unsaid factors. One is that some changes to native vegetation started in the late 1890s as Chinese gold rush workers returned home and planted seeds of good Australian trees like Eucalyptus robusta (“Silky Oak” or “Swamp Mahogany”). These are now widespread through the province and often line city streets of the capital Kunming. Later. as China developed a paper industry, large plantations appeared in the landscape around 1985 and are still happening. One of the plantation trees we often saw, for whatever uses, was the Australian blue gum, E. globulus. The point is that global warming was far from the only influence on vegetation type changes.
Another factor was population growth in Yunnan. In 1901 (the start of one of their study periods), much of the landscape was unable to be settled away from sources of natural water because it was so mountianous. With the advent of electricity and pumps, habitation went increasingly uphill and removed a lot of native forest. The flat land farming was intensive from years ago, but it had to expand and use more irrigation as the population grew over the last century. More changes not driven by global warming.
The Yunnan temperature records for the past century were affected as to quality and scope by the Industrial Revolution. To this day I do not know if Yunnan warmed at all in the last century and I doubt if others know either. The authors show a hard-to-read graph comparing monthly T for 30 years starting 1901 with 30 years starting 1990 but there is little temperature change to be seen.
On the topic of species relocation from global warming, they refer readers to Parmesan 2006, a paper on butterflies slammed by critics for blatant cherry picking.
Overall, this reads like another sausage machine paper from Germany’s finest activism centre at Potsdam, with the usual technique of ignoring inconvenient objections and using imagination (with easy, unsupported sentences such as “estimated climate change-driven increase of around 40 bat species across the region “ to roll over proper science and lack of detailed knowledge with weasel words and approximations. Quite a shameful effort, really. Geoff S
“To get 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. Then they used information on the vegetation requirements of the world’s bat species to work out the global distribution of each species in the early 1900s.”
In other words, they didn’t collect the vegetation data. Instead they created it using models based on whatever limited and poor-quality weather data they could find for a remote backward region over 100 years ago.
RDW,
When you travel Yunnan with botanists, they show you what is named “original vegetation” or similar, very often in the grounds of long-time monasteries. Step outside the monastery walls and you see much different tree assemblages. Some places, like the top of Zi Xi mountain, arenear original because there are many old monasteries there and the whole cap of thiese hills is a collection of what was there before. Such preserved sites are not common. It is hard to imagine the value of the methods these authors use, as you note.
I thought it was racist to suggest the SARS-CoV-2 virus came from China? I was amazed through this to discover that Chinese are a race as well – I always though it was just a place???
The SARS-CoV-2 virus evolved because it was somehow beneficial to do so – for the virus. It has nothing to do with climate change, or warming, or China.
Bats have a very ramped up immune system, so when a virus evolves that does well in a bat and then finds a way to get into a human it is going to propagate quickly and likely be very dangerous. Eventually it will probably evolve into a less dangerous form in the human population because killing people is not helpful to its spread – but there is no guarantee of this. An RNA based virus that propagates quickly is also more likely to mutate into forms that can keep the virus spreading – in some cases forever like a FLU virus.
You might be able to blame the bats for SARS-CoV-2 (at least their immune systems), but you certainly cannot blame Climate Change. That is just ridiculous and sad.
Waffle word fantasies.
The only thing that hearing the words “climate change” actually trigger are deep seated needs for engorgement at the climate funding trough.
And I thought bat populations were declining due to climate change…
“populations of many bat species are declining because of threats such as climate change, habitat loss and degradation, hunting and emerging disease”
https://www.cambridge.org/core/journals/oryx/article/bat-conservation-in-china-should-protection-of-subterranean-habitats-be-a-priority/4AD4FC8E1F088AF7498DE342B2F019F3
No “natural mechanism” can generate a 4-5 aminoacid (12-15 base pairs) optimized furin cleavage site in a viral genome. See: https://articles.mercola.com/sites/articles/archive/2020/05/19/smoking-gun-proving-sars-cov-2-was-lab-created.aspx
This virus is a complete stand-alone among other members of this viral family. Ask Fauci and the people of the viral research labs in Wuhan what happened (if they haven’t been “disappeared”). Apparently one even goes as far to even create new Journals “Science of the Total Environment?” to publish even the most face palm provocating rubbish. They’re not following the science, they’re destroying it. Even top journals are playing a role in this: https://childrenshealthdefense.org/defender/medical-journal-cover-up-origins-sars-cov-2/?utm_source=salsa&eType=EmailBlastContent&eId=2a798b16-0fa4-459f-be4c-0c8246d786da
It has more to do with the Chinese hunting bats for food and then transporting them into highly populated urban areas.
saw this at science alert n thought it was crap
2nd read and i still do
some bats like trees but it seems the main covid carriers prefer caves
isnt it odd the super stressed ones in usa who all got whitenose fungus etc havent managed to spread anything around?
people tramping around all the caves checking bats spread the fungus too, Eu copped it as well suspect brought in BY the same “science types’
its definitely seeming tropical and warm clime ones are culprits
ie hendra in aus ,nipah in indonesia and MERS in mid east
This is confirmed by Luisa Neubauer (German Greta Thunberg handler) in a newly statement.
Therefore we now know for certain that the plant food CO2 is causing SARS-CoV-2. It is peer reviewed by Luisa.
Hmm – do I need to add SARC tag?
https://t.me/mellemtiden/112
Yes, climate change causes wet markets to co-locate next to the only SARS research lab in Asia. The model says so.
Now give me my promotion and next grant.
The Great Bat Chernobyl is upon you and Biden will shower you with free money for the next four years.
Just found that about the CC attribution to the bat increase:
Source