February 5, 2021

expert reaction to study of climate change, bats and SARS-CoV-2

A study published in Science of the Total Environment looks at the emergence of SARS-CoV-1 and SARS-CoV-2, climate change and shifts in global bat diversity.

Prof Paul Valdes, Professor of Physical Geography at the Cabot Institute for the Environment, University of Bristol, said:

“The paper is interesting but there are many untested aspects of their conclusions, especially since we are still debating the origins of covid. They show that climate change may have had a small impact on the biodiversity of bat species in Yunnan but this is more than 2000km away from Wuhan and the link between the two regions is not discussed. Moreover, habitat loss is likely to have played a much larger role in biodiversity change than any small effect from climate change and this is not incorporated into their model. It therefore seems premature to conclude that climate change has had a big effect on the emergence of SARS-CoV-2.”

Prof Kate Jones, Professor of Ecology & Biodiversity at University College London, said:

“I think this is an interesting study and climate change certainly has a role to play in changing species distributions to increase ecological hazard. However, spillover risk is a complex interplay of not only ecological hazard but human exposure and vulnerability. It may turn out that increases in human populations, human movement and degrading natural environments through agricultural expansion have a more important role to play in understanding the spillover process of SARS-CoV-2.”

Dr Matthew Struebig, Reader in Conservation Science at the University of Kent, said:

“It’s an interesting approach – the use of statistical models to predict vegetation cover from climate data is well established. However, I’m sceptical of the link between climate change and changes to bat distributions proposed here.  There are too many assumptions for me to conclude that climate change could have increased the likelihood of the pandemic occurring in this way.

“The analysis relies on IUCN distribution information which is patchy at best, and not ideal for these kinds of analyses. As a member of the IUCN Bat Specialist Group I can tell you that the information we have available to map distributions is grossly insufficient. Many species are not fully assessed, and too many are so poorly known they are only documented as a few dots on a map. Very little is known about optimum or preferred vegetation types  – especially in the region highlighted in this study. For many species, the extent of occurrence is much more likely to be underestimated due to insufficient survey information, but also unresolved taxonomy. For example, substantial numbers of species have only recently been described in mainland SE Asia, with most being splits from other widely-distributed species (especially in Myanmar and Laos). You can therefore begin to see how this could really skew an analysis that sums the number of species in an area based on this crude distribution information.

“At the very least, we’d expect to see a sensitivity analysis of some kind to test for this, or some validation in the region of interest. For example, the study estimates the bat fauna of southern China and neighbouring countries increased by a whopping 40+ species in around 120 years. To put that into perspective that would mean the number of bat species in Myanmar doubled in little over a century! Simply looking back at old species accounts and ecological studies from the region shows this simply did not happen.

“Overall I’m not convinced the analysis is robust enough to draw the conclusions asserted. Spatial models like this can tell us a lot about the effects of climate change, and are on the whole very useful. But since this study makes quite strong claims about the emergence of Covid-19 which could have quite serious implications for bat conservation efforts, I believe the evidence really should be backed up further.”

‘Shifts in global bat diversity suggest a possible role of climate change in the emergence of SARS-CoV-1 and SARS-CoV-2’ by Robert M. Beyer et al. was published in Science of the Total Environment at 12 noon UK TIME on Friday 5 February 2021.

DOI: 10.1016/j.scitotenv.2021.145413

Declared interests

None received.