Shifts in global bat diversity suggest a possible role of climate change in the emergence of SARS-CoV-1 and SARS-CoV-2

Abstract

Bats are the likely zoonotic origin of several coronaviruses (CoVs) that infect humans, including SARS-CoV-1 and SARS-CoV-2, both of which have caused large-scale epidemics. The number of CoVs present in an area is strongly correlated with local bat species richness, which in turn is affected by climatic conditions that drive the geographical distributions of species. Here we show that the southern Chinese Yunnan province and neighbouring regions in Myanmar and Laos form a global hotspot of climate change-driven increase in bat richness. This region coincides with the likely spatial origin of bat-borne ancestors of SARS-CoV-1 and SARS-CoV-2. Accounting for an estimated increase in the order of 100 bat-borne CoVs across the region, climate change may have played a key role in the evolution or transmission of the two SARS CoVs.

Keywords: Coronavirus; Covid-19; Habitat shifts; Species distribution modelling; Vegetation modelling; Zoonoses.

Graphical abstract

Fig. 1

Estimated increase in the local number of bat species due to shifts in their geographical ranges driven by climate change between the 1901-1930 and 1990-2019 period. The zoomed-in area represents the likely spatial origin of the bat-borne ancestors of SARS-CoV-1 and 2.

Fig. 2

Environmental conditions and bat habitats in the likely spatial origin of the bat-borne ancestors of SARS-CoV-1 and 2. (a) Area of study, defined as a 500 km radius disk centred in the southern Yunnan province (101°E, 22°N). (b) Simulated relative distribution of natural biomes in the study area in the early 20th century (light blue bars) and at present (dark blue bars). Grey flows represent shifts in biomes between the time periods. (c) Habitat requirements of bat species whose extent of occurrence (see Methods) overlaps with the study area. Uncertainty bars represent upper and lower quartiles obtained from a bootstrap approach in which habitat requirements were determined for a set of 10⁴ random re-samples, with replacement, of these bat species. Proportions add up to more than 100% as species can have more than one suitable habitat type. (d)–(f) Boxplots representing the distribution of past and present monthly temperature, precipitation, and cloud cover normals across the study area. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)