Over the years people have discovered links between climate change, urbanization, and the spread of zoonotic viruses like COVID-19. I’ve done a podcast for a previous course (BIOL2050) on this very topic and my group members and I found interesting correlations between the three which I will try to summarize here. To begin, for zoonotic viruses to spread from its natural host to us it needs to pass several “barriers” to infection. This process is called spillover and the barriers could be proximity to the animal, our own body’s defenses, exposure, etc. Climate change and urbanization have been lowering the difficulty of some of these barriers making it easier for spillover to happen. For our podcast, we talked at length about deforestation and the effects climate change has on vectors. As we continue to destroy the natural habitat of many animals, we start seeing animals migrate into urban areas. This could be pigeons, raccoons, species of monkeys, and bats, the virus’s natural host. In addition to this, with global temperatures rising due to climate change, vectors like the nefarious mosquito have increased their range into the higher latitudes where they would normally be held back by cold weather. Given that the mosquito is a popular vector for viruses, it is quite easy to see why this would be bad. All of this is just the surface though and the research goes much deeper. There is further reading in the works cited should you feel inclined to.
Works Cited
Plowright, R. K., Parrish, C. R., McCallum, H., Hudson, P. J., Ko, A. I., Graham, A. L., & Lloyd-Smith, J. O. (2017). Pathways to zoonotic spillover. Nature reviews. Microbiology, 15(8), 502–510. https://doi.org/10.1038/nrmicro.2017.45
Tollefson, J. (2020). Why deforestation and extinctions make pandemics more likely. Nature, [online] 584, pp.175–176. Available at: https://www.nature.com/articles/d41586-020-02341-1.
Harvey, J. A., Heinen, R., Gols, R., & Thakur, M. P. (2020). Climate change-mediated temperature extremes and insects: From outbreaks to breakdowns. Global Change Biology, 26(12), 6685–6701. https://doi.org/10.1111/gcb.15377
Applied Plant Ecology Winter 2020 