Climate Change
Coronavirus: Just the Symptom of a Bigger Disease
Jerry Yang - Fall 2020
A couple years ago, screenwriter Aaron Sorkin (best known for his work on The Social Network) worked on a short HBO television series called The Newsroom featuring the daily goings-on of a media company. On one such episode, a deputy EPA administrator is interviewed and asked about the impact of climate change. In a resigned voice, he answers:
“Well, mass migrations, food and water shortages, spread of deadly disease, endless wildfires – way too many to keep under control, [and] storms that have the power to level cities”
At the time of writing, the National Weather Service has begun using Greek letters to name our hurricanes (we already used up the normal alphabet) and it isn’t an exaggeration to say that California is burning. This quote reads less like chicken-little and more like a filled out bingo card. One of these predictions, though, stands out from the others. Covid-19 may seem like a once in a generation freak occurrence but the extensive impacts of climate change have made pandemics not a matter of if but a matter of when. Natural events are more often than not related to one another – something to consider when fighting both this virus and the next one.
Understanding how the coronavirus pandemic began is a good place to start. Phylogenic analyses conclude that 2019-nCoV is most closely related to diseases found in bats and were likely transmitted from bat carriers to an unknown intermediate mammal host and then onto humans. The initial spreading event has by now been traced back to the Wuhan South China Seafood Market where a variety of wild animals are sold. The general scientific consensus is that the close proximity of a diverse array of wild animals to human beings was what allowed for the rise of the zoonotic 2019-nCoV disease1. This is far from the first time this has happened. The various lineages of HIV have each been traced back to independent cross-species transmission between humans and non-human primates in West Africa as a result of human bush hunters eating chimps infected with recombinant strains of SIV well suited to human infection2. The destruction of natural habitats via simultaneous climate change and deforestation is only accelerating this process. Unchecked development and urbanization pushes both wild animals and human beings closer increasing the chances for a zoonotic event to occur. At the same time, climate change disrupts the natural balance of things. Species are pushed out of their habitats and into contact with other species allowing for viruses to spread between the two and merge into deadlier diseases. Livelihoods are destabilized from droughts or natural disasters pushing people into hunting for wild game for their next meal3.
Comparison between cases per capita and PM2.5 pollution levels in the Netherlands – there’s a clear correlation between the two that goes beyond obvious population density factors
On a separate but related note, climate change and related human activities have not only given rise to the virus but have actively increased its severity. Since Covid-19 is a respiratory disease, it stands to reason that ambient air pollution would play a role in its lethality. There is little data to go off of right now, recent studies have found that air pollution tracks with Covid-19 deaths in the United States to an extremely large degree4. This is unfortunately yet another way in which the brunt of the pandemic is disproportionately felt by communities of color and those of lower socioeconomic status who tend to live in areas where environmental regulation has taken a back seat to industrial development. While this may be the most visible way in which pollution shapes Covid-19 lethality, it certainly isn’t the only way. Diseases are normally limited to spreading within areas of a certain climate. Malaria, for instance, can only survive in tropical places where mosquitos are able to lay eggs in pools of stagnant water. Shifting climates as a result of climate change, however, mean that climate-restricted diseases are able to infect places they otherwise wouldn’t have access to. In particular, the area in which people are at risk for malarial infection is already creeping northward. Even more worrisome is the idea that global warming may be spurring some pathogens to evolve higher heat resistance5. One of the first lines of defense the human immune system has is sparking a fever to increase body temperature and kill off infection. Widespread heat resistance renders such an approach unusable. Climate change is making us weaker in ways we never could have seen coming.
As a final point, let’s take a step away from the Covid-19 pandemic and travel to the northern latitudes. Rising global temperatures have resulted in the shrinking of glaciers and the melting of the arctic permafrost which, strangely enough, has major ramifications for the future of public health. 75 years ago, a reindeer was killed by anthrax bacteria in a remote corner of Russia and the corpse was frozen beneath the arctic permafrost. In 2016, a heat wave melted the ice allowing intact infections spores to spread and kicking off a major outbreak of anthrax. Other researchers have looked into the arctic ice and were shocked to see massive frozen ancient viruses with very little in common with their more modern cousins. Our immune systems having never been exposed to these pathogens, humanity would be caught even more off guard should a particularly deadly virus awake from its frozen slumber. These are not the plot of some movie but rather real problems created by climate change. Epidemiologists are already preparing for the day a corpse infected with smallpox is unfrozen, reanimating humanity’s most deadly rival.
Helped along by climate change and related human activities, the next waves of pandemics are coming. The Covid-19 pandemic is not an outlier but rather a sign of things yet to come. More than a million dead have been counted with more yet to come. Nonetheless, humanity now more than ever is aware and informed of the disastrous effects of disregarding the environment. Climate change is a speeding car heading off a cliff and humanity is asleep at the wheel. If there’s any silver lining to the harsh reality of this pandemic is that our alarm clock just went off.
References
[1] Akpan, N. (2020, March 09). New coronavirus can spread between humans-but it started in a wildlife market. Retrieved January 06, 2021, from National Geographic
[2] Peeters, M., Chaix, M., & Delaporte, E. (2008). Phylogénie des SIV et des VIH. Médecine/sciences, 24(6-7), 621-628. doi:10.1051/medsci/20082467621
[3] Bartlow, A. W., Manore, C., Xu, C., Kaufeld, K. A., Valle, S. D., Ziemann, A., . . . Fair, J. M. (2019). Forecasting Zoonotic Infectious Disease Response to Climate Change: Mosquito Vectors and a Changing Environment. Veterinary Sciences, 6(2), 40. doi:10.3390/vetsci6020040
[4] Cole, Matthew A.; Ozgen, Ceren; Strobl, Eric (2020) : Air Pollution Exposure and COVID-19, IZA Discussion Papers, No. 13367, Institute of Labor Economics (IZA), Bonn
[5] Smith, P. (2020, January 22). Johns Hopkins Researchers: Climate Change Threatens to Unlock New Microbes and Increase Heat-Related Illness and Death. Retrieved January 06, 2021, from Hopkins Medicine
[6] Doucleff, M. (2016, August 04). Anthrax Outbreak In Russia Thought To Be Result Of Thawing Permafrost. Retrieved January 06, 2021, from NPR
[7] Fox-Skelly, J. (2017, May 04). Earth - There are diseases hidden in ice, and they are waking up. Retrieved January 06, 2021, from The BBC