By Harriet Waymark
I would like to preface this article by acknowledging that the matters discussed within this article are based upon current scientific belief, and it is important to acknowledge that these facts may be subject to change as our understanding of the pandemic continues to grow. It should be noted that this article is intended to be an exploration of the origins of viruses such as COVID-19, and how future preventative measures can be implemented, and in reading this we need to remember the gravity of our current situation and acknowledge those affected and the lives lost to this pandemic. The reduction of deforestation is linked to reducing the risk of future outbreaks, and is not linked with eradicating the existing SARS-CoV-2 virus, and thus it is still very important to maintain hand hygiene, social distancing, and to abide by the advice from health professionals.
The COVID-19 pandemic has been a life-changing event on a global scale, and the consequences which have ensued it so far are devastating to our environments, our livelihoods, and most importantly to our health and wellbeing. In order to set the context for this discussion however, it is important that a few key terms are clarified.
The virus itself is not called ‘COVID-19’, but rather SARS-CoV-2, which is an abbreviation for Severe Acute Respiratory Syndrome Coronavirus 2. COVID-19 refers to the disease which is caused by the SARS-CoV-2 virus, which is an abbreviation for Coronavirus Disease (2019). It is important to distinguish between the virus, which is transmittable between both humans and animals, and the disease which gives rise to the symptoms associated with the COVID-19 pandemic (“Naming the coronavirus disease (COVID-19) and the virus that causes it”, 2020).
Zoonotic Diseases are those which are transmitted from animals to humans, and they make up over 60% of all existing diseases in humans, as well as 75% of all emerging infectious diseases (Poudel, 2020). Zoonotic viruses infect individuals most often when they handle live primates, bats and other wildlife, and the risk of contracting these diseases is higher as contact between humans and wildlife increases. The event of a virus jumping from an animal to a human is known as a “spillover event”.
‘Anthropogenic’ is a term which refers to invasive changes in nature made by mankind, and is often used to describe pollution. Within the context of this article, an ‘anthropogenic greenhouse gas’ refers only to the greenhouse gases produced through human activity (such as CO2 as a result of deforestation), rather than those which occur naturally in the environment.
This article also heavily refers to deforestation, which occurs when forests are converted into non-forests, and used for other purposes. However, this is a broad term, which for the purpose of this article encompasses all acts of disrupting forests and interacting with wildlife that would have otherwise remained isolated. As such, this term includes deforestation for the purposes of forestry and the lumber industry. This is not to say that the production of timber should be stopped, as it is essential in many ways to mankind, but rather that it should be limited, and done in areas in which contact with wildlife is minimal.
Deforestation and its effect on the spread of Zoonotic diseases
Did you know that around 30.6% of Earth’s global land surface is covered in forest? Deforestation accounted for around 17% of the global annual anthropogenic greenhouse gas emissions in 2010 alone (Gorte & Sheikh, 2010), and new research indicates that deforestation could also be linked increasing risk of transmission of Zoonotic Diseases. Such transmission has resulted in some of the worst outbreaks in history, including SARS, Ebola, HIV, and likely the new SARS-CoV-2 virus (Lambert, 2020).
Bats are thought to be the most likely reservoir for SARS-CoV-2, as it is 89% (Poudel, 2020) similar to another coronavirus which was derived from bats. This virus is known for causing the SARS pandemic in 2003, and the MERS-CoV outbreak in 2012. Bats are likely to be the source of emerging viruses for several main reasons, the foremost being that bats account for approximately a fifth of total mammal species in the world (Poudel, 2020). Their tendency to live in large colonies and their increased resistance to viruses makes them a prominent source of Zoonotic diseases.
But how do we explain the link between deforestation and Zoonotic transmission? As humans intrude further into the natural world, spillover events are becoming more common, which can be attributed to the fact that the risk of disease transmission relies primarily upon points of contact between humans and normally isolated wildlife species. Deforestation not only destroys the habitat of these wildlife species, but increases the length of the forest perimeter, as humans build roads and clear large areas of forest to make way for the production of timber and agriculture (Dobson et al., 2020). As the length of the forest edge increases due to the formation of agricultural sites and roads, as does the potential for contact between humans and wildlife that could carry a potentially Zoonotic disease. That is not to say that deforestation is the only cause of spillover events, as other potential sources include wildlife meat markets and illegal wildlife trafficking. However, deforestation is arguably the most common, and that which has the most tangible and achievable solution.
This means that reducing deforestation could be a method of preventing outbreaks and pandemics from occurring in the first place. It is argued by some biologists (Lambert, 2020) that being prepared for a pandemic should start with reducing the chances of these spillover events from happening, and reducing deforestation is one of the most cost-effective and efficient ways of doing so. However, whether or not these spillovers turn into pandemics depends on the qualities of the virus, and how humans respond to it (Lambert, 2020).
It is estimated that such interventions would cost roughly $1.5-9.5 billion USD each year (Dobson et al., 2020), based upon modelling from Brazil, who from 2005 to 2012, managed to reduce deforestation by 70%. This figure seems miniscule however, when in comparison with the current Global GDP drop in 2020 as a result of the pandemic, which currently sits at $5.6 trillion USD (Dobson et al., 2020).
When the two figures are compared, does it not seem entirely feasible to take such preventative measures, to ensure something like our current situation does not happen again? And in doing so, also minimise carbon emissions from tropical deforestation?
Dobson, A., Pimm, S., Hannah, L., Kaufman, L., Ahumada, J., & Ando, A. et al. (2020). Ecology and economics for pandemic prevention. Retrieved 22 August 2020, from https://science.sciencemag.org/content/369/6502/379.summary
Gorte, R., & Sheikh, P. (2010). Deforestation and Climate Change. Retrieved 22 August 2020, from http://forestindustries.eu/sites/default/files/userfiles/1file/R41144.pdf
Lambert, J. (2020). To prevent the next pandemic, we might need to cut down fewer trees. Retrieved 22 August 2020, from https://www.sciencenews.org/article/coronavirus-covid-19-pandemic-prevention-deforestation-trees
Naming the coronavirus disease (COVID-19) and the virus that causes it. (2020). Retrieved 22 August 2020, from https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it
Poudel, B. (2020). Ecological solutions to prevent future pandemics like COVID-19. Retrieved 22 August 2020, from https://www.nepjol.info/index.php/BANKO/article/view/29175