Covid-19 and the environment: causes and consequences

By Crowther Lab

In recent months, we’ve been asked many questions about Covid-19 and the environment. This Q&A is a brief review of what experts are saying – from science to policy. 

Several viruses exist in the coronavirus family. The respiratory disease called Covid-19 is caused by one of them: the SARS-CoV-2. Covid-19 is a zoonotic disease, meaning that the virus which is now spreading through human populations originated in another animal species. Coronaviruses are well-known to infect bats, and SARS-CoV-2 shows rather high similarity to viruses found in some bat populations, pointing to a likely bat origin (Latinne et al., 2020). What is still unclear is the chain of events that led to the transmission of SARS-CoV-2 to humans, and whether another species acted as an intermediate host. The first people to be infected seemed to have been in Wuhan, China. Many of them had had exposure to a market selling live animals, wild and farmed, but it is unknown whether the first human contamination did occur on the market (Huang et al., 2020).

While it will be difficult to ever fully pin-point the chain of events that led to the spillover of the Covid-19 disease to humans, scientists have long been warning about the risks of similar epidemics (e.g. Cheng et al., 2007). It is clear that environmental destruction, especially in the highly biodiverse tropics, is making the emergence of infectious diseases more likely (Morand et al., 2014). When humans disturb an ecosystem, it can modify the complex web of interactions between species, including interactions between pathogens and their hosts. Ecosystem degradation can also cause individuals of a species to migrate or forage closer to human settlements, carrying their pathogens with them. In this general context of disturbance, the more contact people or their farmed animals have with wildlife, the higher the chance of an eventual human contamination (Plowright et al., 2015). 

While images of animals reclaiming cities have been a joy to see, the benefits of reduced human activities will only be temporary and cannot be associated with lasting effects on biodiversity. Furthermore, wildlife could face an intensification of poaching, especially in the poorest countries. Lower surveillance of protected areas during the lockdown facilitates the operations of criminal organizations, although Covid-related travel restrictions also complicates international trafficking (Wildlife Justice Commission report, 2020). Additionally, the economic crisis could drive more people to small-scale poaching. Poaching can be a safety net for local populations during economic crises (Ballesteros & Rodríguez-Rodríguez, 2018), and poverty is a significant driver of illegal hunting and wildlife trade (Duffy et al., 2015). This is a good example to highlight how crucial the welfare of local communities is to any conservation goal.

Wildlife trade has been under scrutiny since the beginning of the Covid-19 outbreak, particularly around markets which deal in wild animal species. Early on, some international actors called for a general ban of wildlife markets. Others criticized this approach as simplistic and counter-productive. 

One of the arguments against a blanket ban is that it would likely drive the trade underground – an outcome made even more likely by the fact that large swaths of wildlife trade are already illegal, but nonetheless flourish in a multi-billion dollar criminal industry (‘t Sas-Rolfes et al., 2019). As researchers in ecology at the University of Oxford expressed in an opinion piece, “rushing to indiscriminately ban all wildlife trade in response to COVID-19 would not eradicate the risk of animal-to-human disease outbreaks. It could also have a severe impact on livelihoods and biodiversity.” Instead, they argue for “improved regulations that focus on health, [which] if implemented well, would avoid these effects while ensuring a low risk of future disease outbreaks.” 

Surely, stronger law enforcement against illegal trade and sanitary regulations of legal trade would be welcome improvements for biodiversity and human health.

As the world ground to a halt and over half of its population experienced a lockdown, pollution dropped. Globally, air quality went up, noise pollution went down and 2020 will see the biggest year-over-year greenhouse gas emissions drop ever recorded (between -5% and -10% compared to 2019, according to this Carbon Brief analysis). Some good news, among all the pain caused by the pandemic? Unfortunately, not really. This momentary drop in emissions has been purely incidental. It will be of little consequence in the long run if it is not followed by bold climate policies. In order to keep our planet’s warming within 1.5°C above pre-industrial temperatures, we need to decrease our emissions by nearly 8% per year, every year, starting now to reach carbon neutrality by 2050. Then, we must carry on by removing excess carbon that accumulated in the atmosphere (IPCC special report, 2018, UN Emissions Gap Report, 2019), a task for which the tools are yet far from ready (Fuss et al., 2018). However, we already know that among these tools, nature-based solutions like conservation and ecosystem restoration can play a key role while also benefitting biodiversity and human wellbeing (Griscom et al., 2017). Research from the Crowther lab has shown, for example, that there is significant potential to restore trees globally (Bastin et al., 2018).

Overall, the tremendous amount of work required to stabilize the climate may seem daunting. But in fact, the coronavirus crisis did deliver us one massive encouragement that this can be done. Why? Because this year, we saw substantial reductions in emissions, which were after all… a mere side-effect of temporary policies designed for a different goal entirely! This should make us confident that even larger reductions will be achieved, once ambitious and thoughtful public policies directly targeting emissions are finally put in place.

We are now at a turning point, where a lot will depend on the content of economic stimulus packages designed around the world to help economies recover. Will we choose the path to a sustainable future, or a return to a destructive business-as-usual?

In a guest article on IPBES (the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services),  four leading experts call for: “transformative change […]: fundamental, system-wide reorganization across technological, economic and social factors, including paradigms, goals and values, promoting social and environmental responsibilities across all sectors. As daunting and costly as this may sound – it pales in comparison to the price we are already paying.”

Some local governments are already taking bold, concrete steps. The city of Amsterdam for instance recently announced switching to a new economic model, called Doughnut Economics (Raworth, 2017), built explicitly around satisfying people’s needs within ecological boundaries. Meanwhile, experts in science, conservation and sustainability, including the Crowther Lab, have coalesced around strong principles to guide responsible action on nature-based solutions (Together With Nature). 

The tragedy of the COVID-19 pandemic and home confinement has heightened our collective awareness that our species, like any other, depends on the health of the ecosystems it lives in. Protecting our planet’s biodiversity and climate is ultimately protecting ourselves.