The novel infectious disease – SARS-CoV-2 – is nature’s alert to humans. Existing research on the links between animal-borne diseases, human behavior and environmental change clearly demonstrate how humans and the environment are intrinsically connected, however currently in a profound imbalance. Already 70% of “new or emerging” diseases that infect humans originate in animals. In the wake of the SARS-CoV-2 outbreak and associated vast global health, security and economic damage, the environment-related underlying root causes of animal-borne diseases cannot be ignored any longer.
The prophecies of „climate wars”, projections of a European invasion of so-called “climate refugees” and assertion about how climate change is making our world more violent and less secure have caught scientific and public attention increasingly over the past years. However, a faster, greater and vastly unperceived risk of the environmental change represent animal-borne infectious diseases. The impact of the SARS-CoV-2 pandemic is global, seizing and transforming single lives, societies and economies. The German federal environment minister, Svenja Schulze, recently described the SARS-CoV-2 pandemic as a wake-up call for humanity. Truely, existing evidence on the relationship between the destruction of natural environment and biodiversity and new infectious human diseases such as Ebola, HIV, Dengue Fever and the different coronaviruses is staggering. If humanity destroys natural habitats like a tropical forest or people sell live or dead wild animals on so-called “wet markets” for human consumption, it creates the conditions for cross-species transmission of pathogens, hence new infectious diseases like SARS-CoV-2. In the wake of the SARS-CoV-2 outbreak, the environment-related root causes of animal-borne diseases cannot be ignored anymore. It confronts societies and leaders with challenges of civilization-historical significance, as it is the overall behavior of humanity which increasingly threatens to destabilize the earth’s key life-support systems. Therefore, a holistic approach is crucial to address the ongoing SARS-CoV-2 crisis. The decisions leaders will take, the lessons human civilization will learn, and the research scientists provide and initiate during the current pandemic are paramount. It may reduce the recurrence of animal-borne diseases, significantly alter the actions and behavior of human civilization in regard to the environment and foster long-term actions to address the environmental emergency.
SARS-CoV-2: a virus with striking features
The SARS-CoV-2 is the seventh coronavirus known to infect humans. Coronaviruses are a large family of viruses which can cause diseases ranging significantly in severity. The first known severe disease of its kind emerged in 2003 in China, called the Severe Acute Respiratory Syndrome (SARS) epidemic. The second severe outbreak of a disease caused by a coronavirus began in 2012 in Saudi Arabia with the Middle East Respiratory Syndrome (MERS). And most recently, on December 31, 2019, Chinese authorities alerted the World Health Organization of an outbreak of a novel strain of coronavirus, which was subsequently named SARS-CoV-2.
This virus which emerged in the city of Wuhan, China is the product of natural evolution, according to a vast number of scientific research, including the notable article published by an international group of biologists and virologists in the journal Nature Medicine. The SARS-CoV-2 genome demonstrates striking features for scientists: The mutations in the receptor-binding domain portion in the spike protein, the most variable part of the coronavirus genome, evolved to effectively target a molecular feature on the outside of human cells called ACE2, a receptor involved in regulating blood pressure. Moreover, the overall molecular structure of the virus’s backbone is highly distinct and mostly resembles related viruses found in bats and pangolins, thus underlining that the virus has natural origins.
Scientists highlight that there exist two possible scenarios for the natural evolution of SARS-CoV-2, which differ in the stage, when the zoonotic transfer occurred. Similar to other coronaviruses, the current virus could have evolved to its pathogenic state through natural selection in a non-human host and then jumped to humans. Researcher propose bats as non-human host and assume that an intermediate host was likely involved between bats and humans. The other scenario, considered less likely by experts, suggests that a non-pathogenic coronavirus entered humans and evolved to its current pathogenic state within the human population. For this scenario experts suggest that a pangolin possibly transmitted the coronavirus to a human, either directly or through an intermediary host such as cats or ferrets. While it remains challenging to affirm which scenario holds true, the distinction matters for the prevention of future animal-borne infectious diseases. Experts explain that if the first scenario applies and SARS-CoV-2 entered humans in its current pathogenic form, it raises the probability of re-emergence events. In fact, the disease-causing strain of the virus could still be circulating in the animal population and might once again jump into humans. However, if the adaptive process occurred in humans and even if repeated zoonotic transfer occurs, the emergence of properties similar to SARS-CoV-2 is unlikely.
Human’s behavior provokes animal-borne diseases
Evidence on the natural origin of SARS-CoV-2 pandemic does not mean that humans are innocent. It’s quite the contrary. This global health crisis, most likely unleashed by an animal virus jumping to a human, demonstrates better than any tsunami, drought or flood how the environment and human behavior are interconnected.
The social impact of the environment has been a subject of academic study for many centuries. In the 1970s many scientists already warned about the overuse and destruction of environmental resources and mentioned an accelerated human alienation from nature. For instance, E.F. Schumacher in 1977 observed that many humans did no longer experience themselves as a part of nature, but rather as a force which is greedy and legitimized to dominate and conquer it. The catastrophic results – shrinking biodiversity, exploited natural habitats and resources, and climatic events – significantly influenced by human’s actions and behavior, led the European Parliament to declare a climate and environmental emergency in November 2019. A growing body of research analyzes human civilization’s dependence, interaction and major impact on the changing environment. In this context, increasing research explores the links between the emergence of infectious diseases and socio-economic, environmental and ecological factors. The results affirm that the health of humanity is intrinsically linked to the health of the environment. Evidence shows that the emergence and spread of Ebola, HIV, Dengue Fever and the coronaviruses are largely driven by changing ecological, epidemiological and socio-economic factors.
Experts highlight that notably it is humanity’s destruction of natural environment and biodiversity that paves the way for new infectious diseases like SARS-CoV-2. Driven by economic development, humans have been destroying the biodiversity through large scale deforestation, habitat degradation and fragmentation, agriculture intensification, an unsustainable food system, trade in species and plants, and anthropogenic climate change. The shrinking natural habitats of wildlife put humans in close contact with all sorts of animal species, which adds to the risks of diseases spilling over from animals to humans. Moreover, a globally mounting urban population demanding fresh meat also spurs the demand for wild animal meat which is found in tropical forests and wild landscapes. In some countries, wild animal meat has been upgraded from being rated indigenous people’s „bush tucker“ to being considered a luxury food. Such preferences spur the trade of many species: live or dead wild animals are sold for human consumption in wet markets. The wet market in Wuhan – presumably the starting point of SARS-CoV-2 – is known to offer wild animals such as live wolf pups, salamanders, crocodiles, scorpions, rats, squirrels, foxes, civets and turtles. In the same fashion, urban markets in other parts of the world, for instance in west and central Africa sell monkeys, bats, rats, larger mammals, insects and dozens of species of birds. Such markets and the connected plundering of tropical forests and other natural habitats create the conditions for cross-species transmission of pathogens, hence new infectious diseases like SARS-CoV-2.
The SARS-CoV-2 outbreak is a unique chance to restore the earth system
The „Anthropocene“, today’s era in which humanity has become a major factor in the development of the earth system, confronts societies and leaders with challenges of civilization-historical significance. The SARS-CoV-2 pandemic which is happening right now is a case in point. The (as yet) most severe and deadliest coronavirus is plunging the entire human civilization into an existential health, economic and social crisis. Animal-borne diseases are clearly on the rise and in the wake of this pandemic, the environment-related root-causes cannot be ignored any longer.
The German federal environment minister, Svenja Schulze, is urging people to rethink their lifestyle and relationship to the environment. This view is mirrored by the United Nations’ Executive Secretary of the Convention on Biological Diversity, who called for a global ban on wildlife markets to prevent future pandemics. However, Elizabeth Maruma Mrema also drives attention towards communities from low-income rural areas, particularly in Africa: Millions of people are dependent on wild animals to sustain their livelihoods. In other words, a strict ban of wildlife markets requires long-term solutions that consider local socio-economic and political factors, in order to avoid spillover effects such as illegal trade in wild animals, economic distress and social upheaval. A first step could include providing incentives and training to vendors in urban or wet markets on meat safety. Examples in Nigeria highlight that trained butchers significantly reduced the amount of unsafe meat that was sold. Moreover, global public information on animal-borne diseases can foster a long-term shift to alternative meats and food.
While governments’ priority is now to contain the impact of the SARS-CoV-2 pandemic, the momentum is also unique to raise awareness and take action on the root causes of animal-borne diseases. Governments need to recognize that wet markets, the destruction of biodiversity and habitats of wild species are a public health threat. Greater leadership and political will is required to foster global nature conservation. For instance, still little is done to address the high demand for soybeans and palm oil. It provokes logging, deforestation and industrialized plantations, causing the loss of habitats, species, and climate change. Moreover, hunting of species for meat and other products and harvesting of plants for medicinal purpose requires greater attention and regulations. The evident links between the SARS-CoV-2 pandemic, human behavior and its impact on environmental change should urge decision makers to invest in long-term solutions. This implies collaborating, empowering and seeking guidance through global initiatives such as the post-2020 biodiversity framework.
Moreover, each and every one is urged to rethink his or her lifestyle and behavior in relation to the environment. This includes evaluating the use of products, medicine and consumption of meat, as it impacts the production of soybean and palm oil, hunting and trade of wild animals. Ironically, the preventive measures, in particular the lockdown, to contain the spread of the coronavirus forced people to a standstill and entirely changed the daily lives. By effect, the environment already shows some transformations. Reduced shipping traffic has drawn dolphins among other animals to the ports of Italy and totally transformed Venice, as the city’s canals are suddenly clear, showing fish, crabs and multicolored plant-life. Moreover, the temporary reduction in nitrogen dioxide emissions – released by vehicles, power plants and industry facilities – have led to blue skies in cities where people have long become used to polluted air. These developments may stimulate people to assess their travel habits and associated environmental pollution.
Finally, academia has an important role to fulfill. Although it is probably impossible to prevent future animal-borne infectious diseases, their likelihood must be contained, and awareness developed. Research needs to be fostered on animal-borne diseases and on the increasingly visible inter-relations between the wellbeing of humans and the environment. To this end, interdisciplinary research is crucial to understand, balance and better govern human behavior impacting the environment.
The SARS-CoV-2 outbreak demonstrates to humanity what is at stake when the wide-ranging risks that the global environmental emergency represents are being ignored or underestimated. A holistic understanding of the SARS-CoV-2 pandemic and a joint effort by decision makers, civil society and academia will be crucial to finding sustainable solutions to preserve human health, security and prosperity in the future.
Christina Kohler
