Does environmental damage increase the risk of pandemics?

It has become painfully obvious that humanity has not conquered the threat of infectious diseases. Future health risks may interact with other risks of environmental degradation – including from pollution, biodiversity loss and climate change – to threaten food security and potential global catastrophe.

The current pandemic has precipitated an unprecedented shock to the global economy – but is there a link between humanity’s environmental impact and the risk of future pandemics?

Since the emergence of Covid-19, researchers and various international bodies have speculated about the link between the spread of coronaviruses and the encroachment of people into wild habitats, or the degradation of ecosystems. The United Nations Development Programme and the World Wildlife Foundation call for greater protection of biodiversity as a safeguard against the spread of infectious diseases, as do Dasgupta and Anderson (2020) and Prince Charles.

The study of defined insurable risk is well established in economics. Here, instead, we assess existential risks due to environmental damage using insights from two other strands of research: planetary boundaries (PBs), to which ecologists and earth system analysts are key contributors; and global catastrophic risks (GCRs), where futurists are the leading contributors.

What are planetary boundaries?

Planetary boundaries (PBs) are one of the ways of thinking about the risk of further pandemics. PBs describe the estimated levels of environmental change that minimise risks to the survival of humanity and explicitly take account of humanity’s role as a force driving change in earth systems (Rockstrom et al, 2009; Steffen et al, 2018). PBs set boundaries that represent quantifiable markers of ‘safe operating spaces’ for humanity that, once crossed, could have irreversible consequences for the survival of humanity. Climate change and biosphere integrity are classified as ‘core’ boundaries that interact with other boundaries (Steffen et al, 2015; Steffen et al, 2018).

Rockstrom et al (2009) identify ten PBs:

Table showing Rockstrom et al's ten planetary boundaries

Studies have explored how PBs interact with sustainable development (for example, Raworth, 2017; Griggs et al, 2013; Nilsson et al, 2016). The importance of ‘safe operating spaces’ for our health is emphasised recently by Dasgupta (2020).

The PBs approach relates to the discussion of weak and strong sustainability in the economics of sustainable development (Barbier, 2019). This research stresses the link between intergenerational wellbeing and natural capital (for example, Arrow et al, 2012; McLaughlin et al, 2014; Polasky et al, 2019). In this context, natural capital is broadly defined as all ‘gifts of nature’ or natural assets – which includes stocks of renewable and non-renewable resources, such as forests and minerals, ecosystems that generate a flow of services over time, and the global climate system (Hanley et al, 2015).

The main distinction between weak and strong sustainability is that weak assumes that all forms of capital (physical, human and natural) are substitutable, whereas strong assumes that there are critical thresholds (that is, planetary boundaries) in natural capital and warns about limits to human exploitation.

What are global catastrophic risks?

Global catastrophic risks (GCRs) are another paradigm focusing on existential risks due to environmental harm (for example, see the work of Martin Rees 2003, 2018 and his team at the Centre for the Study of Existential Risk). The range of possible scenarios is great and ascertaining the likelihood of such events is difficult given that there are no observational data on human extinction on which to draw (Tonn and Stiefel, 2013). In effect, this school focuses on low probability but high impact events.

Bostrom and Cirkovic (2008) identify three categories of GCRs:

Risks from nature (super volcanoes, comets and asteroids, supernovae and solar flares)
Risks from unintended consequences of human activity (climate change, pandemics, artificial intelligence and social collapse)
Risks from hostile acts (nuclear war, bioterrorism and nanotechnology).

There is no absolute demarcation line between risks relevant to the PBs paradigm and GCRs. Recent research has attempted to address this overlap by suggesting the hallmark of a GCR event is that it significantly disrupts a critical system (Avin et al, 2018), which may or may not be part of a PB.

Within economics, several studies have attempted to quantify the threat posed by GCRs. Most notable here are Weitzman (2009) and Ng (2016), who illustrate the implications of low probability but high impact catastrophes, and explore how these should be weighted in decision-making frameworks. One important low probability but high impact event is a pandemic, which until recently hardly figured on the radar of many economists and policy-makers. Galizzi et al (2020) provide a good discussion of various risks.

Related question: Risk in the time of Covid-19: what do we know and not know?

How are planetary boundaries and global catastrophic risks related?

Baum and Handoh (2014) call for an integration of PBs and GCRs paradigms. The main distinction between PBs and GCRs are the spread and predictability of the risks concerned:

PB risks are gradual and predictable.
GCRs are sudden and relatively unpredictable.

Here we illustrate the connection between PBs and GCRs using the example of climate change and health risks. The link between climate change and the incidence of vector-borne disease (vectors are living animals that transmit infectious pathogens from animals to humans or between humans) such as malaria and tick-borne diseases is well-established (WHO, 2003; ICS, 2017; Campbell-Lendrum, 2015; Bouchard et al, 2019). Also, pathogens are known to adapt to increases in temperature, creating the drug-resistant fungal species that have emerged in the past decade (Casadevall et al, 2019).

Baum and Handoh (2014) note that humans could be resilient to crossing a PB, but if there is an interaction with socio-economic institutions (for example, a supply chain failure in relation to life-saving drugs) this might create a disastrous outcome for humanity.

The conventional argument is that public health interventions can mitigate the risk of pandemics occurring (for example, Kilbourne 2008), but this assumes that there is a functioning and focused public health administration free of political manipulation, where evidence is evaluated cogently, and personnel and materials are available, including key medicines, to allow for appropriate interventions to be carried out.

Is there a link between planetary boundaries, food security and coronaviruses?

How the world will feed itself in future has been a longstanding issue (see the Stern Review, 2006; and Sachs, 2015). Food security refers to the stable access, availability and utilisation of safe and nutritious food; the Food and Agriculture Organization of the United Nations (UN) annually reports on food insecurity. Of all economic sectors, agriculture is the most at risk to the vagaries of climate, and food security is threatened directly by climate change (IPCC 2018), in part because increased agricultural activity impinges on other PBs, including land use change (deforestation) and biodiversity loss (de Castro Solar et al, 2016).

Animals provide a sizeable share of the food supply of the planet. But animal populations can also experience catastrophic levels of disease that can affect supply chains and human health in a number of direct and indirect ways (Vilanova et al, 2019). For example, African swine fever is a highly infectious viral disease that mainly affects domesticated pigs and is spread from wild boars, first discovered in Africa in the early 1900s and spread beyond Africa in the early 2000s to the trans-Caucasus region of Russia and Eastern Europe (see Sánches-Cordón et al, 2018) and on to China (Zhou et al, 2019).

Coronaviruses are a family of viruses that mutate and infect other species – ‘cross-species transmission’ – and are quite common (Broadbent, 2020). Livestock are a potential source of communicable disease, but more alarming is that in the event of a health shock to livestock, this may force people to scavenge for food from untried meat sources, risking exposure to new viruses.

Evidence that wild food is frequently an alternative to farmed meat comes from bushmeat consumption and trade where poverty is a strong driver in demand (for example, Lindsey et al, 2013, Fischer et al, 2014, Moro et al, 2013). Bushmeat has been linked to epidemics, such as Ebola, which resulted in bushmeat bans during epidemics, although these belated bans had the unintended consequences of reducing public confidence in public health responses (Bonwitt et al, 2018).

Although at this time, there is no direct evidence that climate change has affected the transmission of coronaviruses, it has indirect effects on the movement of animals, which creates opportunities for pathogens to cross species. Deforestation is another potential indirect transmission path, as land use change brings wild animals into contact with domesticated animals.

The important point here is that these dynamics increase the risk of transmission of zoonotic diseases, diseases caused by viruses, bacteria or fungi that spread between animals and people. Examples of zoonotic diseases are the 2009 H1N1 influenza pandemic that originated in swine and infected both pigs and humans (Scotch et al, 2011). The World Health Organization’s 2015 list of top emerging diseases were all zoonotic diseases (Garrod, 2020) and early genome analysis of Covid-19 indicates zoonotic origin, as viruses in bats and Malaysian pangolin had a 99% similarity to SARS-CoV-2 (Hassanin, 2020)

Interaction of planet boundaries and global catastrophic risks

Here we highlight the problems caused by interactions of risky and near-catastrophic events that can occur and create risks at several levels. One of the most obvious and well known interactions relates to food and health.

China experienced a devastating epidemic of African swine fever, first reported in August 2018, that decimated an estimated 40% of the swine population, increased meat prices, and left more than 8% of the Chinese population malnourished (Beck and Tobin, 2020). Many Chinese farmers had switched to poultry and canines as protein sources in the wake of the epidemic. An early study of the outbreak in China shows how cases were located in provinces neighbouring Hubei – the epicentre of the Covid-19 pandemic (Wang et al, 2018) – and African swine fever continues to be a lingering threat in China (Shike, 2020).

Such food insecurity by itself can creates vulnerabilities to climatic events (Hu et al, 2017), natural disasters in the broadest sense, with the lurking danger that agricultural mismanagement will create hazards to human health.

These problems are not reserved to Asia. Another example in recent memory comes from the Bovine Spongiform Encephalopathy (BSE) outbreak in the UK in the 1980s and 1990s, which resulted in an EU ban on UK beef exports that was lifted as late as 2006, as well as 178 UK deaths from BSE’s human variant, Creutzfeld Jacobs Disease (Beck et al, 2005).

One of the most frightening prospects concerns a situation where catastrophic or gradual climatic events trigger a major pandemic, which in turn affects food supplies and the supply of other health relevant goods such as pharmaceuticals. Shortages of key pharmaceuticals have already occurred and the underlying complex global manufacturing supply chain has shown itself vulnerable to natural disasters. A prime example of this occurred when Hurricane Maria made landfall in Puerto Rico in September 2017 and destroyed much of the injectable production capacity in the United States, causing a major shortage of intravenous saline (Slacks et al, 2018).

Similar problems are now occurring on the back of the Covid-19 epidemic, where supply disruptions of active pharmaceutical ingredients, the production of which is concentrated in China and India is already causing major disruptions (Choo and Rajkumar, 2020).

Potential global worst case scenarios thus arise where existing networks of interacting insecurities in the areas of politics, economics, climate, food, biological safety and food supply – which already imperil human health and survival – are aggravated by the occurrence of one or several major natural, technical or hybrid disasters. These are scenarios that development practitioners already view with the greatest of concern (for example, Ngumbi, 2020 and UN, 2020).

Figure showing connections between different types of insecurity.

Conclusion

Verner et al (2016) note that research on the health risks and health implications of climate change is underdeveloped. Interactions between health systems and climatic shocks can leave us vulnerable. Many health impacts can be controlled through adopting proactive measures (Wu et al, 2016) and there are reasons to be optimistic as scientific knowledge advances (Kingsland, 2020). But these measures require timely interventions and capable national and multinational institutional frameworks.

As we have seen with Covid-19, new diseases create immediate challenges to medical systems and the public, for which we need to be prepared while we await the development of vaccines, which can take over a year. Increasing microbial resistance to antibiotics aside, it has now become painfully obvious that humanity has not conquered the threat of infectious diseases, and a lot more attention will need to be paid to this issue in the future.

Ultimately, this brings us back to the importance of maintaining the integrity of our natural capital as crucial means for maintaining the welfare of humanity today and in the future (Guerry et al, 2015).

A key message for future policy-makers and students alike is to think broadly about how to address the fundamental causes of a pandemic (degradation of our natural capital) as well as treating the symptoms unleashed by a pandemic.

Where can I find out more?

Risk: A study of its origins, history and politics: This book by Matthias Beck and Beth Kewell is a historical analysis of how our understanding of risk interacts with politics.

The Dasgupta Review: The interim report of the independent review on the economics of biodiversity led by Professor Sir Partha Dasgupta.

Coronaviruses – a brief history: An expert summary of coronaviruses

Bushmeat could cause the next global pandemic: An article on the health risks from bushmeat.

How a warming climate could affect the spread of diseases similar to Covid-19: An article on the link between climate change and risks of the spread of future infectious diseases.

How might climate change affect the spread of viruses?: Scientific assessment of how climate change will affect the spread of viruses.

Why are economists letting down the world on climate change? A call to arms for economists to be more engaged with climate change as a major public policy issue.

Genuine savings and sustainability: An expert review of research on the economics of sustainable development published in the Journal of Economic Surveys.

A pandemic of hunger: An opinion piece calling attention to the interaction between the pandemic and food insecurity.

Pandemics result from destruction of nature, say UN and WHO: An article summarising recent calls for legislation to support green recovery.