The Climate for Corona – our warming world is more vulnerable to pandemic

“If the impact of Covid19 is another step in the collapse of modern societies, then it is likely it will have been another climate-driven step in that collapse. Understanding that context is important for deeper learning about reducing future harm.”

Our world is changing because of a virus. As the human and economic impact unfold, how massive that change will become is still unclear. How we make sense of the cause and damage of the pandemic will be part of the lasting impact. The role of climate change in making humanity more vulnerable to coronaviruses should be taken into account as we reflect on those lessons. That is because there is scientific evidence that a warming world with unusual weather has driven new patterns of wildlife migration and undermined the health of certain wildlife populations, both of which lead to larger releases of novel coronaviruses that can infect us all.

It is already scientific consensus that a warming and changing climate is related to the spread of many pathogens, particularly due to the way some, like dengue, require warm weather (Lancet, 2020). Because I knew of that evidence and have been researching the ways that climate change is disrupting modern societies, I spent the past week looking into a possible climate connection to the current pandemic. As a generalist, I found the evidence for the influence of climate chaos on the likelihood of the appearance of the novel coronavirus Covid19 is circumstantial, but logically compelling. I am sharing that here immediately, as I believe it has implications for deeper learning about reducing future harm.

The coronaviruses that infect humans originally come from bats in the wild. The World Health Organisation (WHO, 2020) has confirmed that “the most likely ecological reservoirs for SARS-CoV-2 [covid19] are bats, but it is believed that the virus jumped the species barrier to humans from another intermediate animal host.” One way that climate change is increasing the likelihood of novel coronaviruses infecting us is by influencing the migratory patterns of those bats. Food is the driving force behind their migratory habits. Different bats eat different stuff, including fruit. Insects are a key food source, with a brown bat eating up to 500 mosquito-sized insects in an hour. In recent decades we have witnessed a collapse in insect populations around the world (Sánchez-Bayoa and Wyckhuys, 2019). Imagine if suddenly your local food source disappeared and you had wings? When bats shift to new locations, they mix with other populations of bats, which provide conditions for the emergence of new strains of virus. In addition, as bats appear in new locations, so they can come into contact with livestock and animals in wild food markets that they would not have done before. That provides conditions for the transfer of any viruses to those animals which then expose humans, as WHO (2020) has confirmed for Covid19. The same problems are affecting birds, with implications for other pathogens which affect humans. (In case you are interested, this paragraph is my summary of the relevance of four academic papers to the current issue of Covid19, by transferring their findings on a range of pathogens to what we know about coronaviruses (Estrada-Pena A, 2014; Evans et al, 2020; Peterson 2014; Purse et al. 2005)).

The widely reported collapse of insect numbers in recent years (Sánchez-Bayoa and Wyckhuys, 2019) is also part of another reason why climate change is making transmission of coronaviruses to other animals and then humans more possible. That reason is how a more unstable and less supportive ecosystem means less healthy populations of wild animals. One factor is simply the increasing variability of our weather, including temperature extremes, which has directly killed hundreds of thousands of bats in some locations, suggesting it has damaged the health of many of the rest. Then with far fewer insects to eat, bats need to work harder for their evening meals. They are less well nourished. Imagine if you were having to work extra hard, had less nourishing food and were exposed to wild changes in weather. You might come down with the flu. This is similar to what is happening to bats. The effect tends to be cumulative, because when bats succumb to one bug that means they are more likely to carry and shed larger amounts of coronavirus. For instance, climate changes have contributed to one fungal pathogen, white-nose syndrome (WNS), spreading to new regions. It has been found to reduce antiviral responses in bats, which means they shed more coronavirus (Davy et al. 2018). Not being an expert, nor wanting to do any up-close research for this blog, I don’t know if bats cough or sneeze, but with Covid19 their extra ‘shedding’ of the virus meant that ultimately humans became ill. “Thus, a pathogen predominantly infecting wildlife may additionally have cascading effects on spillover of other pathogens of significance for human health” wrote a large team of experts in a peer reviewed study earlier this year (Evans, et al 2020). They report that the same processes are occurring for other wildlife and pathogens, to “impact complete wildlife–livestock–human systems (e.g., avian influenza, tuberculosis)” (ibid, 2020).

Another way that climate change is increasing our risk of catching Covid19 is through the contribution of climate change to the destruction and degradation of habitats (Estrada-Pena et al. 2014). Prolonged changes in rainfall and temperatures, their increased variability and the shifting of seasons, aren’t sustainable for trees and other vegetation. That means the insects and animals living in those ecosystems are suffering. Biodiversity loss is already huge, as we are living through a mass wildlife extinction event (Diaz, et al 2019). The reduction of the total number of wild animals like birds and bats has implications for our exposure to disease. Why? Because these are ‘reservoir host populations’ for pathogens, and the fewer birds and bats there are, then pathogen concentration and mixing tends to be higher (for reasons of lowered genetic diversity and easier spread). That increases ‘spillover risk’ for zoonotic infectious diseases to humans (Evans, et al 2020).

Scientists are generally very reticent to step back from their specific research project, to join dots with other scientific findings and offer generalised reflections. That is partly because the culture of natural science is reductionist, seeking to establish or refute correlations as the basis for knowledge claims. That leaves people like me, a generalist who delves into different areas of science, to possibly trigger some scientists with attempts to join dots and offer bolder reflections. So, here goes…

There is sufficient evidence to conclude that Covid19 may be, in part, an impact of climate change. It may be yet another destructive climate event. As our climate changes, it stresses plants, insects and animals in the wild in multiple ways and so they become sick, infect each other, and therefore, as fellow animals on this planet, we can get sick. What we do to the web of life we do to ourselves, sometimes with a time lag to the rebound that extends for some years. But rebound there is and will be. Scientists might isolate one bit of this web of life to seek to establish relationships that are scientifically irrefutable, but in doing so could we be denying an obvious insight from a more holistic form of knowing? For instance, the importance of cumulative stressors. A few years ago, my Mum became severely ill. She went to the local doctors for help. They sent her home with pain killers and advice to rest. After another week of severe pain, she went back to the doctors. In the meeting, she asked if it might be Lyme Disease, though she had not been anywhere outside other than her back garden. They said that Lyme is so rare that it is impossible to get it in a garden in the UK, so sent her home with antivirals for a disease called shingles. After another week of severe pain, I demanded they test Mum for Lyme and give her the antibiotics as if she had it. Two weeks later she tested positive for Lyme. The spread of Lyme around the world is rapid, vast and directly related to climate change (Estrada-Pena, et al 2012). Doctors have not been learning fast enough about our changing world. It means my Mum, in her 70s, now has less physical strength in the face of flu and Covid19 risks. Some scientists are trying to better model cumulative impacts, but that can be as much from attachment to their method and profession than being particularly useful to our current predicament of interrelated cascading impacts on society. When I look at these topics, I don’t want to be like a seismologist who researches late into the night and not run out the library when it starts to shake. So let’s run with the implications of a view that climate change is making these pandemics more likely and see where we get to.

Implications of recognising a climate driver for some pandemics

The lasting impact of this pandemic on our societies is unclear at this time. It will be huge, horrible and potentially transformative. There will be many lessons to learn. If the impact of Covid19 is the latest step in the collapse of modern societies, then it would have been another climate-driven step in that collapse. Understanding that context is important for deeper learning about reducing future harm. I want to share some ideas that arise from recognising that new coronavirus outbreaks are partly related to unfolding climate chaos.

First, the current devastating pandemic is likely to happen again and again. Our climate is changing fast and damaging our living home. The implications of our new reality need exploring more frankly and creatively. The links between climate and corona provide an urgent and additional reason for acting effectively on slowing climate change, as well as changing societies to be more resilient to recurring disruptions from disease.

Second, research communities could shift the way they seek to assess and communicate societal risks and responses. “Many scientists and policymakers are embedded in institutions that are used to thinking and acting on isolated risks, one at a time,” said a report of 200 scientists on the risks of systemic global collapse (Future Earth, 2020). In complex systems we can’t claim to know the precise type and timing of impacts of our destabilising climate or the cascading societal effects. Therefore, debates about modelling and assessing risks can become a risk-increasing distraction from both bold carbon cuts and drawdown along with fair and deep adaptation. It is counterproductive for some scientists to condemn those people who are anticipating the worst-case scenarios and responding creatively and compassionately from that outlook. Instead, when the risks are so high, we need to analyse information with a precautionary outlook.

Third, slowing the pace of climate change and adapting to its impacts must become a central organising principle of society at all levels, from local to global through national and regional. The declarations of climate emergency must start meaning that, rather than being just an additional agenda item for busy executives and politicians.

Fourth, the impact of this pandemic is far greater on society than it needed to be, because of the nature of our economic system, which is dependent on financiers’ confidence of an increasing volume of trade, transactions and debts. In a world where disease and other disruptions are likely to increase, we need a different economic model which does not multiply and prolong the harm.

Fifth, risk from disease is multiplied in societies that do not look after each other or the vulnerable. Populations need to be healthy and cooperative, to avoid or overcome a pandemic. In many societies there are people who are poorly nourished, over-worked, stressed, having to work while sick, or so fed up with life they don’t self-isolate or physically distance when asked.

Sixth, recognising the climate-covid connection is an invitation to an awareness that humanity and nature are an interconnected whole, so that what we do to the whole we will do to ourselves. People are dying today because of centuries of an unrestrained culture of separation and domination.

These are for starters. There will be many other implications to explore, once more people join the conversation of the connection between climate change and disease, including Covid19. If you are interested in this topic, please consider engaging the research group in the Deep Adaptation Forum.

Is there something key to the climate-covid connection that I have missed out?​ It’s a hot and emerging topic with some research still forthcoming (Subudhi, 2020 forthcoming). If there is something that is important, please tweet me the relevant research (@jembendell). For instance, I have read that one possible way that climate change might be making some viruses more deadly is through raising the ambient temperature of the environment. Like humans, other mammals fight viruses by raising their body temperatures to kill the virus. The coronaviruses that are being shed by feverish bats and infecting humans have been surviving in temperatures that are at least 1.1 degrees higher than 170 years ago. Our fever response has been well calibrated over hundreds of thousands of years, on the back of tens of millions of years of mammalian evolution. Could this mean that the virus can withstand our fevers? I haven’t found peer-reviewed evidence for or against this theory yet, so if you know of such studies please share that with me via twitter. I would also welcome feedback on the issue of the impact of climate change on the transmission between humans. I have read theories and evidence for slower transmission in warm humid weather as well as the opposite argument. Again, if you have information from peer-reviewed studies, please share.

In conclusion, I want to express my gratitude to you for reading this blog. The arguments I make here are not ones that calm the mind. I have researched and written this piece during a constant sense of anxiety, as I worry about the safety of myself and my loved ones in the face of a great unknown. That unknown is neither the pandemic nor climate change. It is the unknown response of people, from our neighbours to politicians, if they try to deny their fear, escape from it or act from it. As we all become more anxious, let’s seek to help each other process our emotions so we might relate to each other in future with more open-hearted clear sightedness. Then we can act more from love than from either our fears or aversion to fear.

If, like me, you are experiencing difficult emotions in response to the current situation, please consider the free resources of the Deep Adaptation Forum. Individual therapeutic support is provided free by the Climate Psychology Alliance here


Davy C, et al. (2018) White-nose syndrome is associated with increased replication of a naturally persisting coronaviruses in bats. Sci Rep 8:15508

Díaz, Sandra; Settele, Josef; Brondízio, Eduardo et al (2019) “Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services [Advance copy]” IPBES. Available at

Estrada-Pena A, Ayllon N, De La Fuente J (2012) Impact of climate trends on tick-borne pathogen transmission. Front Physiol 3.

Estrada-Pena A, Ostfeld RS, Peterson AT, Poulin R, de la Fuente J (2014) Effects of environmental change on zoonotic disease risk: an ecological primer. Trends Parasitol 30:205–214.

Evans, T. S. et al (2020) Synergistic China–US Ecological Research is Essential for Global Emerging Infectious Disease Preparedness, One Health, Review.

Future Earth (2020) Our Future on Earth 2020.

Lancet (2019) Tracking the connections between public health and climate change, The Lancet Report 2019,

Peterson AT (2014) Mapping Disease Transmission Risk, Baltimore: Johns Hopkins University Press

Purse BV, et al. (2005) Climate change and the recent emergence of bluetongue in Europe. Nat Rev Microbiol 3:171–181.

Sánchez-Bayoa, F. and Kris A.G. Wyckhuys (2019) Worldwide decline of the entomofauna: A review of its drivers, Biological Conservation, Volume 232, April 2019, Pages 8-27. Accessible at

Subudhi, S. (2020, forthcoming) North American bats and their viruses: The effect of stressors on persistent infections and viral shedding,

WHO (2020) Coronavirus disease 2019 (COVID-19) Situation Report – 32, 21st February.

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