Climate and other Forms of Environmental Change: The Need for Health Workers to Think Systemically in a Shrinking World
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GRF One Health Summit 2012, Davos: Presentation by Dr. Colin Butler - Associate Professor - National Centre for Epidemiology and Population Health - Australian National University
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Climate and other Forms of Environmental Change: The Need for Health Workers to Think Systemically in a Shrinking World
- 1. Environmental change: the need for health workers to think systemically in a shrinking world “ One Health, One Planet, One Future ” Davos, CH February 19-22 , 2012 A/Prof Colin D Butler National Centre for Epidemiology and Population Health Mr. Kiyoshi Kimura with his record-breaking bluefin tuna price: $770,000 (2012) ($2,600/kg)
- 4. The parachute principle “ Demand will create a parachute”
- 5. Earth system observations Sea Level: 1993-2011 Rainfall intensity : 1900-2011 Land-ocean temperature: 1880-2011 Arctic ice: 1979-2012 Millions Km 2
- 6. 1998 2000 2004 2008 2011 Adapted from Murray & King, Nature . 2012; 481: 433-5. Apparent production cap 2005: Peak Oil Production (million barrels/day) Oil price (US$ per barrel)
- 7. Raw data: FAO Two food price spikes .. Is the era of cheap food over? NB – related to plant health oil 2 nd price spike: oil price + climate change?
- 9. Systems thinking & pandemic flu
- 10. Claude Bernard (1813-1878) milieu and microbe caption
- 12. Milieu and the Adapted from Oxford et al Lancet Inf Diseases 2002; 2:111-4
- 13. rapid public health response nutrition ok public health breakdown nutrition worse living conditions worse Could civilisation failure “breed” a megapandemic?
- 14. Added value of One Health approach Human health One health Food price Energy price Climate change Global nutrition shocks, social disturbances Health risk (including infection) deteriorating communication, cooperation, “one world, one health”, “think global act local” One health (broad vision)
Notes de l'éditeur
- I’d like to thank the organisers and sponsors My talk is called Environmental change: the need for health workers to think systemically in a shrinking world This is especially relevant to the “ One Planet, One Future” part of the title of this meeting. In the background here we can see a smiling Japanese gentleman. He has just paid $770,000 for a single fish. That is $2600 a kg. We know, from what I call brown economics, that this is a very good thing, because this high price will doubtless stimulate the production of even more valuable tuna
- I have been very pleased to hear several other speakers discuss systemic thinking, but for those of you who are new to the idea I thought I’d list a few keywords: Integrative Interactive, feedbacks, thresholds (emergence, phase changes, shocks A phase change is something that happens very often in Davos – each time a little ice melts or freezes. I’ll also talk a little about emerging diseases, and the concept of the disease milieu, or “terrain”
- This slide is a bit of a history lesson. Some time ago, I won’t say just when, the theme for World Health Day was “Our planet; our health; Think globally, act locally”. “Think globally, act locally” is often attributed to the microbiologist Rene Dubos, who as some of you may know, had a young wife who died of TB, in the 1940s. I don’t know if she tried a sanatorium for treatment, but Dubos went on to write the White Plague. Later in his life Dubos became a kind of planetary health ecologist, and he co-wrote a book called “Only One Earth”. Dubos was central to what historians might one day call Rio minus 20. This book was commissioned by the UN secretary general in preparation for the Stockholm Conference on the Human Environment. Now, we are almost up to Rio plus 20, and the Lancet recently published this editorial. Global health in 2012: development to sustainability. The historians among you will also recall that Dr Brundtland chaired the World Commission on Environment and Development which led to the report called “Our Common Future” in 1987, which popularised the term “sustainable development”. Of course, Dr Brundtland went on to become the director general of WHO, and you might think it was she who promoted the theme for World Health Day, but in fact it was her predecessor, Dr NAKAJIMA, in 1990. Now, I think, the term “sustainability” is a little overworked, I prefer to think of “survival”. But I know if I use that term I risk alienating some of you, as it seems too alarmist. I think talking about the future is like finding the right dose of a vaccine. The purpose of the vaccine is to prepare us for the future. But if we are too alarmist then we can become infected with pessimism and despair. But if we are too reassuring, too anodyne, then the vaccine is worse than a placebo, because it induces false complacency (1988-97)
- Even before that World Health Day I heard a joke. Two people have fallen from a very tall building. One is an ecologist and the other is an economist. The ecologist is terrified, but the economist is supremely calm. Don’t worry, he says, “d emand will create a parachute” The person who told us that joke was vilified by many people; some of you will have heard of him. His name is Paul Ehrlich. If we go back to the vaccine analogy, it is very clear that Ehrlich alienated many people because his message was too painful to hear. I personally think, on my good days, that a parachute is possible. But we are not going to use that parachute unless we can see the ground, and unless we can anticipate the consequences of hitting the ground, and I think far too, many people, including policy makers, politicians and what we could call the consuming class of about 1 billion people are in denial. They cannot see the ground, though by now, perhaps a few hundred million can, and they are calling very hard for the ripcord to be pulled.
- These are 4 earth system indicators. I could have chosen many more. Those of you who are or who have been clinicians will know that the bedside chart is very important, or perhaps the chart in the kennel or veterinary hospital. When I used to go on ward rounds it would often be the first thing I’d look at it. Here, we can see the temperature of the land and ocean is rising, there is growing evidence that rainfall is becoming more erratic, with both more intense rainfall and also more intense drought; with more variability, making it harder for farmers. This also has implications for human health, especially those living in low lying areas near rivers, in poor housing. The third indicator here is sea level rise. The good thing about this is that the rate of sea level rise is not noticeably increasing, at least over the last 20 years. However that is likely to change later this century. The final sign here is the extent of Arctic ice. The blue line is very recent data, from just a few weeks ago, and it show the coverage of Arctic ice since November. Basically it is tracking the dotted line which is the earlier record low, from 2006-07. The grey band is the average between 1979-2000.
- Here is another indicator, of a precious earthly fluid, called oil. Essentially, we are bleeding our home planet of stored fossil fuel. This chart was published last month in Nature. One of the authors is Sir David King, the former chief scientist of the UK. It also shows the abysmal failure of brown economic theory. The red line show the price of oil in US$ since 1998, and here it is smoothed out. The blue line shows the production of oil. As we saw with the tuna, as the price rises, the production will be stimulated, and for a while, until about 2005, it was. Since then there has been a plateau, even though the price has continued to rise. Fatah Birol, chief economist of the International Energy Agency agrees with Sir David King.
- Here, I have a slide which is about plants. It is also another Earth System indicator, not based on modeling or speculation, but in fact more disturbing evidence of trouble. The rising food price in 2008, at a time when oil reached almost $150 a barrel has been widely discussed. In fact, at the World Health Assembly meeting that year, the rising cost of food was identified by WHO as one of the three major emerging global health issues, the others being climate change and pandemic flu. But in December 2010 the global food price exceeded the 2008 record, at a time when the cost of oil was well under US$100/barrel. There has as yet been little analysis of this, but I think the cause is a combination of extreme weather events, biofuels and high energy costs. And I think the extreme weather events, such as the heatwave in Russia and Ukraine of 2010 and the floods in Pakistan in the same year are related to climate change. I am a contributing author to the IPCC chapter on health, and my particular topic is nutrition. But there is no time here to go into details.
- So, in summary, we have a civilisation at risk. We have emerging scarcity of raw materials, not just oil and energy; but also phosphate – essential for fertiliser - and rare earths – essential for the New Industrial Revolution that optimists look forward to. We have an archaic economic system, which is better suited for a world that is much earlier on the curve, before the planet got so full. This system denies limits to growth, and we need urgently need green economics .. but this has been pointed out by visionaries from John Stuart Mill to EF Schumacher for a long time, with little result, as yet. Finally, we have immense inequality, and that breed civil stress, terrorism, fascism and war
- Now I want to turn to Systems thinking & pandemic flu I want to start with a confession – that is that I have never published a paper about flu, and I’ve never even spoken at a conference on it. Also, it’s not mentioned in my abstract. So I feel a bit like a little boy in a Danish fairy tale, after seeing the Emperor.
- A person who interests me a great deal is the French physician, Claude Bernard, a predecessor of Pasteur. Bernard is credited with developing the principle of bodily homoestasis. It is said, though there is some controversy about this, that near the end of his life Lous Pasteur said something like: Bernard was right – it is the milieu, or terrain, not the microbe that really matters. But I want to suggest that both matter. Now in the top box we have a flock of wild birds. These birds are mobile, of varying age groups, and probably of varying immune status. Sometimes they exist in large numbers, but they probably rarely if ever experience the density and proximity of the birds on the right. Persistence of Highly Pathogenic Avian Influenza Viruses in Natural Ecosystems Camille Lebarbenchon,1 Chris J. Feare, François Renaud, Frédéric Thomas, and Michel Gauthier-Clerc Terrain as well as the microbe (Bernard) Evolutionary theory suggests the pathogenic “lethality/longevity” tradeoff is altered by opportunity; eg HPAI/LPAI oscillation Persistence of Highly Pathogenic Avian Influenza Viruses in Natural Ecosystems Camille Lebarbenchon,1 Chris J. Feare, François Renaud, Frédéric Thomas, and Michel Gauthier-Clerc Understanding of ecologic factors favoring emergence and maintenance of highly pathogenic avian infl uenza (HPAI) viruses is limited. Although low pathogenic avian infl uenza viruses persist and evolve in wild populations, HPAI viruses evolve in domestic birds and cause economically serious epizootics that only occasionally infect wild populations. We propose that evolutionary ecology considerations can explain this apparent paradox. Host structure and transmission possibilities differ considerably between wild and domestic birds and are likely to be major determinants of virulence. Because viral fi tness is highly dependent on host survival and dispersal in nature, virulent forms are unlikely to persist in wild populations if they kill hosts quickly or affect predation risk or migratory performance. Interhost transmission in water has evolved in low pathogenic infl uenza viruses in wild waterfowl populations. However, oropharyngeal shedding and transmission by aerosols appear more effi cient for HPAI viruses among domestic birds.
- Basically, because of lack of time, I am not going to try to explain in any detail the evolutionary factors which I think make HPAI more likely to evolve in the indoor bird flock than the outdoor one, but essentially I think it is related to the trade-off hypothesis, developed by the evolutionary biologist Paul Ewald and others. To simplify, this theory is that pathogens, in order to maximise the longevity of their species, generally trade rapid lethality for a more benign state, which gives the pathogen a greater chance to reproduce. If a pathogen kills all of its hosts very quickly then it will run our of hosts. This is perhaps best documented for syphilis, which when it came to the immunologically naive European population was apparently very florid. Within a few human generations it had become much more quiescent. It still killed people, but it took much longer. Also, its symptoms became more subtle. Essentially, I am suggesting that the industrial chicken farm creates the conditions for the H5N1 – and perhaps other flu viruses and other pathogens, to evolve in ways that are very contagious to birds and also that there is less evolutionary penalty from having a high and rapid lethality. Persistence of Highly Pathogenic Avian Influenza Viruses in Natural Ecosystems Camille Lebarbenchon,1 Chris J. Feare, François Renaud, Frédéric Thomas, and Michel Gauthier-Clerc Terrain as well as the microbe (Bernard) Evolutionary theory suggests the pathogenic “lethality/longevity” tradeoff is altered by opportunity; eg HPAI/LPAI oscillation ------------------- Understanding of ecologic factors favoring emergence and maintenance of highly pathogenic avian infl uenza (HPAI) viruses is limited. Although low pathogenic avian infl uenza viruses persist and evolve in wild populations, HPAI viruses evolve in domestic birds and cause economically serious epizootics that only occasionally infect wild populations. We propose that evolutionary ecology considerations can explain this apparent paradox. Host structure and transmission possibilities differ considerably between wild and domestic birds and are likely to be major determinants of virulence. Because viral fitness is highly dependent on host survival and dispersal in nature, virulent forms are unlikely to persist in wild populations if they kill hosts quickly or affect predation risk or migratory performance. Interhost transmission in water has evolved in low pathogenic infl uenza viruses in wild waterfowl populations. However, oropharyngeal shedding and transmission by aerosols appear more effi cient for HPAI viruses among domestic birds.
- Of course, in recent years, there has been enormous concern that H5N1 will become a devastating human pandemic. As far as I can see this apprehension is not just of an “ordinary” pandemics such as those which have probably occurred every few decades for several centuries, most recently in 1968, but something far more deadly, perhaps even rivalling the 1918-19 pandemic most commonly called the “Spanish” flu (I apologise to the Spaniards in the room). It is fairly well known, especially to this audience, that that pandemic killed about 2.5% of the global human population. Although many of these deaths were probably from secondary bacterial pneumonia, and the number could have been reduced had antibiotics been available, there is widespread agreement that this was very severe Here, I declare my heresy, and I request your indulgence. I don’t think that is likely, because I don’t think we currently have the right milieu to “breed” a strain of influenza that will be sufficiently devastating to humans. However I think that such conditions did exist towards the end of WWI on the Western Front, and it is conceivable they could re-emerge. The virus almost certainly did not originate at the Western Front, but may have arrived in about 1916, and then gradually increased its human killing power over the next two years, before being seeded throughout the world, including in densely crowded troop ships that perhaps allowed the virus to maintain high lethality and transmissibility. There were also opportunities for viral mixing on the front with various bird species and pigs. But the most fundamental difference was the high and densely populated number of troops, some with co-existent infections, some with exposure to poison gas. In summary, I think the conditions on the front were rather similar to an intensive chicken farm. You can see that I am not the first to think like this, indeed I am indebted to John Oxford and his group for seeding this idea in me, in their paper, from 2002. I also attribute Paul Ewald as an influence. Even if we are all wrong I think the possibility warrants far more attention than it so far been received. Basically, because of lack of time, I am not going to try to explain in any detail the evolutionary factors which I think make HPAI more likely to evolve in the indoor bird flock than the outdoor one, but essentially I think it is related to the trade-off hypothesis, developed by the evolutionary biologist Paul Ewald and others. To simplify, this theory is that pathogens, in order to maximise the longevity of their species, generally trade rapid lethality for a more benign state, which gives the pathogen a greater chance to reproduce. If a pathogen kills all of its hosts very quickly then it will run our of hosts. This is perhaps best documented for syphilis, which when it came to the immunologically naive European population was apparently very florid. Within a few human generations it had become much more quiescent. It still killed people, but it took much longer. Also, its symptoms became more subtle. Essentially, I am suggesting that the industrial chicken farm creates the conditions for the H5N1 – and perhaps other flu viruses and other pathogens, to evolve in ways that are very contagious to birds and also that there is less evolutionary penalty from having a high and rapid lethality. Soldiers from Fort Riley , Kansas ill with Spanish influenza at a hospital ward at Camp Funston in 1918, where the worldwide pandemic is hypothesized by some to have begun. 2: 111-4
- However, I do think these conditions could emerge. We know, especially in parts of Asia and Africa that there are very densely crowded human populations, and already many are undernourished, especially in India. I very much hope I am wrong, but I worry that if we keep our present trajectory, with high birth rates, resilient poverty, crowding then the interaction with climate and other forms of adverse global environmental change could breed one or more megapandemics. But that will be far from our only problem. Of course, in recent years, there has been enormous concern that H5N1 will become a devastating human pandemic. Not just on the scale of “ordinary” pandemics which have probably occurred every few decades for several centuries, but in fact something more like Spanish flu (apologies to the Spaniards in the room) which perhaps killed 2.5% of the global population. I don’t think that is likely, because I don’t think we currently have the milieu to “breed” a strain of influenza that will be devastating to humans. However such conditions may have existed towards the end of WWI on the Western Front. The virus almost certainly did not originate there, but may have arrived in about 1916, and then gradually increased its human killing power. It was then seeded throughout the world, including in densely crowded troop ships. There were also opportunities for viral mixing on the front, with various bird species, also pigs. But most fundamentally the high number of troops, some with co-existent infections, some with exposure to poison gas. Acted as a way like a human industrial farm.
- This is my last slide: how does this work add to the value of One Health. I have argued that we need to think more broadly, more ecologically. We need to think outside the box. I have also given reasons for thinking that eco-social population health determinants will deteriorate globally, unless we can take collective action to change our current trends – unless we can open the parachute. I have not talked about solutions, as there is lack of time, but there clearly are some, including this One Health movement. I think that a new global consciousness is evolving, but it needs to be accelerated. Together, this understanding can merge into a broad vision of one health. The last thing I want to say is that there is also room for reductionist thinking. I think there are large cognitive barriers to thinking wholistically, though I also think systems thinking is not so foreign to many people working in human and animal health, because we understand animal bodies as a system. We need to broaden our thinking of the indivual animal or even herd, flock or population, to see how all of life is embedded in a wider system. Thank you.