Climate change, health and categories of effects

 

I wrote this for another paper, currently under review. However, it was cut, due to lack of space. Eventually, I hope to weave this material into another article, and also into the forthcoming second edition of my edited book “Climate Change and Global Health”. This also builds on a blog I posted in 2015 called “Climate change and heath: primary, secondary and tertiary effects.

1. Primary and secondary effects

The first categorizations of the health effects of climate change and health appeared in the early 1990s. Principally these identified two broad kinds of effect, most often called “direct” (such as from heatwaves, reduced cold or physical trauma from a more powerful storm) and “indirect”, such as from ecological shifts leading to an altered distribution of vectors (such as mosquitoes) or of food sources (see tables 1,2).

Table 1. There are many classifications of the health effects of climate change. This is one suggestion for the most obvious, least contentious effects. All of these effects interact with other factors, such as governance, infrastructure, technology and economic and other capabilities.

Heat stress, heat stroke (including occupational); heat stress resulting in impairment of chronic diseases (e.g. multiple sclerosis, cardiac or renal failure) or death, possible fetal abnormalities; in some cases improved health from reduced cold

Physical and or psychological harm and trauma from an intensified storm, flood, fire or other extreme event, such as drought or a storm surge

Long-lasting psychosocial effects from exposure to a climate change aggravated extreme event including post traumatic stress disorder, depression, loss of place and “solastalgia” ------------------------------------------------------------------------------------------------------------------

The burden of disease of “direct” (“primary”) effects can be severe, as with the tens of thousands of excess deaths attributed to heatwaves in France in 2003 [1] and Russia in 2010 [2]. The burden from excessive heat is likely to substantially increase, especially if the Paris commitments are not met. Regions in which hundreds of millions now live are forecast as at risk of large-scale human abandonment late this century, including the North China plain and parts of the Middle East [3,4]. Looking further ahead, if urgent action to slow climate change by accelerating the energy transition is further delayed, substantial regions of the globe could experience wet bulb temperatures of 35 degrees or more, calling into question the habitability of even more some regions [5].

The burden of disease of the secondary effects (see table 2) of climate change, particularly of infectious diseases such as malaria, has long been forecast as significant [6]. However, although it is likely that climate change has increased cases of malaria in some settings, especially in highlands [7] the overall global burden of malaria has declined substantially in recent decades, mostly because of the increased use of insecticide impregnated bednets and more funding [8]. Note however, that such progress has recently stalled, especially in parts of sub-Saharan Africa [9]. I am unaware of any recent attempts to estimate the global burden of disease of malaria or other infectious diseases attributable in part to climate change, although a recent editorial in Geospatial Health provides an excellent summary of the key issues [10].

Table 2. Climate change has many less direct effects, which can be called “secondary”. Few if any of these are controversial. These effects also interact with other factors, such as ecological change, governance, trade, infrastructure, technology and economic and other capabilities.

Vector borne diseases (eg malaria, dengue fever, yellow fever, chikungunya, Zika), non-vector born zoonotic disease (e.g. schistosomiasis, Ebola, HIV/AIDS); other infectious diseases (e.g. gastro-enteritis, soil transmitted helminthiases)

Impaired food or water safety (microbial or toxic), reduced food diversity; reduced micronutrient concentrations in crops (due to higher CO2 levels)

Allergies, including thunderstorm asthma; asthma

Cardio-respiratory-neurological effects, such as from worsened tropospheric air pollution, or from climate change aggravated fires

Reduced food sovereignty, reduced micronutrient intake, but without the threat of starvation

Impact on other chronic diseases, such as cardiac failure, diabetes ------------------------------------------------------------------------------------------------------------------

2. Tertiary effects

Two papers, each published in December 1993, identified a third category of health effects, which the authors called “tertiary” [11,12] (see table 3). One paper stated “indirect effects are secondary, such as changes in vector-borne diseases or crop production, and tertiary, such as the social and economic impacts of environmental refugees and conflict over fresh water supplies”. The other paper additionally noted that: “There is a considerable literature on the effects of climate on disease which focuses principally on the primary effects of temperature on health. In relation to global climate change, however, it is likely that the secondary and tertiary impacts will outweigh the importance of the primary effects” [12].

This idea of a third major category of health effect has not yet been widely accepted. A 1996 book on climate change and health mentioned “more diffuse” effects including conflict and population displacement, but grouped these with indirect effects, rather than as a separate category [13]. An assessment for the U.S. National Assessment on climate change and health, published in 2000, identified five categories of health outcomes [14]. These were related to temperature, to extreme weather events (storms, tornadoes, hurricanes, and precipitation extremes); to air-pollution, and to two categories of infectious diseases. In turn these were each divided into two kinds; related to water and food, and vectors and rodents. This report did not discuss migration, social disruption, or conflict, perhaps because its scope was restricted to that of the U.S.

As mentioned above, it has long been understood that climate change can influence important social consequences (with health effects) such as population displacement, conflict and malnutrition. Malnutrition refers both to undernutrition (e.g. stunting, wasting and at its most extreme, death) and, also, to obesity and other problems associated with excessive calorie intake, sometimes (also) associated with micronutrient deficiency. Two of these effects (malnutrition – albeit probably meaning undernutrition – and conflict) were mentioned in the the first article I know of about climate change and health, published in the peer reviewed literature, a 1989 editorial in the Lancet [15], while Alexander Leaf, also in 1989, discussed both population displacement and the possibility of increased hunger [16].

These effects may also be considered tertiary not only because they are the least direct, but also because of their capacity to harm health is at such a large scale. For example, the conflict in Syria, which several experts think was contributed to by the most severe drought in its instrumental record [17] has displaced millions, had profound geopolitical effects in Europe, and killed hundreds of thousands of people, including children. The health effects upon survivors, both physical and mental, both in Syria and for those displaced, are undoubtedly immense [18]. Of course, climate change is not solely responsible for this catastrophe, and its exact contribution is disputed [19,20]. The total health impact of the Syrian conflict is likely to far exceed that of the 2003 European heatwave, particularly as much of the health harm to Syrians is to infants, children and young adults, whereas deaths from heatwaves typically result in a comparatively low per person loss of disability adjusted life years, as it is primarily the already frail and elderly who die [21]. The morbidity and mortality from the Syrian conflict due to anthropogenic climate change is likely to already be very significant, even using a highly conservative causal attribution.

It has also been suggested that the 2018 crisis of refugees seeking entry to the U.S. from Central America has been exacerbated by drought (interacting with social and other environmental factors including inequality and high population growth rates), which in turn probably has a climate change contribution [22]. There are many other examples, already, in which climate change has been argued to contribute to conflict, undernutrition, migration and other forms of population displacement [23]. For example, Hurricane Maria, which directly killed 64 people in Puerto Rico, contributed to at least 4,000 additional deaths in the following four months, due in part to the interaction of the storm with an already vulnerable social and physical system, with large-scale and long-lasting damage to electricity infrastructure [24]. It also led to migration to the U.S., particularly by younger people and those more economically able. 

Table 3. This lists the most obvious “tertiary” consequences of climate change that will have significant health effects. As with the primary and secondary effects, these interact with governance, infrastructure, technology and economic and other determinants.

Increased hunger, starvation or famine (exceeding a reduction in nutrient variety)

Mass migration or population displacement, including from climate change aggravated events such as famine, drought, sea level rise, violence and intolerable heat

Large scale conflict (leading to physical and mental trauma, death and morbidity, including from damaged health systems)

Significant social and economic disruption, impairing health and/or health systems ------------------------------------------------------------------------------------------------------------------

In 2005 a paper written by health workers, published outside the health literature, argued that the global health effects of eco-climatic change could be classed into four categories; three equivalent to primary, secondary and tertiary (though the paper did not use these terms), and a fourth, which it called “systems failure”, a euphemism for global civilization collapse [25]. This paper also predicted that the loss in disability adjusted years for the third and fourth categories would exceed the first two.

A figure in a chapter on climate change and health published in 2007 in the third report of the Intergovernmental Panel on Climate Change (IPCC) also recognized three broad categories of health effects. It called these “direct”, “indirect” and via “social and economic disruption” [26]. However, the text did not discuss the third category.

In 2010 the terms (and closely corresponding concepts) of primary, secondary and tertiary were revived, in a paper, and later, an edited book that failed to identify the earlier use of these terms [27,28]. Also in 2010, a report for several U.S. government agencies [29] classified the human health consequences of climate change into eleven kinds. These were listed alphabetically as asthma, allergies and airway diseases; cancer; cardiovascular disease and stroke; alterations in normal development; heat-related morbidity and mortality; mental health and stress disorders; neurological diseases and disorders; nutrition and food-borne illness; vector-borne and zoonotic disease; waterborne disease and weather-related morbidity and mortality. The report discussed displaced people (such as due to Hurricane Katrina) as a cross-cutting issue. It also recognized the possibility of conflict, war (outside the U.S.) and extensive undernutrition, both domestically and globally.

The health chapter in the most recent IPCC report [30] also referred to three kinds of health effects of global warming. It called these “direct” (mainly from “heat, drought, and heavy rain”), “mediated through natural systems” (e.g. “disease vectors, water-borne diseases, and air pollution”) and “heavily mediated by human systems” (e.g. “occupational impacts, undernutrition, and mental stress”). The first two categories in this classification correspond with primary and secondary, but in the third category only large-scale undernutrition would be classed as a tertiary effect, as defined above.

In 2015 another major Lancet report was released [31]. It proposed that impacts can be “direct” (e.g. “heatwaves and extreme weather events such as a storm, forest fire, flood, or drought”) or “indirectly mediated through the effects of climate change on ecosystems economies, and social structure” (e.g. “agricultural losses and changing patterns of disease” and “migration and conflict”). It thus grouped “tertiary” effects with “secondary”, though it used neither term. A figure in that paper which outlined the main direct and indirect effects focused solely on what this essay suggests are more parsimoniously termed as primary and secondary effects.

Conclusion

Apprehension of what I prefer to call the "tertiary" health effects of climate change has always been the primary motivator for my writing and researching on climate change (since my first letter, published in the Medical Journal of Australia, in 1991) [32]. I have argued above that these potential aspects were apparent in 1989, when articles first appeared mentioning all major "tertiary" components. I have also shown that the term "tertiary" was introduced in two papers published in 1993, already a quarter of a century ago. 

Although there is increased recognition of these risks, the vast majority of the climate change and health literature continues to focus on issues such as heat, infectious diseases and allergies. Important as these issues are - and they are certainly are valid - I believe that their future burden of disease is likely to be dwarfed by that of the tertiary issues; conflict, population displacement and famine. 

In 2014, in a chapter in my edited book called "Mental health, cognition and the challenge of climate change [33] I published a version of the following figure. In the next issue of the book the figure may be adapted, so that the label for the x axis (the horizontal axis) reads 2030. In 2014 I suggested that it might take until 2050 for the high burden of disease of the tertiary effects to be accepted, but that book was drafted before as much was reported about climate change and conflict in Syria, although an early paper was published in 2014 [34}.

I fear, given the events of 2018 - the fires, the floods, the hurricanes and typhoons, and the ongoing population displacement, as well as a gradually increasing acceptance of the role climate change plays in conflict - that the time in which the overwhelming risk of the tertiary health effects of climate will be widely understood may well be before 2050.  On the other hand, the vast majority of articles in the climate and health field continue to completely ignore its existential risk [35].

The proportional burden of disease of primary, secondary and tertiary effects (averaged over the 21st century) and the approximate time when these concepts and their relative burdens are accepted.

A powerful opposing force, however, is not just denial, nor just the political factors that seek to repress any whiff of legal liability, and hence minimize the risk of future reparations. One way to suppress such exploration is to refuse to fund research into the possible links. I think another reason has evolutionary roots. People like to portray themselves as “good", even moral. Even the Nazis probably did .. so while on one hand populations fully support policies that contribute to unspeakable misery, on the other hand they deny the reality of the links between their behaviour and the more displaced effects, especially if they are harmful. If the causes can be ascribed elsewhere ("local politics in Syria, not environment") then we can feel better about ourselves. A good example is that most Australians support offshore camps for asylum seekers, claiming this is “humane” because “it saves lives at sea”.  However, my view is that the causation of this and other tertiary effects is multi-factorial. Developed countries have largely contributed to climate change, but there are also many local factors that have contributed to the war, famine, displacement, and the risks people take which see some drown at sea.  

 

However, the  pendulum on the causes of the tertiary effects of climate change is currently too remote from recognition of the role that high-income countries have played in these catastrophes [36}, already and in future. And some people increasingly understand that climate change and other forms of planetary overload [37] pose profound risks to human well-being in high-income settings, such as 15 year old Swedish climate activist Greta Thunberg, who also keenly appreciates the equity dimension (see figure).

A tweet from 15 year old Greta Thurnberg, posted October 7, 2018

References

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2.         Shaposhnikov, D.; Revich, B.; Bellander,T.; Bedada, G.B.; Bottai, M.; Kharkova, T.; et al. Mortality related to air pollution with the Moscow heatwave and wildfire of 2010. Epidemiology 25, 359-364 (2014).

3.         Kang, S.; Eltahir, E.A.B. North China plain threatened by deadly heatwaves due to climate change and irrigation. Nature Communications (2018).

4.         Pal, J.S.; Eltahir, E.A.B. Future temperature in southwest asia projected to exceed a threshold for human adaptability. Nature Climate Change 6, 197–200 (2016).

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9. Alonso, P., and A.M. Noor. The global fight against malaria is at crossroads. The Lancet 390:10112 (2017).

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13. McMichael, A.J.; Haines, A.; Slooff, R.; Kovats, S. Climate change and human health. World Health Organization: Geneva (1996).

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16. Leaf, A. Potential health effects of global climatic and environmental changes.  The New England Journal of Medicine 321 (23):1577-1583 (1989).

17. Kelley, C. P., Mohtadi, S., Cane, M.A., Seager, R. and Kushnir, Y. Climate change in the Fertile Crescent and implications of the recent Syrian drought. Proceedings of the National Academy of Sciences (USA) 112 (11):3241-3246. doi: 10.1073/pnas.1421533112 (2015).

18. Anonymous. Syria: A health crisis too great to ignore. The Lancet 388, 2 (2016).

19.       Selby, J.; Dahi, O.S.; Fröhlich, C.; Hulme, M. Climate change and the Syrian civil war revisited. Political Geography (2017).

20. Ide, T. Climate war in the Middle East? Drought, the Syrian Civil War and the state of climate-conflict research. Current Climate Change Reports:1-8; doi: 10.1007/s40641-018-0115-0. doi: 10.1007/s40641-018-0115-0 (2018).

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22.       United Nations World Food Programme. Food security and emigration. https://docs.wfp.org/api/documents/WFP-0000019629/download (2017).

23.       Schleussner, C.-F.; Donges, J.F.; Donner, R.V.; Schellnhuber, H.J. Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries. Proceedings of the National Academy of Sciences, 113, 9216-9221 (2016).

24.       Kishore, N.; Marqués, D.; Mahmud, A.; Kiang, M.V.; Rodriguez, I.; Fuller, A.; Ebner, P.; Sorensen, C.; Racy, F.; Lemery, J., et al. Mortality in Puerto Rico after hurricane Maria. New England Journal of Medicine, doi: 10.1056/NEJMsa1803972 (2018).

25.       Butler, C.D.; Corvalan, C.F.; Koren, H.S. Human health, well-being and global ecological scenarios. Ecosystems, 8, 153-162 (2005).

26.       Confalonieri, U.; Menne, B.; Akhtar, R.; Ebi, K.L.; Hauengue, M.; Kovats, R.S.; Revich, B.; Woodward, A.; Abeku, T.; Alam, M., et al. Human health. In Climate change 2007: Impacts, adaptation and vulnerability. Contribution of working group II to the fourth assessment report of the intergovernmental panel on climate change, Parry, M.L.; Canziani, O.F.; Palutikof, J.P.; Linden, P.J.v.d.; Hanson, C.E., Eds. Cambridge University Press: Cambridge, UK,, 2007; pp 391-431 (2007).

27.       Butler, C.D.; Harley, D. The climate crisis, global health, and the medical response Postgraduate Medical Journal 86, 230-234 (2010).

28.       Butler, C.D. Climate change and global health. CABI: Wallingford UK, Boston, US; p xxiv + 303 (2014); paperback issue published 2016.

29.       Portier, C.J.; Thigpen Tart, K.; Carter, S.R.; Dilworth, C.H.; Grambsch, A.E.; Gohlke, J.; Hess, J.; Howard, S.N.; Luber, G.; Lutz, J.T., et al. A human health perspective on climate change: A report outlining the research needs on the human health effects of climate change. Research triangle park, NC: Environmental Health Perspectives / National Institute of Environmental Health Sciences. doi:10.1289/ehp.1002272 available: www.niehs.nih.gov/climatereport (2010).

30.       Smith, K.; Woodward, A.; Campbell-Lendrum, D.; Chadee, D.; Honda, Y.; Liu, Q.; Olwoch, J.; Revich, B.; Sauerborn, R.; Aranda, C., et al. Human health: Impacts, adaptation, and co-benefits. In Climate change 2014: Impacts, adaptation and vulnerability, contribution of working group ii to the fifth assessment report of the intergovernmental panel on climate change, Field, C.B.; Barros, V.; Dokken, D.J., Eds. Cambridge University Press: Cambridge and New York; pp 709-754 (2014).

31.       Watts, N.; Adger, W.N.; Agnolucci, P.; Blackstock, J.; Byass, P.; Cai, W.; Chaytor, S.; Colbourn, T.; Collins, M.; Cooper, A., et al. Health and climate change: Policy responses to protect public health. The Lancet 386, 1861–1914 (2015).

32.      Butler, C.D. Global warming, ecological destruction and human health. Medical Journal of Australia 155:351 (1991)

32.      Butler, C.D., Bowles, D.C; McIver, L., and Page, L. Mental health, cognition and the challenge of climate change. In Climate Change and Global Health, edited by C.D. Butler, 251-259. Wallingford, UK: CABI. (2014).

34.       Gleick, P.H. Water, drought, climate change, and conflict in Syria. Weather, Climate, and Society 6 (3):331-340. doi: 10.1175/wcas-d-13-00059.1 (2014).

35.      Butler, C. D. Climate change, health and existential risks to civilization: a comprehensive review (1989-2013).  International Journal of Environmental Research and Public Health (under review). 

36.      Butler, C.D. "Regional overload” as an indicator of profound risk: a plea for the public health community to awaken. In Medicines for the Anthropocene: Health on a Finite Planet, edited by S. Quilley and K. Zywert. Toronto, Canada, University of Toronto Press, 2019 (in press).  

37.     Butler, C.D. Planetary overload, limits to growth and health.  Current Environmental Health Reports 3 (4):360-369 (2016)

Climate change and health: Tony McMichael and an "index of existential risk"

It's another average day for me, except that that, were Tony McMichael still alive, it would be his 76th birthday. Tony was one of the the first leading figures in public health to recognize the risk to human health from climate change.

The trough in the annual cycle of carbon dioxide levels is now over 405 ppm (parts per million). The Federal President of the Young Liberals has just pronounced that Australia should not take any leadership role in tackling climate change. Even more worryingly, he has suggested that the billion or so people without electricity should be illuminated by coal burning. (But Indian President Modi does not agree (see endnote - PPS)). The lead author of a new article on ancient climate (about 50 million years ago) has just been quoted as saying that “Some climate models suggest that the tropics just became a dead zone with temperatures over 50 degrees Celsius (122 degrees Fahrenheit) like in Africa and South America.. but we have no data so we don’t know.” At the time he was discussing (called the early Paleogene), carbon dioxide levels may have been 1000 ppm.

I have an article under review which reports an "index of existential risk" for climate change and health, identified in the climate and health literature. I looked at 2,146 articles, editorials and news items, published in the first 25 years of this literature (1989-2013 inclusive). Each paper was given a score between 1 and 3, depending on the degree to which they recognized that climate change may pose an "existential risk" to civilization, and thus health. The average score of these papers was 1.37. 

The average score of Tony's 74 papers was 1.99 (see figure). I mentioned this last week, when I had the chance to talk at the Public Health Association of Australia's 2018 conference, after I received the 2018 award for public health, ecology and environment, named after Tony McMichael. The slides for my talk ("From life support to regional overload") are here. 

The press release for this award stated that I see civilization at risk, not life, if we continue the current trajectory of fossil fuel burning (and other approaches to planetary boundaries). This is not because it may become so warm that there may again be crocodiles and palm trees in the Arctic Circle, but because the chaos that will be inflicted upon human society through many processes associated with "regional overload" (of which unfavourable climate  change is but one) are likely to outweigh human coping capacity. Here are three candidate contributors, in no order: (1) drought, heat and rising food prices triggering more political instability; (2) sea level rise on the US East Coast leading to a massive loss in property values and thus worsening a financial crisis; (3) a mass human flight from north east China later this century, due to intolerable heat and humidity. 

Even now, solutions might be found. The technology for electricity and elective transport is rapidly advancing. California seeks to be 100% carbon free by 2045. Education reduces fertility (reduced fertility in many settings is important, not to slow climate change, but to reduce climate change related catastrophes in the global South). But these solutions need high level recognition by our political leaders, and that needs the global middle class to understand that rapid transition, towards sustainability, is both urgent and attainable.   

PS Later this month I am teaching, in Finland, in a short course on climate change and health, based on my edited book. (I have just agreed to edit a second edition but it will take some time.)

PPS Prime Minister Modi is reported as saying that:

1. He saw the 121 country International Solar Alliance as the future OPEC for meeting energy needs of the world

2. India would add as much as 50 GW (gigawatts) of non-hydro renewable energy to its existing 72 GW and is on track to reach its target of 75 GW of clean energy by 2022

3. That India’s solar energy increased by nine times in the last four years

4. That in the next four years as many as 28 lakh (2.8 million) solar pumps would be installed which would help avoid 10 GW generation capacity. 

5. 31 crore (310 million) LED bulbs were distributed

50GW is a lot - according to the 2018 Clean Energy Report less than 6 GW of large scale renewable energy projects were under construction or expected to start in 2018, in Australia.

Tony McMichael's 74 papers (1989-2013 inclusive) on climate change and health, scored by their recognition of existential risk.

“Regional overload” as an indicator of profound risk: a plea for the public health community to awaken

Comments welcome. First draft of an abstract for a chapter in a forthcoming book to which I have been asked to contribute called: "Health in the Anthropocene: Living Well on on a Finite Planet" My slides are here, for a talk at the University of Waterloo, Canada on April 5, 2018.

Public health is the field of medicine charged with protecting human well-being, via the identification of health risks and the development and implementation of effective strategies to lower such dangers. Public health workers have a long history of promoting new paradigms and tackling vested interests, often with great difficulty and against immense opposition. Their campaigns often take decades to be successful, even at a regional scale.

Today, the greatest threat to global public health is barely visible within public health circles, although, like blind men palpating an elephant, some of its many manifestations are recognized. These identified protuberances have several names. Ecological public health, climate change and health, and even planetary health have arisen, in recent decades, as sub-disciplines of public health. The risk of nuclear war to health has seen the awarding of two Nobel Peace prizes to health-related lobby groups. Tropical medicine has evolved to international health and global health.

Yet, none of these emerging sub-disciplines or fields, as yet, fully integrate the health risks arising from what McMichael called “planetary overload”. Central to this (Malthusian) conceptualization is the risk of large-scale conflict, famine and infectious diseases, acting, increasingly, in combination, in ways that reduce human well-being, as a consequence of linked “eco-social” phenomena. 

Crucially, ecological and environmental contributors to these crises must be recognized not just as living elements of the biosphere, such as crops, coral reefs and forests, but inert resources, particularly of fossil fuels and the rare elements needed to drive the accelerating energy transition. Although the health community is belatedly awakening to the public health harm that climate change constitutes, there is scarcely any recognition, within public health, that the growing scarcity of these inert resources risks the triggering of social consequences with profound adverse health consequences, many of which are already apparent, in examples of what Butler has termed “regional overload”.

There is a growing number of recent examples of this; from Syria to Yemen, South Sudan, north-east Nigeria and Myanmar. However, very little analysis exists, within public health, of the shared causal pathways which underpin these localized public health catastrophes. 

There are many reason for this scarcity of analysis. One is the bias, within most public health fields, to problems in high-income settings. Publications on (for example) public health in South Sudan are rare, and data-rich papers are almost non-existent, due to the difficulties of safely obtaining such data. This leads to a reinforcing cycle, a positive feedback loop, where there is little market or appetite for analysis, and where such papers, if submitted are unlikely to be accepted due to their likely deficiencies. 

Another important impediment is of disciplinary boundaries and suspicion of the “academic other”. These factors contribute to the failure of academic institutions and health funders, who are overwhelmingly embedded in a milieu of neoliberal signals and incentives, to recognize the need for a new paradigm to emerge, if humanity is to thrive in this and coming centuries.

***
PS regional overload is long-standing, and is different to what really concerns me; which is regional overload in the context of tightening global limits to growth. That really warrants a new term, or phrase, but it is too premature to attempt that.

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Limits to Growth, Planetary Boundaries and Planetary Health: history and future

This is a background paper for a workshop held at the University of Sydney on December 13, 2017, in conjunction with the launch of a platform about planetary health. My slides are here.

Planetary health has been described as the amalgamation of the health of human civilisation and its underpinning natural systems. There is wide agreement among natural scientists that the current modification of nature is unprecedented, judged by biodiversity depletion, easily accessible fossil fuel, nitrogen in soil and water, and the level of atmospheric greenhouse gases, indicators which, are key “planetary boundaries”.(1) At the same time the number and average life expectancy of humans (and the numbers of the tiny range of animal and plants which humans eat) has never been higher.

Civilisation, in fact, may be likened to an enormous nature-transforming machine, with a seemingly unstoppable trajectory. But is there a limit? If so is it near?

Almost 2,000 years ago Tertullian lamented how the Mediterranean world was becoming full.(2) 219 years ago, another Christian, Malthus, published his analysis of the “principle of population”,(3) arguing, essentially, that humans would fill whatever ecological niche was available to them, limited by their capacity to grow food. Malthus informed Darwin and Wallace’s theory of evolution,(4) but revealed ignorance of at least one exception to his principle, that of Indigenous Australians, who appear, on the whole, at that time, to have lived within their “eco-social” limits for millennia, thanks mainly to the preventive check of child spacing rather than the “malignant” checks of periodic famine, epidemic, or genocide.(5)

In the 1960s, when global human population growth peaked as a percentage, before the success of the Green Revolution (which greatly increased crop yields due to new crop strains and the use of fossil fuel-dependent fertilisers, pesticides and irrigation) was fully appreciated, concern grew that parts of the world were destined for what some called “Malthusian” traps, as regional human carrying capacity(6) was exceeded, including in parts of sub-Saharan Africa.(7) About then, the Club of Rome commissioned a computerised study to try to dynamically and quantitatively model the human future until 2100.

This study, called the Limits to Growth, became an unexpected best seller, but was intensely criticised by an emerging generation of “neoliberal” economists. The Limits to Growth found that the supply of natural resources, obviously essential for well-being, would become scarce by 2100 under all but the most optimistic scenario, in which human population growth was slowed. Critics dismissed this core assumption, arguing that even if scarcity did occur, market forces would evolve substitutes.

By 2000, the Limits to Growth was almost forgotten, considered by many experts to have been discredited as civilisation still persisted at that time. Among these critics was the 2003 Global Environmental Outlook 3, the flagship report of the United Nations Environment Programme, which incorrectly claimed that Limits to Growth predicted world collapse by 2000.(8)

In contrast, The Limits to Growth concluded that collapse, were it to occur, would be well after 2000. In the “standard run” (see figure) collapse commences by 2050, though this may be postponed by more “enlightened” policies, even if introduced late. Under all of its range of assumptions the study concluded that global food supplies would keep pace with population growth for at least several decades into the new millennium.(8, 9)

Figure The standard run of the Limits to growth finds that human population size declines in the 21st century. If so, this implies a phenomenon of “peak health”(10), likened to peak oil. After Turner.(11) Figure forthcoming.(12)

Although the long version of the early Planetary Boundaries study(13) acknowledges a debt to the Limits to Growth,(14) the Planetary Boundaries work only hints at the effects on health, well-being and civilisation, should too many boundaries be transgressed. Perhaps its authors (of whom few if any would be recognised as leading social scientists) wisely sought to leave such considerations to other writers, aware of the furore encountered by the authors of the Limits to Growth and other bearers of bad news, from Malthus to the Ehrlichs(15) and Lester Brown.(16)

Planetary Health literature draws extensively on the Planetary Boundaries framework, but seems to shy away from mentioning the Limits to Growth.(14) Nonetheless Planetary Health courageously extends Planetary Boundaries towards a domain where controversy and perhaps vilification await, fates experienced by other health writers who have attempted to sound the alarm.(17)

Malthusian checks in 2017 and the role of inequality in shaping Our Common Future

Optimists contend that market forces and ingenuity will continue to long outwit limits, even as famines have returned to parts of sub-Saharan Africa and Yemen,(18) and as awareness and apprehension of the enormous scale of future refugee numbers increase, including by the military.(19) The suffering of 600,000 Rohingya, driven from Myanmar in 2017, is but one recent example, a flight not driven by climate change, but other aspects of Limits to Growth, including limited tolerance and co-operation.(12)

It is important to recognise that policies and views are shaped by those with the greatest military and economic power, whose influence permeates the scientific literature and academic appointments. Civilisation remains extremely unequal, with a global Gini co-efficient (a widely used measure of inequality) which far exceeds the most unequal individual nation.(20) This inequality is mentioned in planetary health scholarship but is probably generally interpreted as a call for greater health justice. This call is valid, but in my view, there is insufficient appreciation, including within planetary health writing, that the extent of inequality helps propel civilisation towards a brink, essentially because elites feel disconnected from the masses, and immune to whatever perils lie ahead.(21, 22)

The release of the Paradise Papers(23) shows, again, the scale of legal tax evasion which results from and fuels global inequality.(24) Prestigious companies and at least one anti-poverty campaigner, Bono, have been revealed as participating in this. It is as if powerful individuals and companies distrust society, thinking their personal control of resources will do more good. But such individualism is a recipe for collapse. We need a return to the idealism at the birth of the United Nations, born from sober judgement, following two World Wars,(22, 25, 26) and we need more courage in academic and political spheres.

Acknowledgements: Thanks to Dr Graham Turner for providing the data in the figure, Dr Devin Bowles and Professors Andy Morse and Jouni Jaakkola for helpful comments

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