World scientists’ warning: The behavioural crisis driving ecological overshoot
Joseph J Merz, Phoebe Barnard, […], and Rory Sutherland+8
ABSTRACT
Previously, anthropogenic ecological overshoot has been identified as a fundamental cause of the myriad symptoms we see around the globe today from biodiversity loss and ocean acidification to the disturbing rise in novel entities and climate change. In
the present paper, we have examined this more deeply, and explore the behavioural drivers of overshoot, providing evidence that overshoot is itself a symptom of a deeper, more subversive modern crisis of human behaviour. We work to name and frame this
crisis as ‘the Human Behavioural Crisis’ and propose the crisis be recognised globally as a critical intervention point for tackling ecological overshoot. We demonstrate how current interventions are largely physical, resource intensive, slow-moving
and focused on addressing the symptoms of ecological overshoot (such as climate change) rather than the distal cause (maladaptive behaviours). We argue that even in the best-case scenarios, symptom-level interventions are unlikely to avoid catastrophe or
achieve more than ephemeral progress. We explore three drivers of the behavioural crisis in depth: economic growth; marketing; and pronatalism. These three drivers directly impact the three ‘levers’ of overshoot: consumption, waste and population. We
demonstrate how the maladaptive behaviours of overshoot stemming from these three drivers have been catalysed and perpetuated by the intentional exploitation of previously adaptive human impulses. In the final sections of this paper, we propose an
interdisciplinary emergency response to the behavioural crisis by, amongst other things, the shifting of social norms relating to reproduction, consumption and waste. We seek to highlight a critical disconnect that is an ongoing societal gulf in
communication between those that know such as scientists working within limits to growth, and those members of the citizenry, largely influenced by social scientists and industry, that must act.
For Will Steffen (1947–2023), one of the kindest advocates for our planet in a time of crisis.
‘The conscious and intelligent manipulation of the organized habits and opinions of the masses is an important element in democratic society. Those who manipulate this unseen mechanism of society constitute an invisible government which is the true
ruling power of our country. We are governed, our minds are molded, our tastes formed, our ideas suggested, largely by men we have never heard of’.
– Edward Bernays, Propaganda, 1928
‘A species causing the extinction of 150 species per day doesn’t need more energy to do more of what it does’.
– Hart Hagan, Environmental journalist

INTRODUCTION
Modern humans and millions of other species face an unprecedented number of existential threats due to anthropogenic impacts exceeding our planet's boundaries.1 We are in dangerous territory with instability in the known realms of biosphere integrity,
land system change and novel entities such as plastics and synthetic toxins, climate change, freshwater change and biogeochemical flows.
Considering the dynamic, closed and interconnected nature of Earth's systems together, these threats pose an increasingly catastrophic risk to all complex life on Earth. Many scientists privately believe it to be already too late to avoid the tipping
points that will trigger devastating and irreversible feedback loops.2
It is increasingly acknowledged that all of these threats are symptoms of anthropogenic ecological overshoot. Overshoot is defined as the human consumption of natural resources at rates faster than they can be replenished, and entropic waste production
in excess of the Earth's assimilative and processing capacity.3–7
In this paper, we explore the behavioural drivers of overshoot, providing evidence that overshoot is itself a symptom of a deeper, more subversive modern crisis of human behaviour. We work to name and frame this crisis as ‘the Human Behavioural Crisisâ€
™ and propose the crisis be recognised globally as a critical intervention point for tackling ecological overshoot. We demonstrate how current interventions are largely physical, resource intensive, slow-moving and focused on addressing the symptoms of
ecological overshoot (such as climate change) rather than the distal cause (maladaptive behaviours). We argue that even in the best-case scenarios, symptom-level interventions are unlikely to avoid catastrophe or achieve more than ephemeral progress.
In the final sections of this paper, we propose an interdisciplinary emergency response to the behavioural crisis by, amongst other things, the shifting of social norms relating to reproduction, consumption and waste. We seek to highlight a critical
disconnect that is an ongoing societal gulf in communication between those that know such as scientists working within limits to growth, and those members of the citizenry, largely influenced by social scientists and industry, that must act.
Scientists working in limits to growth must join forces with social scientists not only in academia but critically with the non-academic practitioners of applied social and behavioural science. Not only are such practitioners demonstrated masters in the
theory of driving behaviour change but crucially also masters of the practical implementation of that theory in the real world.
Lastly, we will provide a possible frame through which to view our species’ ability to consciously drive large-scale behavioural change as an opportunity unavailable to most other species. An implementation of such a framework limiting widespread
maladaptive behavioural manipulation may ensure human appetites remain within planetary boundaries, and be key in unlocking a truly prosperous and sustainable future for H. sapiens on Earth.
This paper is not intended to be an exhaustive roadmap to address the behavioural crisis, instead it should be taken as a call to action for interdisciplinary collaboration to achieve just that.

SCOPE
In this paper, aside from reproductive behaviours which we mention below, our focus is largely confined to socially constructed attitudes, values and behaviours that encourage unnecessary personal consumption, and which have led the world into a state of
overshoot.
This focus is critical because, to date, a mere quarter of humanity – the wealthy quarter – is responsible for 74% of excess energy and material use.8 This, when taken alone, is sufficient to propel the human enterprise into overshoot.
Meanwhile, the quarter of the global population who live below the USD $3.65 poverty line, and the almost half, 47%, who live below the USD $6.85 poverty line9 aspire to achieve equivalent high-end lifestyles, encouraged, in part, by the constant barrage
of advertising. To achieve this would certainly increase greenhouse gas emissions, deplete many essential renewable resources from fish-stocks to arable soils and strain global life-support to breaking point, including the risk of triggering runaway
hothouse Earth conditions.10
We acknowledge that there are many other relevant behaviours and considerations, including genetic pre-dispositions to consume, the role of temporal, spatial and social discounting, socio-political factors (e.g. status hierarchies) and even addiction to
conspicuous consumption.
Repeated rewarding experiences help shape the synaptic circuits of the developing brain, predisposing the individual to seek out similar experiences that reinforce the already preformed circuits and to deny or reject contrary inclinations or information.
11
We also acknowledge that part of our focus, on media and marketing manipulation, is just one example of how intentional behavioural manipulation undermines planetary and social health. There certainly are other examples – such as how firms and
governments limit more sustainable options either by design or consequence. In essence, power dynamics in society underlie the manipulation of needs, wants and desires. This is crucial for understanding how our human predisposition for potentially
maladaptive behaviours has been twisted to become actually maladaptive. While we humans are fully capable of regulating ourselves, power dynamics in societies often overcome this. Better understanding this within different societies, and how it
perpetuates our ‘polycrises’, will help us move into a wiser and more sustainable civilisation.
In regards to reproductive behaviours, population growth plays, and will continue to play, a significant role in ecological overshoot. Across the globe, the middle class is the fastest-growing segment of the population, projected to grow another billion
to reach 5 billion by 2030.12 Over the coming decades, the majority of projected population growth will be concentrated in the developing world,13 where the average standard of living must be raised through increases in per-capita consumption. As a
result, however, their ecological footprints are likely to increase towards those of the Global North.
Proponents of ‘green growth’ may argue that there is a way to avoid this, however, ‘the burden of proof rests on decoupling advocates’.14
To avoid ecological breakdown ‘incrementalist propositions along the lines of green growth and green consumerism are inadequate. The ideals of sufficiency, material thresholds and economic equality that underpin the current modelling are incompatible
with the economic norms of the present, where unemployment and vast inequalities are systematic requirements, waste is often considered economically efficient (due to brand-protection, planned obsolescence, etc.) and the indefinite pursuit of economic
growth is necessary for political and economic stability’.15
Even the relatively conservative IPCC views population growth as a significant factor in climate change (a single symptom of ecological overshoot).16 Additionally, a recent paper found that population growth has cancelled out most climate gains from
renewables and efficiency from the last three decades.17 For these reasons and more, we have not gone into detail on certain aspects of population dynamics. Instead, we have rooted this paper in ecological economics where population – at any level –
plays an important role.
We call for additional research to develop a full understanding of the many dimensions of the behavioural crisis and how we can best address it.

PREVIOUS SCIENTISTS’ WARNINGS
The initial ‘World Scientists’ Warning to Humanity’ was published in 1992,18 starkly emphasising the collision between human demands and the regenerative capacity of the biosphere. It was followed by a further report, ‘World Scientists’ Warning
to Humanity: A Second Notice’19 which confirmed that the intervening 25 years had merely accelerated environmental destruction driven by a global population increasing by more than 40% – some 2 billion humans. The ‘World Scientists’ Warning of a
Climate Emergency’ report,20 so far endorsed by 14,859 scientists from 158 countries, proposed a range of measures for restoring and protecting natural ecosystems, conserving energy, reducing pollutants, reducing food waste, adopting more plant-based
diets, stabilising population and reforming the global economy.
Subsequent warnings from the scientific community have added to the evidence of overshoot including insect extinctions,21 the impact of climate change on microorganisms,22 the freshwater biodiversity crisis,23 endangered food webs,24 invasive alien
species,25 the degradation of large lakes,26 the illegal/unsustainable wildlife trade,27 the role of affluence,28 tree extinctions,29 an imperilled ocean,30 and population growth as a specific driver.31 These papers are gathered on the Alliance of World
Scientists website.
Despite so many warnings, there has been a marked lack of action, driving several of us to co-author a ‘World Scientists’ Warnings into Action, Local to Global’ paper,32 so far endorsed by over 3,000 scientists from more than 110 nations, to set
out a framework for concrete action to curb our hyperconsumption of resources. This paper focused on the same six key issues (energy, pollutants, nature, food systems, population and the economy, plus governance and leadership), and on three timelines to
2026, 2030 and 2050. None of the key issues identified by the authors are isolated problems; they are all symptoms of human ecological overshoot.
In the present paper, we contend that an underlying behavioural crisis lies at the root of ‘overshoot’ and probe the implications for humanity if we are to retain a habitable planet and civilisation. While human behaviours were implicit in the
various world scientists’ warnings, we believe they need explicit attention and concerted emergency action in order to avoid a ghastly future.33

HUMAN BEHAVIOUR DRIVES OVERSHOOT
The main drivers of anthropogenic ecological overshoot are human behaviours and cultures relating to consumption8,28 and population dynamics.31,34 These two factors are mathematically, though certainly not linearly, related. Like other species, H.
sapiens is capable of exponential population growth (positive feedback) but until recently, major expansions of the human enterprise, including increases in consumption and waste, were held in check by negative feedback – e.g. resource shortages,
competition and disease – which naturally curbed continued population growth.7
H. sapiens took around 250,000 years to reach a global population of 1 billion in 1820, and just over 200 years to go from 1 billion to 8 billion. This was largely made possible by our species’ access to cheap, easy, exosomatic energy, mainly fossil
fuels. Fossil fuels enabled us to reduce negative feedback (e.g. food shortages) and thus delay and evade the consequences of surpassing natural limits. In that same 200 year period, fossil energy (FF) use increased 1300-fold, fueling a 100-fold increase
in real gross world product, i.e. consumption, and the human enterprise is still expanding exponentially.7 We are arguably in the late boom phase of a one-off boom-bust cycle that is driving us rapidly beyond the safe harbour of planetary boundaries
towards chaotic collapse and worse (Figure 1).5,7

Figure 1. Ecological overshoot in number of Earths required. Data from Global Footprint Network – June 2023.
In this paper, we use the term ‘behavioural crisis’ specifically to mean the consequences of the innate suite of human behaviours that were once adaptive in early hominid evolution, but have now been exploited to serve the global industrial economy.
This exploitation has accumulated financial capital – sometimes to absurd levels – for investors and shareholders, and generated manufactured capital (‘human-made mass’) that now exceeds the biomass of all living things on Earth.35 Significantly
manipulated by the marketing industry, which several of us represent, these behaviours have now brought humanity to the point where their sheer scale – through our numbers, appetites and technologies – is driving ecological overshoot and threatening
the fabric of complex life on earth.
These behaviours are related to our previously highly adaptive, but now self-defeating, impulses to:
•
seek pleasure and avoid pain;
•
acquire, amass and defend resources from competitors;
•
display dominance, status or sex appeal through size, beauty, physicality, aggression and/or ornamentation;
•
procrastinate rather than act whenever action does not have an immediate survival benefit particularly for ourselves, close relatives and our home territories (humans are innate temporal, social and spatial discounters).
Many of our continuing environmental and societal challenges arise from these hijacked impulses. In a global economy that strives to create and meet burgeoning demand, rather than fairly and judiciously apportioning supply, these behaviours are
collectively highly maladaptive, even suicidal for humanity.1

DRIVERS OF OVERSHOOT BEHAVIOUR
The evolutionary drive to acquire resources is by no means exclusive to the human animal. In H. sapiens however, the behaviours of overshoot are now actively promoted and exacerbated by social, economic and political norms largely through the intentional,
almost completely unimpeded exploitation of human psychological predispositions and biases. Here, we explore what we consider to be three critical drivers in the creation and continuation of the human behavioural crisis.

Economic growth
----------------
Economists define the ‘economy’ as all those organised activities and behaviours associated with the production, allocation, exchange and consumption of the valuable (scarce) goods and services required to meet the needs and wants of the
participating population. But this is a simplistic, limited definition. An ecologist might describe the economy as that set of behaviours and activities by which humans interact with their biophysical environment (the ecosphere) to acquire the material
resources required for life, and to dispose of the waste materials that result from both our biological and industrial metabolisms. Economic accounts should therefore record all the energy and material ‘throughput’ from the natural world through the
human subsystem and back into nature; they should even account for those produced goods that do not enter formal markets, as these add to gross material consumption. In other words, human economic behaviour helps define the human ecological niche, the
role H. sapiens plays in interacting with, and altering the structure, function and species composition of, the ecosystems of which we are a part. From this perspective, economics really should be human ecology. But it is not.
Today's dominant neoliberal economics conceives of the economy as a self-generating ‘circular-flow of exchange (monetary) value’ that operates separately from, and essentially independent of, the natural environment.36 We generally measure the scale
of economic activity in terms of gross national product, i.e. the abstract monetary value of final goods and services produced in a country in a specified time period. Physical natural resources (i.e. ‘the environment’) are seen as merely one of
several interchangeable ‘factors of production;’ should a particular resource become scarce, we need only increase the input of other factors (capital, labour, knowledge) or depend on rising prices to stimulate some engineer to find a substitute.37,38
The same simplistic thinking conceives of humans as self-interested utility maximisers (i.e. ‘consumers’) with unlimited material demands and no attachment to family or community. It was easy for modern techno-industrial society to make the leap from
believing that the economy is untethered from nature, people essentially insatiable and human ingenuity unbounded, to accepting the notion of unlimited economic growth fostered by continuous technological progress. This helps explain why real gross world
product has ballooned 100-fold, and average per capita income (consumption) has increased by a factor of 14 (twice that in wealthy countries) since the early 1800s.39
Interestingly, most people seem unaware that this explosion was made possible not only by improving population health but, more importantly, through technologies that use fossil fuels – coal, oil and natural gas. Fossil energy is still the dominant
means – 81% of primary energy in 2022 – by which humans acquire sufficient food and other resources to grow and maintain the human enterprise. Between 1800 and 2021, global FF use increased by a factor of 1,402, from just 97 TWh to 136,018 TWh.39
The average world citizen today uses 175 times as much FF as his/her counterpart in 1800. Remarkably, we humans have burned half the FFs ever consumed and emitted half our total fossil carbon wastes in just the past 30 years.40

Marketing
----------
Up until the early twentieth century, marketers focused on functional differentiation. The effectiveness of their work was largely contingent on its ability to ‘spotlight’ functional reasons to buy specific products when people needed them.41 In
essence, the role of marketing was to connect functionally differentiated products with willing buyers. As markets matured, however, competition intensified, and businesses looked to find better ways to differentiate themselves beyond the purely
functional.
Around this time, Sigmund Freud's nephew, Edward Bernays, began experimenting with his uncle's psychoanalysis work to develop techniques for widespread behavioural manipulation. Bernays later termed this The Engineering of Consent, describing it as the â€
˜use of an engineering approach – that is, action based only on thorough knowledge of the situation and on the application of scientific principles and tried practices to the task of getting people to support ideas and programs’.42 Bernays
successfully commercialised his work and is commonly regarded as one of the founders of the public relations industry. This novel approach, along with others developed in advertising agencies around the globe, proved highly influential on the way
products were marketed and sold to consumers.
Suddenly, marketing effectiveness was no longer determined by its ability to ‘raise awareness’ or harvest existing demand but by its ability to deepen and diversify the needs and wants that could be met through personal consumption.43 This paradigm
shift meant that business growth was no longer constrained by people's mere biological requirements, it could instead be unlocked by attaching greater meaning to an effectively infinite number of market offerings.
In this brave new world of unchecked business growth, multinationals were no longer marketing hygienic toothpaste, but a mint-flavoured confidence boost – a maintenance purchase was suddenly something that could make you feel more attractive. Cars were
no longer being sold based on their functional superiority (i.e. space, speed, comfort, price), but by what they suggested about you as a person (i.e. status, sexiness, rebelliousness, appetite for adventure).
In an era saturated by brands and marketing, consumption has become less reflective of our physical needs and more reflective of our runaway psychology. For example, we may buy to boost our mood, reinforce our identity44 or elevate our social status
above others.45
The targeting of consumers has become increasingly effective through the collection and use of data and analytics. The collection and sale of individuals’ personal data is rampant. Unsurprisingly, tech giants like Google and Facebook are amongst the
most active in this space. These companies track and sell not only what consumers view online but also their real-world locations through what is known as RTB (Real-Time Bidding).
In the US, users’ personal online data is tracked and shared 294 billion times each day (for your average American, that's 747 times per day). In Europe, that figure was found to be 197 billion times (Google alone shares this personal data about its
German users 19.6 million times per minute). Combined that's 178 trillion times per annum.46 All this leads to incredibly detailed data about individual user behaviours and preferences. In fact, a 2017 report found that by the time a US child reaches 13
years old, Ad Tech companies hold an average of 72 million data points on that child.47
The subsequent egregious overconsumption, which in combination with the resulting creation of waste, disproportionately multiplied by population, gives the wealthy a far greater negative environmental impact than the poor.8 Individuals with incomes in
the top 10% are now responsible for 25–43% of environmental impact and 47% of CO2 emissions, while the bottom 10% contribute just 3–5% of environmental impact,28 and the bottom 50% contribute only 10% of CO2 emissions.48 A recent report found the top
20 wealthiest individuals on Earth produce 8000 times the carbon emissions of the poorest billion people.49
For sustainability, reductions in FF and material consumption between 40% and 90% are necessary.50,51 This may seem unattainable without a proportionate loss in living standards; however, affluent countries exist far beyond sufficiency. In fact, ‘the
drastic increases in societies’ energy use seen in recent decades have, beyond a certain point, had no benefit for the well-being of their populations – social returns on energy consumption per capita become increasingly marginal’.15 As such,
multiple studies now demonstrate per-capita energy consumption in many affluent countries could be decreased substantially and quality living standards still maintained.15,52–54

Pronatalism
-------------
Reproductive decision-making is assumed to be a largely personal choice, free from the constraints of cultural and institutional norms. As a result, discussion of reproduction as it relates to environmental degradation and ecological overshoot is often
met with concern regarding impingement of people's personal desires, rights and actions. However, human reproductive behaviours, like most other behaviours, are greatly influenced by cultural norms and institutional policies and deserve to be
investigated critically.55,56
Pronatalism is a set of social and institutional pressures placed on people to have children, often driven by forces such as patriarchy, religion, nationalism, militarism and capitalism.57 Pronatalism exerts enormous influence on people and their choices.
•
Positive feedback is often expressed through glorification of motherhood and large families, financial incentives and subsidies for childbearing, including through assisted reproductive technologies.
•
Negative feedback is expressed through stigmatisation of use of contraceptives, abortion and lifepaths that do not fit dominant cultural narratives, such as single adults, childless and childfree people, LGBTQIA+ people, adoptive families, those who
regret parenthood or those who do not have the ‘right’ number of children.58
Depending on the degree of patriarchal and institutional control in a given culture, stigma can take the form of physical and emotional abuse, divorce, economic marginalisation and social ostracisation.56 The degree of policing individual parenting
choices strongly determines the degree of conformity by individuals in a culture or community. This explains why women's stated preferences for number and timing of children vary in accordance with the norms of the community in which they reside.55
Anthropological studies of later hunter-gathering societies as well as evidence of very early agricultural groups show that the shift to settlement societies led to a systematic diminution of female status, as women went from being active gatherers of
food to being relegated to the home sphere, as males dominated the fields. The subsequent rise in population, cities and tribal conflict over land and power created the need for more laborers and warriors, which raised the value of women as child bearers
to the exclusion of other roles, thereby underpinning the beginnings of pronatalism.59
Due to the dangers associated with pregnancy and childbirth, as well as the laborious process of child-rearing, certain ‘social devices’ had to be employed to make reproduction appear more desirable, thereby population increase would offset the
wastage of war and disease.60 Social devices including the institutions of law, religion, media, education and medicine were used to promote and reinforce the universal idealisation of pregnancy and motherhood.
Over the last 200 years, improvements in public health, medicine, disease control and sanitation – all of which occurred on the back of fossil-fuelled industrialisation – significantly lowered the risk of dying, especially amongst children, leading
to unprecedented growth in the human population. Pronatalism remains deeply embedded within institutional policies and norms that glorify and reward reproduction to serve external demographic goals – capitalism, religion, ethnocentrism and militarism
amongst others.
Despite great advances in gender equality and opportunities for women in education and the economy over the last several decades, pronatalism remains a strong pillar in many societies. Most religious traditions have strong pronatalist teachings and
scriptural mandates to ‘be fruitful and multiply’, further buttressed through misinformation about contraceptives and abortion, and proscriptions on their use.57,58 Economists, political leaders and corporate elites regularly argue that keeping
fertility high ensures a steady supply of workers, consumers and taxpayers, while generating a larger pool of potential inventors.58
Neoliberal economic interests are also enacted through popular media and culture that perpetuate pronatalist narratives. From product advertising and women's magazines glorifying motherhood, and celebrity gossip fixation on the ‘biological clock’ and
‘baby bump’, to popular movies and television programmes that use pregnancy to ‘complete’ the character arc of a protagonist. The marketing, media and entertainment industries exert an enormous influence on people's reproductive decision-making.61
Meanwhile, neoliberal feminism – feminism of the privileged colonised by neoliberal ideology – seeks to advance political goals and enhance market value and has only reinforced the mandatory-motherhood narrative by advocating for women to ‘have it
all’, a goal unattainable for the majority of women around the world. This new form of feminism has conveniently been exploited by the assisted reproductive technology industry, growing annually by 9%, with projected growth to a global $41 billion
industry by 2026 to market medically dubious technologies such as egg freezing to increasingly younger women.62–64
Concerns about overpopulation in this century led authorities and advocates to institute campaigns and policies to reduce fertility rates. The majority of these policies, which employed measures to combat pronatalism by providing women the means to
control their own fertility through access to education and family planning, proved extremely effective. Countries as diverse as Thailand, Indonesia and Iran saw their fertility rates drop from over six to under two in a matter of decades.65 On the other
hand, coercive policies such as China's one-child policy, and forced abortion and sterilisation campaigns in Puerto Rico and India, not only led to egregious violations of human and reproductive rights but they also backfired. They created the disastrous
legacy of tainting all family-planning campaigns – including the majority that have focused on liberating women – with the blemish of coercion.34,65,66 These draconian measures not only led to widespread suspicion of any efforts towards population
reduction and stabilisation but they also had the opposite effect of strengthening and legitimising the centuries-old form of reproductive control: pronatalism.56 Currently, half of all pregnancies globally are unintended and 257 million women are unable
to manage their own fertility due to oppressive pronatalist norms within their communities.67

[continued in next message]

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)