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The literature on sustainability science is now vast. This article is an attempt to summarize current thinking as best I can, directing the reader to important sources. An international approach to global problems depends on a bedrock of shared values and objectives. The universal ethic advocated here is that of human wellbeing (happiness or flourishing) and management objectives that are backed up by the world’s best science. For a discussion of human flourishing, well-being, and happiness as a global ethic see here also morality and sustainability.

Concerns about sustainability arose out of the environmental movement in the 1960s when it became clear that the dramatic increase in human population (the Great Acceleration) was having an adverse effect on the biosphere. As globalization creates a world that is more interconnected and interdependent, so the need for international cooperation increases. Climate change is a prime example of a problem whose solution requires international cooperation .



The Earth Charter

We stand at a critical moment in Earth’s history, a time when humanity must choose its future. As the world becomes increasingly interdependent and fragile, the future at once holds great peril and great promise. To move forward we must recognize that in the midst of a magnificent diversity of cultures and life forms we are one human family and one Earth community with a common destiny. We must join together to bring forth a sustainable global society founded on respect for nature, universal human rights, economic justice, and a culture of peace. Towards this end, it is imperative that we, the peoples of Earth, declare our responsibility to one another, to the greater community of life, and to future generations.

The Earth Charter Movement

How can we be best prepare for the future?

The Earth Charter (above) is a document that outlines a way of turning conscience into action. It does this through four pillars: respect and care for the community of life; democracy, non-violence, and peace; ecological integrity; and social and economic justice. These four pillars are then elaborated in sixteen principles.

Global values

The Earth Charter provides a simple and appealing statement of intent as it attempts to establish a shared set of international values. Our common or universal values can be expressed in even simpler, more basic, terms as the universal shared aspiration to attain human flourishing (collective wellbeing or happiness).

The collective aspiration to create the best possible future for planet Earth, the community of life, and future human generations began in the 1960s as we became increasingly aware of our collective role as custodians of planet Earth.This is a complicated question that involves our values, the way we manage both our individual lives and society, the kind of economy we use to serve our needs, and the care that we take of our environment, planet Earth.

In principle, we have political parties to enact our collective vision for the future, but if your sentiments match those of the Earth Charter then there is much work still to be done.

The international program that sets out to implement the values of the Earth Charter –  creating the best possible world for future generations – uses the word ‘sustainability’ to express this ambitious objective.

This article examines some of the key factors to be considered if we are to think seriously about what ‘sustainability’ means.

What is sustainability?

The word ‘sustainability’ has been chosen by the United Nations to indicate global programs established to create the best possible future for planet Earth, the community of life, and future human generations. This requires international cooperation in the  management of three key interdependent components of our individual and collective lives – the environment, society, and the economy – what the United Nations refers to as ‘the three pillars’.

Balancing the sometimes conflicting demands of these three pillars is extremely difficult.

Economists point out that without flourishing economies such ambitious international programs could not proceed:  economies provide the jobs and growth on which all human flourishing depends.

Environmentalists point out that all human activity depends on natural resources, some of which are limited in supply. The unregulated consumption of natural resources by a rapidly increasing human population has significantly altered the Earth’s biogeochemical cycling to a point that has prompted the proposal for the establishment of a new geological epoch, the Anthropocene.

Sociologists know that without adequate governance and efficient, stable social organisation a united approach to the future is impossible.

Working together can be difficult. We all perceive the world from our own particular background, training and experience, keenly defending our own interests – but we must work together as best we can.

Managing sustainability

This is a difficult balancing act that depends on economic security, good governance and social stability. We want a global economy with an equitable distribution of resources that are not being harvested beyond the carrying capacity of the planet.

Managing sustainability is extremely complicated because it can and must be tackled at any scale from local and individual to global . . . from, say, international legislation to the way we conduct our individual lives.

This article will examine the individual, national, and global scales.


For environmentalists the challenge is to protect the natural environment because it is our life-support system. All human activity uses resources that come ultimately from our planet. These resources are almost infinite in number but they can be conveniently divided into five simple interrelated and easily-understood physical categories: energy, food, water, materials, and biodiversity (nature).

These five physical building blocks may be cross-references with the five major anthropogenic pressures on biodiversity: habitat loss and modification, overexploitation, pollution, invasive alien species, and climate change.

The more complex the social organization, the more complicated the ways in which these resources are woven into the social fabric. So, for example, a hunter-gatherer would use largely unprocessed local resources with perhaps a few items obtained by trade. Today’s society often uses highly processed products whose components are obtained from around the world: consider the skills and materials needed to build a computer.

Consumption itself is not necessarily a problem. Environmental sustainability is about decoupling the strong link between consumption and negative environmental impact. We can reduce consumption by deliberately using less resources and we can manage the cycle of production, distribution, use and disposal in a more sustainable way by reducing resource intensity and maximizing resource productivity per unit of resource.

Ideally policy would be based on scientific evidence obtained by measuring and monitoring environmental impacts using the same rigour that we apply to economics.

The Global Footprint Network

Mathis Wackernagel explains the relationship between human population and resource use:
see also the Global Footprint Network 

The pulse of plants sustaining the Earth

Plants are primary producers – food factories powered by sunlight. The Sun’s energy drives plant photosynthesis which builds up the plant matter that sustains all life on Earth – which includes our society and economy.

Gross primary production (GPP) shown here (click the link below), is the total amount of carbon dioxide ‘fixed’ by land plants per unit time.[11]

Humans now take about a quarter of the Earth’s primary productivity which is is now generated by agricultural and horticultural crops – as food for humans.

This cartogram animation from Worldmapper uses satellite observations from NASA’s Moderate Resolution Imaging Spectroradiometer (MOD17) which detects the seasonal pulse of the Earth’s primary productivity. This is much like the pulse of a human heartbeat. The animation shows how the changing seasons determine the variability of energy production throughout the year. Production depends on land surface (e.g. desert, forest, crops) and climate/weather, the tropics being highly productive, especially in the northern hemisphere’s winter.


The increase in social complexity needed for any community to provide security and a comfortable material existence for its citizens requires social stability and this is obtained through good governance – the integration of social, economic and environmental requirements in a way that protects society from unrest. Complex networks of government, trade, communication, and environmental protection that take so long to build up can be rapidly broken down. Of course the more complex a society, the more complex will be the governance needed to integrate its many activities.

Human impact on Earth’s ecosystems now threatens the well-being of both humans and the community of life. Alteration of the world’s biogeochemical cycles by human activity has prompted scientists to refer to the current geological epoch as the Anthropocene.[7] Creating a sustainable future for planet Earth requires a common international purpose expressed as a shared global ethic,[5] combined with an effective management strategy that integrates shared environmental, social, and economic values and goals. This ambitious international program has been in operation since the 1980s as the United Nations Program for Sustainable Development[4] and it deserves both our attention and support.

‘Sustainability’ means many things to different people. It is at once a value system, program for the future, and philosophy for life. Such a diffuse concept has both advantages and disadvantages. The advantage is that it is an open, democratic, flexible and stimulating source of ideas for discussion. The disadvantage is its imprecision, opacity, and apparent lack of direction, opening it to the accusation that it is more about goodwill than effective administration.

Though the idea of sustainability has its detractors, it is the nearest we have to a global rallying call for the future management of planet Earth. The general character and intention of the word ‘sustainability’ are now well understood and acknowledged world-wide. The goal of sustainability can only be reached by a process of measuring and managing – by employing sustainability accounting at all scales, from the global to the local and individual.


If societies are to flourish then they need time to devote to activities other than survival – there needs to be time for leisure and the development of technologies and intellectual pursuits that reduce the need for physical labour and time spent on routine tasks. Major historical steps on this path were the Agricultural Revolution (Agraria) when the capacity for food storage in settled societies enabled population increase and the development of trade specializations and technologies of scale (armies, ships, metalworking, pottery) that widened trade. The vast amounts of energy made available from fossil fuels during the Industrial Revolution (Industria) meant that this process of increasing the complexity of social organization underwent a great acceleration accompanied by a huge explosion in population. In general terms those societies that were more efficient at these tended to produce the civilizations and empires that dominated others. Today this process of social complexification continues as a revolution in information technology, trade and communication.

The social organism

To determine what is sustainable, we need a representation for the way societies get things done so that we can anticipate and manage, as best we can, the consequence of changes to the interconnected parts. A biological simile can make a comparison between the operations of a society and the healthy integrated functioning of an intelligent living organism. This can assist us in thinking about the way societies grow, mature, and flourish . . . including the factors that contribute to their malfunction, senescence, and decay.


An organism is a unit of nature with a degree of self-regulating autonomy.

The activity of an organism, like a human, is controlled and integrated by its internal communication system (nervous system). Some of this happens unconsciously and automatically (the autonomic system) and some is controlled by the conscious deliberations of the central nervous system, the brain.
All life depends, in addition, on factors that exist outside their bodies, in the environment. Of these outside factors it is food that provides the energy and nutrients needed to maintain bodily functions (metabolism). Assimilated food is circulated through the body by the blood system, which also gathers waste products for disposal. Other resources from outside the body that are needed to sustain life include water, materials, and other organisms. With sufficient food and a healthy body an organism can survive, grow, reproduce, and flourish.

Humans are animals with creative brains that leverage their food-given biological energy using two kinds of tools, the material and mental technologies that have become cumulatively more energy-efficient over time. Material technology may be simple (like sharpened rocks and spades), or complex (like mechanical diggers and computers), while mental technology (or collective learning) may also be simple (like ideas and simple memes) or complicated like language and mathematics.

These, in simple terms, are the requirements for a healthy, flourishing organism.

This biological simile can now be transposed to society.


Society treated here as a self-regulating group of people generally sharing the same territory, political authority, cultural expectations, and social institutions (= living organism).

The coordination of social activity, decisions about administration, is its governance (= brain) facilitated by the communication system (=nervous system) while the activity itself, the way of ‘getting things done’, is its social organization ( = the functioning of a whole organism).[10] Social organization is maintained by social metabolism or economy (= biological metabolism), which is the production, distribution, and consumption of goods and services with the creation and disposal of waste. Social metabolism is driven by the biological energy derived from food (agriculture) that drives bodies and minds, plus additional energy from sources such as fossil fuels, nuclear, wind, hydro, and solar. The rate of growth depends primarily on the supply of biological energy, but also the other resources (= blood) needed to maintain social organization, such as water, materials, and other organisms (ecosystem services), the quantity and extent of the distribution or transport system (= blood circulation system) of energy in the major sectors contributing to social metabolism.

Modern societies, then, are powered by the biological energy derived from plant-based agriculture and fossil fuels (currently with an increasing use of renewables) which feed into the growth that results from the synergistic interaction of communication systems, distribution by transport systems, resource extraction by mining, production by manufacturing and industry, and infrastructure developed by systems of engineering and construction. All these systems benefit from the increased energy efficiencies provided by technology.

When the available energy and other necessary resources are plentiful, there can be growth with a corresponding increase in complexity of social organization, social metabolism, technology, and population numbers.

Increase in social complexity can, with access to sufficient energy, cross thresholds of scale, with dramatic changes in the character of the society resulting from social diversification and the development of new technologies.

People and the materials of the economy are distributed through society by the transport system ( = blood), while the coordination of all this activity is facilitated by the communication system ( = nervous system) which is integrated by a system of governance ( = brain).

This is a crude representation of how society works, but it has generated a toolbox of categories that we can use to understand social organization – its evolution and its decline.

These categories can be arranged into an operational principle:

Sustainability Principle 1 –

Social organization is powered by the social energy that drives the transport and communication systems that bind social metabolism operating on key sustainability resources. Social metabolism is coordinated by social governance. When resources are plentiful and carefully managed, these factors are mutually reinforcing (synergistic) inducing an acceleration in growth and  complexity of social organization, in social metabolism, technology, and population numbers.

Social organization in action

Another way of explaining the social organization of an operational society is by relating structures and functions, objects and processes.

What should be done

Community decisions about what should be done, the overall objectives and management of society and social metabolism, are a matter of governance – the political process of negotiation – the nearest a society and its social institutions can get to a consensus of values, attitudes, and beliefs, and the means for achieving objectives.

          government : legislature 

What can be done

Then how much can be done depends heavily on the quantity of energy available, that is, the type of energy used and the efficiency with which it is processed. The cycle of production and consumption, of input and output, of ‘getting things done’, we can call social metabolism or, if you prefer, ‘throughput’.
Excess energy is the vehicle for growth and expansion – in populations, physical structures, and economies.

administration : population : resources

The rate it is done

There is a strong connection between the efficiency of energy use by societies and their form of social organization. Until recently, plants have been the major source of energy, the availability of their energy giving rise to different forms of social organization depending on the type of plant energy used. Small tribes of nomadic hunter-gatherers eating wild plants (and meat derived from them) used their muscles for social activity (Natura). Settled farming communities ate domesticated animals and plants to power their own muscles and those of domesticated animals, for social activity (Agraria). Industrial societies supplemented muscle energy with energy derived from the plant energy of fossil fuels which was used with machinery in the production of food and manufactured goods that greatly accelerated social activity and output (Industria). Today our information-rich society uses both the plant energy of Agraria and the fossil fuels of Industria while increasing the proportion of non-plant renewable energy (Informatia).

The resources on which a society depends are many, but these can be broken down into five simple and interrelated operational categories: energy, food, water, materials, and ecosystem services.

As societies become more complex, so new capabilities emerge that were not previously possible. This is a consequence of scale. Large groups of men can assemble ocean-going galleons and well-equipped armies. Today a computer requires materials and expertise that are sourced from around the world. Conversely, as the scale reduces so does what can be achieved.

The rate at which things are done, the productivity, is enhanced by improving the way in which energy is used, and this is achieved with technology. This is the difference between a plough and a tractor, a bicycle and a jet aircraft, an abacus and an electronic computer. Technology is the tools we use to improve our social efficiency and, for many years technology was limited by the available energy.

A society is sustainable when it can maintain social organization over the long term. The form of social organization depends largely on the availability of energy. Modern societies with sophisticated infrastructure, technology, manufacturing, buildings, systems of transport and communication etc. consume and require vast amounts of energy if they are to continue in their present form. Historically societies have acquired the energy needed to grow and merge into a global operational unit. But there is a limit to growth that consumes more than it produces.

administration : technology : transport & trade : mining, manufacture, construction : communication

Social organisation

See social organization
The formula I = PAT provides a simple static mathematization of consumption but it lacks a social and temporal dimension: it does not explain how, over time, societies became organised in a way that facilitated population growth, new and more efficient technologies, and increasing affluence – this is a question for historians.

Social organisation (social development)[1] can be measured using a social development index that allows us to compare one society with another: it can be loosely defined as ‘the capacity to get things done’ (this does not necessarily imply that ‘getting things done’ is a good thing) whether intellectually, physically, technologically or in any other way. Although this capacity can be attributed to a host of factors (see social organisation) the point is simply made here that, over the course of history societies have tended to get more done, at an ever increasing rate, and with increasing environmental impact.


See population
We know that every human places an additional burden on the world’s resources. By recycling and careful management of consumption this burden can be minimized but never eliminated. Population size impacts sustainability in many ways that cannot be ignored.

About 10,000 years ago at the time of the Neolithic Revolution humans and their domesticated animals made up about 1% of the world’s vertebrate biomass. Today, after about 500 generations, this has risen to 98%, mostly as cattle and livestock.

To understand how social development has resulted in the aggregation of people into populations and how their use of technology for the consumption of resources (expressed in the simplest terms as water, food, materials, energy, and biodiversity as Ecosystem Services) and facilitated by transport and communication systems and this has in turn affected human impact on the physical environment.


As a general biological principle populations (and economies) will grow until restrained by factors that limit access to resources – e.g. famine, disease, and conflict.

The historical demand for biophysical resources has been managed by increasing supply which provides the stimulus for more population growth. Today, as economic growth has demanded more and more resources with corresponding demands on the environment the equation has shifted to regulating demand by curbing population growth and making existing processes, technologies, and products more sustainable.


Consumption of biophysical resources

The quantitative use of biophysical resources by any society can be described as the total ‘throughput’; a measure of economic activity. For simplicity global biophysical resources have been divided into five categories: materials, energy, food, water an biodiversity (animals and plants, their ecology and [ecosystem services] to humanity). These categories are not mutually exclusive but each is critical to human existence and therefore warrants special consideration. Of course the many ways in which these basic biophysical resources are used by any particular society depends on the social organisation of that society. In theory by careful sustainability accounting it is possible to relate expenditure (national, institutional, individual) to resource use and environmental impact. In practice this is complex, costly, and impractical but there are many ways in which it can be applied. For example, energy (or water) intensity is the amount of energy needed to produce a particular product, provide a particular service, or perform a particular task. We can measure and reduce the energy and water (and other) intensities of our activities.

Management of resources

Consumption can be tackled by managing the supply and demand of resources, and technology can be used to both increase and decrease environmental impact.

Ideally we need to consider the environmental impact of each product we consume from its design to its production, use, and disposal (lifecycle analysis) but this is an extremely costly and complex process, not least because impacts will vary according to local circumstances but we begin with an awareness of the situation. This can be illustrated at the global scale. Different regions of the world have different resources and biocapacities. Global trade is a way of distributing resources from those regions that are rich in a particular resource to those that are poor in that resource but producing a resource like wheat has substantial environmental impact so when a country imports wheat it is, in fact, exporting the environmental cost of producing that wheat. Countries with ecological recerves become ecological creditors while those that depend on the import of these ecological services become ecological debtors.

Ecological debtor-creditor
Global ecological debtor and creditor countries[6]


The complexity of environmental impact & environmental accounting

Environmental impact is measured using a toolbox of indicators, indices, and benchmarks among which are the Living Planet Index, Sustainable Society Index, and Ecological Footprint, Environmental Performance Index. Similar indicators exist in the social domain including the Human Wellbeing Index and Human Development Index. All these indicators look beyond the Gross Domestic Product which is the traditional measure of social achievement expressed in purely economic terms. Quantifying sustainability is sometimes referred to as sustainability science.[8]

Another way of addressing the environmental impact of resource consumption is to distil resource use into its simplest practical elements. In the simplest terms this boils down to our use of energy, water, materials, and food, and the impact this use has on biodiversity. We tend to think of negative environmental impact as wilful destruction but it is mostly just the result of our unchallenged need for housing (building materials, heating, appliances) transport (infrastructure and vehicles) food (mostly meat and dairy but also plant crops) and water. All activity (work) requires energy and the more energy that is readily available the greater the potential impact. Fossil fuels have transformed the planet.

Use of these methods is illustrated in two examples, one at national scale and one at the scale of the individual.

Social energy

Increasing the supply of social energy facilitates social growth. Usually described in simple terms as ‘economic growth’ – increase in transport, trade, communication, infrastructure – whose collective long-term consequences (though not necessary consequences) have included escalating population numbers with greater social complexity, interconnection, interdependence, and knowledge accumulation. Much of this social energy was provided historically by plant-based fossil fuels.


One approach to sustainability is to recognize that humans and nature are coupled into a globalized social-ecological system with few ecosystems not influenced by people, and all people need ecosystem services – recognizing that our economy and society are closely integrated with the planet and its biosphere – its air, water and land. Social-ecological resilience investigates tools that help us to live within natural planetary boundaries and to persist, adapt, and transform in times of stress.

An explanation of resilience given by Steven Lade of the Stockholm Resilience Centre.


This article on sustainability has discussed how the increase in efficiency of energy capture and use resulted in three plant-based phases of human history, each with increasing social organization: Natura (wild plants), Agraria (cultivated plants), and Industria (industry based on fossil fuels) followed by a fourth and current phase of Informatia (information technology) in which we are winding back the use of fossil fuels.

During Natura, the plant energy used to build social structure was generated by human muscle. During Agraria human muscles were supplemented by animal muscles and more efficient technology. The additional use of fossil fuels during Industria increased the pace of this process manyfold.

Social organization, both as physical structures and governance, ensured that energy was used efficiently to gather and process resources (social sustenance) in the production and distribution of food and other goods and services. This was facilitated by improvements in the energy-dependent key factors of technology, transport, and communication.

Collectively, these factors created the cycle of production and consumption (the social metabolism) that defines modern developed industrial societies following a path of increasing economic activity, more jobs, and expanding populations (growth).

This is a highly simplified biological metaphor for the operation of society which metabolizes resources in order to both survive and grow.
The more resources taken from nature, the greater the environmental impact. Today’s challenge is to minimize the negative environmental effects of this global social metabolism: to manage what is now called our ecosystem services.

Though not a conventional approach to history Sustainability Analysis draws attention to the biophysical resources underpinning human activity and the role that these have played in our history and that they will play in the future. Without these resources history would have been very different.

However, it does give focus to the factors that have influenced sustainability in the past and ways of thinking about it in the future. In particular it should give us insights into the way that past human activity has created our current situation and how we might use this knowledge to create a more sustainable future.

Sustainability analysis on this web site begins by comparing in broad terms the interaction of environmental, socio-political, and economic factors as they individually and collectively impact on sustainability governance. More precisely this is related to human governance ([social organisation]) and its relationship with consumption through population numbers, technology, and affluence through the use of basic resources expressed in simple terms as: materials, energy, food, water and biodiversity (animals and plants) together with the effects of transport and communication systems on resource distribution.

Sustainbility, its meaning and implementation is a complex matter that cannot be addressed here except in the most general of terms. The following statement attempts to encapsulate a number of the key ideas. The following statement is not intended as a definition but an attempt to draw together some of the key ideas.

Sustainability attempts to understand and quantify the way socio-economic organisation has (through population number, technology, affluence, transport and communication systems and other social factors) influenced the consumption of biophysical resources (water, food, materials, energy, and biodiversity) to affect future planetary sustainability.

Key points

  • ‘Sustainability’ is a useful word expressing the desire to create the best possible world for present and future generations
  • At the international scale this program requires universal values as goals to which all humanity can aspire
  • Happiness is the single value desired by all individuals which, at the social scale translates into flourishing societies
  • Plants are the planetary primary producers, providing the food energy on which all life depends
  • Humans appropriate about a quarter of the Earth’s primary productivity for agriculture
  • The increasing globalization of economic life and the human impact on the planet in the Anthropocene means that humans are, in effect, custodians of the future of planet Earth
  • Sustainability is focused on minimizing the negative effects of human consumption on the planet and community of life: climate change, loss of biodiversity, north-south poverty divide, rainforest destruction, proliferation of synthetic chemicals, depletion of freshwater aquifers, agricultural and industrial pollution, depletion of ocean fisheries
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The Earth from space

The Blue Planet
Image conveying the vulnerable complexity of the earth’s biophysical system
Courtesy NASA

World Citizen Badge




short term -> long term






population (urbanization)
material & symbolic culture


food & agriculture
transport & communic'n
manufacture & trade
mining & engineering
coll. learning - innovation




Raw materials


Self-reinforcing growth


The energy derived from the Sun, stored in plant tissue during photosynthesis, then used (as food) to power the bodies of living organisms. Most biological energy drives internal metabolic processes within organisms but some is transformed directly into social energy via muscles and brains.

The food energy needed to sustain an individual human body has remained about the same throughout history (though physically active people require more calories) at about 12,500 kJ. while the human body has an energy generating capacity (at basal metabolic rate) of around 80 watts (about 20 watts of this being used by the brain), about the same as an incandescent light bulb). To derive a physical 'feel' for what this means, a 100 watt light bulb works 1.25 times harder than our body, that is, 1.25 H-e or 1.25 human equivalents.


The energy that powers the social activity that may be directed towards the maintenance or enhancement of social organization.

The energy of human social activity is derived partly from the biological energy that powers human bodies, and partly from external sources like water, wind, animal muscle, fire and more recently, fossil fuels, nuclear fuels etc.

Historically, the proportion of social energy derived from human bodies has decreased over time to become negligeable today. Fossil fuels provided a concentrated, abundant, and cheap source of social energy that facilitated growth in populations and economies. The use of this energy has been leveraged by the increasing efficiency of technology as both material and mental tools.

Media gallery


What is sustainability?

Systems Innovation – 2018 – 3:31

Full Documentary

Systems Innovation – 2018 – 42:15

What is sustainable development?

United Nations – 3:15



Sustainability and AI

by The AI Element

First published on the internet – 1 March 2019

A diagram indicating the relationship between the ‘three pillars of sustainability’.
The economy is under social control while social organization is constrained by its environmental limits
Courtesy Wimimedia Commons – Ktucker – Accessed 16 October 2020

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