Sustainability

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.

Recognizing that humanity as a whole shares the stewardship of planet Earth, we begin the search for a better future by finding our common ground. In spite of differences in nationality, religion, ethnicity, politics, gender, and more . . . there are still many aspirations that we share. It is around these shared values that, together, we can build a better future.

Global values

Expressed in the simplest possible terms, we all share the desire for human flourishing (collective wellbeing or happiness). However, from this simple shared value we must build an international program of Earth stewardship for the future.

The Earth Charter (above) is a declaration of universal values – a document that outlines a way of turning good will into action by following four general principles:

Social and economic justice
Respect and care for the community of life
Democracy, non-violence, and peace
Ecological integrity

The Earth Charter provides a simple statement of intent as it attempts to establish a shared set of international values.

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, a period in which climate change is just one of many threats due to the negative impact of humanity on the biosphere.

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

Working together can be difficult. We perceive the world from our own individual backgrounds, training, and experience, instinctively defending our own interests . . . but we must work together as best we can.

Investigating future sustainability at the global scale will be greatly facilitated by developing a theoretical model and terminology for the historical interaction between the environment, society, and economy. This will also benefit the analysis of the historical relationship between humans and plants.

Historical sustainability

Ideally we need to know those factors that are both necessary and sufficient to best describe the full sweep of human history – the successful adaptation of communities to their circumstances – when viewed from the perspectives of the three pillars: environment, society, and economy.

For the academic this is a study in complex systems analysis. Economists have, for example, tried to ascertain the many factors that make up modern economies thus knowing the precise economic ‘lever’ to pull for a desired effect – but with limited success. The same is true of social systems. We need to minimize complexity, ambiguity, and confusion but without oversimplification. For our purposes especially, it is important that the analytical categories be easily understood and applied.

History is change that is described in terms of both material objects (or structures), and functions (or processes).

Over time human systems have also become more complicated with new and more complex configurations of people and their material cultures giving rise to new properties and relations. In the list of analytical categories derived below, the simpler (more general) state is given outside the brackets and its historically emergent derivations inside the brackets.

What is presented here is a crude list of analytical categories that I have found useful in addressing the topics discussed on this web site.

Processes

The historically influential forms of energy-generated social organization have exhibited three important interrelated processes of change. First, an increase in complexity (complexification) resulting from the increase in numbers of individuals forming social groups and their interactions. Second, there is the mutually reinforcing synergy, an increasing collective momentum, of these interactions. Together these processes create the social metabolism that produces growth.

Growth (synergistic complexification)

Scale

The analytical categories most useful in historical analysis depend not only on the topic under investigation but also the scale of time and place. The article dedicated to scale illustrates this principle by discussing sustainability at the global, national, and individual scales.

The scale discussed here is long-term – the global history of humanity.

Framework of ideas

To assist analysis we need a system of ranked ideas, indicating how they are related to one-another. However, it is the ranking (prioritizing) of these categories that provides much of the historical debate.

As the topic is human history, then we must begin with humans and their communities.

Population & resources

In its simplest form, human history is about individuals that unite (populations) in the search for the basic resources that sustain life. To achieve even a small success requires coordinated cooperation directed towards common goals, it requires social organization. The basic resources needed to sustain life are many, but can be distilled into five practical everyday analytical categories: energy, water, materials, food, nature (ecosystem services)

So we have:

Population (social organization (governance) (law)(economy (goods and services))
Energy (resources ((energy, water, materials, food, nature (ecosystem services))))

Energy

All of these basic resources are needed for survival but there is a sense in which energy (activity) underpins everything. Physically, matter and energy are interchangeable and energy comes in many forms. However, for our purposes a distinction can be made between the energy that drives human bodies, and the energy that drives social activity which, depending on the mode of social organization, may consist to a greater or lesser degree of biological energy.

Energy (biological, social)

The sources of energy powering humanity in Natura were, ultimately, wild plants, in Agraria cultivated plants, in Industria fossil fuels, and in Informatia the transition to renewable energies.

Resource availability & geography

Long-term human history can be viewed as the search for unevenly distributed resources. It was therefore strongly connected to land (geography) and eventually became global in scale.

Land (geography)

Technology

Historically, it has been possible to access more resources in two major ways, by either finding new energy sources or by using existing sources for efficiently. On the one hand there was the transition to increasingly concentrated energies in the transition from wild plants, to cultivated plants (energy concentrated in cereal grains), to fossil fuels (the highly concentrated energy in gas, oil, and petroleum). On the other hand, energy – of whatever kind – could be harnessed more efficiently through the use of tools, which we refer to as technology. Technology is of two kinds, either ‘mental’ – the collective learning, like language and mathematics, that speed up and enhance what we do – or ‘physical’, like machinery and computers that also accelerate the business of ‘getting things done’.

Technology (collective learning (communication, innovation, education) and physical tools (construction, manufacturing, transport)

Technology is the single factor in human history that is most clearly cumulative and progressive. Improvements in technology are self-evident and can, in principle, be passed on and supplemented by subsequent generations.

The simple stone tools of the hunter-gatherer are the precursors to the wheels, ploughs, and the bronze and iron weaponry of Agraria, followed by the complex machinery of Industria, and the computers of Informatia.

The spoken language of hunter-gatherers of Natura was supplemented by the written language and mathematics of Agraria, the complex abstract theories that characterize Industria, and the artificial intelligence of Informatia.

Managing sustainability

The historical sustainability analysis above summarizes some of the factors to be taken into consideration when considering an equitable distribution of resources harvested within the carrying capacity of the planet. This is a difficult balancing act that can only be achieved with economic security, good governance, and social stability.

Environment

Environmentalists regard nature as the human life-support system but all human activity consumes resources taken from, and thus diminishing, nature. The resources we use have been processed to various degrees but they can be divided into five simple interrelated physical categories: energy, food, water, materials, and biodiversity (nature or, expressed in economic terminology, ecosystem services or natural capital).

These five elemental building blocks of human consumption generate five anthropogenic pressures on biodiversity in addition to species extinction: habitat loss and modification, overexploitation, pollution, invasive alien species, and climate change – major contributors to the worlds Sixth and most rapid Extinction Event.^[12]

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 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.

Society

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.

Economy

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.

Organism

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

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 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 organized 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.

Population

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.

Growth

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.

Resources

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.

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.

Resilience

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.

Commentary

The task of this article has been to establish those analytical categories most informative for assessing the future sustainability of humanity on planet Earth. This is a study in complex systems that will not be resolved here, but to make any progress at all we must have a framework of clear ideas. It helps to think of the world as a structured system of parts directed by processes towards functional ends.

The international sustainability agenda urges us to integrate, as best we can, three global systems for the mutual benefit of all: the environmental, social, and economic.

Scale

Big History has provided us with two key insights to begin this analysis.

First: the most productive historical analytical categories relate not only to the circumstances being considered but, more broadly, to the scale of time and place under consideration.

Second: when taking an overall long-term global view of human history (leaving short-term factors to be assessed by those better informed about short-term detail) the most productive analytical category to use is social organization.

Social organization

Social organization is the point of departure for the analysis of long-term human history passed through the filter of the three framing ideas of environment, society, and economy. These three systems are so tightly integrated that the allocation of analytical categories of structure and function to any one pillar becomes somewhat arbitrary.

Governance
As a means of developing public policy concerning social, economic, and environmental goals, governance lies outside the systems themselves. Traditionally, governance entailed systems of legislature associated in various ways with codes of behaviour, often established by religious institutions.

Technology
The synergistic influence of these three systems is most clearly illustrated by the use of
technology as the development of tools that make social organization – the business of ‘getting things done’ – more efficient. These tools are both mental (collective learning) and physical (materal culture) so closely bound to the ideas of social organization, economics and environmental impact that becomes a category most closely associated with social organization itself.

The following allocation of analytic categories to the three pillars of sustainability are my personal selection.

Long term environmental analytic categories

Today, in the Anthropocene, humanity is the primary custodian of the biosphere on which humans depend for their resources. The Sustainability Wheel reminds us of the intimate connection between ourselves, both individually and collectively, and the environment in which we evolved and on which we depend. The environment is not a human system itself but an integral part of the continuum that makes life possible.

Basic resources
We depend on the environment for resources which, expressed in the simple practical terms are: energy, materials, water, food, and the ecosystem services provided to humanity by the Earth’s biodiversity.

Energy
Though all these resources are crucial to life, it is energy capture and use that has had the greatest impact on social organization, determining both the growth rate of populations, and the intensity of their social metabolism.

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.

Long term social analytic categories

Population & urbanization
Humans are the basic units of social organization, resource consumption, and therefore sustainability analysis although it is as collective populations that their economic and environmental impacts are studied and through the historical trend towards increasing urbanization.

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.

Sustainability, 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