Prosperity within Material Boundaries
At the beginning of this year my family and I watched the 2018 TV series Lost in Space about the long and convoluted journey of the Robinson family to a new home on a far-away planet because the Earth had become inhabitable. Following their odyssey with its many detours was indeed engaging. Part of that journey was undertaken on an interstellar spaceship called the Resolute which sparked a discussion: how would one design a spaceship that allows people to live with material constraints on a very, very long journey?
The purpose of this story is to gather some thoughts on concepts of sustainable life, i.e. a system that supports life on a spaceship with physical boundaries, and how these, by extension, could be applied to an economic system on Earth. What could we learn from a spaceship about the operating conditions that allow prosperity within planetary boundaries on Earth? Perhaps viewing Earth as an interstellar spaceship helps to gain a new perspective on what is needed to make sustainable life on Earth possible.
Life on an Interstellar Spaceship
Suppose you were tasked with the design of concepts for life on an interstellar spaceship. The focus is not on the propulsion system or other important sub-systems of such a spaceship, but on the life support system that ensures for instance air, water and food supply and allows people to live, work and prosper within that system. People would still want or need do something I suppose on a long journey (assuming no cryogenic preservation).
From the start it is blatantly obvious that the spaceship is a self-contained system with clear boundaries: it is surrounded by empty space. Resources are limited to what can be brought on such a ship; once en route, the crew and its passengers would have to live with the means on board. It would be rather silly to consume all resources and live above the means. Consequently, the blueprint of the ship, or more specifically of the life support system on that ship, would have to be circular by design covering all aspects of life.
There have certainly been projects on Earth for such endeavours, and there is no doubt at lease one team working on such concepts at SpaceX. I reckon that there are a two major principles that must govern any design.
Conservation of Mass & Matter
For a very, very long journey every chemical element needed throughout the journey has to be and will be present at all times in one form or the other, an-organic as well as organic matter: water, oxygen, metals, carbo-hydrates, hydro-carbons, amino-acids, etc. Nothing can be added, and nothing (or nearly nothing) can leave the ship, everything has to be part of several cycles, be part of a system of cycles with a constant but recirculating mass.
For everything that is consumed (mostly by humans but also supporting machinery), there must be a process or a set of processes to recycle any waste and remake that consumable, however long and complex the cycle is. This is true whether it is food, paper, clothes, or even medicine. If you cannot bring along enough refined stuff, you need a process to make it, or even have the provision to create such a process. For instance, if tools have to be made from steel, perhaps a small furnace and smelter is needed.
Conservation of Energy & Entropy
Many processes involving living and non-living matter are irreversible, e.g. boiling water for tea which then inevitably cools down, or the wear & tear of machines, or the process of naturally decaying matter. In order to compensate and to maintain a certain level of complexity on the spaceship, energy has to be invested, i.e. an effort is needed to reinstate the material organisation or to transform matter from a lower back to a higher state of energy¹. Keeping the tea hot and beer cold requires energy. This energy cannot come from the internal circulation of matter, which rather consumes energy, but has to come from an external source such as solar irradiation (or possibly from a nuclear source converting matter into energy).
In summary, maintaining a certain state of complexity requires processes that are fuelled by energy. All that energy will be eventually converted to heat thus increasing entropy². In order to prevent the spaceship and all its contents to heat up and to maintain a certain temperature, however, all excess heat from all these irreversible processes has to be emitted into space. In the void of space, this cannot happen through heat transfer, but only through radiation, i.e. by radiating heat. Thus the spaceship can conserve a state of entropy, or in other words, the state of organisation of matter on board.
Principles for Life on a Spaceship
Given the constraints for the conservation of mass, matter, energy and entropy, the total amount of material items needed to support life is more or less constant, from clothes, shoes, food stuff, and all amenities life on the spaceship would afford. All these items have to be maintained, re-built or replaced. Assuming that there is a certain amount of energy needed to produce any material item, Eₚᵢ, and some energy to dispose of it, Eₛᵢ, both spread over the life time Tᵢ, as well as some energy to maintain the item in its state, i.e. some maintenance power Pᵢ, the sum total of all power needed to maintain the status quo of N material items would be something like:
In order to keep the total amount of power to a minimum, there are several and obvious candidates:
- minimalist lifestyle: keep the number of material items N to a minimum, to the essential that is really needed. Another term would be frugality.
- design for longevity: given the amount of embodied energy in any material item (as a function of the material and its production), make sure that it lasts for a long long time, i.e. Tᵢ, the denominator in the above equation needs to be large as it spreads the production and disposal energy over a longer period which makes the power smaller.
- keep recycling: make sure that a device can be easily dismantled once it reaches its end of life, minimising irreversible processes. Then all its constituents can enter the system of circulation, i.e. the disposal energy Eₛᵢ and production energy Eₚᵢ can be kept low, both together as the recycling energy. This rules out composite materials to a certain degree but will inform what kind of materials to use.
- energy efficiency: design the item such that it is as energy efficient it can be to keep the maintenance power as low as possible. This applies equally to the distribution of goods (with packaging) and mobility of people.
There is of course at least one snag in the system: in general, the quality of materials deteriorates in every recycling loop; for instance, one might start with high grade steel, but once recycled and mixed with other steel grades, more an more energy is needed to obtain high grade steel again. This is similar with paper or any other material need to support life in one way or the other. Consequently, the circular processes on a spaceship would be better off with few and simple devices that are more robust to the quality of recycled materials. Or, even better, circular life on a spaceship should make do with as little material support as possible.
On the upside, there is one aspect that is unique to a closed system: it can be analysed from the outset. All effects of all processes can be accounted for, in energy and resource terms. In other words, there would be no, or nearly no externalities, i.e. effects are within scope and planning horizon; they are all internal, literally, and can included in all analysis a-priori. Depending on the social and political organisation of life on the space ship, “free markets” could operate and regulate economic activity: cost should be strongly correlated to energy and resource requirements as well as to any detrimental effects. Hence, in such an ideal world, there would be no “market failures”.
Applying Spaceship Life Design Principles
If the objective of humanity’s life on Earth is prosperity for all humans, i.e. allowing every human being to flourish in equal measure, then the key question is: how can mankind achieve said prosperity within planetary boundaries? Perhaps thinking of planet Earth as a spaceship is helpful in conceiving a balanced economic system. It would be based on the acceptance of material constraints as well as on the conservation of mass, matter, energy and entropy. It would be a system that works with the means on-board, albeit a large amount, as well as on a system with regeneration capabilities.
Coupled Material and Economic Growth
As it stands in our current economic system, economic growth is coupled with material growth, which in turn is related to an accelerating consumption — production machinery. Simon P. Michaux expresses that in The Mining of Minerals and the Limits to Growth:
Current industrialization has a foundation in the continuous supply of natural resources” … Growth and expansion with no considered limits of any kind was the underlying paradigm.
This assertion is supported by research as the following diagram shows:
It goes without saying that this is not sustainable on a finite planet. To make matters worse, as more and more material input is needed, with diminishing resources of raw materials and low hanging fruit harvested, more and more energy is needed to mine the same, let alone more:
Undoubtedly, the continued material growth has an impact onto the environment. A popular way of expressing that impact is the I = P × A × T equation developed by Paul Ehrlich and John Holdern in the 1970ies:
The impact is the product of population, affluence and technology, or in the words of Tim Jackson in his book Prosperity Without Growth:
The so-called I-PAT equation tells us quite simply that the impact of human activity is the product of three factors: the size of the population, its level of affluence expressed as income per person; and a technology intensity factor which measures the impact associated with each dollar we spend.
This formula can be applied to the impact of many things such as natural resources or energy. With all factors being expressed as respective exponential functions and constant gains, this formula can be stated as:
Consequently, the evolution of the impact onto the environment depends on the sum of the exponential growth factors: population, affluence and technology intensity (proportional to the inverse of efficiency). If the impact was to be maintained constant, then the sum has to be zero. For instance, a decrease in the technology intensity factor (increase of of efficiency) has to compensate both population growth and increasing affluence.
If there was a snag about the I-PAT concept, then perhaps the regeneration factor of the planet would have to be accounted for, too.
Economic Growth and Material Steady State
Where does that leave us? Despite the current exponential growth of material resources (as shown before), negative feedback mechanisms such as an exponential growth in energy expenditure to mine natural resources will kick in at some point as well as some increase in efficiency. Then it can be expected or hoped for that material growth will level off and the environmental impact reaches some steady state. All resources that can be mined have been mined and all matter is subject to a circular economy. There is a constant mass in circulation, a material steady state would have been reached.
Despite being a system in a material steady state non-material economic growth can still happen. That concept is not new: John Stuart Mill reflected already in 1848 on the “stationary state of population and capital”, and later, Herman Daly, made a case for a “steady state economy” by stating:
… if we are to remain within ecological scale, there must be a constant stock of capital assets, capable of being maintained by a rate of material throughput that always lies within the regenerative capacities of the ecosystem.
Given the aforementioned I-PAT equation using exponential factors, it is not inconceivable to reconcile economic growth and a material steady state. There can be an increase in affluence, as long as it is matched by an increase in efficiency while the total mass of resources in circulation is constant. This sounds much like the concept of life on a spaceship.
Prosperity does have a material dimension, the material substrate sophisticated human life is built upon. Despite the concept of a circulating mass or a given fixed amount of matter, economic growth can still happen if the circulation frequency increases: more material can be transformed in a given time frame. Hence, even if the circulating mass is constant the throughput can still increase, like the transported mass on a circular conveyor belt being constant but the conveyor belt running faster. More stuff in circulation needs more energy, mostly proportional to the throughput as any transformation needs energy.
The energy fuelling all circular processes on earth will have to come from somewhere while still having to be renewable. Otherwise, the planet will warm up as energy eventually converts to heat. In order to maintain a thermal equilibrium more heat will have to be radiated which can only happen at higher surface temperature. Consequently, solar energy is the sole sustainable input and will limit the amount of energy or power is available in the end. Fortunately, the amount of energy in solar irradiation is enormous.
Prosperity on Spaceship Earth
There is an ongoing discussion on whether climate change has to be addressed through de-growth, i.e. reduction of economic/material growth, or simply by increasing efficiency and more technology. Given the aforementioned I-PAT model, both are not mutually exclusive but complementary in a two-pronged approach:
- reduce the material foot print for affluence, de-growth in material terms, i.e. counter-consumerism, less “stuff” and focus on non-material activities
(services, care, craft, creativity, culture & arts); - efficiency and technology, reduce the intensity factor and increase efficiency of processes and products which are often means only
(increase of energy and resource productivity).
Similar principles to the spaceship design should be applied to economic endeavours on planet Earth: minimalism, longevity, recycling, efficiency and frugality, in the words Elise Boulding:
Frugality is one of the most beautiful and joyful words in the English language, and yet one that we are culturally cut off from the understanding and enjoying. The consumption society has made us feel that happiness lies in having things, and has failed to teach us that happiness of not having things.
Post Scriptum
- There is one very important concept in physics and engineering: energy. Energy can be seen as the quantification of a physical property that is related to the potential of work or transformation. It comes in many shapes: mechanical energy as kinetic energy in a moving mass, or potential energy as an elevated mass; electrical energy as current in a coil or an electrical charge in a capacitor; thermal energy as heat at a certain temperature above the surrounding; chemical energy in the bonds of elements and compounds. The most important aspect is the conservation of energy in a system. Energy is not created nor destroyed, but only transformed, also known the First Law of Thermodynamics.
- The second, equally important concept in physics and engineering: entropy. While most forms of energy can and will eventually be transformed into heat, not all heat can be transformed back into higher forms of energy such as mechanical or electrical energy. For instance, friction will slow a moving mass down and convert its kinetic energy into heat; but heat on its own won’t make the object move. Or, both hot tea and cold beer each in a glass will eventually assume the same common temperature. In other words, there is a natural tendency for matter to assume the most stable state possible: a uniform temperature, the lowest altitude, or the lowest possible energy in a chemical compound. Entropy can be seen as the quantification for irreversibility of physical processes. While energy is always conserved entropy increases in a closed system, known as the Second Law of Thermodynamics.
