The conservation of change, what I sometimes call the Tao of Sustainability, is an idea that is built upon two ideas and an observation. If limits to growth are the first law of sustainability; the conservation of change may be the second.
The first idea is that sustainability is an organizational problem: a matter of how best to organize our societies and our cultural strategies such that people can be free to pursue their needs and goals without worrying about sustainability. The second idea is that sustainability is a movement, not a condition, to borrow the words of historian Arnold Toynbee. Sustainability is too often conflated with stability, with holding something constant, but the natural world needs not and does not conform with our industrially minded expectations for it (therein lies the problem).
The third piece, the observation, is related to this second idea: that stability in natural systems is an illusion, an artifact of scale. Where we see stability at one scale, it is invariably a product of change happening at other, usually smaller scales.
Increasingly, people talk about sustainability being a matter of learning to "mimic" natural systems. Lao Tzu calls this 'being the pattern of the world':
Be the Pattern of the World.
To be the Pattern of the World is
To move constantly in the path of Virtue
Without erring a single step,
And to return again to the Infinite.
Tao Teh Ching (28).
I propose that cycles are the pattern of the world, and cycles are indeed what many sustainability frameworks seek to emulate: a system of positive and negative feedback loops that create homeostasis at the desired spatial and temporal scale. Natural systems farming focuses on cycles at the level of the soil, the plot, and the field, for example.
As a scientist, I recognize that there must be physical laws that underlie this pattern, laws that we can use to enrich our understanding and practice of sustainability. Specifically, I hypothesize that the ubiquity of cycles is related to the second law of thermodynamics.
In Steps to an Ecology of Mind, anthropologist Gregory Bateson speculated that the second law of thermodynamics, the law of entropy, may be relevant to the scientific study of human behavior and culture. His argument is that social forms are organizational in nature, and whereas the first law of thermodynamics attends to material phenomena, the second law is about organization. Given my first premise above that sustainability is an organizational problem, I argue that the second law of thermodynamics is particularly relevant to the question of sustainability.
Entropy is often thought of as a measure of potential, disorder, or even chaos (though staunch physicists will chafe at this oversimplification). Another common sense way of thinking about entropy is as a measure of the probability--the probability that some particular organization of a system would happen at random. High levels of organization are low in entropy, and disorganized states are high in entropy. Consider a deck of cards sorted by suit: if the deck is thrown up in the air 52-pickup style and then summarily reshuffled, the probability of it returning to the sorted state is extremely low, whereas the probability of the deck being in some less "ordered" state is much, much higher.
In the most general sense, the second law of thermodynamics holds that in all closed systems entropy either stays the same or increases. The earth is not a closed system, however; we have the sun. Systems with energy input can keep their entropy low, but that doesn't mean that the second law is irrelevant. Rather in open systems, the second law of thermodynamics appears to be what make life possible. Open systems in an energy bath such as from the sun move towards increased energy transformation, or productivity in biological terms.
What does Entropy Mean for SUstainability?
Often, the environmental systems that we wish to sustain are often quite low in entropy: corn and soybean monocultures, and populations of tuna, salmon, and lobster, for example. Organizationally, these highly organized systems are low in entropy. They are very simple and this makes them vulnerable, like a sorted deck of cards. What's more, they are inefficient. Diverse ecosystems are always more productive than monocultures will be, which means that we are fighting the law of thermodynamics when we aim to sustain them. Not breaking it, of course; you can't break a physical law, but fighting it has its costs.
There is No Free Lunch
Simple, uniform systems are not as efficient, which means they require more resources to sustain, and those resources have to come from somewhere.
Ecologist Barry Commoner summed this concept up nicely with his fourth law of ecology: "there's no such thing as a free lunch." What he meant by this is that any exploitation of nature will inevitably involve the conversion of resources from useful to useless forms--an increase in entropy. If that change is not happening within the ecosystems we manage, it will happen through degradation elsewhere
I suggest that we must take this premise further--and propose that wherever we manage for uniformity in nature, for example of a fish population, we must be prepared to pay an entropic cost. Change must happen somewhere. We can choose to manage that change, steward it through cycles of growth and contraction, release and renewal, or we can allow that increased entropy to play out in terms of ecological degradation.
A "Gilded" Trap
Scientist Bob Steneck and his colleagues have explored the negative ecological and societal consequences of managing for stability without also managing change in the context of the Gulf of Maine lobster fishery. They don't explicitly reference the language of entropy and the conservation of change, but instead they use the language of resilience thinking, a framework of sustainability heuristics that derive from the conservation of change.
Lobster fisheries in Downeast Maine have long been considered sustainability success stories, and they are frequently invoked as a testament to the efficacy of bottom-up institutions for parametric (as opposed to quantitative) fisheries management. Practices like not harvesting reproducing females, and the maintenance of strictly delineated fishing territories, have sustained these lobster fisheries for decades and actually enhanced them to the point where, according to Steneck and colleagues, the Gulf of Maine ecosystem has become a veritable lobster monoculture.
Stability, in this case of a very abundant and uniform population of lobster, has come at the great cost of simplification of the surrounding food web; stability of lobster as a lucrative commodity has likewise resulted in simplification of the regional economy. Both, argue Steneck and colleagues, make the ecosystems and the communities that rely on them extremely vulnerable.
In other words, the Gulf of Maine lobster fishery is like the sorted deck of cards--incredibly low in entropy, which means that any disturbance has an extremely high probability of resulting in disorder, or in practical terms, pulling the rug out from beneath the uniformity and abundance on which local people and communities have come to rely.
Our contemporary industrial mindset and market-oriented goals work at cross purposes with the second law of thermodynamics, in that we are intolerant to the vagaries of natural variability and change. We seek ways to engineer nature into standardized and consistent systems of production rather than looking for ways to integrate our lives and lifestyles within the diverse and ever changing patterns of the world around us. Ecosystems are not machines, and if we treat them as machines, they will break.
The conservation of change principle helps us recognize the inherent costs of this philosophy, and suggests that a more sustainable approach is to relax our expectations regarding what ecosystems can provide in terms of stability. Rather than doing everything in our power to foster uniformity in a fishery or other resource, we can take control of entropy by embracing it, by embodying change in our own lives and livelihoods. I'm not saying that we need to become slaves to environmental variability and change, but that as in the quote that introduces this section, we simply need to learn to bend if we wish to remain whole.
I recently (12/30/2014) updated this page based on some insights from physicist Jeremy England's recent work exploring the relationship between life and the second law of thermodynamics in open systems. Now, I'm no chemical physicist, but I think his hypothesis strengthens the conservation of change theory, though I'll admit I'm still working out the details. What's important to know is that he's proposed that life is a natural outcome of the second law in open systems because in open systems will always move toward greater energy capture and dissipation. And as noted above, diverse systems are better at energy capture and dissipation than simple systems.