Pick up any newspaper or magazine that writes about society, the economy, the environment, or listen to policy makers on the same. The words “sustainability” and “resilience” will surely be there as themselves or in their adjectival forms. This very journal has the former in its title. Not far behind are a plethora of other terms. We wish a healthy economy, a harmonious society, and environments should be resilient and our use of them sustainable.
To understand these expressions, the first stop has be the dictionary. I admit to owning three copies of the Oxford English Dictionary. There’s one at home, one at work, and one online since even my miniaturised printed ones with the supplied magnifying glasses are too heavy to cary far. “Resilience” is simple enough. OED has recorded it meaning “rebounding” since the seventeenth century. The other terms are also venerable.
So far so good. The complication is when the terms become normative. That is, resilience is not just a property, but some goal we wish to achieve. Why stop with just one? Societies develop — in the sense people have more money, suffer lower rates of childhood mortality, and so on. “Development” is often normative, and “sustainable development” a double dose of aspirations.
“What exactly do you mean when you propose that humanity wants sustainable, resilient ecosystems?” I want to ask the plenary speaker to a conference I'm attending. I wait, knowing that “sustainable development” will soon be invoked as the solution to all environmental ills and “a heathy, harmonious society” its crowning achievement. The audience applauds. It would be churlish to ask why the speaker presented no numbers.
My gentler self understands that human society and the natural world are complex, dynamic things that tempt us to summarise with synthetic terms. Ecologists have long written about “stability,” yearning for a measure that captures the dynamics of the multiple species and processes we study. Might there be divine relationships — “complexity begets stability” — that provide unifying Laws of Nature? Alas, if you insist on ascribing a sex to her, then Mother Nature is a difficult lady. Stability in her nature means many things — resilience and sustainability among them — complexity several things, and all can be applied to different levels of ecological organisation. Pick one from each pile and it’s a coin toss as to whether one increases as the other does1.
What resilience, sustainability, and other terms mean, matters. José Montoya, Ian Donohue, and Michel Loreau, and I argue that careless use is unhelpful2. OED is there to help, but above all, terms need measurement. It forces our being explicit about how we measure, what we measure, and over how long we measure. Talk is cheap, measurements hard. Without them, we have no way to compare what we are doing for good or ill to the natural world.
1Pimm, S. L. 1984. The complexity and stability of ecosystems. Nature 307:321–326.
2Pimm, S.L., Donohue, I., Montoya, J. M., and M. Loreau 2019. Measuring resilience is essential to understand it. Nature Sustainability, 2, 895-897.
Stuart Pimm holds the Doris Duke Chair of Conservation at the Nicholas School, Duke University, and is President of Saving Nature www.savingnature.com. Saving Nature works to fund land restoration by local partners in tropical, biodiverse communities that reconnect isolated habitat fragments. It is committed to transparent conservation actions, monitoring progress with remote sensing, drone flights, and camera trapping.