We frequently define words by explaining what they are not. Coldness is the absence of heat. An object in motion cannot be stationary. If I feel relaxed, then I am free of worries. Antonyms allow us to relate words to one another by providing a point of reference. This works well for words with concrete properties. However, as words become more conceptual, it often becomes more difficult to supply a binary opposite.
By this logic, “nature” might seem like the ultimate unpaired word. In fact, the word is difficult to define in itself. How do you distill the concept of nature, the simultaneous container for and creator of the entire physical world, into words? Word-crafters have tried throughout time to capture the significance and grandeur of nature. Blaise Pascal imagined nature to be “an infinite sphere of which the center is everywhere and the circumference nowhere”. Ralph Waldo Emerson more abstractly illustrated it as “a mutable cloud which is always and never the same”. Emily Dickinson uttered, “Nature does not knock, and yet does not intrude”. Rather than assigning a textbook definition to the word “nature”, we rely on literary devices, hoping that they may do justice to its colossal meaning.
Yet, as difficult as it may be to explicitly define “nature”, most people have no trouble identifying its opposite. To help us make sense of nature, we juxtapose it with man. We tell ourselves that nature excludes man, just as fast negates slow, and day precludes night. “It appears to be a law that you cannot have a deep sympathy with both man and nature”, beheld Henry David Thoreau. We associate nature with bucolic landscapes, pristine oceans, and the plants and animals inhabiting them. These images have no place for humans, and the structures, objects, and technologies we create. We’ve decoupled nature from anything human, pinning the natural environment against the built environment.
The problem with this definition of nature is that it severs our sense of accountability to the natural world. If we are not members of nature’s kingdom, then we do not have to answer to its edicts. We have a diminished duty to care for it. Furthermore, placing ourselves outside of nature’s realm opens up the possibility for us to dominate it. Instead of viewing ourselves as a part of nature, we view nature as our toolbox. This definition of nature, by excluding all things human, allows us to fancy ourselves masters of nature, whose duty is to contain nature’s insubordination, and to prevent it from spinning wildly out of control.
Indeed, when we imagine the world without humans, apocalyptic scenes might unfold in our minds. Tall grasses and vines overtake our painstakingly manicured lawns, creeping insidiously over our fences. Geometric neighborhoods revert back to thick, boisterous deciduous forest. Refrigerators become breeding grounds for bacteria – the milks curdle; the vegetables entertain new molds and fungi. Insects, squirrels, deer, and coyote ravage our neat rows of crops. These scenes paint a picture of savage disorder. They suggest that humans restrain nature’s propensity towards chaos.
However, if we extrapolate a bit further, we’d realize that, without us, nature would simply adjust and re-establish equilibrium. This overlaying of order by chaos, if humans suddenly ceased to exist, would reflect our insignificance. It would relay that we actually occupy only a tiny fraction of nature’s tapestry. In fact, if we were to disappear tomorrow, all of us – pack up our bags and leave for another planet – nature would simply forget us, swallowing the spaces we have left, engulfing the emptiness. Within the decay of our constructed environments, we would be forgotten.
Thus, I call for a new definition of nature – one that does not simply describe nature as the antithesis to human civilization; that recognizes that nature operates at a scale much larger than that of the human domain; and that pays tribute to nature’s ability to maintain universal equilibrium. I believe that the essence of nature is feedbacks –feedbacks that orchestrate the synchronization of our planet, and render everything on Earth interdependent on everything else. These feedbacks are what actually keep nature from spinning wildly out of control. They lend our planet a stoic resilience. Nature is constant in its response to change, steadily establishing and reestablishing equilibrium. It does so through a network of feedback mechanisms created by the interactions between elements, microbes, plants, and animals.
The Earth relies on feedback cycles to keep the planet at a habitable state. For instance, nature employs multiple mechanisms to maintain temperatures amenable to life. One such mechanism employs a negative feedback loop that operates on geological timescales. When the planet warms, rates of evaporation increase, triggering more rainfall. As rain forms, it dissolves CO2 from the atmosphere. This weak acid rains down from the sky, and weathers rocks on land, releasing calcium and carbonate ions. These ions eventually travel to the oceans, where organisms use them to make shells. The entire cycle removes CO2 from the atmosphere, where it causes warming through the greenhouse effect, and sequesters it in the ocean, thereby causing the planet to cool down. Negative feedbacks such as this one prevent nature from swinging too far in one direction – and, in the process, allow life on Earth to continue thriving.
Life itself also relies on an interconnected web of feedbacks to ensure order. On a micro level, biotic communities seem to be governed by conflict – organisms take advantage of, compete with, and prey on one another, each beast protesting the inclinations of the others. However, on a macro level, this chaos actually sustains a steadfast functionality, and out of interspecies confrontations emerges a harmony that allows all living things to co-exist and indirectly support one another. These interspecies interactions seem to follow Newton’s law of reciprocal motion. A force in one direction is met with a force in the opposite direction. Each reactive force keeps the other at bay, leaving nothing unchecked. Foxes prey on wildly copulating rabbits, placing a ceiling on the species’ population growth. Elephants stomp around the African savanna, suppressing the trees’ propensities to take over and turn grassland into forest. Earth is always at a makeshift steady state, an equilibrium that relies on local skirmishes on the ground, in the water, and across the vast seas.
Negative geological and ecological feedback cycles cancel perturbations and assaults to nature’s norm; they always tend towards bringing Earth back to a steady equilibrium. We owe Earth’s ability to sustain life to these negative feedbacks. However, if only negative feedbacks existed, nature would never change, always returning to the same place time and again. Thus, positive feedback cycles provide opportunities for directional change. They allow nature to evolve, and to establish new states of equilibrium.
For example, although Earth has long-term feedback mechanisms to regulate its temperature, there have been drastic peaks and valleys in temperature over relatively short periods of time. In fact, geologists believe that our planet has become completely frozen at least once throughout history. Known as Snowball earth, this phenomenon likely occurred as a result of positive feedback loops that magnified the Earth’s albedo. The exact trigger for Snowball Earth is disputed, but it may have been a powerful volcanic eruption, variation in the Earth’s orbit, or a change in solar radiation. Regardless of its source, this initial cooling increased the area of ice and snow cover on the Earth’s surface. As in a set of dominoes, this first disruption would have set off a chain of cooling events. Higher ice and snow coverage would have reflected more solar energy back into space, causing the Earth to cool further, and ice and snow to spread even more. Thus, positive feedbacks amplify directional changes, such as the runaway cooling that occurred during Snowball Earth.
Eventually, nature tends to return to equilibrium after positive feedback events. In the case of Snowball Earth, enough atmospheric carbon dioxide accumulated in the atmosphere to melt the snow and ice cover. Some scientists believe that this melting was associated with the rapid evolution of new life forms. Indeed, the unique evolutionary pressures from extreme events caused by positive feedbacks, such as Snowball Earth, can drive extraordinary surges in diversification that would not have otherwise occurred if Earth persistently remained at a constant state. Thus, in addition to maintaining balance through negative feedbacks, nature grows and evolves through positive feedbacks.
The beauty of viewing nature as an interwoven network of feedbacks is that this definition inherently includes humans as well. Our human activities do not exist in a vacuum outside of nature; rather, they are a part of the world around us. In fact, using another definition of the word, one could even argue that our need to build, create, and carefully appropriate resources is ingrained in our human “nature”. Our innate drive to tailor our surroundings to our advantage has allowed us to master the evolutionary game. We’ve carved natural habitats into linear patterns that make sense to us, driven out native species, perfected the mass production of food, and developed drugs to fight disease.
Yet, as humans, we are not exempt from nature’s checks and balances. When we re-fashion the world around us, our plans rarely go according to plan. Irrigation canals built around the Aral Sea have reduced a formerly vast expanse of water to a barren wasteland of salt and chemicals. The destruction of coral reefs for prawn farms and seaside resorts amplifies the destructive force of tsunamis. Our antibiotics breed microbes that are experts at evading any new drugs we throw at them.
These feedbacks remind us that humans are no more a part of the natural world than any bacteria, plant, or animal. We are members of nature’s giant network, giving and taking as any other organism does. And while it may seem to us that humans temper nature’s disarray, we actually participate in the order that nature creates for itself. The small-scale mayhem we observe, in fact, holds everything in place.
Eliminating the dichotomy between humans and nature might allow us to re-think our relationship to it. If we begin to see ourselves as part of nature, rather than exempt from it, then we would understand that it behooves us to care for it, rather than exploit it. We serve not only the human community, but also the community encompassing all of Earth’s organisms and landscapes. It is when we regard ourselves separately from nature that we think we can claim its resources as our own commodities. Instead, we should view our existence and human tendencies as part of nature, and therefore subject to nature’s matrix of feedbacks. Our actions prompt responses that can propagate across the continents, through the animal kingdom, or into the soil horizons of the Earth.
Our interdependence on and connectedness with all of nature calls upon us, as humans, to expand our sphere of accountability to the entire natural world. We might begin to accomplish this task by reframing our definition of nature. Nature – a system that grows, evolves, and finds balance through feedbacks. These feedbacks allow nature to establish equilibrium through tug-of-wars, create unity out of discord, and achieve progress from adversity, on a scale that transcends all others.