Everything that human civilization has ever done has been powered by energy taken from the Earth and our environment. But that harvest is not without consequences, from our burgeoning population, to the carbon dioxide emissions warming our climate. Those changes are dramatic and long-lasting enough that some scientists think we’re at the dawn of the Anthropocene, a proposed new geological epoch defined by our large-scale impact on the planet. It’s an intimidating thought—but there’s a possibility that we aren’t the only lifeforms in the universe to face down their world-altering behavior.
In a new paper,published in the journal Astrobiology astrophysicist Adam Frank proposes that an Anthropocene might be “a generic feature of any planet evolving a species that intensively harvests resources for the development of a technological civilization.” In other words, when you get advanced enough, and start consuming resources and energy at a fast enough clip you necessarily start to change your home planet on a global scale.
A model civilization
Frank borrowed from population ecology to devise models that represent the relationship between a civilization and its planet, using mathematical equations similar to those used by anthropologists to represent the rise and fall of ancient civilizations, like the one on Easter Island. Here’s the idea: A civilization takes a resource from its planet (or island), and that resource allows the civilization to grow; but a growing population, combined with harvesting and consuming that resource, also has an impact on the civilization’s home, diminishing its ability to sustain the civilization at large scale.
But this isn’t a mindless feedback loop. By varying the civilization’s foresight and speed of action, and the planet’s sensitivity to the civilization’s stressors, Frank was able to sketch out a range of possible outcomes on hypothetical planets.
He found that as he tweaked the variables—how quickly the civilization switched to a lower-impact resource, how sensitive the planet was to abuse—the model produced a wide range of outcomes. Sometimes a gradual die-off, sometimes a brutal collapse. Sometimes the civilization found balance, in what Frank calls “the soft landing.” But most surprising, he said, was when collapse came even long after switching to the lower-impact resource. The graph of this outcome looks for a long time like a soft landing, with civilization and planet continuing on at what looks like a steady level of health. But the sense of balance is misleading—there’s no permanent recovery for a planet like that, which has already been pushed too far past the tipping point of sustainability. Such a system isn’t in balance—it’s just holding for a long moment before it falls apart.
Frank hopes that these very simple models will be just the starting point for ongoing research. He says, “The next step is to actually put in a climate model—a real, honest to god climate model. I want to run this for lots and lots of different cases of planets. Planets that are closer [to their stars] in the habitable zone, planets that are further out in the habitable zone, planets that have different types of atmospheric compositions.” He hopes that by assembling a diverse set of possibilities we’ll have a rich galactic context within which to see our own struggles on Earth.
Frank contends that thinking of ourselves as just one of many civilizations who have hit the “Anthropocene bottleneck” is a crucial change of perspective. Because it allows us to think about the ways through the bottleneck, and to imagine them in large enough quantity that patterns—and possibilities—begin to emerge.
For Frank, this part of a larger research project, which he calls the Astrobiology of the Anthropocene. He believes that our struggles with sustainability can be contextualized through astrobiology, that the study of the relationships between planets, life, and civilizations can provide a useful lens for examining and understanding our home.
He makes this project explicit—and something of a manifesto—in his new book, Light of the Stars. In it, Frank draws on astronomical discoveries throughout history to put our world (and others) in context.
From the SETI pioneer Frank Drake’s work he pulls a conceptual framework for imagining the abundance of life on other worlds; from probes sent to Venus and Mars, an understanding of planets as guided by universal rules of climate, geology, and chemistry; from James Lovelock and Lynn Margulis’s Gaia Theory, the understanding of a planet as a system of interrelated biological, chemical, and physical systems; and from Carl Sagan, a crucial metaphor: of the Earth as a cosmic teenager.
As Frank puts it, “We have the keys to the planet, we're kind of stoned on fossil fuels, and the question is whether or not we can mature.”
Because we are cosmic teenagers, Frank says, we’re stuck in a global mope, looking at how we’ve ruined the Earth and telling ourselves that we suck. But he hopes that we can be snapped out of it—we aren’t the first planet to go through this, and we’re not the first civilization to have to step up to the responsibility of having our own future in our hands.
Frank doesn’t see that as hypothetical, either. One of his previous papers in The Astrobiology of the Anthropocene was a calculation of what he calls “the pessimism line,” a measure of just how rare technological civilizations would have to be for ours to be the first. He found that in order for our civilization to be the first in the galaxy, the odds of a technological civilization evolving on a habitable planet would have to be less than 10-22, or one in ten billion trillion.
That is very, very low.
If the odds are any better than that, then we’re not the first. Frank hopes this research can be part of a new story that we tell ourselves, a new way of understanding our future. He writes in Light of the Stars, “Try to get a teenager to change his or her driving behavior only by quoting statistics about traffic fatalities, and you’re likely to be met with a blank stare.” So the science has to tell a more compelling story.
Perhaps the most powerful take-away from Frank’s story is that if it is an inherent feature of technological civilizations to put stress on our planets with resource use, and if every civilization faces its own Anthropocene, then we can cut the self-loathing out of the way we think about climate change. We’re not inherently bad or evil or lazy or stupid for ending up where we are. We’re just another manifestation of life, which itself just another manifestation of planets. And, like those who came before—whether they’re hypothetical or real—we’ve come to the point when we have to figure our business out.
Christie Manning, assistant professor of environmental studies and psychology at Macalester College, who was not involved in this research, says one strength of Frank’s approach is that it doesn’t rest on fear of a catastrophic future. Manning, who studies how people respond to information about climate change says, “If you want to encourage action, fear is often counterproductive. It narrows our thinking (so we are less creative in our solutions) and makes us less willing to work with those who are different from us.”
At the same time, she says, it’s important that the story we tell is still emotionally rich. “I see a risk that Frank's framework could remove too much emotion and make our environmental situation seem psychologically distant rather than urgent and pressing. Research confirms that an emotional reaction of some kind is essential in prompting behavior, such as supporting climate policy. We need to care, to feel worried or concerned, and to feel responsible. These feelings push us toward action.”
Frank agrees that we’re at a point where the decisions we make today will have serious consequences for our future. But he wants humanity to stop seeing ourselves as a plague on the pristine Earth. As as environmental historian William Cronon wrote in his essay, “The Trouble With Wilderness,” the idea of a pristine, pre-human Earth is a fallacy, built out of nostalgia and infatuation with the sublime. We are not killing the Earth and, Frank says, it’s also not our job to save it.
Whatever choices humanity makes, whatever we do or don’t do to curb climate change, the Earth will be fine. Life on Earth will continue. Species that go extinct will be replaced. A previous mass extinction, Frank points out, is how mammals came to prominence in the biosphere at all.
“Of course,” he said, “that doesn't give us license to do whatever we want. The fundamental fact is that the Earth will be changed by us. That doesn't mean it's going to be worse, that just means it's going to be different. What we really care about is being part of it.”