Earth in Human Hands Read online

  Our oblivious stumbling into ecological and climate danger could be just a phase, characterized by inadvertent, clumsy human interaction with planetary systems. There is another way to do this. I’ll describe some examples of a more thoughtful mode of engagement that, while still in its infancy, is clearly something we are capable of. I believe the true Anthropocene, what I call the “mature Anthropocene,” characterized by intentional, deliberate interactions with the planet, is something that should be welcomed. Though it is only in its infancy, it can already be glimpsed. Awareness of ourselves as agents of geological change, once propagated and integrated, could provide us with the capacity to avoid doom and to take our future into our own hands.

  Here I’ve been speaking of the human species as one thing, and human civilization as one thing, when obviously both are a great many things with diverse and complex histories. Yet since the problems we face are global, and to some degree our solutions must be as well, this begs the question of who we are really talking about when in this context we say “we.” This is a dilemma I will revisit.

  The planetary perspective provides a kind of out of body experience for us—hovering in orbit and watching ourselves sleepwalk through a slow disaster of our own making. Now, can this experience help us to shake ourselves awake? For virtually all of its history Earth has evolved without us, and we have always seen ourselves as autonomous actors on a passive planetary backdrop. But now we are beginning to see that our futures—those of humanity and of planet Earth—are tightly conjoined. If human civilization is to persist and thrive we will need a completely different view of our planet, and of ourselves, in which we acknowledge both our deep dependence and our increasing influence. We need visions of a future in which we have applied our infinite creativity to the task of living on a finite world, where we have embraced our role, become comfortable and proficient as planet-shapers, and learned to use our technological skills to enhance the survival prospects not just of humanity but of all life on Earth. My name for this vision is Terra Sapiens, or “Wise Earth.”

  A recent scientific breakthrough enriches this story: the exoplanet revolution. As we long suspected and have now confirmed, this universe is full of planets, orbiting nearly every star. It is now very close to inconceivable that we could be the only life, and only technological intelligence, in the universe. An interplanetary perspective on Earth’s current dilemmas incites us to wonder whether parallel dramas may have unfolded on distant worlds. Do other planets also grow inventive brains that end up causing themselves problems? Do other species develop technology and build civilizations that create dangerous instabilities on their planets? How do they cope? Do planetary biospheres become self-aware? The Anthropocene leads us to a new way of looking at SETI—the search for extraterrestrial intelligence—which in turn illuminates changing notions about ourselves, how we fit into our planet, and what kind of future we dare imagine.

  One hundred million years from now, what will our time have been? A brief climate spasm that Earth shrugged off and largely forgot, leaving a thin layer infused with bizarre plastic objects? Or the beginning of a lasting new phase when the biosphere finally woke up and adjusted its grip on the planet?

  In 1758, when Carl Linnaeus—the Swedish botanist who invented modern biological taxonomy and classification—needed a name for the human species, one that distinguished us from others in the genus Homo, he called us Homo sapiens, or “wise apes.” Is this a good name for us? Or was this wishful thinking? Linnaeus saw that we were good at problem-solving, and he was himself an exemplar of the scientific revolution in which the human intellect was rapidly teasing apart the mysteries of the universe like no other animal could. We had learned to “tame nature” in so many ways. We had reason to be proud of ourselves. But at that time Linnaeus could scarcely have conceived the kind of wisdom that we need now. We’ve been so successful at solving problems of survival in many different local environments that we’ve exponentially increased our numbers and global influence. We’ve spread ourselves so widely around the planet that we’re now confronting a new environmental factor that may not be so easy for us to tame: ourselves.

  What does wisdom mean for a species with the power to change its home planet, affecting the fortunes and futures not only of themselves but of all life? Certainly it requires us to comprehend our role in the physical workings of the planet and to act in ways that are not obviously self-destructive. It is strange that geology and planetary science, investigations we began out of simple curiosity, have now become crucial forms of self-knowledge. Although science has helped us stumble into the Anthropocene trap, it also provides the tools with which, armed with wisdom, we could spring ourselves from it.

  Can we live up to our name and create a wisely managed Earth? We have no choice but to try, because events we have already, unwittingly, set in motion are leading us inevitably toward a branching point between calamity and wisdom. Yet once we overcome the fear and embrace this new reality, then thrilling new future possibilities for our planet and ourselves open up before us.

  1

  LISTENING TO THE PLANETS

  And you may ask yourself, well, how did I get here?

  —Talking Heads, “Once in a Lifetime”

  Sidewalk Wisdom

  For the past two years I’ve been living in a carriage house on Capitol Hill, seven minutes’ walk from my office in the Library of Congress. It’s a leafy, gentrified neighborhood of colorfully painted restored Victorian brick houses, and on sunny weekend days you can score all manner of quality household items on the wide cobbled sidewalks, choice stuff left free for the taking by residents too generous or busy to dispose of them otherwise. The boxes of books that appear weekly along East Capitol Street (a stack of used baby manuals, a pile of tomes on population dynamics from a year at an NGO, discarded cookbooks from someone’s vegan phase) provide irresistible glimpses of the lives in these handsome Washington homes, and occasional serendipitous enlightenment.

  Once, on Seventh Street, I spotted a sky-blue book lying on the redbrick curb. Upon approach, I saw it was Anatomy of the Sacred: An Introduction to Religion (sixth edition), by James C. Livingston, conspicuously folded open to a specific page. A message of some sort? I brushed off the dirt and read:

  Whatever the cause of our unease and strife, few thoughtful persons would deny that we humans have, over the millennia, sensed a tragic flaw, a falling short of our potential, a missing the mark of life as it was meant to be or should be. Something, we feel, is “out of joint.”

  “How true,” I thought. “What is it about humanity?”

  The very next day, I found a true treasure, containing one possible answer. In a carton of mostly forgettable, fluffy self-help books, out-of-date travel guides, and other discards, an old textbook caught my eye: Psychology Today: An Introduction (second edition, 1972). Reflexively I glanced at the list of contributors on the inside cover. At the very bottom, it read, “Chapter Introductions by Isaac Asimov.” Say what? Are you kidding me? I took that one home. Each of the thirty-four chapters is preceded by a short, informal essay by the great science-fiction maestro. The writing is playful, irreverent, personal, and insightful. Asimov introduces each topic of human psychology by riffing on free will, the nature of consciousness, intelligence, and morality, and his famous “laws of robotics.” These constituted Asimov’s science-fictional device for ensuring that conscious robots could not behave dangerously. If we invent powerful, capable machines with smarts, awareness, and autonomy, we might, he imagined, build into the very fabric of their minds inviolable ethical precepts to be obedient, cooperative, and altruistic. Asimov was prescient. Today his laws come up frequently in discussions about how we can keep artificial intelligence from becoming threatening. Yet his robots were also foils for us and our troubled relationship with our own runaway cleverness. His stories explored the conflicts inherent in complex moral minds, whether evolved or engineered with technologically amplified capacities.

  In one
of these microessays, Asimov summarizes the way in which life has organized itself into a hierarchy of structures, with organisms at each level being built from collectives of simpler organisms. He looks at where we ourselves fit into this scale-spectrum of complexity. First there are the viruses, which are almost too simple to be alive. They seem more like molecules than creatures, each not much more than an encapsulated coil of RNA or DNA. The ultimate freeloaders, they hijack the machinery of more fully developed living cells in order to function. Then there are the simplest, undifferentiated cells, the bacteria. More complex cells are made up of various component parts, each of which is itself rather like one of those simple bacterial cells. These complex cells can exist as free-floating individuals or can be loosely bound with others in various colonial arrangements. Finally, as Asimov describes,

  cells can drown their individuality and abandon their free-living abilities in order to form a multicellular organism, which may be as simple as a flatworm, or as complicated as a giant sequoia, a whale or a man.

  He points out, however, that the hierarchy does not end there. A multicellular organism by itself is often useless. It needs others to survive and propagate. All but the simplest reproduce sexually. Many are dependent for their survival on more complex social arrangements: a herd, a school, a flock, or, in our case, a tribe or society. Some (for example, the social insects) have such tight interdependence with other individuals that they form what might be called superorganisms, and in those cases, it may legitimately be questioned whether individuality resides in the organism or the hive.

  Just as we individual humans are multicellular organisms, each an exquisite arrangement of forty trillion cells, with the whole being greater than the sum of its parts, so we cannot fully manifest our humanity, or survive for long, without joining together to form larger associations. Asimov sums it up:

  As individual multicellular organisms, however, we would be less willing to agree that a complex society or state is greater than the sum of the individual organisms making it up. We would be less ready to judge that it is a cheap price to give up our individualism to become part of a society.

  Yet the tug is there. It is as though we are at some stage of evolution between the multicellular and the multiorganismic.

  It strikes me that the tension Asimov identifies here is at the heart of many of our political, economic, spiritual, and environmental struggles. We are trying to work out this question of how to thrive as individuals who also cannot exist without some larger cooperative order. Ever since the time most of us gave up hunting and gathering in the clans with which we roamed for almost all human history, and instead domesticated into villages, cities, and nations, we’ve been trying to figure out how to organize ourselves. Our initial success at banding together in groups to solve problems and invent technologies allowed us to change our world without knowing it. Now that we see what we’ve done, we face new challenges that require us to develop new cultural technologies, new civilizational solutions that allow for coherent action among much larger groupings. Yet we’re not insects, and we cannot subsume ourselves to the hive. We need our individual freedom and creativity, but now, as never before, we are confronted with the need to make smart, coherent collective technological choices on a global scale in order to survive. It would not surprise me one bit if someday we learned that intelligent species on other planets also have had to struggle with some version of this same evolutionary dilemma.

  This tension between our individual and collective selves is evident in the trouble we’re having grasping the depth of our role in the changes now enveloping our planet. Somehow our minds and our inventions, our cognitive systems and their material extensions, have become part of the workings of this world. We got here because we are so good at communicating, cooperating, inventing, and making plans. But we never planned for this.

  What a strange journey this planet has been on. Born as an inanimate orb, it hatched and became animated, with life soon spreading everywhere around and through it, and embedded deeply in its mechanisms. Later, life generated mind, which now is also becoming integral to the way the world works. What a thing for a planet to grow brains, sprout opposable thumbs, build machines, and start to rework itself. If we worry about our own creations getting out of hand and running roughshod, how do you think the planet, if it feels anything, feels about us? Well, this planet does feel, because we feel—and as the unwitting agents of this latest transformation, discovering it already in progress, we feel confused, like sleepwalkers awakening to find ourselves in the middle of rewiring our home without a manual.

  How did we get here?

  A Curious Anti-Accretion

  The birth of Earth was fast and rough. In thirty million years, tops, nearly every bit of our planet came crashing down from space, falling together in a violent coalescence we call accretion.

  In that same brief flurry, all the planets of our solar system self-assembled, congealing out of the dusty, spinning disk swaddling the infant Sun. In the surrounding blackness the swirling hot mess radiated and cooled. The temperature plummeted, and it started to snow. Sticky flakes of ice, rock, and metal clumped together into dirty snowballs. These grew slowly and randomly, until they were big enough to feel one another’s presence. With the encouragement of gravity, the growth quickened. Pebbles gathered into cobbles, then boulders, then “planetesimals,” little planets up to a thousand kilometers across. As these more massive bodies threw their weight around, the smash-ups gathered speed. Ever more furious collisions annihilated most planetary contenders and added their remains to the few survivors. Soon only a handful of new worlds were left, traumatized, orbiting the Sun amid a dwindling swarm of leftover debris.

  With the accretionary scrum seemingly complete, four rocky worlds remained in the “habitable zone,” the band of space favorable to surface water, where the Sun is close enough to melt ice but far enough away not to boil oceans. Of these final four, two were Venus-size and two Mars-size. Yet the orbits were not entirely settled, and there was still to be one very nasty encounter. With a furious, glancing blow, one of the smaller, Mars-size orbs smashed into one of the larger, Venus-size ones. Earth was made in this last apocalyptic collision, which spat an incandescent shower of melted and vaporized rock into an orbiting ring of fire that soon condensed into our freakishly large and close moon. After this final calamity, there remained Venus, Earth, and Mars, three newborn planets where oceans might gather and linger.

  Largely molten from their fiery formation, thoroughly pocked with craters, and blanketed with hot steam, these newborn sibling worlds began to solidify and cool. The inner solar system was largely cleared of planet-forming bodies, but for another half billion years a diminishing fusillade of late hits would randomly trigger relapses to the primordial, molten state. In the calmer interregnums, various worldly activities commenced. Volcanoes erupted, storms raged, rivers flowed, and oceans filled. For a time, each of these three planets enjoyed a nearly identical childhood, with warm water lapping promising chemicals onto virgin rocks under the light of a faint young sun. Yet each would soon suffer a catastrophic change and head down its own unique path.

  And on this one world, the one in the middle with the looming oversized moon, organic molecules at play along the shores and vents of the new oceans stumbled into configurations that could replicate themselves. That replication changed everything. These carbon copies enabled chemical memory, so that good designs persisted and better ones prevailed. This planet enmeshed itself in an evolving sequence of changing forms, enfolding and transmuting the entire surface and atmosphere. This planet came to life.

  Eventually, four billion years later, again came something completely new: novel, stark, inorganic geometries began quickly remaking the surface. Suddenly, the nightside lit up in bright, spreading webs. Then there was a curious anti-accretion: some pieces of Earth, in seeming defiance of the laws of gravity, started launching themselves back out into the surrounding space from whence everything
had once quickly fallen.

  To Distant Climes

  I don’t know if space junkies are born or made, but my timing was good. Humans have, for fifty-three years at this writing, been launching small probes packed with instruments to investigate the other planets of our solar system. My life fits neatly into this new age of exploration. Space travel and planets were my obsessions from a very young age. Mariner 2, the first successful interplanetary spacecraft, arrived at Venus a week before I turned three, in December 1962. I don’t remember that, but I sure remember Uncle Carl (Sagan) showing up at our house when I was nine with glossy eight-by-tens of the new pictures sent back from Mars by Mariner 6 and 7, depicting abundant craters and none of the fabled canals. And I recall, from when I was eleven, the saga of Mariner 9, in which the true, haunting, faded glory of Mars was finally revealed.

  I don’t believe our destinies are written in the stars or planets, but these early exposures to interplanetary mysteries had a strong effect on me. Despite the occasional temptation to put aside scientific instruments for musical ones, I was irresistibly lured by the siren songs of Titan, Iapetus, and Aphrodite, and I followed them from childhood fixation to adult profession as a comparative planetologist. It is a young field, a by-product (more than we like to admit) of the Cold War development of launch vehicles that allowed us to start lobbing scientific instruments toward the other planets in the 1960s.