Light of the Stars

by Adam Frank

  Over time, the activity of the cyanobacteria dumped so much oxygen into the oceans and atmosphere that the entire planet was forced to respond. The geologic record shows evidence of early “whiffs” where atmospheric oxygen levels increased by small amounts. But by 2.5 billion years ago, the fix was in. Across just a few hundred million years, the concentration of atmospheric oxygen increased by a factor of a million.

  This was the Great Oxidation Event, or GOE. Ironically, the rise in oxygen was poison to the bulk of the life that existed at the time. Oxygen’s ability to bind with so many chemicals means it can quickly degrade the function of cells and kill them. But evolution figured out how to make lemonade out of lemons. It learned to work with oxygen’s juiced-up chemistry to create better, more energetic forms of life. Soon, creatures that breathed in oxygen had evolved. They used the element to power faster and more complex metabolisms.39 The big brain you’re using to read and comprehend these words would never have been possible without oxygen’s kick to evolution.

  By the end of the GOE, the anoxygenic phototrophs, once the planet’s masters, had been forced into oxygen-free warrens, learning how to live in places like the fetid sulfur pits of Yellowstone or even deep in our stomachs. In this way, the new oxygen-breathing forms of life inherited the open sea and open sky.

  The presence of oxygen in the atmosphere also allowed life to colonize the land en masse. Before the GOE, cell-damaging ultraviolet radiation from the Sun (the kind that gives you sunburn) streamed unremittingly through the atmosphere. Only in the oceans, below the surface, was life safe enough from UV light to form rich ecosystems. But with oxygen came the atmospheric ozone layer. Ozone is a gas, made up of molecules with three oxygen atoms, that forms high in the stratosphere. It’s a potent absorber of UV radiation. This ozone sunblock shield, which made the land safe for life, could not have formed without the rise in atmospheric oxygen.40

  So, what does the GOE, with all its power and reach, teach us about the Anthropocene? It demonstrates that life is not an afterthought in the planet’s evolution. It didn’t just show up on Earth and go along for the ride. The GOE makes it clear that, at an earlier point in Earth’s history, life fully and completely changed the course of planetary evolution. It shows us that what we are doing today in driving the Anthropocene is neither novel nor unprecedented. But it also tells us that changing the planet may not work out well for the specific forms of life that caused the change. The oxygen-producing (but non-oxygen-breathing) bacteria were forced off the Earth’s surface by their own activity in the GOE.

  So, from the GOE we gain insights that are themselves a turning of the wheel in humanity’s conception of itself and its place in the cosmos. We come to an idea that touches both the deepest levels of scientific consequence and the highest forms of mythic understanding. We come to the moment where the biosphere, and our place in it, can be fully imagined.

  THE BIOSPHERE BEGINS

  Scientists become famous for a lot of reasons. There are those like Einstein and Darwin whose visions shatter old ideas. Their names go on to live forever in the pantheon of genius. Then there are those like Carl Sagan and Stephen Hawking, both brilliant researchers, whose talents as writers allowed millions of non-scientists to understand the beauty and power of science. But how many people have ever heard of Vladimir Ivanovich Vernadsky? His name is far from a household word outside of his native Russia. But that obscurity is destined to change along with the planet.

  It was Vernadsky’s ideas—and their genius—that heralded a new scientific conception of life’s planetary context. As we enter more deeply into the Anthropocene, we will find Vernadsky already there, waiting for us to catch up with him.

  Vernadsky was born in 1863 in the St. Petersburg of Imperial Russia. His mother came from nobility; his father was a professor of political economy and statistics.41 Vernadsky’s parents were known for their devotion to democratic and humanistic ideals. From them, he inherited a fierce determination to live by those ideals, which was grafted onto a love of science. Across eighty-two years of wars, revolution, and acute political turmoil, Vernadsky did not waver in his devotion to scientific inquiry. And even at the greatest personal risk, he never wavered in working for the freedom to pursue scientific ideas, wherever they led.42

  Vernadsky began his scientific work in the chemical study of minerals. Traveling across Europe in the late 1800s, he was keen to apply the most modern methods of physics to the study of rocks. His goal was to bring precision tools to bear on questions about the planet’s history. But even as Vernadsky was committed to exacting empirical studies, he was always more than a specialist. Across his career, he struggled to see how the whole emerges from the narrower stories scientists can unlock from the parts.

  Russian scientist Vladimir Ivanovich Vernadsky.

  In this way, Vernadsky built a solid, data-driven foundation for a new field called geochemistry, which unpacked Earth’s history by examining the microscopic composition of its physical constituents. Then Vernadsky went further. It wasn’t just geology and chemistry that were linked. In his eyes, biology also had to be brought into the planet’s story at a fundamental level, so he initiated a second field: biogeochemistry.43

  Vernadsky was often critical of biologists for the way they treated “organisms as autonomous entities.” In his eyes, any individual species carried more than just an imprint of the environment within which it had evolved. Instead, the environment was shaped by the activity of life as a whole. As he put it, “An organism is involved with the environment to which it is [has] not only adapted but which is adapted to it as well.”

  This attention to both microscopic and macroscopic views led Vernadsky to his most important addition to the language of life in the context of its planetary host. Building on discussions with the Swiss geologist Eduard Suess, Vernadsky proposed that the study of the Earth would not be complete without understanding the central role of life as a planetary force. Earth, in his view, cannot be truly understood without understanding the dynamics of its biosphere.

  Living as we do after astronaut William Anders’s Earthrise, it’s hard to imagine that the biosphere could ever be a new or radical idea. But it was Vernadsky who gave the concept its scientific birth. It was Vernadsky who first clearly articulated what later scientists, studying everything from the Great Oxidation Event to modern climate change, would slowly—and with great effort—come to verify: Life was not just a patchy green scruff holding a tenuous position between rock and air; instead, it was a planetary power as important as volcanoes and tides. It was an active force shaping the complex multibillion-year history of the world. As Vernadsky wrote in 1926:

  The matter of the biosphere collects and redistributes solar energy, and converts it ultimately into free energy capable of doing work on Earth. . . . The radiations that pour upon the Earth cause the biosphere to take on properties unknown to lifeless planetary surfaces, and thus transform the face of the Earth.44

  Over the whole of his celebrated career, Vernadsky continued to modify and extended his concept of biosphere. Specifically, he saw it as a region—a shell—extending from below the Earth’s crust (the lithosphere) all the way to the edge of the atmosphere. Within this shell, the action of life dramatically changed flows of matter and energy.

  Most important for our own moment, Vernadsky saw that the world-shaping powers of life were both ancient and ongoing. “Adjusting gradually and slowly, life seized the biosphere,” he wrote. “This process is not yet over.”

  It’s the scale of his vision that makes Vernadsky so important to our story. Earth’s entry into the Anthropocene is, at one level, purely an issue of interacting planetary processes. Our entry into the Anthropocene, however, is different. For us, it’s also an issue of making meaning, of making sense of our place within the web of life that is also a force shaping the planet. Vernadsky envisioned a global view that achieved both. It was both scientific and mythic in scale, long before satellites and space missions coul
d make such a global view of Earth tangible.

  After his death in 1945, the limits of the Cold War meant it would take some time for Vernadsky’s radical view of life and its planetary reach to reach beyond Russia.45 But in time, Vernadsky’s vision did find its champions. As human culture was reshaped by its new space age, two scientists in particular would pick up Vernadsky’s biospheric vision and grow it into a full-fledged science.

  BIOSPHERE RISING

  James Lovelock was always the outsider’s insider. From the first radio set he cobbled together as a boy in England after World War I, Lovelock was an inventor of prodigious talent. Eventually, that talent drew governments and corporations to seek his help.

  During World War II, Lovelock’s degree in chemistry took him into medical research, where he invented everything from precision airflow meters for studying the common cold to specialized wax pencils that could write on wet test tubes. This talent as a “maker” would eventually bring a degree of independence as his inventions drew a steady income. In the 1950s, Lovelock designed a cheap, portable device for detecting minute amounts of chemical contaminants. The patent was so valuable it allowed him to pursue science on his own terms, independent of an academic or government affiliation. But governments were still keen to sign him on to their projects.46

  In 1961, Lovelock found himself at the same Jet Propulsion Laboratory in Pasadena, where Jack James and his team were exhausting themselves on the Mariner Venus mission. For Lovelock, the sprawling campus had the look of “a hasty airport with prefabricated cabins dotted over the hillside.” 47 JPL had paid for his trip to its nascent campus because they needed his aid in designing sensitive instruments for the new space missions. Eventually, Lovelock was put on a team proposing experiments to search for life on Mars.

  Sitting through meetings where biologists laid out plans to detect Martian microbes, Lovelock found himself unconvinced. “The flaw in their thinking,” Lovelock recalls in his biography, “was their assumption that they already knew what Martian life was like. . . . I gathered the distinct impression that they saw it as like life in the Mojave Desert.” 48

  But Lovelock, with an outsider’s perspective that would haunt him later, came at the problem from a different direction. “I think we need a general experiment,” he told the group, “something that looks for life itself, not the familiar attributes of life as we know it on Earth.” 49 Pressed by the program manager to propose experiments that looked for “life itself,” Lovelock was taken down a road that would lead him straight into the realms of Vernadsky’s biosphere.

  Lovelock’s background in physics, chemistry, and biology led him to see the problem in terms of planetary atmospheres. He knew that life was keeping the air oxygen-rich. Take the biosphere away, and that oxygen would chemically combine with other compounds such that, if you waited long enough, the Earth’s atmosphere would become oxygen-free. Without life, it would return to a state of “chemical equilibrium” dominated by the CO2 released from volcanoes.50

  Based on what he saw on Earth, Lovelock reasoned that life would always keep a planetary atmosphere in a state far from equilibrium. That meant the activity of life would constantly push on the planet’s chemistry. The biosphere’s continual resupply of oxygen, an element that would otherwise react away, was just one example of such a push.

  Over the next two years, Lovelock continued to visit JPL and continued to work out the details of his atmosphere-as-life-detector experiment. But then, in September of 1965, a flash of insight showed him there was more to his idea than just an experiment.

  In an office he shared with none other than a young Carl Sagan, Lovelock was poring over new data showing that the Martian atmosphere was dominated by CO2. Unlike Earth’s blanket of gases, Mars’s atmosphere was locked into the same kind of dead chemical equilibrium as that of Venus. A CO2-dominated atmosphere is exactly what you’d expect as the result of chemical reactions that were allowed to run their own course, like mixing a bunch of compounds together in a box and leaving the whole thing alone forever. It was at that moment that Lovelock saw the light.

  “It came to me suddenly, just like a flash of enlightenment, that [for the chemistry of the Earth’s atmosphere] to persist and keep stable, something must be regulating [it].” The identity of this “something” came to Lovelock just as quickly as the question had. “It dawned on me that somehow life was regulating the climate as well as the chemistry. Suddenly the image of the Earth as a living organism able to regulate its temperature and chemistry at a comfortable steady state emerged in my mind.” 51

  It was a powerful image. Lovelock saw the Earth as a single entity—“alive” in some sense—and regulating itself in the same way our bodies maintain their temperatures. Lovelock soon began fleshing out the details of his idea, looking for specific mechanisms life could harness to adjust conditions across an entire planet. As the work progressed, he realized he needed a name for the idea. He thought to call it the “Self-regulating Earth System Theory,” but a conversation with a neighbor, the novelist William Golding (author of Lord of the Flies), convinced him otherwise. Golding suggested Lovelock name the theory after the Greek goddess of the Earth, Gaia.52

  There is some irony in the fact that Carl Sagan, who did so much for our concept of Earth in its cosmic context, would be present for the insight that gave birth to Gaia theory. Given that Sagan was never very supportive of Lovelock’s idea, it is even more ironic that he’d serve as midwife to the next crucial step in its development.

  In the years following their divorce, the biologist Lynn Margulis almost single-handedly forced the scientific community to recognize the importance of cooperation, rather than just competition, in evolution. Her theory of endosymbiosis demonstrated how the tiny chemical-processing plants in our cells called organelles had once been independent organisms. Margulis proved that organelles—like mitochondria, for example—had been absorbed into larger bacteria billions of years ago to form a cooperative, symbiotic whole. This symbiotic evolution was likely the origin of the eukaryotic (nucleus-bearing) cells that transformed life’s trajectory during the Archean eon.53

  In the early 1970s, Margulis had become interested in the question of atmospheric oxygen and its microbial origin. When she asked her ex-husband, Carl Sagan, if he knew someone who might be good to talk with about the problem, he suggested Lovelock. From this unlikely introduction, Lovelock and Margulis began a collaboration that fully defined the Gaian concept of life as a self-regulating planetary system. Where Lovelock brought the top-down view of physics and chemistry, Margulis brought the essential bottom-up view of microbial life in all its plentitude and power.54

  The essence of Gaia theory, as elaborated in papers by Lovelock and Margulis, lies in the concept of feedbacks that we first encountered in considering the greenhouse effect.

  James Lovelock and biologist Lynn Margulis in front of a statue of Gaia.

  The temperature of the human body always hovers around 98.6 degrees Fahrenheit. That’s what is known as a steady state. At your death, your body drops back to room temperature. That’s equilibrium. The same ideas can be applied to the oxygen in the atmosphere. The current levels of oxygen are held in a steady state by chemical reactions driven by the presence of life. But how does life keep the oxygen levels steady? We’ve already seen how photosynthetic bacteria gave Earth its oxygen-rich air. But why did oxygen levels rise up to 21 percent, and no further? This is an important question, because if the concentration of oxygen in the air were to climb as high as 30 percent, the planet would become a tinderbox. Any lightning bolt would trigger fires that wouldn’t stop. So, what kept oxygen levels from rising above this dangerous threshold? To answer that question, Lovelock and Margulis turned to the idea of feedbacks.

  In their Gaia theory, Lovelock and Margulis argued that life as a whole exerted global negative feedbacks on the planet. Those feedbacks had kept the planet in a series of long-term steady states over its history that were always optimal for makin
g the planet habitable and inhabited. In other words, life kept the planet cozy for life. If, for example, oxygen levels rose too high, then the increased oxygen would, itself, trigger blooms of microorganisms whose biochemistry would lead to those levels being drawn back down. It was a very big idea indeed.

  Lovelock and Margulis were offering a scientific narrative whose ties to the scale of world-building myth were explicit. It was Vernadsky on steroids, a vision of planetary evolution where life was not just a force, but a force with its own kind of intention. But just because an idea is big and beautiful doesn’t mean it’s true. In particular, with the all-important idea of intention—meaning life’s intention with its Gaian feedbacks—the two scientists opened a Pandora’s box.

  THE BIOSPHERE BOUND

  Oberon Zell-Ravenheart (whose given name is Timothy Zell) never met a New Age idea he didn’t embrace. He is a pagan and a shaman. A fully ordained priest in the Fellowship of Isis, he also finds time to work as an initiate in the Egyptian Church of the Eternal Source. Zell-Ravenheart is also a Gaian, and that, in a nutshell, is why so many scientists hated Lovelock and Margulis’s big, beautiful idea.

  Early on, Gaia found itself scorned as a scientific theory by scientists but wildly popular in the larger culture. As historian and philosopher Michael Ruse puts it: “[The public] embraced Lovelock and his hypothesis with enthusiasm. People got into Gaia groups. Churches had Gaia services, sometimes with new music written especially for the occasion. There was a Gaia atlas, Gaia gardening, Gaia herbs, Gaia retreats, Gaia networking, and much more.”55

  Gaia theory came along just as the environmental movement and post-’60s New Ageism were going mainstream. In 1979, nuclear power became a national issue thanks to the partial core meltdown at the Three Mile Island generating station near Harrisburg, Pennsylvania. The pollution-driven evacuation of Love Canal in Upstate New York became the poster child for what environmental degradation looked like. Gaia theory, with its evocation of Earth as a single living organism—a vast planetary mother—channeled popular ecological concerns with an alternative vision of humanity’s place in the scheme of things.