{"id":140541,"date":"2019-08-26T12:00:52","date_gmt":"2019-08-26T11:00:52","guid":{"rendered":"https:\/\/www.transcend.org\/tms\/?p=140541"},"modified":"2019-11-19T10:50:49","modified_gmt":"2019-11-19T10:50:49","slug":"the-anthropocene-is-a-joke","status":"publish","type":"post","link":"https:\/\/www.transcend.org\/tms\/2019\/08\/the-anthropocene-is-a-joke\/","title":{"rendered":"The Anthropocene Is a Joke"},"content":{"rendered":"

On geological timescales, human civilization is an event, not an epoch.<\/em><\/p><\/blockquote>\n

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Stuart Gleave \/ Getty<\/p><\/div>\n

13 Aug 2019 – <\/em>Humans are now living in a new geological epoch of our own making: the Anthropocene. Or so we\u2019re told. Whereas some epochs in Earth history stretch more than 40 million years, this new chapter started maybe 400 years ago, when carbon dioxide dipped by a few parts per million in the atmosphere. Or perhaps, as a panel of scientists voted earlier this year<\/a>, the epoch started as recently as 75 years ago, when atomic weapons began to dust the planet with an evanescence of strange radioisotopes.<\/p>\n

These are unusual claims about geology, a field that typically deals with mile-thick packages of rock stacked up over tens of millions of years, wherein entire mountain ranges are born and weather away to nothing within a single unit of time, in which extremely precise rock dates\u2014single-frame snapshots from deep time\u2014can come with 50,000-year error bars, a span almost 10 times as long as all of recorded human history. If having an epoch shorter than an error bar seems strange, well, so is the Anthropocene.<\/p>\n

So what to make of this new \u201cepoch\u201d of geological time? Do we deserve it? Sure, humans move around an unbelievable amount of rock every year, profoundly reshaping the world in our own image. And, yes, we\u2019re currently warping the chemistry of the atmosphere and oceans violently, and in ways that have analogues in only a few terrifying chapters buried deep in Earth\u2019s history. Each year we spew more than 100 times as much CO2<\/sub> into the air as volcanoes do, and we\u2019re currently overseeing the biggest disruption to the planet\u2019s nitrogen cycle in 2.5 billion years. But despite this incredible effort, all is vanity. Very little of our handiwork will survive the obliteration of the ages. If 100 million years can easily wear the Himalayas flat, what chance will San Francisco or New York have?<\/p>\n

Read: The cataclysmic break that (maybe) occurred in 1950<\/a><\/em><\/strong><\/p><\/blockquote>\n

The idea of the Anthropocene is an interesting thought experiment. For those invested in the stratigraphic arcana of this infinitesimal moment in time, it serves as a useful catalog of our junk. But it can also serve to inflate humanity\u2019s legacy on an ever-churning planet that will quickly destroy\u2014or conceal forever\u2014even our most awesome creations.<\/p>\n

What paltry smudge of artifacts we do leave behind, in those rare corners of the continents where sediment accumulates and is quickly buried\u2014safe from erosion\u2019s continuous defacing\u2014will be extremely unlikely to be exposed at the surface, at any given time, at any given place, tens of millions or hundreds of millions of years in the geological future. Sic transit gloria mundi<\/em>.<\/p>\n

Perhaps, someday, our signal in the rocks will be found, but only if eagle-eyed stratigraphers, from God knows where on the tree of life, crisscross their own rearranged Earth, assiduously trying to find us. But they would be unlikely to be rewarded for their effort. At the end of all their travels\u2014after cataloging all the bedrock of the entire planet\u2014they might finally be led to an odd, razor-thin stratum hiding halfway up some eroding, far-flung desert canyon. If they then somehow found an accompanying plaque left behind by humanity that purports to assign this unusual layer its own epoch\u2014sandwiched in these cliffs, and embarrassed above and below by gigantic edifices of limestone, siltstone, and shale\u2014this claim would amount to evidence of little more than our own species\u2019 astounding anthropocentrism. Unless we fast learn how to endure on this planet, and on a scale far beyond anything we\u2019ve yet proved ourselves capable of, the detritus of civilization will be quickly devoured by the maw of deep time.<\/p>\n

Geological time is deep beyond all comprehension. If you were to run a 26.2-mile marathon covering the entire retrospective sweep of Earth\u2019s history, the first five-foot stride would land you two Ice Ages ago and more than 150,000 years before the whole history of human civilization. In other words, geologically and to a first approximation, all of recorded human history is irrelevant: a subliminally fast 5,000-year span that is over almost as soon as you first lift up your heel, crammed entirely into the very end of an otherwise humdrum Pleistocene Ice Age interglacial. (NB: That this otherwise typical and temporary warm spell of the Pleistocene has also <\/em>been strangely given its own<\/em> epoch, the so-called Holocene\u2014quite unlike the dozens of similar interglacials that came before it\u2014is the original sin of anthropocentric geology.)<\/p>\n

If instead your marathon was forward in time, after one stride the oceans and atmosphere would have just about recovered from our wild chemistry experiment on the planet, and no surface record of human civilization would yet remain. Another stride would plunge you into another true Pleistocene-style Ice Age, with seas 400 feet lower than they are today. That missing water would instead be locked up in massive ice sheets that now bear down on the continents, plowing moraines into future islands, obliterating everything in their path, and spewing glaciers at their crumbling margins. These plots of land were once, in some forgotten time, called New York City, or Illinois. All of future time would stretch out before you. After a mile and a half, the continents would reunite in one of their many iterations of the supercontinent cycle, its shores and mountain valleys hosting creatures beyond imagining. Not only will humanity not be a part of this picture, but virtually no geological record will remain of us whatsoever. Not plastic birthday balloons, not piles of denuded chicken bones, not Charlton Heston shaking his fist at some littoral colossus. It will all be worn away, destroyed, or hidden forever.<\/p>\n

Read: Geology\u2019s timekeepers are feuding<\/a><\/em><\/strong><\/p><\/blockquote>\n

For context, let\u2019s compare the eventual geological legacy of humanity (somewhat unfairly) to that of the dinosaurs, whose reign spanned many<\/em> epochs and lasted a functionally eternal 180 million years\u201436,000 times as long as recorded human history so far. But you would never know this near-endless age was so thoroughly dominated by the terrible reptiles by looking to the rock record of the entire eastern half of North America. Here, dinosaurs scarcely left behind a record at all. And not because they weren\u2019t here the entire time\u2014with millions of generations of untold dinosaurs living, hunting, mating, dying, foraging, migrating, evolving, and enduring throughout, up and down the continent, in great herds and in solitary ambushes. But the number of sites within that entire yawning span, and over these thousands of square miles, where they could have been preserved\u2014or that weren\u2019t destroyed by later erosion, or that happen to be exposed at the surface today\u2014was vanishingly small.<\/p>\n

Yes, billions of dinosaur bodies died and fell to the Earth here in this span, and trillions more dinosaur footsteps pressed into the Earth, but hardly a trace remains today. A cryptic smattering of lakeside footprints represents their entire contribution to the Triassic period. A few bones and footsteps miraculously preserved in New England and Nova Scotia are all that remains from the entire 27-million-year Early Jurassic epoch. No trace of dinosaurs remains whatsoever from the 18-million-year Late Jurassic. A handful of bones from one layer in Maryland represents the entire 45-million-year Early Cretaceous; the Late Cretaceous gives up a Hadrosaurus in New Jersey, and part of a tyrannosaur in Alabama, but mostly comprises unimpressive fragments of bone and teeth that cover the remaining 34 million years of the Earth\u2019s most storied age, until doomsday. If one wanted to know what a particular 10-, 100-, or 1,000-year span was like, buried in this vastness of time (or, even worse, in some particular region of the continent), good luck.<\/p>\n

This astounding paucity can be explained by the fact that there just aren\u2019t that many rocks that survived these extreme gulfs of time, over this vast province. And even among those rocks that did <\/em>survive, and which are exposed today, the conditions for fossil preservation were rare beyond measure. Each fossil was its own miracle, sampled randomly from almost 200 million years of history\u2014a few stray, windblown pages of a library.<\/p>\n

If, in the final 7,000 years of their reign, dinosaurs became hyperintelligent, built a civilization, started asteroid mining, and did so for centuries before forgetting to carry the one on an orbital calculation, thereby sending that famous valedictory six-mile space rock hurtling senselessly toward the Earth themselves<\/em>\u2014it would be virtually impossible to tell. All we do know is that an asteroid did hit, and that the fossils in the millions of years afterward look very different than in the millions of years prior.<\/p>\n

Read: What caused the dinosaur extinction?<\/a><\/em><\/strong><\/p><\/blockquote>\n

So that\u2019s what 180 million years of complete dominance buys you in the fossil record. What, then, will a few decades of industrial civilization get us? This is the central question of the Anthropocene\u2014an epoch that supposedly started, not tens of millions of years ago, but perhaps during the Truman administration. Will our influence on the rock record really be so profound to geologists 100 million years from now, whoever they are, that they would look back and be tempted to declare the past few decades or centuries a bona fide epoch of its own?<\/p>\n

An important thing to keep in mind about paleontology is that most fossil-bearing rock outcrops are marine\u2014that is, they\u2019re from the bottom of the sea. As a result, we have a much higher resolution of the history of life in the oceans than on land. That\u2019s because the sea, for the most part, is where sediment goes to accumulate. Things fall apart on land and in general get destroyed by weathering and erosion, and get carried to the sea as sand grains and silt and in solution. If it weren\u2019t for the ceaseless creation of new mountain ranges, the surface of the Earth would quickly be rendered flat. Yes, some cities, such as New Orleans, Dhaka, and Beijing, sit in subsiding sedimentary basins and, at first pass, seem promising candidates for preservation. But as the example of the dinosaurs shows, the chance that any city-swallowing delta deposit from a window of time only a few centuries wide would be lucky enough to be not only buried and preserved for safekeeping, but then subsequently not destroyed<\/em>\u2014in the ravenous maw of a subduction zone, or sinking too close to the cleansing metamorphic forge of Earth\u2019s mantle, or mutilated in some mountain-making continental collision\u2014and then<\/em>, after all that,<\/em> find itself, at a given point in the far future, fantastically lucky enough to have been serendipitously pushed up just<\/em> enough so as to be exposed at the surface, but not too<\/em> high as to have been quickly destroyed by erosion \u2026 is virtually nil. In the Grand Canyon, and over much of the Southwest U.S. (and even across the entire world), there\u2019s a billion-year<\/em> gap between rock formations. That history\u2014that former forever\u2014as marvelous as it may have been in that region of the world, will never be recovered.<\/p>\n

Even worse for our long-term preservation\u2014long after humanity\u2019s brief, artificial greenhouse fever\u2014we\u2019re very likely to return to our regularly scheduled programming and dive back into a punishing Ice Age in the next half-million years. This means that sea level\u2014after shooting up in the coming millennia by our own hand, and potentially burying coastal settlements in sediment (good for fossilization)\u2014will eventually fall hundreds of feet below where it is today, and subject the shallow continental shelves, along with our once submerged cities and magnificent seams of garbage, to the cold winds of erosion (bad for fossilization), where they\u2019ll be mostly reduced to nothing. Meanwhile, the top half of our continent will be scoured clean by ice sheets. The lone and level sands stretch far away.<\/em><\/p>\n

But what would we leave on the seafloor, where most sedimentary rock is made, where most of the fossils are, and where we have a slightly better chance of recording our decades-long \u201cepoch\u201d in the rocks? Well, many marine sediments in the fossil record accumulated, over untold eons, from the diaphanous snowfall of plankton and silt, at a rate of little more than a centimeter per thousand years. Given this loose metric (and our current maturity as a species), a dozen centimeters of muck seems an optimistic goal for civilization.<\/p>\n

A dozen centimeters is a pathetic epoch, but epoch or not, it would be an extremely interesting layer. It\u2019s tempting to think a whisper of atomic-weapons testing would remain. The Promethean fire unleashed by the Manhattan Project was an earth-changing invention, its strange fallout destined to endure in some form as an unmistakable geological marker of the Anthropocene. But the longest-lived radioisotope from radioactive fallout, iodine-129, has a half-life of less than 16 million years. If there were a nuclear holocaust in the Triassic, among warring prosauropods, we wouldn\u2019t know about it.<\/p>\n

What else of us could be sampled from this sliver of deep-sea-muck-turned-rock\u2014these Anthropocene clays and shale layers? Pass it through a mass spectrometer and you would see, encoded in its elements, the story of the entire planet in this strange interval, the Great Derangement of the Earth\u2019s systems by civilization. You would see our lightning-fast injection of hundreds of gigatons of light carbon into the atmosphere written in the strange skew of carbon isotopes in this rock\u2014as you do in rocks from the many previous carbon-cycle disasters of Earth history. The massive global-warming pulse created by this carbon disaster would be written in oxygen isotopes. The sulfur, nitrogen, thallium, and uranium isotopes in these rocks (to mention just a few) would whisper to you\u2014again, in squiggles on a graph\u2014that the global ocean lost much of its oxygen during this brief but enigmatic interval. Strontium isotopes would tell you that rock weathering dramatically accelerated worldwide for a few tens of thousands of years as sweltering, violent storms attacked the rocks and wore down the continents during a brief, CO2<\/sub>-driven fever.<\/p>\n

These trace isotopes may be the most enduring signals of humanity, together telling much of the story of our strange centuries, in only a few centimeters of ocean rock. They will speak, to those who know how to listen, of life-supporting geochemical cycles going haywire in an eyeblink of geological time, hinted at in small samples from our seam of strange strata that interrupts mile-thick formations of otherwise normal rock. Plastic, that ubiquitous pollutant of the oceans, might<\/em> be detectable by analyzing small samples of this sediment\u2014appearing, like many organic biomarkers in the fossil record, as a rumor of strangely heavy hydrocarbons. Unassuming peaks on a chromatograph would stand in for all of modernity. Perhaps, perhaps<\/em>, if one was extremely<\/em> lucky in surveying this strange layer, across miles of desert-canyon walls, a lone, carbonized, and unrecognizable piece of fishing equipment may sit perplexingly embedded in this dark line in the cliffs. Some \u201cepoch\u201d this.<\/p>\n

The most enduring geological legacy, instead, will be the extinctions we cause. The first wave of human-driven extinctions, and the largest hit to terrestrial megafauna since the extinction of the dinosaurs, began tens of thousands of years ago, as people began to spread out into new continents and islands, wiping out everything we tend to think of as \u201cIce Age\u201d fauna\u2014mammoths, mastodons, giant wombats, giant ground sloths, giant armadillos, woolly rhinoceroses, giant beavers, etc. This early, staggered, human-driven extinction event is as reasonable a starting date as any for the Anthropocene and one that has, in fact, been proposed. However, a few thousand years\u2014or even a few tens of thousands of years\u2014will be virtually indistinguishable in the rocks a hundred million years hence. That is, it would not be obvious to the geologists of the far future that these prehistoric human-caused extinctions were not simultaneous with our own modern-day depredations on the environment. The clear-cutting of the rain forest to build roads and palm-oil plantations, the plowing of the seabed on a continental scale, the rapid changes to the ocean and atmosphere\u2019s chemistry, and all the rest would appear simultaneous with the extinction of the woolly mammoth. To future geologists, the modern debate about whether the Anthropocene started 10 minutes ago or 10,000 years ago will be a bit like arguing with your spouse on your 50th wedding anniversary about which nanosecond you got married.<\/p>\n

Read: In a few centuries, cows could be the largest land animals left<\/a><\/em><\/strong><\/p><\/blockquote>\n

What humans are doing on the planet, then, unless we endure for millions to tens of millions of years, is extremely transient. In fact, there exists a better word in geology than epoch<\/em> to describe our moment in the sun thus far: event<\/em>. Indeed, there have been many similarly disruptive, rapid, and unusual episodes scattered throughout Earth history\u2014wild climate fluctuations, dramatic sea-level rises and falls, global ocean-chemistry disasters, and biodiversity catastrophes. They appear as strange lines in the rock, but no one calls them epochs. Some reach the arbitrary threshold of \u201cmass extinction,\u201d but many have no name. Moreover, lasting only a few tens of thousands to hundreds of thousands of years in duration, they\u2019re all considered events. In our marathon of Earth history, the epochs would occasionally pass by on the side of the road like towns, while these point-like \u201cevents\u201d would present themselves to us only fleetingly, like pebbles underfoot.<\/p>\n

Fifty-six million years ago, the Earth belched 5,000 gigatons of carbon (the equivalent of burning all our fossil-fuel reserves) over roughly 5,000 years into the oceans and atmosphere, and the planet warmed 5 to 8 degrees Celsius. The warming set off megafloods and storms, and wiped out coral reefs globally. It took the planet more than 150,000 years to cool off. But this \u201cPaleocene-Eocene Thermal Maximum\u201d is considered an event<\/em>.<\/p>\n

Thirty-eight million years before that, buried in the backwaters of the late Cretaceous, CO2<\/sub> jumped as many as 2,400 parts per million, the planet warmed perhaps 8 degrees Celsius, the ocean lost half its oxygen (in our own time, the ocean has lost a\u2014still alarming\u20142 percent of its oxygen), and seawater reached 36 degrees Celsius (97 degrees Fahrenheit) over much of the globe. Extinction swept through the seas. In all, it took more than half a million years. This was Cretaceous Oceanic Anoxic Event <\/em>2. Though it was no epoch, if you had been born 200,000 years into this event, you\u2019d die roughly 300,000 years before it was over.<\/p>\n

A similar catastrophe struck 28 million years before, in the early Cretaceous, and again 60 million years earlier still in the Jurassic. And, again, 201 million years ago. And halfway through the Triassic, 234 million years ago. And 250 million, 252 million, and 262 million years ago. The first major mass extinction, 445 million years ago, took place in multiple pulses across a million years. An event. The second major mass extinction, 70 million years later, took place over 600,000 years\u2014400,000 years longer than the evolutionary history of Homo sapiens<\/em>. These are transformative, planet-changing paroxysms that last on the order of hundreds of thousands of years, reroute the trajectory of life, and leave little more than strange black lines in the rocks, buried within giant stacks of rocks that make up the broader epochs. But none of them constitute epochs in and of themselves. All were events<\/em>, and all\u2014at only a few tens of thousands, to hundreds of thousands of years\u2014were blisteringly short<\/em>.<\/p>\n

The idea that we\u2019re in a new epoch is a profoundly optimistic one, for it implies that we\u2019ll persist into the future as an industrial technological civilization on something like a geological timescale. It implies that we are at the dawning of the astrobiologist David Grinspoon\u2019s \u201cSapiezoic Eon\u201d\u2014that expansive, creative, open-ended future in which human technology represents a new and enduring feature of the planet on par with the biological innovations of the Cambrian Explosion\u2014rather than heading for the impending, terminal consummation of a major mass extinction, ending with all the conclusive destruction of apocalypses past.<\/p>\n

Until we prove ourselves capable of an Anthropocene worthy of the name, perhaps we should more humbly refer to this provisional moment of Earth history that we\u2019re living through as we do the many other disruptive spasms in Earth history. Though dreadfully less catchy, perhaps we could call it the \u201cMid-Pleistocene Thermal Maximum.\u201d After all, though the mammoths are gone, their Ice Age is only on hold, delayed as it is for a few tens of thousands of years by the coming greenhouse fever. Or perhaps we\u2019re living through the \u201cPleistocene Carbon Isotope Excursion,\u201d as we call many of the mysterious global paroxysms from the earliest era of animal life, the Paleozoic. Or maybe we\u2019re even at the dawning of the \u201cQuaternary Anoxic Event\u201d or, God forbid, the \u201cEnd-Pleistocene Mass Extinction\u201d if shit really hits the fan in the next few centuries. But please, not the Anthropocene. You wouldn\u2019t stand next to a T. rex<\/em> being vaporized 66 million years ago and be tempted to announce to the dawning of the hour-long Asteroidocene. You would at least wait for the dust to settle before declaring the dawn of the age of mammals.<\/p>\n

The idea of the Anthropocene inflates our own importance by promising eternal geological life to our creations. It is of a thread with our species\u2019 peculiar, self-styled exceptionalism\u2014from the animal kingdom, from nature, from the systems that govern it, and from time itself. This illusion may, in the long run, get us all killed. We haven\u2019t earned an Anthropocene epoch yet. If someday in the distant future we have<\/em>, it will be an astounding testament to a species that, after a colicky, globe-threatening infancy, learned that it was not separate from Earth history, but a contiguous part of the systems that have kept this miraculous marble world habitable for billions of years.<\/p>\n

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