The Arrogance of the Anthropocene
theatlantic.comAs an addendum, the author, Peter Brannen, published another article with The Atlantic titled "What Made Me Reconsider the Anthropocene" four days ago.
In it, he responds to criticism and ultimately comes to the conclusion that - even if no trace of humanity is left (no civilization, tools, etc) in "deep time" - the biosphere itself has been changed by humanity, and that gives the concept of the Anthroprocene validity.
https://www.theatlantic.com/science/archive/2019/10/anthropo...
I think this should be front-and-center rather than an addendum point - Can't help but question the good faith of an author putting this article up while only recently having published one that appears to take an opposite view. Frankly, smells like click bait dressed up as high-brow op-ed.
I was going to post a comment in response to some of the points in the article, but upon seeing that the other article existed... what's the point?
I read both and think that the second supports the point made in the first.
The point of the anthropocene, as presented in the second article, is to acknowledge the effect humans have already had on the earth. The point of the first is to acknowledge how little an effect that is, relative to other events in geologic time. The events described in that article still stand - global temperature differences of 8C over a few tens of thousands of years, sea levels 400 feet lower (and that was a blink of an eye ago in geologic time), a 90M year long ice age.
> The point of the first is to acknowledge how little an effect that is, relative to other events in geologic time.
And speaking only about that geologic time is deceptive, without mentioning context: for the biggest part of the whole geologic time, not even multi-cellular life existed. Half of the whole geologic time, nothing was able to depend on oxygen as the modern life does -- there wasn't much of it in the atmosphere.
The time human civilizations existed is microscopic in comparison to these spans, but that much shorter time is what defines us.
And in that time, the climate was indeed quite stable. Until the last hundred or two years.
And humans did make immense impact on the life forms, and will continue to make.
I thought that was actually the point of the article. The author freely admits that from a human perspective, climate change and habitat destruction and the bleaching of coral reefs are a big deal. The point he's making is that from a planetary perspective, humans are insignificant. Indeed, from a planetary perspective multi-cellular life is insignificant, and life at all is a minority.
The thing is that much of the debate over global warming has been framed in planetary terms. If you frame it in human terms, you already have a good argument: climate change will cause mass migrations, historically mass migrations have caused massive wars and the collapse of civilizations, I don't want to die in a war while my whole civilization collapses, ergo it's probably a good idea to solve or at least adapt to this climate change thing before shit hits the fan. But if you frame it in terms of "climate change will make the earth uninhabitable" or even "climate change will lead to the extinction of humanity", a.) you're probably wrong - our species is remarkably resilient, and we have lived through large planetary-scale shifts in the earth's climate b.) the earth has been made uninhabitable to much of life in the past, and yet we're here and c.) so what, we'll all be dead.
From planetary perspective, multicellular life was and is huge. Oxygen catastrophe is not called that because it was invisible from space. Nor are ok deposits geologically insignificant.
It is big timeframe though compared to anthropocene.
The warming is indeed planetary, but not the magnitude of the earlier atmospheric changes. The crust changes are more visible for now, especially mining. The temperature will be pretty important at about +1 C out more globally - not quite yet. At that level moisture circulation would get affected a lot...
It's a little backwards. The top level article is the original. The grandparent linked article is the author's response from last week indicating responses to the top level article made him re-think and feel he was wrong.
Ah, thank you. I mistakenly believed this one was new given it being posted.
Cool, I didn't know about that one! I'm going to check it out, thanks for the link!
>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—it would be virtually impossible to tell.
I consider this claim to be complete nonsense. Change my mind. There are 4 billion year old rocks still on the earth to be found. 7,000 years of civilization is not going to be completely erased in a few million.
Most likely it is nonsense. The carbon and nitrogen composition of sedimentary layers will show anomalies in case of intelligent civilizations.
The article you link directly contradicts your claim.
I think we'd be able to find a previous civilization of our current technological advancement by finding a lot of veins of mineral resources mined out, except for the trailings around the edges. I've never heard even a whisper of such a mineral formation being found, and with the amount of money such mineral industrial research accounts for, I suspect by now we would have found such a thing if it exists, especially if it existed in quantity.
There may be no structures or artifacts that survived 65 millions years, but there's plenty of holes that would have, in natural structures that to all appearances are older than 65 million years, should have been about as available then as they are now, and are obviously undisturbed.
What if they used different minerals because before they mined them out, different minerals were present? To what extent is our dependence on iron, copper, and bronze a historical accident because that's what was available to our ancestors, and to what extent might we have used different metals if easily-extractable ores for them were present?
Despite being the third most common element in the earth's crust, aluminum cost more than gold and was rarely used for industrial purposes before the Hall-Heroult process for smelting it from alumina and the Bayer process for smelting it from Bauxite.
Rare-earths display a similar profile: they are abundant in the earth's crust, but not in any form that we can easily mine and extract. What if a past dinosaur civilization mined out all the easy rare-earth deposits building iPhones and batteries?
"What if they used different minerals because before they mined them out, different minerals were present?"
I'd point out I didn't say that all the minerals were gone, but that the good veins were gone, surrounded by the stuff they left behind. I say that because that's how we do it now, and we do it for economic reasons that any civilization will be subject to. This is a particular pattern that I'm not aware of anyone ever observing.
I am also not aware of anyone even proposing anomalies in element distribution of things like rare earths. Rare earths aren't as rare as their name suggests as I'm sure you know, but as you go up the periodic table, you do naturally get less of them in the crust for several reasons (less created in the supernovas that created the heavy elements, and more of it sinking in the earth during the early phase). It's possible that our understanding of elemental distribution is a "just so" story created by what turns out to be artificial manipulation of the contents in the past, but given that our understanding of the processes that led to the current distribution includes a lot of astronomical observations, it'd be one heck of a "just so" story at this point. I am not aware of even a hint of an observation that requires an intelligent civilization on Earth in the past.
I'd say if you really want to have some fun, hypothesize a dinosaur civilization that attained some sort of singularity, and on the way out chose to leave behind machines that restored Earth to its "natural" state over the course of a few centuries or something, thus wiping out all traces of their presence to make way for the next civilization. It's not impossible to imagine a human singularity ending that way. Come up with some semi-compelling reason why all or at least most civilizations would tend to do that and you've got a fun premise for a sci-fi story universe. Perhaps we're not merely the second, but the dozenth. Heck, maybe we're not even the first primate.
(Another bonus "thing we clearly don't see": At the current rate of human advancement, in another couple hundred to couple thousand years, even putting aside really high-end nanotech, our primary contribution to the history of planet Earth may not be the sudden extinction of a lot of life forms, but the sudden proliferation of a lot of life forms, along with visible cross-transfer of genetic characteristics that couldn't possibly have naturally occurred. Even if the intelligent civilization completely keeled over dead, or Transcended, or whatever, the mark on the planet's genetic history would be visible quite possibly right up to the point the Sun sterilizes the Earth. We aren't there yet, but we are darned close. As much fun as a lot of people seem to derive from wringing their hands and posturing about how terrible humanity is, on a geological time scale, we may not be living in an Athropocene Extinction, but instead in the gestational phase of the Anthropocene Explosion.)
Of all of the above, the existence of holes seem to be the only compelling traces.
I mention it because it's the earliest one I can think of in our technological development. If we continue advancing, we will eventually get to that genetic diversification bit, but it seems that happens after you get the point where you can wipe out your own civilization with nukes, so that one is much less reliable.
(The Singularity paragraph is just for fun. Almost by definition, there is no reasonable way to ever collect evidence for it.)
In addition to the Schmidt/Frank paper (already linked to by namirez in another comment), there's a cute suggestion that the best place to look for dinosaur civ remnants should be on the moon, Mars, and the asteroids, because their spacecrafts should decay less quickly than their Earth settlements. :)
By some back of the napkin calculations I did once, I found that a couple billion years is enough for the tectonic plates to have completely recycled themselves into the mantle, erasing any structures built on them.
Correct, the stratigraphic record is 3.5 billion years old. At least if this (https://xkcd.com/1194/) xkcd is to be truested.
What percentage of 4 billion year old rocks are still on earth? What percentage of rocks currently on the earth bear traces of humanity?
When I've gone on Geology 101 field trips, once or twice the instructor was like "And this rock was formed over a billion years ago." It was invariably followed by "Deep within the earth's crust, several miles below the surface." Rocks that are on the surface get weathered and eroded; quartz and feldspar on exposed granite become successive layers of sandstone.
What about if dinosaurs got to the point of early hunter-gatherers - establishing communities, language, basic tools - but were then wiped out?
It's different from the case he cites, but tracks the general point that there are limits to what we can learn about prehistory / "deep time"
If we can find their fossilized skeletons, can't we find their stone tools? Maybe scattered around their ritual burials?
Think of it this way: distance in time is like distance in space. It's just another dimension (with the catch that apparently we can't actually move backward). The dinosaurs are as far from us as Alpha Centauri, maybe further.
This is a reasonable way of looking at time for certain purposes, and the conversion factor is c. So, 65 million years "ago" is also 65 million light-years "away" in the -t direction.
There are plenty of rocks from the late ("upper") Cretaceous, with a boundary containing elevated iridium. Suppose some microscopically thin boundary, microscopically lower, had a slightly different carbon isotope mixture. Who would notice, even looking? Would the two be even distinguishable, or hopelessly jumbled? Indeed, is anyone looking now? Would there be any reason to conclude that the difference was not also caused by the meteorite?
Outside of a blip in CO2 emissions and soil nitrogen, and a dramatic decrease in biodiversity, we will leave almost no trace if we disappeared tonight.
If nothing else, telltale traces of our nuclear industries will be clearly identifiable. There was a natural nuclear reactor in what is now Gabon, and the fission products it left behind (e.g. Rutherfordium) are how we know it was there.
For a while, until it all decays. But the total amount of material involved is minuscule. You would be looking for parts per trillion, if indeed you were bothering to look at all. And what would draw your attention to look?
There are fossils of hundreds of millions of years old, and microfossils of microorganisms over 3 billion years old. Why couldn't there be fossils of technology?
It's obvious that human history is very short but it's less obvious that all of our buildings and trash will be so hard to find underground in five million years or so.
Wouldn't there at least be some places where ruins or landfills were largely exposed? And aren't there lots of materials that would stand out since they degrade slowly?
For example, what is going to happen to all of the concrete and steel in Manhattan in the course of five million years? Will it really be compressed to a thin layer that is barely noticeable or something?
It will all wash away, sand grain by sand grain. You can see the erosion of stone temples even a thousand years old, made of harder stuff than concrete.
The steel will wash away?
It will rust first, and the rust will wash away. The glass will wash away. Water conquers all.
>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?
Yes, there will be a thin but noticeable layer of hydrocarbons and odd pollution signatures in the crust that will act as a permanent geologic record of our existence.
"Humanity: it was thin but noticeable."
If you were specifically looking for it.
Somebody might notice a lack of elephant teeth above a peculiar boundary, or a reduction in fish bones and corals, and look closer at the boundary. But to notice a lack is much harder than to notice the advent of something new. A layer of paperclips might not attract much attention, once oxidized, or be interpreted with anything like fidelity.
The holocene always struck me as odd. Here we have the final geologic epoch, and it's 10,000 years old, and every other geologic epoch is ~50M years long. And it just happens to coincide with the rise of our species, who just happens to be the one creating the taxonomy.
Paleohistory is pretty fascinating, and it's easy to forget just how small we are on this big earth and how much things differ from today. For example:
We're technically in an icehouse age. An icehouse age is defined as "any period of time where glaciers exist anywhere on the planet". For about 80% of geologic time, there is no such thing as a glacier, or of snow and ice for that matter. The entire earth's surface is above freezing, even the North and South poles. What we know of as an "ice age" (a glaciation) is a feature only of icehouse states. We currently happen to be in an interglacial of an icehouse age, which is why we think of this as being a warm period. But geologically, the earth is well below its temperature average.
https://en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth
It's likely that the earth has completely frozen over on at least two occasions, with the entire planet being encased in a gigantic ice sheet like Europa:
https://en.wikipedia.org/wiki/Snowball_Earth
The larger of these two incidents may have been triggered by the evolution of photosynthesis and the addition of oxygen into the earth's atmosphere, which also likely caused a major mass extinction among the dominant anaerobic bacteria of the time:
https://en.wikipedia.org/wiki/Great_Oxidation_Event
Sea level over time has fluctuated by 300-400 meters. That means that anything at an altitude of less than about 1000 feet (which is the vast majority of human settlements) was once underwater. (Well, technically land level fluctuates more than sea level, so most of these low-lying areas are actually sediment weathered off of nearby mountains.)
https://en.wikipedia.org/wiki/Past_sea_level
There've been some massive outburst floods in the past, like the draining of Glacial Lake Missoula (a pleistocene lake roughly half the volume of Lake Michigan, held in by an ice dam on the Clark River nearly 2000 feet tall) which released an outflow 13 times the size of the Amazon River:
And produced the whole Columbia Gorge in just two weeks.
Most likely almost all of human history in the Americas, and maybe too in Africa, is 200 feet under the sea.
It seems to me this person is missing the point. When people talk about Anthropocene, they're not talking about geological or fossil evidence left behind by humans in million of years. Anthropocene refers to the Holocene or the sixth mass extinction on the planet.
My understanding is that the Anthropocene is definable because human gas emissions have created a visible layer in the rock strata that will be evident for millions of years. Geological time from now, there will be a black line in the rocks that will include the toxic chemicals coming from our industrial processes and tail pipes.
He makes the point in the article that there are innumerable unnamed razor-thin layers in the rocks already. What's one more? Why would anyone be drawn to study that one?
Okay, now I get it. I missed that part of the article. That's the arrogance. I like the ideas in a lot of these articles, I just don't have time to read them all. I miss the old days of tldr's.
I think you are right.
He wrote a similar piece on why earth is not in the middle of a sixth mass extinction:
https://www.theatlantic.com/science/archive/2017/06/the-ends...
Holocene and Anthropocene refer to the epoch, not the extinction event occurring during that epoch. An epoch is a measure of geological time.