As 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.
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?
>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.
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.
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.
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.
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.
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.
>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.
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.
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:
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:
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.)
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:
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.
CoreSet|6 years 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...
FooHentai|6 years ago
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?
Sandman|6 years ago
gameswithgo|6 years ago
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.
namirez|6 years ago
https://arxiv.org/pdf/1804.03748.pdf
jerf|6 years ago
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.
vilhelm_s|6 years ago
https://arxiv.org/pdf/1704.07263.pdf
chimi|6 years ago
nostrademons|6 years ago
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.
CoreSet|6 years ago
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"
ncmncm|6 years ago
willis936|6 years ago
https://youtu.be/8xDK2LgSeyk
throwaway5d097|6 years ago
ilaksh|6 years ago
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?
ncmncm|6 years ago
Donald|6 years ago
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.
ncmncm|6 years ago
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.
unknown|6 years ago
[deleted]
nostrademons|6 years ago
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:
https://en.wikipedia.org/wiki/Missoula_Floods
ncmncm|6 years ago
Most likely almost all of human history in the Americas, and maybe too in Africa, is 200 feet under the sea.
namirez|6 years ago
https://en.wikipedia.org/wiki/Holocene_extinction
chimi|6 years ago
nostrademons|6 years ago
https://www.theatlantic.com/science/archive/2017/06/the-ends...
rexaliquid|6 years ago