Are we in the Anthropocene? Geologists could define new epoch for Earth
nature.com
nature.com
> "Years of debate among the group’s multidisciplinary members led them to identify a host of signals — radioactive isotopes from nuclear-bomb tests, ash from fossil-fuel combustion, microplastics, pesticides — that would be trapped in the strata of an Anthropocene-defining site. These began to appear in the early 1950s, when a booming human population started consuming materials and creating new ones faster than ever."
There's also just the sheer mass of material being moved and redistributed due to things like mega-dams, large-scale mining and earthmoving, construction etc.
> "Human activities have increased fluvial sediment delivery by 215% while simultaneously decreasing the amount of fluvial sediment that reaches the ocean by 49%, and societal consumption of sediment over the same period has increased by more than 2,500%."
"Earth’s sediment cycle during the Anthropocene" (2022)
https://www.nature.com/articles/s43017-021-00253-w
I don't know why anyone would want to deny this reality, other than to avoid international regulation of certain kinds of activities, like burning coal, for example.
Are you a time-traveler or a prophet?
If we were studying an extraterrestrial planet and discovered that there had been intelligent creatures in the deep past of that world that then went extinct, who had altered their world while they were around as much as we have, we'd probably select it as the #1 dividing line in the geological record for that planet. And not just for intelligence-centric reasons. It would be a logical way to segment it. For example, you're gonna have long-lived synthetic isotopes in the layers above, and not in the layers below.
I've heard us described as the Anthropocine Extinction
https://www.nhm.ac.uk/discover/what-is-the-anthropocene.html
..., global warming.
But in all seriousness, do humans alter the Earth's surface more than e.g., insects or worms do? Has anybody quantified this?
(Or, alternatively, what happened would be completely obvious, but I still can imagine our scientific community divided over this and some convoluted explanation.)
If we're talking about the ones stored in museum vaults somewhere- then future species will think the hominids coexisted with those giant avians, possibly as their supplicants or praetorians.
Even if all CO2 initiated climate change halted and we magically pulled all the excess carbon out of the atmosphere, there would still be a stark and unambiguous geological marker of our presence in the form of plastics and radioactive material. The article points that out.
The rise, of ~60m, took place over most of the Earth as the volume of the oceans increased during deglaciation and is dated at 11,650–7000 cal. BP
That's a sea level rise of 13 mm/year, on average. Current seal-level rise estimates are about 4 mm/year, and model projections point to as much as 19 mm/year by 2100. It's certainly comparable. These are however relatively slow processes on the scale of a human lifetime, and one could argue human civilization could adapt to these conditions... at some cost, which might be quite high.
I think we we could be in a rapid transition phase, but the state is still very much close to the old state, opposed to the new state.
I saw a note several years ago (written in opposition to an Anthropocene Epoch) which sketched a fun range of names, contingent on future outcomes. I'm regrettably failing to find it, but something very vaguely like (I'm making these up): from 0k glacial minimum, to late holocene thermal excursion, to holocene thermal maximum, to holocene extinction event, to anthropocene epoch, to post-anthropocene epoch, to end-Quaternary mass extinction.
My fuzzy understanding is one pro-Epoch argument is that projections exceed past Holocene variance, there's existing global stratigraphic signals, and it's ok that those events are spread out in time, as that's been the case at other boundaries. And one anti-Epoch argument is that while the Great Acceleration makes a fine event signal, human impacts so precede it (eg late pleistocene megafauna extinction), that it makes a poor epoch divider.
Sci-hub didn't have the TFA-linked paper. :/ Here's a recent "pro" paper[1], rich in detail. And a recent anti[2]. [1] https://repository.si.edu/bitstream/handle/10088/114765/Scot... [2] https://anthroecology.org/wp-content/uploads/2022/03/gibbard...
Also seems a rehash of this: https://www.nature.com/articles/519144a from some years back.
> Formalizing the Anthropocene would unite efforts to study people’s influence on Earth’s systems, in fields including climatology and geology, researchers say. Transitioning to a new epoch might also coax policymakers to take into account the impact of humans on the environment during decision-making.
Ah, it's purely political.
I think this is how the human race will die: a bunch of rich assholes grabbing what ever they can at the expense of the rest of humanity as a bunch of people try to stop it, meanwhile the remaining bulk of humanity is on the sidelines saying shit like "Ah, it's purely political"
We are both being snarky here so drop the holier than thou.
One of the paleontologists quoted in the article describes it perfectly:
> “There is no geologic record of tomorrow,” she says.
That's irrefutable.
The very fact that this is being pushed by a group called the "Anthropocene Working Group" is reason enough to be skeptical of the very concept they are pushing. Their agenda is not based on science, but theology.
> “We were starting from scratch,” says Jan Zalasiewicz, a geologist at the University of Leicester who formerly chaired the AWG and remains a voting member. “We had a vague idea about what it might be, [but] we didn’t know what kind of hard evidence would go into it.”
Again, not science. In fact, that's the antithesis.
Here's a long recent paper with overlapping authors: "Epochs, events and episodes: Marking the geological impact of humans" https://repository.si.edu/bitstream/handle/10088/114765/Scot...