Defining The Anthropocene

[EnolaGaia]

Geologists search for Anthropocene 'golden spike'

The notion that we have entered a new geological age is real and should be formally recognised, according to an international report.

The verdict comes from a panel set up to judge the merits of adding an Anthropocene ("Age of Humans") time segment to the history of the Earth.

The group delivered its preliminary evidence and recommendations on Monday.

It now needs to identify a suitable marker in the environment that epitomises the start of the new phase.

Colin Waters from the British Geological Survey is secretary to the Anthropocene Work Group (AWG). He presented the progress report to the 35th International Geological Congress in South Africa.

"This is an update on where we are in our discussions," he told BBC News.

"We've got to a point where we've listed what we think the Anthropocene means to us as a working group.

"The majority of us think it is real; that there is clearly something happening; that there are clearly signals in the environment that are recognisable and make the Anthropocene a distinct unit; and the majority of us think it would be justified to formally recognise it.

"That doesn't mean it will be formalised, but we're going to go through the procedure of putting in a submission."

The hunt is now on for a "golden spike", as it is known - the marker that scientists can point to years hence - perhaps millions of years hence - and say, "There! That's the start of the Anthropocene Epoch."

And it would likely be an "epoch", said Dr Waters, meaning the current phase of Earth history known as the Holocene has terminated. We would, however, remain within the Quaternary Period and the Cenozoic Era, which are higher rankings in the division of time.

Ten members of the 35-strong working group believe the best spike will probably be plutonium fallout from bomb tests in the 1950s, to be found in marine or lake sediments, ice layers or perhaps even speleothems (stalagmites and stalactites).

Others on the panel, however, think there could be better spikes than the radionuclide. Counter-proposals include remnant plastics or some kind of carbon signature that signifies the rapid rise in CO2 emissions.

Nonetheless, a clear majority of group members (28 of them) accept that whichever marker is chosen, it should reflect events on Earth around the 1950s. ...

Full Story: http://www.bbc.com/news/science-environment-37200489

 

[rynner2]

Full Story: http://www.bbc.com/news/science-environment-37200489

I've been posting on this topic for some time now: my latest was yesterday,
http://forum.forteantimes.com/index...he-real-apocalypse.39958/page-25#post-1611766

 

[EnolaGaia]

I've been posting on this topic for some time now: my latest was yesterday,
http://forum.forteantimes.com/index...he-real-apocalypse.39958/page-25#post-1611766

Yes ... There are several references to the general notion of an 'Anthropocene' era scattered throughout the FTMB - all of which are comments proffered on threads dedicated to particular events or trends constituting evidence for claiming such a notion is viable.

I established this thread to focus on the formal definition / delineation of such a period, now that the 'official' process is underway.

( ... as if 'focus' counts for much around here ... )

 

[Frideswide]

( ... as if 'focus' counts for much around here ... )

what is a focus and would it like biscuits?

However, seriously this is a really good thread! Rynner - do any of your links suggest a definition?

 

[EnolaGaia]

What I find interesting (with respect to the originally-cited news story) are the shifts involved in moving from a casually espoused version of what an Anthropocene age might connote here and now to a formal specification for how archaeologists / paleontologists in the far future are supposed to correlate findings with a standardized geological time chart.

Up to now, the calls for an Anthropocene tend to hinge on recent global trends (most particularly climate change) for which we humans are purportedly to blame. The earth is a dynamic milieu, and something that looms large today may end up being no more than a transient blip in the overall geological record.

The scientists / academics in the working group are grappling with the fascinating issue of what evidence may remain (after some thousands of years' additional time ... ) that one could reliably use to peg the timeframe 'when humans began screwing with the world overall'. Such long-term evidence may have little ongoing or direct relationship with the short-term impacts on which we may concentrate now.

For example ... Let's say the ice caps melt and the oceans rise. "Big deal," says the future paleontologist, "It's happened many times before. There's nothing unique about what happened. My concern is correlating this non-unique event with something else unique enough to clearly indicate when it happened."

 

[Monstrosa]

The presence of plastic nano/micro particles in sediment and the formation of "stones" from plastics?

 

[rynner2]

what is a focus and would it like biscuits?

However, seriously this is a really good thread! Rynner - do any of your links suggest a definition?

Probably most of them! People don't suddenly start talking about the anthropocene without having some idea of what it means.

"Well, I'm getting into the Anthropocene.."
"What's that?"
"I don't really know, but it's a cool word, with four syllables, and I just love the THROP in the middle!"

 

[EnolaGaia]

The presence of plastic nano/micro particles in sediment and the formation of "stones" from plastics?

That's one of the 'contenders' for canonical signs of the Anthropocene's beginning.

An article providing a more detailed overview of the currently nominated signs is now available at:

http://www.smithsonianmag.com/science-nature/where-world-anthropocene-180960241/

The signs aren't mutually exclusive, of course. If one among the nominees is to be designated the paradigmatic or #1 sign, my money's on the plutonium radionuclides.

 

[Frideswide]

"Well, I'm getting into the Anthropocene.."
"What's that?"
"I don't really know, but it's a cool word, with four syllables, and I just love the THROP in the middle!"

have you bugged my phone? AGAIN?

xxx

 

[JamesWhitehead]

Manmade Crystals Which May Define a New Geological Epoch.

 

[skinny]

my money's on the plutonium radionuclides.

Just heard Norm C back this stance. Said the Anthropocene epoch began at the moment nuclear technologies had been developed with the capacity to wipe out all life on earth.

I'd posit a step back a bit with the discovery of gunpowder or the development of mechanical combustion.

 

[EnolaGaia]

Here's a new angle on delineating the Anthropocene (or whatever equivalent is eventually decided ... ). The rise of humans correlates with a massive shrinkage in the demographics of mammal corpses serving as future fossils-in-waiting. This shift will probably serve as a "corpse signal" that will be the hallmark for the transition.

Scientists Argue a 'Corpse Signal' Will Be Left in The Fossil Record of Our Time

Today, the vast majority of scientists agree that humans are causing unprecedented changes to our planet. Yet whether that warrants delineating an entirely new epoch is something geologists continue to disagree on.

Some think the impact of humans is now so great, it exceeds the natural processes of the Holocene, while others argue there's no clear marker in the geological record of the age of humans - the so-called Anthropocene.

Palaeontologists Roy Plotnick and Karen Koy fall in the former category, and they think our fossil record is a dead give-away. In a new paper, the pair argue that in the far future - say, a hundred thousand years from now - fossils of our age will point unmistakably towards humans.

Rather morbidly, they call it the "corpse signal", and it's entirely our fault. Since humans have been on this Earth, the total biomass of wild mammals has fallen by as much as 65 percent; at the same time, the overall biomass of mammals has quadrupled.

The main reason for this tip of the scales is a huge and continuous growth in livestock and humans. This suggests that today, cows, pigs and chickens are far more likely to become "potential fossils".

Throw in domestic pets, like the worldwide dog population of 900 million and the 100 million feral cats, and wild mammals stand even less of a shot.

"The chance of a wild animal becoming part of the fossil record has become very small," says earth and environmental scientist Plotnick from the University of Illinois at Chicago.

"Instead, the future mammal record will be mostly cows, pigs, sheep, goats, dogs, cats, etc., and people themselves." ...

FULL STORY: https://www.sciencealert.com/scient...unmistakable-in-the-fossil-record-of-our-time

 

[Kondoru]

Anyway, geologic marker...what about sea glass?

She picked up so much of the stuff, none left in the gravel beds