Support the Arctic Sea Ice Forum and Blog

Author Topic: Early Anthropocene  (Read 67073 times)

Pmt111500

  • Guest
Early Anthropocene
« on: May 07, 2014, 09:23:06 AM »
Ruddiman & al new article
http://anr.sagepub.com/content/early/2014/02/06/2053019614529263.full.pdf+html

While the wide community of Geologists is considering adopting the anthropocene as starting from 1950 (f.e. rise in plutonium amounts due atmospheric nuclear tests, http://www.independent.co.uk/news/science/the-age-of-anthropocene-was-1950-the-year-human-activity-began-to-leave-an-indelible-mark-on-the-geology-of-earth-9321344.html) Ruddiman et al. is looking deeper in Holocene (imho an obsolete definition, rather this could later be seen as the transition to the anthropocene) to see how it compares to previous interglacials, finding, among other things, that approximately 5950 years ago (would be, by happenstance, very near 4004 BC  ;)) CO2-levels in Holocene start to deviate from those of earlier interglacials.

See for yourself


Gray-Wolf

  • Grease ice
  • Posts: 948
    • View Profile
  • Liked: 131
  • Likes Given: 458
Re: Early Anthropocene
« Reply #1 on: May 07, 2014, 10:34:52 AM »
Such papers do seem to inflame the faux sceptics somewhat as it shows just how human manipulation of the environment brings real consequences with it.

In the UK we see evidence of 'burning' at Flagg Fen which is supposed to have encouraged new reed growth along portions of the Fen ( wetland) making it easier to hunt ( both attract to the new growth and stalk) Deer and other large herbivores.

We also see the loss of all of our upland forests ( now moorland) for grazing and agriculture.

When the planet saw the move to agriculture we must expect alteration to our carbon cycle with the loss of forest replaced with monoculture and scrub.

Some folk go as far as to suggest that even without the move to a fossil fuel we would have altered the world enough to offset the drop into the next glacial period?
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

jai mitchell

  • Nilas ice
  • Posts: 2357
    • View Profile
  • Liked: 207
  • Likes Given: 60
Re: Early Anthropocene
« Reply #2 on: May 07, 2014, 06:45:31 PM »
What the paper doesn't consider is that periodic volcanic eruptions in a world without Neolithic agriculture would have plunged into another ice age subsequent to the massive 1258 volcanic eruption.

after a decade of ice sheet accumulation and subsequent albedo increase, vast portions of north America would be made uninhabitable if methane was still 450ppb and CO2 was 245ppm.

http://www.wired.com/2012/02/the-mysterious-missing-eruption-of-1258-a-d/

in this view, then, the date of the anthropocene should be at least 1250, when we prevented this ice age driven negative feedback.
Haiku of Futures Passed
My "burning embers"
are not tri-color bar graphs
+3C today

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #3 on: May 08, 2014, 12:47:12 AM »
Alternately, if one were to consider the relationship of the industrial revolution to fossil fuel consumption, then from the attached Keeling CO2 plot, one might be tempted to take circa 1750 as the start of the anthropocene.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Pmt111500

  • Guest
Re: Early Anthropocene
« Reply #4 on: May 08, 2014, 06:00:42 AM »
Good points, all. Then there's the megafauna extinction too, that could be used, if overkill hypothesis is the correct one, but to give it a firm date is a harder thing to do (f.e. google Wrangel island mammoth). I had (temporarily) forgotten the 1258 eruption when reading the article, jai mitchell may well have a great point. So agricultulre would have saved many in that case, but the use of fossils threatens many (f.e. extra lead, mercury and arsenic in atypical places to keep GW out of this). but I think it can be agreed that Anthropocene has started by now.

(modified to add) the Roman Iron smelting, or the invention of bronze, the first material humans made not occurring naturally.
« Last Edit: May 08, 2014, 06:25:45 AM by Pmt111500 »

Shared Humanity

  • Guest
Re: Early Anthropocene
« Reply #5 on: May 08, 2014, 02:21:42 PM »
Since humans are uniquely capable of altering their environment and anthropological evidence shows this was accomplished back thousands of years, I would suggest that simply looking at population trends might help us put a stake in the ground.

This 1st graph might suggest that a rapid growth in population that can be seen starting somewhere during the last millennium would be a good point. This point could be either post black death or prior to the black death. If you take this rapid drop in world population out, I believe the point for the start of the Anthropocene could be around 1000AD.

I, however, believe this 1st chart is misleading and that it hides the point at which exponential growth in population began and the resulting impact we've had on the world's environment.

If you look at the 2nd chart, it is clear that exponential growth had already begun by 500BC. Armed with this, looking back at the 1st chart, I would argue that exponential population growth and, thus, the Anthropocene began between 7000BC and 5000BC or the beginning of the New Stone Age.

icefest

  • Frazil ice
  • Posts: 258
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Early Anthropocene
« Reply #6 on: May 08, 2014, 04:07:03 PM »
As an adjunct to SHs post, here is world pop on a log-linear scale.

4000BC is where human pop started growing exponentially.

Open other end.

wili

  • Young ice
  • Posts: 3342
    • View Profile
  • Liked: 602
  • Likes Given: 409
Re: Early Anthropocene
« Reply #7 on: May 08, 2014, 06:10:27 PM »
Interesting. That's about the time of what is sometimes knows as the "Second Agricultural Revolution" started (~6000-4000 BC; the term was, I believe, coined by Andrew Sheratt). Domesticated animals started being used for a wider range of products:

--wool from sheep,
--not just milk but butter and cheese-like products from milk-bearing animals.
--Draft animals, especially cattle, also started being used more widely, not only to plow fields, but to draw
--wheeled vehicles to bring agricultural produce to more distant populations (beginning of what has become our car/truck culture.)
--This is also about then time that the horse was probably first domesticated.
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

crandles

  • Young ice
  • Posts: 3379
    • View Profile
  • Liked: 239
  • Likes Given: 81
Re: Early Anthropocene
« Reply #8 on: May 08, 2014, 06:35:39 PM »
Anthropocene is meant to be a geologic time period. So AIUI for consistency it should be possible to tell the difference by looking at todays ground in a few million years.

I am not sure such a future archaeologist would be able to tell that human populations levels were beginning to rise around 6000-4000BC nor the CO2 levels beginning to rise unless you count looking at air bubbles in ice cores and even if you do I am not sure any of todays ice will survive to be examinable.

So to me, these do seem more prelude to the change rather than beginning of anthropocene. (Not that I am an expert at all.)

Species reduction might be evident sufficiently before 1950?

jai mitchell

  • Nilas ice
  • Posts: 2357
    • View Profile
  • Liked: 207
  • Likes Given: 60
Re: Early Anthropocene
« Reply #9 on: May 08, 2014, 07:38:23 PM »
So far the basis of the Anthropocene seems to be things that can be directly related to human activities:

  • human population
  • carbon dioxide emissions
  • temperature


However, I think that there is another way to look at it.  What if the Holocene IS the Anthropocene?

Human beings developed their first settled societies around 10,000 B.C. so we could show that organized human society started at the beginning of the Holocene.

In this view, then the next epoch would not be the Anthropocene,

it would be based on humanity's effect of the planet's other residents.

http://www.nap.edu/openbook.php?record_id=12501&page=R3

In the Light of Evolution
Volume II: Biodiversity and Extinction
JOHN C. AVISE, STEPHEN P. HUBBELL, and FRANCISCO J. AYALA, Editors
NATIONAL ACADEMY OF SCIENCES THE NATIONAL ACADEMIES

Quote
Many scientists argue that we are either entering or in the midst of the sixth great mass extinction. Intense human pressure, both direct and indirect, is having profound effects on natural environments. The amphibians—frogs, salamanders, and caecilians—may be the only major group currently at risk globally. A detailed worldwide assessment and subsequent updates show that one-third or more of the 6,300 species are threatened with extinction. This trend is likely to accelerate because most amphibians occur in the tropics and have small geographic ranges that make them susceptible to extinction.

Since this extinction event has the potential to rival the mass extinction events that have defined previous the periods in the fossil record, then the Anthropocene started at 12,000 BCE and ended in 1978.



The new period we have entered isn't the anthropocene, it is the deleocene.

Quote
The Latin phrase for Wipe Out is deleo. The Latin phrase deleo is defined as (deletum ) to destroy, wipe out, erase.
« Last Edit: May 08, 2014, 11:17:16 PM by jai mitchell »
Haiku of Futures Passed
My "burning embers"
are not tri-color bar graphs
+3C today

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #10 on: May 08, 2014, 10:50:33 PM »
All,

The following link leads to a Wikipedia article regarding the definition of the Anthropocene, including the fact that: "Steps are being taken by independent working groups of scientists from various geological societies to determine whether the Anthropocene will be formally accepted into the Geological Time Scale."

http://en.wikipedia.org/wiki/Anthropocene

The article discuss all of the points presented in this thread, and others, and points out that while there is as yet no final determination as to when the Anthropocene begins, it is most commonly assumed to begin at the beginning of the Industrial Revolution (but not necessarily).

Best,
ASLR
« Last Edit: May 09, 2014, 12:28:45 AM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: Early Anthropocene
« Reply #11 on: May 09, 2014, 12:08:54 AM »
This is some general info about geological timescales collected from around the web

Within the field of Geochronology (the science of determining the age of rocks, fossils, and sediments) there are five time spans, all of which spans over millions of years;
  • Eon (Eonothem)
  • Era (Erathem)
  • Period (System)
  • Epoch (Series)
  • Age (Stage)
The current epoch is the Holocene which has only lasted for 11700 years and are thus only subdivided into "chrons", which is not a properly defined and recognized geological timescale, as well as historic periods. The current period, Quaternary, has also just begun, that means it has so far lasted for 2,588 million years (periods usually lasts 30-60 million years) and includes only one epoch in adition to holocene. Quaternary is furthermore a subdivision of the Cenozoic Era (Kainos meaning "new" and Zoe meaning "life" in greek), that is the "age of mammals" which has lasted since the extinction of the dinosaurs (65 million years ago).

some links
http://en.wikipedia.org/wiki/Geochronology
http://en.wikipedia.org/wiki/Holocene
http://www.geosociety.org/science/timescale/

Shared Humanity

  • Guest
Re: Early Anthropocene
« Reply #12 on: May 09, 2014, 04:55:15 PM »
So far the basis of the Anthropocene seems to be things that can be directly related to human activities:

  • human population
  • carbon dioxide emissions
  • temperature


What if the Holocene IS the Anthropocene?

The new period we have entered isn't the anthropocene, it is the deleocene.

Quote
The Latin phrase for Wipe Out is deleo. The Latin phrase deleo is defined as (deletum ) to destroy, wipe out, erase.

I believe you have hit the nail on the head. If we look at  humanity's impact on extinction rates, then the Holocene is, in fact, the Anthropocene. While I certainly enjoyed your argument for our now entering a new age "the Deleocene" (I saw what you did there.), I believe we are merely accelerating into a massive extinction event and therefore are merely in the early stages of the Anthropocene.

This would also address Crandle's concern that, in distinguishing an age, "it should be possible to tell the difference by looking at today's ground in a few million years." I believe the rapidly approaching mass extinction will allow for future scientists to do just that.

The only question remaining for me is whether  the fossil record will show a Permian sized extinction event or something more like the event 65 million years ago.

Is humankind more of an asteroid or massive basaltic lava eruption?   :-\
« Last Edit: May 09, 2014, 05:32:16 PM by Shared Humanity »

ccgwebmaster

  • Nilas ice
  • Posts: 1085
  • Civilisation collapse - what are you doing?
    • View Profile
    • CCG Website
  • Liked: 2
  • Likes Given: 0
Re: Early Anthropocene
« Reply #13 on: May 09, 2014, 06:10:32 PM »
This would also address Crandle's concern that, in distinguishing an age, "it should be possible to tell the difference by looking at today's ground in a few million years." I believe the rapidly approaching mass extinction will allow for future scientists to do just that.

To tell the difference from the ground just look for a few obvious things at the start:
- a particular signature of radioactive isotopic fallout, now used to verify the age of wines produced before above ground nuclear testing
- deposition of plastic particles

Actually there's probably plenty of other forms of contamination one could look at to measure the approximate start of this episode of earth history with reasonable accuracy when talking about geological timescales.

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: Early Anthropocene
« Reply #14 on: May 09, 2014, 07:18:32 PM »

The only question remaining for me is whether  the fossil record will show a Permian sized extinction event or something more like the event 65 million years ago.

Is humankind more of an asteroid or massive basaltic lava eruption?   :-\


I believe, for several reasons, that the changes we are currently seeing constitutes to much more than a change in epoch. First, as SH says, there is going to be an extinction event of massive propotions (I'm confident that a double digit percentage of Earths species are going to be driven to extinction), this will most probably constitute to a change in period or perhaps even a change in era, as is usually the case of large extinction events. Also, in my oppinion, the earth will from this point on likely be dominated by the most intelligent species, even if the human race dies of, there are many close relatives to humans, as well as other species out there, capable of developing human intelligence within a geological short period of time, thus likely stalking the earth with human-like civilisations on a regular basis. This is of course unless the extinction event currently ongoing, become even bigger than the permian one, thus eliminating every larger land animal, and bird.

Either way, an epoch, or age, called Anthropocene, should as I see it be the first of a new period or era, as both the introdution of human level intelligence and the mass extinction likely to be caused by our presence, is one of the biggest events in the history of the earth. The existence of holocene seems to be a bad idea whatever happens in the future, as it should be a part of the Anthropocene, or alternatively the end of the Pleistocene
« Last Edit: May 09, 2014, 08:58:00 PM by Rubikscube »

Laurent

  • Young ice
  • Posts: 2546
    • View Profile
  • Liked: 13
  • Likes Given: 50
Re: Early Anthropocene
« Reply #15 on: August 13, 2014, 10:00:54 PM »

Laurent

  • Young ice
  • Posts: 2546
    • View Profile
  • Liked: 13
  • Likes Given: 50
Re: Early Anthropocene
« Reply #16 on: October 17, 2014, 09:47:41 AM »

Laurent

  • Young ice
  • Posts: 2546
    • View Profile
  • Liked: 13
  • Likes Given: 50
Re: Early Anthropocene
« Reply #17 on: October 17, 2014, 01:35:30 PM »

Pmt111500

  • Guest
Re: Early Anthropocene
« Reply #18 on: January 17, 2015, 10:54:55 AM »
Group proposes the Antrhopocene to begin with the Nuclear Age, that could be in my opinion to be rounded to winter solstice 1950 in order to still use the BP-calendar of geology. That would make this date 27th of January, 65 AE (Anthropocene Era).
http://www.sciencedirect.com/science/article/pii/S1040618214009136

There's though an interesting proposal on the comments here
http://phys.org/news/2015-01-anthropocene-nuclear-age.html
that states the year when mankind first overshoot the NPP (natural primary production) should be taken as the starting point. I know this is sometime in the 1970s or latest early 1980s but what is the exact year? Anybody know?

If we pick a date, say 4000BC, because of Ruddimans' studies, as the start date, do we at the same time diss the many good things (=larger food production) the Agriculture has provided us, and wouldn't we be close to ice age currently if those people back in ~4004BC or thereabouts wouldn't have cleared the forests in Fertile Crescent and Mediterranean? 8) ::) 8)

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #19 on: March 11, 2015, 11:18:35 PM »
The linked reference recommends that the Anthropocence  be defined to begin either in 1610 or 1964:

Simon L. Lewis & Mark A. Maslin, (2015), "Defining the Anthropocene", Nature, Volume: 519, Pages: 171–180, doi:10.1038/nature14258


http://www.nature.com/nature/journal/v519/n7542/full/nature14258.html

http://www.nature.com/articles/nature14258.epdf?referrer_access_token=_PLYMXO_7pZvnC9psaNnzdRgN0jAjWel9jnR3ZoTv0NY9hwYLWp7R0oJ40dNLmwRNIWFwvx03EKJH0zM6Mp4JjECKgKbSWeNKNLccYnwNeuxIjogv-rur0GFEzyxrx_FxFErrX7NOKDqp3C93-HB8Um8CT1IsrZ6isM6iYlcM9Kp8E17tWxJ0XzRw-RhTyAn2F80gWU5U-JsIcZGtm014g%3D%3D&tracking_referrer=www.newyorker.com


Abstract: "Time is divided by geologists according to marked shifts in Earth’s state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Here we review the historical genesis of the idea and assess anthropogenic signatures in the geological record against the formal requirements for the recognition of a new epoch. The evidence suggests that of the various proposed dates two do appear to conform to the criteria to mark the beginning of the Anthropocene: 1610 and 1964. The formal establishment of an Anthropocene Epoch would mark a fundamental change in the relationship between humans and the Earth system."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Anne

  • Grease ice
  • Posts: 531
    • View Profile
  • Liked: 13
  • Likes Given: 2
Re: Early Anthropocene
« Reply #20 on: April 04, 2015, 12:38:51 PM »
Something that had escaped me until now is that the Lewis and Maslin paper cited by ASLR above posits that the Little Ice Age was anthropogenic. The hypothesis is that the arrival of Europeans in the New World led to massive depopulation as they brought their diseases with them. Slavery had a similarly damaging effect on African populations and agriculture. The consequent loss of farmland to afforestation led to a decrease in atmospheric CO2.
Quote
Lewis and Maslin reject this radionuclide spike because it is not tied to a "world-changing event"—at least not yet—although it is a clear signal in the rock. On the other hand, their Orbis spike in 1610 reflects both the most recent CO2 nadir as well as the redistribution of plants and animals around the world around that time, a literal changing of the world.
 
Much like the golden spike that marks the end of the dinosaurs, the proposed Orbis spike itself would be tied to the low point of atmospheric CO2 concentrations around 1610, as recorded in ice cores, where tiny trapped bubbles betray past atmospheres. Further geologic evidence will come from the appearance of corn pollen in sediment cores taken in Europe and Asia at that time, among other indicators that will complement the CO2 record. Therefore, scientists looking at ice cores, mud or even rock will find this epochal shift in the future.
 
The CO2 drop coincides with what climatologists call the little ice age. That cooling event may have been tied to regenerated forests and other plants growing on some 50 million hectares of land abandoned by humans after the mass death brought on by disease and warfare, Lewis and Maslin suggest. And it wasn't just the death of millions of Americans, as many as three quarters of the entire population of two continents. The enslavement (or death) of as many as 28 million Africans for labor in the new lands also may have added to the climate impact. The population of the regions of northwestern Africa most affected by the slave trade did not begin to recover until the end of the 19th century. In other words, from 1600 to 1900 or so swathes of that region may have been regrowing forest, enough to draw down CO2, just like the regrowth of the Amazon and the great North American woods, although this hypothesis remains in some dispute.
 
(Quoted from Scientific American article here as I couldn't cut and paste from the Nature article though it is free to view.)

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #21 on: July 05, 2015, 07:42:26 PM »
I start the following series of posts (in this thread) by noting that I now concur with jai (see Reply #9) that it would be most rational to replace the Holocene Epoch with the name Anthropocene and that I also agree with Rubikscube (see Replies # 11 & 14) that the Anthropocene should be declared an Era instead of an Epoch.  I will cite my reasons for supporting this definition of the Anthropocene Era (or Epoch) later, but first I would like to elaborate on some of the recent debate for other dates/definitions for the Anthropocene.

First, Wikipedia offers the following commentary regarding a definition for the Anthropocene: "In January 2015, 26 of the 38 members of the International Anthropocene Working Group published a paper suggesting that July 16, 1945 was the starting point of the proposed new epoch. However, a significant minority supports one of several alternative dates.  In March 2015, another paper suggested either 1610 or 1964 could be the beginning of Anthropocene. The Anthropocene Working Group plans to meet in 2016 to submit evidence and decide whether the Anthropocene is a true geologic epoch."

See also:
http://quaternary.stratigraphy.org/workinggroups/anthropocene/
http://www.newsweek.com/did-anthropocene-begin-deaths-50-million-native-americans-313319
http://www.vox.com/2015/4/2/8335915/anthropocene-debate
http://www.scientificamerican.com/article/did-the-anthropocene-begin-in-1950-or-50-000-years-ago/

I acknowledge that the "International Anthropogenic Working Group" will determine the formal definition of the Anthropocene Epoch (or Era) in 2016; and while further acknowledge that different scientific and socio-economic disciplines will likely have various definition of different relevant Ages/Periods/Eras (Neolithic Revolution, Age of Discovery, Industrial Revolution, Atomic Age, Information Age, etc. etc. etc.).  Nevertheless, I plan to discuss the logic for simply, and entirely, re-defining the Holocene Epoch as the Anthropocene Era (or Epoch).  By this line of logic (see Walker et al 2009, below), the Greenland NGRIP ice core would place the beginning of the Anthropocene Epoch at 9,700 BCE (or 11,700 years before the year 2000) +/- 99 years, and would continue until mankind stops having a dominant impact on the various Earth Systems.
Roughly speaking, I propose the line of logic that the Younger Dryas came to an unnaturally abrupt end associated with a marked change in atmospheric circulation regime (accompanied a temperature rise in Greenland of 10 +/4 C); which was triggered when the cumulative effect of the multi-millennial long anthropogenically induced Mega Fauna Extinction (here postulated to have reached a critical condition during the Younger Dryas when the last remaining Mega Fauna that where already stressed by anthropogenic impact, succumbed to cold snap) induced a tipping point in the atmospheric circulation pattern via changes in the biosphere (e.g. albedo changes as shrubs previously suppressed by high-latitude mega fauna grew above the on land snow cover, etc).

Walker, M.; Johnsen, S.; Rasmussen, S. O.; Popp, T.; Steffensen, J.-P.; Gibbard, P.; Hoek, W.; Lowe, J.; Andrews, J.; Bjo; Cwynar, L. C.; Hughen, K.; Kershaw, P.; Kromer, B.; Litt, T.; Lowe, D. J.; Nakagawa, T.; Newnham, R.; Schwander, J. (2009). "Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records" (PDF). J. Quaternary Sci. 24: 3–17. doi:10.1002/jqs.1227

http://onlinelibrary.wiley.com/doi/10.1002/jqs.1227/abstract;jsessionid=4642F856F01B3EE7C526138127CEE75F.f01t01
http://onlinelibrary.wiley.com/doi/10.1002/jqs.1227/epdf

Abstract: "The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ18O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi-parameter annual layer counting provides an age of 11 700 calendar yr b2 k (before AD 2000) for the base of the Holocene, with a maximum counting error of 99 yr. A proposal that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene–Holocene boundary have also been recognised."

Extract: "These various data sources reflect a marked change in atmospheric circulation regime accompanied by a temperature rise, probably of the order of 10 +/-4oC, at the onset of the Holocene …"

Making a distinction between the Holocene Extinction and the Anthropocene seems to me that it would be short sighted (on the part of the International Anthropocene Working Group) as the Holocene Extinction is clearly related to human activities as it’s either eight to 100 times up to about 100 to 1,000 times the normal rate of extinction among species.
See also:
http://www.huffingtonpost.co.uk/2015/06/20/earth-mass-extinction-event-scientists-warn-new-study_n_7627488.html
http://advances.sciencemag.org/content/1/5/e1400253

I conclude this post with a few Wikipedia links & abstracts regarding: (a) The Sixth Extinction; (b) The Holocene Extinction; and (c) the most recent series of megafaunal extinction pulses.
http://en.wikipedia.org/wiki/The_Sixth_Extinction_(book)

Extract: "The Sixth Extinction: An Unnatural History is a 2014 nonfiction book written by Elizabeth Kolbert and published by Henry Holt & Company. The book covers past mass extinctions and demonstrates that the earth and humans are in the midst of a "sixth" mass extinction. She chronicles previous mass species extinction events, as well as specific species extinguished by humans thousands of years ago, such as the great auk; and she includes the accelerated widespread extinction of many species during our present time. Kolbert also describes prehistoric and historic ecologies surrounding prior and near-present species extinguishing events. The author received the Pulitzer Prize for General Non-Fiction for the book in 2015.



Human behavior disrupts earth's balanced and interconnected systems "putting our own survival in danger." Consequently, the earth systems currently affected are: the global atmosphere, the water cycle, the ocean's thermal or heat absorption, ocean acidity and coral reefs, soil moisture and drought conditions, plant destruction by pests or non-indigenous fauna or heat stress, heat regulation by the earth's ice, and so on.
The human species contributes to this disruption - even without intending to - because of our innate capabilities to alter the planet at this stage of our cultural evolution; for instance, we now have the ability to harness energy from beneath the earth's surface. Homo sapiens also has the ability to adapt relatively quickly to almost any environment on this planet's surface. Other species, however, have a hard time relocating to new, suitable habitats. They are unable to migrate ahead of current rapid ecological changes, or are hampered by artificial barriers such as roadways, cityscapes, and suburban sprawl, which cause increased discontinuity between viable habitats throughout world.


Kolbert states that human activity has transformed between a third and a half of land surface on the planet. We have damned most of the major rivers of world, increased levels of nitrogen than can be fixed naturally by terrestrial ecosystem, used more than half of the world’s readily accessible freshwater run-off, removed more than one third of the primary producers of the oceans’ coastal waters, and changed the composition of the atmosphere by deforestation and fossil fuel combustion."


http://en.wikipedia.org/wiki/Holocene_extinction
Extract: "The Holocene extinction, sometimes called the Sixth Extinction, is a name proposed to describe the currently ongoing extinction event of species during the present Holocene epoch (since around 10,000 BCE) mainly due to human activity."

http://en.wikipedia.org/wiki/Megafauna
Extract: "However, this extinction pulse near the end of the Pleistocene was just one of a series of megafaunal extinction pulses that have occurred during the last 50,000 years over much of the Earth's surface, with Africa and southern Asia (where the local megafauna had a chance to evolve alongside modern humans) being largely spared. The latter areas did suffer a gradual attrition of megafauna, particularly of the slower-moving species (a class of vulnerable megafauna epitomized by giant tortoises), over the last several million years.
Outside the mainland of Afro-Eurasia, these megafaunal extinctions followed a highly distinctive landmass-by-landmass pattern that closely parallels the spread of humans into previously uninhabited regions of the world, and which shows no correlation with climatic history (which can be visualized with plots over recent geological time periods of climate markers such as marine oxygen isotopes or atmospheric carbon dioxide levels).  Australia was struck first around 45,000 years ago, followed by Tasmania about 41,000 years ago (after formation of a land bridge to Australia about 43,000 years ago), Japan apparently about 30,000 years ago, North America 13,000 years ago, South America about 500 years later, Cyprus 10,000 years ago, the Antilles 6000 years ago, New Caledonia and nearby islands 3000 years ago, Madagascar 2000 years ago, New Zealand 700 years ago, the Mascarenes 400 years ago, and the Commander Islands 250 years ago."

(also see that attached image from this reference showing a timeline of human migration; which correlates tightly with the timeline of megafauna extinction)
 
See also:
http://en.wikipedia.org/wiki/Human
http://www.thefreedictionary.com/Homo+sapiens+sapiens

Again, my definition of the beginning of the Anthropocene is the point when human control of tools cause the global Earth Systems to be changed beyond natural variation.  This first requires human (homo sapiens sapiens) population to be reasonably dispersed around the world (i.e. South America was populated by 10 kya); and second to have unbalanced some key Earth Systems (i.e. megafaunal extinctions & associated changes in the megafaunal habits due to their loss, which for practical purposes occurred 10 kya in South America).  Thus it is my recommendation that the entire Holocene be renamed as the Anthropocene, as it is during this period that the Holocene Extinction/Sixth Extinction has been accelerating.
« Last Edit: July 05, 2015, 07:51:38 PM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #22 on: July 05, 2015, 07:59:59 PM »
Further to my Reply #19 about the March 2015 reference by Lewis & Maslin; which discusses the use of various Global Stratotype Section and Points (GSSPs), also known as a “golden spikes”, to possibly define the Anthropocene;

Lewis, S. L.; Maslin, M. A. (12 March 2015). "Defining the Anthropocene". Nature 519: 171–180. doi:10.1038/nature14258

http://www.nature.com/nature/journal/v519/n7542/full/nature14258.html
https://eorder.sheridan.com/3_0/app/orders/4609/article.php#171

(Note the four attached images are from this open access reference & they provide background information relevant to different possible definitions for the Anthropocene)

See also:
http://theconversation.com/anthropocene-began-with-species-exchange-between-old-and-new-worlds-38674
or
http://www.iflscience.com/environment/anthropocene-began-species-exchange-between-old-and-new-worlds
Extract: "Defining the beginning of the Anthropocene as a formal geologic unit of time requires two requirements to be met. First, that there is evidence of long-term changes to the Earth as a global system. Second, that there is a marker of a global event that can be dated in layers of rock, sediment from the ocean floor, or ancient glacier ice. This marker is called a Global Stratotype Section and Point (GSSP), also known as a “golden spike”. GSSPs have been used to define geological time for the past 600m years.
In our research we found that most previously proposed Anthropocene start dates, including the earliest detectable human impacts through farming and historic events such as the start of the industrial revolution, should be rejected. They are not based on a globally synchronous markers and may not be permanent changes that could still be seen in a few million years – the time span of a typical epoch.
We found only two GSSP dates that fit. There was the 1610 Orbis (Latin for “world”) spike, when the impacts of the collision of the New and Old Worlds a century earlier were first felt globally. The species exchange between the Old and New Worlds is noted in the fossil record at this time, coupled with a marked drop in atmospheric carbon dioxide, centred on 1610. Then there was the 1964 Bomb Spike, the peak in radionuclide fallout from nuclear weapons testing, which is coincident with the acceleration of very recent global environmental changes.
While both GSSP dates appear to adhere to the criteria for the beginning of the Anthropocene, we suggest that overall, 1610 is the strongest contender.

Nonetheless, the collision of the Old and New Worlds is linked to the industrial revolution. Europe’s annexing of the Americas provided major new imports of agricultural commodities, thereby freeing Western European labour from the land – this, alongside coal, was one of two essential precursors to the industrial revolution. So dating the Anthropocene to 1610, some 150 years prior to the beginning of the industrial revolution, is consistent with the material causes of that turning point in human history."
Also see:
Kenneth Pomeranz The Great Divergence: China, Europe, and the Making of the Modern World Economy (hardback 2000, paperback 2001) ISBN: 9780691090108.

http://press.princeton.edu/titles/6823.html

Extracts: "Pomeranz argues that Europe's nineteenth-century divergence from the Old World owes much to the fortunate location of coal, which substituted for timber. This made Europe's failure to use its land intensively much less of a problem, while allowing growth in energy-intensive industries. Another crucial difference that he notes has to do with trade. Fortuitous global conjunctures made the Americas a greater source of needed primary products for Europe than any Asian periphery. This allowed Northwest Europe to grow dramatically in population, specialize further in manufactures, and remove labor from the land, using increased imports rather than maximizing yields. Together, coal and the New World allowed Europe to grow along resource-intensive, labor-saving paths.
 "The vast international disparity in incomes and standards of living between Western Europe and its offshoots on the one hand, and most of Asia, Africa, and Latin America on the other, is a striking feature of the modern world. Pomeranz's study is an important addition to the literature that challenges elements of every major interpretation of the European take-off."--Choice
"A profoundly though-provoking book which will change the terms of the debate about the origins of capitalism, the rise of the West and the fall of the East."--Jack Goody, Times Higher Education Supplement"

Furthermore, in a follow-on May 2015 reference by Hamilton it is proposed that it is more appropriate to focus on man's impacts on Earth Systems, rather than focusing on "golden spikes" when defining the Anthropocene:
Clive Hamilton (May 1, 2015), "Getting the Anthropocene so wrong", The Anthropocene Review, doi:10.1177/2053019615584974
http://anr.sagepub.com/content/early/2015/04/30/2053019615584974.abstract

Abstract: "Rather than clarifying it, a recent paper by Simon Lewis and Mark Maslin (2015), ‘Defining the Anthropocene’, adds to the confusion about the new epoch. The paper does not recognise that a paradigm shift has occurred, one in which environmental science has been displaced by Earth System science. The story tells of an Anthropocene beginning in 1610. It is not credible, as it is not based on an accurate understanding of the Earth System. In addition, in its determination to find a ‘golden spike’ the paper confuses stratigraphic markers for the epoch itself. It finds a marker when there is no event and ignores an event when it cannot find a marker."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #23 on: July 05, 2015, 08:06:09 PM »
For further elaboration, I cite a couple of recent articles from "The Anthropocene Review":

http://anr.sagepub.com/content/1/1.toc

The first following "The Anthropocene Review" article provides a graphical depiction of key socio-economic & Earth Systems trends of the Anthropocene from 1750 to 2010.  If one wishes to focus on the anthropogenic impacts of both the "Age of Discovery" and the "Industrial Revolution; then these graphs clearly illustrate the rate of acceleration of anthropogenic impacts over a recent 260 year period.

http://anr.sagepub.com/content/2/1/81

Will Steffen et al. (March 2015), “The trajectory of the Anthropocene: The Great Acceleration.” The Anthropocene Review, 81-98; doi: 10.1177/2053019614564785


Abstract: "The ‘Great Acceleration’ graphs, originally published in 2004 to show socio-economic and Earth System trends from 1750 to 2000, have now been updated to 2010. In the graphs of socio-economic trends, where the data permit, the activity of the wealthy (OECD) countries, those countries with emerging economies, and the rest of the world have now been differentiated. The dominant feature of the socio-economic trends is that the economic activity of the human enterprise continues to grow at a rapid rate. However, the differentiated graphs clearly show that strong equity issues are masked by considering global aggregates only. Most of the population growth since 1950 has been in the non-OECD world but the world’s economy (GDP), and hence consumption, is still strongly dominated by the OECD world. The Earth System indicators, in general, continued their long-term, post-industrial rise, although a few, such as atmospheric methane concentration and stratospheric ozone loss, showed a slowing or apparent stabilisation over the past decade. The post-1950 acceleration in the Earth System indicators remains clear. Only beyond the mid-20th century is there clear evidence for fundamental shifts in the state and functioning of the Earth System that are beyond the range of variability of the Holocene and driven by human activities. Thus, of all the candidates for a start date for the Anthropocene, the beginning of the Great Acceleration is by far the most convincing from an Earth System science perspective."

Also, the attached image comes from this first reference.

The second following "The Anthropocene Review" article clarifies that the classic Popperian approach to science (frequently used by climate change deniers) is not well suited for examining a complex Earth System.
Frank Oldfield and Will Steffen (April 2014), "Anthropogenic climate change and the nature of Earth System science", The Anthropocene Review, 1: 70-75, doi:10.1177/2053019613514862
http://anr.sagepub.com/content/1/1/70.full.pdf+html

Abstract: "One of the criticisms made by those sceptical of the majority scientific consensus on climate change and its likely future consequences is that the Earth System science upon which it is based is fundamentally flawed. This contention is challenged here by an outline of the nature of the science needed to make future projections possible. The classic Popperian approach to science, in which potentially refutable hypotheses are defined and tested is not well suited to the challenges posed by an Earth System that is characterised by high degrees of complexity, non-linearity and a lack of definable cause–consequence relationships. A science based on model–data comparisons and interactions is the only effective approach both to increasing our understanding of the Earth System and developing a well substantiated basis for future projections."

Extract: "Finally, alongside the type of ‘projective’ science outlined above lie future scenarios that include alternative pathways for human populations, their activities and the consequences of those activities. These rest on both quantitative science and plausible assumptions of human activity into the future. Whereas the former can be refined and filtered by the application of criteria based on the skill with which they capture current reality and past variations, the latter are not amenable to such rigorous evaluation. They too, though, are vital components of the Earth System and require the engagement of many areas of scholarship beyond those traditionally considered to be within the realm of Earth System science.
In the latest IPCC Summary for Policymakers (2013), these scenarios are portrayed as Representative Concentration Pathways (RCPs) rather than socio-economic scenarios. The only future projection that gives possible cause for complacency is RCP 2.6, which is theoretically possible provided all emission targets are met (van Vuuren et al., 2011). Current national trends, despite past, partial agreements on emission limitation and continuing rhetoric, seem unlikely to come anywhere near to meeting the targets required. In fact, our emissions are currently tracking nearest to RCP 8.5, the highest of the four pathways. The higher emission scenarios are thus much more probable, suggesting that the future does indeed hold challenges that, for much of humanity, will require a mix of mitigation and adaptation that still lies beyond most policy statements at national or international level. Moreover, for the high-end emission scenarios, the rates of change and projected outcomes may lie beyond the adaptive capacity of much of the human population as well as many aspects of Earth System functioning. The bottom line is clear. Denying the relevance and validity of Earth System science is a highly risky, and possibly catastrophic, approach for humanity to take towards its future."

See also:
http://www.sci-news.com/othersciences/anthropology/science-anthropocene-new-geological-epoch-02405.html

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #24 on: July 05, 2015, 08:09:16 PM »
The following linked reference by Prado et al 2015 provides more details about the chronology of the Megafauna Extinction in South America:

José L. Prado, Cayetana Martinez-Maza, María T. Alberdi, (2015), "Megafauna extinction in South America: A new chronology for the Argentine Pampas", Palaeogeography, Palaeoclimatology, Palaeoecology 425 (2015) 41–49


http://www.researchgate.net/profile/Maria_Alberdi/publication/273005788_Megafauna_Extinction_in_South_America_A_new_chronology_for_the_Argentine_Pampas/links/54ff0d790cf2741b69f211ba.pdf
Abstract: "The megafauna extinction in South America was one of the most profound events, with the loss of 50 genera (~83%). Three orders disappeared (Notoungulata, Proboscidea, Litopterna), as did all large xenarthrans, but how this fits into global extinction is uncertain, mainly due to the lack of chronological resolution. In recent years there has been an increase in the number of radiocarbon dating at archeological and paleontological sites, but this information varies greatly from area to area in South America, and few data can be considered to constitute a taxon-date.
The timing of the late Pleistocene extinction in the Pampas is poorly established.  Most taxa only appear in the biostratigraphic context and many reported 14C dates do not meet rigorous criteria for accepting dates, including reports suggesting survival of megafauna into the Holocene. In the present paper, we evaluate the published radiocarbon dates in the pampas and present 20 new radiocarbon dates for paleontological sites in order to establish a more accurate “extinction window” for the key taxa. These new dates are sufficiently robust to assess correspondences among last-appearance records of megafauna, first-appearance records of humans, and the
Younger Dryas to Holocene climatic transition in the Argentine Pampas. These results highlight the need for greater effort in taxa selection for dating."


Caption for the attached image "Fig. 3. Last-appearance dates for megafauna from the Argentine Pampas region, using only robust dates from previous papers and the new dates. The horizontal dashed line indicates a consistent archeological signal. The dotted horizontal line indicates the earliest occupation evidence or minimal human activity. The gray boxes indicate the dates obtained from the literature, and the red line is the average of these. Black boxes indicate the new dates and the green line is the average of these. The blue band denotes the timing of Younger Dryas cooling in Argentine Pampas region (Hajdas et al., 2003; Krohling and Iriondo, 1999). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)"
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #25 on: July 05, 2015, 08:10:55 PM »
The following linked Skeptical Science discusses the correlation between the Younger Dryas and the extinction of the megafauna:

http://www.skepticalscience.com/younger-dryas-recent-research.html
Extract: "Extinctions do not need a single cause. They can have many, direct and indirect. Direct causes that reduce populations by destroying many individuals might indeed include over-hunting - or in the case of an impact, a big enough one, removing populations on a regional to continental or even global scale - whilst indirect causes are responses to environmental change leading to stress in population, perhaps due to the poor availability of grazing leading to increased vulnerability to disease or reduced reproductive rates. So in this case, as yet poorly-understood ecological changes were followed, or were then accompanied by, the Clovis hunters; a possible but disputed extraterrestrial impact 12,900 years ago may have been one of the factors leading to a significant climatic cooling yet the megafauna hung on until after the end of the Younger Dryas when conditions once again warmed up. Within a few centuries, the North American megafauna were then gone for good.

it doesn't always have to be the big one-off catastrophe events that can lead to the disappearance of faunas: just as often it is subtle pressures that build up over centuries until the system gets stressed to the point of malfunctioning and ceases to provide the life-support that is so vitally-needed. Given the pressures to which we are subjecting many planetary ecosystems, we should read the latter as a very plain warning about the future under a business-as-usual scenario."

As determined by the International Commission on Stratigraphy the Holocene began at the end of the Pleistocene (at 11,700 calendar years BP).  The Holocene is known as having had a relatively stable climate compared with other time periods; which is probably due to anthropogenic impact, thus justifying replacing the name Holocene with Anthropocene.


See also:
http://en.wikipedia.org/wiki/Younger_Dryas
Extract: "The Younger Dryas is often linked to the adoption of agriculture in the Levant. It is argued that the cold and dry Younger Dryas lowered the carrying capacity of the area and forced the sedentary Early Natufian population into a more mobile subsistence pattern. Further climatic deterioration is thought to have brought about cereal cultivation. While there exists relative consensus regarding the role of the Younger Dryas in the changing subsistence patterns during the Natufian, its connection to the beginning of agriculture at the end of the period is still being debated."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #26 on: July 05, 2015, 08:13:24 PM »
The following linked reference provides further evidence about the Sixth Mass Extinction.  Even if the Anthropocene winds-up with a different definition than coinciding with the Holocene Extinction; it is clear to me that as a minimum, such a sixth mass extinction serves as a "canary in the coal mine", acting as a warming that mankind could be included in the list of extinct species if we are not careful.
Gerardo Ceballos, Paul R. Ehrlich, Anthony D. Barnosky, Andrés García, Robert M. Pringle and Todd M. Palmer (19 Jun 2015), "Accelerated modern human–induced species losses: Entering the sixth mass extinction", Science Advances, Vol. 1, no. 5, e1400253, DOI: 10.1126/sciadv.1400253

http://advances.sciencemag.org/content/1/5/e1400253

Abstract: "The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing in the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 114 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing."

See also:
http://www.nbcnews.com/science/environment/scientists-build-case-sixth-extinction-say-it-could-kill-us-n378586
http://news.stanford.edu/news/2015/june/mass-extinction-ehrlich-061915.html
http://www.huffingtonpost.com/todd-r-miller/farewell-larsen-b_b_7581640.html
http://www.livescience.com/51280-the-new-dying-how-human-caused-extinction-affects-the-planet-infographic.html

(see also the attached image from this reference)
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #27 on: July 05, 2015, 08:15:03 PM »
The following reference by the Anthropocene Working Group released in June 2015, indicates that the Group is focusing its attention on the great acceleration of anthropogenic impacts on Earth Systems since World War II, and thus is not very light to adopt my suggestion to simply rename the Holocene as the Anthropocene:

Members of the Anthropocene Working Group: Jan Zalasiewicz, et al., (2015), "Colonization of the Americas, ‘Little Ice Age’ climate, and bomb-produced carbon: Their role in defining the Anthropocene", The Anthropocene Review August 2015 vol. 2 no. 2 117-127; doi: 10.1177/2053019615587056

http://anr.sagepub.com/content/2/2/117.abstract

Abstract: "A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tests). We discuss both of these novel suggestions, and consider that there is insufficient stratigraphic basis for the former, whereas placing the latter at the peak of the signal rather than at its inception does not follow normal stratigraphical practice. Wherever the boundary is eventually placed, it should be optimized to reflect stratigraphical evidence with the least possible ambiguity."

See also:
http://www.cbc.ca/news/technology/humans-causing-catastrophic-ecosystem-shifts-study-finds-1.3133752
Extract: "In the past, volcanic eruptions, complex ecological breakdowns or meteor strikes caused structural changes to the planet, he said.
In contrast, today's shifts — including climate change, ocean acidification, and the loss of biodiversity — have created a "new kind of nature", he said.
"Global warming as a phenomenon is just beginning," Zalasiewicz said. "Species extinctions and other changes are far more advanced."
Since 1900, extinction rates for vertebrates have been between 10 and 100 times higher than normal levels, he said. At least 468 creatures have been eliminated from the planet since then, he said, including the Costa Rican golden toad and Yangtze dolphin.
Human-caused environmental changes have accelerated rapidly since the end of World War Two, as technology has advanced and resource use intensified, Zalasiewicz said.
"When global warming really bites, that will ratchet up the changes currently taking place," he said."

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #28 on: July 05, 2015, 08:17:03 PM »
The following two linked articles highlight the fact that the imminent formal geological defining of the Anthropocene Epoch (some say Era) thrusts anthropology into the forefront of the discussion on this controversial and still poorly defined, and highly political, term:

Jason Antrosio & Sallie Han (2015), "Hello Anthropocene: Climate Change and Anthropology"; Open Anthropology, The Editors’ Note: Volume 3 Number 1

http://www.anthropology-news.org/index.php/2015/03/16/hello-anthropocene-climate-change-and-anthropology/

Extract: "Whether or not it is ever named Word of the Year (an honor the Oxford Dictionaries bestowed upon vape in 2014) or recognized officially as a geological epoch, “Anthropocene” has become a catchword for climate change today. Credited to chemist Paul Krutzen and biologist Eugene Stoermer, the term calls attention to the impact of human activity on the planet. Not only is climate change considered one of the most pressing issues of our time, but anthropology as the “study of humanity” is being pressed for answers and solutions. As Bruno Latour told the American Anthropological Association in his December 2014 keynote address, Anthropology at the Time of the Anthropocene:

Suddenly, with the question of the Anthropocene everywhere on the table, anthropologists are confronted head on with the question of urgency and political relevance. . . . To the bewilderment of many, it is all the disciplines that are now seized by the same feeling of urgency and the heated necessity of “doing something” and influencing policy on hundreds of issues for which academics are suddenly pushed to the forefront. (AAA-7)

Not only is climate change considered one of the most pressing issues of our time, but anthropology as the “study of humanity” is being pressed for answers and solutions."

As Bruno Latour told the American Anthropological Association:

Bruno Latour (Dec 2014), "Anthropology at the Time of the Anthropocene - a personal view of what is to be studied", Distinguished lecture American Association of Anthropologists, Washington December 2014

http://www.bruno-latour.fr/sites/default/files/139-AAA-Washington.pdf
Extract: "I am of course referring here to the strange undertaking by the “subcommittee of Quaternary stratigraphy” headed by my new friend, Jan Zalaciewicz, to name the geological period that might terminate the 13.000 year old Holocene, through the amazing label of Anthropocene. I know the label is still disputed. I am well aware that it is highly contentious (the dates vary wildly from 1945 to 3000 BCA; the proofs from sediments are still unsettled; the politics of it are utterly fuzzy).  And yet I really think Dipesh Chakrabarty was right to seize upon this tiny terminological innovation as something that could trigger an entirely different conversation among historians. What is true of post colonial or Marxian historians, should even be truer of anthropologists, and many sessions at this meeting make the point already. In an earlier time, any anthropologists who would have claimed that even geology was made out of human activity would have been considered, and rightly so, as megalomaniacal.

….

First, the very idea of the Anthropocene places the “human agency”
(still undifferentiated, taken en bloc and generically) smack in the center
of attention.



Everybody it seems is now converging on the same problem, ready to make the same mistakes and to live through the same traumatic experience as what the discipline of anthropology as a whole had lived through since the beginning of the 19th century: namely, how to get bones and divinities fit together.



To the great surprise of those who had tried to paint the human agent as a bag of proteins, computerized neurons and selfish calculations, it is as a moral character that human agency is entering the geostory of the Anthropocene.



The “anthropos” of the Anthropocene is not exactly any body, it is made of highly localised networks of some individual bodies whose responsibility is staggering.

This is what the definition of the Anthropocene could do: it gives another definition of time, it redescribes what it is to stand in space, and it reshuffles what it means to be entangled within animated agencies. At the time of the Anthropocene, anthropology is not a specialized discipline; it is the name of what it is to reoccupy the time and space taken out of all of us by the modernizing frontier."

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #29 on: July 05, 2015, 08:18:34 PM »
The linked Ruddiman et al 2015 reference and the following Huffington Post article provide additional insight into the complex nature of the Anthropocene:

William F. Ruddiman, Erle C. Ellis, Jed O. Kaplan & Dorian Q. Fuller (3 April 2015), "Defining the epoch we live in", Science, Vol. 348 no. 6230 pp. 38-39, DOI: 10.1126/science.aaa7297

http://www.sciencemag.org/content/348/6230/38

Abstract: "Human alterations of Earth's environments are pervasive. Visible changes include the built environment, conversion of forests and grasslands to agriculture, algal blooms, smog, and the siltation of dams and estuaries. Less obvious transformations include increases in ozone, carbon dioxide (CO2), and methane (CH4) in the atmosphere, and ocean acidification. Motivated by the pervasiveness of these alterations, Crutzen and Stoermer argued in 2000 that we live in the “Anthropocene,” a time in which humans have replaced nature as the dominant environmental force on Earth (1). Many of these wide-ranging changes first emerged during the past 200 years and accelerated rapidly in the 20th century (2). Yet, a focus on the most recent changes risks overlooking pervasive human transformations of Earth's surface for thousands of years, with profound effects on the atmosphere, climate, and biodiversity."



http://www.huffingtonpost.com/paul-stoller/welcome-to-the-anthropocene_b_6240786.html
Extract: "We live in very troubled times -- welcome to the Anthropocene, a new epoch during which human activity (industrial production and consumption) has provided us unparalleled wealth but also an unmistakable path toward potential ecological devastation. As Naomi Klein powerfully demonstrates in her new book, This Changes Everything, the structures of our political and economic systems, which are inextricably linked, are leading us toward irrevocable climate change and inconceivable social transformation.
….
The Anthropocene presents to anthropologists and other social scientists a profoundly humanitarian obligation. As the Songhay people of Niger like the say: even though the path toward truth is long, it is one that is always worth taking."

See also:
http://anthropologyreport.com/climate-change/

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #30 on: July 05, 2015, 08:20:22 PM »
Geologic epochs are normally defined by extinction events, and the following two linked references/articles emphasize that the current Sixth Mass Extinction, that started at the beginning of the Holocene Epoch, is anthropogenically dominated and almost certainly qualifies as a new Era (let alone qualifying as a new Epoch).  Nevertheless, as most scientists (including the International Anthropocene Working Group) do not deal well with political pressure, they are more than happy to punt on the definition of the Anthropocene and fixate on nuclear fallout as a marker to delineate the beginning of the Anthropocene.  Mankind's dominance of the various Earth Systems began when his technology (hunting & fires) caused the Mega Fauna Extinction to tip the Younger Dryas into an unnatural rapid end, leading to an unnaturally stable Holocene Epoch that should be re-defined as the Anthropocene Epoch (or Era as the interaction between the biosphere & the technosphere will almost certainly only accelerate in the future):

Mark Williams, Jan Zalasiewicz, PK Haff2, Christian Schwägerl, Anthony D Barnosky & Erle C Ellis (2015), "The Anthropocene biosphere", The Anthropocene Review, doi: 10.1177/2053019615591020

http://anr.sagepub.com/content/early/2015/06/17/2053019615591020.abstract

Abstract: "The geological record preserves evidence for two fundamental stages in the evolution of Earth’s biosphere, a microbial stage from ~3.5 to 0.65 Ga, and a metazoan stage evident by c. 650 Ma. We suggest that the modern biosphere differs significantly from these previous stages and shows early signs of a new, third stage of biosphere evolution characterised by: (1) global homogenisation of flora and fauna; (2) a single species (Homo sapiens) commandeering 25–40% of net primary production and also mining fossil net primary production (fossil fuels) to break through the photosynthetic energy barrier; (3) human-directed evolution of other species; and (4) increasing interaction of the biosphere with the technosphere (the global emergent system that includes humans, technological artefacts, and associated social and technological networks). These unique features of today’s biosphere may herald a new era in the planet’s history that could persist over geological timescales."


https://news.vice.com/article/the-fallout-from-old-nuclear-tests-might-help-scientists-mark-a-new-geologic-age

Extract: "Researchers are debating when we entered what they've dubbed the Anthropocene—the epoch in which mankind began to reshape the planet around us. Was it in the 1600s, when Europeans brought cattle and smallpox to the Americas and spread crops like potatoes and corn around the globe? Perhaps the late 1700s, when the steam engine ushered in the widespread burning of fossil fuels? How about post-World War II trade boom, when lightweight metals like aluminum and new substances like plastics became common worldwide?

It's more than just an academic debate. Previous epochs are usually defined by their extinctions—think of how dinosaurs gave way to the rise of mammals and birds. And recent studies show animals around us are disappearing at a rapid clip.



The most recent epoch, known as the Holocene, dates back to the end of the last ice age nearly 12,000 years ago. It's the geologic age in which humans learned to domesticate animals, grow food, build cities, and write down their thoughts, creating what's often called "civilization as we know it."

But that civilization has brought about such an extensive reordering of animal life that pound-for-pound, barely 3 percent of living vertebrates can still considered wildlife, said Waters, a member of the British Geological Survey and part of a committee of scientists tasked with defining the Anthropocene.

"Domesticated animals and pets — those species that mankind has favored — in effect represent 97 percent of the weight of vertebrate animals on the planet," he told VICE News. Chickens and cows, dogs and cats, and the crops raised to feed them "spread across all the continents and become the dominant biota," he said.

Meanwhile, Waters said, about one species a year has gone extinct over most of the past few hundred years — but that rate has gone up sharply in the past century. In a study released in late June, US and Mexican scientists warned that a new mass extinction could be at hand, with more than vertebrate species disappearing since 1900.

In a response published this week, the committee on which Waters sits poured cold water on the earlier date. Human activity had nothing to do with the dip in carbon dioxied, it concluded, and its effects don't show up as a clear point in the geologic record. It was more sympathetic to the idea of using radioactive materials, though it suggested a different year and isotope.

Lewis said that the arbiters of the Anthropocene should publish some guidelines for determining which event would be most definitive and let scientists sort it out."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Rubikscube

  • Frazil ice
  • Posts: 254
    • View Profile
  • Liked: 5
  • Likes Given: 4
Re: Early Anthropocene
« Reply #31 on: July 06, 2015, 01:49:36 AM »
Thanks a lot ASLR, fabulous posts.

I sometimes wonder if there is any point in trying to put a date on the Anthropocene, not because I'm a nihilist, but because it seems pretty ridiculous trying to pin the transition down to an exact year or date when this is all part of the same ongoing transition without a know result. Moreover, it currently looks like humans are substituting the asteroids and volcanoes usually responsible for the transition between two eras rather than shaping an era of our own which we are entitled to name after ourselves. Maybe Anthropocene is just a transition period that we can neither call an epoch nor an era before the Earth Systems are stabilized and the ongoing mass extinction has ended?

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #32 on: July 06, 2015, 02:14:09 AM »
Rubikscube,

While I cheer-on the US women's team in the World Cup final against a tough team-Japan, I will pause to note that:

- I agree that for different purposes/objectives, the Anthropocene (Epoch/Era?) could be defined in any of a variety of ways and could be defined to start at any one of a variety of dates.  In this sense the Anthropocene is going to do what it does, no matter how we define it.

- Nevertheless, while definitions may not mean anything to nature, they do seem to mean something to humans.  We frequently use definitions to absolve ourselves of responsibility; while if mankind if ever again going to stop being the dominate positive forcing factor for climate change; then I believe that it would be advisable for us to acknowledge we started effecting the climate state  somewhere near the beginning of the current Holocene Epoch.

Best ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

sidd

  • First-year ice
  • Posts: 6774
    • View Profile
  • Liked: 1047
  • Likes Given: 0
Re: Early Anthropocene
« Reply #33 on: July 06, 2015, 08:01:34 PM »
Welcome back.

Thanks for the pointer to the Latour piece. As usual it is worth reading, although i do not agree with him in many areas. I see connections with the recent encyclical also, but a detailed cross reading will have to wait.

sidd

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #34 on: July 06, 2015, 08:15:24 PM »
sidd,

Thanks for the welcome back.  I concur that the Encyclical is relevant to discussion about the Anthropocene (see the "Adapting to the Anthropocene" thread).

Best,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #35 on: July 13, 2015, 06:05:43 PM »
The linked Wikipedia article discusses the early Anthropocene theory presented by William Ruddiman, that the beginning of intense agriculture about 8,000 years ago initiated the Anthropocene.  Such proposed theories highlight the fact that for different purposes different definitions of the Anthropocene have more merit.  Nevertheless, I still favor replacing the entire Holocene Epoch with an Anthropocene Era:

https://en.wikipedia.org/wiki/Early_anthropocene

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #36 on: July 13, 2015, 06:16:41 PM »
For those who want to monitor the most current thinking (see the extract below on the definition of the Anthropocene) of the WORKING GROUP ON THE 'ANTHROPOCENE' you can periodically check the link below:

http://quaternary.stratigraphy.org/workinggroups/anthropocene/

Extract: "What is the 'Anthropocene'? - current definition and status
The 'Anthropocene' is a term widely used since its coining by Paul Crutzen and Eugene Stoermer in 2000 to denote the present time interval, in which many geologically significant conditions and processes are profoundly altered by human activities. These include changes in: erosion and sediment transport associated with a variety of anthropogenic processes, including colonisation, agriculture, urbanisation and global warming. the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements such as carbon, nitrogen, phosphorus and various metals. environmental conditions generated by these perturbations; these include global warming, ocean acidification and spreading oceanic 'dead zones'. the biosphere both on land and in the sea, as a result of habitat loss, predation, species invasions and the physical and chemical changes noted above.
The 'Anthropocene' is not a formally defined geological unit within the Geological Time Scale. A proposal to formalise the 'Anthropocene' is being developed by the 'Anthropocene' Working Group for consideration by the International Commission on Stratigraphy, with a current target date of 2016. Care should be taken to distinguish the concept of an 'Anthropocene' from the previously used term Anthropogene (cf. below**).
The 'Anthropocene' is currently being considered by the Working Group as a potential geological epoch, i.e. at the same hierarchical level as the Pleistocene and Holocene epochs, with the implication that it is within the Quaternary Period, but that the Holocene has terminated. It might, alternatively, also be considered at a lower (Age) hierarchical level; that would imply it is a subdivision of the ongoing Holocene Epoch.
Broadly, to be accepted as a formal term the 'Anthropocene' needs to be (a) scientifically justified (i.e. the 'geological signal' currently being produced in strata now forming must be sufficiently large, clear and distinctive) and (b) useful as a formal term to the scientific community. In terms of (b), the currently informal term 'Anthropocene' has already proven to be very useful to the global change research community and thus will continue to be used, but it remains to be determined whether formalisation within the Geological Time Scale would make it more useful or broaden its usefulness to other scientific communities, such as the geological community.
The beginning of the 'Anthropocene' is most generally considered to be at c. 1800 CE, around the beginning of the Industrial Revolution in Europe (Crutzen's original suggestion); other potential candidates for time boundaries have been suggested, at both earlier dates (within or even before the Holocene) or later (e.g. at the start of the nuclear age). A formal 'Anthropocene' might be defined either with reference to a particular point within a stratal section, that is, a Global Stratigraphic Section and Point (GSSP), colloquially known as a 'golden spike; or, by a designated time boundary (a Global Standard Stratigraphic Age)."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #37 on: July 18, 2015, 06:54:22 PM »
In my earlier posts, I more or less took it as a given that homo sapiens sapiens were the driving forces behind the megafauna extinctions; however, the following linked reference (with an open access pdf) provides solid evidence that humans were the dominant force behind the megafauna extinctions as opposed to changes in the climate.  Furthermore, this reference (see the attached map & caption) points out the complexity that archaic hominin preconditioned megafauna in Africa and Southern Asia so that on a percentage basis the megafauna extinctions were lower in these areas than in Australia, Europe and the New World.  In my opinion this evidence and sequence supports the idea that homo sapiens sapiens contributed to the triggering of the Holocene, thus justifying re-naming the Holocene Epoch as the Anthropocene Era:

Christopher Sandom, Søren Faurby, Brody Sandel, Jens-Christian Svenning (4 June 2014), "Global late Quaternary megafauna extinctions linked to humans, not climate change", Proceedings of The Royal Society B, Vol 281, No. 1787, DOI: 10.1098/rspb.2013.3254


http://rspb.royalsocietypublishing.org/content/281/1787/20133254
http://rspb.royalsocietypublishing.org/content/royprsb/281/1787/20133254.full.pdf

Abstract: "The late Quaternary megafauna extinction was a severe global-scale event. Two factors, climate change and modern humans, have received broad support as the primary drivers, but their absolute and relative importance remains controversial. To date, focus has been on the extinction chronology of individual or small groups of species, specific geographical regions or macroscale studies at very coarse geographical and taxonomic resolution, limiting the possibility of adequately testing the proposed hypotheses. We present, to our knowledge, the first global analysis of this extinction based on comprehensive country-level data on the geographical distribution of all large mammal species (more than or equal to 10 kg) that have gone globally or continentally extinct between the beginning of the Last Interglacial at 132 000 years BP and the late Holocene 1000 years BP, testing the relative roles played by glacial–interglacial climate change and humans. We show that the severity of extinction is strongly tied to hominin palaeobiogeography, with at most a weak, Eurasia-specific link to climate change. This first species-level macroscale analysis at relatively high geographical resolution provides strong support for modern humans as the primary driver of the worldwide megafauna losses during the late Quaternary."

Caption for image: "Global maps of late Quaternary large mammal extinction severity, hominin palaeobiogeography, temperature anomaly and precipitation velocity. (a) The proportion of extinct large mammal species (more than or equal to 10 kg) in each TDWG country during the last 132 000 years, only counting extinctions earlier than 1000 years BP. (b) The cumulative number of extinct large mammal species occurring in each TDWG country. (c) Hominin palaeobiogeography (see the text for further explanation). (d) Mean anomaly in mean annual temperature between the LGM and today. (e) Mean velocity in annual precipitation between the LGM and today. TDWG countries shaded in dark grey were excluded from analyses. The climate change variables were standardized to range between 0 and 1."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #38 on: July 24, 2015, 04:19:40 PM »
The linked reference provides a holistic examination (particularly including new DNA findings) showing that abrupt warming events prior to the Pleistocene/Holocene boundary reveals the importance of climate change (particularly during warming phases like now) on megafauna extinction; but as indicated by the following concluding sentence, this climate stress left the megafauna susceptible to human impact (particularly during the warm periods when migrating people had more access), who may have pulled the trigger for the megafauna extinction: "The presence of many cryptic biotic transitions prior to the Pleistocene/Holocene boundary revealed by ancient DNA confirms the importance of climate change in megafaunal population extinctions and suggests that metapopulation structures necessary to survive such repeated and rapid climatic shifts were susceptible to human impacts."


Alan Cooper, Chris Turney, Konrad A. Hughen, Barry W. Brook, H. Gregory McDonald & Corey J. A. Bradshaw (July 23 2015), "Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover", Science DOI: 10.1126/science.aac4315


http://www.sciencemag.org/content/early/2015/07/22/science.aac4315


Abstract: "The mechanisms of Late Pleistocene megafauna extinctions remain fiercely contested, with human impact or climate change cited as principal drivers. Here, we compare ancient DNA and radiocarbon data from 31 detailed time series of regional megafaunal extinctions/replacements over the past 56,000 years with standard and new combined records of Northern Hemisphere climate in the Late Pleistocene. Unexpectedly, rapid climate changes associated with interstadial warming events are strongly associated with the regional replacement/extinction of major genetic clades or species of megafauna. The presence of many cryptic biotic transitions prior to the Pleistocene/Holocene boundary revealed by ancient DNA confirms the importance of climate change in megafaunal population extinctions and suggests that metapopulation structures necessary to survive such repeated and rapid climatic shifts were susceptible to human impacts."


Also see:
http://www.washingtonpost.com/news/energy-environment/wp/2015/07/23/humans-may-be-off-the-hook-for-mammoth-extinctions-say-scientists/

Extract: "Cooper’s model suggests that climate-driven extinction events happened in a pattern over time, closely tied to warming events that occurred through the era, going back until at least 50,000 years ago. Those patterns, Cooper said, weren’t always discernible from the fossil record. Instead, the team used a combination of DNA and radiocarbon dating to link localized megafauna extinctions to a series of rapid warming events over time.
The research team’s next step is to try and establish which aspect of the warming periods is the driving force behind the extinctions. “We can see the relationship between the warming periods and the extinctions,” Cooper said, “but can’t tell whether its the warming or the pace of change. It’s one of the two.”
Although there’s still more work to do, Cooper hopes his findings might help to illustrate the importance of considering our own climate today. “If we’re right, and these warming events are the key problem,” he said, “it’s quite obvious that the current global warming trends are very worrying, because they in many ways represent the conditions of the start of an interstadial.”"
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #39 on: August 05, 2015, 06:39:01 PM »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

TerryM

  • First-year ice
  • Posts: 6002
    • View Profile
  • Liked: 893
  • Likes Given: 5
Re: Early Anthropocene
« Reply #40 on: August 05, 2015, 09:05:17 PM »
The Black Mat


Something happened ~ 12,900 BP in North America that caused the collapse of a huge number of species. One of the attempts to explain this die off is the Black Mat theory proposed by Firestone (& Goodyear, believe it or not).


The die-off was massive including everything from mammoths and mastodons, a number of horse and camel species, dire wolves, saber toothed cats and giant beaver. For years man was thought to be responsible for this extinction, but, when one recalls the unsuccessful extermination of modern wolves by hunters in helicopters, the difficulty of capturing, let alone killing wild horses and the resistance that a sabertoothed lion would present to anyone armed only with a thrusting spear, the problems multiply.


Rapid climate change certainly occurred at this time, but these were animals that had made it through the ice age & it's difficult to imagine the following warm period to have been responsible. Besides which we'd expect at least some to have escaped to higher elevations.


http://archaeology.about.com/b/2008/04/28/clovis-black-mats-and-extra-terrestrials.htm


The above is an overview by an archaeologist who if I recall properly eventually rejected the theory.


At Murray Springs, and at least 70 other Clovis sites in N. America a dark strata is found just above the layer containing Clovis and megafaunal remains. The dark material has a magnetic component, contains iridium, microspherules, nanodiamonds and fullerenes. These materials are found in other locations, but are found in greater concentrations within the black mat. Iridium is of course the extra-terrestrial material that proved the dinosaur era ended with a bang.


Firestone et. al. propose that a large comet struck the Laurentide ice sheet somewhere north of the Great Lakes, exploded in the atmosphere, and the resulting fireball(s) ignited America's forests and killed almost everything living above ground.


The theory has not been accepted as of yet, but this is not unexpected. It took generations before plate tectonics, abiotic oil and dinosaur killing asteroids to gain acceptance . It may be that some other explanation will be proven true, but until then the Black Mat Theory deserves our attention.


Terry

Donna

  • New ice
  • Posts: 22
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: Early Anthropocene
« Reply #41 on: August 05, 2015, 09:44:57 PM »
The Black Mat


Something happened ~ 12,900 BP in North America that caused the collapse of a huge number of species. One of the attempts to explain this die off is the Black Mat theory proposed by Firestone (& Goodyear, believe it or not).


The die-off was massive including everything from mammoths and mastodons, a number of horse and camel species, dire wolves, saber toothed cats and giant beaver. For years man was thought to be responsible for this extinction, but, when one recalls the unsuccessful extermination of modern wolves by hunters in helicopters, the difficulty of capturing, let alone killing wild horses and the resistance that a sabertoothed lion would present to anyone armed only with a thrusting spear, the problems multiply.




Terry

Terry - fascinating theory!  Thanks so much for the info and the link.

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #42 on: September 03, 2015, 10:11:13 PM »
The linked Yale article makes it very clear that man has been impacting the climate thru deforestation since the beginning of the Holocene:

http://news.yale.edu/2015/09/02/seeing-forest-and-trees-all-3-trillion-them

Extract: "But the total number of trees has plummeted by roughly 46% since the start of human civilization, the study estimates.



“We’ve nearly halved the number of trees on the planet, and we’ve seen the impacts on climate and human health as a result,” Crowther said. “This study highlights how much more effort is needed if we are to restore healthy forests worldwide.”"
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #43 on: September 26, 2015, 06:17:08 PM »
It is interesting to think that climate change made man what he is, and now man makes climate change that will make man what he is yet to become:

https://www.newscientist.com/article/mg22730394-100-key-moments-in-human-evolution-were-shaped-by-changing-climate/


Extract: "A climate that shifts from wet to dry every 10 or 20,000 years would have selected for humans that had a capacity to adjust to change, whatever it may be. For example, big brains would have allowed us to solve problems caused by changes in rainfall, such as by making different stone tools to exploit changing food resources.
In 1996, Potts published the idea in a book, calling it “variability selection”. But it was just that: an idea. The trick was finding hard evidence.
Now, a series of papers by Potts and others finds evidence suggesting he is right. “They show quite convincingly, I think, that the evolution of humans into large-brained, bipedal animals… has come about through a close and adaptive relationship with changing climate,” says Varsha Pilbrow from the University of Melbourne in Australia, who wasn’t involved in the work."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #44 on: October 18, 2015, 12:19:11 AM »
The linked article indicates evidence supporting an increased probability that humans were responsible for the extinction of mammoths (which supports my general position in this thread that the entire Holocene could reasonably be renamed the Anthropocene):

http://www.lighthousenewsdaily.com/woolly-mammoths/2364/

Extract: "Mammoth tusks have a story to tell and its end is not pretty: woolly mammoths are gone and we are to blame. A recent study points the finger at reckless hunting rather than global warming in woolly mammoth extinction.

Past studies had shown that woolly mammoths went extinct because of natural global warming at the end of the last glacial period, reckless hunting or both. But although there are dozens of studies on the issue, the problem has yet to be resolved.

But a team of researchers from the University of Michigan argue that chemical hints in baby mammoth tusks may hold the key to the issue. Scientists reported that an isotopic signature in tusks revealed that the weaning age in mammoth populations steadily decreased by about three years before the ice-age pachyderms went extinct.

Weaning age marks the time when a baby animal stops nursing. While changes brought by global warming in animals’ nutrition delay weaning ages including those in modern day elephants, predatory pressure forces animals to reach adulthood faster and decrease weaning age.

Michael Cherney, one of the co-authors of the study, argued that earlier weaning is a clear sign that mammoth extinction was not caused by climate change, but by increased pressure from human hunters. Other ice-age mammals might have shared a similar fate, but more research needs to be done, researchers added.

Nevertheless, study authors acknowledged that their findings were not a final answer to explain mammoth demise. But they hope that the new theory may put the issue in a different perspective and help scientists find new approaches to unlock the mystery."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #45 on: October 19, 2015, 10:46:38 PM »
The linked article indicates that humans likely primarily responsible for the massive species extinctions at the Pleistocene Holocene transition.  Thus further supporting my position that the entire Holocene could reasonably be re-named the Anthropocene:

http://www.latimes.com/science/sciencenow/la-sci-sn-ice-age-fossils-bahama-island-extinction-climate-change-20151019-story.html

Extract: "Some have argued that dramatic climate changes occurring around the same time, a period known as the Pleistocene Holocene transition, were to blame. Others said the incursion of humans, with their hunting practices and their propensity to dramatically alter habitats, were the driving force in these species’ disappearance.


Now, by examining an underwater fossil site discovered in the Bahamas, researchers have been able to distinguish between these two forces — and found that human encroachment appears to have been more devastating than even severe climate change, according to a new study in the Proceedings of the National Academy of Sciences.

The new fossils “gave us an unparalleled snapshot at what the Ice Age life would have been like on a Caribbean isle,” said lead author David Steadman, curator of ornithology at the Florida Museum of Natural History."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Pmt111500

  • Guest
Re: Early Anthropocene
« Reply #46 on: October 20, 2015, 05:39:08 AM »
Hansen comments on Ruddimans comment (http://www.atmos-chem-phys-discuss.net/15/C5549/2015/acpd-15-C5549-2015.pdf) :

concerning the estimates of the early contributions of humans to the CO2 budget of earth:
http://www.atmos-chem-phys-discuss.net/15/C7931/2015/acpd-15-C7931-2015.pdf

setting the beginning of human influence on climate ~7500 ybp. Regardless of if the controversies regarding the Hansen & al. "ice discharge doubling time paper" discussed in the +3m thread in consequences section, he seems to cautiously endorse the Early Anthropocene hypothesis.

AbruptSLR

  • Multi-year ice
  • Posts: 19703
    • View Profile
  • Liked: 2268
  • Likes Given: 286
Re: Early Anthropocene
« Reply #47 on: January 08, 2016, 12:04:03 AM »
The linked reference is authored by a subcommittee (called the: "Anthropocene Working Group) organized under the Subcommission on Quaternary Stratigraphy.  If, over the coming months/years, the whole organization votes to approve the subcommittee's recommendations then the Anthropocene could be officially recognized as having started sometime circa 1945-1964.

Colin N. Waters, Jan Zalasiewicz, Colin Summerhayes, Anthony D. Barnosky, Clément Poirier, Agnieszka Gałuszka, Alejandro Cearreta, Matt Edgeworth, Erle C. Ellis, Michael Ellis, Catherine Jeandel, Reinhold Leinfelder, J. R. McNeill, Daniel deB. Richter, Will Steffen, James Syvitski, Davor Vidas, Michael Wagreich, Mark Williams, An Zhisheng, Jacques Grinevald, Eric Odada, Naomi Oreskes & Alexander P. Wolfe (8 January 2016), "The Anthropocene is functionally and stratigraphically distinct from the Holocene", Science, Vol. 351, no. 6269, DOI: 10.1126/science.aad2622

http://www.sciencemag.org/content/351/6269/aad2622

Abstract: "Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sediments, including aluminum, plastics, and concrete, coincides with global spikes in fallout radionuclides and particulates from fossil fuel combustion. Carbon, nitrogen, and phosphorus cycles have been substantially modified over the past century. Rates of sea-level rise and the extent of human perturbation of the climate system exceed Late Holocene changes. Biotic changes include species invasions worldwide and accelerating rates of extinction. These combined signals render the Anthropocene stratigraphically distinct from the Holocene and earlier epochs."

See also:
https://www.washingtonpost.com/news/energy-environment/wp/2016/01/07/scientists-say-humans-have-now-brought-on-an-entirely-new-geologic-epoch/

Extract: "A group of 24 geoscientists on Thursday released a bracing assessment, suggesting that humans have altered the Earth so extensively that the consequences will be detectable in current and future geological records. They therefore suggest that we should consider the Earth to have moved into a new geologic epoch, the “Anthropocene,” sometime circa 1945-1964.
The current era (at least under present definitions), known as the Holocene, began about 11,700 years ago, and was marked by warming and large sea level rise coming out of a major cool period, the Younger Dryas. However, the researchers suggest, changes ranging from growing levels of carbon dioxide in the atmosphere to infusions of plastics into marine sediments suggest that we’ve now left the Holocene decisively behind — and that the proof is already being laid down in polar ice cores, deep ocean sediments, and future rocks themselves.



The concept of the “Anthropocene” was originally suggested by Paul Crutzen, a Nobel Prize winning atmospheric chemist who is also part of the “Anthropocene Working Group,” in the year 2000. The term has always denoted a new era or epoch uniquely defined by humans’ large scale impact on the environment — but the precise time of its beginning has been variously defined.
After all, humans started deforesting vast landscapes, and causing species extinctions, thousands of years ago. The industrial revolution, meanwhile, began around 200 years ago and represented a major step in how we influence the environment and consume Earth’s materials — as well as the kickstart to global warming.
However, the new study homes in on the middle of the last century as the likely marker for when the geologic “Anthropocene” truly began. The authors suggest that around this time, a confluence of major trends — population explosion, new technological advances, and booming rates of consumption — triggered changes that will be unmistakable in geologic records."

PS: Personally, I prefer an early start to the Anthropocene, but I would be happy to see it recognized officially starting at any reasonable date including the 1945-1964 timeframe.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

TerryM

  • First-year ice
  • Posts: 6002
    • View Profile
  • Liked: 893
  • Likes Given: 5
Re: Early Anthropocene
« Reply #48 on: January 08, 2016, 07:52:06 PM »
ASLR
1950 might be an advantageous time to start a the Anthropocene era as 1950 is the year assigned to BP, as in Before Present Era.
Terry

JMP

  • Frazil ice
  • Posts: 114
    • View Profile
  • Liked: 19
  • Likes Given: 62
Re: Early Anthropocene
« Reply #49 on: January 09, 2016, 02:46:27 AM »
It seems to me the discovery of petroleum and the exploitation of its highly concentrated form of energy and the sudden readily usable power-in-a-bucket is what pinpoints the sea-change.  So, yeah I'd think it should start it a hundred years earlier - 1850 - but perhaps that breaks with some other convention or something?