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AGW in general => Science => Topic started by: Pmt111500 on May 07, 2014, 09:23:06 AM

Title: Early Anthropocene
Post by: Pmt111500 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 (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 (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

Title: Re: Early Anthropocene
Post by: Gray-Wolf 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?
Title: Re: Early Anthropocene
Post by: jai mitchell 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/ (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.
Title: Re: Early Anthropocene
Post by: AbruptSLR 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.
Title: Re: Early Anthropocene
Post by: Pmt111500 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.
Title: Re: Early Anthropocene
Post by: Shared Humanity 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.
Title: Re: Early Anthropocene
Post by: icefest 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.

(https://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/World_population_growth_%28lin-log_scale%29.png/800px-World_population_growth_%28lin-log_scale%29.png)
Title: Re: Early Anthropocene
Post by: wili 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.
Title: Re: Early Anthropocene
Post by: crandles 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?
Title: Re: Early Anthropocene
Post by: jai mitchell 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:



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 (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.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fsciencetrio.files.wordpress.com%2F2010%2F02%2Fextinctionandpopulation_1026091.jpg&hash=33f4a7c5f717b035433e6f9a067179ae)

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.
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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
Title: Re: Early Anthropocene
Post by: Rubikscube 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;
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/Geochronology)
http://en.wikipedia.org/wiki/Holocene (http://en.wikipedia.org/wiki/Holocene)
http://www.geosociety.org/science/timescale/ (http://www.geosociety.org/science/timescale/)
Title: Re: Early Anthropocene
Post by: Shared Humanity 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?   :-\
Title: Re: Early Anthropocene
Post by: ccgwebmaster 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.
Title: Re: Early Anthropocene
Post by: Rubikscube 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
Title: Re: Early Anthropocene
Post by: Laurent on August 13, 2014, 10:00:54 PM
New Study Sees Atlantic Warming Behind a Host of Recent Climate Shifts
http://dotearth.blogs.nytimes.com/2014/08/03/new-study-sees-atlantic-warming-behind-a-host-of-recent-climate-shifts/?partner=rss&emc=rss (http://dotearth.blogs.nytimes.com/2014/08/03/new-study-sees-atlantic-warming-behind-a-host-of-recent-climate-shifts/?partner=rss&emc=rss)
Title: Re: Early Anthropocene
Post by: Laurent on October 17, 2014, 09:47:41 AM
Does the Anthropocene, the Age of Humans, Deserve a Golden Spike?
http://dotearth.blogs.nytimes.com/2014/10/16/does-the-anthropocene-the-age-of-humans-deserve-a-golden-spike/?partner=rss&emc=rss (http://dotearth.blogs.nytimes.com/2014/10/16/does-the-anthropocene-the-age-of-humans-deserve-a-golden-spike/?partner=rss&emc=rss)
Title: Re: Early Anthropocene
Post by: Laurent on October 17, 2014, 01:35:30 PM
Never Mind the Anthropocene – Beware the ‘Manthropocene’
http://dotearth.blogs.nytimes.com/2014/10/17/never-mind-the-anthropocene-beware-the-manthropocene/?partner=rss&emc=rss (http://dotearth.blogs.nytimes.com/2014/10/17/never-mind-the-anthropocene-beware-the-manthropocene/?partner=rss&emc=rss)
Title: Re: Early Anthropocene
Post by: Pmt111500 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 (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 (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)
Title: Re: Early Anthropocene
Post by: AbruptSLR 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/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 (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."
Title: Re: Early Anthropocene
Post by: Anne 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 (http://www.scientificamerican.com/article/mass-deaths-in-americas-start-new-co2-epoch/) as I couldn't cut and paste from the Nature article (http://www.nature.com/articles/nature14258.epdf?referrer_access_token=_PLYMXO_7pZvnC9psaNnzdRgN0jAjWel9jnR3ZoTv0NY9hwYLWp7R0oJ40dNLmwRNIWFwvx03EKJH0zM6Mp4JjECKgKbSWeNKNLccYnwNeuxIjogv-rur0GFEzyxrx_FxFErrX7NOKDqp3C93-HB8Um8CT1IsrZ6isM6iYlcM9Kp8E17tWxJ0XzRw-RhTyAn2F80gWU5U-JsIcZGtm014g%3D%3D&tracking_referrer=www.newyorker.com) though it is free to view.)
Title: Re: Early Anthropocene
Post by: AbruptSLR 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://quaternary.stratigraphy.org/workinggroups/anthropocene/)
http://www.newsweek.com/did-anthropocene-begin-deaths-50-million-native-americans-313319 (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.vox.com/2015/4/2/8335915/anthropocene-debate)
http://www.scientificamerican.com/article/did-the-anthropocene-begin-in-1950-or-50-000-years-ago/ (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/abstract;jsessionid=4642F856F01B3EE7C526138127CEE75F.f01t01)
http://onlinelibrary.wiley.com/doi/10.1002/jqs.1227/epdf (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://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 (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) (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 (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 (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://en.wikipedia.org/wiki/Human)
http://www.thefreedictionary.com/Homo+sapiens+sapiens (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.
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (http://www.nature.com/nature/journal/v519/n7542/full/nature14258.html)
https://eorder.sheridan.com/3_0/app/orders/4609/article.php#171 (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 (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 (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 (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 (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."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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 (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 (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 (http://www.sci-news.com/othersciences/anthropology/science-anthropocene-new-geological-epoch-02405.html)

Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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.)"
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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 (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."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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://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://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.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 (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)
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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 (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."

Title: Re: Early Anthropocene
Post by: AbruptSLR 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/ (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 (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."

Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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 (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/ (http://anthropologyreport.com/climate-change/)

Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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 (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."
Title: Re: Early Anthropocene
Post by: Rubikscube 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?
Title: Re: Early Anthropocene
Post by: AbruptSLR 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
Title: Re: Early Anthropocene
Post by: sidd 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
Title: Re: Early Anthropocene
Post by: AbruptSLR 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
Title: Re: Early Anthropocene
Post by: AbruptSLR 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

Title: Re: Early Anthropocene
Post by: AbruptSLR 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/ (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)."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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/281/1787/20133254)
http://rspb.royalsocietypublishing.org/content/royprsb/281/1787/20133254.full.pdf (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."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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/ (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.”"
Title: Re: Early Anthropocene
Post by: AbruptSLR on August 05, 2015, 06:39:01 PM
A-Team provided these links, from July 23 2015, in another thread


http://phys.org/news/2015-07-mammoths-abrupt-climate.html (http://phys.org/news/2015-07-mammoths-abrupt-climate.html)
http://www.sciencemag.org/content/early/2015/07/22/science.aac4315 (http://www.sciencemag.org/content/early/2015/07/22/science.aac4315)
Title: Re: Early Anthropocene
Post by: TerryM 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 (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
Title: Re: Early Anthropocene
Post by: Donna 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.
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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.”"
Title: Re: Early Anthropocene
Post by: AbruptSLR 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/ (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."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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/ (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."
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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."
Title: Re: Early Anthropocene
Post by: Pmt111500 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 (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 (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.
Title: Re: Early Anthropocene
Post by: AbruptSLR 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 (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/ (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.
Title: Re: Early Anthropocene
Post by: TerryM 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
Title: Re: Early Anthropocene
Post by: JMP 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?     
Title: Re: Early Anthropocene
Post by: AbruptSLR on January 09, 2016, 03:15:20 AM
Terry & JMP,

Apparently, as this will define a new geologic time unit, there needs to be "golden spike" that can be dug-up from the Earth (like fallout radionuclides or particulates from fossil fuel combustion) rendering the Anthropocene stratigraphically distinct from the Holocene and earlier epochs.  I imagine that before the full geologic society votes to create the Anthropocene one of the many possible stratigrahic layers deposited between 1945 & 1964 will be selected and the year in which that layer was deposited will be the starting point for the Anthropocene.

Best,
ASLR
Title: Re: Early Anthropocene
Post by: Juan C. García on January 09, 2016, 05:49:28 AM
From my point of view, the Anthropocene should start when humanity generate a great event on the planet. Even that atomic bombs, per example, where an important event, they did not have a great effect on Earth. We can talk about the ozone hole, that is a great influence of humanity on our planet, but I believe that the greatest effect that humanity is going to make on our planet, that could change our lifestyle on very different ways, is the melt of the Arctic Sea Ice. This event can (and I believe it will) be the starting point to the melt of Greenland, to change the coastlines of the continents, it will accelerate global warming in different ways, etc.
So, from my point of view, 2007 should be considered the starting point to the Anthropocene.
I recommended you to see the following presentation of Mark Serreze on the 2007 AGU Fall Meeting and considered how he finds 2007 as a possible “point of no return” or “tipping point”, at the same time that he forecast 2030 as a year with a possible Arctic ice-free on summer. He also affirms that the Arctic sea ice will disappear abruptly, ¿so why a linear trend on all the NSIDC monthly graphs? After having 2007, 2011 and 2015 with almost the same level of ASI, and after 2012 with remarkably lower ice, shouldn´t we considerer 2007 as the year that mark the point of no return?

http://www.agu.org/webcast/fm07/Serreze/index.html (http://www.agu.org/webcast/fm07/Serreze/index.html)
Title: Re: Early Anthropocene
Post by: ael on January 09, 2016, 07:27:35 AM
With so much fossil fuel having been burned, it has made carbon 14 aging useless for "modern" artifacts.   That is almost a golden spike.
Title: Re: Early Anthropocene
Post by: LRC1962 on January 09, 2016, 11:08:03 AM
Each specially named period of time has a name because there is a defining layer in the fossil record that can be found. This layer is either defined by a mass extinction event or a mass diversification in the plants and animals. The exact period is also farther defined because the understanding of what was happening climatologically.
IMHO the Holocene period should have its own distinct period because climatologically it was unusually very stable and allowed humans to become the dominate species in the world. As far as this latest time period I believe it should have its start at the beginning of the Industrial revolution. Why?
There will be a very distinct layer in the fossil record because it was a start of global geoengineering in that valleys were filled in and mountains flattened. Also you had the development of massive garbage disposal on a global scale which includes dispersal of very human engineered chemicals.
The final nail will be the very obvious signature of the start of exponential growth of FF CO2. The result of that would the the very rapid rise in global temperatures, which combined the with the geoengineering efforts and industrialization of food production results in the mass extinction of a large percentage of the living organisms.
There will be obvious geoengineering efforts to 'fix' the problem, but results of that will be as yet to be determined because we have no idea what path will be attempted and how successful it will be. In any case it would still be part of the new named period of time because it would be humans trying to still be the dominate force over what is happening over nature.
Granted how geologists will end up determining what type of time period it will be, it will still be a unique time period because it will have its own unique features that 'broke' the 'normal' flow of geological events.
Arguments can be made for the start of agriculture, start of city dwelling, start of large empires, but in each of those cases global impact was still minimal because nature could still reclaim what man had done. The Industrial Revolution changed all that because the scale of what was being done was global and what has been and is still being done to the climate is global and permanently is changing nature on a global scale, ie we can not return nature and climate to what it was like in the 1700's. Large, thick ASI will not return until CO2 and temperatures return to pre-industrial levels.
Title: Re: Early Anthropocene
Post by: AbruptSLR on January 17, 2016, 05:24:06 PM
The linked reference supports the case that early anthropogenic agricultural activity sustained the Holocene for a longer period than would naturally occur; which supports the argument for an early date for the beginning of the Anthropocene:

A.Ganopolski, R.Winkelmann and H. J.Schellnhuber (2016), "Critical insolation–CO2 relation for diagnosing past and future glacial inception", Nature, doi:10.1038/nature16494

http://www.nature.com/nature/journal/v529/n7585/full/nature16494.html (http://www.nature.com/nature/journal/v529/n7585/full/nature16494.html)

Abstract: "The past rapid growth of Northern Hemisphere continental ice sheets, which terminated warm and stable climate periods, is generally attributed to reduced summer insolation in boreal latitudes. Yet such summer insolation is near to its minimum at present, and there are no signs of a new ice age. This challenges our understanding of the mechanisms driving glacial cycles and our ability to predict the next glacial inception. Here we propose a critical functional relationship between boreal summer insolation and global carbon dioxide (CO2) concentration, which explains the beginning of the past eight glacial cycles and might anticipate future periods of glacial inception. Using an ensemble of simulations generated by an Earth system model of intermediate complexity constrained by palaeoclimatic data, we suggest that glacial inception was narrowly missed before the beginning of the Industrial Revolution. The missed inception can be accounted for by the combined effect of relatively high late-Holocene CO2 concentrations and the low orbital eccentricity of the Earth. Additionally, our analysis suggests that even in the absence of human perturbations no substantial build-up of ice sheets would occur within the next several thousand years and that the current interglacial would probably last for another 50,000 years. However, moderate anthropogenic cumulative CO2 emissions of 1,000 to 1,500 gigatonnes of carbon will postpone the next glacial inception by at least 100,000 years. Our simulations demonstrate that under natural conditions alone the Earth system would be expected to remain in the present delicately balanced interglacial climate state, steering clear of both large-scale glaciation of the Northern Hemisphere and its complete deglaciation, for an unusually long time."


Caption for first image: "Best-fit logarithmic relation (black line) between the maximum summer insolation at 65° N and the CO₂ threshold for glacial inception; grey shaded area indicates ±1s.d. Blue dots correspond to the coldest model version and red dots to the warmest."

Caption for second image: "The timing of past and future glacial inceptions can be explained by the CO2 concentration and the insolation–CO2 relation. The thin grey line depicts the CO2 threshold value for glacial inception, derived as a function of the maximum summer insolation at 65° N. The CO2 concentration from ice core data for the past 800,000 years is shown (blue line), along with the CO2 scenarios of 0 Gt C cumulative anthropogenic emissions (blue line), 500Gt C (orange line), 1,000Gt C (red line) and 1,500Gt C (dark red line). Pale blue vertical bars indicate the time periods when the reconstructed value is below the critical CO2 concentration, and the light blue bar shows the timing of a possible next glacial inception. The horizontal dotted line indicates the present-day CO2 level. The lower curve depicts a proxy for the global ice volume (thick grey line)."
Title: Re: Early Anthropocene
Post by: AbruptSLR on February 06, 2016, 08:46:24 PM
The linked, open access, reference discusses the nature of the Anthropocene and how different it is from most other known biospheric relationships:

Mark Williams, Jan Zalasiewicz, Colin N. Waters, Matt Edgeworth, Carys Bennett, Anthony D. Barnosky, Erle C. Ellis, Michael A. Ellis, Alejandro Cearreta, P.K. Haff, Juliana A. Ivar do Sul, Reinhold Leinfelder, J.R. McNeill, Eric Odada, Naomi Oreskes, Andrew Revkin, Daniel deB Richter, Will Steffen, Colin Summerhayes, James P. Syvitski, Davor Vidas, Michael Wagreich, Scott L. Wing, Alexander P. Wolfe & An Zhisheng (2016), "The Anthropocene: a conspicuous stratigraphical signal of anthropogenic changes in production and consumption across the biosphere", Earth's Future, DOI: 10.1002/2015EF000339

http://onlinelibrary.wiley.com/doi/10.1002/2015EF000339/abstract (http://onlinelibrary.wiley.com/doi/10.1002/2015EF000339/abstract)

Abstract: "Biospheric relationships between production and consumption of biomass have been resilient to changes in the Earth system over billions of years. This relationship has increased in its complexity, from localised ecosystems predicated on anaerobic microbial production and consumption, to a global biosphere founded on primary production from oxygenic photoautotrophs, through the evolution of Eukarya, metazoans, and the complexly networked ecosystems of microbes, animals, fungi and plants that characterise the Phanerozoic Eon (the last ~541 million years of Earth history). At present, one species, Homo sapiens, is refashioning this relationship between consumption and production in the biosphere with unknown consequences. This has left a distinctive stratigraphy of the production and consumption of biomass, of natural resources, and of produced goods. This can be traced through stone tool technologies and geochemical signals, later unfolding into a diachronous signal of technofossils and human bioturbation across the planet, leading to stratigraphically almost isochronous signals developing by the mid-20th century. These latter signals may provide an invaluable resource for informing and constraining a formal Anthropocene chronostratigraphy, but are perhaps yet more important as tracers of a biosphere state that is characterised by a geologically unprecedented pattern of global energy flow that is now pervasively influenced and mediated by humans, and which is necessary for maintaining the complexity of modern human societies."


Caption for: "Figure 1. Produced energy and the pattern of human population growth from 1750.  Utilization of these energy sources, together with the energy used by humans from  net primary production, is now approaching the entire energy available to the global ecosystem before human intervention (Barnosky, 2015). Key to colours: dark blue = coal; dark brown = oil; green = natural gas; purple = nuclear; light blue = hydro; orange brown = biomass (e.g. plants, trees). Data source from: http://www.theoildrum.com/node/8936 (http://www.theoildrum.com/node/8936)


Caption for: "Figure 4. A chronology of the human influence on patterns of primary and secondary production, and consumption, and on energy use from fossils fuels, from the late Pliocene to present. The figure identifies key factors in the human appropriation of primary and secondary production, via technology (and technofossils), migration (see Fig. 5), cultural evolution (from circa 70,000 years ago, culturally modern humans), forest clearance and farming, industrialization (and use of fossil fuels), and the consequent 20th – 21st century surge in population growth. These changes are reflected in physical strata through the manifestation of ‘Boundary A’, sensu Edgeworth et al. (2015), the diachronous bounding surface which marks the base of anthropogenic deposits, above which is a lithostratigraphic entity that contains novel materials and remains of domesticated animals and plants found as inclusions in anthropogenic ground - a direct signal of the increasing impact of humans. Right hand column shows selected and illustrative (but not exhaustive) major impacts on charcoal for iron smelting at his Shropshire Coalbrookedale factory, often viewed as the ‘birthplace’ of modern industry. Jethro Tull’s development of the horse drawn seed drill and hoe contributed to what is called the British Agricultural Revolution, and forms part of a broader continuum of agricultural developments beginning in medieval and early modern Europe and elsewhere."

Caption for: "Figure 5 The pattern of global migration exhibited by homo sapiens from the Paleolithic culture to present"
Title: Re: Early Anthropocene
Post by: AbruptSLR on March 17, 2016, 04:39:49 PM
In the linked reference Ruddiman et. al. (2016) provide more evidence of the Early Anthropocene theory:

W. F. Ruddiman, D. Q. Fuller, J. E. Kutzbach, P. C. Tzedakis, J. O. Kaplan, E. C. Ellis, S. J. Vavrus, C. N. Roberts, R. Fyfe, F. He, C. Lemmen & J. Woodbridge (15 February 2016), "Late Holocene climate: Natural or anthropogenic?", Review of Geophysics, DOI: 10.1002/2015RG000503

http://onlinelibrary.wiley.com/doi/10.1002/2015RG000503/full (http://onlinelibrary.wiley.com/doi/10.1002/2015RG000503/full)

Abstract: "For more than a decade, scientists have argued about the warmth of the current interglaciation. Was the warmth of the preindustrial late Holocene natural in origin, the result of orbital changes that had not yet driven the system into a new glacial state? Or was it in considerable degree the result of humans intervening in the climate system through greenhouse gas emissions from early agriculture? Here we summarize new evidence that moves this debate forward by testing both hypotheses. By comparing late Holocene responses to those that occurred during previous interglaciations (in section 2), we assess whether the late Holocene responses look different (and thus anthropogenic) or similar (and thus natural). This comparison reveals anomalous (anthropogenic) signals. In section 3, we review paleoecological and archaeological syntheses that provide ground truth evidence on early anthropogenic releases of greenhouse gases. The available data document large early anthropogenic emissions consistent with the anthropogenic ice core anomalies, but more information is needed to constrain their size. A final section compares natural and anthropogenic interpretations of the δ13C trend in ice core CO2."


See also:
http://www.realclimate.org/index.php/archives/2016/03/the-early-anthropocene-hypothesis-an-update/ (http://www.realclimate.org/index.php/archives/2016/03/the-early-anthropocene-hypothesis-an-update/)
Title: Re: Early Anthropocene
Post by: sidd on March 17, 2016, 07:22:21 PM
I am disappointed that the source for Fig 1 in the Williams paper is given as the (almost defunct) oildrum website, instead of the primary sources listed there. The Barnosky, Haberl and Erb papers in the references are very well worth reading, perhaps more so than Williams. I note that the list of authors for the Williams paper include both Revkin and Oreskes ...
Title: Re: Early Anthropocene
Post by: Laurent on March 22, 2016, 12:04:24 PM
Rate of carbon emissions put in context
http://www.bbc.com/news/science-environment-35867438 (http://www.bbc.com/news/science-environment-35867438)
Quote
We are now putting carbon into the atmosphere at a rate unprecedented since at least the age of the dinosaurs, scientists say.

The researchers have examined ocean sediments laid down during the so-called Palaeocene-Eocene Thermal Maximum - a dramatic warming event some 56 million years ago.

They find the amount of CO2 going into the air at its onset was four billion tonnes a year at most.

Today's figure is 10 times as big.

The work is published in the journal Nature Geoscience.

The PETM has been extensively studied by scientists because it is regarded as a possible "analogue" for what is happening on Earth now.

But the team argues that the scale of human-produced carbon emissions means that the lessons we could learn from the ancient event may actually have limited relevance.

"We have effectively entered an era of a no-analogue state, which represents a fundamental challenge to constraining future climate projections," they write in their paper.
Carbon pulse

The PETM was an extraordinary occurrence in Earth history.

Previous research has shown that ocean surface temperatures rose by about five degrees in a relatively short timescale, in the geological sense.

This phase of global warming drove a rapid turnover in species, both in the sea and on land.

CO2 concentration in the atmosphere very probably went above 1,000 parts per million by volume, compared with the 400ppm it stands at today.

The big pulse in emissions has been attributed to a range of factors, including a comet impact and prodigious volcanism. Some scientists suspect buried methane stores on the ocean floor were also released, amplifying the warming.

In their paper, Richard Zeebe and colleagues do not concern themselves with the cause; what they wanted to pin down was simply the rate of emissions.
Catch-up

The team achieved this by studying the remains of tiny marine organisms from the PETM known as Foraminifera.

The different types, or isotopes, of carbon and oxygen atoms in these fossils can be used to reconstruct likely CO2 levels and temperature 56 million years ago.

Analysis of this chemistry, together with some modelling work, suggests that temperature during the PETM rose in lock-step with carbon emissions.

Contrast this with the modern era where carbon emissions are rising so fast the "equilibrium temperature" lags behind.

Zeebe and colleagues calculate that it took at least 4,000 years for the PETM warming to take hold, with carbon going into the atmosphere at a rate of between 0.6 to 1.1 billion tonnes of carbon per annum.

At present, human emissions of CO2 are approaching 40 billion tonnes a year.
Time to cope

"If you go back to the [impactor] that killed off the dinosaurs (66 million years ago) - that was obviously an incredibly quick climate change," observed co-author Andy Ridgwell from Bristol University, UK.

"It wasn't driven by carbon emissions per say, but it was still an incredibly quick climate change. And so there has been a lot of searching around for what was the next most rapid event, and people have latched on to the PETM because it has all the characteristics of current warming and anthropogenic emissions - except it turns out the emissions in the PETM were actually an order of magnitude slower than they are today," he told BBC News.

Just how fast the planet might warm over the next two centuries is a topic of live debate because this likely be a big factor in how well species are able to adapt to changing conditions.

"The rate of change is as important as the magnitude of an event for determining particularly terrestrial ecosystem disruptions," Prof Ridgwell said.

Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
Title: Re: Early Anthropocene
Post by: AbruptSLR on March 26, 2016, 06:24:24 PM
The linked reference discusses various frameworks (including those in different disciplines) for considering the Anthropocene as a rupture:

Clive Hamilton (February 22, 2016), "The Anthropocene as rupture", The Anthropocene Review, doi: 10.1177/2053019616634741

http://anr.sagepub.com/content/early/2016/02/19/2053019616634741.abstract (http://anr.sagepub.com/content/early/2016/02/19/2053019616634741.abstract)

Abstract: "I argue that Earth System science – a recent paradigm shift in the earth and life sciences (Hamilton C and Grinevald J (2015) Was the Anthropocene anticipated? The Anthropocene Review 2(1): 59–72) – named the Anthropocene as the very recent rupture in Earth history arising from the impact of human activity on the Earth System as a whole. Many have mistakenly treated the new concept of the Earth System as if it were equivalent to ‘the landscape’, ‘ecosystems’ or ‘the environment’. The new paradigm of Earth System science is erroneously understood as no more than a variation or development of established ecological sciences. Various attempts to invent new starting dates for the new epoch are based on these misconceptions, as are a number of arguments deployed to reject the Anthropocene altogether. In this context I consider the early Anthropocene hypothesis, three readings of the Anthropocene as instances of ecosystem change, and the notion of the ‘good Anthropocene’. Using this frame I also assess the arguments of those who do not accept the idea of the new epoch. I defend the view that disciplines other than Earth System science distort the idea of the Anthropocene when they read it through their own lenses."
Title: Re: Early Anthropocene
Post by: Laurent on April 04, 2016, 10:19:47 AM
About absorbing non CO2 green house gazes :
http://www.centerforcarbonremoval.org/blog/2016/4/2/nonco2ghgremoval (http://www.centerforcarbonremoval.org/blog/2016/4/2/nonco2ghgremoval)

The data they use is about CO2e on 100 years time frame but when will scientists start to write (not talk) about CO2e on 10 years time frame, plus they use old data for CH4 for example, 28 instead of 34 (time green house effect compare to CO2) on 100 years time frame in the last IPCC report. The reality is that methane has increased 250% for 200 years, if in laboratory we have reduction in reality that is not the case, so we must take into account a 10 years (20 if you want) frame.
Title: Re: Early Anthropocene
Post by: Laurent on April 19, 2016, 06:35:03 PM
Study: humans have caused all the global warming since 1950
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2016/apr/19/study-humans-have-caused-all-the-global-warming-since-1950 (http://www.theguardian.com/environment/climate-consensus-97-per-cent/2016/apr/19/study-humans-have-caused-all-the-global-warming-since-1950)

Quote
A new study published in Climate Dynamics has found that humans are responsible for virtually all of the observed global warming since the mid-20th century. It’s not a novel result – in fact, most global warming attribution studies have arrived at the same general result – but this study uses a new approach.
Title: Re: Early Anthropocene
Post by: AbruptSLR on June 18, 2016, 10:09:52 AM
The linked reference discusses the synergistic roles of climate warming & human occupation in Patagonian megafaunal extinctions in a narrow phase 12,280 ± 110 years ago:

Jessica L. Metcalf, et. al. (17 Jun 2016), "Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions during the Last Deglaciation", Science Advances, Vol. 2, no. 6, e1501682, DOI: 10.1126/sciadv.1501682

http://advances.sciencemag.org/content/2/6/e1501682 (http://advances.sciencemag.org/content/2/6/e1501682)

Abstract: "The causes of Late Pleistocene megafaunal extinctions (60,000 to 11,650 years ago, hereafter 60 to 11.65 ka) remain contentious, with major phases coinciding with both human arrival and climate change around the world. The Americas provide a unique opportunity to disentangle these factors as human colonization took place over a narrow time frame (~15 to 14.6 ka) but during contrasting temperature trends across each continent. Unfortunately, limited data sets in South America have so far precluded detailed comparison. We analyze genetic and radiocarbon data from 89 and 71 Patagonian megafaunal bones, respectively, more than doubling the high-quality Pleistocene megafaunal radiocarbon data sets from the region. We identify a narrow megafaunal extinction phase 12,280 ± 110 years ago, some 1 to 3 thousand years after initial human presence in the area. Although humans arrived immediately prior to a cold phase, the Antarctic Cold Reversal stadial, megafaunal extinctions did not occur until the stadial finished and the subsequent warming phase commenced some 1 to 3 thousand years later. The increased resolution provided by the Patagonian material reveals that the sequence of climate and extinction events in North and South America were temporally inverted, but in both cases, megafaunal extinctions did not occur until human presence and climate warming coincided. Overall, metapopulation processes involving subpopulation connectivity on a continental scale appear to have been critical for megafaunal species survival of both climate change and human impacts."


See also:
http://www.sciencemag.org/news/2016/06/rising-temperatures-and-humans-were-deadly-combo-ancient-south-american-megafauna (http://www.sciencemag.org/news/2016/06/rising-temperatures-and-humans-were-deadly-combo-ancient-south-american-megafauna)

Extract: "now, most researchers think that people were already in the Americas by at least 15,000 years ago. That means that people and megafauna actually coexisted for a few thousand years before the mass extinctions began. What changed to drive these animals out of existence?
To find the missing ingredient, Alan Cooper, an evolutionary biologist at the University of Adelaide in Australia, radiocarbon dated nearly 100 fossils from Patagonia and sequenced their mitochondrial DNA, genes found in the power plants of cells and passed down only from the mother. When he lined up their ages with global climate records, he noticed a pattern: Many species of megafauna seemed to disappear during a period of extreme warming around 12,300 years ago, Cooper and his team write today in Science Advances. Ice cores from Greenland and West Antarctica suggest that average global temperatures quickly shot up during that time. Patagonia warmed by about 2°C over 1000 years, and the effects were devastating: All but one of the species Cooper studied went extinct."
Title: Re: Early Anthropocene
Post by: AbruptSLR on June 18, 2016, 10:22:56 AM
The linked reference is related to the research cited in my immediate prior post, in that "Cooper et al. report a close relationship between Pleistocene megafaunal extinction events and rapid warming events at the start of interstadial periods. Their analysis strengthens the case for climate change as the key driver of megafaunal extinctions, with human impacts playing a secondary role."

Alan Cooper, Chris Turney, Konrad A. Hughen, Barry W. Brook, H. Gregory McDonald & Corey J. A. Bradshaw, (07 Aug 2015), "Abrupt warming events drove Late Pleistocene Holarctic megafaunal turnover", Science, Vol. 349, Issue 6248, pp. 602-606, DOI: 10.1126/science.aac4315


http://science.sciencemag.org/content/349/6248/602 (http://science.sciencemag.org/content/349/6248/602)

Abstract: "The mechanisms of Late Pleistocene megafauna extinctions remain fiercely contested, with human impact or climate change cited as principal drivers. We compared ancient DNA and radiocarbon data from 31 detailed time series of regional megafaunal extinctions and 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 or extinction of major genetic clades or species of megafauna. The presence of many cryptic biotic transitions before 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."
Title: Re: Early Anthropocene
Post by: AbruptSLR on August 18, 2016, 10:58:48 PM
Clive Hamilton authored the linked article entitled: "The Anthropocene Belongs to Earth System Science"; in which he elaborates on the meaning of the new formal definition (starting after 1945) of the Anthropocene, as opposed to researchers who have supported earlier starting dates:

https://theconversation.com/the-anthropocene-belongs-to-earth-system-science-64105 (https://theconversation.com/the-anthropocene-belongs-to-earth-system-science-64105)

Extract: "The idea of the Anthropocene was conceived by Earth System scientists to capture the very recent rupture in Earth history arising from the impact of human activity on the Earth System as a whole.

The Anthropocene is not defined by the broadening impact of humans on “the environment”, “ecosystems” or “the landscape”, that is, as an extension of what humans have been doing for centuries or millennia. It is defined by human interference, over recent decades, in the functioning of the Earth System, that is, the planet as a whole understood as a unified, complex, evolving system beyond the sum of its parts.
The components of the Earth System are integrated so that climate change, for example, affects not just the atmosphere but also the functioning of the hydrosphere, the cryosphere, the biosphere and even the lithosphere. (Arguably, anthropogenic climate change is more of an oceanic than an atmospheric phenomenon.) Only in recent decades, or at most the last two centuries, have humans begun to change the way the Earth System operates."

See also:
http://www.nature.com/articles/536251a.epdf?author_access_token=Jy5IKcJrga-YuJ4q7tFbKNRgN0jAjWel9jnR3ZoTv0PDpktllxwIwQQg8F9lEF1veN4vxSN6JcLcVPlVuG0G7iVaHH4s_UfpLq-O3Asm_c0A5-r_nzOYJtz6SA22zhLf (http://www.nature.com/articles/536251a.epdf?author_access_token=Jy5IKcJrga-YuJ4q7tFbKNRgN0jAjWel9jnR3ZoTv0PDpktllxwIwQQg8F9lEF1veN4vxSN6JcLcVPlVuG0G7iVaHH4s_UfpLq-O3Asm_c0A5-r_nzOYJtz6SA22zhLf)

Title: Re: Early Anthropocene
Post by: AbruptSLR on August 24, 2016, 09:49:27 PM
The definition of the Anthropocene may soon become official:

http://www.sciencemag.org/news/2016/08/atomic-bombs-and-oil-addiction-herald-earth-s-new-epoch-anthropocene (http://www.sciencemag.org/news/2016/08/atomic-bombs-and-oil-addiction-herald-earth-s-new-epoch-anthropocene)

Extract: "Just after World War II, when the atomic bombs fell and our thirst for coal and oil became a full-blown addiction, Earth entered the Anthropocene, a new geologic time when humanity’s environmental reach left a mark in sediments worldwide. That’s the majority conclusion of the Anthropocene Working Group, a collection of researchers that has spent the past 7 years quietly studying whether the term, already popular, should be submitted as a formal span of geologic time.

After tallying votes this month, the group has decided to propose the postwar boom of the late 1940s and early 1950s as the Anthropocene’s start date. The group will ask the International Commission on Stratigraphy (ICS), the bureaucracy that governs geologic time, to recognize the Anthropocene as a series, the stratigraphic equivalent of an epoch, on par with the Holocene and Pleistocene that preceded it. Colin Waters, the group’s secretary and a geologist at the British Geological Survey in Keyworth, will reveal the group’s recommendations on 29 August at the International Geological Congress in Cape Town, South Africa."
Title: Re: Early Anthropocene
Post by: AbruptSLR on October 19, 2016, 03:30:20 AM
Along the way to 9595 posts, I kept remembering lyrics from: "In The Year 2525", by Zager & Evans


Quote:

"In the year 9595, I'm kinda wonderin' if Man is gonna be alive.
He's taken everything this old Earth can give, and he ain't put back nothin', whoa-whoa...,
Now it's been 10,000 years, Man has cried a billion tears,
For what, he never knew. Now man's reign is through.
But through eternal night, The twinkling of starlight.
So very far away, Maybe it's only yesterday."
 
If one considers that the Early Anthropocene began with a combination of megafaunal extinctions, slash & burn agriculture & methane emissions from rice cultivation some 10,000 years ago (see the attached plots); then maybe it will have been 10,000 years of man's reign over the environment between 2050 & 2060.

Read more lyrics at:
http://www.metrolyrics.com/in-the-year-2525-lyrics-zager-and-evans.html (http://www.metrolyrics.com/in-the-year-2525-lyrics-zager-and-evans.html)


Edit: W.R.T. Megafauna extinctions see Replies: #21, 24, 25, 37, 38, 62 & 63,
Title: Re: Early Anthropocene
Post by: budmantis on October 19, 2016, 07:12:45 AM
ASLR: When you reach 10,000 posts will you be elevated to ASIF "deity" or is ASIF royalty as far as it goes? All kidding aside, I've enjoyed your prodigious and very detailed contributions to the Forum.
Title: Re: Early Anthropocene
Post by: AbruptSLR on January 24, 2017, 12:34:19 AM
The linked open access reference supports the idea of an early anthropocene:

van der Kaars et. al. (2017), "Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia", Naturel Communications, doi:10.1038/nconns14142

http://www.nature.com/articles/ncomms14142 (http://www.nature.com/articles/ncomms14142)


See also
http://www.vocativ.com/395348/ancient-poop-humans-drove-australias-giant-animals-extinct/ (http://www.vocativ.com/395348/ancient-poop-humans-drove-australias-giant-animals-extinct/)

Title: Re: Early Anthropocene
Post by: jai mitchell on April 08, 2017, 08:30:47 PM
This is an excellent resource that describes the ins and outs of the early glaciation offset hypothesis by ruddiman.  just found it and wanted to share.

http://environmentalscience.oxfordre.com/view/10.1093/acrefore/9780199389414.001.0001/acrefore-9780199389414-e-192 (http://environmentalscience.oxfordre.com/view/10.1093/acrefore/9780199389414.001.0001/acrefore-9780199389414-e-192)

some images follow

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fenvironmentalscience.oxfordre.com%2Fview%2F10.1093%2Facrefore%2F9780199389414.001.0001%2Facrefore-9780199389414-e-192-graphic-007-full.jpg&hash=3eae3d105d30d2ba2c86324e215fdb15)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fenvironmentalscience.oxfordre.com%2Fview%2F10.1093%2Facrefore%2F9780199389414.001.0001%2Facrefore-9780199389414-e-192-graphic-008-full.jpg&hash=dd85edf34cc9a983b7da0acacc525918)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fenvironmentalscience.oxfordre.com%2Fview%2F10.1093%2Facrefore%2F9780199389414.001.0001%2Facrefore-9780199389414-e-192-graphic-012-full.jpg&hash=45841cc60e4c9d01da1b16e32c5bec6f)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fenvironmentalscience.oxfordre.com%2Fview%2F10.1093%2Facrefore%2F9780199389414.001.0001%2Facrefore-9780199389414-e-192&hash=a8b1d42d83e24b2d9bab02c10a8fb53c)
Title: Re: Early Anthropocene
Post by: jai mitchell on May 26, 2017, 05:12:52 PM
I am calling this here as "beaver force" after the Clovis period North Americans who believed that there were beavers underneath the Foxe-Laurentide Ice Dome that lifted it up to cause sudden, unpredictable (Jokullhaup) floods.

VeilAlbertKallio,

I have not heard of any oral tradition history from the Clovis people, do you mean another tribe or group of peoples in the early americas?  do you have a source for this information?

Title: Re: Early Anthropocene
Post by: guygee on May 27, 2017, 03:01:27 PM
I am calling this here as "beaver force" after the Clovis period North Americans who believed that there were beavers underneath the Foxe-Laurentide Ice Dome that lifted it up to cause sudden, unpredictable (Jokullhaup) floods.

VeilAlbertKallio,

I have not heard of any oral tradition history from the Clovis people, do you mean another tribe or group of peoples in the early americas?  do you have a source for this information?
Indeed, VeilAlbertKallio is undoubtedly mistaken about any historical knowledge of Clovis-period oral tradition; they are only known from their stone artifacts and evidence of habitation from archaeological sites. One could fill pages of references to peer-reviewed journal articles on this point, but the bare outline is given in this blog post by  anthropologist Greg Laden in light of the highly debated and dubious claims for evidence of hominid activity in the Americas in the previous inter-glacial period, which I found to be interesting, http://scienceblogs.com/gregladen/2017/05/02/about-that-130000-human-occupation-in-california/?utm_source=widgets (http://scienceblogs.com/gregladen/2017/05/02/about-that-130000-human-occupation-in-california/?utm_source=widgets)
P.S. For those interested in more detail, see this review paper:
RM Ellsworth, "The Paleoindian Occupation of the Americas"
https://anthromuseum.missouri.edu/minigalleries/clovistools/EllsworthPaleoindianPaper.pdf (https://anthromuseum.missouri.edu/minigalleries/clovistools/EllsworthPaleoindianPaper.pdf)
quote: "In contrast to the European Paleolithic archaeological record from the same time period, the Clovis record is largely barren in terms of non-lithic, organic artifactual remains." Further, "Other than a few scratch marks generally accepted to be human-made modifications, there is no portable artwork, carved figurines, cave paintings or petroglyphs that are clearly and definitively dated to the Clovis era..."
Title: Re: Early Anthropocene
Post by: VeliAlbertKallio on May 28, 2017, 05:39:57 AM
I apologize for taking a substantial time to respond. Despite a very comprehensive system how I keep my science library, it has over 40,000 items and even with my best efforts tracing records takes time and sometimes things simply can also get lost. However, I am now fortunately in a position to answer to you with some considerable. It is also to my understanding the position accepted by the museum of the said nation and presented there as a fact by the said nation.

First of all, I am pulling things out of my memory and there is always a possibility that inaccuracies can arise over time, but for the most part, I think my mental image was not too departed when I put forward the idea of Clovis people associating Jokullhaups from the Foxe Laurentide Ice dome, or the Laurentide Ice Sheet glacial lakes with 'bearver trickster' imaginary creatures under its ice.

Secondly, I labelled it as the Clovis period for the reason that it is the earliest culture that is widely recognized and geospatially covering the territories involved and generally understood as the source population of the later Native American Indians. The association to the collapse of the Lake Agassiz described associates the people of the period to the Clovis which is not the way the people contemporarily called of themselves. Thus Lage Agassiz time stamp associates it to Clovis.

Thirdly, the association of the event in question, the beaver-trickster (phenomenon) unleashing the collapse of Lake Agassiz took in a place from where these tribe had resided, Mackinac Island. The habitation of the area is through the Archaic Period hunter-gatherers of Clovis culture who "tended to settle along rivers and lakes in both coastal and interior regions for maximum access to food resources." Fiedel, Stuart J. (1992). "Prehistory of the Americas, 2nd Edition." Cambridge Univeristy Press. Then the Woodland Period follows these Archaic hunter-gatherers (but preceded the agriculturalist Mississippian cultures). The Middle Woodland period cultures of Hopewellian traditions covers St. Lawrence and Missisippian basins. The late Woodland Indians became known as the Menominee (who were forcibly moved from Mackinac Island by the US settlers who are the people with the recollection about the sudden collapse of Lake Agassiz and it becoming the present-day Lake Michigan and other lesser lakes:

"In Menominee mythology, Manabus, the trickster, "fired by his lust for revenge" shot two underground gods when the gods were at play. When they all dived into the water, a huge flood arose. "The water rose up .... It knew very well where Manabus had gone." He runs, he runs; but the water, coming [to McKenzie Island] from Lake Michigan, chases him faster and faster, even as he runs up a mountain and climbs to the top of the lofty pine at its peak. Four times he begs the tree to grow just a little more, and four times it obliges until it can grow no more. But the water keeps climbing "up, up, right to his chin, and there it stopped": there was nothing but water stretching out to the horizon. And then Manabus, helped by diving animals, and especially the bravest of all, the Muskrat [beaver], creates the world [the Great Lakes area] as we know it today." http://en.wikipedia.org/wiki/File:Mackinac_Island_topographic_map-en.svg (http://en.wikipedia.org/wiki/File:Mackinac_Island_topographic_map-en.svg)

"Ancient Waterfall Discovered Off Mackinac Island's Shoreline
>
 An ancient 100-foot waterfall off the shore of Mackinac Island was discovered underwater last week by the crew aboard the training and research vessel The Pride of Michigan. They came across the 10,000-year-old waterfall while taking soundings in the area. The waterfall is part of an ancient and now-submerged river, called the Mackinac Channel, that flowed through the Straits before the existence of Lake Michigan and Lake Huron. "It is not as large as Niagara," said Captain Luke Clyburn, "but it is a very, very significant waterfall." Now lying 110 feet beneath the surface of Lake Huron, just off the east shore of Mackinac Island, the site shows that water flowed from west to east along the channel before plunging nearly 100 feet from a limestone cliff. Soundings recorded Thursday, August 16, revealed the cliff and sharp drop in the riverbed.
>
 "This is a major find for this area," said Captain Clyburn. "To be able to come in and say, 'Here was a waterfall,' it kind of brings a name to this whole river channel." From research in the area two years ago, Captain Clyburn speculated that a rapids or a waterfall might exist. While testing new sounding equipment Thursday, his suspicions of a waterfall were confirmed based on readings from the site. "We'll be back up doing more work in this area," he said, "now that we've pinpointed the waterfall." In conjunction with training for U.S. Naval Sea Cadets, the ship conducts underwater research and is on a mission to learn about and find areas inhabited by cultures 10,000 years ago.
>
The discovery of the waterfall on the former 80-mile-long river, said Captain Clyburn, increases the probability that people lived nearby, and it increases the chances of finding evidence of them on future dives. The existence of the ancient river channel was found on soundings taken in the 1930s and later confirmed when spruce stumps discovered about 120 feet beneath the surface of the Straits were carbon-dated to 10,000 years ago. "
http://www.mackinacislandnews.com/news/2007-08-25/Front_page/003.html (http://www.mackinacislandnews.com/news/2007-08-25/Front_page/003.html)

http://en.wikipedia.org/wiki/Mackinac_Island#cite_note-Waterfall-29 (http://en.wikipedia.org/wiki/Mackinac_Island#cite_note-Waterfall-29)
http://www.therepublic.com/view/story/1fff893f54ba4e7d9165f8de953cba78/MI--Mackinac-Island-Remains/ (http://www.therepublic.com/view/story/1fff893f54ba4e7d9165f8de953cba78/MI--Mackinac-Island-Remains/)
http://www.9and10news.com/Category/Story/?id=309192&cID=1 (http://www.9and10news.com/Category/Story/?id=309192&cID=1)



I am calling this here as "beaver force" after the Clovis period North Americans who believed that there were beavers underneath the Foxe-Laurentide Ice Dome that lifted it up to cause sudden, unpredictable (Jokullhaup) floods.

VeilAlbertKallio,

I have not heard of any oral tradition history from the Clovis people, do you mean another tribe or group of peoples in the early americas?  do you have a source for this information?
Title: Re: Early Anthropocene
Post by: VeliAlbertKallio on May 28, 2017, 06:27:09 AM
The site, Mackinac Island, where the recollection described comes is the precise point where the Lake Agassiz broke waters and redirected the Laurentide Ice Sheet drainage from the River Missisippi to the Gulf of St Lawrence. Menominee were forcibly removed from their ancient habitat here in the 19th century. (See the citations and references on the previous post).
Title: Re: Early Anthropocene
Post by: jai mitchell on May 28, 2017, 07:45:15 AM
Thank you, that was an excellent and insightful read! 
Title: Re: Early Anthropocene
Post by: Hyperion on May 28, 2017, 09:40:21 AM
I wouldn't be so sure that humans were not in the Americas in the last interglacial. Though perhaps not homo sap. These ones have up to 2 or 3 times as big a brain as us. Though its not just in the Americas that the conehead type is found. There is also the matter of raised garden type geoglyphs of very large scale in the Altiplano with glacial period sediment fans over them. Not to mention extensive submerged Megalithic structures in the Caribbean etc.

The Mitochondrial  DNA maps show a Ice age civilisation spanning the tropical Pacific. Not so the Y chromosome ones. The men tend to invade new territories while the women stay put.
Title: Re: Early Anthropocene
Post by: bbr2314 on May 28, 2017, 09:54:56 AM
I wouldn't be so sure that humans were not in the Americas in the last interglacial. Though perhaps not homo sap. These ones have up to 2 or 3 times as big a brain as us. Though its not just in the Americas that the conehead type is found. There is also the matter of raised garden type geoglyphs of very large scale in the Altiplano with glacial period sediment fans over them. Not to mention extensive submerged Megalithic structures in the Caribbean etc.

The Mitochondrial  DNA maps show a Ice age civilisation spanning the tropical Pacific. Not so the Y chromosome ones. The men tend to invade new territories while the women stay put.
I believe those head shapes were caused by molding via whatever torturous devices they had, but more important re: humans/hominids in the Americas is this recent discovery which pushes arrival back to 130K yrs ago!

https://arstechnica.com/science/2017/04/unknown-humans-were-in-california-130000-years-ago-say-scientists/
Title: Re: Early Anthropocene
Post by: Hyperion on May 28, 2017, 11:36:09 AM
Certainly it was not head binding. Though that is a common claim, stemming from the practice surviving culturally in some places from times when mothers wanted their kids to look like they were the offspring of these chaps. One that must have had its head bound in the womb below. ::)

And I wouldn't be too sure we are the first with Nuclear, Space technology etc. Cultures from China to the Americas, to Scandinavia talk of artificial suns in orbit around the earth and mars and moons of the giant planets. And throwing them at their enemies on the other side of the world. Engraving of them doing that attached also.

Heres some Flood stories attached. just a small sample.
I think the Welsh one sounds like a Agassiz Event: 8)

 The lake of Llion burst, flooding all lands. Dwyfan and Dwyfach escaped eastward in a mastless ship with pairs of every sort of living creature. They landed in Prydain (Britain) and repopulated the world. [Gaster, pp. 92-93]
Title: Re: Early Anthropocene
Post by: johnm33 on May 28, 2017, 07:46:25 PM
Brien Foerster has long studied those people with giant skulls, somewhere on his site are photos of a foetus with the same skull type. https://hiddenincatours.com/ here it is. https://hiddenincatours.com/two-american-doctors-examine-elongated-skull-mother-baby-fetus-bolivia/
Title: Re: Early Anthropocene
Post by: guygee on May 28, 2017, 11:34:30 PM
I wouldn't be so sure that humans were not in the Americas in the last interglacial. Though perhaps not homo sap. These ones have up to 2 or 3 times as big a brain as us. Though its not just in the Americas that the conehead type is found. There is also the matter of raised garden type geoglyphs of very large scale in the Altiplano with glacial period sediment fans over them. Not to mention extensive submerged Megalithic structures in the Caribbean etc.

The Mitochondrial  DNA maps show a Ice age civilisation spanning the tropical Pacific. Not so the Y chromosome ones. The men tend to invade new territories while the women stay put.
Nobody is "sure", but as G. Laden points out in the link I posted, there is a lack of evidence.

As for contact between Austronesian peoples with the Americas, I think there is strong evidence, not just from human DNA studies but also from plant DNA, e.g. pre-European existence of coconuts on the west coast of Central America, sweet potatoes in the Cook Islands. But again, we do not know when that contact took place, whether it was a founding event or much later. "Invading men" may travel without women (although I think that is a culturally-biased assumption) but that strategy would surely fail for colonists.

 There is quite a lively debate ongoing between linguists, geneticists, archeologists and anthropologists on these issues, and nothing has been settled.  I am none of these, count me in as an interested observer of these sciences, with an emphasis on Science.

There is no 'scientific consensus' as there is with AGW on the origin and details of the first peopling of the Americas.
Title: Re: Early Anthropocene
Post by: guygee on May 29, 2017, 12:26:21 AM
Brien Foerster has long studied those people with giant skulls, somewhere on his site are photos of a foetus with the same skull type. https://hiddenincatours.com/ here it is. https://hiddenincatours.com/two-american-doctors-examine-elongated-skull-mother-baby-fetus-bolivia/
Further reading on Brien Foerster: https://badarchaeology.wordpress.com/tag/brien-foerster/ (https://badarchaeology.wordpress.com/tag/brien-foerster/)
Title: Re: Early Anthropocene
Post by: AbruptSLR on June 15, 2017, 01:26:57 AM
The linked reference indicates that climate model projections of the Holocene were/are more accurate than Shaun Marcott's reconstruction of this period.

Jonathan L. Baker, Matthew S. Lachniet, Olga Chervyatsova, Yemane Asmerom & Victor J. Polyak (2017), "Holocene warming in western continental Eurasia driven by glacial retreat and greenhouse forcing", Nature Geoscience, Volume: 10, Pages: 430–435, doi:10.1038/ngeo2953

http://www.nature.com/ngeo/journal/v10/n6/full/ngeo2953.html (http://www.nature.com/ngeo/journal/v10/n6/full/ngeo2953.html)
&
http://www.readcube.com/articles/10.1038/ngeo2953 (http://www.readcube.com/articles/10.1038/ngeo2953)

Abstract: "The global temperature evolution during the Holocene is poorly known. Whereas proxy data suggest that warm conditions prevailed in the Early to mid-Holocene with subsequent cooling, model reconstructions show long-term warming associated with ice-sheet retreat and rising greenhouse gas concentrations. One reason for this contradiction could be the under-representation of indicators for winter climate in current global proxy reconstructions. Here we present records of carbon and oxygen isotopes from two U–Th-dated stalagmites from Kinderlinskaya Cave in the southern Ural Mountains that document warming during the winter season from 11,700 years ago to the present. Our data are in line with the global Holocene temperature evolution reconstructed from transient model simulations. We interpret Eurasian winter warming during the Holocene as a response to the retreat of Northern Hemisphere ice sheets until about 7,000 years ago, and to rising atmospheric greenhouse gas concentrations and winter insolation thereafter. We attribute negative δ18O anomalies 11,000 and 8,200 years ago to enhanced meltwater forcing of North Atlantic Ocean circulation, and a rapid decline of δ13C during the Early Holocene with stabilization after about 10,000 years ago to afforestation at our study site. We conclude that winter climate dynamics dominated Holocene temperature evolution in the continental interior of Eurasia, in contrast to regions more proximal to the ocean."

See also:

"New research may resolve a climate ‘conundrum’ across the history of human civilization"

https://www.skepticalscience.com/research-resolve-holocene-conundrum.html (https://www.skepticalscience.com/research-resolve-holocene-conundrum.html)

Extract: "… the overall temperature change during the Holocene matched pretty well in reconstructions and models, but the pattern didn’t. The best proxy reconstruction from a 2013 paper led by Shaun Marcott estimated more warming than models from 12,000 to 7,000 years ago. Then over the past 7,000 years, Marcott’s reconstruction estimated about 0.5°C cooling while model simulations showed the planet warming by about the same amount.

A new paper led by Jonathan Baker may help to resolve that discrepancy. The scientists examined stalagmites from a cave in the southern Ural Mountains of Russia. The ratio of oxygen isotopes in the stalagmites can be used to estimate past winter temperatures. The Marcott study had one known shortcoming – the proxy temperature data they used mostly represented the summer season. And as Baker explained, changes in the Earth’s orbital cycles have caused summer cooling and winter warming during the Holocene:

Because our orbit is elliptical, we’re not always the same distance from the sun. About 10,000 years ago, Earth was closest to the sun during summer and farthest during winter. Today it is the opposite. Based on this variable alone, we would expect winter warming and summer cooling in the northern hemisphere (and vice versa in the southern hemisphere) over the last 10,000 years."

During the period from 15,000 to 7,000 years ago, temperatures were rising because large ice sheets were disappearing. That was especially true in the summer because back then, the Earth was closest to the sun during that season. So the Marcott temperature reconstruction, which was predominantly based on summer temperature proxies, estimated a lot of warming from 15,000 to 7,000 years ago (more than in model simulations), then a small cooling thereafter, while models simulate a slight warming over the past 7,000 years due to a slow rise in greenhouse gases.

The stalagmite data in the Baker study show that winter temperatures behaved differently and can reconcile the discrepancies between the Marcott reconstruction and model simulations. This suggests that the climate models are right – Earth’s surface temperature warmed rapidly at the end of the last ice age, from about 17,000 to 7,000 years ago, then the rate of warming slowed as the climate stabilized. However, it didn’t reverse into a cooling trend, because atmospheric greenhouse gas levels were rising.
Title: Re: Early Anthropocene
Post by: pileus on June 15, 2017, 07:05:37 AM
I wouldn't be so sure that humans were not in the Americas in the last interglacial. Though perhaps not homo sap. These ones have up to 2 or 3 times as big a brain as us. Though its not just in the Americas that the conehead type is found. There is also the matter of raised garden type geoglyphs of very large scale in the Altiplano with glacial period sediment fans over them. Not to mention extensive submerged Megalithic structures in the Caribbean etc.

The Mitochondrial  DNA maps show a Ice age civilisation spanning the tropical Pacific. Not so the Y chromosome ones. The men tend to invade new territories while the women stay put.

Was a bit skeptical about the turn this thread took in late May, but in the spirit of keeping an open mind upon further research it does appear that several specimens of these early Americans survived into the 1970s.

Title: Re: Early Anthropocene
Post by: AbruptSLR on August 19, 2017, 06:42:57 PM
The linked reference indicates that evidence for an early Anthropocene date takes many different forms, including increase sedimentation in the Dead Sea:

Title: "Earliest human-made climate change took place 11,500 years ago"

https://www.sciencedaily.com/releases/2017/06/170605110059.htm (https://www.sciencedaily.com/releases/2017/06/170605110059.htm)

Extract: "A new Tel Aviv University study has uncovered the earliest known geological indications of humanmade climate change from 11,500 years ago. Within a core sample retrieved from the Dead Sea, researchers discovered basin-wide erosion rates dramatically incompatible with known tectonic and climatic regimes of the period recorded."

See also:

Yin Lu, Nicolas Waldmann, Dani Nadel, Shmuel Marco. Increased sedimentation following the Neolithic Revolution in the Southern Levant. Global and Planetary Change, 2017; 152: 199 DOI: 10.1016/j.gloplacha.2017.04.003

&

https://www.sciencedaily.com/news/fossils_ruins/early_climate/ (https://www.sciencedaily.com/news/fossils_ruins/early_climate/)
Title: Re: Early Anthropocene
Post by: AbruptSLR on December 17, 2017, 05:23:32 PM
Ruddiman (2017) adds geographic evidence for the early anthropogenic hypothesis:

William Ruddiman (2017), "Geographic evidence of the early anthropogenic hypothesis", Anthropocene, https://doi.org/10.1016/j.ancene.2017.11.003

http://www.sciencedirect.com/science/article/pii/S2213305417300504?utm_content=buffer4f59e&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Abstract: "The early anthropogenic hypothesis claims that millennia ago farming began to transform landscapes sufficiently to emit greenhouse gases and extend the natural warmth of the current interglaciation that had been initiated by orbital variations. Part of the debate over the hypothesis during the last dozen years has centered on determining the best orbital analog to the Holocene among prior interglaciations, all of which must have been natural (non-anthropogenic) in origin. Since 2009, dozens of papers have assembled physical geographic evidence that points to the kind of large early agricultural impacts posed by the early anthropogenic hypothesis. These new findings include: pollen and archaeological evidence of carbon dioxide (CO2)-emitting early forest clearance in Europe and China, along with archaeobotanical and archaeological evidence of methane (CH4)-emitting rice irrigation and livestock tending across southern Asia. In addition, mapping of 14C-dated peat deposits has revealed an important CO2 sink of 12C-enriched terrestrial carbon during the last 7000 years that countered the δ13CO2 imprint of emissions from early deforestation. This viewpoint article provides a current perspective on this ongoing debate in the context of these recent findings."
Title: Re: Early Anthropocene
Post by: AbruptSLR on February 02, 2018, 04:44:55 PM
The linked reference adds information about the early Holocene/Anthropocene:

Marsicek et al. (2018), "Reconciling divergent trends and millennial variations in Holocene temperatures", Nature, doi:10.1038/nature25464

http://www.nature.com/articles/nature25464.epdf?referrer_access_token=tmj4qyALYcUtbsXwmRfBDdRgN0jAjWel9jnR3ZoTv0OajynsiI4jXncpU7EXgTD5wtNO6KcGzz2TL79FU1hfvNZLGYihDDKFxMAC-ScTr8Ni4_yGK1hSAjnKpIhlXldty34TemiGWYOq43nqFFVTAsC513276OenLhbbl20ABswN6jRSoiwtZbl30ANNbojj1M0ka6BZ_Ix9kDe7iwDcE5idmonYzLUNHxXpokolZDvjXAMfqLOxMqrWVg_-t6bVKgG5XAklpNKBPd2BfUzF5yohgGAVQbAzMOw7gnODu77y9j3QcM5tgG8KVS_v1rT8&tracking_referrer=thinkprogress.org

Overall, our reconstructions indicate that the on-going warming today would have started from a baseline approximately 0.5 °C higher  than observed had millennial-to-centennial-scale variations not produced cooling over the past two millennia that deviated from Holocene trends. The reconstructions support the ability of models such as CCSM3 to capture large-scale climate responses to external forcing and important internal dynamics. Although additional transient climate simulations and new, detailed palaeoclimate records are needed to further understand the processes involved, millennial-to-centennial-scale climate variability such as occurred during the Holocene could continue to amplify or modulate future temperature trends."
Title: Re: Early Anthropocene
Post by: AbruptSLR on April 20, 2018, 01:43:51 AM
These finding make sense to me:

Title: "New Study Says Ancient Humans Hunted Big Mammals To Extinction"

https://www.npr.org/sections/thetwo-way/2018/04/19/604031141/new-study-says-ancient-humans-hunted-big-mammals-to-extinction

Extract: " Over the past 125,000 years, the average size of mammals on the Earth has shrunk. And humans are to blame.

That's the conclusion of a new study of the fossil record by paleo-biologist Felisa Smith of the University of New Mexico."

See also:

http://science.sciencemag.org/content/360/6386/310
Title: Re: Early Anthropocene
Post by: sidd on April 20, 2018, 02:58:44 AM
Yes, i'm afraid we killed everything, and probably ate only a small fraction of what we killed. As we do today. I attach fig 3 from the Smith paper showing the rapid killing when humans appeared. Bear in mind the y axis is logarithmic, making it even more shocking.

sidd
Title: Re: Early Anthropocene
Post by: AbruptSLR on May 10, 2018, 11:10:46 PM
Terry & JMP,

Apparently, as this will define a new geologic time unit, there needs to be "golden spike" that can be dug-up from the Earth (like fallout radionuclides or particulates from fossil fuel combustion) rendering the Anthropocene stratigraphically distinct from the Holocene and earlier epochs.  I imagine that before the full geologic society votes to create the Anthropocene one of the many possible stratigrahic layers deposited between 1945 & 1964 will be selected and the year in which that layer was deposited will be the starting point for the Anthropocene.

Best,
ASLR

Scientists are slowing converging to sometime between 1952 and 1955 in their attempts to define a 'Golden Spike':

Title: "Scientists home in on a potential Anthropocene 'Golden Spike'"

https://www.sciencedaily.com/releases/2018/01/180115095158.htm

Extract: "A new study suggests that key geological markers align towards a start for the Anthropocene somewhere between 1952 to 1955, based on signals from nuclear testing and fossil fuel burning.

Scientists within the Anthropocene Working Group are working towards developing a proposal, based upon finding a 'golden spike', more technically known as a Global Boundary Stratotype Section and Point (GSSP).

This is a reference level within recent strata somewhere in the world that will be proposed to most clearly and consistently characterise the changes as the Holocene, which represents the last 11,700 years of geological time on this planet, gave way into the Anthropocene about 65 years ago.

Once this detailed work is completed in a few years' time -- a required part of the process in seeking formalisation of the term by a number of geological bodies -- it will first be submitted for scrutiny to the Subcommission on Quaternary Stratigraphy of the International Commission on Stratigraphy. There is no guarantee, though, that the proposal will be accepted."
Title: Re: Early Anthropocene
Post by: AbruptSLR on October 15, 2018, 10:20:30 PM
Move evidence that Ruddiman (2003) roughly knew what he was talking about:

Title: "Pre-industrial anthropogenic CO2 emissions: How large?"

http://www.realclimate.org/index.php/archives/2018/10/pre-industrial-anthropogenic-co2-emissions-how-large/

Extract: "Fifteen years after publication of Ruddiman (2003), the early anthropogenic hypothesis is still debated, with relevant evidence from many disciplines continuing to emerge. Recent findings summarized here lend support to the claim that greenhouse-gas emissions from early agriculture (before 1850) were large enough to alter atmospheric composition and global climate substantially."
Title: Re: Early Anthropocene
Post by: Forest Dweller on October 21, 2018, 12:22:12 PM
This is a great topic, that i somehow managed to miss so far.
I personally like to see a scientist such as Ruddiman present their own work so here is a link for that:
https://www.youtube.com/watch?v=hqoh1jTBCh4&t=727s
Convincing to say the least.

I'd be cautious drawing any conclusions concerning our anthropological background.
We're barely scratching the surface yet it seems, dates and theories are adjusted all the time therefore.
Just a few surprising discoveries from the past year alone:

- Sapiens not 200,000 years old but 300,000 at Jebl Irhoud, Morocco
  (notice the location is also completely unexpected)

- Neanderthal man began the famous cave art in Europe, not our species. 60,000 + years dated.

- Neanderthal man did not just have sex with us, but also with the Denisovans:
  http://siberiantimes.com/science/profile/features/peek-inside-the-siberian-cave-where-inter-species-love-child-denny-lived-90000-years-ago/

More and more the picture emerges that well...everybody had sex with anybody.
It would not surprise me to see a discovery being made that concludes the same for H. Erectus or others.
Dmanisi, Georgia finds are very interesting in that context as well.
They don't fit anything well at all and even differ greatly from each other, yet are found together.
Sex is a pretty big thing after all, or to put it more in biological terms, reproduction is probably the primary driving force in nature.
Where there is a possibility, inter-species reproduction can be seen occurring today in cases such as the coywolf or the "grolar" for example.(grizzly x polar bear)
I'm pretty sure that if i were stuck on an island with a nice Neanderthal or Denisovan girl there would be some hanky panky going on... ;D

I do tend to agree about the terminology of the anthropocene being roughly equated to the holocene.
It is not unusual to divide these periods up so perhaps we should speak of "early anthropocene", "middle/late anthropocene" and so on.

The post WW2 spike is indeed interesting as well and i have a very simple explanation for myself about that.
As industrial activity ramps up in the 20th century it's first kept busy by 2 enormous(and horrendous) world wars.
Then the atomic bomb is used for the 1st time scaring the living crap out of everybody...war takes a step back.
This is when industrial focus shifts to our daily lives, this is when we all start getting our cars, tv sets, motorized lawnmowers, washing machines and so on.
A huge impact among a growing population results...the late anthropocene perhaps?
Title: Re: Early Anthropocene
Post by: Forest Dweller on October 21, 2018, 01:28:33 PM
Concerning the Americas i find it entirely plausible there was earlier human presence than that of acknowledged Siberian origins leading up to Clovis culture.
There's a few theories out there, the well known Polynesian theory of course, genetic matches between Japan and Chile, even a poorly based theory of aboriginal people from Australia reaching South America 40,000 years ago.

It's worth noting that in South America especially, traces of occupation disappear very quickly.
Percy Fawcett the famous explorer was looking for cities in the jungle carved from stone which is of course not present over there.
Thus, only recently have we surmised that pre-columbian culture was not so much nomadic hunter-gathering but actually an enormous sedentary agricultural society as well including roads and water management.
Their "cities" were just not like our centralized versions of them with agriculture around them but rather a network incorporating both everywhere.
The Amazon is not the virgin wild forest we tend to think it is, but also shaped by man.

Most interesting for early occupation of America is the Solutrean hypothesis as presented by Dennis Stanford.
I do believe there is some contradictory DNA evidence but it fails to explain some of the dates going back to 18-20,000 years, and the lithic evidence which is very striking indeed...you be the judge:
https://www.youtube.com/watch?v=VkrbIc-OMtE&list=PL6NU1Ai2Hnmqacx7LCfgqNOMDlkMDxNiz

The "megafauna extinction" by immigration of early hunter-gatherers, as pointed out in Terry's post indeed seems very flawed.
There is a similar one for Australia which seems to match chronologically but has little else going for it as well.
In America, we're talking a handful of primitive people wiping out 37 species, predators and prey, species of no interest whatsoever to humans.
Highly unlikely and not, as often thought happening overnight but over thousands of years.
The other main argument against this theory being of course, that if arrival of a few primitive people could have such massive effect then why is this not the case everywhere?
Why are there elephants, hippo's and lions in Africa when it is the cradle of mankind?

Title: Re: Early Anthropocene
Post by: Sebastian Jones on October 21, 2018, 06:03:08 PM


The "megafauna extinction" by immigration of early hunter-gatherers, as pointed out in Terry's post indeed seems very flawed.
There is a similar one for Australia which seems to match chronologically but has little else going for it as well.
In America, we're talking a handful of primitive people wiping out 37 species, predators and prey, species of no interest whatsoever to humans.
Highly unlikely and not, as often thought happening overnight but over thousands of years.
The other main argument against this theory being of course, that if arrival of a few primitive people could have such massive effect then why is this not the case everywhere?
Why are there elephants, hippo's and lions in Africa when it is the cradle of mankind?

I hesitate to wade into this topic, as, for some reason, folks get really worked up over it. Probably because it speaks to something fundamentally unsavoury about our species and poses serious issues about how we can achieve true sustainability.
But, well, here goes.
While we may never have real time video of early humanity causing mass extinctions whenever they arrive in a new place, it beggars belief that EVERY TIME a new land is colonized, the indigenous mega fauna is decimated.
Forest Dweller characterizes early Americans as primitive. In actual fact, early Americans were no more primitive than all of us on this forum.
Also, a very small amount of ecosystems science education shows us that the animals that are characterized as being of little interest to humans are dependent on an ecosystem disrupted by the removal of the easy prey.
And, finally to answer the question about why mega fauna persisted (until modern times) in Africa and South Asia- that is where humanity evolved, and so the animals were able to learn coping strategies over hundreds of thousands of years.
I could bang on but I shan't!
For a deeper yet accessible examination one could do a lot worse than read "The Call of Distant Mammoths " by Professor Peter D. Ward, University of Washington.
ISBN 0-387-98572-7
Title: Re: Early Anthropocene
Post by: wili on October 21, 2018, 06:09:09 PM
Try: "Why large, fierce animals are rare" (outside of Africa)

https://press.princeton.edu/titles/11307.html

Basically, large, fierce animals co-evolved with humans in Africa, and grew to instinctually fear and avoid them. Large animals elsewhere did not have sufficient evolutionary time to adapt to the new 'exotic invasive' that was humans.

I'm not saying that there aren't reasons for questioning the theory of humans as the/a cause for these extinctions, but just saying 'why weren't African large animals wiped out' doesn't necessarily by itself disprove the theory.

(Ah, I see Sebas answered the same time I did, and more eloquently and with a more recent source... Thanks.)
Title: Re: Early Anthropocene
Post by: kassy on October 22, 2018, 01:22:24 AM
There are also other local reasons involved.

In drier places you are more likely to run into each other around the water places. This was a factor in North America (and i guess Australia). No link just a recollection from some youtubed lecture. 

Europe is pretty crowded so our large fierce animals are long gone.

Africa is big and it had many not overly exploited habitats for a long time.

One possible nice example of animals co-evolving is the hippo. They charge humans at slightly over the length a human can effectively throw a hunting spear (according to the spear people/anthropologists but it makes sense).
Title: Re: Early Anthropocene
Post by: Human Habitat Index on October 22, 2018, 02:18:37 AM
Eternal Arms Race | Bats and Moths

https://www.youtube.com/watch?v=irkYP8vxVzE&feature=youtu.be
Title: Re: Early Anthropocene
Post by: Forest Dweller on October 25, 2018, 04:32:12 PM


The "megafauna extinction" by immigration of early hunter-gatherers, as pointed out in Terry's post indeed seems very flawed.
There is a similar one for Australia which seems to match chronologically but has little else going for it as well.
In America, we're talking a handful of primitive people wiping out 37 species, predators and prey, species of no interest whatsoever to humans.
Highly unlikely and not, as often thought happening overnight but over thousands of years.
The other main argument against this theory being of course, that if arrival of a few primitive people could have such massive effect then why is this not the case everywhere?
Why are there elephants, hippo's and lions in Africa when it is the cradle of mankind?

I hesitate to wade into this topic, as, for some reason, folks get really worked up over it. Probably because it speaks to something fundamentally unsavoury about our species and poses serious issues about how we can achieve true sustainability.
But, well, here goes.
While we may never have real time video of early humanity causing mass extinctions whenever they arrive in a new place, it beggars belief that EVERY TIME a new land is colonized, the indigenous mega fauna is decimated.
Forest Dweller characterizes early Americans as primitive. In actual fact, early Americans were no more primitive than all of us on this forum.
Also, a very small amount of ecosystems science education shows us that the animals that are characterized as being of little interest to humans are dependent on an ecosystem disrupted by the removal of the easy prey.
And, finally to answer the question about why mega fauna persisted (until modern times) in Africa and South Asia- that is where humanity evolved, and so the animals were able to learn coping strategies over hundreds of thousands of years.
I could bang on but I shan't!
For a deeper yet accessible examination one could do a lot worse than read "The Call of Distant Mammoths " by Professor Peter D. Ward, University of Washington.
ISBN 0-387-98572-7

Sebastian, i wasn't necessarily characterizing the 1st Americans as primitive beings, it's just the general term people use for those hunter-gatherers and i agree they were far from it.

Looking at some of the other recent comments;
I also did not say it is a good argument how megafauna in current Africa disproves the American megafauna diaspearance by humans.
I just said it is the main argument being used, not necessarily mine.
Some of the comments are really good, mentioning water sources, co-evolution versus new arrival of humans, regional differences and so on.

And you are correct Sebastian, why does this topic get people so worked up often?
Your suggestion about the implications concerning our species and sustainability is the best i can think of too, although it's not exactly like we feel very close to those early ancestors.
Maybe we just also like to think our modern "civilized" people are doing better, smarter...bit of vanity involved?

Safe to say, that either side of the discussion about human megafauna extinction requires a lot more evidence...video would be nice yes haha! ;D
Of course we haven't even mentioned any scenario with several contributing factors, including arrival of humans or not....
The best argument against the human caused extinction(as the only or decisive reason) to my mind would actually be how small human population was at the time, and the involved time span of the extinction.
2nd best argument would be the variety of species gone as i mentioned.
And sure, i understand cascading effects can affect species not of interest to humans too but that is still a lot of species.

Anyway, thanks all for your input.
The less we know, the more interesting it gets....
Full breakdown by our friends at Wikipedia here: https://en.wikipedia.org/wiki/Quaternary_extinction_event
Title: Re: Early Anthropocene
Post by: vox_mundi on October 28, 2018, 09:16:45 PM
A divertimento on why our species is not long for this earth ...

Anthropocene: Why the Chair Should Be the Symbol for Our Sedentary Age (https://phys.org/news/2018-10-anthropocene-chair-sedentary-age.html)

Quote
Why are there no chairs in the Bible, or in all 30,000 lines of Homer? Neither are there any in Shakespeare's Hamlet – written in 1599. But by the middle of the 19th century, it is a completely different story. Charles Dickens's Bleak House suddenly has 187 of them. What changed? With sitting being called "the new smoking", we all know that spending too much time in chairs is bad for us. Not only are they unhealthy, but like air pollution, they are becoming almost impossible for modern humans to avoid.

... If I was asked to make even a conservative estimate of the number of chairs in the world, I'd find it hard to go lower than 8-10 per person. Applying that logic, there could be more than 60 billion of them on the planet. Surely chairs should be one of the universal signals of the arrival of the Anthropocene? Just like the data required to justify the change in the name of our geological epoch, they are to be found on every continent.

For centuries before, chairs had persistently been associated with power, wealth and high status. They were about as widely used by the peasantry as a crown. The idea of chairs as a symbol of status still persists today. The highest attainment in my own profession, academia, is called "a chair". The individual that runs a meeting is called "a chair". The head of a company is also a chairman or woman. And it is a truth, universally acknowledged, that the best chair in any office building always belongs to the boss.

They are so necessary to leading a modern life that most of what we do seems unimaginable without them. Research conducted by the British Heart Foundation suggests that we enjoy about 9.5 hours per day of sedentary time. This means that modern humans are inactive for about 75% of their time.

Our bodies do their best to be the kinds of body that we need. Wolff's Law (https://en.wikipedia.org/wiki/Wolff%27s_law) and Davis's Law (https://en.wikipedia.org/wiki/Davis%27s_law) can be boiled down to the adage "use it or lose it" for the body's hard and soft tissues respectively. In both cases they tell us that muscle or bone will respond either to increased load or the cessation of use. Bones become thinner or denser. Muscles, stronger or weaker. Seated so much, with most of the musculature in our backs disengaged as they recline in a chair, it is little wonder that with our weakened spines, back pain is now the number one cause of disability, globally.

Just as we have an Anthropocene environment, we might equally class ourselves as Anthropocene humans. Palaeolithic humans died most frequently in infancy. Violence and injury were also common causes of mortality in later life. Modern humans, though, overwhelmingly die as a result of metabolic disorders such as type 2 diabetes, heart disease and some cancers – all strongly linked with inactivity: namely, chair use.

Arise!

(https://www.cyfe.com/blog/wp-content/uploads/2017/12/evolution.jpg)
Title: Re: Early Anthropocene
Post by: oren on October 29, 2018, 02:32:59 AM
Quote
Why are there no chairs in the Bible
Seriously?
I always wonder why someone which seems smart would start a write-off with a completely bogus claim, so easily falsifiable. Just google "chair in the bible"...
There are chairs (and thrones) - both in English and Hebrew versions of the bible, so it's not a translation issue either.
Title: Re: Early Anthropocene
Post by: vox_mundi on October 29, 2018, 04:12:53 AM
Lighten up oren

It was a divertimento: def: (n) a light and entertaining composition.

It was Vybarr Cregan-Reid's thesis according to the book review of his/her book 'Primate Change', quoted from the link I posted from phys.org. see https://phys.org/news/2018-10-anthropocene-chair-sedentary-age.html

 It's a different way of saying we spend to much time on our butt, a signature of our modern era.

Though, the fact that there are 7 billion more asses than we had a couple thousand years ago might have something to do with it.

I didn't take it as the last word in peer-reviewed analysis of seats and sitting. It's not going to matter a million years from now.
Title: Re: Early Anthropocene
Post by: oren on October 29, 2018, 10:18:35 AM
Honestly I don't mind, and we do spend too much time on our butt. But I'd expect at least the first sentence in an article on phys.org to be fact-checked.
Title: Re: Early Anthropocene
Post by: Gray-Wolf on October 29, 2018, 12:28:49 PM
I believe we find changes to the ankle bones of our prehistoric ancestors where constant 'squatting' altered to bones?

Folk on the move ( hunter gatherers ) would not be carrying chairs with them but would have sticks ( spears ) so squatting with the aid of that 'third leg' would have been their choice of rest positions ( better than permafrost soggy land surface!).

As we know from our folding 'camping chairs' a few sticks and a hide would fashion a comfy seat for in their semi permanent homes but out on the plains a stick and a squat would do just fine!
Title: Re: Early Anthropocene
Post by: Archimid on October 29, 2018, 01:51:16 PM
Vox_Mundi posted an image going from lower primates to the "sitting primate". Has anyone seen that image extended beyond the primates all the way back to the last mass extinction? In such image the earliest ancestor would look a lot more like this:

(https://assets3.thrillist.com/v1/image/2336538/size/sk-2017_04_article_main_desktop.jpg)
Title: Re: Early Anthropocene
Post by: AbruptSLR on November 04, 2018, 08:30:55 PM
From the linked reference I focus on the possibility/probability that anthropogenic fires was a large source of the increase in atmospheric methane from 21 kya until the pre-industrial era (circa 1750):

Hopcroft, P, Valdes, P & Kaplan, J, 2018, ‘Bayesian analysis of the glacial-interglacial methane increase constrained by stable isotopes and Earth System modelling’. Geophysical Research Letters.

http://www.bristol.ac.uk/geography/people/paul-j-valdes/pub/148471653

Abstract: "The observed rise in atmospheric methane (CH4) from 375 ppbv during the Last Glacial Maximum (LGM: 21,000 years ago) to 680 ppbv during the late preindustrial era is not well understood. Atmospheric chemistry considerations implicate an increase in CH4 sources, but process‐based estimates fail to reproduce the required amplitude. CH4 stable isotopes provide complementary information that can help constrain the underlying causes of the increase. We combine Earth System model simulations of the late preindustrial and LGM CH4 cycles, including process‐based estimates of the isotopic discrimination of vegetation, in a box model of atmospheric CH4 and its isotopes. Using a Bayesian approach, we show how model‐based constraints and ice core observations may be combined in a consistent probabilistic framework. The resultant posterior distributions point to a strong reduction in wetland and other biogenic CH4 emissions during the LGM, with a modest increase in the geological source, or potentially natural or anthropogenic fires, accounting for the observed enrichment of δ13CH4."