Please support this Forum and Neven's Blog

Author Topic: Early Anthropocene  (Read 21827 times)

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #50 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
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

Juan C. García

  • ASIF Citizen
  • Posts: 372
    • View Profile
Re: Early Anthropocene
« Reply #51 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
Which is the best answer to Sep-2012 ASI lost?
50% [NSIDC extent vs 1979-2000] or
80% [Orig. PIOMAS volume vs 1979, 77.6% with corrections]

Volume is harder to measure than extent, but 3D is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC official trends underestimate the real speed of ASI lost.

ael

  • ASIF Lurker
  • Posts: 14
    • View Profile
Re: Early Anthropocene
« Reply #52 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.

LRC1962

  • ASIF Citizen
  • Posts: 398
    • View Profile
Re: Early Anthropocene
« Reply #53 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.
"All truth passes through three stages: First, it is ridiculed; Second,  it is violently opposed; and Third, it is accepted as self-evident."
       - Arthur Schopenhauer

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #54 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

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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #55 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

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


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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #56 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

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

sidd

  • ASIF Upper Class
  • Posts: 1096
    • View Profile
Re: Early Anthropocene
« Reply #57 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 ...

Laurent

  • ASIF Governor
  • Posts: 2517
    • View Profile
Re: Early Anthropocene
« Reply #58 on: March 22, 2016, 12:04:24 PM »
Rate of carbon emissions put in context
http://www.bbc.com/news/science-environment-35867438
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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #59 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

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

Laurent

  • ASIF Governor
  • Posts: 2517
    • View Profile
Re: Early Anthropocene
« Reply #60 on: April 04, 2016, 10:19:47 AM »
About absorbing non CO2 green house gazes :
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.

Laurent

  • ASIF Governor
  • Posts: 2517
    • View Profile
Re: Early Anthropocene
« Reply #61 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

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.

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #62 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

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

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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #63 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

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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #64 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

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

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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #65 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

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

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #66 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


Edit: W.R.T. Megafauna extinctions see Replies: #21, 24, 25, 37, 38, 62 & 63,
« Last Edit: October 19, 2016, 01:10:49 PM by AbruptSLR »
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

budmantis

  • ASIF Upper Class
  • Posts: 1072
  • "Be the change you wish to see in this world." MG
    • View Profile
Re: Early Anthropocene
« Reply #67 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.
"To predict the behavior of ordinary people in advance, you only have to assume that they will always try to escape a disagreeable situation with the smallest possible expenditure of intelligence." Nietzsche

AbruptSLR

  • ASIF Emperor
  • Posts: 11175
    • View Profile
Re: Early Anthropocene
« Reply #68 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


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

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

jai mitchell

  • ASIF Upper Class
  • Posts: 1490
    • View Profile
Re: Early Anthropocene
« Reply #69 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

some images follow







Haiku of Past Futures
My "burning embers"
are not tri-color bar graphs
+3C today