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Author Topic: Early Anthropocene  (Read 45067 times)

oren

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Re: Early Anthropocene
« Reply #100 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.

Gray-Wolf

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Re: Early Anthropocene
« Reply #101 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!
KOYAANISQATSI

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

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Re: Early Anthropocene
« Reply #102 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:

I am an energy reservoir seemingly intent on lowering entropy for self preservation.

AbruptSLR

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Re: Early Anthropocene
« Reply #103 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."
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