What is the status of the Early Anthropocene hypothesis, in the specific meaning that the climate would be projected to be significantly cooler (such as, on the order of by 0.8 degrees in the planet average) in a year corresponding to, say, 1800, if there was no agricultural revolution and no significant impact of our species on the climate starting several thousand years before that?

This is a layman's question. I'm familiar with Ruddiman's work and some of its early criticisms, but I'm unsure what the current generation of scientists thinks about the issue and if there's any strong recent evidence either way which I should read about.

Please don't focus too much on my use of the terms "anthropocene" or "glaciation" themselves in this question, but feel free to suggest better ways to refer to the above hypothesis or its current successors.

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    $\begingroup$ Can you please suggest a reference to Ruddiman's work? $\endgroup$ – Camilo Rada Jan 31 '18 at 14:27
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    $\begingroup$ Primarily this. But most of follow-up articles I can find about the topic on the web seem to be associated with Ruddiman somehow as well, which makes me wonder. $\endgroup$ – Jirka Hanika Jan 31 '18 at 17:11
  • $\begingroup$ I have read your reference and it is an interesting hypothesis. However I don't feel like giving an answer because I'm not sufficiently informed in that topic. I will only say that some theories are extremely difficult to prove or reject. In this case it is very difficult to quantify the impact of early humans with available information. Also, the book was based mostly in the Vostok ice core, and I know newer cores from other locations have allowed to provide a better picture of global parameters, and the current one have changed a significan amount from what was deduced from Vostok alone. $\endgroup$ – Camilo Rada Feb 1 '18 at 0:47

Our interglacial ends some 1500-years from now, the AGU recently recognized the Holocene as geo-engineered by people converting forest to agriculture.

We passed a warm-ocean tipping point for northern hemispheric winters, frozen oranges in Florida and rain in Alaska now will be common.

Our emissions rate is far beyond natural systems, the rate of change coming out of the last ice-age was 1-ppm/180-years, we hit 3ppm/year in 2016, 540-times faster.

And, the max CO2 during the late Pleistocene was 305-ppm, we hit that in 1916 and added 100-ppm in 100-years.

This carbon bomb is acidifying the oceans 10-times faster than the worst land extinction in geologic history.

It's very unwise what we're doing.

  • $\begingroup$ Can you please provide a source or reference for what you say about "AGU recently recognized the Holocene as geo-engineered by people converting forest to agriculture". Cheers $\endgroup$ – Camilo Rada Feb 1 '18 at 5:51
  • $\begingroup$ Tried AGU, it was a GSA honorarium not AGU, stillvlooking for the original author from decades, related to deltas inundations, consider Bering Strait opened right at 12,000-ybp as context to deforestation not related to post-glacial feedbacks the thesis iirc. $\endgroup$ – Tom Mallard Feb 1 '18 at 6:13

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