Climate flickering ended last ice age

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Discussion Overview

The discussion centers on the Younger Dryas event, a period of rapid climate change approximately 12,900 years ago, exploring its mechanisms, implications, and the nature of climate fluctuations leading to the end of the last ice age. Participants examine various hypotheses and evidence related to atmospheric and oceanic circulation changes, as well as potential external influences such as comet encounters.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants highlight the lack of consensus on the mechanisms behind the onset, stabilization, and termination of the Younger Dryas, referencing both proxy data and model simulations.
  • One participant questions the applicability of findings from local evidence in Norway to explain phenomena observed in distant locations like the Santa Barbara Basin and Caracio Basin.
  • Another participant proposes a hypothesis involving a near-miss comet encounter affecting Earth's axial tilt and climate oscillations, suggesting it aligns with observed climatic patterns.
  • Concerns are raised about discrepancies in the timing of climate transitions, specifically regarding varve counts related to the Younger Dryas and associated geological events.
  • Some participants express skepticism about speculative claims without peer-reviewed support, while others acknowledge the speculative nature of certain ideas but remain interested in exploring explanations for climate fluctuations.
  • A participant expresses a sense of futility in seeking definitive truths about these historical climate events, suggesting that enlightenment may be elusive.
  • Evidence of a micrometeorite bombardment around 12.9 ka is mentioned as a potential factor in the fluctuating climate, although its implications remain debated.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the mechanisms behind the Younger Dryas or the validity of speculative claims. Multiple competing views and uncertainties remain present throughout the discussion.

Contextual Notes

Participants note limitations in the current understanding of climate transitions, including the dependence on local evidence and unresolved discrepancies in geological timelines.

wolram
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http://www.sciencedaily.com/releases/2009/02/090216092824.htm

Quote.
The Younger Dryas event, which began approximately 12,900 years ago, was a period of rapid cooling in the Northern Hemisphere, driven by large-scale reorganizations of patterns of atmospheric and oceanic circulation. Environmental changes during this period have been documented by both proxy-based reconstructions from sediment archives and model simulations, but there is currently no consensus on the exact mechanisms of onset, stabilization, or termination of the Younger Dryas. In contrast to existing knowledge, the Nature article shows that the climate shifted repeatedly from cold and dry to wet and less cold, from decade to decade, before interglacial conditions were finally reached and the climate system became more stable.
 
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Yeah, great article Wolram.

Very interesting argument Andre. Very enlightening. Sorry to go on, but the 'large body close encounter' of a giant comet like near-miss with the Earth around 40,000 years ago we discussed earlier fits the bill. The tilt would have increased and then oscillated before settling into the Earth's obliquity cycle we are now familiar with. I'm surprised myself to see how it seems to fit all the criteria so effortlessly.
 
Does it with 30,000 years in between?

Moreover there is something fishy with that article. It suggests that the transition to the YD in the Meerfelder maar varves was around 12,870 varve count years ago. However here it is 12,700 years, which is quite robust, as being 200 varve years before the mega eruption of the Laacher see maar around 12,920 years ago.
 
Andre said:
Does it with 30,000 years in between?
It could take 30,000 years to reach it's maximum increase in obliquity, and then oscillate on a smaller scale until stabilization.
 
Mammo, overly speculative posts are not allowed here. Do you have any peer reviewed papers on such an incident? I have found nothing in my searches that even suggests such a thing.
 
I do seem to have got a bit carried away with myself Evo. I doubt whether there's a paper on the idea, I admit. I'm interested in other people's explanations of the fluctuations, it's a fascinating topic.
 
You guys will have to bicker amongst yourselves, i find there is is no truths in these things, may be we will never know, but i hope for enlightenment, but now i am fizzled out.
 
wolram said:
http://www.sciencedaily.com/releases/2009/02/090216092824.htm
The Younger Dryas event, which began approximately 12,900 years ago, was a period of rapid cooling in the Northern Hemisphere, driven by large-scale reorganizations of patterns of atmospheric and oceanic circulation.
The evidence of a micrometeorite bombardment (Firestone et al) around 12.9 ka is presumably a candidate for this fluctuating climate change.
 

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