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Earth 'shook off' ancient warming
- Thread starter Ivan Seeking
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Discussion Overview
The discussion centers on how Earth may have recovered from a significant episode of global warming during the time of the dinosaurs, particularly focusing on the role of methane clathrates and the carbon cycle. Participants explore various hypotheses and mechanisms related to this ancient warming event and its implications for current climate understanding.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
Main Points Raised
- Some participants note that a massive methane burst from decomposing clathrate occurred 55 million years ago, suggesting that the current understanding may not be new.
- There is speculation about the role of geographic changes and tectonic uplift in destabilizing clathrates, rather than solely attributing it to warming.
- One participant argues that if warming were to cause clathrate destabilization, it could lead to a thermal runaway effect, which raises questions about the validity of warming as a cause.
- Another participant highlights the process of calcium combining with CO2 to form calcium carbonate as a potential mechanism for reducing atmospheric CO2 levels.
- Concerns are raised about the implications of current climate models, particularly regarding the potential release of vast reserves of carbon from methane ice if global temperatures reach critical levels.
- There is mention of the wet greenhouse thermal runaway hypothesis for Venus, with acknowledgment of its weaknesses and the need for integration of various hypotheses.
Areas of Agreement / Disagreement
Participants express differing views on the mechanisms behind ancient warming and the role of clathrates, indicating that multiple competing perspectives remain unresolved. There is no consensus on the primary causes or implications of the discussed phenomena.
Contextual Notes
Some participants point out limitations in the current understanding of the carbon cycle and the complexities of clathrate properties, suggesting that further exploration and integration of hypotheses are necessary.
- #2
Andre
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Interesting, but what is new?
The same event, a massive methane burst from decomposing clathrate happened 55MY ago at the Paleocene - Eocene boundary.
Silicone rock weathering to limestone is well known as a part of the carbon cycle and as a regulating mechanism for atmospheric CO2
The role of warming is pure speculation and not logical. Instead, geographic changes could also account for destabilizing clathrate. Tectonic uplift could also release seawater pressure over large clathrate fields causing the instability
If warming was to cause the clathrate to decompose which causes more greenhouse effect warming, then more warming should decompose even more clathrate, causing even more warming, etc and a "thermal runaway" situation should emerge. this allegedly has happened to Venus too (but not really), hence this would suggest that warming could not be the cause of clathrate destabilisation.
Nowadays, however, it seems to be unthinkable to publish any geologic article and not relating it to global warming somehow.
The same event, a massive methane burst from decomposing clathrate happened 55MY ago at the Paleocene - Eocene boundary.
Silicone rock weathering to limestone is well known as a part of the carbon cycle and as a regulating mechanism for atmospheric CO2
The role of warming is pure speculation and not logical. Instead, geographic changes could also account for destabilizing clathrate. Tectonic uplift could also release seawater pressure over large clathrate fields causing the instability
If warming was to cause the clathrate to decompose which causes more greenhouse effect warming, then more warming should decompose even more clathrate, causing even more warming, etc and a "thermal runaway" situation should emerge. this allegedly has happened to Venus too (but not really), hence this would suggest that warming could not be the cause of clathrate destabilisation.
Nowadays, however, it seems to be unthinkable to publish any geologic article and not relating it to global warming somehow.
- #3
Evo
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From this quote from the story
Sounds like the Earth created it's own widescale version of TUMS to get rid of the gas.
- #4
Nereid
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Venus? not just a pretty girl
As Andre said, the carbon cycle is known and (fairly) well understood ... among the cognoscetti
. I'm being unfair, IIRC, it has been published in SciAm, and is discussed in Peter Ward's "Rare Earth". Evo's characterisation "Sounds like the Earth created its own widescale version of TUMS to get rid of the gas" is a wonderfully evocative summary (tho' if you don't live in the US, and don't know what "TUMS" is/are ...). 
The fly in the ointment is the fact that the Sun is brighter than it was 180 mya, so the distance to a runaway greenhouse is an awful lot closer ... not even notNewton or Bystander (or Russ) would like to live on Venus ... [b(]
As Andre said, the carbon cycle is known and (fairly) well understood ... among the cognoscetti
. I'm being unfair, IIRC, it has been published in SciAm, and is discussed in Peter Ward's "Rare Earth". Evo's characterisation "Sounds like the Earth created its own widescale version of TUMS to get rid of the gas" is a wonderfully evocative summary (tho' if you don't live in the US, and don't know what "TUMS" is/are ...). The fly in the ointment is the fact that the Sun is brighter than it was 180 mya, so the distance to a runaway greenhouse is an awful lot closer ... not even notNewton or Bystander (or Russ) would like to live on Venus ...
[b(]- #5
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"Dr Cohen added that there are still vast reserves of carbon - possibly as much as 14,000 gigatons - locked up as methane ice in ocean sediments.
If global temperatures reach a critical point, it is possible they might suddenly be released into the atmosphere causing a similar event to the one that occurred during the Jurassic. "
40kg/m2? Uh-uh. "... suddenly be released..." Uh-uh ---tain't Lake Nyos. Time for people to read the material on clathrates and their properties in, Water, a Comprehensive Treatise, Felix Franks.
If global temperatures reach a critical point, it is possible they might suddenly be released into the atmosphere causing a similar event to the one that occurred during the Jurassic. "
40kg/m2? Uh-uh. "... suddenly be released..." Uh-uh ---tain't Lake Nyos. Time for people to read the material on clathrates and their properties in, Water, a Comprehensive Treatise, Felix Franks.
- #6
Andre
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Nereid,
Your hints to the mysterous deitic planet suggest that you endorse the wet greenhouse thermal runaway hypothesis for Venus. You're probably also familiar with the hypothesis of the spinning stop of Venus due to atmospheric drag (Correia et al). However, both hypotheses have their weaknesses. One of them being a lack of integration.
Familiar with/interested in Andre's hypothesis of all Venus enigmatic features?
Posted it here about over half a year ago.
Your hints to the mysterous deitic planet suggest that you endorse the wet greenhouse thermal runaway hypothesis for Venus. You're probably also familiar with the hypothesis of the spinning stop of Venus due to atmospheric drag (Correia et al). However, both hypotheses have their weaknesses. One of them being a lack of integration.
Familiar with/interested in Andre's hypothesis of all Venus enigmatic features?
Posted it here about over half a year ago.
- #7
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As indicated:
https://www.physicsforums.com/showthread.php?s=&threadid=2974
https://www.physicsforums.com/showthread.php?s=&threadid=2974
- #8
Nereid
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Andre, I looked it over last year, and concluded it'd take me quite some time to come to grips with it sufficiently to post half-way decent questions and challenges. Then I got more interested in other things ... and never got back to it (maybe Nereid is a kind of butterfly?)
- #9
Andre
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Thanx Ivan Seeking for digging up that old thread.
https://www.physicsforums.com/showthread.php?s=&threadid=2974
I put in an overview of the general idea again. Obviously, this would be the wrong thread for it. Of course I like the idea to be understood and challenged, Nereid, to see if can survive a sanity check. For instance, I realize that conservation of momentum is a though discussion item.
https://www.physicsforums.com/showthread.php?s=&threadid=2974
I put in an overview of the general idea again. Obviously, this would be the wrong thread for it. Of course I like the idea to be understood and challenged, Nereid, to see if can survive a sanity check. For instance, I realize that conservation of momentum is a though discussion item.
- #10
Tsu
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Maybe we should give some to that whale of Ivans! Ivan! Where's the picture of that whale? Show us again!Originally posted by Evo
From this quote from the story Sounds like the Earth created it's own widescale version of TUMS to get rid of the gas.
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