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I have written to Professor Kennett of UCSB for a summary of the state of the knowledge on this topic. I also wrote to a NCAR researcher to find out if this hypothesis is modelled in the AOGCMs. Simesa 18:58, 18 May 2006 (UTC)
This article states the global warming potential of atmospheric methane as 23 over 100 years; the methane clathrate article states the same potential as 21 over 100 years. Which is more accurate? —Preceding unsigned comment added by 66.74.164.155 ( talk) 15:19, 21 November 2009 (UTC)
I was looking at both the page on Methane and this one and I noticed some dissimilar information on the effects of methane on the greenhouse gas effect. Most notably, the exact figures of the effect of methane. This page does not seem to have a citation for the figures, where as the methane page does. One of these instances cites the half life of methane at 12 years in the atmosphere where as the methane page has values of 9.6 years and 8.4 years, depending on the level of atmosphere. If the 12 year value is correct, could someone please document it? The methane pages also mentions the environmental impact with "Because of this difference in effect and time period, the global warming potential of methane over a 20 year time period is 72." This value is much different than the one on this page. —Preceding unsigned comment added by Spotowski ( talk • contribs) 22:26, 14 March 2009 (UTC)
In its original form, the hypothesis proposed that the "clathrate gun" could cause abrupt runaway warming (A) in a timescale less than a human lifetime, (B) [1] and might be responsible for warming events in and at the end of the last ice age (C). [2] This is now thought unlikely.[3][4]
Which is "now thought unlikely", A, B or C? 67.52.81.242 ( talk) 04:54, 14 November 2010 (UTC)
Let us put this way, we hope it won't happen and based on what we think us know today it will not be able to do it. But then there are those evidence that see an accelerating methane in the shallow seas of the arctic, combined with studies that recently questioned our beliefs of the time rate of earlier historical methane releases, instead of placing it between 400-1300 y now think it can happen in a century or two? Myself I expect a cocktail of effects accelerating all temperature raises, and there methane definitely will be included. And there's one thing more, until recently we thought that the main problem with bogs etc would be the methane, but 'experimenting', separating and partially drying a lake in Siberia, it was found that a considerable amount of CO2 will be contributed. http://news.softpedia.com/news/Warming-Tundra-Releases-Carbon-Dioxide-118363.shtml
And if you look at timescales CO2 have an expected tail of influence, at least a millennium long, which makes it our number one priority. As long as methane doesn't accelerate into a giant 'spike' we won't get a tipping from that alone, and its timescale of influence is decades instead of millenniums. But then there is that possible 'spike'? I don't know, I sincerely hope it never will come to that though as .. I'm sure you can figure out why I hope so yourself.
Look up "Methane release from the East Siberian Arctic Shelf. by Natalia Shakhova, Igor Semiletov."
Yoron. 178.30.89.241 ( talk) 23:15, 17 June 2011 (UTC)
now thought unlikely
IMO this statement should be removed. Both of the citations for the statement are from 2006. Meanwhile the article cites empirical data from 2008 (Shakhova et. al) that pretty much tells the opposite story. This scenario isn't unlikely as it is already happening at the estimated rate of 0.5 Mt/y! Why does the first intro phrase to "Current Outlook" still read modelling by Archer (2007) suggests the methane forcing should remain a minor component of the overall greenhouse effect.[17] when there is more recent empirical data suggesting something else? Does Archer's model predict the data gathered in 2008? If not it should not be mentioned in such a prominent place - a model that doesn't validate against the present is certainly not predicting the future. Is a climate scientist here to comment on this? I'm a software engineer working in this field (atmospheric simulations), but I don't feel qualified to do a full edit on this article, I just feel it has serious contradictions. If no-one steps forward I will do an attempt anyways however. Muellermichel ( talk) 15:04, 17 June 2016 (UTC)
The ambiguous statements attributed to Ryskin 2003 appear to be out of date, as does the lead section "however" attributed to BBC 2002. Viriditas ( talk) 10:39, 30 November 2012 (UTC)
Likewise regarding the statement that "the existence of vast oceanic methane clathrate formation is uncertain and usually only based on reflective seismology and pieces larger than 10 cm have only been recovered from three sites." The statement references a publication by Jean Laherrere from May, 2000, which was probably correct at the time. I'm pretty sure that in the 12+ years since then, the uncertainty has been substantially reduced. There have even been experimental drilling campaigns by the Japanese to test the feasibility of commercial development. I don't have a reference, offhand, and the article(s?) I recall didn't report a definitive yes / no as to commercial feasibility, but the drilling did achieve some level of production. Agnostic Engineer ( talk) 19:39, 7 January 2013 (UTC)
Princeton University issued a news release entitled: "On warmer Earth, most of Arctic may remove, not add, methane"; from the article: "new research led by Princeton University researchers and published in The ISME Journal in August suggests that, thanks to methane-hungry bacteria, the majority of Arctic soil might actually be able to absorb methane from the atmosphere rather than release it. Furthermore, that ability seems to become greater as temperatures rise.
The researchers found that Arctic soils containing low carbon content — which make up 87 percent of the soil in permafrost regions globally — not only remove methane from the atmosphere, but also become more efficient as temperatures increase. During a three-year period, a carbon-poor site on Axel Heiberg Island in Canada’s Arctic region consistently took up more methane as the ground temperature rose from 0 to 18 degrees Celsius (32 to 64.4 degrees Fahrenheit). The researchers project that should Arctic temperatures rise by 5 to 15 degrees Celsius over the next 100 years, the methane-absorbing capacity of “carbon-poor” soil could increase by five to 30 times.
The researchers found that this ability stems from an as-yet unknown species of bacteria in carbon-poor Arctic soil that consume methane in the atmosphere. The bacteria are related to a bacterial group known as Upland Soil Cluster Alpha, the dominant methane-consuming bacteria in carbon-poor Arctic soil. The bacteria the researchers studied remove the carbon from methane to produce methanol, a simple alcohol the bacteria process immediately. The carbon is used for growth or respiration, meaning that it either remains in bacterial cells or is released as carbon dioxide."
https://blogs.princeton.edu/research/2015/08/14/on-warmer-earth-most-of-arctic-may-remove-not-add-methane-isme-journal/ Frunobulax ( talk) 20:00, 17 August 2015 (UTC)
NASA recently finished a 5 year mission studying this and said the climate models need to change. 1 — Preceding unsigned comment added by LDWoodworth ( talk • contribs) 16:51, 27 July 2016 (UTC)
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This section needs an update based on new research through to 2018, they found that the clathrates are stable and the extra methane is seeping from rocks below them and has done so for thousands of years since the rise after the last ice age made the layer more permeable. This basically debunks the clathrate gun hypotheseis. I'll edit the article when I get time or someone else might like to do it. See Arctic methane emissions#Contribution to climate change Robert Walker ( talk) 03:16, 6 July 2018 (UTC)
"In addition to potential changes in the magnitude of in a warmer,increasingly ice-free Arctic Ocean (37), we must also consider that the rate of CH4 removal processes, such as aerobic CH4 oxidation by microorganisms in the water column (6,35), could also change. Thus, to accurately constrain the mobilization of ancient C and the subsequent emission of CH4, we recommend that natural abundance14C-CH4analyses should be conducted in future studies of CH4 dynamics."
You may also have noticed I updated the lede - which is now inconsistent with this section which is out of date and so needs more work: Clathrate gun hypothesis#Possible release events needs work. As you'll see from the USGS metastudy [2] and also the cites which I got from the Wikipedia here Permian–Triassic extinction event#Methane hydrate gasification then the clathrate hydrates no longer seem to be considered a viable hypothesis for the PETM.
Also Sparrow et al, 2018 look briefly at a more recent anaogue: [3]says
Although the global atmospheric CH4 inventory is increasing, arctic CH4 growth rates are comparable to or less than the global average (7) and appear to be derived mainly from biogenic sources (2, 8, 9). Ancient C stores, including arctic permafrost and hydrates, were recently determined to have contributed 19% of the CH4 released to the atmosphere during the Younger Dryas – Preboreal abrupt warming event (10), an analog to climate change today.
The paper they cite is here, Petrenko et al, 2017 [5] (ScienceDaily also covered this paper. [6])
"To the extent that the characteristics of the most recent deglaciation and the Younger Dryas–Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur."
We should also mention the IPCC review of methane clathrate research from 2017
"Clathrates: Some economic assessments continue to emphasise the potential damage from very strong and rapid methane hydrate release (Hope and Schaefer, 2016), although AR5 did not consider this likely. Recent measurements of methane fluxes from the Siberian Shelf Seas (Thornton et al., 2016) are much lower than those inferred previously (Shakhova et al., 2014). A range of other studies have suggested a much smaller influence of clathrate release on the Arctic atmosphere than had been suggested (Berchet et al., 2016; Myhre et al., 2016). New modelling work confirms (Kretschmer et al., 2015) that the Arctic is the region where methane release from clathrates is likely to be most important in the next century, but still estimates methane release to the water column to be negligible compared to anthropogenic releases to the atmosphere. A recent review (Ruppel and Kessler, 2017) emphasises that there remains little evidence that clathrate methane is reaching the atmosphere at present. Although methane that is oxidised in the water column will not reach the atmosphere, it will have the effect of further lowering the pH of the ocean (Boudreau et al., 2015). A recent modelling study joined earlier papers in assigning a relatively limited role to dissociation of methane hydrates as a climate feedback (Mestdagh et al., 2017). Methane concentrations are rising globally, raising interesting questions (see section on methane) about what the cause is (Nisbet et al., 2016; Rigby et al., 2017; Schaefer et al., 2016; Turner et al., 2017). finally new measurements of the 14C content of methane across the warming out of the last glacial period (Petrenko et al., 2017) show that the release of old carbon reservoirs (including methane hydrates) played only a small role in the methane concentration increase that occurred then"
Robert Walker ( talk) 21:55, 4 August 2018 (UTC)
Reductions in sea ice and other changes may affect the amount of carbon dioxide absorbed by the Arctic Ocean, while thawing permafrost is expected to increase emissions of methane. However, projections of future impacts on Arctic sources and sinks of greenhouse gases are still hampered by data and knowledge gaps.
Yes - and the thing that made the original CGH alarming is the size of the reservoir that could suddenly be released in the runaway feedback effect where the warming lead to more methane released. The other things such as the subsea and land permafrost can impact on global warming too, but in the articles I've read on the topic, projections so far are significantly smaller than the total global warming effects due to humans, so are more like details - adjusting the projections by a fraction of a degree or some such.
If there isn't enough of a reservoir then you can only have so much feedback effect, mainly just increased due to the global warming from CO2 rather than the methane itself. Also because methane is so short lived in the atmosphere, then even if you have a large reservoir, it still has to be released quickly as well to cause a runaway. With the clathrates there is a large enough reservoir but with the new research, as I understand, the consensus emerging is that it isn't released fast enough for a runaway. Just saying, maybe that needs to be explained to the reader in a little more detail to give it context. As for the subsea and land permafrost then though it's not due to clathrates, it is still relevant to the article I think, maybe it can have a section about whether there can be a runaway methane emission from other causes - and even also the idea of a runaway CO2 effect like Venus and explaining that there aren't enough fossil fuels even if they are all burnt for that to happen, there's the moist greenhouse effect to, which is outcome of a partial CO2 runaway not possible now but could happen a hundred million years in the future in one article I read - don't want to overwhelm the article, more like a short section on related ideas at the end, linking to other articles here on those topics, may be a good idea. I don't have time to read the cites right now, but hope to come back to it soon. Robert Walker ( talk) 13:56, 5 August 2018 (UTC)
Maybe titled something like "Other potential climate change runaway effects" and then briefly go into the other methane sources and how they aren't large enough for a runaway, or like the clathrates, are released too slowly for a runaway - and then the CO2 runaway hypothesis which briefly was thought to be theoretically possible if we burn all the fossil fuels, but soon disproved. Robert Walker ( talk) 14:08, 5 August 2018 (UTC)
That would also help with potential confusion of CH4 and CO2 runaways. Robert Walker ( talk) 14:09, 5 August 2018 (UTC)
All I can say about my topic ban is that broadly construed means that I am not permitted to comment on or even hint at anything to do with the topic or anything that lead to my indef topic ban on Buddhism. About the only thing I am permitted to say is that I am Buddhist, and if asked what that means I can't answer that either. Can I ask you kindly to not discuss it futher here with other editors, as I am not permitted to respond.
Please though decide for yourself whether I am doing a wall of text here, rather than rely on what others said about me in an unrelated discussion, in an unrelated topic area. I am involved in many other editing areas and with one other exception, which I can talk about, I have never been accused of walls of text in any other topic on Wikipedia, even when both myself and the other editor write multiple pages of content. This is because what I write is always directly relevant to improving the article. See for instance these long discussions on microtonal music with another editor with equally long responses and you can see how my responses are appreciated by them and vice versa Talk:Regular diatonic tuning#Meantone temperament. That is with the exception of Life on Mars and Planetary Protection. If you look further back then you will find discussions I can talk about related to the topic of habitability of present day Mars. There was a great fracas about that during which I was accused of walls of text and trolling, which you can find if you search back in my history - but do bear in mind - the final outcome after one of the opposing editors who was opposing my content on Wikipedia left for a six month sabbatical was that I wrote the articles Modern Mars habitability and Present day Mars habitability analogue environments on Earth which were so obviously good and well researched that nobody has suggested they should be deleted - they give an idea of the quality of my work on Wikipedia, even though I had had opposition for several years from an editor who prevented me from adding any material on these topics to the encyclopedia. They have only had minor edits by wikignomes - I am the sole author. And I wrote half of the article Planetary protection and nearly all of Interplanetary contamination after the fuss died down about my attempt to add extra material on these topics.
If we already have too much material to discuss, without going into this idea of an extra section for the article to help clarify the connection with other runaways and with CO2 feedback, then that's fine by me. It was just a suggestion. In case it wasn't clear I was responding to this part of what you said:
"What is misleading is bad writing (whether its here or somewhere else) that fails to explain issues related to greenhouse gases in something of a venn diagram fashion. As we all know here, methane is just one of the GHGs (but readers are confused about this). I can hear it now, "C4... isn't that carbon dioxide?" Once the reader undstands there are different compounds in natural sinks/sources, and the reader focuses on methane, there are many different processes to talk about."
This suggestion of an extra section, which I sketched out in my response, was an idea of how to help with that. But we can leave it for future discussion! Got plenty of other things to do :). Robert Walker ( talk) 15:27, 5 August 2018 (UTC)
On your second comment, yes I can work on those articles, if I have time. I haven't checked, I'd have thought they would cover these topics. Perhaps the suggestion wasn't clear? I didn't mean a new section going into that in detail. I meant a short section that just explains the basic idea of a runaway and why the clathrates are not a runaway if the emissions are small compared to other effects - and a one or two sentence mention of other methane sources and a brief explanation of why they are not considered to be capable of a runaway either (unless of course any are but I don't think they are) and of the CO2 runaway hypothesis and why that also is now discounted - the whole thing just one short para with interwiki links to find out more. I think this would add to clarity of this article. Robert Walker ( talk) 15:39, 5 August 2018 (UTC)
"Short-term temperature warming has limited impact on the gas hydrate stability. We show that warming can significantly affect gas hydrates in the seabed only when ocean temperature is constantly rising for several centuries,"
"The increase of methane flux started several hundreds to thousands of years ago, which is well before any onset of warming in the Arctic Ocean that others have speculated,"
Hope you don't mind - easier to read if not indented too far.
I see you have made many other changes throughout the article including a major rewrite of the lede, generally in the direction of making the clathrate gun hypothesis seem more plausible as an ongoing still viable theory. I don't have time to discuss such major chagnes right now.
I know what it can be like on Wikipedia with these discussions and I don't have enough time on my hands to go through this and especially not in an area where I have been advised there are discretionary sanctions, which means that emotions run high, and can even mean that someone might unexpectedly take you to WP:ANI mid conversation unexpectedly, and that I most definitely do not have time for. I mean not suggesting you would, but someone might, if feelings run high..
I thought I was just doing simple fixing of an article that was a bit out of date, and didn't include the latest research. This is the type of work I prefer in Wikipedia and I have no stomach for controversial areas, nowadays, especially not after various bad past experiences here.
But if I can make a couple of suggestions, I think the lede should cite the USGS and IPCC surveys if you are going to cite that 2018 one, especially because they are not behind paywalls and are highly regarded too. We cite articles that the readers can check for themselves where possible and as they are from 2017 they are hardly out of date.
And I don't know why you removed the material from the lede about how scientists used to think the PETM warming was due to clathrates decomposition and that this was later disproved. Indeed you have dealt with this matter of the "Possible release events" section by just deleting the entire section, and all mention of connection with past events. I think it is of great interest to the reader to know that this hypothesis has been disproved. Because it casts significant doubt on whether it could happen today if it didn't happen in the PETM or in the Lower Dryas temperature excursion. Meanwhile in articles and blog posts off wiki they will read that it happened in the PETM and will come here assuming that and will read an article that does not disabuse them of this now out of date idea..
Normally when editors plan such substantial changes to an article then they discuss it on the tal pages first. I did that before my edits. The only reason I went ahead and edited it was because no-one replied. Then when nobody responded to my edits either - I went on and continued to edit it as an apparently dormant article that nobody was much interested in. If I had thought there was interest from other editors I'd have discussed it all here first. It was because nobody responded so I did as is advised to "be bold" and do the edit anyway.
I never do substantial or possibly controversial edits before discussing them on the talk page first. Not in all the time I've been on Wikipedia. That is just not how I do things. For instance with the habitability of Mars and the Planetary protection issues, I discussed all my edits on talk pages first, went ahead and did them, worked on them for some months - and they were there for some time before someone came along and decided to remove the material from wikipedia. When that happened I then tried to resolve the issue on the talk pages. That is how I operate.
Especially here - there's the risk of emotions running high, of someone deciding to take you to WP:ANI, and also, that when an article is so much in flux then in my experience probably this means it is going to flip flop between different versions of the text and be edited and re-edited for possibly a long time - and I haven't the time to work through that right now.
But I have found this discussion so far rather useful, and I hope you have too. I might write my own article based on all this off wiki, on Quora or my science blog, to help clarify ideas and then maybe can come back here at a later date once the ideas are clearer here and see if I can help with whatever form it is in by then. Just not now when it is in such flux.
But good luck with the article and I hope you get some clarity here! I may come back a bit later and see what has happened. Robert Walker ( talk) 04:40, 6 August 2018 (UTC)
Oh my apologies! Not to excuse it but for understanding - it's maybe partly because of previous bad experiences here on Wikipedia. I over-reacted. I see that your edit was mainly moving things about rather than removing them. The sections that I thought were just gone were moved somewhere else.
It is clearly mid edit and you may have more changes you want to do and the USGS cite especially is vast - no way I have time to read it in detail at the present, just read some sections especially relevant to the clathrate gun hypothesis and their overview "press release" style page. I expect probably you haven't either yet, just because it is so long, and a very technical paper, and a new cite here. I strongly recommend reading it. Seems to be the best most authoritative work there is out there on this topic and essential background reading. And the other articles are also rather technical and most can probably do with a re-read. It is easy to make mistakes - even Phys.org did when they wrote 1.8 C instead of -1.8 C and they are generaly a reasonable WP;RS. Just a mistake on their part and we can make mistakes too.
I think though that I should leave further comment until whatever time you feel you have read the cites we've been discussing, integrated them into you rewrite, and feel happy with the article. Then do post here and say your rewrite is done. Then I can comment on it. I am very happy to let someone else do the work of the rewrite, so long as it is part of a conversation and we are working on the article together rather than just taken into their heads to do a major rewrite without discussing it first, as happens here on Wikipedia sometimes - I first encountered that with the Mars / Habitability where one editor just went around Wikipedia removing all the content in all the articles anything to do with planetary protection, and another editor removed all material anything to do with the present day habitability of Mars. The motivation is a little unclear but the one removing the planetary protection article was quite specific he said he was sick of seeing sections in the articles on concerns about forward contamination of Mars by microbes brought there by human colonists. So he had a pro-colonization political motivation for removing this material. Eventually he deleted nearly all of the main planetary protection article. It was quite shocking, for a weeks Wikipedia had almost no material on this topic. Since then I have been able to restore just about all the material that was deleted and in much improved form too with many cites. Anyway I was a bit worried you were acting like him, sorry!
Thanks! Robert Walker ( talk) 05:36, 6 August 2018 (UTC)
Recent observations of extensive methane release from the seafloor into the ocean and atmosphere cause concern as to whether increasing air temperatures across the Arctic are causing rapid melting of natural methane hydrates. Other studies, however, indicate that methane flares released in the Arctic today were created by processes that began way back in time – during the last Ice Age.
Newest research from the Center for Arctic Gas Hydrate, Climate and Environment (CAGE) shows that methane has been leaking in the Arctic for millions of years, independent of warm or cold climate. Methane has been forming in organic carbon rich sediments below the leakage spots off the coast of western Svalbard for a period of about 6 million years (since the late Miocene). According to our models, methane flares occurred at the seafloor for the first time at around 2 million years ago; at the exact time when ice sheets started to expand in the Arctic.
The acceleration of leakage occurred when the ice sheets were big enough to erode and deliver huge amounts of sediments towards the continental slope. Methane leakage was promoted due to formation of natural gas in organic-rich sediments under heavy loads of glacial sediments. Faults and fractures opened within the Earth’s crust as a consequence of growth and decay of the massive ice masses. This brought up the gases from deeper sediments higher up towards the seafloor. These gases then fueled the gas hydrate system off the Svalbard coast for the past 2 million years. It is, to this day, controlling the leakage of methane from the seabed.
Just to make it clear, as you didn't respond, do say when your revision is complete, @ Prokaryote:. Because I made a number of specific criticisms in our last conversation that have not been addressed. Rather than dive in and edit it and possibly end up in an edit war, I think it has to be discussed on the talk page first.
Once it is finished do let me know and I will do a bulleted list of the main things I think need to be fixed, or at least, discussed, and then we can come to some kind of resolution and mutual agreement / understanding on what the reliable sources are saying. Or if there are differences in views in the literature, then to make sure all the views are expressed in the article. In several key points I think the current article doesn't express what the literature says quite yet.
I will read the USGS overview article first and re-read some of the cites here before commenting on your final version of the article. I'm going to do that anyway when I find time. Do take your time, and spend as much time as you need on your rewrite, but I'd like to know when it is finished. Thanks! Robert Walker ( talk) 10:40, 7 August 2018 (UTC)
"Clathrates: Some economic assessments continue to emphasise the potential damage from very strong and rapid methane hydrate release, although AR5 did not consider this likely. Recent measurements of methane fluxes from the Siberian Shelf Seas are much lower than those inferred previously. A range of other studies have suggested a much smaller influence of clathrate release on the Arctic atmosphere than had been suggested.
…. A recent modelling study joined earlier papers in assigning a relatively limited role to dissociation of methane hydrates as a climate feedback. Methane concentrations are rising globally, raising interesting questions (see section on methane) about what the cause is, finally new measurements of the 14C content of methane across the warming out of the last glacial period show that the release of old carbon reservoirs (including methane hydrates) played only a small role in the methane concentration increase that occurred then."
"Our analysis of sediment cores of Western Svalbard unambiguously confirms that retreat of the Barents Sea ice sheet led to offshore gas hydrate dissociation, a process that has been widely speculated upon from modeling and geological observations3, 5, 38,39,40,41 but up until now, has remained unproven. Furthermore, combined modeling and geochemical analysis reveals that methane hydrates at the up-dip limit of the hydrate stability zone decomposed via postglacial isostatic rebound in contrast to previous hypotheses that invoke anthropogenic bottom water warming7, 9. Our data and model results also show that gas hydrates are not in themselves a significant source for gas release at the seabed. Rather, they act as a dynamic seal that blocks fluid-flow pathways for gas migration from deep geological reservoirs."
Robert Walker ( talk) 14:22, 7 August 2018 (UTC)
See WP:LEADSECTION. The lead must be a summary of the body of the article. If it isn't in the body of the article, it shouldn't be in the lead. In practice, there are frequent exceptions for short and stub articles, but this is neither. NewsAndEventsGuy ( talk) 15:23, 8 August 2018 (UTC)
I'll review and edit as there is time and interest, about all I can say. Follow Wiki rules and do as you will. NewsAndEventsGuy ( talk) 16:16, 8 August 2018 (UTC)
References
In this article introduction, it states:
A 2018 published review concluded that the clathrate gun hypothesis remains controversial, but that better understanding is vital. [1]
So I opened the article to see in what point it is controversial, and it states:
In addition to responses of wetland CH4 fluxes to changes in temperature and precipitation, natural CH4 sources such as permafrost soils, lakes, and coastal regions may have all played significant roles in determining the preindustrial CH4 concentration (19). Indeed, loss of large amounts of CH4 from marine clathrate deposits in response to warming (the clathrate gun hypothesis) has in the past been suggested as the primary cause of increases in atmospheric CH4 concentrations during the Quaternary (20). Although the clathrate gun hypothesis remains controversial [2], a good understanding of how environmental change affects natural CH4 sources is vital in terms of robustly projecting future fluxes under a changing climate.
— Reay, Dave S.; Smith, Pete; Christensen, Torben R.; James, Rachael H.; Clark, Harry (2018). "Methane and Global Environmental Change". Annual Review of Environment and Resources. 43: 165–192. doi: 10.1146/annurev-environ-102017-030154.
So, let's see what the source of this claim says:
Abstract: It has been suggested that the release of clathrates rather than expansion of wetlands is the primary cause of the rapid increases observed in the ice-core atmospheric methane record during the Pleistocene. Because submarine sediment failures can involve as much as 5000 Gt of sediment and have the capacity to release vast quantities of methane hydrates, one of the major tests of the clathrate gun hypothesis is determining whether the periods of enhanced continental-slope failure and atmospheric methane correlate. To test the clathrate gun hypothesis, we have collated published dates for submarine sediment failures in the North Atlantic sector and correlated them with climatic change for the past 45 k.y. More than 70% by volume of continental-slope failures during the past 45 k.y. was displaced in two periods, between 15 and 13 ka and between 11 and 8 ka. Both these intervals correlate with rising sea level and peaks in the methane record during the Bølling-Ållerød and Preboreal periods. These data support the clathrate gun hypothesis for glacial-interglacial transitions. The data do not, however, support the clathrate gun hypothesis for glacial millennial-scale climate cycles, because the occurrence of sediment failures correlates with Heinrich events, i.e., lows in sea level and atmospheric methane. A secondary use of this data set is the insight into the possible cause of continental-slope failures. Glacial-period slope failures occur mainly in the low latitudes and are associated with lowering sea level. This finding suggests that reduced hydrostatic pressure and the associated destabilization of gas hydrates may be the primary cause. The Bølling-Ållerød sediment failures were predominantly low latitude, suggesting an early tropical response to deglaciation, e.g., enhanced precipitation and sediment load to the continental shelf or warming of intermediate waters. In contrast, sediment failures during the Preboreal period and the majority of the Holocene occurred in the high latitudes, suggesting either isostatic rebound–related earthquake activity or reduced hydrostatic pressure caused by isostatic rebound, causing destabilization of gas hydrates.
— Maslin, M; Owen, M; Day, S; Long, D (2004). "Linking continental-slope failures and climate change: Testing the clathrate gun hypothesis". Geology. 32 (1): 53. doi: 10.1130/G20114.1. ISSN 0091-7613.
If we read further down the article, we see it talks only about continental slopes. It was taken out of context.
@
Prokaryotes: I see that you added this to the article, could you please review it? —
Arthurfragoso (
talk) 04:49, 15 July 2019 (UTC)
References
From what I'm reading now is that the Clathrate gun hypothesis only counts for seabed Clathrate, I was probably thinking the hypothesis included terrestrial clathrate, IPCC does not clarify much either. If we read the IPCC Climate Change 2013: The Physical Science Basis:
Anthropogenic warming will very likely lead to enhanced CH 4 emissions from both terrestrial and oceanic clathrates. Deposits of CH 4 clathrates below the sea floor are susceptible to destabilization via ocean warming. However, sea level rise due to changes in ocean mass enhances clathrate stability in the ocean. While difficult to formally assess, initial estimates of the 21st century feedback from CH 4 clathrate destabilization are small but not insignificant. It is very unlikely that CH 4 from clathrates will undergo catastrophic release during the 21st century (high confidence).
— IPCC Climate Change 2013: The Physical Science Basis. p.71
A very large geological stock (globally 1500 to 7000 PgC, that is 2 x 10 6 to 9.3 x 10 6 Tg(CH 4 ) in Figure 6.2; Archer (2007); with low confidence in estimates) of CH 4 exists in the form of frozen hydrate deposits (‘clathrates’) in shallow ocean sediments and on the slopes of continental shelves, and permafrost soils. These CH 4 hydrates are stable under conditions of low temperature and high pressure. Warming or changes in pressure could render some of these hydrates unstable with a potential release of CH 4 to the overlying soil/ocean and/or atmosphere. Possible future CH 4 emissions from CH 4 released by gas hydrates are discussed in Section 6.4.7.
— IPCC Climate Change 2013: The Physical Science Basis. p.473
Model simulations (Fyke and Weaver, 2006; Reagan and Moridis, 2007; Lamarque, 2008; Reagan and Moridis, 2009) suggest that clathrate deposits in shallow regions (in particular at high latitude regions and in the Gulf of Mexico) are susceptible to destabilization via ocean warming. However, concomitant sea level rise due to changes in ocean mass enhances clathrate stability in the ocean (Fyke and Weaver, 2006). A recent assessment of the potential for a future abrupt release of methane was undertaken by the U.S. Climate Change Science Program (Synthesis and Assessment Product 3.4 see Brooke et al., 2008). They concluded that it was very unlikely that such a catastrophic release would occur this century. However, they argued that anthropogenic warming will very likely lead to enhanced methane emissions from both terrestrial and oceanic clathrates (Brooke et al., 2008). Although difficult to formally assess, initial estimates of the 21st century positive feedback from methane clathrate destabilization are small but not insignificant (Fyke and Weaver, 2006; Archer, 2007; Lamarque, 2008). Nevertheless, on multi-millennial time scales, the positive feedback to anthropogenic warming of such methane emissions is potentially larger (Archer and Buffett, 2005; Archer, 2007; Brooke et al., 2008). Once more, due to the difference between release and accumulation time scales, such emissions are irreversible.
— IPCC Climate Change 2013: The Physical Science Basis. p.1116-1117
I now see the hypothesis was defined in the 'Methane Hydrates in Quaternary Climate Change: The Clathrate Gun Hypothesis' book. I will read it to see how broad it is.— Arthurfragoso ( talk) 01:40, 16 July 2019 (UTC)
I found this image at Commons. I suppose that it could be used in this article. -- Andrew Krizhanovsky ( talk) 13:34, 9 August 2019 (UTC)
I think the lead is not a good summary of this article. It seems to say that this hypothesis is not relevant in the current climate change situation but in the main text there is a long segment that explains the current issues. Pinging User:InformationToKnowledge. You have used long excerpts from this page at arctic methane emissions. The whole setup of the four articles seems to be not ideal: permafrost, permafrost carbon cycle, clathrate gun hypothesis and arctic methane emissions. I like excerpts but when the excerpts are very long, and don't take from the lead, I get a bit suspicious if the structure of the articles is right and if they fit together well. EMsmile ( talk) 10:43, 18 September 2023 (UTC)
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I have written to Professor Kennett of UCSB for a summary of the state of the knowledge on this topic. I also wrote to a NCAR researcher to find out if this hypothesis is modelled in the AOGCMs. Simesa 18:58, 18 May 2006 (UTC)
This article states the global warming potential of atmospheric methane as 23 over 100 years; the methane clathrate article states the same potential as 21 over 100 years. Which is more accurate? —Preceding unsigned comment added by 66.74.164.155 ( talk) 15:19, 21 November 2009 (UTC)
I was looking at both the page on Methane and this one and I noticed some dissimilar information on the effects of methane on the greenhouse gas effect. Most notably, the exact figures of the effect of methane. This page does not seem to have a citation for the figures, where as the methane page does. One of these instances cites the half life of methane at 12 years in the atmosphere where as the methane page has values of 9.6 years and 8.4 years, depending on the level of atmosphere. If the 12 year value is correct, could someone please document it? The methane pages also mentions the environmental impact with "Because of this difference in effect and time period, the global warming potential of methane over a 20 year time period is 72." This value is much different than the one on this page. —Preceding unsigned comment added by Spotowski ( talk • contribs) 22:26, 14 March 2009 (UTC)
In its original form, the hypothesis proposed that the "clathrate gun" could cause abrupt runaway warming (A) in a timescale less than a human lifetime, (B) [1] and might be responsible for warming events in and at the end of the last ice age (C). [2] This is now thought unlikely.[3][4]
Which is "now thought unlikely", A, B or C? 67.52.81.242 ( talk) 04:54, 14 November 2010 (UTC)
Let us put this way, we hope it won't happen and based on what we think us know today it will not be able to do it. But then there are those evidence that see an accelerating methane in the shallow seas of the arctic, combined with studies that recently questioned our beliefs of the time rate of earlier historical methane releases, instead of placing it between 400-1300 y now think it can happen in a century or two? Myself I expect a cocktail of effects accelerating all temperature raises, and there methane definitely will be included. And there's one thing more, until recently we thought that the main problem with bogs etc would be the methane, but 'experimenting', separating and partially drying a lake in Siberia, it was found that a considerable amount of CO2 will be contributed. http://news.softpedia.com/news/Warming-Tundra-Releases-Carbon-Dioxide-118363.shtml
And if you look at timescales CO2 have an expected tail of influence, at least a millennium long, which makes it our number one priority. As long as methane doesn't accelerate into a giant 'spike' we won't get a tipping from that alone, and its timescale of influence is decades instead of millenniums. But then there is that possible 'spike'? I don't know, I sincerely hope it never will come to that though as .. I'm sure you can figure out why I hope so yourself.
Look up "Methane release from the East Siberian Arctic Shelf. by Natalia Shakhova, Igor Semiletov."
Yoron. 178.30.89.241 ( talk) 23:15, 17 June 2011 (UTC)
now thought unlikely
IMO this statement should be removed. Both of the citations for the statement are from 2006. Meanwhile the article cites empirical data from 2008 (Shakhova et. al) that pretty much tells the opposite story. This scenario isn't unlikely as it is already happening at the estimated rate of 0.5 Mt/y! Why does the first intro phrase to "Current Outlook" still read modelling by Archer (2007) suggests the methane forcing should remain a minor component of the overall greenhouse effect.[17] when there is more recent empirical data suggesting something else? Does Archer's model predict the data gathered in 2008? If not it should not be mentioned in such a prominent place - a model that doesn't validate against the present is certainly not predicting the future. Is a climate scientist here to comment on this? I'm a software engineer working in this field (atmospheric simulations), but I don't feel qualified to do a full edit on this article, I just feel it has serious contradictions. If no-one steps forward I will do an attempt anyways however. Muellermichel ( talk) 15:04, 17 June 2016 (UTC)
The ambiguous statements attributed to Ryskin 2003 appear to be out of date, as does the lead section "however" attributed to BBC 2002. Viriditas ( talk) 10:39, 30 November 2012 (UTC)
Likewise regarding the statement that "the existence of vast oceanic methane clathrate formation is uncertain and usually only based on reflective seismology and pieces larger than 10 cm have only been recovered from three sites." The statement references a publication by Jean Laherrere from May, 2000, which was probably correct at the time. I'm pretty sure that in the 12+ years since then, the uncertainty has been substantially reduced. There have even been experimental drilling campaigns by the Japanese to test the feasibility of commercial development. I don't have a reference, offhand, and the article(s?) I recall didn't report a definitive yes / no as to commercial feasibility, but the drilling did achieve some level of production. Agnostic Engineer ( talk) 19:39, 7 January 2013 (UTC)
Princeton University issued a news release entitled: "On warmer Earth, most of Arctic may remove, not add, methane"; from the article: "new research led by Princeton University researchers and published in The ISME Journal in August suggests that, thanks to methane-hungry bacteria, the majority of Arctic soil might actually be able to absorb methane from the atmosphere rather than release it. Furthermore, that ability seems to become greater as temperatures rise.
The researchers found that Arctic soils containing low carbon content — which make up 87 percent of the soil in permafrost regions globally — not only remove methane from the atmosphere, but also become more efficient as temperatures increase. During a three-year period, a carbon-poor site on Axel Heiberg Island in Canada’s Arctic region consistently took up more methane as the ground temperature rose from 0 to 18 degrees Celsius (32 to 64.4 degrees Fahrenheit). The researchers project that should Arctic temperatures rise by 5 to 15 degrees Celsius over the next 100 years, the methane-absorbing capacity of “carbon-poor” soil could increase by five to 30 times.
The researchers found that this ability stems from an as-yet unknown species of bacteria in carbon-poor Arctic soil that consume methane in the atmosphere. The bacteria are related to a bacterial group known as Upland Soil Cluster Alpha, the dominant methane-consuming bacteria in carbon-poor Arctic soil. The bacteria the researchers studied remove the carbon from methane to produce methanol, a simple alcohol the bacteria process immediately. The carbon is used for growth or respiration, meaning that it either remains in bacterial cells or is released as carbon dioxide."
https://blogs.princeton.edu/research/2015/08/14/on-warmer-earth-most-of-arctic-may-remove-not-add-methane-isme-journal/ Frunobulax ( talk) 20:00, 17 August 2015 (UTC)
NASA recently finished a 5 year mission studying this and said the climate models need to change. 1 — Preceding unsigned comment added by LDWoodworth ( talk • contribs) 16:51, 27 July 2016 (UTC)
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This section needs an update based on new research through to 2018, they found that the clathrates are stable and the extra methane is seeping from rocks below them and has done so for thousands of years since the rise after the last ice age made the layer more permeable. This basically debunks the clathrate gun hypotheseis. I'll edit the article when I get time or someone else might like to do it. See Arctic methane emissions#Contribution to climate change Robert Walker ( talk) 03:16, 6 July 2018 (UTC)
"In addition to potential changes in the magnitude of in a warmer,increasingly ice-free Arctic Ocean (37), we must also consider that the rate of CH4 removal processes, such as aerobic CH4 oxidation by microorganisms in the water column (6,35), could also change. Thus, to accurately constrain the mobilization of ancient C and the subsequent emission of CH4, we recommend that natural abundance14C-CH4analyses should be conducted in future studies of CH4 dynamics."
You may also have noticed I updated the lede - which is now inconsistent with this section which is out of date and so needs more work: Clathrate gun hypothesis#Possible release events needs work. As you'll see from the USGS metastudy [2] and also the cites which I got from the Wikipedia here Permian–Triassic extinction event#Methane hydrate gasification then the clathrate hydrates no longer seem to be considered a viable hypothesis for the PETM.
Also Sparrow et al, 2018 look briefly at a more recent anaogue: [3]says
Although the global atmospheric CH4 inventory is increasing, arctic CH4 growth rates are comparable to or less than the global average (7) and appear to be derived mainly from biogenic sources (2, 8, 9). Ancient C stores, including arctic permafrost and hydrates, were recently determined to have contributed 19% of the CH4 released to the atmosphere during the Younger Dryas – Preboreal abrupt warming event (10), an analog to climate change today.
The paper they cite is here, Petrenko et al, 2017 [5] (ScienceDaily also covered this paper. [6])
"To the extent that the characteristics of the most recent deglaciation and the Younger Dryas–Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur."
We should also mention the IPCC review of methane clathrate research from 2017
"Clathrates: Some economic assessments continue to emphasise the potential damage from very strong and rapid methane hydrate release (Hope and Schaefer, 2016), although AR5 did not consider this likely. Recent measurements of methane fluxes from the Siberian Shelf Seas (Thornton et al., 2016) are much lower than those inferred previously (Shakhova et al., 2014). A range of other studies have suggested a much smaller influence of clathrate release on the Arctic atmosphere than had been suggested (Berchet et al., 2016; Myhre et al., 2016). New modelling work confirms (Kretschmer et al., 2015) that the Arctic is the region where methane release from clathrates is likely to be most important in the next century, but still estimates methane release to the water column to be negligible compared to anthropogenic releases to the atmosphere. A recent review (Ruppel and Kessler, 2017) emphasises that there remains little evidence that clathrate methane is reaching the atmosphere at present. Although methane that is oxidised in the water column will not reach the atmosphere, it will have the effect of further lowering the pH of the ocean (Boudreau et al., 2015). A recent modelling study joined earlier papers in assigning a relatively limited role to dissociation of methane hydrates as a climate feedback (Mestdagh et al., 2017). Methane concentrations are rising globally, raising interesting questions (see section on methane) about what the cause is (Nisbet et al., 2016; Rigby et al., 2017; Schaefer et al., 2016; Turner et al., 2017). finally new measurements of the 14C content of methane across the warming out of the last glacial period (Petrenko et al., 2017) show that the release of old carbon reservoirs (including methane hydrates) played only a small role in the methane concentration increase that occurred then"
Robert Walker ( talk) 21:55, 4 August 2018 (UTC)
Reductions in sea ice and other changes may affect the amount of carbon dioxide absorbed by the Arctic Ocean, while thawing permafrost is expected to increase emissions of methane. However, projections of future impacts on Arctic sources and sinks of greenhouse gases are still hampered by data and knowledge gaps.
Yes - and the thing that made the original CGH alarming is the size of the reservoir that could suddenly be released in the runaway feedback effect where the warming lead to more methane released. The other things such as the subsea and land permafrost can impact on global warming too, but in the articles I've read on the topic, projections so far are significantly smaller than the total global warming effects due to humans, so are more like details - adjusting the projections by a fraction of a degree or some such.
If there isn't enough of a reservoir then you can only have so much feedback effect, mainly just increased due to the global warming from CO2 rather than the methane itself. Also because methane is so short lived in the atmosphere, then even if you have a large reservoir, it still has to be released quickly as well to cause a runaway. With the clathrates there is a large enough reservoir but with the new research, as I understand, the consensus emerging is that it isn't released fast enough for a runaway. Just saying, maybe that needs to be explained to the reader in a little more detail to give it context. As for the subsea and land permafrost then though it's not due to clathrates, it is still relevant to the article I think, maybe it can have a section about whether there can be a runaway methane emission from other causes - and even also the idea of a runaway CO2 effect like Venus and explaining that there aren't enough fossil fuels even if they are all burnt for that to happen, there's the moist greenhouse effect to, which is outcome of a partial CO2 runaway not possible now but could happen a hundred million years in the future in one article I read - don't want to overwhelm the article, more like a short section on related ideas at the end, linking to other articles here on those topics, may be a good idea. I don't have time to read the cites right now, but hope to come back to it soon. Robert Walker ( talk) 13:56, 5 August 2018 (UTC)
Maybe titled something like "Other potential climate change runaway effects" and then briefly go into the other methane sources and how they aren't large enough for a runaway, or like the clathrates, are released too slowly for a runaway - and then the CO2 runaway hypothesis which briefly was thought to be theoretically possible if we burn all the fossil fuels, but soon disproved. Robert Walker ( talk) 14:08, 5 August 2018 (UTC)
That would also help with potential confusion of CH4 and CO2 runaways. Robert Walker ( talk) 14:09, 5 August 2018 (UTC)
All I can say about my topic ban is that broadly construed means that I am not permitted to comment on or even hint at anything to do with the topic or anything that lead to my indef topic ban on Buddhism. About the only thing I am permitted to say is that I am Buddhist, and if asked what that means I can't answer that either. Can I ask you kindly to not discuss it futher here with other editors, as I am not permitted to respond.
Please though decide for yourself whether I am doing a wall of text here, rather than rely on what others said about me in an unrelated discussion, in an unrelated topic area. I am involved in many other editing areas and with one other exception, which I can talk about, I have never been accused of walls of text in any other topic on Wikipedia, even when both myself and the other editor write multiple pages of content. This is because what I write is always directly relevant to improving the article. See for instance these long discussions on microtonal music with another editor with equally long responses and you can see how my responses are appreciated by them and vice versa Talk:Regular diatonic tuning#Meantone temperament. That is with the exception of Life on Mars and Planetary Protection. If you look further back then you will find discussions I can talk about related to the topic of habitability of present day Mars. There was a great fracas about that during which I was accused of walls of text and trolling, which you can find if you search back in my history - but do bear in mind - the final outcome after one of the opposing editors who was opposing my content on Wikipedia left for a six month sabbatical was that I wrote the articles Modern Mars habitability and Present day Mars habitability analogue environments on Earth which were so obviously good and well researched that nobody has suggested they should be deleted - they give an idea of the quality of my work on Wikipedia, even though I had had opposition for several years from an editor who prevented me from adding any material on these topics to the encyclopedia. They have only had minor edits by wikignomes - I am the sole author. And I wrote half of the article Planetary protection and nearly all of Interplanetary contamination after the fuss died down about my attempt to add extra material on these topics.
If we already have too much material to discuss, without going into this idea of an extra section for the article to help clarify the connection with other runaways and with CO2 feedback, then that's fine by me. It was just a suggestion. In case it wasn't clear I was responding to this part of what you said:
"What is misleading is bad writing (whether its here or somewhere else) that fails to explain issues related to greenhouse gases in something of a venn diagram fashion. As we all know here, methane is just one of the GHGs (but readers are confused about this). I can hear it now, "C4... isn't that carbon dioxide?" Once the reader undstands there are different compounds in natural sinks/sources, and the reader focuses on methane, there are many different processes to talk about."
This suggestion of an extra section, which I sketched out in my response, was an idea of how to help with that. But we can leave it for future discussion! Got plenty of other things to do :). Robert Walker ( talk) 15:27, 5 August 2018 (UTC)
On your second comment, yes I can work on those articles, if I have time. I haven't checked, I'd have thought they would cover these topics. Perhaps the suggestion wasn't clear? I didn't mean a new section going into that in detail. I meant a short section that just explains the basic idea of a runaway and why the clathrates are not a runaway if the emissions are small compared to other effects - and a one or two sentence mention of other methane sources and a brief explanation of why they are not considered to be capable of a runaway either (unless of course any are but I don't think they are) and of the CO2 runaway hypothesis and why that also is now discounted - the whole thing just one short para with interwiki links to find out more. I think this would add to clarity of this article. Robert Walker ( talk) 15:39, 5 August 2018 (UTC)
"Short-term temperature warming has limited impact on the gas hydrate stability. We show that warming can significantly affect gas hydrates in the seabed only when ocean temperature is constantly rising for several centuries,"
"The increase of methane flux started several hundreds to thousands of years ago, which is well before any onset of warming in the Arctic Ocean that others have speculated,"
Hope you don't mind - easier to read if not indented too far.
I see you have made many other changes throughout the article including a major rewrite of the lede, generally in the direction of making the clathrate gun hypothesis seem more plausible as an ongoing still viable theory. I don't have time to discuss such major chagnes right now.
I know what it can be like on Wikipedia with these discussions and I don't have enough time on my hands to go through this and especially not in an area where I have been advised there are discretionary sanctions, which means that emotions run high, and can even mean that someone might unexpectedly take you to WP:ANI mid conversation unexpectedly, and that I most definitely do not have time for. I mean not suggesting you would, but someone might, if feelings run high..
I thought I was just doing simple fixing of an article that was a bit out of date, and didn't include the latest research. This is the type of work I prefer in Wikipedia and I have no stomach for controversial areas, nowadays, especially not after various bad past experiences here.
But if I can make a couple of suggestions, I think the lede should cite the USGS and IPCC surveys if you are going to cite that 2018 one, especially because they are not behind paywalls and are highly regarded too. We cite articles that the readers can check for themselves where possible and as they are from 2017 they are hardly out of date.
And I don't know why you removed the material from the lede about how scientists used to think the PETM warming was due to clathrates decomposition and that this was later disproved. Indeed you have dealt with this matter of the "Possible release events" section by just deleting the entire section, and all mention of connection with past events. I think it is of great interest to the reader to know that this hypothesis has been disproved. Because it casts significant doubt on whether it could happen today if it didn't happen in the PETM or in the Lower Dryas temperature excursion. Meanwhile in articles and blog posts off wiki they will read that it happened in the PETM and will come here assuming that and will read an article that does not disabuse them of this now out of date idea..
Normally when editors plan such substantial changes to an article then they discuss it on the tal pages first. I did that before my edits. The only reason I went ahead and edited it was because no-one replied. Then when nobody responded to my edits either - I went on and continued to edit it as an apparently dormant article that nobody was much interested in. If I had thought there was interest from other editors I'd have discussed it all here first. It was because nobody responded so I did as is advised to "be bold" and do the edit anyway.
I never do substantial or possibly controversial edits before discussing them on the talk page first. Not in all the time I've been on Wikipedia. That is just not how I do things. For instance with the habitability of Mars and the Planetary protection issues, I discussed all my edits on talk pages first, went ahead and did them, worked on them for some months - and they were there for some time before someone came along and decided to remove the material from wikipedia. When that happened I then tried to resolve the issue on the talk pages. That is how I operate.
Especially here - there's the risk of emotions running high, of someone deciding to take you to WP:ANI, and also, that when an article is so much in flux then in my experience probably this means it is going to flip flop between different versions of the text and be edited and re-edited for possibly a long time - and I haven't the time to work through that right now.
But I have found this discussion so far rather useful, and I hope you have too. I might write my own article based on all this off wiki, on Quora or my science blog, to help clarify ideas and then maybe can come back here at a later date once the ideas are clearer here and see if I can help with whatever form it is in by then. Just not now when it is in such flux.
But good luck with the article and I hope you get some clarity here! I may come back a bit later and see what has happened. Robert Walker ( talk) 04:40, 6 August 2018 (UTC)
Oh my apologies! Not to excuse it but for understanding - it's maybe partly because of previous bad experiences here on Wikipedia. I over-reacted. I see that your edit was mainly moving things about rather than removing them. The sections that I thought were just gone were moved somewhere else.
It is clearly mid edit and you may have more changes you want to do and the USGS cite especially is vast - no way I have time to read it in detail at the present, just read some sections especially relevant to the clathrate gun hypothesis and their overview "press release" style page. I expect probably you haven't either yet, just because it is so long, and a very technical paper, and a new cite here. I strongly recommend reading it. Seems to be the best most authoritative work there is out there on this topic and essential background reading. And the other articles are also rather technical and most can probably do with a re-read. It is easy to make mistakes - even Phys.org did when they wrote 1.8 C instead of -1.8 C and they are generaly a reasonable WP;RS. Just a mistake on their part and we can make mistakes too.
I think though that I should leave further comment until whatever time you feel you have read the cites we've been discussing, integrated them into you rewrite, and feel happy with the article. Then do post here and say your rewrite is done. Then I can comment on it. I am very happy to let someone else do the work of the rewrite, so long as it is part of a conversation and we are working on the article together rather than just taken into their heads to do a major rewrite without discussing it first, as happens here on Wikipedia sometimes - I first encountered that with the Mars / Habitability where one editor just went around Wikipedia removing all the content in all the articles anything to do with planetary protection, and another editor removed all material anything to do with the present day habitability of Mars. The motivation is a little unclear but the one removing the planetary protection article was quite specific he said he was sick of seeing sections in the articles on concerns about forward contamination of Mars by microbes brought there by human colonists. So he had a pro-colonization political motivation for removing this material. Eventually he deleted nearly all of the main planetary protection article. It was quite shocking, for a weeks Wikipedia had almost no material on this topic. Since then I have been able to restore just about all the material that was deleted and in much improved form too with many cites. Anyway I was a bit worried you were acting like him, sorry!
Thanks! Robert Walker ( talk) 05:36, 6 August 2018 (UTC)
Recent observations of extensive methane release from the seafloor into the ocean and atmosphere cause concern as to whether increasing air temperatures across the Arctic are causing rapid melting of natural methane hydrates. Other studies, however, indicate that methane flares released in the Arctic today were created by processes that began way back in time – during the last Ice Age.
Newest research from the Center for Arctic Gas Hydrate, Climate and Environment (CAGE) shows that methane has been leaking in the Arctic for millions of years, independent of warm or cold climate. Methane has been forming in organic carbon rich sediments below the leakage spots off the coast of western Svalbard for a period of about 6 million years (since the late Miocene). According to our models, methane flares occurred at the seafloor for the first time at around 2 million years ago; at the exact time when ice sheets started to expand in the Arctic.
The acceleration of leakage occurred when the ice sheets were big enough to erode and deliver huge amounts of sediments towards the continental slope. Methane leakage was promoted due to formation of natural gas in organic-rich sediments under heavy loads of glacial sediments. Faults and fractures opened within the Earth’s crust as a consequence of growth and decay of the massive ice masses. This brought up the gases from deeper sediments higher up towards the seafloor. These gases then fueled the gas hydrate system off the Svalbard coast for the past 2 million years. It is, to this day, controlling the leakage of methane from the seabed.
Just to make it clear, as you didn't respond, do say when your revision is complete, @ Prokaryote:. Because I made a number of specific criticisms in our last conversation that have not been addressed. Rather than dive in and edit it and possibly end up in an edit war, I think it has to be discussed on the talk page first.
Once it is finished do let me know and I will do a bulleted list of the main things I think need to be fixed, or at least, discussed, and then we can come to some kind of resolution and mutual agreement / understanding on what the reliable sources are saying. Or if there are differences in views in the literature, then to make sure all the views are expressed in the article. In several key points I think the current article doesn't express what the literature says quite yet.
I will read the USGS overview article first and re-read some of the cites here before commenting on your final version of the article. I'm going to do that anyway when I find time. Do take your time, and spend as much time as you need on your rewrite, but I'd like to know when it is finished. Thanks! Robert Walker ( talk) 10:40, 7 August 2018 (UTC)
"Clathrates: Some economic assessments continue to emphasise the potential damage from very strong and rapid methane hydrate release, although AR5 did not consider this likely. Recent measurements of methane fluxes from the Siberian Shelf Seas are much lower than those inferred previously. A range of other studies have suggested a much smaller influence of clathrate release on the Arctic atmosphere than had been suggested.
…. A recent modelling study joined earlier papers in assigning a relatively limited role to dissociation of methane hydrates as a climate feedback. Methane concentrations are rising globally, raising interesting questions (see section on methane) about what the cause is, finally new measurements of the 14C content of methane across the warming out of the last glacial period show that the release of old carbon reservoirs (including methane hydrates) played only a small role in the methane concentration increase that occurred then."
"Our analysis of sediment cores of Western Svalbard unambiguously confirms that retreat of the Barents Sea ice sheet led to offshore gas hydrate dissociation, a process that has been widely speculated upon from modeling and geological observations3, 5, 38,39,40,41 but up until now, has remained unproven. Furthermore, combined modeling and geochemical analysis reveals that methane hydrates at the up-dip limit of the hydrate stability zone decomposed via postglacial isostatic rebound in contrast to previous hypotheses that invoke anthropogenic bottom water warming7, 9. Our data and model results also show that gas hydrates are not in themselves a significant source for gas release at the seabed. Rather, they act as a dynamic seal that blocks fluid-flow pathways for gas migration from deep geological reservoirs."
Robert Walker ( talk) 14:22, 7 August 2018 (UTC)
See WP:LEADSECTION. The lead must be a summary of the body of the article. If it isn't in the body of the article, it shouldn't be in the lead. In practice, there are frequent exceptions for short and stub articles, but this is neither. NewsAndEventsGuy ( talk) 15:23, 8 August 2018 (UTC)
I'll review and edit as there is time and interest, about all I can say. Follow Wiki rules and do as you will. NewsAndEventsGuy ( talk) 16:16, 8 August 2018 (UTC)
References
In this article introduction, it states:
A 2018 published review concluded that the clathrate gun hypothesis remains controversial, but that better understanding is vital. [1]
So I opened the article to see in what point it is controversial, and it states:
In addition to responses of wetland CH4 fluxes to changes in temperature and precipitation, natural CH4 sources such as permafrost soils, lakes, and coastal regions may have all played significant roles in determining the preindustrial CH4 concentration (19). Indeed, loss of large amounts of CH4 from marine clathrate deposits in response to warming (the clathrate gun hypothesis) has in the past been suggested as the primary cause of increases in atmospheric CH4 concentrations during the Quaternary (20). Although the clathrate gun hypothesis remains controversial [2], a good understanding of how environmental change affects natural CH4 sources is vital in terms of robustly projecting future fluxes under a changing climate.
— Reay, Dave S.; Smith, Pete; Christensen, Torben R.; James, Rachael H.; Clark, Harry (2018). "Methane and Global Environmental Change". Annual Review of Environment and Resources. 43: 165–192. doi: 10.1146/annurev-environ-102017-030154.
So, let's see what the source of this claim says:
Abstract: It has been suggested that the release of clathrates rather than expansion of wetlands is the primary cause of the rapid increases observed in the ice-core atmospheric methane record during the Pleistocene. Because submarine sediment failures can involve as much as 5000 Gt of sediment and have the capacity to release vast quantities of methane hydrates, one of the major tests of the clathrate gun hypothesis is determining whether the periods of enhanced continental-slope failure and atmospheric methane correlate. To test the clathrate gun hypothesis, we have collated published dates for submarine sediment failures in the North Atlantic sector and correlated them with climatic change for the past 45 k.y. More than 70% by volume of continental-slope failures during the past 45 k.y. was displaced in two periods, between 15 and 13 ka and between 11 and 8 ka. Both these intervals correlate with rising sea level and peaks in the methane record during the Bølling-Ållerød and Preboreal periods. These data support the clathrate gun hypothesis for glacial-interglacial transitions. The data do not, however, support the clathrate gun hypothesis for glacial millennial-scale climate cycles, because the occurrence of sediment failures correlates with Heinrich events, i.e., lows in sea level and atmospheric methane. A secondary use of this data set is the insight into the possible cause of continental-slope failures. Glacial-period slope failures occur mainly in the low latitudes and are associated with lowering sea level. This finding suggests that reduced hydrostatic pressure and the associated destabilization of gas hydrates may be the primary cause. The Bølling-Ållerød sediment failures were predominantly low latitude, suggesting an early tropical response to deglaciation, e.g., enhanced precipitation and sediment load to the continental shelf or warming of intermediate waters. In contrast, sediment failures during the Preboreal period and the majority of the Holocene occurred in the high latitudes, suggesting either isostatic rebound–related earthquake activity or reduced hydrostatic pressure caused by isostatic rebound, causing destabilization of gas hydrates.
— Maslin, M; Owen, M; Day, S; Long, D (2004). "Linking continental-slope failures and climate change: Testing the clathrate gun hypothesis". Geology. 32 (1): 53. doi: 10.1130/G20114.1. ISSN 0091-7613.
If we read further down the article, we see it talks only about continental slopes. It was taken out of context.
@
Prokaryotes: I see that you added this to the article, could you please review it? —
Arthurfragoso (
talk) 04:49, 15 July 2019 (UTC)
References
From what I'm reading now is that the Clathrate gun hypothesis only counts for seabed Clathrate, I was probably thinking the hypothesis included terrestrial clathrate, IPCC does not clarify much either. If we read the IPCC Climate Change 2013: The Physical Science Basis:
Anthropogenic warming will very likely lead to enhanced CH 4 emissions from both terrestrial and oceanic clathrates. Deposits of CH 4 clathrates below the sea floor are susceptible to destabilization via ocean warming. However, sea level rise due to changes in ocean mass enhances clathrate stability in the ocean. While difficult to formally assess, initial estimates of the 21st century feedback from CH 4 clathrate destabilization are small but not insignificant. It is very unlikely that CH 4 from clathrates will undergo catastrophic release during the 21st century (high confidence).
— IPCC Climate Change 2013: The Physical Science Basis. p.71
A very large geological stock (globally 1500 to 7000 PgC, that is 2 x 10 6 to 9.3 x 10 6 Tg(CH 4 ) in Figure 6.2; Archer (2007); with low confidence in estimates) of CH 4 exists in the form of frozen hydrate deposits (‘clathrates’) in shallow ocean sediments and on the slopes of continental shelves, and permafrost soils. These CH 4 hydrates are stable under conditions of low temperature and high pressure. Warming or changes in pressure could render some of these hydrates unstable with a potential release of CH 4 to the overlying soil/ocean and/or atmosphere. Possible future CH 4 emissions from CH 4 released by gas hydrates are discussed in Section 6.4.7.
— IPCC Climate Change 2013: The Physical Science Basis. p.473
Model simulations (Fyke and Weaver, 2006; Reagan and Moridis, 2007; Lamarque, 2008; Reagan and Moridis, 2009) suggest that clathrate deposits in shallow regions (in particular at high latitude regions and in the Gulf of Mexico) are susceptible to destabilization via ocean warming. However, concomitant sea level rise due to changes in ocean mass enhances clathrate stability in the ocean (Fyke and Weaver, 2006). A recent assessment of the potential for a future abrupt release of methane was undertaken by the U.S. Climate Change Science Program (Synthesis and Assessment Product 3.4 see Brooke et al., 2008). They concluded that it was very unlikely that such a catastrophic release would occur this century. However, they argued that anthropogenic warming will very likely lead to enhanced methane emissions from both terrestrial and oceanic clathrates (Brooke et al., 2008). Although difficult to formally assess, initial estimates of the 21st century positive feedback from methane clathrate destabilization are small but not insignificant (Fyke and Weaver, 2006; Archer, 2007; Lamarque, 2008). Nevertheless, on multi-millennial time scales, the positive feedback to anthropogenic warming of such methane emissions is potentially larger (Archer and Buffett, 2005; Archer, 2007; Brooke et al., 2008). Once more, due to the difference between release and accumulation time scales, such emissions are irreversible.
— IPCC Climate Change 2013: The Physical Science Basis. p.1116-1117
I now see the hypothesis was defined in the 'Methane Hydrates in Quaternary Climate Change: The Clathrate Gun Hypothesis' book. I will read it to see how broad it is.— Arthurfragoso ( talk) 01:40, 16 July 2019 (UTC)
I found this image at Commons. I suppose that it could be used in this article. -- Andrew Krizhanovsky ( talk) 13:34, 9 August 2019 (UTC)
I think the lead is not a good summary of this article. It seems to say that this hypothesis is not relevant in the current climate change situation but in the main text there is a long segment that explains the current issues. Pinging User:InformationToKnowledge. You have used long excerpts from this page at arctic methane emissions. The whole setup of the four articles seems to be not ideal: permafrost, permafrost carbon cycle, clathrate gun hypothesis and arctic methane emissions. I like excerpts but when the excerpts are very long, and don't take from the lead, I get a bit suspicious if the structure of the articles is right and if they fit together well. EMsmile ( talk) 10:43, 18 September 2023 (UTC)