dabize
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About dabize
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http://news.sciencemag.org/sciencenow/2012/12/ticking-arctic-carbon-bomb-may-b.html More info on clathrate melting risk magnitude from the SF meeting
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Not sure, although it certainly should have disrupted some methane clathrate beds. The Storegga slide was followed by fairly rapid warming and sea level rise, featuring the flooding of Doggerland (i.e. most of what is now the North Sea) but I always thought that the proximate cause of warming of this period was due to the events that ended the Younger Dryas- i.e.the resumption of the North Atlantic thermohaline current. So the Storegga Slide may well have contributed to this warming, via methane release, but I don't know of any direct proof of it.
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http://www.nature.com/news/gas-hydrates-in-arctic-are-shallowest-yet-found-1.11988 Maybe an explanation for those ridiculously high SSTs near the mouth of the MacKenzie last summer?
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I came across this too......http://www.nature.com/nature/journal/v490/n7421/full/nature11528.html?WT.ec_id=NATURE-20121025 Since hydrates can exist at higher temps as long as they are deeper, then trajectory changes in very warm currents such as the GS certainly might bring large temperature increases to sea floor regions in the Atlantic that contain such hydrates. And the current changes in the Arctic might plausibly produce changes in the thermohaline dynamics of the GS capable of altering its course. Sigh......
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Bumped for some truly crummy news: http://www.bbc.co.uk/news/science-environment-19410444 I sure hope this paper (the Nature paper that is the source of the article) turns out to be another case of Nature's famous "molecular memory" paper, where some people diluted a solution to nullity and claimed that the solvent "remembered" the solute.....................
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It's an emotional thing, too. I for one will mourn the passing of the Karri tree in SW Australia. But what was the deal about "Walmart birds"? Doesn't he know that we killed off the passenger pigeon - the ultimate "Walmart bird"?
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I suppose it was..........but telling us collectively that stopping AGW is not worth redirecting economic activity (especially when such redirection is an economic PLUS) is outrageously counter to the facts (in a rather Rush - ite way) - and did rather invite derision. Mea culpa then........I maintain that your opinion as stated is factually without support and logically flawed, but I take back implications that you are unfit to discuss the point. BTW - its "futile", not "feudal"
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But please don't wipe out the world's economies!!!! It's bad enough already.... Blizzard, take some advice: Stick to forecasting local Wx You have a red tag - presumably you can do that well enough. But complaining about wind farms killing birds in a world where whole mountaintops are being removed to mine coal tells me that you'd better leave the "big picture" stuff to others. And I don't mean Rushbo.
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Hi Terry, The heat may be less of an issue than the pressure.........see my post at Nevens.
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The "blue ice" phenomenon is interesting - at first I though it was regional (limited to fast ice and kettle lakes in the Lena Delta region), then it became clear that much of the CAA has it as well. Lots of Greenland glaciers too. But look at the uploaded file of the Ob'/Taz estuaries as they melted recently (fair weather, 5/28 to 6/9). The ice starts as gray - turns white before melting and assumes a bluish cast only just before the final melt (last frame - Ob' only) So the blue ice does after all have an important regional component, which would favor the involvement of CH4 release (or the blooming of CH4 eating microbiota). I'd have thought the lower Ob' would have LOTS of CH4, though.
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"These seeps were characterized by anomalously high methane fluxes, and in Alaska by ancient radiocarbon ages and stable isotope values that matched those of coal bed and thermogenic methane accumulations." This seems to be the money quote. The release of LIA era CH4 from the Greenland sites may not be of great consequence, since Greenland has not exactly been a compost heap for the past 500 years. However, they seem to have direct evidence that ancient CH4 is being released from melting permafrost in Alaska. Since there could be a very great deal of methanogenic C in/under that permafrost - and since the CH4 from those deposits may have been generating it and then trapping it for thousands of years, there would seem to be some cause for concern......
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I'd like to know how the Greenland Ice cap farts - at least the southern part. Isn't it too soon to see any kind of melt there? Or is it now supporting CH4-producing bacteria that can be metabolically active below freezing and beneath this last winter's snowpack. Inquiring minds, you know...... Also, those images would impress me more if they extended the scale beyond 1870ppm
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http://www.annualreviews.org/doi/full/10.1146/annurev-earth-042711-105329 New paper out concluding that the high rate of CO2 release combined with the resulting ocean acidification that we are seeing today is best comparable with the Permian mass extinction - the largest of them all. The role of acidification and deep ocean anoxia is important, because it suggests that the base of the food chain - ocean invertebrates - may be threatened much more now than during more recent high CO2 episodes (e.g. the PETM), which came on more gradually. This isn't only about CH4, but its implications are certainly not good - hence the post in this thread.
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MauMau tactics of the worst kind. I like the shunning, though. Were you Cotton Mather in a previous life?
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Friv, the clathrate story, as you say, is unsettling enough. I've decided that it is just too unclear to say much about that without better data, which should be available soon. But the link I posted suggested that release from clathrates couldn't be responsible for the low level emission of CH4 from wide areas of the ocean surface, since the CH4 would be exposed to seawater and would be converted to CO2 before it reached the surface. The CH4 clathrate outgassing would be seen only as the "fountains" described by Semelitov and Sharapova in the ESAS, since only in this way would it escape oxidation by the seawater. Broad, low-level CH4 emergence from the ocean surface can be expected only if: a) the water has become saturated and maximally acidified by clathrate CH4, and thus incapable of converting it to CO2, or the CH4 is actually being produced locally at the ocean surface by micro-organisms. Possibility B is bad enough, since it suggests that there is a whole new source of CH4 that we haven't yet accounted for. It's better than A, though.