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Unforced Variations: Apr 2013

Filed under: — group @ 31 March 2013

Open thread for April…

172 Responses to “Unforced Variations: Apr 2013”

  1. 51
    sidd says:

    The always awesome Lonnie Thompson and Ellen Mosley-Thompson and team on annually resolved icecores from Peru for last 1800 yr, Science Express

    paper is at doi: 10.1126/science.1234210

    coverage at

    Jasechko (how do you pronounce ?) et al. in Nature indicate 80-90% of land air water flux is from plants


    coverage at


  2. 52

    What -is- the best consensus right now for how long it would take CO2 to revert back to pre-industrial levels if we halted all emissions? I saw an online model that suggested 900 years but I don’t know at all how well vetted it is.

  3. 53

    #51–From sidd’s link:

    “Due to the remoteness of the ice cap, we had to develop new tools such as a light-weight drill powered by solar panels to collect the 1983 cores. However, we knew there was much more information the cores could provide” Mosley-Thompson said. “Now the ice cap is just a six-hour walk from a new access road where a freezer truck can be positioned to preserve the cores. So we can now make better dust measurements along with a suite of chemical analyses that we couldn’t make before.”

    The cores will provide a permanent record for future use by climate scientists, Thompson added. This is very important, as plants captured by the advancing ice cap 6,000 years ago are now emerging along its retreating margins, which shows that Quelccaya is now smaller than it has been in six thousand years.

    “The frozen history from this tropical ice cap—which is melting away as Earth continues to warm—is archived in freezers at -30ºC so that creative people will have access to it 20 years from now, using instruments and techniques that don’t even exist today,” he said.

    That reinforces a point made before: field work ain’t easy, but it is vital. The caricature of all climate science as consisting of ‘ivory-tower’ modelers ignores a lot.

  4. 54
    MARodger says:

    Todd Bandrowsky @52.
    The conclusions of Archer et al 2009 suggest that 900 years is wildly optimistic. The atmosphere presently hosts 43% of our total emissions from FF & land-use change. The study examines CO2 releases greater than our current total so the ‘substantial fraction’ persisting for ‘tens if not hundreds’ of millenia would be 20% or so.
    The conclusions of Archer et al read as follows:-
    The models presented here give a broadly coherent picture of the fate of fossil fuel CO2 released into the atmosphere. Equilibration with the ocean will absorb most of it on a timescale of 2 to 20 centuries. Even if this equilibration were allowed to run to completion, a substantial fraction of the CO2 , 20–40%, would remain in the atmosphere awaiting slower chemical reactions with CaCO3 and igneous rocks. The remaining CO2 is abundant enough to continue to have a substantial impact on climate for thousands of years. The changes in climate amplify themselves somewhat by driving CO2 out of the warmer ocean. The CO2 invasion has acidified the ocean, the pH of which is largely restored by excess dissolution of CaCO3 from the sea floor and on land and, ultimately, by silicate weathering on land. The recovery of ocean pH restores the ocean’s buffer capacity to absorb CO2 , tending to pull CO2 toward lower concentrations over the next 10,000 years. The land biosphere has its greatest impact within the first few centuries, which is when CO2 peaks. Nowhere in these model results or in the published literature is there any reason to conclude that the effects of CO2 release will be substantially confined to just a few centuries. In contrast, generally accepted modern understanding of the global carbon cycle indicates that climate effects of CO2 releases to the atmosphere will persist for tens, if not hundreds, of thousands of years into the future.

  5. 55
    mikeworst says:

    ” Chuck @44 – I agree with a lot of that, although I’m sure a lot of scientists are quietly (and sometimes loudly) doing a lot more than we are seeing.” Yup changing their minds.

  6. 56
    David B. Benson says:

    Sahara Went from Green to Desert in a Flash
    Easy come, easy go.

    Point at the very end is interesting.

  7. 57
    andrew adams says:

    A quick shout out to people in the UK with Sky/Virgin – PBS UK is showing “Climate of Doubt” next Thursday @ 9pm.

  8. 58
    caerbannog says:

    For those who are interested, there’s a new version of the “global temperature virtual machine” file at

    Quickie changelog:

    1) Fixed an embarrassing typo-bug (a “fatfinger” blunder that I had introduced that resulted in some station data getting chopped off). Results are improved ever so slightly with this bug fix.

    2) Moved the plot legend where it’s less likely to be obscured by the temperature curves.

    3) Added some simple statistical computations: the crosscorrelation between the program’s results and the official NASA results, and a “not quite R-squared” statistic — I compute the mean-square error between the program results and the NASA results, divide by the variance of the NASA results, and then subtract that ratio from 1. It seems to give a better measure of the similarity between the program results and the NASA results than the proper R-squared statistic does.

    4) Added a desktop icon that launches a text editor with the program results (so that the actual numbers can be copy/pasted out of the virtual machine).

    Obligatory disclaimer: This is not a sophisticated analysis tool — the temperature averaging algorithm is quite rudimentary. That being said, it does do a nice job of demonstrating the robustness of the NASA global-temperature results.

  9. 59
    sidd says:

    I am rereading

    Regarding Fig 1) and the comment later in the page:

    “Additionally, models based on snowpack properties suggested that some 2012 meltwater remained unfrozen at 5 meters depth (approximately 16 feet) in mid-December. The model results are consistent with observations from JAXA’s AMSR-2 sensor.”

    Looking at the left hand side in Fig 1) the area indicated looks like 1e4 km^2
    meltwater as deep as 5 m looks like about 1mm sea level rise just waiting to melt when the sun hits it.

    Floods like last year but in SE Greenland this time instead of SW ? Or both ? I am informed by Neven’s sites that Jacobshawn has been clearing it’s throat


  10. 60
    Hank Roberts says:

    Fred Pearce, sigh:

    Shorter: it’s not global warming if it’s the oceans warming, so global warming has slowed down, because the oceans are where the warming is going, so it’s not global, so it’s not warming.

    Or something. I can’t follow his logic.

    Hat tip to Metafilter

  11. 61
    MARodger says:

    Hank Roberts @60.
    I don’t find much that is negative in Fred Pearce’s explanation of the recent surface temp record. His concluding lines are not a bad take-away (though perhaps could do with their own paragraph and I’d write it as a single sentence without the question mark).
    “Whatever happened to global warming? The odds may be that by 2020 it will have come roaring back.”

    I do have one gripe, mind. He says near the top of his article “Something is going on. With heat-trapping greenhouse gases accumulating in the atmosphere ever faster, we might expect accelerated warming. So it needs explaining.”
    This is wrong. Sure CO2 & N2O may have accumulated ‘ever faster’ but CH4 has taken a bit of a holiday while the various CFCs & other minor GHGs have pretty-much retired from increasing AGW.
    The upshot is that ‘heat-trapping greenhouse gases are not accumulating in the atmosphere ever faster’ and for the likes of Fred Pearce to say otherwise is very poor do’s.

  12. 62
    David B. Benson says:

    Rapid Climate Change and the Role of the Southern Ocean
    Very clear explanation of the importance of windblown dust.

  13. 63
    David B. Benson says:

    Deepwater Horizon: Gulf of Mexico ‘deep-cleaned’ itself
    The bit about ocean floor oil seeps is certainly climate related.

  14. 64
    MARodger says:

    Sadly the take-away message that Williams & Joshi 2013 probably put quite some thought into – “Aviation is partly responsible for changing the climate, but our findings show for the first time how climate change could affect aviation.” – has so readily lost half its message by the time it reaches the media.
    Air travel continues to expand with no obvious solutions to its climatic significance – and that significance is not small. I have long advocated that airliners should be required to carry a health warning painted large down the fuselage – FLYING THIS PLANE IS GONNA KILL.

  15. 65
    Adam says:

    Anyone at and blogging the EGU?

  16. 66
    Steve Elfelt says:

    Antarctic bottom water, “global warming stopped”, and ocean heat content


    I noticed in the latter article they were pondering whether the southern pacific will continue to play as great a role as a heat sink as it has in the past. I read into this an implication that may or may not have been implied, and the question I read into it was “Could the heat sink function be slowing?” In this comment I am musing whether disappearance of this Antarctic bottom water could actually *speed up* energy transfer to the ocean depths, thus giving us a false sense of security due to a temporarily enhanced heat sink.

    I’m only an amateur nerd so I’m sure this isn’t a new thought for professional nerds but here goes…. if this Antarctic bottom water is forming at the surface off the continent and then sinking into the basins and spreading across the floors of the other oceans (sort of suggested in the first link above), what’s that mean? To me its almost like an atmospheric inversion…. very cold, dense salty water at the bottom of the sea….. in the past, how was a poor global warming BTU added to the ocean surface supposed to get DOWN there? (Answer, very slowly)

    If the factory that makes this water (certain offshore regions around Antarctica) stop making it, doesn’t that mean the anti-mixing characteristics of the ocean depths are undergoing some profound changes? Seems like a new “normal” in terms of up-down heat transfer has to be created, if the dominant player is taken out of the game.

    Of course, that could go either way. Lacking a hypothetical mechanism to create some new type of anti-mixing layering, it seems reasonable to think we are simply propping open the lid to the deep-ocean chest freezer. And that, in turn, might be a key reason why the rate of increase in surface temps allegedly slowed down these last few years.

    Probably an insufficiently educated ramble. Rip tear snarl away!

    [Response: Our oceanography experts at RC may have more to say on this, but you’re overall take is correct. Climate models frequently show that Southern Ocean being a major heat sink for some time to come, and indeed many would attribute to this the relatively modest amount of warming seen over most of Antarctica (though I think those observations actually have more to do with atmospheric circulation changes than ocean dynamics). We ought to do a post on all this, and I’ll try to do that in the near future. –eric]

  17. 67

    Another one bites the dust:

    OK, 12 years beyond expected lifespan & a successor in orbit, but still.

  18. 68
    Turboblocke says:

    April 10, 2013

    Some landowners are suing some energy and chemical companies. What is interesting is the companies’ defense…
    “In their petition for a review by the full 5th Circuit, the companies argued that global warming was not attributable only to them but resulted from the emissions of greenhouse gases from millions of sources dating back to the Industrial Revolution.”

    So if even they are not denying AGW and it’s causes, that shows just how far removed from reality the deniers are.

  19. 69
    Chuck Hughes says:

    This appeared on another thread but I didn’t notice a response to it so I thought I would post it here:

    My question is…. What exactly does this mean? I was reading other comments on Dailykos in response to FishOutOfWater’s post and nobody understood the implications. Most of the comments were that everything went fuzzy after the first couple of paragraphs of reading this. Is the Antarctic ice melting or increasing? What is “Bottom Water” and how is this having an effect on Antarctic ice?

    What does it mean when you say Half of the Global Thermohaline Circulation Is Faltering? How serious is this and what is causing it?

    Again, sorry to interrupt the discussion but us average folks would like to understand this a little better. Thanks.

  20. 70

    #69–Chuck, the confusion is understandable IMO; though the article had some good information, it wasn’t very tightly focussed.

    Here’s a brief definition of ‘bottom water’:

    In oceanology, bottom water is by the ocean floor. It has characteristics are markedly distinct from the above layer in terms of oxygen content, salinity, bulk temperature (characteristic temperature), and hence density.
    The Antarctic Bottom Water is the source of most bottom water in southern parts of Pacific Ocean, Indian Ocean and Atlantic Ocean, and even in parts of the North Atlantic. Bottom waters flow very slowly, driven mainly by slope topography and differences in temperature and salinity, especially compared to wind-driven surface ocean currents.


    The article says–and supports the contention with literature citations pretty convincingly, at least as far as this layman can tell–that rates of formation of bottom water are decreasing. This is associated with the formation of relatively fresh ‘ponds’ of meltwater in the top tens of meters of the water column. So increased ice melt is (perhaps) causing the decrease in bottom water formation.

    I didn’t get the sense that anyone really knows in detail what this will imply for the circulation of Southern Hemisphere oceans, though obviously you’d expect that the ‘sign’ of the change should be negative–that is, the circulation should slow overall.

    One speculation might be that advection of warmer water toward Antarctica might slow. But I wouldn’t put much stock in that in advance of some actual study. I thought the comment in the story you link was a pretty good summary from someone–Deward Hastings–more knowledgeable than me (not a high bar to meet!):

    That lens of (relatively) fresh water that is forming around Antarctica is challenging, and changing, almost everything in global circulation patterns. It freezes sooner (and at a higher temperature). That shields the water from the wind, and reduces wind-driven mixing. It reduces, perhaps to the point of stopping altogether, the present global ocean circulation patterns. That in turn will change global atmospheric weather.

    Nobody knows exactly what comes next. We’ve never seen it happen, and our models, not terribly accurate in describing the world we know, are completely untested in the coming world that we don’t know.

    Without a constant flow of cold water from the poles the Abyss will warm . . . and without cold slowly rising from the Abyss the mid-ocean and ocean surface will warm (already happening). That will lead to more evaporation (driving a different haline circulation in the tropics) and stronger tropical winds driving different surface currents and greater mixing.

    One of the ‘key studies’ is probably this one:

    It would be worthwhile to look up the cross-referenced studies listed at the bottom of the pages.

    Hope all that helps!

  21. 71
    Steve Elfelt says:

    @Chuck 69,

    I’m obviously interested in all this, too (see my earlier comment). What I think I remember from my undergrad goes like this…..

    First, I found the 2nd image at this page to be very helpful

    Think of a conveyor belt. Somewhere it goes down, then across, then back up, and returns to its origins. We’re all familiar with rubber conveyor belts in warehouses and the like. Oceans do the same, sorta. The image I mentioned shows 6 places where the ocean water becomes more dense due to changes in salt and temperature. Being dense, this water sinks. That’s the “down” on the conveyor belt. As it sinks, surface water flows in to maintain sea level. So it follows that somewhere else water is rising, right? After sinking “bottom water” flows at depth to places where the water rises. And the belt goes around.

    We appear to be turning off two of the six areas we know where loops of this “ocean conveyor belt” go down. It defies reason to think this won’t bring about a great deal of change as the system looks for a new equilibrium.

    Part of the implication is the distribution of heat from the tropics to the poles. Incoming sun shines in a tighter beam when the sun is high (like in the tropics) instead of low (like at the poles). Try it yourself with a flashlight straight at the wall or oblique. So all that water in the tropics with the sun overhead is getting heated, and this conveyor belt in the past was transporting all that heat towards the poles (to where changes in salt and temp made the water dense, causing it to sink). But if that water isn’t sinking anymore, where’s the heat that used to flow with the conveyor towards the poles going to go?

    It’s gotta go SOMEWHERE, and since its a new paradigm, human institutions, cultures, and infrastructure may or may not continue to be a good fit with the new equilibrium. Its delusional to think there will be no paradigm busting changes. At this point, I think there are many big ideas about which currents will change, and how atmospheric patters will change, but it seems to me there is a large bit of “we don’t know that we don’t know”, especially in the realms of chaos theory and synergistic effect. We’re really good a reductionist thinking, but less willing to think in terms of systems. And that’s one of the main problems >>>> this is a systems issue, and for policy-moving evidence we still rely on computer models that require reductionist data inputs.

    Probably didn’t add any more background than you knew, but maybe some of that will help others.

  22. 72
    Chuck Hughes says:

    Thank you Steve and Kevin. I will try to pass this information along to others if that’s okay with you. FishOutofWater posts a lot of information about the climate on Dailykos and does a really good job of explaining things most of the time but some of these concepts are just too difficult for the average reader who lacks the background needed to understand it.

    This seems to go with the whole Gulf Stream slowing, albeit in a different part of the globe and for slightly different reasons. Basically when you heat up the polls it slows down circulation with air and water, as far as I can tell, which in turn cause weather patterns to stagnate and become more erratic and unpredictable. I assume that’s what we’re experiencing now with the jet stream being in an almost vertical position, if I understand it correctly. Again, thanks for taking the time to explain.

  23. 73
    Steve Elfelt says:

    Fine with me to forward my contributions, but please add that I’m just a poor layman with a BS degree in natural resources and I’m speculating in this post…. certainly not hypothesizing as a professional. As for the Gulf Stream, I’ve heard it could slow too. But on the other hand, when I was looking at papers about it in my undergrad they were reductionist in their thinking. From a systems perspective, it seems reasonable to think salt concentrations will continue to change in different places. For all we know, as freshwater redistributes with melting over here, and increased rain over there, and increased evaporation in this other place, maybe new areas will start to see the formation of more-dense-than-average water, and that water will sink…. In other words, as we turn off “bottom water factories” near Anarctica, maybe we are slowly turning on others! Do we know enough to know we know the answer? This layman doesn’t know, but I doubt it. If new places for bottom-water formation take over from the Antarctic coast, its equally possible the Gulf Stream could continue full force, just with a somewhat – or a radically – altered pattern. All speculative but one thing should be clear – we can’t change the way this massive energy input (heating of tropical surface waters) is distributed around the earth without busting our paradigm. And the new equilibrium will likely be reached via fits and splutters as the system hiccups its way to that new normal. This process will take a long time, so my main concern for humans is whether the world’s agricultural regions can keep producing the foods needed for our growing pop despite all the temp/precip extremes the fits and splutters will bring about. If we’ve got current science that answers some of these questions/ideas, I hope the promised future RC post will address them.

  24. 74
  25. 75
    Mark Conder says:

    Report: Global warming didn’t cause big US drought

    “Other scientists have linked recent changes in the jet stream to shrinking Arctic sea ice, but Hoerling and study co-author Richard Seager of Columbia University said those global warming connections are not valid.”

  26. 76
    Hank Roberts says:

    “This was natural variability exacerbated by global warming,” Trenberth said in an email. “That is true of all such events from the Russian heat wave of 2010, to the drought and heat waves in Australia.”

  27. 77
    Dan says:

    re: 75.
    You conveniently left out:
    “Another scientist though, blasted the report.

    Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research, a federally funded university-run research center, said the report didn’t take into account the lack of snowfall in the Rockies the previous winter and how that affected overall moisture in the air. Nor did the study look at the how global warming exacerbated the high pressure system that kept the jet stream north and the rainfall away, he said.

    “This was natural variability exacerbated by global warming,” Trenberth said in an email. “That is true of all such events from the Russian heat wave of 2010, to the drought and heat waves in Australia.””

  28. 78
    Radge Havers says:

    More movies:
    Do the Math screenings

  29. 79
    Mark Conder says:

    Dan@77 wrote “You conveniently left out:”

    On the contrary, I just quoted the part of the article which I thought contained the primary controversial statement. I think his conclusion that the drought was a “random event” is likely erroneous, but I am not an expert in the field.

  30. 80
    Hank Roberts says:

    I take back what I said about geologists, I was wrong:

    “… One of the speakers told us about placements their organisation (Geology for Global Development ( ) coordinates help scientists learn about social and ethical issues and how they relate to their research.”

  31. 81
    David B. Benson says:

    Since the SWITCH thread is now closed to further comments, those wishing to continue might choose to do so on the BNC Discussion Forum which is post facto moderated. There are several threads to choose from, but since Amory Lovins was mentioned in some of the comments, Critique of Lovins book ‘Reinventing Fire’
    is an appropriate one.

  32. 82
    David B. Benson says:

    Warmest Summers in Last Two Decades in Northern Latitudes Were Unprecedented in Six Centuries
    so I suppose the proxies only went back that far?

  33. 83
    Chuck Hughes says:

    Climate Change can be solved according to Peter Byck if you look at his movie:

    Click the button below for a link to a fascinating study by Rebecca Ryals and Whendee L. Silver of UC Berkeley, Department of Environmental Science, Policy and Management, published in ESA Journal, about the carbon sequestration potential of grasslands.

    Is this more wishful thinking or is there more to this idea? This was featured on “Real Time with Bill Maher” tonight. I don’t know if anyone happened to see this or not but if you did see it, what’s your take on this as a possible solution or viable idea?

  34. 84
    David B. Benson says:

    Chuck Hughes @83 — Button below? Anyway, I’m skeptical about grasslands doing anywhere near enough. For the reasons, read Irrigated afforestation of the Sahara and Australian Outback to end global warming

  35. 85
    Hank Roberts says:

    I’m not skeptical about grasslands; I can see grassland propagation being a powerful restoration tool.

    I started doing restoration with native grasses over 20 years ago, collecting seed where I found them on a damaged site, farming them through a few generations to increase the seed quantity, and reseeding on the site (a burnt-over mountainside that had lost a foot of topsoil in the past century and had about 3/8″ left, according to one hydrologist who looked the place over with me and some field botanists interested in restoration).

    What I learned is that nature did a better job of reseeding — the ‘farmed’ seed increase worked, but the seed bank in the soil that remained and the seeds from the plants on the site survived better.

    The main effort turned out to be discouraging the fast-growing annual invasive grasses the first couple of years after the fire — the Asian and European annuals produce a flat shallow broad mat of roots just under the surface that intercepts every drop of dew and captures the flush of minerals in the ash the year after the fire. But the invasive annuals are susceptible to discouragement — the trick for my site seems to be to keep them discouraged while the native perennial grasses, with a very different growth habit, get reestablished (the native perennials make deep roots first, and only begin to shade the ground around them after several years. If they get the chance to do that, they can compete with the invasives.

    Discouraging invasives is tough — takes timing and luck. I tried flame weeding (‘blanching’ with a propane torch). Works great if you can be on the site right after a rainfall, at the right time of the year so the annuals have already spent their effort making seed but the seed isn’t ripe yet; wave a hot torch over the area, they turn bright green as cell walls burst, release a puff of steam — and a few hours later they fall over. Done too early, they just make more shoots and seeds; done too late, they love the fire (they’re fire-adapted) and the steam pressure shoots ripe seeds in all directions around where the fire’s burning so half of them drop onto already cooling blackened surfaces where they have no competition.

    I tried feeding the soil microbes right after fires with sugar, learned that off Usenet from biologists — the invasive annuals as I said prosper right after a fire, benefiting from the flush of minerals in ash. The deep rooted perennials don’t capture that well unless the water soaks in; on a fire-damaged site runoff is the big problem. So spraying a saturated sugar water solution over the site before the first winter after it burned — so the available carbohydrate is there along with the minerals and ash — is a trick to get the soil microbes very active; they consume the sugar and the minerals and build soil; the native grasses work with that, while the annual fire-loving invasives get starved. That works better.

    This ain’t easy. But it’s a heck of a lot faster than planting trees, and a perennial native understory favors tree regrowth (while accumulated fuel from invasive annuals favors annual fires).

    Just my experience. Other sites, other results. But — look at the deep paleo work — look at when and where grasses evolved. They’re a force on climate.

    The perennials that made the tallgrass prairie did a good job. (The site I’m working on was, in the 1800s, tall grass between tall trees, the descriptions are of riding on horseback with grasses taller than the horses’ bellies. I’ve got a few pockets where the perennials that grow for decades to a century are coming back and they do indeed get that high. They make dirt, real well.

    Yeah, you can grow trees. But you can grow trees better if they’ve got a multistory shaded canopy and are growing among smaller plants that are already building soil, and that can burn cool and gracefully every decade or so in a way that clears out the fuels between the larger trees. That’s the trick.

    It’s a 200 year project kind of thing.

  36. 86
    Doug Schaefer says:

    The “button below” should be the link to the article

    If you haven’t journal access, it is always possible to email the corresponding author for a copy.

  37. 87
    Martin Vermeer says:

    David B. Benson #82:

    so I suppose the proxies only went back that far?

    Don’t think so: This article goes 2000 years back.

    It was really a bit warmer that far back in the high North. Think Milankovich.

  38. 88
    Hank Roberts says:

    > ESA journals … grasslands

    Hm, it’s a compost article: ” a single application of composted organic matter can significantly increase grassland C storage, and that effects of a single application are likely to carry over in time.”

    But why compost? What part of the compost is being used and by what organism?

    Compost can mean many things, depending on the source.

    “… sludge companies are allowed to take the sludge left behind in wastewater treatment plants, bag it, and sell it as an organic amendment found in garden centers and big-box stores ….” — Rodale

    There’s no end to the ways that toxic waste gets recharacterized as fertilizer, under US rules at least. Until there’s a body count and a proof of harm, once something’s recharacterized as useful, it’s pre-approved. NYT: No prior safety test done on most new chemicals before they’re sold for most purposes. Where do they end up? Sewage sludge.

  39. 89
    Hank Roberts says:

    Oh and remember that great ’60s slogan “the solution to pollution is dilution”?

    They’re still doing that:

  40. 90

    Arghh! someone should tell National Geographic “Titanic case closed” (Now playing on NGS channel) that the science about the reason of Titanic collision is wrongly explained, that this very science of refraction has huge implications over complementing remote sensing data gathering and the study of the sea to air interface.

    OK Titanic collision weather conditions were such that a refraction “water wall” hiding the Iceberg was impossible. A “water wall” mirage hiding a tall iceberg against the star horizon is extremely rare, if not cant be higher than a 68 meter above sea level iceberg a quarter of a mile away. Luckily, this poorly explained science gives a wider insight, opens the door to the science of horizontal refraction. Its complex yet simple at once,
    if the air temperature is greater than open sea water, the horizon rises slightly, because sea water does not have the same thermal properties of pack or sea ice, it doesn’t cool fast like the land in a starry night . If air temperature at collision was colder than water (as the data suggests) the mirage created would be an inferior mirage, making the iceberg look bigger than it is!

    So for those tired about Titanic discussions, take another look, the reason of its sinking was arrogance (like thinking us humans have nothing to do with GW), going fast in known ice fields, was incompetence rewarded by disaster. Explaining it otherwise, as NGS tries to do, is blessed by revealing a facet in science rich with methods
    in unraveling the demise os Sea ice.

  41. 91
    Hank Roberts says:

    An increase in crevasse extent, West Greenland: Hydrologic implications
    published online: 16 SEP 2011
    DOI: 10.1029/2011GL048491

    “…the area occupied by crevasses >2 m wide significantly increased (13 ± 4%) over the 24-year period. This increase consists of an expansion of existing crevasse fields, and is accompanied by widespread changes in crevasse orientation (up to 45°)…. We provide a first-order demonstration that moulin-type drainage is more efficient in transferring meltwater fluctuations to the subglacial system than crevasse-type drainage. As enhanced basal sliding is associated with meltwater “pulses”, an increase in crevasse extent can therefore be expected to result in a net decrease in basal sliding sensitivity. An increase in crevasse extent may also accelerate cryo-hydrologic warming and enhance surface ablation.”

  42. 92
    Chris Dudley says:

    While it is good that nuclear power is back on the OT list, it should be remarked, given the recent discussion, that in the first quarter of 2013, Portugal’s electricity was 70% from renewable sources. This clear example counters tired but oft repeated arguments against renewable energy displacing all other electricity generation methods.

  43. 93

    #92–A dramatic example. The Danish experience had already shown that renewable use can indeed reduce total fossil fuel use, but these numbers are quite a bit more impressive. And there’s lots of potential in their case for an expansion of solar PV, which ought to afford them some diversity as a hedge against weather patterns getting ‘stuck’ in an unfavorable mode for power generation. (Dry but windless, in their case.)

  44. 94
    David B. Benson says:

    Chris Dudley & Kevin McKinney — Lets keep all generating energy matters OT here on Real Climate, please. This is a poor forum for that purpose. I’ll break my own rule by pointing out how unexceptional Portugal is:


  45. 95
    sidd says:

    1)if deep ocean mixing time is 1e2 to 1e3 yr then deep ocean C13/C12 ratio reflects preindustrial atmospheric composition
    2)as deep ocean upwells it releases CO2 upon warming to surface temperature, with different C13/C12 ratio than present day atmosphere
    3)Is this detectable as a measure of deep ocean return times ?


  46. 96
    Hank Roberts says:

    > Sidd, deep ocean mixing

    too many “if” variable there for “is this detectable” to be a simple answer.
    They use C14.

  47. 97

    #94–That suggestion never quite seems to work out, somehow, though I’m not without sympathy for the idea.

    I’ll just say that, while it’s nice to see that Washington state does indeed have a Whole Lotta Hydro goin’ on, I think maybe you yawned too soon. Just my perspective…

  48. 98
    Chris Dudley says:

    Congratulations to Inside Climate News for winning a Pulitzer Prize.

    Now that the prize is being awarded to non-profits, perhaps realclimate will be next. (Just don’t ignore me when I point out that a reference is incorrectly cited. )

  49. 99

    sidd, the heat diffusion math straightforwardly matches what is observed:

    No reason to overthink it.

  50. 100
    David B. Benson says:

    WebHubTelescope @99 — Very nicely done in that link.