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Comments 51001 to 51050:

  1. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    This is the old "more stuff in the way" argument. There are a variety of metrics you can use to measure this and Tom has pointed out a couple. There are lots more and if anybody would have a real interest in figuring it out, the global insurance industry certainly does. Google Munich RE for what a big reinsurance company thinks.
  2. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    Agnostic, I acknowledge that the issue of fugitive emissions from shale-gas operations is not yet settled and that in some instances there may well be significant gas leaks. As far as I can tell, contra to your link, the apparently leaky gas fields in Queensland are coal-bed methane fields, which are typically shallower than shale gas fields and are not artificially fracked. Not that the climate system cares where the methane comes from... One source of GHG emissions from some shale-gas operations that is incontrovertible is the deliberate venting of carbon dioxide from some fields after it has been separated out from the produced methane to make it saleable. For example, in some shale-gas fields in British Columbia, the produced gas contains 11% CO2. It would be relatively cheap to sequester this gas (much of the cost of CCS is the separation cost, which is already sunk in this case), but this has not been mandated by the provincial government.
  3. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Further to Magnus and Tom, maybe as so often is the case "it depends," in this case on what we mean by "our society." If you live in Norway it's reasonable to suppose 10m would not effectively collapse society. For Bangladesh a different story; most of Bangladesh is below 10m, with the capital Dhaka at 4m. It's hard to imagine most of the ~150M population of Bangladesh making a move to the <20% of the country left dry by a 10m rise in sea level and in any case they'd be confronted with the problem of what to eat after virtually their entire inventory of arable land was lost. There are a number of other countries in the world that live in a similar "deltaic mode."
  4. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Tom Curtis @6 "Or perhaps there just are some people who will say anything to avoid actually thinking about the data." Actually, I've thought about the data, closely: https://sites.google.com/site/climateadj/home/noreast-pdi There's no evidence that Sandy like storms are the new normal. We are in a period of high activity which is the old normal. God forbid if the 1869 hurricane season repeated itself, with the storm tracks a couple of hundred miles south. There's a name for people who refuse to look dispassionately at the data. It starts with an "a".
  5. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    I should note, with regard to Magnus claims (@4), even a 10 meter sea level rise would not, by itself, be enough to cause the collapse of our society, or even significantly impoverish us. In particular regions, sea level rise is likely to be devastating in terms of lives lost and financial costs, but primarily by worsening the impacts of storm surges. A very small percentage of the total land surface will be lost to inundation. Consequently, except in low lying deltas, the cost of adaption will be met simply by moving major cities about a kilometer inland - something certainly within our economic ability.
  6. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    chriskoz @8, I think you are completely correct on this. A 5 meter sea level rise per century would be equivalent to melting a third of the combined West Antarctic Ice Sheet (WAIS) and the Greenland Ice Sheet (GIS) within a 100 years, which is IMO not credible. Hansens formula of 1 mm of sea level rise in 2005-2015, doubling every ten years results in the complete melting of all ice sheets by 2175, a 70+ meter sea level rise in under two centuries. Plainly the doubling time (if it exists at all) must terminate rather quickly, and is very likely to do so at, or less than, the Heinrich event rate. Being fair to Hansen, his point appears to be, not that sea levels will rise by five meters in this century, but that far more rapid rises than is allowed for by linear increases are possible, so that the likely rise is significantly above linear projections. He may be right in that. I would not exclude a two meter rise, although I believe the 1 to 1.2 meter range to be far more plausible.
  7. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Thanks DB for the link to Hansen 2012. The claim therein, of exponential, 7y doubling, IS desintegration is from the curve fitting to GRACE data, as seen on its Figures 8a-d. With such curve fitting, it finds the SLR as high as 5m by 2100 possible. I find the practice of such curve fitting questionable. Especially, if it arives at the improbable conclusion of dSLR 50mky-1 (5mcentury-1), not seen in last 1500ky, far in excess of Heinrich events. On top of that, it must be remembered that strong negative feedbacks on melting rates do exists, like ice flow rates and cooling of the upper ocean. And there is simply not enough ice (far less than the emount of Laurentide IS than triggered Heinrich events) to sustain the exponential rate. So Rahmstorf 2007, being a conservative, semi-empirical linear model, concluding 1m SLR in 2100 is more realistic.
  8. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Michael, a term search for "Arctic" on her publications list turns up 54 hits. Those hits will include the 2 hits for "Antarctic". Clearly the majority of her polar related research has been related to the Arctic rather than the Antarctic. A search for "Ice" turns up 49 hits. I gather she has researched the meteorology of the Arctic, including ice formation in clouds more so than sea ice extent. "Sea ice" returns only 21 hits.
  9. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    Doug H A number of Papers have been published recently on fugitive emissions of natural gas, variously estimating them at between 2%-5% of total production. There are indications in Australia that fracking may result in much higher emissions, though it is unclear if these are from the ground above the fracked area or the well head area. Andy S notes that … leakage and other environmental consequences of fracking have been exaggerated … However, preliminary (non peer reviewed) research undertaken by the Southern Cross University in Queensland indicates that methane concentration in the atmosphere above areas where fracking gas mining has occurred are around 3 times higher than the global average. http://www.istockanalyst.com/business/news/6155419/fracking-blamed-for-methane-releases As pointed out by scaddenp significant venting of methane also occurs during coal mining. With introduction of the carbon tax, it is expected that several of the most “gaseous” mines in Australia will find it is no longer economic to continue operating and will close.
  10. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    KR, I read Curries publications back to 2007 and saw one paper on Antarctic sea ice. Can you suggest what years she published anything on arctic sea ice? I know she has several blog posts on sea ice but I do not count them. Her web page calls her an atmospheric scientist and her papers mostly talk about the atmosphere.
  11. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    Andy S@5: Your link does not work for me, in Google Chrome.
    Moderator Response: [AS] Thanks, fixed!
  12. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    chriskoz@2 Thank you. My opinion is that the leakage and other environmental consequences of fracking have been exaggerated by some environmental activists. There are leaks and other negative consequences from fracking, of course, but many of these problems can be mitigated with stringent regulation. I think that natural gas, shale gas included, can be beneficial in reducing GHG emissions in the short term, especially if it displaces much more damaging coal . However, most of the gas is going to have to stay in the ground if we want to avoid a climate catastrophe, so I am opposed to new fossil fuel developments of any kind so long as they don't pay their way through a carbon tax and compensation for their other environmental impacts. My opinions on shale gas development are broadly consistent with the view of this report by the Pembina Institute, which was funded by the David Suzuki Foundation.
  13. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    Doug@1: You are probably correct that most fugitive methane comes from gas production (and also gas storage and transportation), at least that's what the EPA says for US sources. Note that the numbers in the EPA table are CO2 equivalents not the weight of methane, so they need to be divided by 21 [edited] to compare them to the numbers mentioned in the article. Significant amounts of methane comes from oil and (as Phil Scadden said) coal production, as well. I have a hunch that oil production in countries that have less stringent engineering and regulatory standards that the US quite likely vents proportionally more methane than the US, but I don't have a reference for that. There's also a very comprehensive EPA report on natural sources of methane, although it does seem (to me) to downplay permafrost methane emissions, at least in the light of recent permafrost research. I'll maybe add these links to the main article.
  14. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    climateadj @4. Your right. And the the assets in California are increasingly "sky high" as well, which no doubt accounts for the increasing number (not cost, but number) of geophysical disasters in North America: Oh sorry, there is no noticable increase in geophysical disasters, but meteorological, hydrological and climatological disasters are going through the roof. And, of course, assets in the mid-west must also be "sky high" to account for the surge in thunder storm damage: Or perhaps there just are some people who will say anything to avoid actually thinking about the data. What do we call them, now. I think it starts with a "d" ....
  15. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    chris - mining coal leaks CH4 something terrible too.
  16. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    Indeed jackdale, no Lindzen, Spencer, Christy, Curry, etc.
  17. 2012 SkS Bi-Weekly News Roundup #7
    Atrocious comment stream at NYT today. Article is on Doha: "Ignoring Planetary Peril, a Profound ‘Disconnect’ Between Science and Doha."
  18. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    michael sweet - "Curry is an Atmospheric scientist and has not published any papers on Arctic sea ice extent" Actually, Judith Currys publications list includes a great deal on Arctic and Antarctic ice. Which makes it even more puzzling that her major recent contributions to the discussion appear limited to handwaving about "uncertainty monsters" and throwing her support behind 'skeptic' arguments and myths - she should certainly know better from her own work.
  19. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    daba@39 It interesting who did not sign it; Curry and Spencer being the most conspicuous. I assume that would have been asked.
  20. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Of course the storm related insurance claims are "going to just keep coming". The value of assets along the coast are increasingly "sky-high".
  21. DIY climate science: The Instrumental Temperature Record
    @Kevin C Incredible job Kevin congratulations, it is a very usefull aplication , only a little obsevation , the graph generated only goes to 2005 ? Why? exist some reason to no show the last six to seven years? I think it would be appropiate for the generated graph to the last data was available, if not, the fake skeptics can accuse us (hey are hiding the last year "cooling")or (you are "cherripik" the data) We should follow the example given from this web, always trying to use (all available data) and not just a part, although that part is most.
  22. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Otto, It is true that Dr. Box specializes in ice changes and insurance rates only rely on an unbiased evaluation of how much damage occurs. We would be much better off at WUWT where the commentators (like the host) often have no science degrees at all. This Skeptical Science post (among many found by searching "extreme weather" quantitates extreme heat and shows that the extreme heat (and associated drought) in the American Midwest this year is 98% likely caused by global warming. That's a quick $50 billion damage in the US alone. AGW added almost a foot of sea level rise before Sandy. the damage caused by the last foot of the flood is entirely caused by AGW. Recently the Dutch Government wanted to have a discussion of Climate related problems. The first topic was Arctic Sea Ice collapse. See this RealClimate link for details. They used Judith Curry for the skeptic voice. Curry is an Atmospheric scientist and has not published any papers on Arctic sea ice extent. Presumably no actual ice experts were willing to provide a skeptic voice. Why don't you go over to that blog and post your objections to using Dr Curry since she is not an expert on Sea Ice Extent.
  23. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Chriskoz - see the text under that heading. A long time perhaps by human time scales, but a blink of an eye in a geological sense.
  24. Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    Interesting article Andy, I cannot wait for the next part. I have a feeling that recent 2012 reduction in US CO2 emissions (sadly more than offset by increases in the rest of the world, China, India), if coming from from a large switch from coal-based to gas-based fuels, may be misguided, if said gas comes from fracking. Fracking leaks CH4 and I'm even not sure if we can quantify the amount of leakage (surely the recent CH4 increase must be coming from those, let's hope they are not from permafrost melt) so I'm not that positive about those emission reductions. Needless to say the environmental destruction of fracking which is OT here. I think burning coal through high efficiency gasification process might be lesser evil rather than gasifying it "in situ" through fracking. Hansen says we must leave coal in place, deniers may say "we are not exploiting coal, just gas through fracking" but they de facto exploit coal, even further, they are destroying the emvironment in the process.
  25. Doug Hutcheson at 18:17 PM on 9 December 2012
    Subcap Methane Feedbacks. Part 2: Quantifying fossil methane seepage in Alaska and the Arctic
    human-mediated fugitive emissions associated with fossil-fuel energy production ... amount to about 100 Tg CH4 per year
    Cheerful thought. I wonder how much of this comes from fracking and gas production and how much from oil production? My guess would be that gas would be by far the greatest source, giving little comfort to areas currently under gas exploration licences here in Australia and around the globe. What percentage of gas is lost to fugitive emissions, anyone know?
  26. Doug Hutcheson at 17:59 PM on 9 December 2012
    Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Otto1 @ 1 , no-one is saying "climate change is responsible for extreme weather events" like Sandy. To quote from the OP,
    Climate change, Box says, “shifted the odds in its favor” and made its impact more severe as a result of the warmer sea temperatures along the eastern seaboard … and the resulting higher sea levels resulting from those higher temperatures.
    Get it? Shifted the odds. Made the result worse than it might have been. Didn't cause it.
  27. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Paul Magnus@4 you said:
    So the rate is exponential as Jim Hansen has frequently pointed out and the data is indicating. ie a doubling every 7yrs at the moment
    Can you give the source of your claim (if Hansen, then full text is available in which I'm very interested). IMO, the dSLR acceleration cannot be that fast: we are already melting very fast: 35my-1, which is just 4-6 times slower than Heinrich events as seen on figure 1. So we've just 2 of those "doubling every 7yrs" before we reach a desintegration of Heinrich proportions. I'm not saying Heinrich on top of Holocene optimum won't happen but that it cannot happen so fast. Perhaps we will see a doubling of dSLR in this century, perhaps the second dubling later at the end of this century (most of us will not live up to this, only our children). IS response is a slow but sure process in today's state of climate. No one was able to quantify it to date let alone predict "doubling of dSLR every 7yrs"... The section title "Sea Level Rise Closely Follows Polar Warming" is very intriguing but left unquantified: did anyone heard "how closely"? 100y or 500y?
    Moderator Response: [DB] This Hansen publication is likely the source. An accessible version containing the full submitted text is here.
  28. Doug Hutcheson at 17:41 PM on 9 December 2012
    It's El Niño
    In spite of the volume of Bob Tisdale's comments, I still don't see how he accounts for the TOA energy imbalance. More energy is arriving than leaving: how does his hypothesis account for that?
  29. Newest Yale Forum Video: A ‘Play-by-Play’ on Sandy with Kerry Emanuel
    Color me unimpressed. There is no empirical evidence that climate change is responsible for extreme weather events like hurricanes and superstorms like Sandy. Jason Box's specialty appears to be the Greenland ice sheet, not exactly relevant. And Joe Scarborough pointing to a discussion he had recently had with a man who handles insurance rate tables? Like, wow.
  30. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    jackdale @38 - it really doesn't seem like it. They were clearly going for quantity over quality in the letter signatories, similar to the Oregon Petition. They try to get big numbers on these lists, but to do that you need to have really low standards, because nobody who knows anything about climate would sign such utter nonsense.
  31. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    Did Tom Harris actually vet those who signed the letter? One was banned from WUWT for carpet bombing the site with his nutty views of the sun. (Watt's words, not mine). But as someone who worked with children for all of his professional career, I find this person's past to be rather unsavoury. (That is a meiosis.)
  32. DIY climate science: The Instrumental Temperature Record
    A very impressive accomplishment! Folks here who are (or know) science teachers should do everything they can to see that science students get their hands on this app. Hand some bright young students this ball and see where they run with it. There are so many ways to "slice and dice" temperature data with this "killer app" that it could be the foundation of countless science projects. Now for some perspective, and something that people should tell "skeptics" (and tell them again, and again, and again -- then then tell them once more for good measure): Kevin C has accomplished in a few months what Anthony Watts and his numerous "surfacestations" followers haven't been able to accomplish in over half a decade -- not only has Kevin actually crunched the temperature data and validated the NASA/NOAA/CRU results that Watts and Co. have only sniped at, he has put together a polished, easy-to-use app that lets anyone else do the same. Compare that with what Watts and Co. have failed to accomplish in all their years of "scrutinizing" the global temperature record. And Kevin managed to do all this without filing a single FOI request! Imagine that. The only thing that Kevin's software package is missing is a catchy name. Maybe something like "WattsBuster Professional". Or even "WattsBuster Ultimate" (sorry, Microsoft). Anyway, I've been working a bit on my own global-temperature project (it's not nearly as polished and professional as Kevin's), but it shows another interesting way to demonstrate the robustness of the global temperature station network. I took my own global-temperature code and put a Google Map front-end on it (based on html/javascript kindly supplied by Nick Stokes -- thanks, Nick!). Users can "roll their own" global average temperature results by clicking on stations on a Google Map display and watch the results get updated each time they click on a new station. It's really quite amazing how few stations you need to replicate the NASA/NOAA/CRU global warming trends. (Just a few dozen scattered around the world). I went and rolled everything up into a virtual-machine appliance file. To use it, all you have to do is import the appliance file into the VirtualBox virtualizer and fire it up (very easy -- just a few mouse clicks will do it all). VirtualBox is available at www.virtualbox.org and will run on all newer Windows/Mac/Linux platforms. It is very easy to install and use with pre-built appliance files (like mine). I present the results in two plots: The first plot (upper plot in the display output) shows the global temperature results that my app computes from both raw and homogenized data, along with the official NASA/GISS "meteorological stations" results for comparison purposes. (My raw results are shown in red, my adjusted results in green, and the official NASA/GISS resuts in blue). The second plot (lower plot in the panel) shows how many of the stations selected by the user actually reported data for any given year. (Station counts can be fractional -- if a station reports data for 6 months of a given year, I count it as "half a station"). This way, users can correlate the quality of the temperature results for any given time period with the number of stations that actually reported data for that time period). Folks who want to try out the global-temperature virtual machine can get it here. It's rather a pig of a download (about 1GB), but it encapsulates an entire operating system. Plus, you need to download and install the VirtualBox app and then import the appliance file into it. But it's all quite easy, provided that you have the bandwidth and/or patience to download the virtual-machine file. You will want to have at least 1GB memory on your system. 2 GB or more is desirable -- but 1 GB will work just fine if you make sure that you don't have any other memory-hogging apps running. I chose this virtualization approach because virtualization lets you nail down all the configuration details in a completely automated "start it and let it run" package that will run on almost any popular operating system. Think of virtualization as a "sledgehammer approach" to cross-platform compatibility. To summarize: 1) Download/install VirtualBox (virtualbox.org). 2) Import the global-temperature appliance file into VirtualBox (just a few mouse clicks). 3) Hit the VirtualBox "Start" button and wait for the virtual machine to boot up. 4) Start "rolling your own" global temperature results by clicking on GHCN station icons. That's it. Note: This is just a side "hobby project" of mine, so there are some not-fully-implemented features and other random loose ends that need to be sewn up (but it still works well enough to be a useful educational/demo tool). IOW, YMMV. And finally here's a screen-shot of the global-temperature virtual-machine in action .
  33. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Thanks Rob... This with the increase in the rate of rise just reported, the known uneveness of sea level, particularly affecting the Eastern USA, NASA's recent sea level rise report (expect 2m by 2100 globally, that is a little more New York of course), increased Hurricane storm surges, and it seems inevitable that New York does need relocating and Florida in the next 50-100years and with the rate warming accelerating and this being at the fastest ever noted in geological time along with the record impulse of CO2 and SO2 cooling about to be lost, and it does beg the question what on earth are we doing? Its not like there is a spaceship that can take us away anywhere sensible and if divine intervention is coming they are cutting it fine! Yet all that is discussed is reducing emissions slowly, and spending billions of extra tonnes of carbon to keep the lights on by putting up so called low carbon renewables and their infra-structures (also totally dismissing the other environemntal impacts associated with them in clinging onto the power green bullet), to provide fresh water security with de-salination plants, to build huge sea defences that will be futile in less than 50years, fighting senseless wars, to grow addictive cash and fuel crops, to pull down forests, to, to ,to, to, to, to charging billion of mobile phones toxic waste batteries. Where do you put Floridians and New Yorkers? West Scotland isn't that populated, Greenland? There will be new land here as well, that will emerge from the localised falling of sea levels there as the ice sheet shrinks. Well if we can put a man on the moon surely we work that out? Maybe the military arround would do a better service for their nations by working on these sorts of problems rather than killing people pointlessly??? Like how to abruptly stop using fossil fuels?? Isn't humankind mature enough yet to just stop fighting and realise than more is acheived by working together rather than in violent opposition to each other, well apart from progressing weapons development that is. How much carbon does the arms industry use? And how environmentally toxic is it? Anyway back to reality, worsening weather, middle east turmoil, rapid ice melt, CO2 emissions growing, more oil being mined, arms industry growth, economic fraility, biodiversity devastation, willingly making toxic materials, extreme inequalities, politicians happily gambling on 50:50 odds of an end of the world situation, highest emissions ever, permafrost tipped already, arctic amplification in severe feedback mode, and all with a dose of a total apparent lack of realisation of the actual scale of this problem. How many people in Bangladesh are needing to move? Mid / South USA dessert refugees? And so on and so forth. How much more carbon can be afforded? Peak CO2... 450ppm, scarey! 425ppm.....too worrying 400ppm...still need to move New York and Florida. 350ppm...the carbon debt, still give greater than 5% of 1.5C-2C, so New York and Florida still need to move. Therefore how much more carbon are people theoretically prepared risk? How tight is the carbon budget? ????
  34. It's El Niño
    "We will see if Bob returns......" Well, he did...after a fashion, saying many words, and answering few questions. Kevin C, stunning work! This entire thread has been most illuminating and educational.
  35. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    So heres the twist... "Considering that humans have been warming the climate for several centuries, a more significant finding was the short time lag between warming at the poles (as shown in the ice cores), and the response of sea level rise - which implies the disintegration of the ice sheets. In the case of Antarctica, large ice reductions occur within 400-700 years, and for Greenland, ice reductions occur very quickly - within 100 years." sea level history suggests we should expect much higher rates of sea level rise in the future." That last sentence should read near future. ie next 10 - 50 yrs. ie the rate is around 1.5m per century, but we have be heating up relatively rapidly for the last 50yrs or so. So the majority of the 1.5m rise is going to happen in the trailing part of the 100yrs. So the rate is exponential as Jim Hansen has frequently pointed out and the data is indicating. ie a doubling every 7yrs at the moment. So collapse of our society as we know it is inevitable and just around the corner, even from Only a SLR perspective!
  36. It's El Niño
    In my opinion, neither the OP nor Bob Tisdale provides an adequate explanation of ENSO. For an up-to-date and authoritative description of ENSO, see: El Niño and Southern Oscillation (ENSO): A Review by Chunzai Wang, Clara Deser, Jin-Yi Yu, Pedro DiNezio, and Amy Clement. Chunzai Wang , NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida Clara Dresser, National Center for Atmospheric Research, Boulder, Colorado Jin-Yi Yu, University of California at Irvine Pedro DiNezio, International Pacific Research Center, University of Hawaii Amy Clement, School of Marine and Atmospheric Science, University of Miami Abstract The ENSO observing system in the tropical Pacific plays an important role in monitoring ENSO and helping improve the understanding and prediction of ENSO. Occurrence of ENSO has been explained as either a self-sustained and naturally oscillatory mode of the coupled ocean- atmosphere system or a stable mode triggered by stochastic forcing. In either case, ENSO involves the positive ocean-atmosphere feedback hypothesized by Bjerknes. After an El Niño reaches its mature phase, negative feedbacks are required to terminate growth of the mature El Niño anomalies in the central and eastern Pacific. Four negative feedbacks have been proposed: reflected Kelvin waves at the ocean western boundary, a discharge process due to Sverdrup transport, western Pacific wind-forced Kelvin waves, and anomalous zonal advections. These negative feedbacks may work together for terminating El Niño, with their relative importance varying with time. Because of different locations of maximum SST anomalies and associated atmospheric heating, El Niño events are classified as eastern and central Pacific warming events. The identification of two distinct types of El Niño offers a new way to examine global impacts of El Niño and to consider how El Niño may respond and feedback to a changing climate. In addition to interannual variations associated with ENSO, the tropical Pacific SSTs also fluctuate on longer timescales. The patterns of Pacific Decadal Variability (PDV) are very similar to those of ENSO. When SST anomalies are positive in the tropical eastern Pacific, they are negative to the west and over the central North and South Pacific, and positive over the tropical Indian Ocean and northeastern portions of the high-latitude Pacific Ocean. Many mechanisms have been proposed for explaining PDV. Changes in ENSO under global warming are uncertain. Increasing greenhouse gases changes the mean states in the tropical Pacific which in turn induce ENSO changes. Due to the fact that the change in mean tropical condition under global warming is quite uncertain even during the past few decades, it is hard to say whether ENSO is going to intensify or weaken, but it is very likely that ENSO will not disappear in the future. Particularly germane to the recent dialogue between Bob Tisdale and others on this comment thread are the two sentences that I have bolded in the above Abstract.
  37. DIY climate science: The Instrumental Temperature Record
    Thanks for the comments. Doug: I've fixed the article text, John will have to do the page title. Dawei: I look forward to seeing what you've got. If you don't already have an image host, I find imgur.com good. DSL: I think Watts' station ratings are USHCN only. I did as an exercise manage to do a reasonable reconstruction from 60 well spaced stations in a spreadsheet, I may be able to dig that out if you're interested. Nick: I'll deal with the trend line and the colours. I suspect frames will break the content management system though. You could pop the printable version of the article (link at the bottom of the article) up in a separate, non-maximised window. Thanks! I'll do the changes in a week or so to try and deal with any other issues which come up. I've also converted the ERSST v3b data to Hadley format so you can use it. If anyone wants to try it I could stick it on filedropper.
  38. It's El Niño
    Bob Tisdale places great weight on “teleconnection” processes throughout his numerous posts. It is therefore critical for all involved in this discussion to have a common understanding of what “teleconnection” is. According to the IPCC, Teleconnection: A connection between climate variations over widely separated parts of the world. In physical terms, teleconnections are often a consequence of large-scale wave motions, whereby energy is transferred from source regions along preferred paths in the atmosphere. Source: Annex I (Glossary) to Climate Change 2007: Working Group I: The Physical Science Basis, IPCC Fourth Assessment Report. In comment #159, Tisdale asks HH: “On the other hand, are you aware of teleconnections? Are you aware that there’s no heat transfer with teleconnections?” Is Tisdale assuming that there is a distinction between “heat” and “energy”, or does he employ a different definition of “teleconnection” than that stated above?
  39. It's El Niño
    The most recent replies from Tisdale are extremely verbose - and avoid addressing criticisms. Some notes from my point of view (not exhaustive, mind you, but if you find the first 10% of a Gish Gallop to be nonsense, you can reasonably expect the same quality in the rest): * Compo and Sardeshmukh 2009: Oceanic influences on recent continental warming - They found that running the models with oceanic warming (>93% of the energy from the GH effect) but without continental GHG warming (2.1% continental, 2.3% atmospheric) produced nearly identical model results to using full forcings. Tisdale claims this in some fashion invalidates ocean warming - but if you have only subtracted 5% of the forcing, leaving in 95% of the GHG effect, such results are entirely unsurprising. A nonsense claim from Tisdale. * And what of the more than sufficient warming from an enhanced greenhouse effect? And as I replied to KR at 134: Downward longwave radiation appears to do nothing more cause a little more evaporation from the ocean surface, which makes perfect sense since it only penetrates the top few millimeters. This statement alone represents pure denial on Tisdale's part. He has been pointed to the physics and to the observations confirming oceanic warming from the enhanced greenhouse effect - his response here is nothing more than a repeated, armwaving denial of the physics and the data. * Models. Kevin C has taken the time to examine Tisdale's model (single lag, no volcanic term - which, I will point out, Tisdale has never clearly explained), confirmed by replicating Tisdale's results. He has in addition examined the behavior of a more physically realistic two-lag model with volcanic forcing. When tested against data outside the training set, Tisdale's model fails completely. Kevin C's more realistic model replicates the data both within and outside the training set. Conclusions drawn from Tisdale's model are therefore unsupported. Tisdale's reply consists of just repeating his poor model results. That is no reply at all - Tisdale's model is a failure. * Tisdale claims that "global oceans did not respond proportionately" to ENSO events, but argues only from Sea Surface Temperatures (SST's). Not ocean heat content (OHC), but just surface temperatures. The energy involved in the ENSO is considerable in comparison to atmospheric energies, but not compared to the ocean mass itself. SST is by no means a sufficient measure of the global oceans - rather a noisy subset thereof. If you actually examine the global oceanic response you do indeed see a proportional response to forcing over the period of observations, with small variations occurring related to (among other things) the ENSO. Again, a nonsense claim from Tisdale, looking at the wrong data set relative to his hypothesis. --- Finally, after a Gish Gallop of (non)replies, Tisdale exits the thread. Leaving (IMO) questions unanswered, criticisms unaddressed, and multiple examples of denial of the physics and the evidence. At this point, after considering Tisdale's arguments, I would consider the myth of the ENSO driving global warming to be busted.
  40. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Shorter Andrew: For ice sheets, gravity is a bee-otch.
  41. Philippe Chantreau at 03:11 AM on 8 December 2012
    It's El Niño
    Bob Tisdale certainly makes a tremendous effort to have the last word, or the last couple of thousand words. I'm hoping that it will be examined closely, although I confess I do not have the leisure of doing so. I did notice this: "If the Rest-of-the-World sea surface temperature data cooled proportionally during the La Niña events of 1988/89 and 1998-2001..." The fact that they did not could certainly point to the existence of a warming forcing...
  42. Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    Yes.. Basically, when ice sheets grow, they appear to be limited by precipitation. Even if you have 2 meters of precipitation a year that all freezes, it would take 1000-2000 years to build a continental ice sheet. On the other hand, a back of the envelope calculation (direct sunlight, heavily absorbed) suggests that ice can melt at 10cm/day, or 36 meters per year. (36MJ/m2/day = 100kg ice/m2/day = 10cm) And ice dynamics/flow act to slow the growth of ice sheets and speed the melt. So a crude approximation suggests that meltdown should be much faster than freezeup..
  43. It's El Niño
    If nothing else is accomplished Bob at least lends new credence to the concept of "catastrophism."
  44. Pete Dunkelberg at 01:28 AM on 8 December 2012
    Past 150,000 Years of Sea Level History Suggests High Rates of Future Sea Level Rise
    It is interesting to compare this new paper with this Milankovich-based model: "So, we can see that [in this model] the Earth often pops rather suddenly into a warm interglacial state and cools a bit more slowly into a glacial state."
  45. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    It is obvious to most people that this denialist petition is nothing more than a publicity stunt prior to the United Nations Climate Change Conference in Doha. That said, I am surprised the denialists continue with the childish notion that an increase thermal energy immediately translates into greater temperature. As most people with a secondary school diploma already know, one calorie of heat is required to raise the temperature of one gram of water by one Celsius degree. These students also know that 80 calories are required to convert one gram of ice to one gram of liquid water. If the average global temperature has not increased as fast as century trend-line projections then you need only look for melting ice to locate the missing thermal energy. The arctic, which is melting at an unprecedented rate, is the likely culprit but what will happen to global temperature when all the ice has melted?
  46. It's El Niño
    A closing note: Thanks to all of you for your feedback. It does not appear we’re going anywhere with this discussion. That is, it’s quite obvious we are not going to agree about anything. Therefore, it’s likely I won’t be back on this thread
    That's one strategy to studiously avoid the meat of the criticism and instead hope that everyone will be overwhelmed by the spam, I suppose. In that veritable Gish Gallop of posts the only attempt to respond to Kevin C's devastating results was to insist they'd already be addressed by an earlier comment (#167). How disappointing. I suppose this stands as a warning to "skeptics" of the dangers of egging on SkS regulars to stop ignoring fringe theories and instead take a close look at them. You're better off staying below the radar.
  47. It's El Niño
    A closing note: Thanks to all of you for your feedback. It does not appear we’re going anywhere with this discussion. That is, it’s quite obvious we are not going to agree about anything. Therefore, it’s likely I won’t be back on this thread. And thank you, moderators. Enjoy your holidays.
  48. It's El Niño

    Michael Sweet says at 147: “Your claim here that Gavin Schmidt at Realclimate says you can compare a single realization (what happened) to the model average and not to the model envelope is simply untrue.”

    I don’t believe I claimed there “that Gavin Schmidt at Realclimate says you can compare a single realization (what happened) to the model average and not to the model envelope…”. I quoted Gavin Schmidt’s reply to the RealClimate comment at 30 Sep 2009 at 6:18 AM. It was:

    [Response: Any single realisation can be thought of as being made up of two components - a forced signal and a random realisation of the internal variability ('noise'). By definition the random component will uncorrelated across different realisations and when you average together many examples you get the forced component (i.e. the ensemble mean). Just as in weather forecasting, the forecast with the greatest skill turns out to be this ensemble mean. i.e. you do the least badly by not trying to forecast the 'noise'. This isn't necessarily cast in stone, but it is a good rule of thumb. - gavin]

    Gavin said what he said. He was not talking about model-data comparisons; he was talking about model outputs in general, as was the quote I provided you from NCAR. NCAR wrote:

    Unless you are interested in a particular ensemble member where the initial conditions make a difference in your work, averaging of several ensemble members will give you best representation of a scenario.

    I’m NOT interested in the model noise, Michael; I’m also NOT interested in a “particular ensemble member where the initial conditions make a difference in your work”; I’m interested in the forced component that’s presented by the multi-model ensemble mean of all of the CMIP3 or CMIP5 climate models in my model-data comparisons, because it gives you “the best representation of a scenario”.

    Note: The NCAR webpage I linked earlier seems to be offline, but the Wayback Machine has captured the text.

  49. It's El Niño

    Tom Curtis at 146 says: “Why did Tisdale include a La Nina dominated period in his final period, when he must know that doing so will distort the comparison with the earlier period? And if La Nina dominated periods cause cooling, why has there been no cooling in the La Nina dominated period from Jan 1999 to the present?”

    Tom, you’re referring to this graph. If you had been following the conversations on this thread you would have discovered that the global oceans did not respond proportionally to the La Niña events of 1988/89 and 1998-01 and that that failure to cool proportionally during those La Ninas was why the sea surface temperatures for the Atlantic-Indian-West Pacific oceans (referred to as the Rest-of-the-World in earlier comments) acquired its long-term warming trend. So why then are breaking the latest warming period at 1999 during the 1998-2001 La Nina when the Atlantic-Indian-West Pacific data acquires part of its long-term trend? If the Atlantic-Indian-West Pacific data cooled proportionally during the La Niña events of 1988/89 and 1998-2001, it would have no warming trend like the East Pacific!

    Tom Curtis at 146 says: “Interestingly, in his comment @137 Tisdale quotes Compo and Sardeshmuk…”

    You then go on, Tom, to attempt (and fail at your attempt) to fault me for using a single index in the above graph, but then immediately compromise your position by referring to your preferred single index, the Southern Oscillation Index.

    Second, you’ve apparently misunderstood Compo and Sardeshmuk. Their discussion of a using a single index had to do with regression analysis. They wrote:

    In particular, defining ENSO in terms of a single index and ENSO-related variations in terms of regressions on that index, as done in many previous studies, can lead to wrong conclusions. This paper argues that ENSO is best viewed not as a number but as an evolving dynamical process for this purpose.

    In this graph, I did not use the ENSO index in a regression analysis. I simply averaged the NINO3.4 sea surface temperature anomalies. There’s a very basic difference, Tom.

    You also failed to recognize the importance of what I wrote after I quoted Compo and Sardeshmuk. It was:

    Compo and Sardeshmukh have not accounted for the left over warm water associated with major El Niño events, like the 1986/87/88 and 1997/98 El Niños. In time, maybe they will.

    Compo and Sardeshmuk are a step in the right direction, as I noted before I quoted them in my comment at 137.

    Tom Curtis at 146 says: “Therefore simply taking the SST anomaly in the Nino 3.4 region over vastly different time periods cannot plausibly be considered a measure of ENSO activity. It in no way allows for the effects of other factors which we know will cause changes in the SST in the Nino 3.4 region as much as anywhere else.”

    What “other factors” are referring to, Tom? Are you aware the authors of peer-reviewed papers about ENSO consider NINO3.4 sea surface temperature anomalies to be “a measure of ENSO activity”? An example is the Giese et al (2009) paper The 1918/19 El Niño. They argued that the 1918/19 portion of the 1918/19/20 El Niño was underestimated in the NINO3.4 sea surface temperature reconstructions, and that it was likely comparable in strength to the 1982/83 and 1997/98 El Niño events. Giese et al (2009) also suggested that the 1912/13 and 1939/40/41/42 El Niño events were also under-rated. If as you say, the NINO3.4 data “cannot plausibly be considered a measure of ENSO activity”, why would Giese et al (2009) have even written their paper, Tom? Why would NOAA use NINO3.4 data as the basis for its Ocean NINO Index? Why would Kevin Trenberth recommend NINO3.4 data over the SOI? Read on.

    Please also note the dataset used by the ENSO experts who wrote that paper, Tom. It was HADISST, the same one I used. It was not HADSST3 or HADSST2, which you used in your comment 151.

    With respect to your preference to the Southern Oscillation Index data, are you aware of all of the difficulties with that dataset? Refer to Trenberth (1997) The Definition of El Niño. He writes (my boldface):

    Various versions of the SOI exist although, in recent years, most deal only with atmospheric pressures and usually only those at Darwin and Tahiti. In using the SOI based on just two stations, it must be recognized that there are many small scale and high frequency phenomena in the atmosphere, such as the Madden-Julian Oscillation, that can influence the pressures at stations involved in forming the SOI, but which do not reflect the Southern Oscillation itself. Accordingly, the SOI should only be used when monthly means are appropriately smoothed (Trenberth 1984, Trenberth and Hoar 1996a). For many years, Tahiti data were available only after 1935. Ropelewski and Jones (1987) outline an extension of the SOI prior to then using newly discovered Tahiti data, and they also discuss different ways of standardizing the data for use in the SOI. However, there are questions about the integrity of the Tahiti data prior to 1935 (Trenberth and Hoar 1996a), as the Tahiti-Darwin correlation is much lower in spite of strong evidence that the SO was present from other stations, and the noise level and variance in the early Tahiti data is higher than in the more recent period. Although Ropelewski and Jones (1987) state that they believe that months with data contained a full complement of daily values, several monthly means are missing and the monthly means that are present for the earlier period are more consistent with the view that they originate from an incomplete dataset in which values contributing to monthly means are missing. There are also questions about whether the diurnal cycle in surface pressure, which contains a strong semidiurnal tide component, has been adequately dealt with in forming the means. Ropelewski and Jones (1987) use a 5 month running mean to define their indices (as is done in NOAA's Climate Diagnostics Bulletin).

    It took a couple of years after that paper, but in response to those deficiencies in the SOI, Tom, NOAA and many scientists adopted NINO3.4 sea surface temperature anomalies and the Cold Tongue Index (which is based on sea surface temperature anomalies of a similar region) as the better measure of the frequency, magnitude and duration of El Niño and La Niña events.

    Further to your comment 151: One of the reasons Giese et al used HADISST is because HADSST2 or HADSST3 are spatially incomplete. That is, there’s missing data. This can be seen in the output from the KNMI Climate Explorer of NINO3.4 data for the periods of 1912 through 1944 and 1944 through 1976, using a 15% cutoff as you did:

    HADSST2 NINO3.4 from 1912-1944

    HADSST2 NINO3.4 from 1944-1976

    HADSST3 NINO3.4 from 1912-1944

    HADSST3 NINO3.4 from 1944-1976

    Note how much data is missing. I’ve limited the graphs to 3+ decade periods so that you could see all of the missing data, unlike your graphs in comment 151. That lack of data appears to have skewed the results you presented in comment 151, Tom.

    If you had asked me what dataset I used in this graph, Tom, I would have told you HADISST. It’s been infilled so there’s no missing data. Here are the HADISST-based graphs from the KNMI Climate Explorer of NINO3.4 SST anomalies so you can visually compare them to the HADSST2- and HADSST3-based graphs above:

    HADISST NINO3.4 from 1912-1944

    HADISST NINO3.4 from 1944-1976

    The differences between the HADISST-based NINO3.4 data and the others are quite extraordinary. Also if you had asked, I would have explained why I used HADISST—the HADSST2 and HADSST3 datasets are spatially incomplete in the NINO3.4 region. And I would have told you I used the base years of 1950-1979 in agreement with Trenberth (1997) The Definition of El Niño. He stated that 1950 to 1979 was the best base period for NINO3.4 sea surface temperature anomalies. Trenberth writes:

    Figure 1 shows the five month running mean SST time series for the Niño 3 and 3.4 regions relative to a base period climatology of 1950-1979 given in Table 1. The base period can make a difference. This standard 30 year base period is chosen as it is representative of the record this century, whereas the period after 1979 has been biased warm and dominated by El Niño events (Trenberth and Hoar 1996a). Mean temperatures are higher in the Niño 3.4 region than in Niño 3 and its proximity to the Pacific warm pool and main centers of convection is the reason for the physical importance of Niño 3.4.

    If you had asked, Tom, I would have been happy to explain all those things. You could have saved yourself a lot of time, and you would not have jumped to all the wrong conclusions.

  50. It's El Niño

    Bernard J. says at 145: “Specifically, I would like to know by exactly how much Tisdale believes that "[d]ownward longwave radiation" does or does not contribute to warming of the planet in terms of a particular DLR flux, and by what mechanisms that warming does - or indeed does not - does not occur.”

    I believe this has been the underlying topic of discussion, Bernard J. The satellite-era sea surface temperature records and the ocean heat content records do not indicate that downward shortwave radiation has made any contribution to the warming.

    Bernard J. says at 145: “Numbers and primary references would assist to make an objective and nuanced case.”

    I’ll present the four datasets once again. For sea surface temperatures there’s the East Pacific Ocean and the Rest of the World data. In case you’ve missed this, the divergences during the La Niña events of 1988/89 and 1998-01 are when the Rest of the World data acquires its long-term trend. If the Rest-of-the-World sea surface temperature data cooled proportionally during the La Niña events of 1988/89 and 1998-2001, it would have no warming trend like the East Pacific! For ocean heat content, I presented as examples the Tropical Pacific and the North Pacific north of the tropics, both of which contradict the hypothesis of manmade greenhouse gas-driven global warming.

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