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  1. Rasmus, the IPCC wrote a report about this last year, generally referred to as SREX. You can find it on the web.

    [Response: Yes, and it discusses some of the same issues, e.g. heat waves. But the SREX does not include many of the more recent papers cited here. And it does not appreciate some of the new analytical methods, e.g. recode-breaking statistics. -rasmus]

    Comment by Paul Matthews — 13 Mar 2013 @ 12:09 PM

  2. I believe the climate denialists have forced the discussion to the wrong test; the wrong argument.
    The “Greenhouse warming” effect is based on well known, simple physics. The null hypothesis should be “CO2 and other gases have caused and will cause less heat to leave Earth in the stratosphere. We know this because we have measured it, and because the Earth is x degrees warmer than it otherwise would be. The only unknowns are how long it will take to reach the new temperature and the exact increase level.”

    The null test should not be “the earth is not warming/climate change is normal/caused by …”

    Climate change denialists should be asked “what mechanism is keeping the physically expected warming from happening?”

    Ken Rushton, computer systems analyst

    Comment by Ken Rushton — 13 Mar 2013 @ 12:45 PM

  3. Kan Rushton,
    I’m sorry, but it is time for a pedantic rant. Please do not use the term “null hypothesis” for a situation in which you are not comparing two statistical models. Null hypothesis has a very specific meaning. It is a tool of statistical methodology, nothing more. What is more, you never, ever, under any circumstances accept the null hypothesis–you simply conclude that your results are not sufficient to reject it.

    The proper term for the greenhouse effect is “generally accepted science”.

    Comment by Ray Ladbury — 13 Mar 2013 @ 1:40 PM

  4. The missing reference:

    Petoukhov, Vladimir, Stefan Rahmstorf, Stefan Petri, and Hans Joachim Schellnhuber. “Quasiresonant Amplification of Planetary Waves and Recent Northern Hemisphere Weather Extremes.” Proceedings of the National Academy of Sciences (March 1, 2013). doi:10.1073/pnas.1222000110.
    http://www.pnas.org/content/early/2013/02/28/1222000110

    Comment by CM — 13 Mar 2013 @ 4:17 PM

  5. “Climate change denialists should be asked “what mechanism is keeping the physically expected warming from happening?”

    Interesting point. An answer: the radiative forcing of CO2, including feedback (negative as well as positive), is still unknown – not in general terms, but in the specifics. This is why there are still Scenario A, B and C under discussion.

    If the forcing factor were well known, the only variables we would be dealing with are TSI and ppmv pCO2 increases. The first is minor and, as defined, considered insigificant for AGW projections. The second is fairly well known and could, for any given moment, be given a darn good figure. That would mean that a specific Scenario would be laid out. But they are not.

    If we consider the last 15 years of global temperatures in the light of continued CO2 warming, one must say that some cooling mechanism, say aerosols (perhaps the moderate volcanics) are playing a role. This suggests that the power of CO2 is equal to that of the aerosols, or close to it.

    However, if we consider that the 1975-1997 period was a period of “brightening” due to aerosol reduction (pollution controls), then we have to admit that SOME of the 1975-1997 period was not just CO2 warming. So the actual CO2 forcing is less than what is calculated simply by the changes in pCO2 and global average temperature.

    That would give us a top-down and bottom-up range for CO2 forcing. Which would limit Scenarios to, again, variations in CO2 increases and TSI changes.

    Note that the “cooling” factor doesn’t have to be aerosols, and could be the net effect of various things, including heat release-retention of the oceans.

    So to give an answer: the cooling mechanism is because the radiative forcing is not as strong as modelled relative to natural factors. The answer comes with suggestions for value limiting calculations and predictions for the next few years.

    Comment by Doug Proctor — 13 Mar 2013 @ 5:44 PM

  6. Ken Rushton #2,

    Ray’s nomenclature issue aside, I think you’re giving the denialists WAAAAAAY too much credit here. They’re not, in the main, carefully re-framing the debate by forcing the discussion anywhere. They’re simply denying AGW, for whatever reasons they may have. These might range from commercial sponsorship (either direct or indirect) to sheer bloody-mindedness, as in the case of a person (I am outside the US) I know personally who refuses to accept the objectivity of the scientists because he himself spent decades in a government job in an area where everybody brought a political agenda to EVERY issue.

    The analogy I draw comes from a marriage break-up long ago, where I was asked as a numbers guy to advise a friend of my mother who was having difficulty getting an agreed house valuation. The other party was sticking to an absurdly high amount, given the location and the (extremely poor) state of repair. I eventually pointed out that this person was working backwards from the amount of money they wished to receive at settlement, and was simply advancing reason after reason for the high valuation to bolster their case for this amount, AND WOULD NOT STOP ARGUING.

    I see the same thing with denialists (as distinct from real sceptics). They are working backwards from their need or desire to deny AGW, and will keep arguing. Sometimes the arguments will seem (and indeed be) totally ridiculous, but that will NOT stop the denialists from continuing to advance them if they don’t have anything better.

    Comment by ozajh — 13 Mar 2013 @ 6:26 PM

  7. Ray @ 3,

    It may well have a specific meaning in statistics, but it has a more general meaning in Science

    Comment by Keith Woollard — 13 Mar 2013 @ 6:52 PM

  8. Keith Woollard,

    [edit] The null hypothesis is not ever, under any circumstances in this Universe a “viable” theory. You never accept the null hypothesis–you merely cannot rule it out relative to your actual hypothesis. The sole role of the null hypothesis is statistical hypothesis testing.

    Comment by Ray Ladbury — 13 Mar 2013 @ 7:23 PM

  9. > null hypothesis:
    “Anything but the IPCC”
    > what mechanism?
    A hundred on offer; U-pick, mix and match
    > a more general meaning in Science
    [citation needed]. Seems to me any practice ignorant of statistics isn’t likely to be science, especially if it capitalizes “Science” in claiming it.

    Comment by Hank Roberts — 13 Mar 2013 @ 7:35 PM

  10. Is it possible to extract information on metascale storms, by using the output from a global
    climate model to initialize state and provide boundary conditions for a regional climate model?
    One could pick and choose those days when the conditions are ripe for severe weather, and then
    see if say the twenty worst days on the globally warmed model produce more/stronger storms than
    for the control.
    ~

    Comment by Thomas — 13 Mar 2013 @ 9:02 PM

  11. Is it too hard to go to the moon, eradicate smallpox or end apartheid? Is it too hard to build a computer that fits in your pocket? No? Then it’s not too hard to build a clean energy future, either. http://clmtr.lt/cb/pZF0Qd

    Comment by Juliorf — 13 Mar 2013 @ 10:02 PM

  12. Definition of null hypothesis
    noun
    (in a statistical test) the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

    from
    http://oxforddictionaries.com/us/definition/american_english/null%2Bhypothesis

    Comment by David B. Benson — 13 Mar 2013 @ 10:15 PM

  13. Mark Twain anticipated the linkage of climate change and national security over a century ago, when he observed that while whiskey is for drinking, water is for fighting over.

    Since evaporation consumes more water than irrigation in much of the world today, water conservation may soon rival warfare as an extension of politics. conflict management

    Comment by Russell — 13 Mar 2013 @ 10:50 PM

  14. Dear Rasmus,

    I think it would be useful to clearly distinguish between changes in extremes expected as a result of climate change in the future and changes in extremes that should theoretically be visible after the 0.8 K of warming seen since the preindustrial times. And since you mention the PBS documentary, it would be good to discuss the claims made in there too.

    The central theme of your post seems to be that we are making good progress in the science of extremes, and to that end you have cited a number of interesting recent studies. Beyond this I was not sure where you actually stand on the PBS documentary or in general on our knowledge of extremes.

    If I may: Do you stand behind the conclusions of the IPCC SREX? Do you stand behind the claims made in the PBS documentary? And if not, which claims do you agree with, which ones aren’t you sure about, and which ones do you dispute?

    It seems there is a whole lot of noise in the media about extremes – if I take the media at face value I would believe that it is ‘virtually certain’ that there will be more extreme cold events in the year 2100 as a result of climate change. This is, of course, the opposite of the conclusion of the IPCC SREX (and common sense).

    I think there is an opportunity in writing this post to assist in clarifying some of this.

    Kind regards,
    Alex Harvey

    Hi Alex, here is my position:

    [Response: Do you stand behind the conclusions of the IPCC SREX? Some of my views are expressed in two previous posts (here and here). I think that the SREX did not take into account some of the empirical-v
    based work on tropical cyclones and the record-breaking events, but on the whole, I think it provides a reasonable picture of what was out in the scientific literature at the time when it was written.

    Do you stand behind the claims made in the PBS documentary? The PBS is of a different nature and purpose to the SREX. The SREX is supposed to reflect and assess the scientific literature. The PBS episode is an expression of concern, and these are based on scientific studies, although for some of these, there is not yet always a clear picture, as discussed in my piece (tornadoes, storms).

    …which claims do you agree with, which ones aren’t you sure about, and which ones do you dispute? I’d say that I’m not sure about several of these questions, and the answers to these questions are still in the process of being formed.

    -rasmus]

    Comment by Alex Harvey — 13 Mar 2013 @ 11:55 PM

  15. “123 weather records broken in 90 days of summer” – might be telling us something.

    http://www.abc.net.au/local/stories/2013/03/04/3702888.htm

    These records ranged from the highest maximum temperature averaged over the whole of Australia for one day to daily rainfall totals at specific locations.

    Comment by Peter Smith — 14 Mar 2013 @ 12:28 AM

  16. [Response: The idea of hypothesis testing and significance tests is not irrelevant. How does one conclude that a finding is acceptable? The CERN teams used 5 sigma as the standard for finding the Higgs boson. As far as I know there is no accepted standard like that for AGW. I find that the relationship between CO2 and temperature is well beyond 5s. But when you get into looking at the relationship between extreme weather events and AGW, there is nowhere near that much evidence. It’s tempting to study the weather, because that is what the general public sees most. But it is dangerous to draw conclusions and publicize them, because they are likely to turn out to be false, and that will detract from the credibility of climate science generally.

    [Response: 5s is appropriate for the CERN-type experiments with huge amount of data, but it’s totally impractical for weather – not even weather forecasts. With that confidence limit, a large part of science would not be published. -rasmus]

    Comment by T Marvell — 14 Mar 2013 @ 1:44 AM

  17. Climate change is real and we must take an educated approach to deal with it. Pathfinders need to inform the general population about the realities in a neutral tone. I am making an effort with a petition directed to the Secretary-General of the United Nations, Ban Ki-moon at https://yourclimatechange.org/.

    Those who are interested in the cause, please join hands with me in my attempt to protect the Earth from anthropogenic climate change. Please sign the petition and share the page with your friends, family and colleagues who might be interested.

    Thanks
    -Prof. Ranga Myneni’

    Comment by Ranga myneni — 14 Mar 2013 @ 3:57 AM

  18. Paul Matthews, were you being factious per chance?

    SREX: Authors and expert reviewers (p550)

    Norway
    Torgrim Asphjell, Climate and Pollution Agency
    Rasmus Benestad, The Norwegian Meteorological Institute
    Tor A. Benjaminsen, Norwegian University of Life Sciences
    Elzbieta Maria Bitner-Gregersen, Det Norske Veritas AS

    Comment by Hasis — 14 Mar 2013 @ 4:00 AM

  19. The 5s criteria is a standard discovery criterion for a counting type experiment a la CERN.

    [Response: We are not talking about CERN here. When it comes to climate and weather, we are really dealing with risks for all intents and purposes – and there are different requirements to what is acceptable probabilities. -rasmus]

    Comment by Flakmeister — 14 Mar 2013 @ 7:07 AM

  20. #17, Edim–“How can anyone disagree with this?”

    From the bottom up: ‘this’ begins with a false premise; everything else follows from that. It’s the Inhofes of this world that are doing the misleading on AGW.

    #18, Salamano–Did you read the same post that I did? To me, it describes an ongoing process of looking to see what connections may exist, and better understanding those we do do exist.

    Comment by Kevin McKinney — 14 Mar 2013 @ 7:39 AM

  21. Re: @2

    Trying to frame the discussion. I sympathize with your desire to shift the default position past “Whu? Can this really be happening?” and to get on to solutions. It seems to me that the MSM treatment of this whole subject is very sluggish.

    FWIW, one attempt to cut through the fog by analogy:
    http://www.commondreams.org/video/2013/03/14

    Comment by Radge Havers — 14 Mar 2013 @ 8:28 AM

  22. T. Marvell,
    Please, please, please tell me that you were not trying to hold particle physics to the same standards as particle physics.

    Off-topic warning

    The way particle physics works is that you reconstruct the putative masses of parent particles from the kinematics of the daughter particles into which they nominally decayed. If the “daughter” particles did not really come from a decay (a vertex detached from the original interaction site), they result in noise. If they did, then they ought to reconstruct the mass of the particle they came from. In the course of this exercise, you might generate hundreds or even thousands of such mass plots, each with a different set of kinematical “cuts” to limit the noise and bring out the signal. These cuts cannot be random–they should be motivated by physics. Nevertheless, given all the trials, it is just about inevitable that you would get 3 sigma effects even if there were no particle to reconstruct.

    So, 5 sigma in particle physics ain’t really five sigma of certainty. My doctoral dissertation (which is sinking into the obscurity it so richly deserves) was in experimental particle physics.

    Comment by Ray Ladbury — 14 Mar 2013 @ 8:33 AM

  23. http://www.washingtonpost.com/blogs/capital-weather-gang/post/how-global-warming-spoiled-the-snowquester/2013/03/14/cf532510-8c0f-11e2-9f54-f3fdd70acad2_blog.html

    quotes

    “Chip Knappenberger and Pat Michaels, climatologists affiliated with the libertarian Cato Institute and skeptical of dire climate change predictions, concede the “non-record-breaking non-extreme non-snowstorm” was “consistent with global warming.” But they conclude the involved interplay between global warming and complicated storm processes make it “virtually impossible to know” the overall effect.”

    The post has some good info along with the ‘advocacy science’ denial quote.
    http://www.washingtonpost.com/rf/image_606w/WashingtonPost/Content/Blogs/capital-weather-gang/201303/images/snowfall-snowquester.jpg

    Comment by Hank Roberts — 14 Mar 2013 @ 10:52 AM

  24. I would love some professional feedback
    I have just authored/published “The Green Game,” about Eco-responsibility, green politics, youth and education in a twist filled, exciting mystery. The Green Game is an onion with many layers. It is about real and fictional businesses. Three students develop an internet game based on voting on green issues that changes the world. The “Green Game” is an enteraining message filled novel, ideal for a discussion between teens and parents. If you are interested it is available at my e-store http://www.createspace.com/4147272 with a discount. The discount code is NW6BBYBS. It is also available in Kindle and paperback at Amazon. More is available at my web site http://www.xanaducorporate.com Any help getting the green word out help will be appreciated. Joe Beach 952-920-9160

    Comment by Joe Beach — 14 Mar 2013 @ 11:36 AM

  25. An intriguing item on a possible (though ‘longshot’) mitigation measure:

    http://blog.sfgate.com/nov05election/2013/03/12/battle-lines-forming-on-carbon-tax/

    Comment by Kevin McKinney — 14 Mar 2013 @ 12:22 PM

  26. This comes from a non-scientist who follows this site and other sources in an effort to understand what the future may bring, climate-wise, for the place where I live now and for where my family and I may relocate to in the future. I am appreciative of the work of the climate scientists and of those who provide such knowledgeable commentary in this section.
    There appears to be discouraging subtextual narrative coming from many of the sources. It goes something like this: “Given the amount of CO2 already dumped into the atmosphere, and the amount that will inevitably be dumped in the future because of the world’s existing fossil fuel-dependent infrastructure, we must resign ourselves to the damage to come, and our present efforts will make little difference so we may as well just give up on any conscious, political effort to change the infrastructure and instead just sit by and let the process be managed by market forces. Plus the world’s governments are useless in the face of this climate catastrophe anyway.”
    This narrative gains traction in part because scientific prediction of future climate is by necessity couched in terms of probabilities and alternate scenarios and science lingo … and the times are still far off when the worst effects of the warming will be felt. For someone like me the future is filled with great uncertainty. It’s hard to chart a course.
    I wish I could find a clear and simple prediction of the future path of climate change for the next 100 or so years, one where the author uses his/her best guesses as to what scenarios will play out. Such a prediction would be more science fiction than science, involving assumptions regarding future politics, technical innovations, adaptation, etc. But for a layman such as myself it would be useful. If any of you folks out there knows where to find this — from as reputable a source as possible — your recommendations would be much appreciated.

    Comment by S.B. Ripman — 14 Mar 2013 @ 12:53 PM

  27. Ranga Myneni @16. It’s good to see Prof. Myneni post here. Perhaps you’ve addressed this question elsewhere and if so my apologies for the repetition. I have a question as to whether your views were accurately represented in the Wall Street Journal editorial by Matt Ridley back in January, entitled “How Fossil Fuels Have Greened the Planet”

    http://online.wsj.com/article/SB10001424127887323374504578217621593679506.html

    In the article, Ridley refers to your work that the Earth has been greening over the last 30 years and says that there are two possibilities to explain this result, changes in the climate (meaning increased warmth or rainfall) and increased carbon dioxide. He then goes on, allegedly quoting you:

    “Dr. Myneni reckons that it is now possible to distinguish between these two effects in the satellite data, and he concludes that 50% is due to “relaxation of climate constraints,” i.e., warming or rainfall, and roughly 50% is due to carbon dioxide fertilization itself. In practice, the two interact.”

    I note that the part where he says “roughly 50% is due to carbon dioxide fertilization itself” does not actually have quotation marks around it. Prof. Myneni — did Matt Ridley put words in your mouth or did he accurately represent your views and your research. Thank you in advance for addressing this matter.

    Comment by JoeT — 14 Mar 2013 @ 1:29 PM

  28. My first thought on Matt Ridley is, why discuss denial at this point in history? It’s time to go all Nike on this and Just. Do. It. Buuut, since it’s been brought up, the best response to Ridley’s piece is that it is a classic case of cherry picking.

    While the thought had been earlier on that CO2 might increase growth well into the future, we have since found that CO2 response is mixed (C3 vs C4 plants)…

    http://www.ciesin.columbia.edu/docs/004-038/004-038a.html

    and heat will limit plant growth in the long run.

    http://www.guardian.co.uk/environment/2013/jan/13/global-food-crisis-heatwaves-crops

    Further, CO2 preferentially supports some sorts of plants that give us fits, such as increasing growth in allergenic plants. We reach negative returns quickly in terms of extreme weather affecting crops.

    The problem with some some aspects of climate science is the basing of discussion in averages rather than effects of extremes. As we all know, averages are more a fantasy than extremes are; they don’t really exist in our day-to-day world. I believe this underplays the urgency and leads to some degree of complacency.

    Ridley chooses to ignore every negative effect of FF’s on greening, such as death of soils, desertification, eutrophication, weather extremes, long-term effects of CO2 and heat, etc.

    Whether or not Ridley correctly quoted Ranga Myneni or not is almost irrelevant. If Myneni’s work has found what Ridley said, it is as expected up to a certain point with AGW and will not be the long-term result of higher CO2. If he distorted it, well, that is what climate denial is and is certainly expected from someone with Ridley’s views. Do note Ridley does not link to Myneni’s work, at least not in the version I found access to. If this is true in the WSJ version, too, then Ridley most likely is not wanting people to read the whole work.

    I do think these two points from the conclusions are perhaps most germane:

    http://cliveg.bu.edu/greeningearth/ssnltydim/main-findings.html

    The tight coupling between temperature and vegetation seasonality hides the fact that vegetation seasonality in the Arctic is accelerating over time (landscape greening rate increasing over time) and decelerating (greening rate slowing down over time) in the Boreal regions.

    So we get Arctic Amplification and negative crop effects, or at the very least diminishing returns, and desertification might be a reasonable interpretation of this, no?

    It should be clear to all that the extremes of temperatures, relatively thin soils, short growing seasons and extent of melting permafrost is not likely to make the northern latitudes highly productive farming areas any time soon. At the same time, crop losses from extreme weather events (floods, high and low temps, e.g. false spring in the US in 2012) are already causing crop losses in the mid-latitudes.

    Therefore, we do not know how vegetation seasonality (i.e. plant growth, species distribution) will change in the future.

    While Ridley wants to imply this is all just *great* news, the research concludes the future is not at all clear.

    Safe to say, and not intending to speak for the good Dr., Ridley’s (to be overly kind) interpretation, or at least his implication, is invalid.

    Comment by Killian — 14 Mar 2013 @ 3:13 PM

  29. 25 S.B. Ripman said I wish I could find a clear and simple prediction of the future path of climate change for the next 100 or so years

    When the worst case scenario is not yet known, and keeps getting worse and worse, the best risk assessment is to plan for the worst case scenario as currently known and perhaps a bit more.

    However, the effects of climate are and will continue to be highly variable from location to location. First step? Choose your location.

    Second step, find all you can on future scenarios and see where your chosen area falls on such maps, paying attention primarily to high temperatures, precipitation, water sources and climate zones. Be sure to adjust for changes in climate zones. (They are creeping northward at roughly one zone further north per decade. See U.S. climate maps for the last 20 years and note changes. Updated every ten years; most recent was within the last three years. By 2100 Michigan will potentially have Texas’ climate, e.g. Detroit currently has northern Kentucky’s former climate.)

    Third, learn about homestead establishment. (The principles involved will be applicable regardless of where you are going to be.) Then start planning specific to your location.

    There is no book that could do this for you unless you found an author that was both prescient and writing about the same climatic zone you intend to be in. Shortcut: take a permaculture course or read up on it.

    Comment by Killian — 14 Mar 2013 @ 3:30 PM

  30. S.B. Ripman,

    I don’t know whatall that was about, but I do think you’d best ignore it. Your “simple” question is the holy grail of results, unattainable and beckoning like the pot under the rainbow. Scientists are doing their best, but uncertainty will reign, augmented by a massive confusionist campaign deeply imbedded in the profit motives of some of the wealthiest corporations on earth and their deluded or dishonest followers.

    For a layperson’s mix of information, I’d recommend ClimateCentral:

    http://www.climatecentral.org/

    I also borrow a favorite statement from a friend who like me is a little impatient with the boundaries of science:

    The thing about models, in the present instance, is that they are incapable of reproducing the current situation – not having all the necessary inputs – and the rapidly compressing timescale. These modelers were thinking in terms of decades or hundreds of years, when it may well all turn on a dime.

    We are stuck with scientists’ best efforts to model a complicated and chaotic system, checked by real-world observations of all kinds. But when you see obscurantism creeping in as an argument for do-nothingism, you can be almost sure this is calculated and dishonest.

    In terms of action, just do what you can, all that you can, to influence your legislators to stop sticking their heads in the sand. Then look around at what is happening and make practical arrangements if you can – community, energy, gardening, water, and the like. In short, use your noggin. It’s getting *choose a swearword* obvious!

    Given our propensity to seek the easy way out, we will no doubt make things a whole lot worse with some temporary geoengineering scheme like sulfur dioxide that in the long run will complicate and magnify consequences. Our faith in others’ ability to take care of our problem at some remove in time or space is legion.

    Comment by Susan Anderson — 14 Mar 2013 @ 7:36 PM

  31. Spoke a little hastily – some of the “whatall” was quite sensible, but that doesn’t make me take back any of the rest of it.

    fwiw, I’m a layperson too, but I prefer to admit my ignorance and accept expertise where it can be found. This is one of the trustworthy places to find some of the most skilled people at work.

    Comment by Susan Anderson — 14 Mar 2013 @ 8:15 PM

  32. Flakmeister – there is really good reason why accelerator experiments have 5/6s rather than usual 3s common in other science. Do you know what it is? (Hint – same reason doesnt apply in many other sciences).

    Comment by Phil Scadden — 14 Mar 2013 @ 9:11 PM

  33. For S.B. Ripman:

    I suggest printing these wallet-size and handing them to anyone saying “we must resign ourselves to the damage to come, and our present efforts will make little difference so we may as well just give up ….”
    http://imgsrv.gocomics.com/dim/?fh=039cf8a00ba4b03f044e33001172e789&w=750.0

    In fact, collect the whole set: http://climatesight.org/image-collection/

    Comment by Hank Roberts — 15 Mar 2013 @ 12:31 AM

  34. S.B. Ripman,

    I don’t think it’s controversial that given the amount of GHGs we have already pumped into the atmosphere we have already committed ourselves to a certain amount of climate change and there is nothing we can do now to prevent that. It doesn’t necessarily follow though that we should give up on the possibility of concerted political action to minimise the consequences and to mitigate as far as possible against even more serious climate change. You will certainly hear people arguing that such concerted action is a pipe dream but they will mostly be either outright contrarians, or those who like to portray themselves as the “reasonable middle ground”.

    And that’s what gets me about some of the arguments made by such people. They like to portray people like myself and many of the commenters here as “alarmists” and “doommongers” and accuse us of having an overly pessimistic outlook, but actually I think most of us believe that although the threat we face is very serious it is one that humanity is capable of addressing both from a practical perspective and in terms of building the necessary political will for such action to happen. It is not us arguing that any such attempts are necessarily doomed to failure and/or will wreck the economy and send us back to the stone age. Yes, the lack of progess so far can be dispiriting but I would say that overall our outlook is realistic but also optimistic, as opposed to the contrarians and others whose outlook is either absurdly panglossian WRT the effects of climate change or excessively “alarmist” about attempts to address it.

    Comment by andrew adams — 15 Mar 2013 @ 8:05 AM

  35. @31

    It has been called the “look else where” effect…

    If you peruse the H-> gamma gamma papers from the LEP era and if you look closely, at one point there was close to a 4 sigma “signal” at 30 GeV in the combined Z peak, 130, 136 GeV root(s) OPAL data…

    Comment by Flakmeister — 15 Mar 2013 @ 8:13 AM

  36. you don’t need need tipping points to justify CC anymore. Any science I’m aware of recognizes extreme events as non-normal and pretty near impossible to deal with In a meaningful quantitative way, Black swans they are as far as descriptions go.
    Thirty years of developing the body of knowledge called Climate Science has put the world in a position to deal with planning for CC.pretty responsibly.New Orleans and Long Island can better design their leaves/sea-walls to withstand future storms. Chinese builders of a new coal-fired power plant (they need one a day) can figure out how to make it as climate friendly as possible.
    Try David Victor’s book; he proposes moving forward with local approaches based on capabilities. iMO his approach can be made to work
    jP

    Comment by BallyWho — 15 Mar 2013 @ 8:32 AM

  37. “Global climate models may provide a tool for studying such links, but they are designed to provide a picture of general large-scale features such as the greenhouse effect and how the air moves around, rather than local extreme phenomena. For some types of extremes such as heat waves, they can nevertheless provide valuable insight (Hansen et al., 2012).”

    I don’t think you have the reference right here. That paper had little to do with models and was very much observation based.

    Comment by Chris Dudley — 15 Mar 2013 @ 9:25 AM

  38. Having just seen the new movie “Chasing Ice” — I highly recommend finding a showing if you can find a showing near you: http://www.chasingice.com/see-the-film/showtimes-2/
    Else, eventually, they’ll have a DVD/Blue-Ray distribution with extra material.

    I saw a presentation with one of the filmmakers — among his comments he said they went repeatedly to the scientists interviewed, to get the presentation right and the brief excerpts well supported. The film spends only a few seconds apiece with the scientists, on the basic information about change over time, and does a good job of using presentation graphics, not just talking heads, for those.

    The movie is almost all filmed outdoors, and almost entirely about the work of getting long time exposure cameras out onto the ice and getting the interim results together (many of the cameras are still in place and still collecting images — Greenland, Iceland, and Alaska).

    Comment by Hank Roberts — 15 Mar 2013 @ 10:04 AM

  39. Folks, you can’t cross-reference by the big gray number.

    Those are assigned each time you open the page.

    (As I understand the software — I’m a reader, not a Contributor/scientist):

    Since the last time you looked, a boring response may have been moved to its proper place, or a thoughtful one delayed for reading and then posted with a comment added inline. The big gray number changes to reflect that.

    Here’s how to indicate who you’re replying to:
    Mention the name/nym and quote the timestamp — this thing: 15 Mar 2013 at 10:04 AM

    To copy it as a link, hilight, right-click, “view source” and select all, copy that, paste it in).

    Comment by Hank Roberts — 15 Mar 2013 @ 11:37 AM

  40. 26 S.B. Ripman: “Drought Under Global Warming: a Review” by Aiguo Dai
    http://www.atmos.albany.edu/facstaff/adai/
    The future still depends on present and future actions of large groups of humans.

    Comment by Edward Greisch — 15 Mar 2013 @ 12:54 PM

  41. The question is not whether or not humans are the culprit that lead to global warming. The question should be a collective consciousness that realizes that there is a problem and what can we do as a society to try to repair the problems that are happening as a result.

    Comment by Turnkey Websites — 16 Mar 2013 @ 1:03 AM

  42. Dear Prof Ranga Myneni @17,

    while I salute you for trying to make a real difference in the world, unless your proposal somehow seriously addressess the dynamics of global population growth and the the issues of physical limits of resources on a finite planet, I believe your attempts will be doomed to failure. What you are asking for can only be accomplished with profound and radical paradigm change everywhere on the planet. Given what I have learned about human nature, over the soon to be 60 years, that I have spent on this planet I find that extremely unlikely.

    Besides humanity´s CO2 footprint and ecological footprint I think we should also be concerned with our Thermodynamic Footprint. There are too many people on a finite planet consuming too many resources and trying to use more ecosytem services than the ecosytems can possibly provide. We have constructed a highly complex, and now quite fragile artificial ecosystem upon which we depend for our survival. The entropy of this system is exponentially diverging from what used to be an ecologically stable thermodynamic equilibrium.

    RealClimate already does a superb job of addressing our CO2 footprint.
    So no link is necessary for that here.

    Here´s a link to some data on our Ecological Footprint:
    http://www.footprintnetwork.org/en/index.php/GFN/page/earth_overshoot_day/

    A Quick Primer in Ecosystem Thermodynamics 101:
    http://www.uni-kiel.de/ecology/users/fmueller/salzau2006/ea_presentations/Data/2006-07-05_-_Thermodynamics_II.pdf

    Ecosystem Thermodynamics, meet Joseph Tainter´s collapse of complex societies.
    Thermodynamic Footprint
    http://www.paulchefurka.ca/TF.html

    This can´t continue for much longer. All the world´s current leaders are fiddling while the planet burns, in more ways that one. In comparison, Nero was but a rank amateur…

    If any economists are reading this and are still clinging to the hope that the current paradigm has a snowball´s chance in hell, or for that matter, the way things are going, even in the Artic… please consider that all economies are wholly owned subsidiaries of Global Ecosystems Inc. The irony of the fact that both the word ecology and economy have the same Greek root should also not be lost on you.

    Disclaimer: not that I really expect too many economists are stopping by at this site.

    Cheers!
    Fred Magyar

    Comment by Fred Magyar — 16 Mar 2013 @ 9:39 AM

  43. > Turnkey Websites says:
    > 16 Mar 2013 at 1:03 AM
    That link “Turnkey Websites” is a blogspambot, a clever one — ‘oogle it.

    Comment by Hank Roberts — 16 Mar 2013 @ 11:31 AM

  44. I Believe the only positive answer we can give back to the issues of our time, are home grown food, permacultural landscaping, community healing and energy harvesting, just like they describe over there

    http://whatisecology.com/how_to_produce_electricity/

    Comment by Xav Ier — 17 Mar 2013 @ 12:39 AM

  45. 40
    Edward Greisch says:

    “The future still depends on present and future actions of large groups of human.”

    Thank you Mr. Greisch and others for the wise commentary. Aren’t we all doing our best, at the ballot box and with our pocketbooks, and at the pulpit when avilable to us, to bring about positive action?
    What I’m really hoping to find out, here and at other sources, is just how bad things are going to get in the next 100 years. It seems fair to assume that the governments of the world are going to be feckless for about 10 or so more years but then the shrinkage of the world’s ice fields and the weather disruptions are going to force sanity on them and we’ll finally see some major, concerted action to address the problem. But by then the atmosphere will be much more polluted than it is now and the warming process will continue for decades and centuries. And future generations will curse us and curse us, as we moulder in our gradually warming graveyards.
    So with the help of this dialogue it appears I’m answering my own question. The most likely scenario is one of the more pessimistic ones posited by the IPCC, and things are going to get quite bad, and now is the time to plan accordingly.
    ps. I’m not sure the permaculture approach works very well when applied in a world with a rapidly changing climate.

    Comment by S.B. Ripman — 17 Mar 2013 @ 11:02 AM

  46. Hank Roberts, I find a tilde “~” indicating “approximately” does the job, with the name. The numbers do change, so using them without a name is not helpful.

    SBR, you don’t want much, do you? (just kidding) Scientists are doing their best, but absolute knowledge is unlikely at any time, and in a chaotic system less so.

    Comment by Susan Anderson — 17 Mar 2013 @ 10:12 PM

  47. Benestad 2008 link is pointing back to this page.

    Comment by Alexandre — 18 Mar 2013 @ 9:00 AM

  48. In answer to the point ‘what can we do while the world burns’ and similar, I have launched a website that gives us something to do. It is called http://www.globaldemocracy.org. It shows you where to go to pressure decision makers to do the right thing – a a small action, granted, but an action nonetheless. It is hard to get it noticed among the billions of websites now floating in the ether. Any ideas for it’s improvement and therefore value welcome, at the contact us link, thanks.

    Comment by Bill Piper — 18 Mar 2013 @ 3:15 PM

  49. The 5 sigma thing again. I thought that was dead and buried a long time ago. If you run the same experiment 100,000 times, eventually you may get lucky, so you have to have extremely high confidence that any observation isn’t chance before you claim a new finding. Read this if you still don’t get it.

    Comment by Philip Machanick — 19 Mar 2013 @ 7:16 AM

  50. #27 – Ridley refers to your work that the Earth has been greening over the last 30 years and says that there are two possibilities to explain this result, changes in the climate (meaning increased warmth or rainfall) and increased carbon dioxide. He then goes on, allegedly quoting you:

    “Dr. Myneni reckons that it is now possible to distinguish between these two effects in the satellite data, and he concludes that 50% is due to “relaxation of climate constraints,” i.e., warming or rainfall, and roughly 50% is due to carbon dioxide fertilization itself. In practice, the two interact.”

    Among the AGW denialist crowd, many have taken the fallback position that if global warming is real, it’s actually a good thing because it will make the Earth greener.

    I’ve given that a little thought. Will people in the 22nd century be thanking us for making the world more tropical? I conclude that, for the most part, no. Yes, warming could be seen as a positive for the residents of Greenland and Siberia – assuming that can keep the hoards of climate refugees away. Those who likely not thank us are the billions of human inhabitants who live in the non-Arctic regions and will have to deal with heat waves and crop failures. Those who reside in low-lying regions may have to flee to higher ground (goodbye New York City, Amsterdam, Shanghai, etc).

    On the other hand, the greening may benefit reptiles. Dinosaurs could stage a comeback. I’m sure that they will be grateful to us.

    Comment by Paraquat — 21 Mar 2013 @ 8:31 PM

  51. 45ish SBR said, “What I’m really hoping to find out, here and at other sources, is just how bad things are going to get in the next 100 years.”

    In a way that’s a bad visualization because our future isn’t likely to be sigmoid with stability returned in 2113. One problem is that Humans Die Last. And not just Die Last, but Everything Else Dies Before Humans Get Terribly Uncomfortable. (except weeds and pest species, which tend to thrive on disaster)

    So, if things are “this” bad in 2113, then by 2123, 2113 could be a fond memory while we desperately mine hydrocarbons with which to build pesticides and dead zones – so you and I (or our descendants) can sit in air-conditioned comfort and lament the end of the world (but MY thermostat, well, I pay my electric bill, why should I suffer in heat? Seriously, dude, are YOU willing to disconnect your AC today? If not, then how can you expect your grandson to do it when it’s 10 degrees hotter outside?) Remember, we got from ice ages to interglacials with itsy bitsy orbital changes. Yeah, whaddaya think doubling CO2 BEFORE feedbacks will do? We’re still counting on a net negative feedback from the planetary system. “So far it’s absorbing half our emissions…” Oooooo, and for all of 100 years of ramp-up of emissions. You really want to bet on the natural feedbacks over the next 100 years? And that’s what it is. Scientists are smart, but this planetary system is ever so complex. Consequences on the ground? How about the Greenland Ice Sheet winter melt scare? If ALL scientists missed that, well, I’m guessing that there’s some more surprises out there…..

    It’s getting so one’s entire mindset about the future relies on a willingness or reluctance to go Climate Rogue and envision an artificial planet geoengineered specifically to prevent our demise. I see robots grinding mountains into dust and dumping them in the ocean to try to adjust the pH of the World….

    50 Para talked about greening. Just a layman, but I’ve got a TON of experience with plants, and their growth is usually limited by pH or some nutrient which simply doesn’t exist in nature in sufficient quantities. You have to bring in manure or fossil fertilizers. GIVEN that we’re talking about a post-fossil world, and there’s only so much manure, then all the greening caused by fertilizer (in fields and in runoff) is IRRELEVANT, and all the greening caused by a bit-o-warming is “just-the-past” and no indication of future changes via further warming. Warm your garden to 75F and things thrive. GREENING!!! Go a few more degrees, and everything dies. The downside of warming comes quickly and brutally when the plant’s capacity (and the soil’s availability) to evaporate water fails to keep up with cooling requirements.

    We don’t (usually) toss CO2 on plants even though it is dang near free. If CO2 were so grand, we’d just put rows of greenhouses at power plants and absorb all the CO2. Nope, we toss NPK, all of which are fossil. And then there’s temperature and humidity. Raise temps a bit and the growing season widens. Raise them a bit more and it starts narrowing and moving away from the solar max of June 21. When water availability and temperatures are best for plants in December and CO2 levels are double or triple the amount usable by plants without fertilizer and irrigation, then Houston, We Have A Problem.

    Yeah, your link smells very conclusiony and past-tense. Kind of like “YOU MISSED ME! GO AHEAD AND SHOOT ANOTHER 100 BULLETS!

    Comment by Jim Larsen — 21 Mar 2013 @ 10:23 PM

  52. SusanA said, ” I find a tilde “~” indicating “approximately” does the job, with the name. The numbers do change, so using them without a name is not helpful.”

    I’m one of those strange folks who think that a 10 minute programming fix is worth doing to save hundreds or thousands of folks many minutes of time. I can’t imagine any programmer above 6th grade installing a key field that changes essentially randomly. I surely can’t imagine ANY programmer actually paid to do their job leaving such a horrendous and EMBARRASSING bug in their product.

    I suppose I have different standards than most folks….

    dudes of RC, that bug really debases your site. You shouldn’t stand for it.

    Comment by Jim Larsen — 21 Mar 2013 @ 10:48 PM

  53. 49 and others – about the 5 sigma standard – The question is what researchers want to push as a standard for publicing research results. The probabilities associated with sigmas are understated, mainly because it’s humans who are producing the data and statistical relationships, not neutral data generators. #49 gives one of many reasons why human actions make significance tests misleading (other common examples are ideological bias, publication bias, and conformation bias).
    It was argued that climate science is too uncertan, and policy issues too important, to use anything like a 5s standard. I agree that policy concerns are important when setting the standard, but I would stress another policy concern – the ability of climate scientists to persuade others of the AGW threat. The relationship between CO2 and temperature is easily a 5s relationship, and it is important to get that relationship across to the public. There is no reasonable disagreement about it. Discussion of weaker relationships should remain in the academic literature, because there is too high a likelihood that these weaker relationship will prove to be wrong. There is no need to confuse the public and risk climate science getting an egg on its face, expecially over issues that are less crucial than the overall AGW effect. I cringe whenever I hear broadcasts about how climate warming is affecting specific parts of the country or increasing hurricanes or the like.

    Comment by T Marvell — 22 Mar 2013 @ 12:58 AM

  54. Jim Larsen @~52, I prefer not to be associated with your quibble about numbering. I’m happy to have the odd off-the-wall post removed at unpredictable intervals, and here because I’m interested in climate science. I am grateful to our hosts who have plenty to do are willing to share their knowledge and put in long hours to create a community here. I’m fine with the numbers changing. Commenters sometimes seem to get a magnified idea of the place of comments in blogs. If one takes salt at someone’s table, it’s still appropriate to remember it’s their table.

    Comment by Susan Anderson — 22 Mar 2013 @ 8:29 PM

  55. ps. If anyone wishes to “link” to a comment, that is always at the date and does not change.

    Comment by Susan Anderson — 22 Mar 2013 @ 8:31 PM

  56. > we’d just put rows of greenhouses at power plants and absorb all the CO2

    Make clean exhaust without the toxics available, just the CO2 and H20, and I’m sure there will be a great number of uses lining up to capture the stuff.

    It’s that other stuff in the output that would cost the earth to remove at the point source, they’ll tell you.

    Comment by Hank Roberts — 22 Mar 2013 @ 9:02 PM

  57. Excuse me Susan. I tried to dissassociate RC from the guy who installed that bug, but apparently I failed. My point is simply that it’s a pure-t-BUG that WASN’T created by RC, but it reflects badly and causes harm. My hope was that RC would simply contact the programmer and submit a bug-fix request. For such a simple bug, I can’t fathom it not being handled in a day or so (OK, here I’m projecting my standards on others)

    Yep, removing a post or boreholing it is grand, but that has NOTHING to do with what a key field displays. it actually adds information when the numbers go 51…52…54…

    Suggesting improvements is ALWAYS a good thing, regardless of who owns the table. Scientists understand – as science is all about ripping your best friend’s best work to shreds.

    Comment by Jim Larsen — 22 Mar 2013 @ 9:54 PM

  58. Jim, There is no “bug”. The post sequence is simply set by the date and time of the submission, the numbering happens when the posts are approved and so not always added to [or removed from] the stream in temporal order, some take more thought or scrutiny by a 2nd member. As others suggest, use the date and time perma-link

    Comment by flxible — 23 Mar 2013 @ 9:14 AM

  59. Re- Comment by Jim Larsen — 22 Mar 2013 @ 9:54 PM

    Changing post numbers is not a bug. When the numbers go up, the number of posts actually goes up. I believe that this happens when a post is held up by filter software or for the purpose of making an inline comment and this takes time, so when added into the queue later the numbers bump up. I have been keeping track of this because I find it educational to see which posts require special attention.

    As mentioned by Hank Roberts and Susan Anderson, the date and time stamp is sequential like numbers and searchable (the numbers are not searchable). If everybody referred to posts by the time stamp then it is easy to find what is being referred to. Notice how I referred to yours. Highlight the date and time and hit CTRL + F to bring up the find window with the highlighted text in it. Click the up arrow to locate the stamp you are looking at that refers to a previous post. Click the up arrow again to find the original post. Click the down arrow to return to where you were. It’s easy if you know your interface! Why don’t you practice it now?

    Steve

    Comment by Steve Fish — 23 Mar 2013 @ 10:00 AM

  60. Just for the record: for OSX/Firefox: hilight the timestamp; right-mouseclick; View Selection Source; Select (all, or part, YMMV); Copy; Click in the comment; right-mouseclick; Past; annotate ….

    As Steve suggested 23 Mar 2013 at 10:00 AM

    Comment by Hank Roberts — 23 Mar 2013 @ 1:02 PM

  61. To all, on Key Fields:

    Yep, there is a workaround (nearly all bugs have workarounds), though it is not intuitive and to work would require the IMPOSSIBLE scenario where every single user digs through thousands of comments to find Hank’s 60 and then memorizes a sequence of OS/browser specific instructions.

    As a programmer and systems analyst, I know that “what a reasonable user would expect” is the standard, one which should only be violated with Good Cause. So, folks, if ANY of you didn’t first assume the number was an unchanging key [reasonable user], or (you can find a better use for the number than as an unchanging key -OR- its use as an unchanging key would cause some Problem [Good Cause] ), speak up.

    Calling a bug a feature is a classic dodge used by Tightrope Programmers. Myself, I don’t think thousands of users should be required to become highwire experts. Instead, a programer’s JOB is to provide guide rails so users CAN’T make “errors”. Either remove the display of the field (thus promoting/enabling the use of timestamp) or make the field useful. Spending many manhours defending a stupid decision (disclosure: I make just as many stupid decisions as anybody else) “just because” when making the improvement would only take a few minutes, well, that ain’t efficient, eh?

    Reminds me of my programming career. I can’t remember how many times I sat through 3 hour meetings with a dozen people agonizing over whether I would be allowed to do 15 minutes of productive work.

    Comment by Jim Larsen — 23 Mar 2013 @ 4:46 PM

  62. 56 HankR said, “Make clean exhaust without the toxics available, just the CO2 and H20, and I’m sure there will be a great number of uses lining up to capture the stuff. It’s that other stuff in the output that would cost the earth to remove at the point source, they’ll tell you.”

    Good point, though [some folks at] MIT disagrees. They think both the waste heat and the CO2 are up for grabs. I’ve both read a bit on the subject and done experiments using CH4-powered generators. Given that future fossil plants will be CH4 instead of coal, the exhaust won’t be nearly as toxic, but you are absolutely correct that plants aren’t happy breathing fumes, even the relatively clean fumes from a CH4 IC engine. My guess is that’s due to carbon monoxide, though NOx could also be an issue. AFAIK, there are no other significant toxins in CH4 IC exhaust. CH4 turbines are even cleaner.

    In any case, if we’re going to build any more fossil electrical production systems, we HAVE to go way beyond 50% CH4 to CO2 efficiency. (150% might be a reasonable wintertime target – 45% electrical efficiency plus 50% waste heat recovery, plus absorbing much of the resulting CO2) I like the idea of replacing household furnaces and water heaters with cogeneration systems which use the CH4 to BOTH generate electricity AND provide water and space heating, with a miniature version of MIT’s greenhouse system sucking up some of the resulting CO2. The alternative is ground-source-heat-pumps, which have the advantage of automatically transitioning to CO2-free as the grid decarbonizes. And we must remember that choosing any residential or commercial power system locks us into the use of that system for half a century. If the planet can’t take a half century’s worth of the results of our decisions to build, then those decisions are wrong.

    http://web.mit.edu/alamaro/www/GreenhouseConcept.pdf

    http://www.freewatt.com/freewatt_plus.pdf

    Comment by Jim Larsen — 23 Mar 2013 @ 6:21 PM

  63. 62 Jim Larsen: 1. Coal contains: URANIUM and all of the decay products of uranium, ARSENIC, LEAD, MERCURY, Antimony, Cobalt, Nickel, Copper, Selenium, Barium, Fluorine, Silver, Beryllium, Iron, Sulfur, Boron, Titanium, Cadmium, Magnesium, THORIUM, Calcium, Manganese, Vanadium, Chlorine, Aluminum, Chromium, Molybdenum and Zinc. There is so much of these elements in coal that cinders and coal smoke are actually valuable ores.
    http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

    2. Natural gas is certainly cleaner than coal, but it is too late for natural gas to do us any good with respect to GW.

    3. Freewatts aren’t exactly free. An engine is much more complicated/ expensive/ maintenance prone than a furnace.

    Comment by Edward Greisch — 24 Mar 2013 @ 12:13 AM

  64. #62-3:

    Co-generation seems to be a valuable tool in nations where it has been suitably encouraged. Ways of doing that vary:

    http://www.climate.org/publications/Climate%20Alerts/Winter2009/EU.html

    I find the Danish model particularly interesting in that their extensive District Heating grids are now affording them to a tool to help manage the increasing market share of wind: a DH can add an electrode boiler to the plant. At times of high wind output, the electrode boilers can then ‘sink’ a lot of that power to create steam for heating. Grid stabilization and cheap heat at one go–electrode boiler efficiencies are very high.

    It seems unanticipated consequences aren’t always bad ones–this virtue was surely not anticipated when the DH system was being built, back in the 70s.

    To be sure, there are other strategies:

    “The Danish Energy Association report ‘Smart Grid in Denmark’ explicitly acknowledges the central role boilers will play in meeting the needs for intelligent electricity distribution. “A power system featuring demand response [is needed], for example in the form of electric boilers, electric vehicles and heat pumps, so that wind energy can be used when it is available in ample volumes,” the report says.”

    http://www.offshorewind.biz/2013/03/04/norway-boilers-balance-critical-to-renewables-market/

    But there’s something inherently attractive about taking the ‘waste’ out of ‘waste heat,’ however the heat may be initially generated.

    Comment by Kevin McKinney — 24 Mar 2013 @ 7:24 AM

  65. 63:

    Greisch’s Gish Gallop through the unholy elements found in coal neglects to add that the same is true of rocks in general.

    Get used to it- geochemistry happens.

    The Clarke of elemental concentration in the Earth’s crust dictates that all the above have been environmentally ubiquitous
    throughout evolutionary history.

    Comment by Russell — 24 Mar 2013 @ 6:41 PM

  66. To follow my #37, this quotation from the introduction of Hansen et al. (2012) indicates that they are not using models.

    “Although we were motivated in this research by an objective to expose effects of human-made global warming as soon as possible, we use an empirical approach that does not require knowledge of the causes of observed climate change. We also avoid any use of global climate models, instead dealing only with real world data. Moreover, although the location, extent, and duration of regional temperature anomalies is affected by atmospheric blocking situations, El Niños, La Niñas, and other meteorological events, there is no need to understand and analyze the role of these phenomena in our purely empirical approach. Theories for the cause of observed global temperature change are thus separated as an independent matter.”

    Thus, the citation above cannot be correct. As they note in the cited reference, they do have scores of publications on both observations and model analysis. But this one is just on observations. Further, there are attribution papers that use model analysis for individual heatwaves. A list of these would certainly make the point better than citing Hansen et al. (2012) inappropriately.

    Comment by Chris Dudley — 25 Mar 2013 @ 9:17 AM

  67. Russell:

    How many of those “rocks in general” do we make a habit of digging up and burning in large quantities, so that the “unholy elements” are floating around where we can easily breath them in?

    Comment by Bob Loblaw — 25 Mar 2013 @ 9:47 PM

  68. T Marvel #53: I don’t think a 5-sigma test is relevant here. If you bash billions of particles together and get something that could be a random effect, or evidence of a new particle, that’s the scenario where you need very high statistical confidence. Here, we are dealing with observations that fit the theory with measurement techniques with relatively low uncertainty. And we have many independent lines of evidence that point the same way. What we are dealing with here is more like the law of large numbers.

    And in any case, the error in models has consistently over time skewed towards nature being worse than the models. For example, ocean heat content is trending towards greater warming of the deep ocean than predicted, and the amount of Antarctic ice grounded below sea level turns out to be much more than previously thought. What are the odds that those two facts are cause for serious concern?

    Comment by Philip Machanick — 26 Mar 2013 @ 6:44 AM

  69. Bob:

    ‘Rocks in general’ are the stuff of soil and dust,

    The scale on which they naturally weather into respirable particles is such that aeolian transport figures in biogeochemical cycles on transcontinental and transoceanic scales . Explosive vucanism generates stratospheric aerosols, and fumarolic acivity, including hot springs, famously provides a larger mercury flux into the environment than human activity .

    Last but not least, most of the world’s roads are unpaved =, and driving electric vehicles, or riding even horses, over crushed rock inevitably grinds ther rough edges into micron dust. Sextus Empiricus got it right about the mills of the gods grinding eslow but exceeding fine.

    Comment by Russell — 26 Mar 2013 @ 8:21 AM

  70. Russell,
    I take it you are not a fisherman. If you were, you would know that we cannot eat the fish we catch here on the east coast due to Hg and other toxins from the smoke stacks of midwestern coal-fired power plants.

    Comment by Ray Ladbury — 26 Mar 2013 @ 9:37 AM

  71. Ray, I keep a rod up island, where, to tell a fish story , the month after Canada made the limit of mercury detectability the legal limit for fish sold in Canada, a trawler set out from Menemsha late one morning and returned well before sunset loaded to the gunnels with enough fresh swordfish to sustain the Vineyard through the whole 4th of July weekend.

    Watching them land the monster fish, we saw the mate unload as well a pallet of plastic packed smoked salmon, a species of fish seldom caught in these waters.

    Such transactions at sea ended when the Canadians repealed thier draconian legislation in favor of a law with numbers in it, the problem being that between the original bill’s drafting and passage, improvements in mass spectoscopy dropped the limit of detection to parts per trillion, temporarily making all the fish in the world too high in Hg to sell in Canada. Whereupon the Halifax men returned to selling their offshore quota catch to Yankee vacationers in Nova Scotia, instead of their fishermen cousins coastwise.

    The quatitatively illiterate elision of the methyl mercury problem downstream from former chloralakali plants with that from upwind coal emissions in a region whose dentists and crematoria contibute more of a local flux , attests to the power of the press more than geochemical reality – hot springs and vulcanism really do dominate the Hg term.

    I look forward by the way, to the NYTimes, which raises this question annually, around the time of the zuccini glut. siccing its reporter on the free use of cinnabar paint slathered about kitchens with blast furnace woks, to improve the feng shui of restaurants reportly frequented by the editors.

    Comment by Russell — 26 Mar 2013 @ 12:27 PM

  72. Philip,
    There is no more certainty to a 5 sigma result in particle physics than a 2-3 sigma result in most fields. I’ve see 5-sigma results evaporate.

    One may be the loneliest number, but 9s and 0s are the most expensive when it comes to reliability.

    Comment by Ray Ladbury — 26 Mar 2013 @ 12:49 PM

  73. OTOH, I have a duty to caution Ray to shun the Caney Fork of the Tennessee rivers, which drains former zinc minng sites of an Occidental Petroleum subsiduiary, concentrating methylcadmium prodigiously in many delicious creatures , and so putting countless Appalachian citizens at Lord knows what risk?

    David Guggenheim really ought to do a film about it ?

    Comment by Russell — 26 Mar 2013 @ 12:52 PM

  74. @Ray Ladbury #70 “One may be the loneliest number, but 9s and 0s are the most expensive when it comes to reliability.”

    This Delphic utterance deserves at least some elaboration for the benefit of the unwashed (which category I alas inhabit).

    Comment by simon abingdon — 26 Mar 2013 @ 2:38 PM

  75. I would also say to Russell, that the peat environments from coal originates concentrate various elements due to both physical and chemical processes – just like the processes that form zinc concentrations. Noone is saying coal necessarily worse than other mining, but in general mining is an activity we want to minimize where possible.

    Comment by Phil Scadden — 26 Mar 2013 @ 3:15 PM

  76. Simon Abingdon,

    One expresses reliabilities as .9999–4 “nines” of reliability or failure rates as 0.0001. Adding nines and zeros to a system is a costly process. It kinda loses something when you have to ‘splain it. ;-)

    Comment by Ray Ladbury — 26 Mar 2013 @ 4:58 PM

  77. 71 Russell said, “hot springs and vulcanism really do dominate the Hg term.”

    I don’t think so, as:

    http://www.epa.gov/hg/control_emissions/global.htm shows that Mercury emissions around 2002 were 2/3rds anthropogenic.

    Mercury isn’t all the same and Mercury depends on pH. Make surface waters more acidic, and you increase Methylmercury (the harmful kind of Mercury). ” If elemental mercury is ingested, it is absorbed relatively slowly and may pass through the digestive system without causing damage. Ingestion of other common forms of mercury, such as the salt HgCl2, which damages the gastrointestinal tract and causes kidney failure, is unlikely from environmental sources.” http://www.usgs.gov/themes/factsheet/146-00/

    “From pre-industrial times to today, mercury levels in sediments have generally increased by a factor of three.”

    http://www.chem.unep.ch/mercury/Atmospheric_Emissions/UNEP%20SUMMARY%20REPORT%20-%20CORRECTED%20May09%20%20final%20for%20WEB%202008.pdf

    Comment by Jim Larsen — 27 Mar 2013 @ 2:22 AM

  78. > quatitatively illiterate elision

    Hey, that’s the name of my new band!

    “Methylmercury is the only form of mercury that biomagnifies in the food web. Concentrations of methylmercury in fish are generally on the order of a million times the methylmercury concentration in water.” http://www.epa.gov/mercury/executivesummary.htm

    Look what the fishing industry calls ‘sustainable swordfish’ — itty bitty fish, probably not even reproductively mature; if they don’t get a few decades to reproduce, how’s a population sustainable? Of course it hasn’t had much time to accumulate the crap that bioaccumulates. Remember, 90 percent of the big fish are gone. Look at the swordfish here page down — a ways to see it.

    Comment by Hank Roberts — 27 Mar 2013 @ 10:58 AM

  79. Aside, from that last (mostly swordfish) PDF link I posted above, this:

    ——–excerpt

    “… there is remarkable consistency in the history of resource exploitation.
    We suggest that such consistency is in part due to the following:
    Large levels of natural variability mask effects of overexploitation.
    Thus, initial overexploitation is not detectable until it is severe …”
    — Uncertainty, Resource Exploitation, and Conservation:
    — Lessons from History (Ludwig et al. 1993)
    Furthermore… sliding baselines influence our attitutes towards nature

    ——–end excerpt—-

    That describes treating climate as a resource (a resource that was assumed to be limitless, like the forest, buffalo, whales, and ozone layer)
    — natural variability masks the effects of overexploitation … until it is severe …

    Comment by Hank Roberts — 27 Mar 2013 @ 3:06 PM

  80. Ya know, this ought to be “Climate Change and Consequences on the Ground, in the Air, and in and over the oceans ….”

    We’re currently harvesting krill to feed people and whatever else they’re doing with it — competing with the reduced number of whales and other filter and plankton feeders.

    What if …. some plankton is more equal than others?

    Will we see PR, papers, and eventually ads from AgriGlob promoting the new Roundmeup-responsive farmable plankton — so superior to all those other wild type planktons that dosing the Southern Ocean with Roundmeup — treating the ocean like a factory farm state — is clearly the only next thing to do.

    Seriously, consequences in addition to those “on the ground” need attention. Think of your old mother, will you?

    Comment by Hank Roberts — 27 Mar 2013 @ 7:37 PM

  81. Thanks, Hank. It’s also important to remember that bigger fish eat smaller fish. Thus, small fish eat baby swordfish and bluefin tuna by the millions. This is naturally limited by adult swordfish and tuna eating small fish. Remove most of the adults, and the percentage of babies that survive to adulthood will decline as other species, especially those not fished for, scarf up baby tuna. (Thus opening up the “solution” of vacuuming the ocean to eliminate all those “baby-killers”)

    Then there’s the size limits. I’ve long pondered that size limits might be backwards. Instead of saying that small swordfish must be thrown back, throw back all large swordfish. That a particular female lives long enough to lay her first tiny batch of eggs is feel-good, but seems scientifically irrelevant. Your link said, “Reproduction:Females produce variable number of eggs: from 1-16 million in a 370-pound female to 29 million in a 600-pound female”

    Thus, harvesting a 600lb swordfish is probably more harmful than harvesting two 300-pounders or ten sixty-pounders. IIRC the Maine lobster fishery has taken this into account by having a maximum harvestable size. (I couldn’t find any info on swordfish maximum lifespan, just that it’s at least 12 years. Lobsters have no maximum lifespan, so the comparison might be flawed)

    When the average size harvested is less than 1/3 the effective reproductive size even when we’re trying our hardest to catch the (more valuable) biggest fish (if the link’s numbers and my simplistic interpretation are correct), Houston, we have a Problem.

    Your link was a bit frustrating. It listed the Official Position, that swordfish fishing became “perfect” for the available biomass by 2009, then almost started down a path of refutation by mentioning age at harvesting, but immediately took a strange turn into talking about Kansas and roller coasters.

    My band’s name would be Hot Shade.

    Comment by Jim Larsen — 27 Mar 2013 @ 10:07 PM

  82. 79 HankR quoted, ” natural variability masks the effects of overexploitation … until it is severe …”

    Yeah, but in the case of fishing, I think that effect is less important than human desire and ability. We remember the pounds caught last decade and will ponder and think and improve so as to ensure we catch at least as much next decade. That the effort (measured in horsepower-hours, not man-hours) goes up by a sigma (see unforced variations) is irrelevant other than as a price determinant.

    But in reality, if effort goes up by a factor of 10, then the simplistic no-other-knowledge conclusion is that the resource has declined by a similar factor. If you want to measure the health of the (insert species here) fishery, go out in old boats with old routes and old tackle. See what you catch, and compare it to what a similar boat brought back in 1800 or 1920 or whenever.

    So yes, we can send more and more bigger and bigger boats out and maintain the harvest. Until we can’t.

    Comment by Jim Larsen — 28 Mar 2013 @ 2:06 PM

  83. 76 RayL said, “One expresses reliabilities as .9999–4 “nines” of reliability or failure rates as 0.0001. Adding nines and zeros to a system is a costly process. It kinda loses something when you have to ‘splain it. ;-)”

    Being a natural fool who’s attracted to such challenges, I’ll waste some bandwidth!

    The easiest explanation is money. Full time minimum wage is $15k. Become a basic doctor and you’re a mere ONE sigma higher at $150k.

    Learn to suck up Other People’s Money on Wall Street, and you MIGHT get ONE sigma higher at $1.5 mil.

    Become a Ruler of the Universe and you’ll rake in $15 mil a year. ONE sigma.

    So here we are, a mere three sigma above pure-t-failure.

    Now, figure out the effort/luck/evil/good/whatever it would take to get to 4 sigma on the human income scale….

    Comment by Jim Larsen — 28 Mar 2013 @ 2:54 PM

  84. Re- Comment by Jim Larsen — 28 Mar 2013 @ 2:54 PM

    You are confusing orders of magnitude with standard deviation.

    Steve

    Comment by Steve Fish — 28 Mar 2013 @ 5:03 PM

  85. 77 that’s not right , Jim

    Look at the numbers in the link you provide and you will find that the annual natural atmospheric flux of Hg is estimated to be, on average, some 1,200 tonnes greater globally than the anthropogenic flux, re-emissions included.

    While it is cautionary that there is a roughly threefold uncertainty in both sets of estimates , the North American natural flux exceeds that from coal combustion in the Midwest roughly an order of magnitude

    Comment by Russell — 28 Mar 2013 @ 5:31 PM

  86. #83-Jim, a good simile, but I’ve got to say that mere Ruler of the Pop Charts can pull $15 mil–and Dr. Dre is reportedly pushing toward 4 sigma at $110 mil. Just sayin.’

    Comment by Kevin McKinney — 28 Mar 2013 @ 7:09 PM

  87. > on average
    >> methylmercury

    And on average, no worries to speak of. It’s those pesky food chains …

    Comment by Hank Roberts — 28 Mar 2013 @ 8:14 PM

  88. Kevin McKinney, Don’t forget the Hunts, who went from bankruptcy awhile back over their silver fiasco, to billionaires just recently by selling some Bakken fracking land, how many sigma is that? ;)

    Comment by flxible — 28 Mar 2013 @ 10:28 PM

  89. 84 SteveFish, oops, you’re right and thanks. My muddled mind now says that using the word “sigma” was wrong. We’re talking 9s and 0s, as in orders of magnitude. The visual should still work if one substitutes the correct words.

    85 Russell, are you talking about the chart on page 13? It (using first column/estimate) shows total natural emissions from land and ocean (I assume volcanoes et al would be included based on where they are?) to be 1.4kt, and total emissions to be 4.4kt, so I’m confused as to what you’re saying. And the sediment data sure seems like the Gold Standard. Measuring fluxes is HARD and subject to tremendous error, but digging a core and measuring mercury is just standard science….

    Comment by Jim Larsen — 28 Mar 2013 @ 11:12 PM

  90. What I get from rasmus’s article is that the link between global warming and extreme weather remains uncertain, but concludes with a precautionary approach in “better safe than sorry”.

    This weak link is in line with the conclusions of the IPCC SREX report (2012). But it is in contrast to many other messages we get – from Al Gore, James Hansen, the film Greedy Lying Bastards, etc.

    The “elegant example” of Petroukhov et al 2013 doesn’t provide any strong conclusions with its Abstract using phrases like “Here, we propose a common mechanism …”, “We show that these patterns might result from…” and “Such midlatitude waveguides, however, may favor…”.

    This demonstrates to me that the debate on whether extreme events can be linked to global warming / climate change remains wide open.

    What would be concerning is if the intention were to ‘keep looking until we find the link’, whereas an equally viable conclusion could be ‘we’ve looked but conclude there is no clear link’.

    Comment by Quercetum — 29 Mar 2013 @ 2:42 AM

  91. Quercetum,
    I would say that the mechanisms of linkage are fields of active research. However, data clearly show increased drought, increasing heat waves and, with less certainty, increased impulsive precipitation events. No single event is climate. Climate can load the dice to favor some extremes more than others. That is quite consistent with what Hansen et al. are saying.

    Comment by Ray Ladbury — 29 Mar 2013 @ 8:29 AM

  92. So has the warming slowed down over the last decade as this article suggests? http://www.climatecentral.org/news/why-the-globe-hasnt-warmed-much-for-the-past-decade-15788

    Thoughts?

    Comment by Chuck Hughes — 29 Mar 2013 @ 9:08 AM

  93. Jim Larsen #81: I went to a talk by an expert on marine ecology and your point is pretty much on the money. A small fraction of baby fish survive to add to the gene pool; each adult fish has made it despite all manner of obstacles, and represents a huge investment. Taking out one fully grown adult fish is generally a much higher cost to the environment than its weight in juveniles.

    Comment by Philip Machanick — 29 Mar 2013 @ 9:39 AM

  94. > Quercetum … what I get … weak link … the debate …

    Nah. You’re comparing PR language to scientific journal language as though they were being used in the same conversation, and getting doubt and skepticism reinforced because the journals aren’t using the PR language. They won’t.

    The PR will always be definite! conclusive! punchy!! headline-grabbing, by intent.

    What’s the world telling us? Looked at this? http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/03/28/incredible-storm-spans-atlantic-ocean-coast-to-coast/?tid=pm_pop

    How often do you see a March storm this big, moving as slowly as this one is?
    A bit of atmospheric blocking, perhaps, at work here?

    Comment by Hank Roberts — 29 Mar 2013 @ 9:59 AM

  95. Dammit! There is a metric shite-ton of weapons grade stupid in the comments section of that Economist article.

    Comment by Ray Ladbury — 29 Mar 2013 @ 11:20 AM

  96. > Chuck Hughes says … So has the warming slowed down over the last decade
    > as this article suggests?

    Be careful about “the warming” — that’s not about global warming, it’s about air temperature.

    The article says that particular measure/graph shows slower increase, and asks where the heat could be going that doesn’t show up in that measure.

    The article explains that the deep ocean water change isn’t in that chart; it says the heat may be going there, for a while, referencing:
    http://onlinelibrary.wiley.com/doi/10.1002/grl.50382/abstract

    Comment by Hank Roberts — 29 Mar 2013 @ 12:50 PM

  97. #90–“What would be concerning is if the intention were to ‘keep looking until we find the link’, whereas an equally viable conclusion could be ‘we’ve looked but conclude there is no clear link’.”

    A lot less concerning than if the intention were to give up looking because looking is hard work or something–with large practical consequences potentially on the line, ‘equally viable conclusions’ is just another term for ‘uncertainty.’

    Luckily, giving up looking at this point is about probability zero.

    Comment by Kevin McKinney — 29 Mar 2013 @ 3:26 PM

  98. On the other hand: http://www.colorado.edu/news/releases/2013/03/01/volcanic-aerosols-not-pollutants-tamped-down-recent-earth-warming-says-cu

    Comment by Hank Roberts — 29 Mar 2013 @ 3:30 PM

  99. Jim Larsen says:
    27 Mar 2013 at 10:07 PM
    Thanks, Hank. It’s also important to remember that bigger fish eat smaller fish. Thus, small fish eat baby swordfish and bluefin tuna by the millions. This is naturally limited by adult swordfish and tuna eating small fish. Remove most of the adults, and the percentage of babies that survive to adulthood will decline as other species, especially those not fished for, scarf up baby tuna. (Thus opening up the “solution” of vacuuming the ocean to eliminate all those “baby-killers”)

    Then there’s the size limits. I’ve long pondered that size limits might be backwards. Instead of saying that small swordfish must be thrown back, throw back all large swordfish. That a particular female lives long enough to lay her first tiny batch of eggs is feel-good, but seems scientifically irrelevant. Your link said, “Reproduction:Females produce variable number of eggs: from 1-16 million in a 370-pound female to 29 million in a 600-pound female”
    What you describe are slot limits which are frequently used for that very reason. Bluefin tuna have different regulations for different size classes for example:

    Comment by Phil. — 29 Mar 2013 @ 6:20 PM

  100. 87
    Hank, the point in this region is that most of the mercury those pesky bacteria convert into the methylmercury that those pesky food chains concentrate comes from natural sources, not smokestacks, and that the preindustrial flux, and attendent food chain toxicity issues, were accordingly of the same magnitude as today’s

    Whole valleys in epithermal volcanic areas of Melanesia and NZ are tapu to hunters because the locals have realized their fauna are charged with drop dead heavy metal levels- one Kiwi hot spring gained Victorian fame for depositing mirrorlike deposits of mercury on iron shovels stuck in the ground nearby.

    Comment by Russell — 29 Mar 2013 @ 7:08 PM

  101. Wait — is there evidence that food chains haven’t accumulated any more mercury than they did before coal-burning started?

    Where can I read about this, and what else have they lied to me about?

    Comment by Hank Roberts — 29 Mar 2013 @ 7:55 PM

  102. Also for Chuck Hughes, this climate blogger writes well about how to learn:
    http://angusferraro.wordpress.com/2013/03/29/new-chapters-and-foreign-lands/

    “… In order to interpret my model results I had to learn to thinking differently. Intuitions learned from midlatitude dynamics don’t apply this close to the Equator.

    “Learning new theory can be pretty intimidating. It’s difficult to know which paper to read first. Sometimes I find myself feeling paralysed. I have a pile of things to read but keep having to refer to different sources to understand terminology, or to get to the bottom of some ‘obvious’ physical understanding not fully explained in one piece of research….”

    Comment by Hank Roberts — 29 Mar 2013 @ 8:44 PM

  103. 100 Russell, you HAVE to start giving some sort of evidence. NOTHING posted here shows natural sources are more than a minor component totalling the least harmful 1/3 of Hg emissions. To REFUSE to provide ANY evidence yet bleat that “it’s all natural”, well, it gets frustrating for the rest of us, and we tend to slot “Russell” into the “Fool” bin. (sorry, tis just human nature). Much better would be to actually provide some data or logic, eh? Show us why our initial response was wrong. I’m rooting for ya, kid.

    Comment by Jim Larsen — 29 Mar 2013 @ 10:07 PM

  104. and Russell, by ANY evidence, I mean just that. So far you’ve shown ZERO. So, to buttress your case, ANY thoughts by ANYBODY would suffice. So, troll the web, find ANYBODY who would benefit financially or mentally, and share.

    My guess is you’ll waste a week finding bubkis.

    Comment by Jim Larsen — 29 Mar 2013 @ 10:38 PM

  105. https://en.wikipedia.org/wiki/File:Mercury_fremont_ice_core.png

    Comment by Hank Roberts — 30 Mar 2013 @ 11:22 AM

  106. Thanks Hank. Very accessible visual, and fascinating. Hope that stops the yelling and shows that life is complex. We already knew that, but somehow the anti-science contingent always wants to fasten on absolutes (and no, I’m not talking to you, if you think this was addressed to you, most likely).

    Comment by Susan Anderson — 30 Mar 2013 @ 7:58 PM

  107. 103, 104

    The evidence Jim Larsen demanded on 29 March is contained in the very link he provided , but evidently has not troubled to read in full, which gives the range of estimates for both natural and anthropogenic Hg fluxes. If he finds that data hard to deconvolute, he may be in for a shock when he encounters the primary geochemical literature.

    He appears to be comparing the lower outliers instead of the average figures, let alone the higher ones- He will find the ice core record useful in comparing the continuous threat posed by volcanic and hot spring emissions with such intensive but sporadic local fluxes as those associated with the California gold rush and silver mining in Mexico and Bolivia, but the op-ed unfriendly fact remains that the average estimate of the annual natural flux is 1,230 tonnes larger than the average of the antropogenic flux estimates : geochemistry happens.

    Comment by Russell — 1 Apr 2013 @ 2:55 PM

  108. Re- Comment by Russell — 1 Apr 2013 @ 2:55 PM

    I am compelled to inform you that Jim Larsen is also in denial of Easter bunny abuse.

    Steve

    Comment by Steve Fish — 2 Apr 2013 @ 10:51 AM

  109. 107 Russell,

    Thanks for the hint, but I’m a tad old to hunt for Easter eggs. I tried to get you to post a direct link and easy instructions or maybe even a quote, but you still hide behind words without backing. So, yep, I’d love to engage you in your wild claim, but you STILL refuse to provide any information.

    As to my looking at the charts and whatnot, I abide by an absolute no-cherry-picking rule. Either I accept the “opponent’s” data, or I look at data not chosen for values. Thus, I posted the FIRST column and perused the others to see if it was an outlier. Since you’re saying that data is flawed even though it matches every other source I found, well, go for it kid. Show us the REAL data, including links and quotes. After all, if I ain’t smart enough to find this Cherry in a haystack, surely others will fail as well. Enlighten us.

    At least some information, please. Thanks.

    Hopefully my next post will begin with, “Well, lookie there!”

    Comment by Jim Larsen — 2 Apr 2013 @ 12:53 PM

  110. 108 Steve Fish, I plead the 5th, and to insinuate that has anything to do with my denial, well, that’s unconstitutional.

    Comment by Jim Larsen — 2 Apr 2013 @ 1:11 PM

  111. 109:

    There is hope if you can get the level of your cherry-finding up to the level of your cherry picking.

    Comment by Russell — 2 Apr 2013 @ 6:57 PM

  112. Re- Comment by Jim Larsen — 2 Apr 2013 @ 1:11 PM

    I presume you have checked out Russell’s web site. If not, you can learn the truth about who ate the Easter bunny by clicking his name.

    Steve

    Comment by Steve Fish — 2 Apr 2013 @ 7:13 PM

  113. Getting back to the original topic, L. A. Times article
    “Climate change will increase extreme precipitation levels”
    http://www.latimes.com/news/science/sciencenow/la-sci-sn-climate-change-extreme-precipitation-20130404,0,125887.story

    One of the commenters points out the U.S. Climate Extremes Index (CEI) pages
    http://www.ncdc.noaa.gov/extremes/cei/graph/4/01-12 and wonders whether somebody has tried to determine correlations between extreme precipitation for example and temperature. Any takers?

    Comment by AIC — 7 Apr 2013 @ 4:00 AM

  114. Re: precip-T relations

    Mueller and Seneviratne,PNAS,2012
    http://www.pnas.org/cgi/doi/10.1073/pnas.1204330109

    sidd

    Comment by sidd — 7 Apr 2013 @ 11:11 AM

  115. Thanks, sidd.

    I was especially looking for the correlation (and presumably causation) relationship of increased temperatures causing extreme precipitation, but that may well need some very detailed looking at what was happening just before/upwind of each particular extreme precipitation event.

    Comment by AIC — 7 Apr 2013 @ 4:19 PM

  116. GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L17707, doi:10.1029/2012GL052762, 2012, How much do precipitation extremes change in a warming climate?
    Chein-Jung Shiu, Shaw Chen Liu, Congbin Fu, Aiguo Dai, and Ying Sun
    “Daily data from reanalyses of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) are analyzed to study changes in precipitation intensity with respect to global mean temperature. The results are in good agreement with those derived from the Global Precipitation Climatology Project (GPCP) data by Liu et al. (2009), providing an independent verification for large changes in the precipitation extremes: about 100% increase for the annual top 10% heavy precipitation and about 20% decrease for the light and moderate precipitation for one degree warming in the global temperature.”

    Comment by Brian Dodge — 7 Apr 2013 @ 9:41 PM

  117. Re Comments above on Precipitation

    I think it’s actually a lot easier to understand changes in the extreme precipitation events than it mean changes (contrast this to the robustness of global temperature predictions for the mean vs. extreme events).

    For extreme precipitation events, the upper bound on atmospheric water vapor in regions of convergence plays a significant role (I believe Issac Held has a post on this). This is all well-defined by the Clausius-Clapeyron equation. In contrast, Clausius-Clapeyron doesn’t tell you much about mean changes in rainfall because precipitation is generally energetically limited rather than moisture limited. That makes it critical to understand the energy budgets of the surface or troposphere, including the temperature differential between the surface and boundary layer.

    In fact, there’s very little use in speaking of a precipitation-temperature slope, dP/dT, without a detailed consideration of the forcing agents involved, etc. Precipitation can very well decline in a warming climate, in contrast to the column water vapor amount, which is virtually always monotonically increasing. The latter, I believe, will be more relevant when thinking about the (extreme) tail end of a PDF of precipitation events.

    Comment by Chris Colose — 7 Apr 2013 @ 10:14 PM

  118. Re:precip-T relation

    there are gridded data for temp and precip but i think only down to 1 or 2.5 degree lat/long, and quikscat or somesuch will give you the winds

    talk to these guys, they probly have ideas

    http://earthobservatory.nasa.gov/Newsroom/view.php?id=22473

    sidd

    Comment by sidd — 7 Apr 2013 @ 11:52 PM

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