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Comments 58351 to 58400:

58351. Composer99 at 15:33 PM on 30 May 2012
       Models are unreliable
       Clyde, you appear to be attempting to make a case against climate science (or at least, echoing Dr Pielke Sr's case) on the basis of its use of computer models to project future states of the climate. This is likely to be an exercise in futility on your part. As I intimated on the Bob Carter thread, the mainstream scientific position on climate is the result of an intertwining web of: (1) Physics & chemistry theory (ranging from quantum-mechanic radiative properties of IR-trapping gases, to the physics of blackbodies, to the chemistry of ocean buffering of CO2, to many other strands of theory besides); (2) Lab or computer experiment (starting with Tyndall's experiments demonstrating the atmospheric IR-trapping gases and confirming the atmospheric IR-trapping 'greenhouse' effect all the way to the elaborate atmosphere-ocean-surface coupled models of the present); (3) Empirical observation (the surface, satellite & sea surface temperature datasets, measured ocean heat content, measured crysophere melt, shifting wind currents & atmospheric cells, shifting animal & plant distribution, and so on). It it this intertwining of these various strands of evidence which has led to the formation of the generally-accepted scientific consensus on climate change, as expressed by the IPCC, the US NAS, the UK Royal Society, and virtually every major national, transnational, or intranational scientific organization. Even supposing you could chip away at the reliability & accuracy of computer models, you would still have an enormous task ahead of you to knock down enough of the theory, experiment & observation supporting the mainstream consensus to cause a substantial re-think.
58352. scaddenp at 14:44 PM on 30 May 2012
       Models are unreliable
       Just on the RC discussion you might like to look at this comment and surrounding context.
58353. Bob Loblaw at 14:41 PM on 30 May 2012
       Models are unreliable
       Last comment for now... Clyde: if you want to see why the name of Pielke Sr. gets the reaction it does here, read the discussions available here, where he has participated in some comment threads, and there have been numerous blog posts commenting on his arguments. Note that Pielke Sr. does not seem to allow comments at his own blog, so it isn't easy to engage in a discussion with him about them. I've already done some searching for you (the search box is in the upper left corner of the SkS page). You can try reading these blog posts and discussions: Pielke Sr and scientific equivocation: don't beat around the bush, Roger Response to Roger Pielke Sr. One-Sided 'Skepticism' Chasing Pielke's Goodyear Blimp SkS Responses to Pielke Sr. Questions Pielke Sr. Agrees with SkS on Reducing Carbon Emissions Pielke Sr. and SkS Disagreements and Open Questions Pielke Sr. and SkS Warming Estimates Pielke Sr. and SkS Dialogue Final Summary Pielke Sr. Misinforms High School Students
       Moderator Response: (Rob P) Removed dead link
58354. Bob Loblaw at 14:22 PM on 30 May 2012
       Models are unreliable
       Clyde: you said "I know enough to understand a failed prediction. Do you want me to post the links to the failed predictions/projections? Please do so, but keep in mind that here at SkS you will be expected to back your position up with references to real scientific literature (not just blog posts). Before you start to post your own stuff, though, you may want to review the series of posts found using the Lessons from Predictions search item. There is a button that will do this search for you near the top left of the SkS page (just above "Most Used Climate Myths").
58355. Bob Loblaw at 14:13 PM on 30 May 2012
       Models are unreliable
       Clyde: What is your definition of a "computer modeler"? On what basis do you claim that any particular "climatology expert" is not knowledgeable about computer modeling, and how would this affect the work that they are doing? I think that you are creating a strawman "computer modeling expert", in a futile attempt to pretend that climatologists can't do "computer modeling". Many climate modelers have physics and mathematics in their background, and at least one I know personally works in a mathematics department. I would consider myself to be a "climatologist", and I have written "climate models" (microclimate) from scratch. My background is physical geography, but - I have studied numerical methods, including finite difference solutions to partial differential equations. - I have coded numerical solutions to radiative transfer, atmospheric turbulent heat transfer, and soil thermal diffusion problems. - I know from study and experience the issues related to floating-point arithmetic, and how to avoid them. - I have coded the required root-finding procedures for complex, non-linear systems. - I wrote my first computer program before I took my first computer course, and before most people had a clue what "Computer Science" was (or would be). I never took a second computer course, but I have written serious code in three different languages, simple code in a few more, and can read read quite a few more than that. And I know that "Computer Science" students often don't get exposed to half the stuff that I have learned that is necessary to do "climate modeling" correctly. - my first numerical programming was done on punch cards, fed into a mainframe computer. I've been doing programing for almost 35 years. What else would I need in my background to convince you that I know enough about "computer modeling"? I seemed to convince my PhD thesis examining board that the modeling work I did was valid - and that board included an engineer that asked me why I used a secant root finding method instead of Newton-Raphson, and a physicist that said that when he read my thesis he discovered a field of study that he could have been very happy doing instead of physics. I agree that the science is above your head. It doesn't have to stay that way if you are willing to learn. Start by giving me your definition of "computer modeler", and what makes you think that people doing climatology aren't capable of it...
58356. scaddenp at 14:04 PM on 30 May 2012
       Models are unreliable
       Clyde, what on earth makes you think modelling teams dont include heavy-duty modelling folk? As to "failed predictions" that pick up off blogs, there are a couple of things to check. First, check the source of the prediction. The usual denialist stuff is make claims about a prediction that are not actually made and since its a straw man, (take note of error bars) then its easy to demolish. All models are wrong, but some predictions are far more robust than others. A converse page of robust model predictions together with papers that do the prediction and papers that confirm it can be found here Second, modellers usually judge models by skill. Ie the ability of models to make better predictions than some simpler method (ie that nothing is changing). Climate models have no skill for instance at decadal-level predictions. This is common "skeptic" ploy. As to Piekle, perhaps you should follow the discussion with the modellers at Realclimate? In short, you cannot make naive comparisons of models and observations. If you still think there is clear case of model "being wrong" supported by papers, then by all means post links.
58357. muoncounter at 13:26 PM on 30 May 2012
       Models are unreliable
       "heart surgery done ... by a doctor who has used a computer to project/predict how to do the operation?" What nonsense. Medicine uses computer imaging, based on models of how the body interacts with magnetic fields, sound and/or radiation. Oil exploration uses computer modeling based on seismic techniques. Is there a car or airplane that can function without a computer? Why is climate science held to the false standard that 'computer models don't work'? "You can input all the physics & chemistry you want into a computer. Doesn't mean what comes out is accurate." No, but it does mean that we can eliminate things that can't be verified by models. We can eliminate the idea that climate change is purely natural.
58358. michael sweet at 13:05 PM on 30 May 2012
       Renewables can't provide baseload power
       curiousd, You would need a new grid to transmit the energy efficiently. It is hard to imagine that they would follow a rational design in the USA instead of choosing a series of short term fixes. I have heard that DC might be more efficient but would have greater political issues. If people want it to work bad enough they can make it work. For what the Iraq war cost you could build a new grid and build enough solar to power the whole country. (and still have money left over). People have to decide it is worth the effort.
58359. Clyde at 13:00 PM on 30 May 2012
       Models are unreliable
       Jim Eager 506# I've never seen any credit given to computer modelers. Would you want heart surgery done by a doctor who has performed say 100 successful operations or by a doctor who has used a computer to project/predict how to do the operation? Would you bet your life on the future global warming projections/predictions coming from computers? I read a few other blogs. As i said earlier the science is above my head. I know enough to understand a failed prediction. Do you want me to post the links to the failed predictions/projections? From my brief time of reading this blog Rodger Pielke Sr is not one of the favorites around here. Why doesn't somebody ( you if your qualified) refute his claims on climate model predictions/projections? I'm not saying Rodger is right or wrong. He has an open challenge to prove him wrong & nobody has taken him up on it. He admits when he is wrong. He had to eat crow after a discussion he had with dana1981. You can input all the physics & chemistry you want into a computer. Doesn't mean what comes out is accurate. Have a nice day
58360. Jim Eager at 10:11 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       And 3) My totally uninformed opinion is just as valid and worthy of equal consideration as your highly informed and hard-won expertise, if not more so.
58361. Bob Lacatena at 09:51 AM on 30 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       34, Steve, But choosing 1900 is a convenient cherry pick, because it obscures the effects of AGW, which are known to have really taken hold in the 1970s, with other climate events. In fact, if you look at the data you can very clearly see that rainfall increased in the first half of the century. 32, Tom, Your points are valid, except that: 1) If they computed proper trends then the impact of an early event like that is not going to impact the curve as strongly. You can also, if you prefer, go from 1950 forward: 2) You can not necessarily say that all warming is equivalent. In particular, the changes in rainfall patterns have a lot to do with the expansion of the Hadley Cells and the movement of the ITCZ. Admittedly, greater evaporation has something to do with it, but even that doesn't say anything about where the rain will fall. We had a discussion similar to this one about the Texas drought, and Australia is the flip side of the coin. Here is a diagram of the expansion and poleward movement of the Hadley cell in the Southern Hemisphere. This may well be responsible, now or in time, for adding more seasonal rainfall to the north and drying out the rest of the continent. From Observed poleward expansion of the Hadley circulation since 1979 – Hu & Fu (2007): The ITCZ from various sources:
58362. Tom Curtis at 09:35 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       vroomie @35:

       "I'm a geologist, dagnabit, *not* a computer expert"

       You are forgetting the first axiom of denier's (and unfortunately that of too many elements of the media) that: 1) If you are expert in any subject, you are an expert in every subject in which you agree with my opinion. The second axiom is: 2) If you are an expert in a particular subject, if I disagree with you on that particular subject your stated opinions are based on fraud and conspiracy.
58363. vrooomie at 09:10 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Clyde@7, you ask: "Why is it that folks who critique AGW are dismissed if their not experts in climate science, but we should just accept a climate scientist's work on models when their not experts in computer modeling?" The reasons are vasried, well-documented, and are scientifically rigorous, as to why so-called "fake" experts are robustly, and rightly, questioned. To paraphrase another user here at SkS, you cannot believe just one scientist; you CAN, however, believe thousands. And at this time, many thousands who are bona fide experts in all the subjects relevant to AGW share a consensus, a consensus which is *vehemently* opposed by those who don't have the chops to refute that consensus. DB@19: Thank you fro correcting my bad "Netiquette." I'm still learning all this modern-fangled computer, HTTP stuff. I'm a geologist, dagnabit, *not* a computer expert...>;-D
58364. adavid at 08:45 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Jim and Tom good catch. It would have been better for me to have written "the influence of the sun on global temperatures peaked 10,000 years ago".
58365. Tom Curtis at 07:49 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       adavid @30, solar radiation has been close to constant, with variations of well less than 1% over the last 10,000 years. What peaked about 12 thousand years ago was Northern Hemisphere summer insolation. Because this peak was due to the orientation of the Earth to the Sun, it made little difference to the Earth's total insolation.
58366. Jim Eager at 07:28 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Adavid, that would be orbitally driven northern high latitude summer insolation that peaked 10,000 years ago. What's more relevant for the current warming is that since ~1980 there has been no correlation between change in insolation and rising global mean temperature.
58367. Jim Eager at 07:15 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       In other words, Clyde has no evidence what so ever, only conjecture and assumption. A question for you, Clyde: Which would you find more believable as a climate modeler, a climate scientist, or rather team of scientists, who are also competent at building a computer model of the physics and chemistry of the coupled land-ocean-atmosphere system, or an expert at computer modeling who knows absolutely nothing about the underlying physics and chemistry of the coupled land-ocean-atmosphere system that is being modeled? (Why should they, they are not climate scientists, they're computer modelers, while practically all physical scientists work intensively with computers.) And why did you fail to consider that climate scientists work with actual computer modelers when developing climate models, as I suggested, before leaping to defend your assertion that climate scientists have no expertise in the use of computers? Also posted here in case Clyde want's to continue to defend his misconceptions.
58368. Jim Eager at 07:15 AM on 30 May 2012
       Models are unreliable
       Continued from here In other words, Clyde has no evidence what so ever, only conjecture and assumption. A question for you, Clyde: Which would you find more believable as a climate modeler, a climate scientist, or rather team of scientists, who are also competent at building a computer model of the physics and chemistry of the coupled land-ocean-atmosphere system, or an expert at computer modeling who knows absolutely nothing about the underlying physics and chemistry of the coupled land-ocean-atmosphere system that is being modeled? (Why should they, they are not climate scientists, they're computer modelers, while practically all physical scientists work intensively with computers.) And why did you fail to consider that climate scientists work with actual computer modelers when developing climate models, as I suggested, before leaping to defend your assertion that climate scientists have no expertise in the use of computers?
58369. adavid at 06:48 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Bob Carter first referred to himself as a Palaeoclimatologist in his book "Climate: The Counter-Consensus". Apart from a brief mention of peering at ocean sediment cores, there was no reference to any of his geological work in that book. The glaring oversight to me is mentioning the sun with respect to recent warming. Any palaeoclimatologist knows that incoming solar radiation peaked 10,000 years ago.
58370. john byatt at 06:46 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Apologies for using URL, too much time at RC
58371. john byatt at 06:17 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Tom Wigley, Uni Adelaide Switching from coal to methane would slightly increase global warming until 2050 or longer http://www.sciencedaily.com/releases/2011/09/110908124505.htm
       Moderator Response: TC: Link connected.
58372. bath_ed at 06:04 AM on 30 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Back to the topic at hand - the many unique plants of the winter-rainfall zones of South Africa and Australia and the effect on them of a possible southerly retreat of the rain-bearing westerlies - it will be of no comfort to them if rainfall increases in other climatic zones. The endemic plants of the Cape aren't going to derive any benefit if the Lowveld or Kalahari etc get wetter and neither will the plants of south-west Australia suddenly move to the tropical savannas and semi-deserts of the north. I think this illustrates the problems of glib, sweeping contrarian statements such as 'a warmer world is a wetter world' which may be true in a very general sense but are used to distract from the specific problems different regions, ecosystems and species face. A small point: the rainfall maps of Australia and South Africa have a significant difference in that the Australia one separates out the arid zones and the South Africa one doesn't - only the far southwest of the winter rainfall zone is relatively well-watered; the north especially (such as the RSA/Namibia border) is fully arid, just what little rain it gets falls mainly in the winter half of the year. Therefore rain-fed crops and many plant species are restricted to only the southwest.
58373. Andy Skuce at 05:55 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       BWTrainer: The IEA estimates are explicitly for CO2 emissions from fossil-fuel combustion. The non-combusted fugitive methane emissions from natural gas production would not therefore be included. The conclusions of Howarth et al have been disputed by other Cornell researchers, in which they claim that the Howarth study: assumed a very high estimate for methane leakage; compared heat rather than electrical energy generation, (favouring coal); and used a short time period that did not sufficiently take into account the long term effects of CO2 compared to methane emissions.
58374. IanC at 05:45 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Clyde, Climate modelling involves writing down a set of equations to describe the underlying physics of the climate system, and then solve the resulting set of equations to give you a numerical answer. Computers are nothing more than a tool for number crunching. In short, a climate modeller will have to be an expert, by default, in whatever programming language they work in, just as a image designer must be proficient with photoshop, a writer must be proficient with the language. One only needs to know how to get the computer to compute 1+1, not necessarily how the computer arrives at the answer.
58375. dana1981 at 05:25 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Clyde - all future predictions about everything are based on models. If I drop a coin off a bridge and calculate how long it will take to reach the ground, I'm using a model. That model, like climate models, is based on fundamental physical laws. Also, all models are "wrong," including the one in my simple example. No model is perfect, but models can be useful tools - climate models certainly are (i.e. see here). As for your modelers question, I still don't understand what you're asking. My point was that scientists don't necessarily have to be modeling experts to use a climate model (depending on what they're using it for). Regardless you seem to think models play a much bigger role in climate science than they actually do (i.e. see Rob H's comment #27).
58376. dana1981 at 05:10 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       BWTrainer - the IPCC scenarios consider non-CO2 GHGs separately, so we would have to compare observed methane emissions to the emissions in their scenarios to see where we're at.
58377. Rob Honeycutt at 04:35 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Clyde @ 25... No, all future predictions/projections are not just based on models. It's based in physics. The radiative properties of the atmosphere is the basis for projections. It's as simple as, if you turn up the heat, it gets hotter. The models are only attempting to inform us about the various kinds of responses we can expect, not whether there is going to be a response or not. The models help scientists reduce the uncertainties related to the sensitivity of the climate in response to warming. The models help identify the various fingerprints of AGW.
58378. Clyde at 04:20 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       dana1981 17# If i want me house rewired i call an electrician. I can turn lights on & off too. I wouldn't try to rewire my house tho. Anybody can turn a computer on, doesn't make them a computer expert. Have a nice day all
58379. Clyde at 04:17 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Jim Eager 15# Only evidence i have is their bio's & Wiki pages. I can't say I've read every climate scientists bio & Wiki page. The ones i have read make no reference to having any expertise in the use of computers. I respectfully disagree with the models playing a small role. All future predictions/projections are based on models. If the models are wrong wouldn't the predictions/projections be wrong too?
       Moderator Response: [DB] Please relocate discussions of models to the Models are unreliable thread, where they are more properly on-topic.
58380. Dikran Marsupial at 04:11 AM on 30 May 2012
       CO2 has a short residence time
       Hi Martin, I'm sorry I haven't replied to your email yet (exam time here, only just finished my marking). I'm about to go home now, so I'll try and answer a few quick points now and will be back tomorrow. 1a. yes, the atmospheric reservoir is just the mass of carbon in the atmosphere. 1b. (Fi - Fe) is calculated via the mass balance argument (conservation of mass implies that it is the same as dC - anthropogenic emissions). So if you download the mauna loa dataset and the emissions (fossile fuels and land use change, you should be able to reproduce figure 6, which I used to calibrate the model). 2. The data for dC and anthro emissions are known with good certainty, so while Fi and Fe are uncertain, the difference between them is constrained by the uncertainty on dC and anthro emissions. I doubt the error from this source has a greater effect on the results than the crudeness of the model, which is only the simplest possible approximation. As I said in the paper it isn't of any use for quantative predictions, only for getting a qualitative understanding of the very basics. 3. or rounding somewhere. 4. I think that residence time would be for pre-industrial conditions, rather that todays, as we have increased the atmospheric reservoir above its equilibrium value (and the uptake will have increased a bit as well). The residence time (for a given isotope) is the same regardless of its origin. The important point is to explain why there is very little "anthropogenic" CO2 in the excess above the equilibrium concentration, which is because it gets replced by "natural" CO2. The residence time is really the time an individual molecule stays in the atmosphere on average, so it is really only properly defined in terms of a subset of one molecule. Sorry, have to dash now, my lift home has arrived! Hope this helps.
58381. Bob Lacatena at 04:06 AM on 30 May 2012
       CO2 limits will harm the economy
       94, D.B., I think my problem with that particular argument is that the developed world isn't bending over backwards right now to improve quality of life around the world, and the carbon footprint involved is in no way the "limiting factor." That argument amounts to "there are poor people, and if we were to actually decide to try to help them, this would make it even harder, so we shouldn't do anything." The reality is, however, that western perceptions of what will be helpful (and in fact are feasible) are simply not relevant. The simplistic idea that you'll simply change every society to live like "The West" is absurd. Real solutions involve things like this.
58382. BWTrainer at 03:59 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Howarth et al 2011 Howarth et al 2012 follow up Sorry, please feel free to delete my second comment
       Moderator Response: [Sph] Done.
58383. BWTrainer at 03:43 AM on 30 May 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       When the IEA says CO2, does it literally mean carbon dioxide, or does it mean all CO2 equivalents? I ask because the "transition away from coal power to natural gas" worries me. If research like that of Howarth et al. at Cornell bears out, the reduction in CO2 when switching from coal to nat gas is negated by the increasing methane emissions. If that's the case, then we could be in worse shape than what this report indicates.
58384. dana1981 at 03:24 AM on 30 May 2012
       Modeled and Observed Ocean Heat Content - Is There a Discrepancy?
       Pielke Sr. has a response blog post to this one. Suffice it to say Pielke Sr. is very, very confused, and he would do well to read Gavin Schmidt's explanations at RC. Note that we don't plan to respond to Pielke's post, but I thought it would be worth mentioning, since it's a direct response to this post, albeit a very confused one.
58385. dana1981 at 02:14 AM on 30 May 2012
       CO2 limits will harm the economy
       D.B. - two things. First, yes poor people can be provided with power without significantly increasing their carbon footprint, if that power is provided from renewable sources. Second, the poor are disproportionately impacted by climate change, so you have to take that factor into consideration as well when evaluating the economics of the situation.
58386. D. B. at 02:10 AM on 30 May 2012
       CO2 limits will harm the economy
       I think this article fails to adequately answer the "skeptical" viewpoint quoted at the top, since it focuses mainly on the USA. The world outside of North America contains an enormous number of very poor people who would benefit from being able to live in air-conditioned apartment buildings instead of sweltering, rat-infested slums. Can such an improvement in the masses' quality of life be achieved without increasing their carbon footprint? I suspect that the answer is no. I am not a "climate skeptic". I think that man-made climate change is real, is happening, and will probably have catastrophic effects. But a solution that involves making cheap electricity more expensive must surely be expected to place a terrible burden on the many humans who can barely afford electricity now. Arguments that carbon pricing would increase the GDP of a highly developed economy such as the United States seem irrelevant to this problem.
58387. Jim Eager at 01:46 AM on 30 May 2012
       New research from last week 21/2012
       Tom Curtis, except for two facts: 1) the Maunder Minimum of ~1645 to ~1715 was neither the end of the MWP nor the start of the LIA; and 2) natural CO2 change in response to a change in temperature is delayed by the thermal inertia of the ocean and by the ocean mixing rate, hence CO2's multi-century lag behind temperature coming out of a glaciation in the ice core record. There simply wasn't enough time for significant natural temperature-driven CO2 reduction, and certainly not in the wake of the Maunder Minimum with respect to the ca. 1600-1620 decline. See Mike Mann's RC post Global Temperatures, Volcanic Eruptions, and Trees that Didn’t Bark at http://www.realclimate.org/index.php/archives/2012/02/global-temperatures-volcanic-eruptions-and-trees-that-didnt-bark/ on his paper Underestimation of Volcanic Cooling in Tree-ring-based Reconstructions of Hemispheric Temperatures (Nature Geoscience, 2012) which cites the as yet unidentified 1258-1259 AD eruption as one a number of forcings that initiated the onset of the LIA, reinforced by other eruptions in 1452-1453, 1809 and 1815. Also see Ruddiman regarding the impact of the ~1345-1351 Black Death plague pandemic, which reduced the population of Europe by up to 60% or more in some districts, with the resulting return of considerable agricultural and grazing land to scrub and forest and consequent draw down of CO2. The point is the end of the MWP and onset and sustaining of the LIA was due to multiple factors working in concert over an extended time, including but not limited to volcanic eruptions, the Maunder Minimum, rapid and dramatic population decline in Europe and then the Americas, and a very limited response to reduced global temperature from these forcings.
       Moderator Response: TC: Link connected.
58388. Rob Honeycutt at 01:46 AM on 30 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Steve @ 34... But if you go back to the 1900's you have a much more complex question on your hands due to other forcings on the climate system. You'll note that climate scientists generally use 1970 and beyond, not because they're cherry picking, but because that is the point where anthropogenic forcing sufficiently asserts itself and becomes distinguishable over the natural system.
58389. Kevin C at 01:40 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Composer: I think that's very helpful, especially your first point. Indeed I think we could legitimately characterise the history of science as a struggle to extract nuggets of truth from the flawed, biased, and occasionally fraudulent efforts of individual scientists. In that context, the role of the social structures which have developed around the scientific endeavour become clear. The need for consensus and the gatekeeper role of journals and academic institutions is a necessary response to the fact that individual scientists are, by nature of their humanity, unreliable. It is only when you subject their work to critique before and after publication, and demand that the bulk of their opinionated and often self-important peers also be convinced, that any kind of objectivity can be obtained. If we look at the scientific endeavour in that light, then anyone making a claim on the basis of their own expertise is a fake expert (that's not exactly the original usage, but might be more useful). The only real basis for expertise is in making arguments which are grounded in a scientific consensus. That doesn't preclude new lines of research which challenge a consensus, but presenting such work to the public as fact would be inconsistent with true expertise - we could call that 'fake expertise'. Carter's piece would certainly qualify under that criteria.
58390. Composer99 at 00:40 AM on 30 May 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Geologist & Kevin C: Research in psychology increasingly shows how people tend to make decisions first, based on snap judgements, mental shortcuts, and biases, and only then use reason to rationalize their decisions after the fact. Going about things the other way around, using reason and evidence to come to a conclusion, is a difficult skill which must be carefully cultivated (especially among scientists, for whom the proper exercise of reason-based thinking is crucial). Suffice it to say, I do not think it unreasonable to expect even the best of us to operate using rational thinking all the time. Indeed I suspect most of us use instinct/irrational thinking more often than not. Given that, I think there is the wherewithal to describe Dr Carter, in the context of his activity as a climate science contrarian (including the Financial Post column which is the subject of this post), as a fake expert, without necessarily accusing him of general incompetence or of other malfeasance. All that is required is the acknowledgement that in this specific case he is not behaving with the respect for evidence & inference required in good scientific practice. ScienceBlogs' denialism blog (from which the 5 characteristics of denialism discussed elsewhere on Skeptical Science are drawn) adds context to the discussion of fake experts: Clearly, the exact definition of what an “expert” is still eludes us, but it becomes readily apparent from the legal, dictionary and common practice definitions employed by scientists what experts are not. They aren’t merely an empty set of credentials and they aren’t merely people who have at some point published in some random field. Even the rather silly expert wiki would seem to agree on this. Therefore I would say a fake expert is usually somebody who is relied upon for their credentials rather than any real experience in the field at issue, who will promote arguments that are inconsistent with the literature, aren’t generally accepted by those who study the field in question, and/or whose theories aren’t consistent with established epistemological requirements for scientific inquiry. There's no rule that fake experts can't be real experts in other contexts (e.g. Michael Egnor is a real expert neurosurgeon while a fake expert in evolutionary biology on account of espousing science denialism with regards to evolution). Bottom line: (1) Not even the best scientists are immune to irrational thinking, which is simply a function of human nature (2) Someone who is a fake expert in one field can be a real expert in others (3) Given the above, characterizing Bob Carter as playing the part of fake expert in his Financial Post letter is accurate and is not necessarily a general attack on his competence or character
58391. Steve Case at 00:09 AM on 30 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Sphaerica #30, Why do I go back to 1900 instead of choosing the 1970-2005 time frame? Because I don't believe in cherry picking. The rise in CO2 due to human activity started well before the 1970's I don't believe that the effect some how lay dormant for nearly a century.
58392. adelady at 23:58 PM on 29 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       steve, I may be wrong but I get the impression you're from the USA - in any event not from Australia. One thing that outsiders, and more than a few Australians, have trouble with is the sheer size of Australia as a whole and the gigantic expanse of desert within. Personally, I have a mental picture of Texas, probably a relic of films half-remembered from childhood, as being a dry and dusty place similar to South Australia's mid-North & Flinders Ranges region. I now know that there are 2 distinct climatic regions and probably several other smaller local climate regimes in Texas. Western Australia is a smidgen less than 4 times the size of Texas (or 150% of Alaska) but with only one southern region of good wheat growing agricultural soil that has traditionally had regular winter rainfall. In fact, Alaska might be a better comparison than multiples of Texas. Most of the interior is unsuitable for agriculture or large settlements. Only particular sub-regions have both climate and soil suitable to support agriculture. South Australia is 'only' half as big again as Texas and it lacks the tropical area that WA has in its north. We also get little to no direct benefit from increased rain in the east. Lake Eyre might be full, but that's only good for a couple of hundred locals and a few thousand seasonal tourists. The benefits to SA accruing to orchards and vineyards from increased flows into the Murray-Darling system are delayed because of its slow flows and, in any event, are of no value at all to grain growers. They need rain - from the sky, in the right quantities, at the right time for seeding, and definitely not in summer at ripening or harvest.
58393. Tom Curtis at 23:52 PM on 29 May 2012
       New research from last week 21/2012
       Dorlomin @1 and Jim Eager @3, it is probably no coincidence that CO2 levels rose circa 1000 AD, and fell circa 1620 AD. The former date coincides approximately with the start of the Medieval Warm Period, while the later, of course, coincides with the Maunder Minimum and the end of the MWP. On that basis, the probable cause of the changes in CO2 levels are simply changes in Sea Surface Temperature. On that assumption, and based on a 6.5 degree C difference in Global Mean Temperature from the LGM and Pre-industrial average with an associated 100 ppmv excursion in CO2 concentration, the CO2 record provides an approximate measure of temperature change in the MWP. The glacial benchmark sets an expected change of 15 ppmv per degree C, which means the MWP was 0.5 (WAIS divide) to 0.66 (Law Dome) warmer than the Maunder Minimum and associated LIA. Only a back of the envelope calculation, of course, but a significant reality check to those who claim the MWP was significantly warmer than the end of the 20th century, and of course, to those who claim it is the 20th century warming that has caused the modern rise in CO2 levels.
58394. Jim Eager at 23:28 PM on 29 May 2012
       New research from last week 21/2012
       Re Ahn et al (2012), as per Ruddiman, the ca. 1600 low in CO2 correlates time-wise with the ca. 1500-1600 precipitous drop in indigenous North and South American population after first contact with Europeans and unintentional exposure to their diseases, and the subsequent return of considerable agricultural land and managed forest to scrub and wild forest.
58395. Tom Curtis at 22:41 PM on 29 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Sphaerica @30, precipitation trend maps of Australia started in 1970 are potentially misleading on three counts. First, Australia's wettest three year period on record is 1974-76, due to a strong La Nina; while among its driest periods on record is the period is the early twenty-first century, where a series of El Nino's lead to extensive droughts, and in some areas a 10 year drought. Second, as you will probably have noted, Eastern Australia's rainfall is dominated by ENSO, with El Nino's bringing drought, and La Nina's floods. The intensity of that transition has increased, ie, the floods are wetter and the droughts drier, but as the long term effects of warming on ENSO are uncertain, the apparent recent trends are not projectable. Third, while anthropogenic global warming has taken of since 1975, the Earth responds to temperature change regardless of origin, and the early twentieth century saw significant warming - although not as marked in the SH as in the NH. Therefore to the extent that changes in rainfall pattern are the consequence of global warming, some of that change will have occurred between 1910 and 1940. Consequently, while the use of the 40 year trend graph was valid to show the fallacy in using Australia wide averages in testing hypotheses about regional effects, using them to predict future trends is ill advised for Eastern Australia.
58396. Bob Lacatena at 22:08 PM on 29 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Steve,

       ...the dominant change that has occurred and will probably continue to occur in a future warmer world is more rain.

       Look at the facts (particularly when the change to more rain -- beginning of the 19th century -- versus less rain -- last half of the 20th century -- occurred) and what the recent (past 40 years) trend has been, and please more accurately recast your statement concerning "and will probably continue to occur in a future warmer world."
58397. Bob Lacatena at 22:03 PM on 29 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Steve, Why do you insist on going back to 1900? Modern AGW is recognized to have taken hold starting in the late 70s. The site to which you linked actually has a map for that. Just click the "Trend" link.: So in the past 42 years, Australia looks not so good. I find it interesting that you bypassed this obvious and very relevant bit of information in your quest for knowledge.
58398. Martin A at 20:26 PM on 29 May 2012
       CO2 has a short residence time
       Dikran M: I tried to work through your paper but found I was making slow progress. So I decided to reproduce the results of your "A One-Box Model of the Carbon Cycle". Here is my working - I hope I have not made errors despite my tendency to do so. I've made my notation close to yours, though not exactly the same. If you would clarify the points I am sure of (where I've put questions), I'd be very grateful. I am eager to get to the bottom of this (residence time)/(adjustment time) question. Let: C(t) = total atmospheric carbon at time t, (Gt). Fe(t) = Rate that carbon is absorbed by the reservoir from the atmosphere at time t, (Gt yr^-1). This is taken as being given by the formula Fe(t) = ke C(t) + Fe0 where ke = 0.0135 yr^-1 and Fe0 = 182.7 Gt yr^-1 . [Please see question 1 below] Fi = rate that carbon leaves the reservoir and enters the atmosphere, assumed constant and equal to the pre-industrial emission rate, = 190.2 Gt yr^-1 (calculated from values taken from your figure 1). The differential equation for the carbon in the atmosphere is dC(t)/dt = -ke C(t) - Fe0 + Fi = -0.0135 C -182.7 + 190.2 = -0.0135 C + 7.5. [Please see question 2 below] In equilibrium, the carbon in the atmosphere is given by putting dC(t)/dt = 0, which gives Ceq = 7.5 / 0.0135 = 555.5 Gt. The solution for the differential equation, assuming C(0) = Ceq + delta is C(t) = Ceq + delta exp(-ke t). The time constant for this 1st order equation is ke, so the adjustment time is 1/ke = 74.07 yr. [Please see question 3 below] For residence time, your paper talks about carbon of natural and anthropomorphic origin. I did not see why this was necessary. As you say, nature can't distinguish the origin of CO2 molucules so I did not grasp why it is useful to calculate the lifetime of molecules of specific origin. For arbitrary CO2 molecules, the residence time in equilibrium is (content)/(throughput). So residence time = Ceq/Fi = 555.5/190.2 = 2.92 yr. General question on linearity - [Please see question 5 below] Questions 1a. Does "the size of the atmospheric reservoir" (p18) mean the mass of carbon in the atmosphere? 1b. How are the numbers for (Fi - Fe) calculated, please, (in enough detail I can calculate them myself from the Mauna Loa or other data)? 2. This involves taking differences of largish numbers which I imagine are not precisely known, to get smallish differences. An error of a few percent in the numbers would mean that their difference contained no useful information. Is there reason to believe the difference has meaning? 3. This is slightly different from your value of 74.2 yr - I assume this is a typo. 4. Have I got the residence time right (for CO2 of arbitrary origin)? Or can you help me understand why calculating the residence time of a subset of CO2 molecules is useful? 5. Linearity. In ES09, Fe was given by Fe = ke C. You have replaced this with a function Fe = f(C) where f(C) = ke C + Fe0. This function is the formula for a straight line but that does not make the equation linear, so far as I can see. For the equation dC(t)/dt = f(C) to be linear, the function f(".") must satisfy f(C1 + C2) = f(C1) + f(C2) for any C1, C2, because this is how linearity is defined. In this case, for example f(0 + 0) = f(0) = Fe0. But f(0) + f(0) = 2Fe0. So it does not, so far as I can see, qualify as a linear differential equation. Does this make sense? Have I missed something? Thank you your help.
58399. JasonB at 20:21 PM on 29 May 2012
       Dead Ahead: Less Rainfall for Drought-Sensitive Southern Hemisphere Regions?
       Steve #28, As one of a couple of million people living in that "5% of the country", allow me to point out that absolutely nothing you have said contradicts the original post in any way. As it very clearly stated, rainfall in these regions is dominated by cold fronts passing through in winter. As the temperature has risen, those fronts have move further and further south, to the extent that a significant amount of rainfall that would have made landfall in past decades now falls on the ocean to the south of the continent. The decline in rainfall and dam runoff in this region since the 1970s is well-documented and shown again by your own figures, proving the original post is correct. Before getting carried away with the importance of "averages", whether over the whole continent or even a single state like WA, you also might want to take a look at the population distribution and land usage. The north of Australia is tropical, so of course it gets a lot of rain. But most people live in the south. According to your table, WA as a whole has had an increase in rainfall of 22% -- but the south west had a decline of 17%. Guess where the people live? The largest town in the top 3/4 of that image has about 14,000 people. The state as a whole has over 2.3 million. Now look at WA in Google Maps and turn on the satellite view. Have a look at the area in WA that has recorded the biggest increase in rainfall according to the image posted by muoncounter in #14. Compare it to the area that has recorded the biggest decrease. Do you notice how the first area basically looks like desert, while the second is agricultural land? That's because the first area is basically a desert. (I grew up in that area, and in one particular two-year period the only rain we had was during cyclones.) While the rainfall might have increased, it's still not good enough (or reliable enough) to be agricultural land, whereas the area that is suffering the decrease is agricultural land -- the bread basket of the state, basically. Location matters. The problems caused by drought in one region do not disappear because there is increased rainfall in another.
58400. Jsquared at 20:09 PM on 29 May 2012
       New research from last week 21/2012
       The nicest expression for GHG production by cattle that I'm aware of is "enteric fermentation".

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