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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 51001 to 51050:

  1. The Greenhouse Gas Effect All-Star Fan Club
    Aaron, I do hope you'll go on to post your concerns with the science, and do so on the appropriate threads. For example, maybe you can help Bob Tisdale figure out a physical mechanism for his claim that ENSO is a forcing. Also, a question: what's worse -- a democracy that thinks that climate sensitivity is perhaps half of the mainstream mean, or a democracy that thinks the greenhouse effect is a fraud designed to squeeze the taxpayer? Which question deserves more attention on a site that is trying to A) communicate the published science to the general public, and B) de-bunk the accountability-free claims of the merchants of doubt?
  2. The Greenhouse Gas Effect All-Star Fan Club
    The Duncan Stewart demonstration is probably the best demonstration of the CO2 Greenhouse Effect on the web. Apparently, in some other video demonstrations, there may be other influences or contamination. Beware of smartasses who may point that out!:) Eli Rabett's Puzzle Right Results, Wrong Physics Quote: "Classroom experiments that purport to demonstrate the role of carbon dioxide’s far-infrared absorption in global climate change are more subtle than is commonly appreciated"
  3. CO2 effect is saturated
    curiousd @178, I recently created a radiative model of the atmosphere on a spreadsheet to analyze related questions. The result is that essentially all Outgoing Longwave Radiation (OLR) has its last point of emission before being radiated to space in the lower 30 km of the atmosphere, ie, from the surface, troposphere or stratosphere. Above the stratosphere, atmospheric density is so low that emissions from those altitudes are negligible. My model was too simple to include additional factors (pressure broadening of emission bands; declining CO2 content of the atmosphere above the tropopause) that would reinforce the result. Consequently any satellite, and even sufficiently high flying aircraft, will show essentially the same spectrum. You can experiment with the effect of altitude (up to 70 km) using the modtran model placed in the net by David Archer. Just compare different Iout values for different look down altitudes without changing other settings. With default settings, I obtained the following results: 70 km - 287.844 W/m^2 35 km - 287.027 W/m^2 20 km - 287.593 W/m^2 15 km - 291.863 W/m^2 10 km - 306.433 W/m^2 5 km - 348.54 W/m^2 2 km - 387.79 W/m^2
  4. The Greenhouse Gas Effect All-Star Fan Club
    Great to see a plug for Science of Doom (SoD) here. If you're keen to build your understanding of the fundamentals of this topic in a fully comprehensive and methodical way, you'll find SoD's explanations a real treat.
  5. The Greenhouse Gas Effect All-Star Fan Club
    Aaron @ 8... I believe the point is that there's a very noisy faction of climate change deniers who reject very fundamental and well understood science. If you spend any time reading the comments on WUWT, Jo Nova or Judith Curry's blogs you find that there is a sizable percentage of their most vocal following who subscribe to the "there is no greenhouse effect" theory. Those (quite honestly) insane viewpoints tend to get allowed on their blogs because they merely hold the same anti-AGW position.
  6. The Greenhouse Gas Effect All-Star Fan Club
    Aaron Edwards @8, the "ignorant small minority" represents a sizable fraction of AGW deniers on the internet including many regular readers of, and even guest commentators at AGW denial sites such as WUWT. Apart from the few rare statements such as those collected above, the opinion leaders in AGW denial largely ignore the unscientific clap trap from those who deny even the atmospheric greenhouse effect. IMO, the blind eye they turn to pseudo-scientific poppycock is motivated by their political ends. They do not debate climate science because they are interested in the truth about climate science, but because they desire a political stalemate on action to combat AGW. A political stalemate based on misinformation and pseudo-science is as useful to them as one based on valid criticisms. Indeed, in the end it is all they have to offer. Consequently they turn a blind eye the pseudo science offered by others because, politically, it is as useful as the pseudo science they themselves offer. Only when their reputation started to become tarnished by the association did they speak up - and then having made the appropriate declarations, went back to largely ignoring or egging on of the claptrap they claim is false. It is because of this lack of intellectual integrity by the leading opinion makers among AGW deniers that we must waste time rebutting nonsense such as the denial of the atmospheric greenhouse effect; or other tacit rejections of the laws of thermodynamics such as the claim that the Pacific Ocean (which is warming) has caused the atmospheric warming by loss of heat.
  7. CO2 effect is saturated
    There's a very useful description of the theory, design and operational principles of the AIRS instrumentation at JPL, curiousd. How AIRS Works I'm certainly no expert but it appears the height of the instruments in this context is insignificant in the same way the distance to a star is not important when obtaining information via spectroscopy.
  8. Sheffield vs. Dai on Drought Changes
    A good source of data, viz. drought. USA Drought Information portal.
  9. The Greenhouse Gas Effect All-Star Fan Club
    I am a newcomer to your blog and just read the article claiming that persons who are not convinced of catastrophic global warming believe that the greenhouse effect of atmospheric water vapor and other trace gases does not exist. You then list experts in the field who believe as I do (that there is no looming global warming catastrophe that will destroy mankind) who plainly state the greenhouse effect does exist. I am confused as to the point of the article. What ignorant small minority believes that there is no greenhouse effect and why do you address them? What does a reference to these inconsequential people have to do with the work of highly qualified individuals asking legitimate scientific questions about the data and the science behind the claims of the climate alarmists? I am also surprised by your statement, “Of more general interest, the history of climate science is largely the history of what we've learned about CO2.” A more accurate statement would be, “Of more general interest, the history of climate science is largely the history of what we have learned about the chaotic behavior of the ENSO and the redistribution of Pacific Ocean heat into the atmosphere.” CO2 by comparison, is inconsequential in moving heat into the atmosphere.
  10. The Greenhouse Gas Effect All-Star Fan Club
    Son of Krypton@6, *please* keep me informed of your pseudoskeptic's responses! harwig57 at gmail dot com.
  11. Son of Krypton at 02:52 AM on 5 December 2012
    The Greenhouse Gas Effect All-Star Fan Club
    @John, reading your post at work was a rather terrible idea. Trying to stifle the resulting laughs took far more effort than this cold morning warrants. This post is definitely a gem, and it will be put to good use. I've been in an online fued of sorts with a pseudoskeptic in online debates for more than a year now who often claims there is no evidence for the greenhouse effect and that CO2 is such a small trace gas that increasing amounts have negligable effects. Given that Spencer, Christy, Lindzen and Singer are his favourite sources, this should be a real treat to see
  12. 2012 SkS Weekly Digest #48
    Vrooomie: Looks like an interesting read (I just ordered it from the library). Since I'm relatively new to wrestling with the discourse and I come from a family of climate change deniers, I'm pretty sure I'm the target audience. I am still struck by the incongruity of using a mythical behavior to depict the opposing camp when the opposing camp seems to obfuscate the conversation with myth. But since I can't come up with a better image (a walrus covering it's eyes? do walruses do that?), perhaps the "useful metaphor" is appropriate.
  13. The Greenhouse Gas Effect All-Star Fan Club
    Well played, John Brookes. Well played.
  14. CO2 effect is saturated
    Question here from a physicist educator. I have looked at these satellite comparisons between time frames. I particularly like the last in the series by Chen, et al. They look at the difference between spectra taken in two different satellites between, 1970 and 2006. But, if one were to look at outgoing IR as a function of height, does not the degree of saturation and therefore the details of the spectrum depend on the height you are measuring from? Do we care how precisely these two satellites are at the same height, here? Or perhaps all satellites are so high that the effect I am concerned about is not an issue? This is my first effort to try to understand one of these satellite papers in detail. Therefore I realize my question is probably naive to the expert.
  15. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    As soon as you see "no significant warming since xxxx", you know you are dealing with the undead.
  16. The Greenhouse Gas Effect All-Star Fan Club
    I'm sorry, but just because you've got a lot of people agreeing, that doesn't make them right. I remain absolutely convinced that there is no greenhouse effect because it contravenes the 2nd law of thermodynamics. Now I don't really know what the 2nd law of thermodynamics is, but I've hung my hat on it, and there it will stay. You can't convince me I'm wrong, because I have no idea why I'm right. So don't even try, or I'll create this great big fog of words, so that no one can see what my position is at all. And more than that, I'll get indignant and abusive. So there!
  17. The Greenhouse Gas Effect All-Star Fan Club
    Definitely a keeper ;) Will use this one ;) I don't think the "skeptics" will ever give up, they will deny and deny, somewhere in 2025 we will still be discussing with some "skeptic" that there has been no statistical significant global warming since 2018
  18. The Greenhouse Gas Effect All-Star Fan Club
    Of course we hate to make predictions, but based on this emerging trend of concessions about the greenhouse effect surveyed here, I'd like to predict that the grand philosophical tradition of 'Climate Change Skepticism' will melt away at the same rate as the multi-year Arctic ice, and be all gone by the end of this decade. I can't wait to hear them denying their denial.
  19. 2012 SkS Weekly Digest #48
    AML, to fully understand the power of the term "an ostrich with its head in the sand," which is indeed a myth, but a useful metaphor, I *highly* recommend an obscure book; titled "The Standardization Of Error," By Vilhjalmur Stefansson. The term's mythic nature in no way detracts from its usefulness as a tool to describe, in simple and unambiguous terms a concept virtually all literate adults can understand. It would only be ironic is it were used as if it were employed as a fact: it is not.
  20. The Greenhouse Gas Effect All-Star Fan Club
    Amazing how the non-scientists among that august gang, can't *quite* bring themselves to unequivocally state the greenhouse effect actually exists: Monckton's "concedo" is one of the more stilted ones, reflecting his inability to just speak in plain language, ditto Jo Nova. Funny how Monckton "concedes" that the past 150+ years of research actually *might* be right! Thanks, Daniel, for a excellent, well-organized post.
  21. President Obama's Statement on Climate Change
    @vrooomie : “Had the vehicle-miles remained static”… but they don’t ! That is exactly the point I am trying to make: scientists are used to do experiments in which 1 parameter varies, while all other parameters remain fixed. It doesn’t work like that in the real world. According to the economic law of supply and demand: if the price of a product goes down (in this case the price of a vehicle-mile) then the consumption of this product increases. So consumed vehicle-miles go up as a direct consequence of improving the fuel efficiency. There is a relationship, and it must be taken into account.
  22. 2012 SkS Weekly Digest #48
    AML, in the minds of the target audience (those who do not have the time, energy, training, and or means to engage the entire body of research, but still desire to ask questions, learn, and wrestle the discourse), the myth is more likely more of a reality than the reality. In other words, it's an effective metaphor, no matter what ostriches do when they get spooked.
  23. It's El Niño
    Kevin C. Kudos for taking the time to tease apart some of the artifactual conclusions in Bob Tisdale's approach. Perhaps if he had been careful to consider and to address the fundamental questions repeatedly put to him, he might have been able to rise above his biases and see the bigger picture, and the factors that impinge on it... assuming that he does not already do so in private. I'm looking forward with interest to the validation post. Between you and Tom Curtis' patient work, perhaps Tisdale will realise that he's holding the wrong end of the stick (again, assuming that he does not already do so in private). And if he cares to refute your work and Tom's perhaps finally he'll do so with some recognition and explicit incorporation and description of the breadth of underlying physical influences.
  24. 2012 SkS Weekly Digest #48
    I just stumbled on SkS and it promises to be a great resource. Thanks for all the info! I think it's strange that the cover of the book "Climate Change Denial: Heads in the Sand" and the cartoon above both depict an ostrich with it's head in the sand. I've heard from multiple sources that this is a myth. It seems strange to appeal to the mythical effect when seeking to expose the myth promulgated by Climate Change deniers. Is it meant to be ironic?
  25. It's El Niño
    So far I’ve constructed a plausible model which the statistics say is more informative concerning the rest-of-the-world SST data. The next steps are as follows: 1. Dismantle the model to find out how it works. That’s helpful in trying to relate the model to mechanism, which is after all what we are after. 2. Validate the model: Test whether the model is robust to the choice of data and whether it has predictive power. I’ve been working on the first of these. So far I’ve highlighted how the use of two lags improves the fit to the data, as well as reducing the impact of the two anomalous features Bob identified. Whether that reduction is justified we’ll come to in the validation step. However once I started breaking down the model, it became obvious that the two-lag effect, while it makes a difference, is not the principle effect in reducing the two anomalies. The most significant causes are much simpler: The volcanic term, the trend and the scale. These are strongly interlinked in ways which are counterintuitive. Initially it seems implausible that the volcanic term should contribute to the anomalies, because they do not overlap in the time series. However, the interaction of the unmodeled volcanic term and the detrending of the SST data have exactly that effect. The reason is shown in the following animation, which shows the removal of a trend and offset from the volcanic term: Because the volcanoes are negative, detrending them shifts the whole series upwards. Because they are offset towards the start of the frame, the beginning is shifted up more. This creates a positive bias for the non-volcano influenced periods. Add a noise signal and negative excursions become ‘normal termperatures’ while positive excursions become ‘anomalies’. Now the SST signal contains the volcanic term, so detrending the SST data without removing the volcanic term introduces exactly this kind of bias. And the bias is significant in the two regions where the two anomalies occur. We would have detected this straight away had we looked at the data on a longer time frame. The interplay of all these factors in the model is moderately complex. In the following animation I’ve rolled the volcanic term into the Nino data and scaled it from zero to full scale during the animation. That takes us from the simplest Nino34-only model to a single-lag+volcano model. The model is regressed against the data with trend and offset. R2 is shown top right. The other point of note is the scale of the model. At the start the fit is very poor owing to the omission of the volcanic term from the model. The scale of the model curve is also very small - it looks too small. In fact this is the expected behaviour. The explanation is non-trivial, but is consistent with determining the ‘best’ (most probable and/or least noisy) model under the assumptions of least squares. The result can be understood from a perspective of likelihood, or least squares, or random walk statistics, but I’ve not heard a good intuitive explanation. Here are my best efforts: 1. When the model is poor, it contains features which agree and features which disagree with the data. Inflating the model increases both, but the parts that disagree quickly begin to hurt you more, so the optimum scale is smaller than the data. (From least squares.) 2. When the model is poor, you have to leave some variance for the terms that are missing from the model, and so the incomplete model must be on a smaller scale than the data. (From random walk.) This is related to the well known result that when calculating a best fit straight line through some data you get different results depending on which is the dependent variable. In other words, the scaling of the model is chosen to minimise artifacts due to the limitations of the model. It's trying to protect you from interpreting noise as signal. You can of course change the appearance of the graph by playing with the offset, scale and trend, or by adopting heuristics for setting each of these. However, there is only one ‘most probable’ model, and that is the one produced by the least squares calculation subject to the OLS assumptions. So to summarise, the two anomalies identified by Bob appear to arise from the confluence of 3 factors: 1. Bias in the trend and offset caused by the omission of the volcanic term. 2. The use of a single rather than double lag. 3. The scaling of the Nino34 data. That’s the analysis step. As I’ve said, the next step is validation. We need to test whether this model is robust - i.e. whether the results are strongly dependent on the choice of data, and whether it has predictive power.
  26. It's El Niño
    Further to my comment @146, in trying to follow up some further points I downloaded the HadSST3 data for the Nino 3.4 region, using a 15% data cutoff. I then calculated the anomaly average for 1912-1944, 1944-1976, and 1976-2006. (2006 is the last year with data available from the KNMI Climate Explorer. The calculated means are: 1912-1944: -0.068 C (compared to Tisdale's claimed 0.18 C); 1944-1976: -0.042 C (compared to Tisdale's claimed -0.05 C); and 1976-2006: 0.303 C (compared to Tisdale's claimed 1976-2011 mean of 0.16 C) Elsewhere Tisdale has claimed:
    "By smoothing NINO3.4 SST anomalies with a 121-month filter, Figure 3, the periods when El Nino and La Nina events dominated become apparent."
    While not agreeing with the supposition, the 121 month running mean of the data certainly shows Tisdale's claim that the mean of the period 1912-1944 is greater than that from 1944-1976, and even then 1976-2011 to be false: Tisdale does not specify which version of the HadSST he uses, so I obtained the graph of the HadSST2 anomaly data for the Nino 3.4 region to ensure the problem was not just the updated data set: You can easily detect the periods of interest. 1912 immediately follows the very large negative excursion just after 1900 (the largest La Nina event on record according to the SOI). 1944 immediately follows the large positive excursion following 1940. 1976 immediately follows the double troughed negative excursion preceding 1980. The data from 1912-1944 is a little noisy, even though I used the 0% cutoff on data to net every observation in the region. Never-the-less it is clear that the peaks (El Ninos) in 1912-1944 are not as strong as those from 1976 forward; and that the troughs (La Ninas) are both deeper and more frequent. Therefore the difference between my and Tisdale's result is not a consequence of the different data sets. It looks to me as though Tisdale has subtracted a linear trend from the anomaly. However, he does not mention doing so. Bob, would you please specify the exact methods used in obtaining your averages? And would you also specify the exact cutoff dates for your periods of interest?
  27. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    DSL, Doug, Ian and Stephen, Thanks for your help - I now understand where I went (very) wrong. SKL's point about the glossary is a good one - the acronyms in climate science are a minefield unless you are an aficionado!
    Moderator Response: [DB] A Glossary is under development.
  28. Stephen Baines at 03:58 AM on 4 December 2012
    Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    Sorry...I meant the prediction based on equilibrium climate sensitivity should be substantially higher than observed over a short time frame, before equilibrium occurs.
  29. Stephen Baines at 03:50 AM on 4 December 2012
    Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    Jim, As usual other respond before I do. First, the relative increase in CO2 emissions that you cite is not equal to the relative increase in atmospheric CO2 concentrations. Think of it this way. If one triples the rate of water coming into a pool, the volume of water in the pool does not instantly increase three-fold in volume. The response depends on how much water is already in the pool. Second, according to the earth system research laboratory, atmospheric CO2 concentration increased by only about 5.3% over the decade between 2000 and 2010, from 367 ppm to 388.5 ppm. Given a climate sensitivity of 3C/doubling that equates to a 0.16 C (0.1-0.24 C range)increase in equilibrium temperature. That's pretty darn close to you 0.15C! Finally, the climate sensitivity refers to equilibrium global temperatures. The climate system will not have reached equilibrium over only 10 years -- it takes a number of decades for the oceans, land and atmosphere to heat up enough that radiation leaving earth for space matches the radiation absorbed by the planet. So we would expect the temperature prediction based on the equilibrium climate sensitivity to be a bit lower than the observed value. So the good match actually suggests the IPCC could be underestimating sensitivity rather than overestimating it. I doubt you could make much hay of that though. You're dealing with a short rather arbitrary time frame, wide range climate sensitivities and the residual natural variability that was not removed by Foster and Rahmstorf's approach. Also, there was probably delayed warming in the pipeline from previous increases in CO2.
  30. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    Hi Jim, The 2.0-4.5 degrees range given by the IPCC is the equilibrium change expected from a doubling of CO2, which is equivalent to 280 parts per million (ppm) in concentration. Based on data at Mauna Loa, the concentration of CO2 has increased from about 370 to 390 ppm over the past decade, which is about only 7% of 280ppm. I suspect that the figure you've seen refers to the rate of CO2 emission increasing by a third, but not the CO2 concentration increasing by a third. In addition, the 2.0-4.5 degrees refers to the warming expected at equilibrium, and in reality it takes a while for the atmosphere and oceans to warm up. When atmospheric CO2 hits 560ppm, the warming observed at that point will in fact be a bit lower than 2.0-4.5 degrees, as it takes a few decades for the earth to catch up.
  31. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    Jim, if I'm understanding your question correctly that's a common point of confusion and has to do with the difference between short term and long term responses of climate to changes in GHG. IPCC is referring to "equilibrium climate sensitivity" or ECS, the expected result once the ocean-air system has stabilized around a new distribution of GHG. The ocean will absorb an enormous amount of heat before equilibrium temperature is attained, during a period dominated by "transient climate response" or TCR, the phase we're in now. Picture cooking a turkey from a refrigerated state in an oven that is well-insulated but with a small heating element. The air temperature in the oven will remain relatively low as the turkey warms. The turkey-air combination will reach equilibrium temperature after the turkey is completely warmed to the point where heat leaking from the oven prevents further increase of the oven chamber temperature.
  32. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    Hi jim. I suspect someone is going to answer you in much greater detail, but I'll try now. There is a difference between equilibrium climate response (ECR) and transient climate response (TCR). Much of the response from a given increase in CO2 comes through feedbacks to the initial warming. Those feedbacks are not immediately realized. Further, the oceans represent 92-3% of the thermal capacity of the climate system. They do not release stored energy immediately. Indeed, they may store energy for centuries. ECR is the final realization, in surface temp (if that's the metric you choose), of a given increase in CO2. TCR is what's happening right now. The IPCC uses ECR much more often than TCR, though I wonder if TCR will get further discussion in AR5, since it's one of the less well-understood concepts. SkS needs a glossary, people! (Don't look at me. I have grading to do!)
  33. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    I am a septuagenarian layman interested in understanding the science behind global warming even though it won't effect me. I find it difficult to reconcile fig.2 with the statement that it confirms IPCC projections. It shows a temperature rise of about 0.15 degrees over the decade to 2010. It is reported elsewhere that the annual tonnage of global carbon emissions increased by a third over the same period. IPCC report AR4 (WG1 chapter eleven, final par.) gives a range of 2.0 to 4.5 degrees for the projected temperature increase likely to be caused by a doubling of atmospheric CO2. If we divide by three to get a range for an increase in atmospheric CO2 of one third, we get 0.66 to 1.5 degrees - appreciably greater than 0.15 degrees. I realise that my approach is extremely simplistic, but the difference is so great that someone better qualified to comment than myself might care to do so.
  34. It's El Niño
    Bob Tisdale
    KR asks: “Finally, what about the greenhouse effect?” [more than sufficient to cause observed warming without asymmetric ENSO] Downward longwave radiation appears to do nothing more cause a little more evaporation from the ocean surface, which makes perfect sense since it only penetrates the top few millimeters.
    I'm afraid this rather glib dismissal of the greenhouse effect fails to substitute for science. Despite the short penetration depth of longwave radiation, it is more than sufficient to greatly warm the oceans by changing the skin layer temperature gradient, the top millimeter of the oceans. There's an excellent article on it here, including the experimental evidence - one of the better discussions I've seen on the topic, in fact. Again - the radiative greenhouse effect more than accounts for the observed warming of the last 50 years. Forcings during the early 20th century (in particular high insolation and quite low volcanic aerosols) account for early 20th century warming, too, despite your statements. Claims of asymmetric ENSO forcings (in addition to lacking a physical mechanism for asymmetry) simply have no support from the full temperature record. To be blunt, I consider both your (a) assertion of (recently) asymmetric ENSO's and (b) dismissal of the accumulated evidence for the radiative greenhouse effect to be equally glib handwaving. You've failed to support either with clear, testable hypotheses, or to even discuss the (multiple) lines of evidence contradicting your hypotheses.
  35. Climate's changed before
    Dan, depending on one's understanding of utilitarianism, one can argue either that ag civilization is more horrible because it brings misery to more individuals (in sheer numbers), or one can argue that the preceding h-g cultures caused more misery because lifespans were shorter, survival was much more in doubt for a given individual, and individual freedom was extremely limited. I disagree that ag society brought wars of territory and economy. I argue that climate stability brought those features. A long, warm, stable climate allowed territorial expansion and population growth. Eventually, h-g groups would have started to bump into each other, as they undoubtedly did during the glacial periods. Ag culture simply speeded up the process. Ag culture also allows the development of science, which gives us the chance--the chance--to become responsible about what happens next. dan: "start a fire in your backyard and reconnect with the primitive beast." Ok, but later on in the evening I'll come back to the internet. The more we disconnect with each other, the more willing we are to cause others pain and misery. If science and then engineering can force us to look into each others' eyes while we have our fingers on triggers (literal or metaphorical), then I'm all for it. If seven billion people go primitive right now, six billion die within two years.
  36. 2012: Record Arctic Sea Ice Melt, Multiple Extremes and High Temperatures
    The HadCRUT temperature anomaly map makes it clear why it's the favourite temperature series for pseudoskeptics. Look at all those gaps in coverage at the poles.
  37. It's El Niño
    Actually, I think I've misrepresented the cause of the artifacts in Bob's figure 13. I only get odd minutes to work on this, so I've only just got to the point of picking my model apart again to see what is happening inside. It now looks like the cause of Bob's artifacts is even simpler than I have suggested. The multiple lags thing is real and very interesting scientifically, but it's not the dominant factor in the features of figure 13. I'll try and give a fuller analysis over the next few days. Then move on to strict validation tests to confirm or refute my hypothesis next weekend.
  38. Newcomers, Start Here
    I have gained so much from this site I wish to donate. But I find Paypal difficult to use in my case. Any way I can use a regular credit card, send a check, anything?
  39. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    It is pretty describing that out of the 17 denialists mentioned in the article, no less than three of them (Giæver, Humlum, Solheim) all come from a tiny, semi Arctic country with a population of not much more than 4 million. These disinformers get quoted frequently in the national press, while those top level climate scientists who produce real science (Benestad, Drange, etc) rarely get any mention and have their replies to the frequent denialist Op-eds censored, etc. 2012 was a game changer in the US, and it looks like the population finally woke up, thus the increased desperation of the denial industry. For Europe, and especially Northern Europe, the opposite is the case. A cold and wet summer has now been replaced by frigid winter conditions, due to the negative NAO. As a result, denialism is thriving.
  40. Climate's changed before
    Ah dan, such romantic notions... Back to reality. Physics says that the moon's effects are insufficient to drive large geophysical events, though you're right that we should be grateful to the Moon for stabilising Earth's axial tilt. But crackpots like Ken Ring prey on the superstitious and gullible to garner a little fame for themselves. Don't fall for the astrologers! Real-world geophysical events are not controlled by the Moon, but by much larger forces - motions, stresses and sources of heat within the Earth. And don't be afraid when the Moon is a wee bit bigger in the sky due to entirely normal and predictable occurrences of lunar perigee. One happened on 14th November during the total eclipse - it was the reason the Moon was big enough to cover the Sun for a beautiful, utterly predictable event. Another will happen in about nine days time, when the moon will be an unspectacular waning crescent in the dawn sky. In fact, 12 have come and gone this year! About once a year, the media gets all excited because perigee roughly coincides with a Full Moon, leading to the so-called "supermoon" (really, nothing special, though some decent spring tides). Do yourself a favour, dan, and ignore the astrologers like New Zealands woeful Moon Man.
  41. It's El Niño
    Bob Tisdale #140: You did not answer my questions. That's why I asked them. And your video does not answer them either. I'll echo Sphaerica's request for nice clear answers that would fill the crucial, enormous holes in your vague conjectures. Without them your conjectures are, to me, utterly worthless.
    [From Tisdale's #139:] Composer99 replied, “No, they can't. Ocean heat has to come from somewhere.” [Tisdale responded:] Apparently you have never divided OHC data into subsets, because if you had, you would not make such a statement. Dividing the oceans into subsets shows the ocean heat comes from somewhere, but it’s not CO2.
    That's a truly staggeringly nonsensical statement. Apparently you think that you can increase the quantity of something by dividing it up, that's an interesting recipe for a perpetual motion machine. Try it with an orange sometime? sigh, where's the heat coming from, Bob, and why only within the last century or so? You are presently magicking an enormous amount of energy into existence with an alacrity that would truly alarm Einstein and Hawking...
  42. Climate's changed before
    human agricultural civilisation was the worst development in our history and the beginning of the splintering of our psyches, the start of war and teritorialism, in turn monarchies, and the large scale oppression of human subjects. Hunter gatherers live in complete harmony with their environment, taking only what they need. Not like modern capitalsitic practice of over supply of mcdonalds beef burgers.whats more, recreation time lead to crackpot theories of gods and the like and more recently the splintered sciences hypotheses. what are they all observing their own little fragmented view of inconsequentiality. Its like in my city, christchurch which had an earthquake. the scientists can only study the after effects, and they get funding for doing that? unbelievable. whereas we had a moon man who studies the cycles of the supermoons and he actually predicted a big one was coming, the scientific community was upset about it but why can't the moon effect things. last time i heard its the only reason earth is inhabitable due to axis for seasons to be temperate. people cant see the wood for the trees. theyre observing things but understanding little. media is a sensationalist scaremongering thoughtless behemouth.start a fire in your backyard and reconnect with the primitive beast.
  43. 2012 SkS Bi-Weekly News Roundup #6
    I've noticed the popular env news are getting increasingly pessimistic lately. For example my local smh: It's the end of the world as we know it 4 to 6 degree C is really on the verge of "alarmist" (the negative meaning of this word) & would've been considered unjustified short time ago. I think the impending talks in Doha and the morbid reality that the preceding conferences made no difference to the increasing emissions, rendered some people increasingly fatalistic.
  44. Rahmstorf et al. Validate IPCC Temperature Projections, Find Sea Level Rise Underestimated
    GIF suggestion... I would love to see something like this, that animates the concept for each of the IPCC reports. Of course, finding published data to base it on is probably not going to happen, so maybe its out of your bailiwick. Still.... it would be a great tool for combatting the notion that the science only moves every 7 years. http://thinkprogress.org/climate/2012/12/02/1253931/ipccs-planned-obsolescence-fifth-assessment-report-will-ignore-crucial-permafrost-carbon-feedback/#comment-595051
  45. It's El Niño
    Bob, Your claim here that Gavin Schmidt at Realclimate says you can compare a single realization (what happened) to the model average and not to the model envelope is simply untrue. The single realization includes all the noise. Your conclusion that temperatures are not what was predicted relies on this noise alone. It is clear that you are not on a reality based program. I do not have time to exchange comments with such clap trap. I am withdrawing from the exchange.
  46. The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
    In the Wikipedia article, Clyde@14 has linked to, Trenberth is quoted:
    "The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be."
    And he goes on to explain the differences between weather and climate. The fact that after having read it (supposedly), Clyde continues to ask a question of "proof what Sandy would have been if..." indicates that Clyde did not understand own link! We all know the basic difference between weather and climate predictions: weather is about extrapolating the current precise conditions into the short future, climate is about modelling the average long-term conditions. Clyde's question does not make sense because it confuses/contradicts weather terms with climate terms (especially this silly "proof, what if" requisition made me laugh big times!), while Kevin's question is a very reasonable question about an average fingerprint of a changing climate.
  47. Subcap Methane Feedbacks, Part 1: Fossil methane seepage in Alaska
    Catman, I fear that the emissions from the planes would do more harm than any good the snow might do. Better just to put sulphur in jet fuel and make the stratosphere more reflective. Not that I'm advocating that either. We have to give an emissions diet a good go before we try the climate equivalent of gastric bypass or liposuction.
  48. SkS at the AGU 2012 Fall Meeting
    It's excellent that somebody (Andy!) has done a more formal connection between London's former lethal problem with missing sewers and our problem with CO2. It's such a fine parallel; excrement is found in nature, is plant food, etc. but we don't pretend we can dump it willy-nilly without facing consequences. Our present CO2 effluent has been fairly easy to ignore because until recently we've assumed our sewer pipe entirely empties into the future. When we think it's not us who're being covered in our crap but our descendants we really don't give a s__t, so to speak. Along those lines, as the length of our "cloaca maxima" into the future appears to be shrinking our interest in repairing the problem is becoming more urgent.
  49. Subcap Methane Feedbacks, Part 1: Fossil methane seepage in Alaska
    Here’s some geo-engineering that we might be able to all agree on: Fly tankers and fire planes over areas of the permafrost where the surface temperature is below freezing but there is no snow. Equip the planes with snow making equipment. Even a very light dusting of snow will increase the albedo and prevent any further melting by solar radiation. Satellite observations can instruct the pilots where to fly. We have to DO something, don’t we?
  50. It's El Niño
    Bob Tisdale @134 claims that:
    "El Niño events were also dominant during the early warming period of the 20th Century, and global temperatures warmed in response then, too."
    That is a breath taking claim, but he appears to support it with a graph showing the average SST anomaly in the ENSO 3.4 region in the period 1912-1944 was 0.02 C warmer than that in the period from 1976 to 2011. He neglects to mention that the later half (1999-2011) of the second period is La Nina dominated, significantly bringing down its average temperature. Using the Reynold's data from Nov 1981 to the end of 1998, the average anomaly is 0.22 degrees C, whereas that from November 1981-Dec 2011 is only 0.08 C, the difference being because of because the average anomaly from Jan 1999 to Dec 2011 is -0.11 C. This raises two questions. Why did Tisdale include a La Nina dominated period in his final period, when he must know that doing so will distort the comparison with the earlier period? And if La Nina dominated periods cause cooling, why has there been no cooling in the La Nina dominated period from Jan 1999 to the present? Tisdale's response cannot be that El Nino dominated periods cause warming, but La Nina dominated periods do not cause cooling, for as he says, the El Nino Southern Oscillation has been in existence for millions of years. If it acts to warm in El Nino dominated periods, but does not equally act to cool in La Nina dominated periods, it must act as a ratchet on global temperatures, pushing them always higher, which of course, has not occurred over those millions of years. That, however, is not the issue I wish to pursue in this post. Interestingly, in his comment @137 Tisdale quotes Compo and Sardeshmuk (2010) as saying:
    "In particular, defining ENSO in terms of a single index and ENSO-related variations in terms of regressions on that index, as done in many previous studies, can lead to wrong conclusions. This paper argues that ENSO is best viewed not as a number but as an evolving dynamical process for this purpose."
    Tisdale emphasized that point, which is odd given that he persistently uses just one, temperature based index of ENSO activity. While he wants to drive the point home, he appears also to want to ignore its implications regarding his methods. Indeed, Compo and Sardeshmuk expanded further on this theme:
    "One immediate difficulty with using such single-index definitions of ENSO is that no ENSO-unrelated variations can occur in that index. If one uses the Nino-3.4 SST index, for example, then no ENSO-unrelated 'global warming' signal can ever occur in the Nino-3.4 region - by definition."
    (Original emphasis) It should not need saying that other sources of SST fluctuation are also excluded by definition. Therefore simply taking the SST anomaly in the Nino 3.4 region over vastly different time periods cannot plausibly be considered a measure of ENSO activity. It in no way allows for the effects of other factors which we know will cause changes in the SST in the Nino 3.4 region as much as anywhere else. As I have previously indicated, I dislike the Nino 3.4 index for exactly this reason. While suitable for short term comparisons, it is not suitable for comparisons across the span of a century. A far more suitable measure in the Southern Oscillation Index (SOI): Even a brief glance shows that the period 1912-1944 is nowhere near as dominated by El Nino Events as that between 1976-1998. The cumulative sum of the inverted SOI for the former period is negative 10.34, while that of the latter is positive 87.23. Even including the full 1976-2011 interval results in a cumulative sum of 56.01, despite the very negative 32.21 cumulative sum for 1999-2011. So, contrary to Tisdale, the period of rapid temperature increase in the early Twentieth century was ENSO neutral, and leaning towards La Nina dominance rather than the reverse.

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