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Comments 51151 to 51200:

51151. AML at 11:16 AM on 4 December 2012
       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?
51152. Kevin C at 07:33 AM on 4 December 2012
       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.
51153. Tom Curtis at 06:25 AM on 4 December 2012
       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?
51154. jim7917 at 04:25 AM on 4 December 2012
       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.
51155. 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.
51156. 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.
51157. IanC at 03:39 AM on 4 December 2012
       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.
51158. Doug Bostrom at 03:33 AM on 4 December 2012
       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.
51159. DSL at 03:28 AM on 4 December 2012
       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!)
51160. jim7917 at 02:35 AM on 4 December 2012
       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.
51161. KR at 01:49 AM on 4 December 2012
       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.
51162. DSL at 00:30 AM on 4 December 2012
       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.
51163. Composer99 at 23:53 PM on 3 December 2012
       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.
51164. Kevin C at 22:50 PM on 3 December 2012
       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.
51165. curiousd at 20:53 PM on 3 December 2012
       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?
51166. Esop at 20:30 PM on 3 December 2012
       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.
51167. skywatcher at 19:43 PM on 3 December 2012
       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.
51168. skywatcher at 19:20 PM on 3 December 2012
       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...
51169. dan7912 at 18:04 PM on 3 December 2012
       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.
51170. chriskoz at 13:36 PM on 3 December 2012
       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.
51171. Mark-US at 13:22 PM on 3 December 2012
       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
51172. michael sweet at 12:58 PM on 3 December 2012
       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.
51173. chriskoz at 12:57 PM on 3 December 2012
       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.
51174. Andy Skuce at 11:49 AM on 3 December 2012
       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.
51175. Doug Bostrom at 10:46 AM on 3 December 2012
       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.
51176. catman306 at 09:47 AM on 3 December 2012
       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?
51177. Tom Curtis at 09:39 AM on 3 December 2012
       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.
51178. Bernard J. at 08:26 AM on 3 December 2012
       It's El Niño
       Like Doug I have no desire to pile on to Tisdale, although his persistent skirting of the hanging questions makes it difficult not to do so when entering the fray. However, he made a comment at #134 that I'd like to have clarified:

       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.

       Specifically, I would like to know by exactly how much Tisdale believes that "[d]ownward longwave radiation" does or does not contribute to warming of the planet in terms of a particular DLR flux, and by what mechanisms that warming does - or indeed does not - does not occur. Numbers and primary references would assist to make an objective and nuanced case.
51179. Kevin C at 07:43 AM on 3 December 2012
       The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
       Clyde: Can anybody proof what Sandy would have been if GW was smaller? I presume you are aware of the rhetorical device of deliberately asking an unanswerable question (for example by comparison to a hypothetical), and then drawing a conclusion from the fact that the question is unanswered? Let me respond with a very concrete and answerable question: According to Munich Re by what factor have weather and climate related disaster losses increased compared to earthquake losses when comparing the period since 2000 to the period before 1980?
51180. Kevin C at 07:31 AM on 3 December 2012
       It's El Niño
       Bob: You are claiming that the difference between Nino34 and the rest of the world temperature is real. Well, yes, I don’t dispute that. However, in attaching meaning to that difference, you are implicitly assuming a model. Just because your model is very simple, doesn’t mean it isn’t there. And you conclusions are totally dependent on the validity of that model. You implicit model seems to be something like this: Ignoring volcanoes, the rest of the world temperatures track Nino34 with a single lag, except for some significant deviations which require another explanation. There’s a huge assumption here. (In fact there are several, but one is relevant.) You have assumed that normally the whole of the rest of the world SST follow Nino34 with a single lag. Using your knowledge of teleconnections, do you consider that to be a safe assumption? Now, you may have been led to make this assumption because others have made it before, notably Foster and Rahmstorf. That doesn’t make it true. It needs to be checked to see if it affects the conclusions for a particular question. I’ll be looking into that for F&R in the light of what we’ve done here, but that’s not the subject at hand. So let’s do the check for your problem. This is a much simpler calculation. Let us create a hypothetical system in which two lags are presents, so that the mean SST over the rest of the globe is the sum of two equal Nino34 terms with lags of 9 and 46 weeks. Now suppose we try to fit the SST with just a single lag. Here’s what the true SST and best single lag model look like: Note that the model has some serious deviations, especially around 1998-2001, but also 1985 and 1989. These deviations are solely due to the failure of the model to reflect the known behaviour of our hypothetical system. I presume you will therefore accept that if we were to attempt to draw conclusions from these divergences, those conclusions would be fantasy? If so, then the question we have to ask is how does the real system behaves. In order to justify your conclusions, you need to establish that your single lag model is realistic. I made no such assumption - rather I asked the data what lags were present, using very conservative statistical tests to avoid overfitting. There are a number of other tests of various kinds we can apply to see whose is the better model - I suspect we will be working through them over the next few weeks. However the whole discussion is missing the really interesting bit of the science. The 2-lag (and possibly 3-lag) solution is potentially interesting from the point of view of ENSO and teleconnections. We’ve got the first piece in the puzzle and there are obvious ways to explore this further on a spatial as well as temporal level. It’s your project, there may be a paper in it, and I really don’t want to do it for you - I’ve got more unwritten papers than I can handle already.
51181. scaddenp at 06:25 AM on 3 December 2012
       Subcap Methane Feedbacks, Part 1: Fossil methane seepage in Alaska
       The link doesnt take me to that article, but 1500% increase on a very small no. is still a small no. Thin film can mean CdTe with the toxicity problems but can also mean CIGS or psDye technologies. You seem to be claiming nitroflouride is used for other types of PV for which I can find no support at all. It is not used for purification, only for etching. The "big" increase in atmospheric levels (to 0.5 parts per trillion) is more to do with liquid crystal displays than thin film PV. You dont need to spend carbon to make them either. I would also agree that for industrial scale, CSP is better solar option than PV. While I do agree that nothing is cheaper than conservation, making substantial savings in a democracy is difficult to do. I highly recommend Sustainable energy without Hot Air for that kind of study.
51182. IanC at 05:16 AM on 3 December 2012
       It's El Niño
       Bob, So in short, you are very certain that you are correct, and see no possible reason for your analysis to be flawed? By the way, I'm mainly referring to PDO and decadal temperature trends.
51183. Doug Bostrom at 04:45 AM on 3 December 2012
       It's El Niño
       I'd rather not add another question to the heap here but if we're to accept the description Bob provides us we need to ask how the reversal of entropy works in his system. In order for Bob's scenario to work there needs to be some kind of heat pump added to the picture. Bob, where's the heat pump? How does it function?
51184. sidd at 03:56 AM on 3 December 2012
       2012 SkS Bi-Weekly News Roundup #6
       Denial is misspelt in the title. No need to post this, but please correct.
       Moderator Response: [d_b] Fixed. Thank you.
51185. Andreas at 02:43 AM on 3 December 2012
       The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
       The Financial Post article also contains a claim that "The NOAA “State of the Climate in 2008” report asserted that 15 years or more without any statistically-significant warming would indicate a discrepancy between observation and prediction. Sixteen years without warming have therefore now proven that the models are wrong by their creators’ own criterion." This doesn't seem like a correct reading of the NOAA report. The claim from NOAA seems to be that an _observed_ 16-year trend of zero (or negative) warming would deviate statistically from the model. The FP article claims instead that any trend non-significantly different from zero (no matter how positive) invalidates the model. That is something quite different, and in the denialist's favour. (the NOAA report is linked from the FP article. See p23-24 in the report.)
51186. John Hartz at 01:46 AM on 3 December 2012
       It's El Niño
       @Bob Tisdale: You have not responded to the question I posed to you in #121. For everyone's convenience, I will repost it here. Do you believe the following graph to be a valid representation of Jan-Oct global land & and surface temperature anomalies with respect to the 1961-1990 base period for calendar years 1950 through 2012? Source: 2012: Record Arctic Sea Ice Melt, Multiple Extremes and High Temperatures, WMO Press Release No 966, Nov 28, 2012
51187. DSL at 01:22 AM on 3 December 2012
       Climate's changed before
       Dan, you're right: if we de-funded the education system, life would be simpler. We'd all believe whatever our priests told us, we'd have much shorter lifespans, and most of us would be in the ag industry (and not as property owners). We would not be swilling down Nut Browne Ale in a Public House in Merry Olde Englande. Actually, we'd probably all be dead. If AIDS had developed in 1400 instead of the 1970s, it would have been much worse. And children? What was the global child mortality rate in 1700? What's the point of all the scare-mongering? Think of the children. You clearly are not. In Europe, the Little Ice Age represented a .5C-.8C drop in temp (from the Medieval Climate Anomaly). It was not pleasant for the children of Europe. Rapid climate change is never pleasant for children, because it usually puts a strain on food supply. Why, you might wonder, did humans evolve agricultural civilization over the past 10k years instead of some other 10k year period? It's not like we haven't been smart enough. Indeed, a recent study concluded that we've become worse at problem solving over the last 10k years. So what was it? Try climate stability. The Holocene has been remarkably stable, as interglacials go. Human cultural memory, in fact, assumes a stable climate. There are no representations of persistent instability of the type that occurred during glacial periods and previous interglacials. We assume a stable climate. We have trouble imagining anything else. Even when we imagine it--with the help of science even--it's still so unreal that we can't imagine the full range of everyday consequences. Writers have tried. We're going to get persistent instability for quite a while, dan. If we de-fund education, then we de-fund the means of thinking through the persistent change. You perhaps imagine a world where we drop back and rely on conventional wisdom with regards to the weather and agriculture. No. Weather is changing, and it is not changing from one regime to another. It is persistent change. All systems are changing: climate is everywhere. If you de-fund education, you blind the world just as it is walking across a period that, metaphorically, is the top surface of a glacier. Of course, we may be blind already, since the "brains" of the world, the political guidance, do not believe their "eyes." Oh, and dan, imagine living your life according to the comet theory: at any point, a stray bullet could come through the window and kill you. Why do anything? Why post your comment?
51188. Bob Tisdale at 01:06 AM on 3 December 2012
       It's El Niño
       Skywatcher says at 138: “To date I have not seen you directly tackle these absolutely crucial questions, despite several of them being asked on this thread.” I believe I’ve answered your questions. Please review my comments on this thread, including the ones I posted while you were writing yours. As opposed to my answering your questions by cutting and pasting those comments, here’s a link to a video that also answers all of your questions: https://www.youtube.com/watch?v=lmjaNO5DD_Q
       Moderator Response: [Sph] I'm sorry, but no, they have not been answered, and they are simple, straightforward questions that deserve simple, straightforward and clear answers.
       
       I think Skywatcher's request deserves a non-evasive response (a link to an hour long video is hardly a response to a question).
       
       I would suggest, for clarity, posting one comment for each question, and sticking to the question being addressed, to avoid any confusion. Please answer the questions directly and succinctly.
51189. Bob Tisdale at 00:49 AM on 3 December 2012
       It's El Niño
       

       At comment 107, Composer99 quoted one of my earlier comments: “Are you aware that the global oceans can be divided into logical subsets which show the ocean heat content warmed naturally?”

       Composer99 replied, “No, they can't. Ocean heat has to come from somewhere.”

       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.

       For the sake of discussion, I’m going to borrow some graphs from an upcoming post. Here’s a comparison graph of Global ocean heat content and the ocean heat content for the Pacific Ocean north of 24S, which captures the tropical Pacific and the extratropics of the North Pacific (24S-65N, 120E-80W). The Pacific OHC (North of 24S) shows similar but somewhat noisier warming. That is, the decadal variations are similar. The warm trend of the Pacific subset is about 72% of the global trend, but that’s to be expected since the excessive warming of the North Atlantic OHC skews the global data. All in all, both datasets give the impression of a long-term warming that’s somewhat continuous. People might assume the warmings of both datasets were caused by CO2.

       We’re going to separate the tropical Pacific (24S-24N) from the extratropical North Pacific (25N-65N), looking at the tropical Pacific first, but that requires a brief overview of how La Niña events produce the warm water that fuel El Niño events.

       El Niño and La Niña events are part of a coupled ocean-atmosphere process. Sea surface temperatures, trade winds, cloud cover, downward shortwave radiation (aka visible sunlight), ocean heat content, and subsurface ocean processes (upwelling, subsurface currents, thermocline depth, downwelling and upwelling Kelvin waves, etc.) all interact. They’re dependent on one another. During a La Nina, trade winds are stronger than normal. The stronger trade winds reduce cloud cover, which, in turn, allows more downward shortwave radiation to enter and warm the tropical Pacific.

       If you’re having trouble with my explanation because it’s so simple, refer to Pavlakis et al (2008) paper “ENSO Surface Shortwave Radiation Forcing over the Tropical Pacific.” Note the inverse relationship between downward shortwave radiation and the sea surface temperature anomalies of the NINO3.4 region in their Figure 6. During El Niño events, warm water from the surface and below the surface of the West Pacific Warm Pool slosh east, so the sea surface temperatures of the NINO3.4 region warm, causing more evaporation and more clouds, which reduce downward shortwave radiation. During La Niña events, stronger trade winds cause more upwelling of cool water from below the surface of the eastern equatorial Pacific, so sea surface temperature to drop in the NINO3.4 region, in turn causing less evaporation. The stronger trade winds also push cloud cover farther to the west than normal. As a result of the reduced cloud cover, more downward shortwave radiation is allowed to enter and warm the tropical Pacific during La Niña events.

       To complement that, here’s a graph to show the interrelationship between the sea surface temperature anomalies of the NINO3.4 region and cloud cover for the regions presented by Pavlakis et al.

       That discussion explains why the long-term warming of the Ocean Heat Content for the tropical Pacific was caused by the 3-year La Nina events and the unusual 1995/96 La Niña. First, here’s a graph of tropical Pacific Ocean Heat Content. It’s color coded to isolate the data between and after the 3-year La Niña events of 1954-57, 1973-76 and 1998-2001. Those La Niña events are shown in red. Note how the ocean heat content there cools between the 3-year La Niña events. Anyone who understands ENSO would easily comprehend how and why that happens. It’s tough to claim that greenhouse gases have caused the warming of the tropical Pacific when the tropical Pacific cools for multidecadal periods between the 3-year La Niñas, Composer99.

       As you can see, the warming that took place during the 1995/96 La Niña was freakish. Refer to McPhaden 1999 “Genesis and Evolution of the 1997-98 El Niño”.

       McPhaden writes:

       For at least a year before the onset of the 1997–98 El Niño, there was a buildup of heat content in the western equatorial Pacific due to stronger than normal trade winds associated with a weak La Niña in 1995–96.

       Based on the earlier description, that “build up of heat content” resulted from the interdependence of trade winds, cloud cover, downward shortwave radiation and ocean heat content. Simple. As you can see in the above graph, the upward spike caused by the 1995/96 La Niña skews the trend of the mid-cooling period, and if we eliminate the data associated with it and the 1997/98 El Niño, then the trend line for the mid-period falls into line with the others.

       So far, there’s no apparent AGW signal.

       Let’s move on to the extratropical North Pacific. That dataset cooled significantly from 1955 to 1988, more than 3 decades. Where’s the CO2 warming signal there, Composer99? Then in 1989 and 1990, there was an upward shift. It’s really tough to miss, because the North Pacific was cooling before the sudden 2-year warming and then it warmed after it. As you’ll note, the cooling trend before the shift is comparable to the warming trend after it. BUT, big but, the cooling period lasted for 34 years, while the warming period only lasted for 22 years. That means the North Pacific (north of 24N) would have cooled since 1955 if it wasn’t for that 2-year upward shift.

       In summary, the ocean heat content data for the Pacific Ocean north of 24s (the initial graph)  gives misleading impression of a relatively continuous warming; it’s misleading because, when the data is broken down into two logical subsets, tropics versus extratropics of the North Pacific, the data clearly shows that factors other than greenhouse gases were responsible for the warming.

51190. skywatcher at 00:42 AM on 3 December 2012
       It's El Niño
       Bob, in all your focus on one region of the Earth, you have apparently neatly dodged important questions with relation to global warming and your unusual conjectures: 1: Where's the heat coming from? The oceans, globally, are warming, the atmosphere is warming, and yet the Sun is not getting any brighter. What's your energy source? 2: What's the physical mechanism involved, if it's not the rise in greenhouse gases? Sloshing water about the oceans does not appear adequate if the oceans, as a whole, are warming. 3: Why is this mechanism unidirectional, when ENSO is oscillatory? 4: Assuming that a new unidirectional process must be a recent or temporary occurrence, otherwise we would have boiled or frozen awfuly quickly ... Why is your proposed physical mechanism a recent occurrence, when ENSO has been around for millennia, perhaps hundreds of thousands of years? 5: Why is the well-understood mechanism of an enhanced greenhouse effect from long-lived GHGs not operating according to their physics, despite this physics neatly explaining both present climate and palaeoclimate changes? To date I have not seen you directly tackle these absolutely crucial questions, despite several of them being asked on this thread.
51191. Bob Tisdale at 00:41 AM on 3 December 2012
       It's El Niño
       

       IanC says at 120: “Seriously, do you see yourself being wrong on the issue? do you see a possibility that your analyses are wrong?”

       IanC, with respect to my understanding of ENSO, I have investigated, discussed, illustrated, and animated the process of ENSO and its effects on global surface temperatures, ocean heat content and lower troposphere temperatures for almost 4 years. I have presented the effects of ENSO on sea surface temperature, sea level, ocean currents, ocean heat content, depth-averaged temperature, downward shortwave radiation, warm water volume, sea level pressure, cloud amount, precipitation, the strength and direction of the trade winds, etc. I have presented the multiyear aftereffects of ENSO on sea surface temperature, land-plus-sea surface temperature, lower troposphere temperature and ocean heat content data. I have created numerous animations. Everything I’ve investigated confirms my understanding of ENSO and its long-term effects.

       ENSO is a process. It cannot be accounted for by an ENSO index. Compo and Sardeshmukh (2010) “Removing ENSO-Related Variations from the Climate Record” seems to be a step in the right direction. They write (my boldface):

       An important question in assessing twentieth-century climate is to what extent have ENSO-related variations contributed to the observed trends. Isolating such contributions is challenging for several reasons, including ambiguities arising from how ENSO is defined. 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.

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

51192. Bob Tisdale at 00:35 AM on 3 December 2012
       It's El Niño
       

       John Hartz says at 123: “Please explain in one or two succinct paragraphs why you do not agree with the above statement.”

       Easy to do. I’ll cut and paste my opening comment on this thread, where the East Pacific data agrees with the WMO Secretary-General Michel Jarraud’s quote, but the Rest-Of-The World data does not:

       The East Pacific Ocean (90S-90N, 180-80W) has not warmed since the start of the satellite-based Reynolds OI.v2 sea surface temperature dataset, yet the multi-model mean of the CMIP3 (IPCC AR4) and CMIP5 (IPCC AR5) simulations of sea surface temperatures say, if they were warmed by anthropogenic forcings, they should have warmed approximately 0.42 to 0.44 deg C. Why hasn’t the East Pacific warmed?

       The detrended sea surface temperature anomalies for the Rest of the World (90S-90N, 80W-180) diverge significantly from scaled NINO3.4 sea surface temperature anomalies in 4 places. Other than those four-multiyear periods, the detrended sea surface temperature anomalies for the Rest of the World mimic the scaled ENSO index. The first and third divergences are caused by the eruptions or El Chichon and Mount Pinatubo. Why does the detrended data diverge from the ENSO index during the 1988/89 and 1998/99/00/01 La Niñas? According to numerous peer-reviewed papers, surface temperatures respond proportionally to El Niño and La Niña events, but it’s obvious they do not.

51193. Bob Tisdale at 00:33 AM on 3 December 2012
       It's El Niño
       

       In response to KevinC comment at 131:

       Thanks for your efforts. As you noted, it’s a great place to start a discussion. You seem to have created a great fit for the Mount Pinatubo eruption and the lesser ENSO events.

       KevinC says: “However we now only have one event. You can’t fit a pattern to a single event.”

       The 1997/98 El Niño was the strongest event and should have the cleanest signal, which makes your model versus Rest of the World graph look very awkward and unrealistic. (The fact that it should be the cleanest signal is why I keyed off the leading edge of the 1997/98 El Niño in my illustration.) Note how the other larger El Niño events in your model-data graph also don’t fit that well. If you would, please subtract the ROW data from your model to show how significant the residuals are.

       Therefore, for a really detailed analysis you’re attempting to perform, where you’re keying off all events, it’s likely you’ll need to isolate the East Pacific El Niño events like the 1986/87/88 and 1997/98 events and their trailing La Niña events. Why? The global temperature response to East Pacific El Niños (large events) is different from Central Pacific El Ninos (lesser events). That was the basis for the Ashok et al (2007) paper El Niño Modoki and its Possible Teleconnection.

       The reasons for the divergences in the Rest-Of-the-World data during the 1988/89 and 1998-2001 La Niñas are physical, KevinC. You can try to eliminate or minimize them using models, but they exist. East Pacific El Niños like the 1986/87/88 and 1997/98 El Niños release vast amounts of warm water from below the surface of the west Pacific Warm Pool. Much of that warm water spreads across the surface of the central and eastern tropical Pacific. For the East Pacific El Niño events, like those in 1986/87/88 and 1997/98, that warm water impacts the surface all the way to the coast of the Americas (while with Central Pacific El Niño events it does not). The El Niños do not “consume” all of the warm water. At the conclusion of an El Niño, the trade winds push the leftover warm surface water back to the West Pacific. Additionally, there is left over warm water below the surface that’s returned to the west Pacific and into the East Indian Ocean via a Rossby wave or Rossby waves. This animation captures a Rossby wave returning warm water to the West Pacific and East Indian Oceans after the 1997/98 El Niño. Watch what happens when it hits Indonesia. It’s like there’s a secondary El Niño taking place in the Western Tropical Pacific and it’s happening during the La Niña. It’s difficult to miss it. (The full JPL animation is here.) Gravity causes that warm water to rise to the surface with time. The leftover warm water exists and it cannot be accounted for with a statistical model based on an ENSO index. You can see—you can watch it happen—the impacts of that warm water in this animation. There are no ENSO indices that account for the leftover warm water.

51194. Bob Tisdale at 00:26 AM on 3 December 2012
       It's El Niño
       

       KR says at 124: “If as you say La Nina's absorb more heat (due perhaps to changes in cloudiness or other effects) than El Nino releases, how can this have driven warming since the 1970's? There has been a preponderance of El Nino events over that period (fewer than average La Nina events to raise total climate energy, esp. late 1970's-1998).”

       You need to look at surface temperature and ocean heat content separately, because they respond differently to ENSO.

       Let’s discuss surface temperatures first:

       KR, we agree on something. “There has been a preponderance of El Niño events over that period…” Glad you confirmed that ENSO has been skewed toward El Niño since the late 1970s. This means that more warm water than normal has been released from the tropical Pacific and redistributed, and it means that more heat than normal has been released to the atmosphere. That answers your question, “how can this have driven warming since the 1970's?”

       Now let’s address the ocean heat content portion of your question: “If as you say La Nina's absorb more heat (due perhaps to changes in cloudiness or other effects) than El Nino releases…”

       This makes itself known in the Ocean Heat Content for the tropical Pacific. The 1973-76 La Niña created the warm water that served as the initial fuel for the subsequent 1982/83 through the 1994/95 El Niño events, with the La Niña events that trailed those El Ninos replacing part of the warm water. That’s why the tropical Pacific OHC trend is negative from 1976 until the 1995/96 La Niña.

       The 1995/96 La Niña was a freak, and discussed in McPhaden 1999. “Genesis and Evolution of the 1997-98 El Niño”.
       http://www.pmel.noaa.gov/pubs/outstand/mcph2029/text.shtml

       McPhaden writes:

       For at least a year before the onset of the 1997–98 El Niño, there was a buildup of heat content in the western equatorial Pacific due to stronger than normal trade winds associated with a weak La Niña in 1995–96.

       In other words, there are parts of ENSO that cannot be accounted for with an ENSO index.

       The impact of the 1995/96 La Niña stands out like a sore thumb in the graph of tropical Pacific OHC. Then, moving forward in time, there’s the dip and rebound associated with the 1997/98 El Niño and 1998-01 La Niña.

       KR asks: “Why now? What has changed? The ENSO has been an existent pattern for perhaps hundreds of thousands of years. Why would it suddenly change behavior in recent years, when it hasn't in the past?”

       Paleoclimatological studies find evidence of ENSO back millions of years ago—not just hundreds of thousands of years. See Watanabe et al (2011). Your second question (“Why would it suddenly change behavior in recent years, when it hasn't in the past?”) is an assumption on your part. El Niño events were also dominant during the early warming period of the 20th Century, and global temperatures warmed in response then, too.

       KR asks: “Finally, what about the greenhouse effect?”

       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.

51195. Bob Tisdale at 00:20 AM on 3 December 2012
       It's El Niño
       

       michael sweet says at 122: My point is still valid, you must compare to the range of estimates, not the average.”

       NCAR and Gavin Schmidt disagree with you.

       The National Center for Atmospheric Research (NCAR)’s Geographic Information Systems (GIS) Climate Change Scenarios webpage has a relatively easy-to-read description. This quote appears on their Frequently Asked Questions webpage:

       Averaging over a multi-member ensemble of model climate runs gives a measure of the average model response to the forcings imposed on the model. Unless you are interested in a particular ensemble member where the initial conditions make a difference in your work, averaging of several ensemble members will give you best representation of a scenario.

       On the thread of the RealClimate post Decadal predictions, a visitor asked the very basic question, “If a single simulation is not a good predictor of reality how can the average of many simulations, each of which is a poor predictor of reality, be a better predictor, or indeed claim to have any residual of reality?”

       Gavin Schmidt replied:

       Any single realisation can be thought of as being made up of two components – a forced signal and a random realisation of the internal variability (‘noise’). By definition the random component will [be] uncorrelated across different realisations and when you average together many examples you get the forced component (i.e. the ensemble mean).

       We’re interested in the forced component, michael, not the noise, hence my use of the multi-model ensemble mean.

       michael sweet says: “Many other data sets exist that expand the time period of your analysis. It has been shown by others in this thread that you cherry picked the data set you used.”

       I cherry-picked my dataset? Since I must have missed the comments you’re referring to, let me answer your and their comments now. Maybe you’re referring to a comment by IanC. I replied to him, Why aren’t we looking at the sea surface temperature data prior to the satellite era? Because there’s little source data south of 30-45S. Here’s a map that illustrates the ICOADS sampling locations six months before the start of the Reynolds OI.v2 dataset:
       http://i47.tinypic.com/k2g6bs.jpg

       Same map for June 1975:
       http://i49.tinypic.com/73040z.jpg

       And it doesn’t get better as you go back in time. Here’s June 1943:
       http://i49.tinypic.com/2eb8sb8.jpg

       And to further respond to your accusations of cherry-picking, michael sweet, are you aware that HADSST2 and HADSST3 are spatially incomplete during satellite era? Are you aware that NOAA’s ERSST.v3b has to be infilled during the satellite era because it does not use satellite data? Are you aware that Smith and Reynolds called the Reynolds OI.v2 dataset the “truth”? Refer to Smith and Reynolds (2004) Improved Extended Reconstruction of SST (1854-1997). It is about the Reynolds OI.v2 data we’ll be using as the primary source of data for this book:

       Although the NOAA OI analysis contains some noise due to its use of different data types and bias corrections for satellite data, it is dominated by satellite data and gives a good estimate of the truth.

       The truth is a good thing, don’cha think?

51196. Bob Tisdale at 00:18 AM on 3 December 2012
       It's El Niño
       

       Tom Curtis, in your comment 80, you presented your findings about the significance (the lack thereof) of the lack of warming in the East Pacific sea surface temperature data versus the IPCC model hindcasts/projections. A recent post at Niche Modeling titled East Pacific Region Temperatures: Climate Models Fail Again found precisely the opposite, as you may have guessed from the title of the post.

51197. ranyl at 23:43 PM on 2 December 2012
       Subcap Methane Feedbacks, Part 1: Fossil methane seepage in Alaska
       http://www.pv-magazine.com/news/details/beitrag/thin-film-solar-market-to-grow-1500-percent-by-2017_100004524/#axzz2DlT7sIK0 This article suggest thin well on the rise 1500% from above. And the articles age spread was deliberate to shpow that things have been to be toxic for ages and still are. And what si said dosn;t jsut apply to thin that is just tri-ntiroforide and as you well know any silicon used to pureifed to >99% pure. And the maximum efficiency on practice is 12-15%. But hey beleive what you like abotu them, we still have any carbon to spend oon then when other options are much better, like not using so much power.
51198. dan7912 at 20:09 PM on 2 December 2012
       Climate's changed before
       wow, I trawled through a lot of this some fascinating battles going on, and none dispassionate. On the one hand it seems scientists are fitting hypotheses around one data set (CO2) when the earth could be observed as a much more intricate system with too many observable forces than one.It depends how you look at it I suppose. It's like they're trying to find a theory of everything. I do reckon the industrial system produces too much stuff causing pollution in the atmosphere like satellites, what's the carbon footprint on a couple of satellites? I think if we all just slowed down a bit, stopped our industrial systems and stopped funding university's and science programs, life would be less splintered and more holistic and we could observe the natural rythyms of life and ourselves. also its very fatalistic, you can make all this effort and then a solar comet is just round the corner at any given moment/ like in the plastacene era. Whats the point of all the scaremongering. Think of the children guys.
51199. Clyde at 17:56 PM on 2 December 2012
       The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
       @dana1981 - 10 Hyper linked from the link you claim i never read. But the issue is far from settled, and climate change is not the only factor. For example, while sea surface temperatures are currently about 3 °C above average along the Atlantic coast, the expected increase due to global warming is just 0.6 °C, according to Kevin Trenberth, a climate scientist at the National Center for Atmospheric Research in Boulder, Colorado. So while the changing climate certainly plays a role, Trenberth says, there is plenty of space for natural variability. Looks like Trenberth agrees with me. Nobody can say how much a role GW played. On the link you claim i didn't read. "While it’s impossible to say how this scenario might have unfolded if sea-ice had been as extensive as it was in the 1980s, the situation at hand is completely consistent with what I’d expect to see happen more often as a result of unabated warming and especially the amplification of that warming in the Arctic" Trenberth said that the null hypothesis would be that the negative North Atlantic Oscillation was just part of the oscillation's natural phases, and at present the influence of polar warming was speculative. There is actually a fairly simple answer to this question: human-caused climate change amplified the hurricane's impacts. My question is by how much? If there was no GW would Sandy's damage been mild compared to what is actually was? So for news article to say GW caused Sandy to do X amount of damage is "Gish Gallop." I'm not saying GW had zero effect on Sandy. I'm just saying it can't be proved how much of an effect it did have, nor can it be proven what Sandy would have been like say in 1980. Was the climate a whole lot different in 2011? Why didn't Irene turn into a Sandy?
51200. Brian Purdue at 16:36 PM on 2 December 2012
       The Latest Pre-Bunked Denialist Letter in Lieu of Real Science
       I often wonder what it will take for people like Clyde to even consider there might be human-induced climate change, in the absence of natural causes. The climate is made up of weather events. Climate change is their duration, severity and their frequency. I can only speak for where I live, but the pattern is world-wide. In Australia, the following are “some” of weather-related events in the last three (3) years. # Victorian “firestorm” bushfires killed 173 people and burnt down over 2000 homes. It was hotter in the howling winds than out and; # A 1,000 kilometer-long thick chocking red-dust storm swept from central Australia, across the east coast and went as far as New Zealand and; # Record Queensland, New South Wales and Victorian floods that caused a “tsunami” on top of a mountain range. These floods required a national flood levy to be set up by the federal government and; # Category 5 cyclone Yasi slammed into North Queensland and; # Record- breaking sea temperatures in the oceans around Australia and; # Record-breaking dry period in central Australia -147 days and; # Record-breaking land temperatures around Australia, with record temperatures for November in parts of Victoria only 2 days ago. The clear evidence shows no sign of slackening.......

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