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Dikran Marsupial at 19:35 PM on 23 July 2011It's Pacific Decadal Oscillation
Eric the Red So after all this, it seems your position is that ENSO causes short terms fluctuations in surface temperatures and we need to consider this in attributing climate changes to the various forcings? That has been known for a very long time and news to nobody. It is the "skeptics" you need to be telling that to, as it is them that use the fluctuations of ENSO to cherry pick arguments such as "did global warming stop in 1998". The effects of ENSO are fairly straightforward to remove via regression, giving results like this
It seems to me you have just been backing away from your original point about PDO as people have refuted your argument and ended up arguing for a completely bland position that we all argee with anyway, and which has virtually nothing to do with PDO!
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damorbel at 19:15 PM on 23 July 20112nd law of thermodynamics contradicts greenhouse theory
Re #1080 Tom Curtis you write:- "2) Transfer of energy by convection is essential to understanding the modern theory of the green house effect. In this case it is not essential to the effect itself, in that in principle you could have a green house effect without it." Which is what I interpret as 'the adiabatic compression effect of gravity on the atmosphere' This is modest (55K) on Earth but severe (400K) on Venus with its x90 atmospheric mass. Are you able to distinguish between this compressive heating of the surface and the GH effect?. For me this is critical to the understanding of atmospheric physics and not often discussed. For example, in your post #1080 you have a diagram of atmospheric temperature profile with two T vs H gradients, one for 'CO2' and another for '2xCo2'. From your diagram both gradients appear to be the same i.e. the amount of CO2 does not change the gradient, only the surface temperature. From this diagram I cannot derive a clear understanding of how changes in the concentration of atmospheric CO2 influence the surface temperature. -
Rob Painting at 18:25 PM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
David, note this bit from the Solomon (2011) paper "Near-global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about –0.1 W/m2, reducing the recent global warming that would otherwise have occurred." Ties in with the title of my post very well methinks. Of course, they're referring to volcanic stratospheric aerosols, a separate issue. Certainly interesting stuff. -
Tom Curtis at 16:29 PM on 23 July 2011OA not OK part 6: Always take the weathering
scaddenp @23, Crowded House was an Australian band, formed in Melbourne, no less. Granted the genius behind it was a Kiwi. -
Doug Mackie at 16:27 PM on 23 July 2011OA not OK part 6: Always take the weathering
Are you referring to this "Australian" band? What kind of dirty creature would stoop to that sort of cultural appropriation? It makes me see red 8-) -
David Lewis at 16:20 PM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
The Solomon paper is suggesting that stratospheric aerosols are persistently variable, and assessments such as UNEP, something Solomon was one of ten lead authors of, affirm that: "there is no long term systematic global monitoring system to document long term future changes in stratospheric aerosols that could affect ozone and climate" so they are basically saying this is a factor models will have to take into account if they want to increase the possibility they might get accurate one day, based on impressions of the data they could get their hands on. But with data assessed to be like this, what would they suggest a modeller do? Toss a coin? Maybe that's why Hansen just asked his grandchildren.... I thought if the volcano people didn't think there was an increase in global volcanism it might mean they don't think there has been an increase in tropical volcanism. The Vernier paper abstract suggests an increase in volcanism but doesn't say increased compared to anything in particular. They mention the Brewer-Dobson circulation which might mean they feel they've observed something new there - The UNEP assessment discusses this circulation: "the Brewer Dobson circulation is not a measureable quantity and hence trends... are inferred...." "climate model simulations consistently predict an acceleration of the Brewer-Dobson circulation in response to increasing greenhouse gases..." although not predicted to be detectable yet "Certainly any change in the strength of the Brewer-Dobson circulation would alter the thermal structure of the stratosphere." It might be that volcanoes of a size that weren't thought to be powerful enough to be injecting material directly into the stratosphere, because of a misunderstanding of how Brewer-Dobson circulation works, or because it has changed, are suggested to be injecting material by Vernier. The Brewer-Dobson circulation is the way air circulates from the troposphere to the stratosphere and back.... -
scaddenp at 15:41 PM on 23 July 2011OA not OK part 6: Always take the weathering
Would anyone who not a NZer spot the referencing in the title of this part? (I assume its a take on "always take the weather"?) -
Rob Painting at 15:38 PM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
David Lewis - your link doesn't enlighten us as to the degree of tropical volcanism. This is important because nearer to the equator and the plumes can reach high up into the stratosphere. That's not the case for volcanoes at high latitudes. Furthermore the studies mentioned actually go into a lot more detail, such as satellite observations. -
David Lewis at 15:16 PM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
The Global Volcanism Program has a page "Has volcanic activity been increasing?" They say "we don't think so". A dramatic increase in volcanoes per year has been reported for centuries apparently, but they say this is due to more reporters rather than more volcanoes. -
Sarah at 15:02 PM on 23 July 2011OA not OK part 8: 170 to 1
Jeff, Figure 3 could be made with the Y-axis in terms of concentration instead of fraction and it would look the same. For example, instead of 1.0 it the value could be 2100 x10-6 mol kg-6. Adding more carbon to the system would make all three lines increase together. So, if the new concentration is 10% higher (it isn't in the real world!) all three lines would be 10% higher on that scale but their proportions would stay the same. Another way to think about this is to consider the CO3-2 line at around pH 8.1. If you add a significant amount of CO2 then all three lines go up when the Y-axis is in concentration units. But, by eqn 12, adding CO2 causes some of the CO3-2 to convert to HCO3- and the new distribution defines a new more acidic pH. Actually, the 2% increase in ocean carbon would only shift the concentration lines up (together) by a tiny amount (2%). But because the system at pH 8.1-8.2 is far down on the slippery slope of low carbonate, it makes a big change in percent CO3-2. Your suggestion that the ratio is more important than the concentration for defining the pH is correct. The complication is that in this system carbon is both the main thing controlling the pH (by the ratio of bicarbonate/carbonate) and the thing making the pH shift (because CO2) in water make carbonic acid, which reacts with carbonate to change the ratio, eqn 12). Neither the figure nor the post are "using only three equations to define four parameters". They are using the equations to understand the behavior of the system as a function of pH (H3O+). If you want to calculate the pH for a system containing these carbon species, then the equation you need is: 2H2O --> H3O+ + OH-. pKa=14. -
Doug Mackie at 14:44 PM on 23 July 2011OA not OK part 8: 170 to 1
Jeff, Are you the Jeff T who supports Piers Corbyn? If so, it would explain a lot. If not then consider what you have said again about the number of components and equations. What happens if you have 4 doors to open with 4 keys but the keys are mixed up? Once you have correctly identified 3 of the keys do you need to test the 4th key to identify its door? The figure shows that the components are not independent. The equations link them. All aspects of the CO2 system can be described by any two of the composition parameters. e.g. CT and pH are sufficient to determine AT, pH and CO2. Your inability to understand the figure does not appear to be widely shared. By all means prepare a figure yourself and post it here. -
Eric the Red at 14:11 PM on 23 July 2011It's Pacific Decadal Oscillation
Tom, In essence we agree. There are no long term consequences from an ENSO fluctuation, but the effects are evident in the short term. The fluctuations do not produce a "step change," but rather a relatively smooth transition. -
Doug Mackie at 13:44 PM on 23 July 2011OA not OK part 9: Henry the 8th I was (*)
Lazy teenager @2: Degree of disequilibrium depends on the set of K values - see previous post. Ocean as a source: see next post. -
Keith Hunter at 13:35 PM on 23 July 2011OA not OK part 9: Henry the 8th I was (*)
LT @1: they amount to the same thing. Henry's Law describes the equilibrium solubility of a gas for a given atmospheric concentration. A fizzy drink is made by pressurizing the bottle with a high pressure of pure CO2. hence it has a high solubility. When the bottle is opened to the air, Henry's Law dictates that the concentration of CO2 is now too high too be in equilibrium with the new air space, so CO2 must escape from solution, hence bubbles. A related factor is that fizzy drinks are pressurized when cold to give a higher solubility. This is because the Henry's Law constant changes with temperature (as do all equilibrium constants). -
Jeff T at 13:32 PM on 23 July 2011OA not OK part 8: 170 to 1
Christina, I guess my difficulty with the post arises from the fact that it includes only three equations (8, 9 and total carbon content = sum of carbon species) to determine four parameters (concentrations of H3O+, CO2, HCO3- and CO3--). Since Eq. 12 is the difference between Eq. 8 and 9, it doesn't provide a fourth independent relation. I suppose that you don't give a fourth equation because there are really many relations and species concentrations required. As I said, I appreciate the effort, but I don't think you've solved the problem of presenting the issue clearly. Sarah, the example computation following Figure 3 assumes that total carbon content is constant. That's why it shows a decrease in concentration of CO3--. Wouldn't an example that decreases pH by adding total carbon show an increase in CO3-- concentration, even though the ratio of CO3-- concentration to other carbon species would decrease. It may be that the ratio is more important than the concentration, but the post doesn't say so. It would be informative to remake Figure 3 to show the fractions (or concentrations, whichever is more important) of the three carbon species as a function of the total CO2 added to pre-industrial seawater. -
Tom Curtis at 13:04 PM on 23 July 20112010 - 2011: Earth's most extreme weather since 1816?
Norman @373, now that I understand that your analysis is explicitly related to the formation of supercells in the United States, I will modify my criticism from 262 and 268 above. Specifically, for that question, your sample points are sparse but can make a reasonable claim to be representative. However bundling data without regard to season and ENSO index still means your analysis is ineffective. If you really want to do citizen science on this, I have to commend you but don't imagine for a second that it is easy. In science you don't get to skip corners, and a proper study will involve multiple thousands of pieces of data, and very careful analysis. If you are not prepared to put that sort of work in, your analysis will inevitably be both shallow and flawed. What is more, it will be irrelevant because genuine climatologists and meteorologists have put in the real work, collecting tens (probably hundreds) of thousands of pieces of data, and analyzing it carefully in peer reviewed literature where any obvious and, most likely, any subtle flaw has been pounced upon by somebody with a passion for truth or to make a name for themselves. So in order to accept your conclusions from your analysis, we would have to turn our back on a great deal more data, subject to a far more rigorous analysis. Not that I am trying to discourage you from your three city analysis. I am a great fan of such analyses so long as their role is understood. That role is to learn, not to discover. By undertaking such an analysis you can more quickly gain an appreciation of the issues involved than by any other method (other than a good lecture). But you will only do so if you understand the true nature of expertise, which is knowledge of the obvious errors in a field, and how to avoid them. Think about it. You and I are not expert in meteorology. Ergo we are likely to make obvious blunders and not realize it. In contrast, genuine experts (like Albatross) will probably also make errors, but they will be subtle and interesting errors. That is, errors that are hard to avoid, and which you learn a great deal by uncovering. So the obvious attitude you and I should take is that when we disagree with the experts, we should first check rigorously why we are wrong. Not the experts, but we ourselves. Only after checking rigorously enough to become competent in the field ourselves, and after floating the idea with a few experts, a significant proportion of whom then agree with us, should we even begin to suspect that we are right. Even at that stage history shows that we are probably still making an error, but at least it will be an interesting and subtle error. Frankly, that has not been your attitude on this or any other thread on Skeptical Science. That is why Albatross is so frustrated. It is not that you keep on asking questions, a behavior which delights most experts. Its that you don't accept answers. -
Norman at 13:00 PM on 23 July 20112010 - 2011: Earth's most extreme weather since 1816?
KR @ 365 Can't leave without this one. From your link to the peer-reviewed material on climate change. "There are no indications in this study of more intense storms in the future climate, either in the Tropics or extratropics, but rather a minor reduction in the number of weaker storms." There is significant changes to storm tracks. The thesis of this thread is "2010 - 2011: Earth's most extreme weather since 1816?" The peer reviewed article does not see an increase in the intenstity of storms, only a change in location of storms. No change in intensity of storms. -
Norman at 12:53 PM on 23 July 20112010 - 2011: Earth's most extreme weather since 1816?
Tom Curtis @ 368 Side note: To Albatross, you stated this thread has run its course. So unless someone else wishes to discuss more I will end here and go to read the Ocean acidification series (more in my field). Just wanted to respond to you Tom. You say: "Norman @363, I am not interested in debating the issue with you. Anyone who has followed this thread knows you are only interested in coming to the conclusion you started with. This is made perfectly plain in your 359 (among many other places). When looking for signs of recent increases in extreme weather you come across an extraordinary example, and immediately interpret it as proof that extraordinary examples of recent extreme weather are not evidence of increasing extreme weather. It certainly, to your mind, had nothing to do with the 2-4 degree anomaly in the US at that time. It turns out that through out the course of this debate, for you , nothing can be." I would think if would have nothing to do with the 2-4 degree anomaly in the US in January 1999. Here is why. January 1999 anomaly map. (Sorry I am not posting the graphs directly, I attempted it once but found my skill at this lacking.) February 1999 greater heat anomaly than January. January 1999: 212 tornadoes February 1999: 22 tornadoes More: January 1998 had 47 documented tornadoes. January 2000 had 21 documented tornadoes. If you do check out each of the linked maps to tornado number you can see all these years had strong temperature anomalies in January. But January 1999 soars far above the others. You would really have to stretch something to prove a causal link between January temps and tornado count in the US. Final link Does this sound sort of simialr to the topic of this thread, just switch 2010 to 1999 and there could be a match. History repeats. -
Rob Painting at 12:52 PM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
Papy - ta, already have that Solomon (2011) paper. Seems that a clutch of papers on aerosols have been published very recently. Myself and a couple of other authors are discussing them at the moment. Should have some posts on them shortly. What specifically interests me is what effect (if any) the Asian (& volcanic) aerosols may have had on ENSO, and the uptake of heat into the oceans. -
Norman at 12:28 PM on 23 July 20112010 - 2011: Earth's most extreme weather since 1816?
KR @ 365 "On the other hand, I have to seriously criticize you for continuing to choose single or several site data sets to discuss global averages." In the series of posts above, I was not attempting to discuss global averages. Tom Curtis made the statement: "As Norman correctly points out, humidity alone is not enough for a thunderstorm; but heat and humidity are both definite factors in the strength of thunderstorms. If you increase both, ceterus paribus you will increase the frequency and intensity of thunderstorms. As it happens, increased warming is also expected to increase Convective Available Potential Energy, another key factor (see maps in my 246." I was attempting to demonstrate his point "If you increase both, ceterus paribus you will increase the frequency and intensity of thunderstorms." was not the case. In my series of posts the point was to show Tom that only a threshold humidity and heat are needed to initiate severe thunderstorms. The rest of the equation is unstable air (cold heavy air mass on top of less dense warm air). The more unstable the air, higher temp gradient between surface warm air and cold air aloft, the greater is the chance for severe weather. If you get a strong wind shear you also increase the chance for tornadoes. I did agree with Tom that if, in the United States, you would be able to send the higher energy July or August air into the unstable air of May, you would indeed create more severe storms than what are currently taking place. Your claim: "You've accounted for a significant percentage of the posts on this thread, and you have been consistently wrong. Worse, you don't seem to understand the criticisms raised. I would strongly suggest you step back and review what you know, and what you don't know, before posting here again." It is easy to say I am consistently wrong. Can you show how any of my links are not correct? Can you demonstrate that the month of May does not produces the most severe storms in the US? From your link: "How does one counter the Dunning-Kruger effect, in others or in themselves? Dunning and Kruger propose that improving a person's skills helps them recognise the limitations of their abilities. If there's a question about an aspect of climate science, the first step should be to investigate and improve understanding of the science. Odds are climate scientists have investigated the same question in the peer-reviewed scientific literature." KR, I do believe I have been doing this. Thanks to the intelligent and knowledgable Tom Curtis, Albatross, Daniel Bailey, Dikran Marsupial and many others I have recognized many flaws in my understanding and holes in my knowledge base. I have been attempting to investigate and improve my understanding of the science. I try to find peer-reviewed material for my posts, avoid blogs. One of my main reasons for posting on a scientific web site like this one. I am seeking more than one person's opinion on the issue. I want good science. From your link: "If there's no direct answer, find the closest topic and post a comment asking for answers. There are many well informed regulars who would be happy to point you towards any relevant peer-reviewed papers." My question is this: Why would weather events get more extreme when Global warming is pushing the Earth towards and equilibrium state (poles warming about twice as fast as tropics). I have been linked to articles where a computer model predicts more severe weather much later in this century. There is no way for me to validate the model. All I can determine for sure is maybe it will happen. But it does not answer my question above. I have found many sources that explain severe weather is caused by unstable air mass. You need cold air to develop this condition. If the poles are warming twice as fast as the source of the warm, moist fuel, then why wouldn't the instability of the atmosphere decrease as the Globe warms? It would have less cold air available to create the unstable air that generates severe weather. You also said: "But, please, stop selecting one to three spots in the USA only, and claiming that they mean anything compared to the global data. It's incorrect, statistically meaningless, and rather sad to watch" I think you are not understanding what I am attempting. In order to demonstrate a physical mechanism you do not have to go to every spot on earth to prove the condition is global. I am demonstrating that a reserve of cold air is necessary for the formation of most severe thunderstorms (there are always exceptions). If the reserve of cold air is reduced then the number and intensity of thunderstorms will be reduced. I choose points in Oklahoma and Texas because these are the areas that produce the most severe thunderstorms not just locally but globally. I demonstrate that May has the most severe storms in those states (tornadoes, rain, hail). I demonstrate that without the cold air aloft the highly energetic and moist air of July and August do not produce near the number of severe storms or rain events. If you drop a ball in your house and have supporting documentation of gravity, do you need to come to my house and drop a ball to test the idea? If I can demonstrate that warming of air in Texas and Oklahoma will not lead to more severe storms (over a 100 year period for precipitation and at least 50 years for tornadoes), why would I need to extend the area? I am demonstrating a mechanism that is supported by the literature (I have linked to multiple sources which confirm the mechanisms needed to produce severe storms). If the mechanism is a valid one, it will work anywhere on the globe. -
Norman at 11:43 AM on 23 July 20112010 - 2011: Earth's most extreme weather since 1816?
Tom Curtis # 370 "Norman @367, I do not believe that I have ever said that warm moist air is the major ingredient in the formation of severe weather." What you had said "From an earlier post by Tom Curtis at 258 "As Norman correctly points out, humidity alone is not enough for a thunderstorm; but heat and humidity are both definite factors in the strength of thunderstorms. If you increase both, ceterus paribus you will increase the frequency and intensity of thunderstorms. As it happens, increased warming is also expected to increase Convective Available Potential Energy, another key factor (see maps in my 246" That is where I misquoted you, sorry. You used the words "definate factors" and I switched that to "major ingredients" also you said "thunderstorms" and I changed that to "severe weather". My flaw. I stand corrected. -
Doug Mackie at 11:05 AM on 23 July 2011OA not OK part 8: 170 to 1
Thank you Sarah. We did think about a more complex figure with multiple axes that included changing total carbon but we felt it would not have been easily understood. -
Papy at 10:49 AM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
If so and to complete, there seems to be a complementary study in my french source of the "Institut Pierre Simon Laplace" : "The persistently variable « background » stratospheric aerosol layer and global climate change" (Solomon et al, 2011). -
Sarah at 10:25 AM on 23 July 2011OA not OK part 8: 170 to 1
Jeff T: Figure three shows the distribution of carbon in the three forms when the pH is at different levels no matter what makes the pH change. If you put carbonate and/or bicarbonate in a beaker and then add nitric acid the proportions of each form of carbonate will change. The proportions will also change if you add any other acid, hydrochloric acid, acetic acid (vinegar), or carbonic acid. If you use CO2 to lower the pH then the fractions behave just like the figure shows, even as the total amount of carbon increases. You can also increase the pH by adding any kind of base, for example sodium hydroxide. And you can increase the pH by adding carbonate (CO332-). In that case the total amount of carbon also increases while the fractional distribution shifts to the right on the graph. Removing CO2 decreases the pH (by eq 8 it removes H3O+) and so the fractional distribution again shift right, even though this time the total amount of carbon decreases.. Figure 3 is very powerful precisely because it separates the total amount of carbon from the fraction in each form. -
LazyTeenager at 10:01 AM on 23 July 2011OA not OK part 9: Henry the 8th I was (*)
So the next thing to find out is whether seawater is above or below the equilibrium amount in CO2. A nice global map would be nice. Seems to me that some in climate sceptic land have seized on the idea that the ocean is emitting CO2, but I suspect this idea is a matter of faith for them and not based on evidence. -
LazyTeenager at 09:49 AM on 23 July 2011OA not OK part 9: Henry the 8th I was (*)
Correct me if I am wrong but I would have thought that the fizzing of carbonated water relates to the solubility (maximum dissolvable amount) of CO2 in water and not to the Henry's law equilibrium. The temperature dependence would be in the same direction but the actual relationship would be different. -
Tom Curtis at 09:39 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric the Red @114, again to just make sure we are on the same page, unless the climate system is very close to a tipping point (within 0.2 degrees c), ENSO fluctuations cannot result in a "step change" in global mean temperatures. Another way to look at it is this, if you have a period of predominantly La Ninas and follow with a period of predominantly El Ninos, in a period of no underlying trend, in the immediate period of the transition that will introduce a spurious trend to global mean temperatures. But outside of any interval that ranges across the point of transition, that change will introduce no trend to the series. Do you agree? I believe that this is a straightforward conclusion from the fact that there are no long term consequences from an ENSO fluctuation. I am seeking this clarification because you qualify your response by mentioning La Ninas, whereas the lack of long term effect of an El Nino is independent of any follow on La Ninas. -
Rob Painting at 08:46 AM on 23 July 2011Why Wasn't The Hottest Decade Hotter?
Papy - thanks for the Vernier (2011) abstract link. I'll see if I can track down a copy of the paper - it might be worth a post. -
Doug Mackie at 08:02 AM on 23 July 2011OA not OK part 6: Always take the weathering
Hi Paul, I see that Doug (comment 20) suggested you calculate the pH of rainwater in order to answer your question about the change in rainwater pH (comment 19). How did you go with this? You are correct - biochar soil remediation may help reduce atmospheric CO2. However, it is unlikely that the carbon sequestration would be any faster than the 150 years it has taken to put the CO2 into the atmosphere. This is unlikely to reverse ocean acidification (the topic of these posts) in any remotely useful time frame. -
Eric the Red at 06:40 AM on 23 July 2011It's Pacific Decadal Oscillation
Sphaerica, You still have a time frame when the ENSO index is essentially zero. The goal posts have not moved. As I stated previously, the period starting in 2007 may suffice, if it persists. Something similar to 1950 - 1977. -
Byron Smith at 06:08 AM on 23 July 2011China, From the Inside Out
@Paul Magnus: Regarding not flying and people listening, I have had precisely the same experience. -
Bob Lacatena at 04:55 AM on 23 July 2011It's Pacific Decadal Oscillation
123, Eric the Red, Gee, how very nefarious of me. Okay, lets start at 1995, which was during an El Nino, and includes the world temperature record 1998 El Nino at the start of the period. We'll end in 2009 (during a La Nina).
or, if you prefer, we can end in 2010, again in the midst of a moderate La Nina.
Any other cherries you'd like unpicked?
Response:[DB] Perhaps this is relevant?
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Albatross at 04:39 AM on 23 July 2011It's Pacific Decadal Oscillation
Sorry, please replace "Tom" with "Sphaerica" in #124 above. Sorry Sphaerica! -
Bob Lacatena at 04:38 AM on 23 July 2011It's Pacific Decadal Oscillation
118, Eric the Red, So the goal post moves from "in the face of repeated La Ninas" to "a period of predominately La Nina." Which means what? We have to wait until the roll of the dice generates a period with 8 out of 10 years being in a La Nina phase in order to prove to you what all of the evidence, logic, numbers and statistics already show? This is equivalent to my recent question to you about what it would take for you to accept AGW, and your answer was a temperature increase over the next 26 years equal to that of the past 26 years (meaning you will admit to nothing until 2037). -
Albatross at 04:38 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric, Thanks for dragging this discussion down. I can assure you that Tom is not in the habit of cherry-picking. You asked for a period satisfying certain conditions, and he found one (starting in 1999) and then presented the UAH data for that period. I then checked the MEI data for Tom's window and the mean MEI was in fact negative, so was the ONI. So you are making ridiculous accusation-- the very nature of your request made it necessary to identify a time window when the ENSO was predominantly negative (La Nina) but during which the planet warmed. So instead of accepting the evidence as a true skeptic would do, you start making fallacious accusations. IMHO you owe Tom a sincere apology. -
Eric the Red at 04:31 AM on 23 July 2011It's Pacific Decadal Oscillation
Albatross, I was using Sphaerica's orange box which appears to encompass the timeframe 1998-2011. He conveniently changes to 1999 for his temperature plot, thereby removing the highest values from 1998, and arriving at his cherry-picked trend. This is one of the fallacies of using short-term data. Had he chosen a similar start date for his temperature plot, he would have a negative trend. -
Rob Honeycutt at 04:21 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric @ 121... Well, I wonder if you removed changes in solar forcing if you'd start to see that accelerating trend. You'd also have to remove Asian aerosol effects as well. I think there are probably a lot of reasons to think the underlying CO2 induced warming trend is, indeed, accelerating. -
Eric the Red at 04:11 AM on 23 July 2011It's Pacific Decadal Oscillation
Dikran, Yes! When the PDO or ENSO signal is removed from the temperature records, the oscillation disappears, and a fairly linear increase results. There has been no acceleration nor deceleration, and no reason to expect any. -
Albatross at 04:09 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric claims "The composite ENSO index for your entire boxed area is just slightly below 0 (in fact it was positive until March, 2011)" It is not clear exactly which period we are referring to, Tom seems to have plotted those UAH data from January 1999 onwards. The mean MEI for 1999 (Jan/Feb)- present (May/June) 2011 is -0.085. The mean MEI until Feb/March was -0.24. The ONI also give negative mean values between January 1999 and March 2011, and until June 2011. Yet, the planet has warmed. Eric, you are arguing/debating in circles, and it would really help if you backed up your assertions with data and citations-- like the extreme thread, you are again talking though your hat here. Note how the global temperatures associated with the 2007-2008 La Nina were warmer than those in 1999-2000, and how global temperatures during and shortly after the 2010-2011 La Nina were warmer than both previous events. It will happen relatively soon (within a decade or so) that even a year with a moderate of strong La Nina will be warmer [Global temperature anomaly, GTA] than 1998, a year with a the second-strongest El Nino on record. In fact, the planet was warmer in 2008 (La Nina, GTA = +0.44 C), 1999 (La Nina, GTA = +0.32 c) and 2000 (La, Nina GTA = +0.33 C)were all warmer than 1983 (El Nino, GTA = +0.25 C), and 1983 was the year of the strongest El Nino on record. ENSO etc. are oscillations superimposed on a long-term underlying warming trend because of the radiative forcing from anthro GHGs. They can modulate the trend, and that is it. -
Dikran Marsupial at 03:57 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric the Red There appears to be a contradiction here, perhaps you can explain. If PDO does not cause warming, then there is no reason to think that there is a genuine oscillation in temperatures due to the PDO (and instead it is either a coincidence or the causal relationship is in the other direction). In that case there is no reason to think that the current upward swing of PDO is causing the acceleration (what acceleration?) in the upward rise of temperatures. I should point out that there have been several regression alanyses performed (and discussed at SkS) where the effects of ENSO are removed from the temperature time series and you get a pretty steady approximately linear rise in temperatures. A linear rise in temperatures is exactly what you would expect from an exponential rise in atmospheric CO2. -
Eric the Red at 03:27 AM on 23 July 2011It's Pacific Decadal Oscillation
Dikran, It is not a matter of either CO2 or PDO is causing warming. During the past 130 years, the CRU temperature record has shown an increase of ~0.6C / century. Overlain on this increase are two 60 year cycles with an amplitude of ~0.3C. The oscillation is not affecting the underlying trend. Some people are preferring to ignore the oscillating effect and claim that the temperature rise has accelerated during the upward cycle. This has led to some added explaining during the recent period. Sphaerica, notice how the temperature responds to the ENSO index? La Nina conditinos from 1999-2001, El Nino for the next 5 years, La Nina in 2008-9, El Nino in 2010, La Nina in 2011. The composite ENSO index for your entire boxed area is just slightly below 0 (in fact it was positive until March, 2011), so it does not constitute a period of predominately La Ninas. If we see repeated conditions such as existed from the end of 2007 forward continuing, then I would agree. We need a warm summer, since the first 5 months of 2011 were the second coldest during your orange box (2008 being colder). -
Rob Honeycutt at 03:10 AM on 23 July 2011It's Pacific Decadal Oscillation
Sphaerica... That chart gets even more interesting if you plot it with a 12 month mean. [Here.] -
Bob Lacatena at 03:00 AM on 23 July 2011It's Pacific Decadal Oscillation
114, Eric the Red,In answer to Sphaerica's question, it would take a period of rising temperatures in the face of repeated La Ninas for me to abandon the idea that ENSO (or PDO) has a climate impact.
Good. It's settled, then. See 2000-2011. 4 strong La Nina's (boxed in orange):
Rising temperatures:
I should point out that we're currently on a path to the second warmest summer ever, despite the recent end to a moderate La Nina, and without El Nino conditions... and during the cool phase of PDO (which supposedly started in 2008).
Current Temps
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Dikran Marsupial at 02:56 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric the Red wrote: "I am not arguing the this [judging from context ENSO] is responsible for the 20th century warming." If you are arguing that PDO has an effect on climate then yes you are, becuase the correlation we have been discussing is between PDO and the surface temperature record, which is pretty much the 20th century (with a few decades hanging off the ends). "My point is that during the short term, this oscillation can affect temperatures," In that case it is a pointless point as pretty much everybody with an interest in climate know perfectly well that ENSO has an effect on surface temperatures. It is perhaps not surprising you are being misunderstood. If your point was about the short term effects of ENSO, then it was probably a bad idea to talk about PDO which is the long term behaviour of ENSO. -
Eric the Red at 02:41 AM on 23 July 2011It's Pacific Decadal Oscillation
Tom, Thank you for that in depth response. I agree that the long term climatic effects of ENSO variations is 0. Over time, warm El Nino years (2010) are balanced by cold La Nina years (2011). Over the past century, we have had periods of stronger and more abundant El Ninos, which were characterized by higher temperatures, followed by periods of stronger and more abundant La Ninas, resulting in cooler temperatures. These cycles can be overlain atop the warming trend of the 20th century. This is not unlike what Tamino has done with his recent analysis with aerosols and ENSO. The ENSO index was largely positive, with an abundance of EL Ninos from 1977 - 1998. Prior to that, it was largely negative, with an abundance of La Ninas. Since then, we have fluctuated between the two without a strong signal until this year's strong La Nina. In answer to Sphaerica's question, it would take a period of rising temperatures in the face of repeated La Ninas for me to abandon the idea that ENSO (or PDO) has a climate impact. I am not arguing the this is responsible for the 20th century warming. My point is that during the short term, this oscillation can affect temperatures, and should not be confused with other factors. There are some on this thread that seem to think that just because I acknowledge these effect that I believe that the entire post-industrial warming was due to PDO. That is simply not the case. That would be like saying that Hansen believes the entire observed warming was due to the changes in aerosols, because he claims the recent emissions by China have cooled temperatures. -
Dikran Marsupial at 02:32 AM on 23 July 2011It's Pacific Decadal Oscillation
Eric the Red I think you have also misunderstood Sphaerica. He is is clearly talking about the Earth's energy budget, which is purely determined by radiation (convention only causes differences in the distribution of heat energy within the Earth). Hence Sphaerica is absolutely correct. I guessed that you might be arguing that PDO has an indirect effect on radiation (even though you did not actually say that) as that is the only way in which your position seemed to have any logical consistency (see my previous comment about how to deal with perceived inconcistencies). However, as I said, in order for your hypothesis to be worth considering you need to take the next step and show that PDO is actually linked to outbound IR radiation. You have not done so. Pointing out a paper that mentions PDO and stratospheric temperatures is not evidence, especially as the paper seems to be about the polar stratospheric vortex, which is not the same thing as global stratospheric temperatures or outbound IR radiation. Again your posting style comes across as unhelpfully arrogant; there was nothing non-sensical about spaerica's analogies, and rhetorical dismissal of someones scientific argument does not encourage further discussion. -
Eric the Red at 02:16 AM on 23 July 2011It's Pacific Decadal Oscillation
Dikran, Maybe I did misunderstand you. Looking closer at your comment, that appears to be the case. We seem to agree that ENSO can cause convectional changes. Therefore, what is preventing the additional heat in the atmosphere from radiating out to space? Sphaerica seems to think that energy can only be radiated, and dismisses convection through nonsensical analogies, which is where I perceived your contradiction. Here is just one paper on then ENSO effect on stratospheric temperatures. http://www.atmos.washington.edu/~cig4/tropprecursorsrevisedv3.pdf -
Bob Lacatena at 02:11 AM on 23 July 2011It's Pacific Decadal Oscillation
106, Eric the Red, If you have not already done so, I very, very, very strongly suggest that you go read: Blaiming the Pacific Decadal Oscillation post here on Skeptical Science (from March 5, 2011). It contains a lot of information that you'll find useful, including, most importantly, a (failed) effort by Dr. Roy Spencer to attribute current warming to the PDO. Please read it thoroughly. I also suggest following the links to actually read the source papers, in particular Schneider et Al (2005). -
Bob Lacatena at 02:00 AM on 23 July 2011It's Pacific Decadal Oscillation
106, Eric the Red,I never said anything about a proposal to wait a few decades.
Would you care to clarify exactly how long we should wait to evaluate the impact of a 60 year oscillation, just to make sure that we're not missing anything, and that maybe climate change isn't really happening and it's all just part of the natural ebb and flow of the climate? [Hint: I've been here before with you. It starts with "we don't know" and moves on to "we should wait to be sure" and ends with "oh, a few decades should do it."] After all, we know so little (according to you). So, we're supposedly at the end of the warm phase of the PDO. How long will temperatures need to continue to rise for you to abandon the idea that there is anything of interest (as far as long term, substantive climate impacts) in the PDO? -
dana1981 at 01:45 AM on 23 July 2011Lessons from Past Climate Predictions: William Kellogg
The site is Skeptical Science - we're real skeptics. Although it had a strong physical basis, Kellogg's prediction had some problems which are useful to learn from. Those who don't learn from past mistakes are doomed to repeat them. Easterbook comes to mind. James Wight is going to try and work on a post detailing the various measures of climate sensitivity this weekend.
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