As I've explained, climate is the global average over at least ~20 years. That's a limitation of modern science; raw data simply isn't dense enough, and not enough decadal oscillations can be simulated precisely enough to meaningfully talk about "climate" on a shorter timescale. Trends of 8-9 years are probably under the noise floor, and (as I explain in that link) it's important to remember that just because CO2 is the most significant forcing, that doesn't mean other forcings are completely insignificant.
Because of this limitation, climatologists primarily use hindcasts through proxy records to validate the models, among other techniques. Making a prediction and then waiting 20 years to see if it comes true isn't practical, so few peer-reviewed papers tend to ask "Hey, what did that model 20 years ago predict?" But these analyses are informallyperformed and they seem both honest and generally positive to me. You can verify this yourself by downloading the GCM source codes and global temperature data in the sources listed here. Remember to smooth over at least 20 years, and compare the projected emissions used to the actual values. (Most projections give several "scenarios" where CO2 emissions change differently to account for uncertainty in future human behavior.)
But all that doesn't matter in the context of the point I was making, khayman, which is that there is a lot going on climate-wise that the models do not account for.
Oh, then we agree. I just thought you were implying that the models were missing something demonstrably significant.
Found the talk; it was given by Lenny Smith and even worse/funnier than I recalled:
"Is it conceivable that models run on 2007 computer hardware could provide robust and credible probabilistic information for decision support and user guidance at the ZIP code level for sub-daily meteorological events in 2060? In 2090? Retrospectively, how informative would output from today's models have proven in 2003? or the 1930's? Consultancies in the United Kingdom, including the Met Office, are offering services to 'future-proof' their customers from climate change. How is a US or European based user or policy maker to determine the extent to which exciting new Bayesian methods are relevant here? or when a commercial supplier is vastly overselling the insights of today's climate science?..."
Oh, and I'm going to once again reproduce my own comments on Dumb Scientist. Notice that this is just like when I notified you in advancelong before I posted any of our conversation, and even before most of our very first conversation. (You even replied and didn't object.) Then you complained, saying something to the effect that since I didn't copy all of your posts as well, I shouldn't even be allowed to copy my own comments because they internally quote yours.
But I really want to share that anecdote and other info. So I'll post my comments on Dumb Scientist (as I've always done) right after the end of our last conversation, but this time I'll cite the internal blockquotes as coming from "Someone". Of course, the links will lead here (but no one follows those, right?) so no one will know it's you. Then I'll replace your exact words in the blockquotes in my comments with paraphrased versions that-- no matter how I write them-- will likely provoke you into a blind rage. But either way, I won't label these comments with your pseudonym, and all of your words will be replaced with the shortest, most neutral paraphrasings I can think of. Unless you claim the right to my words, or to the abstract concepts we've discussed, I don't see how you would have reasonable grounds to object to this.
I guess I'll have to come up with some kind of tortuous way around using the words "completely unknown" and "significant" and "destroyed" in my comments, though.
Oh, I also need to reword some of my phrases that imply continuity between "Someone" and "Jane Q. Public".
Hmmm...
This will take quite a bit of time, but I don't want to be accused of being unethical, or have people question my goodwill, integrity, or ability to deal in polite society. It seems a little odd that I'm not allowed to copy the comments I type into Slashdot's comment box straight into the comment box on my own website, but you probably have a truer moral compass than I do, so I'll defer to your wisdom and divert this time and effort away from my dissertation.
Oops. Replace "Compare the surface forcing due to ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant"." with:
Compare the surface forcing due to stratospheric ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant".
Then open the IPCC AR4 WG1, Chapter 2, page 149...
"...Global [stratospheric] ozone amounts decreased between the late 1970s and early 1990s, with the lowest values occurring during 1992 to 1993 (roughly 6% below the 1964 to 1980 average), and slightly increasing values thereafter. Global ozone for the period 2000 to 2003 was approximately 4% below the 1964 to 1980 average values. Whether or not recently observed changes in ozone trends (Newchurch et al., 2003; Weatherhead and Andersen, 2006) are already indicative of recovery of the global ozone layer is not yet clear and requires more detailed attribution of the drivers of the changes (Steinbrecht et al., 2004a (see also comment and reply: Cunnold et al., 2004 and Steinbrecht et al., 2004b); Hadjinicolaou et al., 2005; Krizan and Lastovicka, 2005; Weatherhead and Andersen, 2006)...."
... and re-examine your use of the phrase "completely unknown".
Oh, I forgot an anecdote in that list of mine. I was nursing a beer at a talk on the reliability of GCM predictions at the 2009 AGU Fall Meeting... I don't remember the title or speaker, but I think it was the middle of the week and I vividly remember the sweet, sweet taste of free lager, so it must have been right after "beer o'clock" which at the AGU is mid-afternoonish. Anyway, the guy was showing a website claiming to provide regional climate predictions for annual averages (not ~20 year averages!) of temperature, humidity, precipitation... out to 2030... for specific zip codes. By the end, the room was howling with laughter. The notion that current science is anywhere near this accurate is on par with the idea that the CIA is advanced enough to remotely control our brainwaves unless we're all foiled up.
Until very recently, there was little if any evidence (that was available and analyzed, at any rate) that the troposphere was warming to a degree that matched the greenhouse warming models. Only a few weeks ago did I learn that some relatively recent papers did in fact indicate that the troposphere appeared to be warming in a way that better matched the models.... Your comment about "overlapping sensitivities" means next to nothing in this context.
And just to save you from pointing out that "this context" isn't what was quoted directly above that, I know. The reason I ignored all the sentences that preceded the statement about overlapping sensitivities is that I'm not saying Liu and Weng did shoddy work or that there are problems with their instruments in particular, so there's no need to recite their validation techniques.
What I'm saying is that all of these remote measurements are subject to larger uncertainties than surface data. The reasons I gave are similar to those on page 6 of this report. I'm merely trying to emphasize that the troposphere debate was due to uncertainties in remote measurements, which still remain larger than surface measurement uncertainties.
... here we have yet another instance of a phenomenon that could have significant climate effects, that was completely unknown until now.
Compare the surface forcing due to ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant".
Until very recently, there was little if any evidence (that was available and analyzed, at any rate) that the troposphere was warming to a degree that matched the greenhouse warming models. Only a few weeks ago did I learn that some relatively recent papers did in fact indicate that the troposphere appeared to be warming in a way that better matched the models.... Your comment about "overlapping sensitivities" means next to nothing in this context.
Ironically, the issue you're describing was exacerbated by precisely this overlap problem. Sensors designed to measure the upper troposphere also pick up signals from the lower stratosphere.
Second, the graphs in figure 4 don't "vividly illustrate" low SNL. This is just yet another of your specious dismissals. Your claim of low SNR contradicts what the paper itself says about the statistics (and the information we already have about these instruments). The stated errors in the trends (slopes) are at a 95% confidence level. That's not bad.
I'm not referring to the error bars on the linear trend. I'm referring to the fact that predicting the climate is a boundary value problem; it's really all about measuring the energy imbalance of the Earth. Notice that skeptics like Dr. Pielke advocate using ocean heat content as a diagnostic of climate change rather than surface air temperatures. I agree with him about this point, because the ocean has a vast heat capacity compared to air at the surface. So it's a better place to look for an energy imbalance (in theory).
In contrast, the heat capacity of the stratosphere is even lower than that of air at the surface. In other words, it's a really bad place to look for signals of a global energy imbalance.
And the spikes caused by El Chichon and Pinatubo are just about what one would expect.
Good thing we know what to expect because of GCMs... right?
And it makes little sense to complain about few instruments (actually more than you imply; the data was cross-correlated with other satellites) when those instruments are pretty much the best available, and in some cases the only ones available. Why do you not make the same complaint about CRU's use of only a few bristlecone pines as temperature proxies?
Because there's a difference between remote measurements made by a few dozen sensors over the last ~40 years, and thousands of surface temperature stations backed up with boreholes, ice cores and numerous other proxies extending much further back in time. I'll complain when I see a genuinely peer-reviewed paper make a sweeping claim based only on weak proxy data.
You have argued with every piece of counter-evidence I have seen presented to you.... I find it very interesting that you have consistently made negative comments about credibility of sources, accuracy and SNR or measurements, and so on... only in regard to counter-evidence....
Notall of them. Also, I'm annoyed with the prevalence of the term "tipping point" in the mainstream media, when we don't have any idea where it lies, or whether runaway warming is remotely likely in the foreseeable futu
... However, I still have to make the point regardless of the cause of the temperature fluctuations, standard greenhouse models today still account only for the lower stratosphere to be cooling....
Strictly speaking, that would be another point. Your first point was that "stratospheric warming shows GCMS are fundamentally flawed." After an excruciatingly long conversation, I finally convinced you to read the abstract closer and realize the paper doesn't support your conclusion.
You then repeated a terse version of the same point on someone else... as though our conversation had never taken place. Your second point was "lower stratospheric warming shows GCMs are fundamentally flawed." This time, I simply linked my previous comment to once again suggest a closer look at the abstract.
Now, you've presented a third point which still isn't supported by the paper, considering that the last three words of the abstract aren't qualified by the word "lower".
Of course, I just listed more fundamental reasons why I (and most scientists in the world) think that looking for signals in the stratosphere rather than on the surface is a wild goose chase. Then I listed them again but I may as well have been talking to myself. Ironically, figure 1 in that paper (overlapping sensitivity kernels, few instruments, large instrumentation noise, etc) and figure 4 (huge aerosol forcings and small heat capacity equals low SNR) vividly illustrate several of those reasons.
Oh, also, I replied to your last comment. At first I thought your silence was due to the phrase "no more to say to you" at the end of your last comment, but I'm starting to think that my replies fell off the bottom of your Slashdot comment list. I don't particularly want to prolong that conversation (physics is way more interesting!) or advertise that bickering widely, but letting you know about them in the most low-key fashion possible (in an article that's left the front page) seems like the decent thing to do.
They clearly state in the abstract that the reversals (referring to the "reversing" temperature trends seen in the mid and upper stratosphere) may be due to ozone recovery. They did not state that about the lower stratosphere, which is where they found warming where cooling was expected. I am pretty darned sure I read that correctly. You might want to take another look.
Huh? I already did, ten days ago. Behold: "From long-term ozone measurements at Arosa Switzerland Zanis et al. (2006) found a negative trend in stratospheric ozone before 1996 and a positive trend in lower stratospheric ozone between 1996 and 2004. Miller et al. (2006) have utilized a statistical model (Reinsel et al. 2002) to study the ozone trend by using the ozone data from 12 ozonesonde stations in the midlatitude of the Northern Hemisphere. They also found a negative trend before 1996 and a positive trend since 1996 in the lower stratospheric ozone.""
Hmm... it seemed like you were quoting that paper as though it were somehow evidence against GCMs. In that context, it seemed on topic to point out that not even the authors of the paper agree with this conclusion; they instead attribute the warming to a recovery in stratospheric ozone (along with Switzerland Zanis et al. 2006 and Miller et al. 2006, as mentioned in the paper's discussion.)
But if I got the wrong impression and rudely butted in, I apologize. To be honest, I don't really understand what you're talking about, so I'll bid you good night and not bother you any more.
Climate models for the most part do not conserve energy and/or have unphysical boundary conditions, and all of them are parameterized in unphysical ways. Anyone who isn't sceptical of them is missing something.
Here are links to the source code for many GCMs. Please name the model which doesn't conserve energy. If you're feeling generous, it would also be nice to know how to reproduce this (obviously serious!) problem.
Last year, you said something similar:
But you're not a computational physicist, or you would have noticed the lack of energy conservation in some models (it is added by hand as a correction on each time step) or unphysical boundary conditions in others (ocean surface in particular). If you were a computational physicist you'd know how big a deal these approximations are in long-term integrations of even very simple systems, much less complex ones like GCMs. I was a lot more convinced by the AGW argument before I started looking at the models than I am now. [radtea, July 28 2009, @07:57AM]
I'm baffled by these statements. Energy conservation is a fundamental law of the universe, but floating point calculations are necessarily imprecise. Correcting for roundoff errors that affect energy conservation in every time step seems like good programming practice.
Also, there are other reasons to apply conservation laws "after the fact." Several years ago I studied the gravitational effects of shifting precipitation patterns. The GRACE satellites measure the global gravity field every month, which changes because of heavy rainfall, droughts, etc. Comparing the GRACE monthly gravity field to the gravity field implied by hydrology models like GLDAS revealed interesting discrepencies like a consistent phase lead in the GLDAS model which we hypothesized was due to a flawed river model.
But none of that would have been possible if I hadn't "added in mass conservation by hand as a correction in every time step." You see, GLDAS only provides the mass of water over the land every month. If this total mass is integrated, it's not constant in time. Which just shows that the water is being swapped between the land and the oceans. So I wrote a short script to add a spatially uniform layer of water to the ocean each month that forced the total amount of water on Earth to be constant. (Obviously this was only a first order estimate because I neglected water vapor and oceanic circulation patterns which violate the assumption of spatial uniformity.)
Incidentally, my confidence in GCMs is drawn primarily from their demonstrated skill in completely different validation techniques. I'm not surprised or concerned that tuning parameterizations simplify microphysics, perhaps to the extent of oversimplifying them. As my comments in that linked conversation show, I do consider such imperfect approximations to be good reason not to consider GCMs sophisticated enough to produce regional climate predictions. But their track record with global averages seems impressive.
I'm also not sure what you mean by unphysical boundary conditions at the ocean surface, but I'm eager to learn what you meant by that statement.
Perhaps it would help to show an example where my editing wasn't intended to portray you in a negative light. After you cited an E&E paper to support the claim that sunspot cycle length is responsible for recent warming, I said:
... But I'll make it up to you. Here's an article by Friis-Christensen and K. Lassen, published in Science in 1991. This would have been a legitimate example of a peer-reviewed journal article supporting your claim.
Of course, it's incorrect. You can find out how-- if you're interested-- by following its citations in google scholar to the present. For nonscientists, read the summary here. The moral of this story is that data smoothing is difficult to do in an objective manner, which is something all computational scientists screw up on occasion. Please don't mistake this comment as criticism of Friis-Christensen or K. Lassen-- I've certainly made far bigger mistakes in my own research. The ability to admit a mistake and move on is the mark of a true scientist. [Khayman80, July 09 2009, @09:37PM]
After some more unpleasantness, I later repeated:
... The claim that sunspot cycle length correlates well with Earth's average temperature was made in the mainstream journals in 1991. But it was quickly shown to be a spurious connection based on data smoothing parameters. The fact that "Energy and Environment" didn't catch this when the argument was made again 15 years later just shows that they're not experts in the field.... In fact, that article you're leaning on quotes Friis-Christensen and K. Lassen (1991) several times, without seeming to understand that the reason their conclusions are no longer valid has nothing to do with the data they used, and everything to do with the way they smoothed the data.... [Khayman80, July 10 2009, @09:19AM]
You responded:
... As I stated before, I only found that paper after you asked me to find one, and I was not particularly careful in choosing it; you had asked for a peer-reviewed paper, and I just grabbed the first one that was visible. And indeed, some of its claims do appear to be refuted, particularly in a paper by P. Damon, published in Eos in 2004. However, though you apparently knew this (as, I could guess, did Mr. Landis), neither of you bothered to cite any kind of actual data in an attempt to refute the one paper I provided, per your request.
After you mentioned the data smoothing issue, it took me about 2 minutes to find Damon's paper. If I had been aware of it in advance, I would of course not have offered that paper. But if you really wanted to make a point -- and practice what you preach -- you should have cited your sources. Instead, you left me to look it up... which makes you are guilty of exactly the same faux pas of which you accuse me. In point of fact, Damon's paper itself states, "The graphs [from Friis-Christensen and Lassen] are still widely referred to in the literature,and their misleading character has not yet been generally recognized." Without citing sources, then, how did you expect me to know?
Just FYI, whenever I get a chance I'm going to copy my comments to my blog, which include your statements in blockquotes as above. As per usual, links will be provided to this page. I do this because I like to have a central archive of all my statements on a single page so I can find references using ctrl-F.
Yes, but I'm not using the vanilla level 1-b or level 2 data products. I'm using accelerations that have already had background models like FES2004 and various dealiasing products subtracted. That data was only given to me when I promised not to share it or publish papers on certain topics using it.
Of course, chapters 9 and 11 each mention McIntyre 3 times. Each time, their claim is briefly but not extensively discussed because their conclusions on page 117 include: "The instrumentally measured warming of about 0.6C during the 20th century is also reflected in borehole temperature measurements, the retreat of glaciers, and other observational evidence, and can be simulated with climate models."
As far as I can tell, the largest caveats to emerge from the NAS report are concerns about the uncertainty estimates (especially prior to 1600 CE) and this point on page 115: Even less confidence can be placed in the original conclusions by Mann et al. (1999) that "the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium" because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales.
Second, the two papers you mention (Rutherford 2005 and Wahl and Ammann 2007) are based on CRU data, the Rutherford paper even has Jones and Mann as coauthors.
My point is that those papers can't be affected by the claimed MM PCA "mistake" because they use different methodologies.
There was ample opportunity to cook (deliberately or via unintentional observer bias) the CRU estimates to restore the hockey stick by 2005.
I've already linked the results of independent temperature reconstructions. And last year I said: Each time series in the graph I previously linked is referenced in chapter 6 here. Turn to page 469 and examine Table 6.1 (later, if you get bored, consider checking out column 2 of page 466 which reviews the claims of MM03 and MM05.) Every time series is referenced well enough to be found on google scholar-- for example here's one of them. As you've seen from the graph, they all support the abrupt temperature increase in Mann's graph. (I freely admit that all these authors could be drooling morons, sheeple incapable of independent thought, or evil conspirators... any of these scenarios or a linear combination of them would completely discredit my position.)
Notice how all these reconstructions are consistent. Most interesting is PS2004, which reconstructs past temperatures using a borehole. By measuring the temperature of the ground at various depths, past temperatures can be reconstructed using heat conduction equations.
This isn't based on CRU data at all, yet is consistent with it. That's not too surprising, because there's no evidence that the CRU data has been "cooked" as you imply.
While peer-reviewed papers aren't always correct, their signal to noise ratio is far higher than blogs, so I highly recommend learning science from them rather than the rantings of economists and miners. If you seriously think the overwhelming majority of the scientific community is spectacularly incompetent or involved in an evil conspiracy, then there's very little I can do. After all, that means I'm a drooling idiot or a conspirator too, right? I see no point in a conversation like that. Have a nice day.
Slashdot Mirror
As I've explained, climate is the global average over at least ~20 years. That's a limitation of modern science; raw data simply isn't dense enough, and not enough decadal oscillations can be simulated precisely enough to meaningfully talk about "climate" on a shorter timescale. Trends of 8-9 years are probably under the noise floor, and (as I explain in that link) it's important to remember that just because CO2 is the most significant forcing, that doesn't mean other forcings are completely insignificant.
Because of this limitation, climatologists primarily use hindcasts through proxy records to validate the models, among other techniques. Making a prediction and then waiting 20 years to see if it comes true isn't practical, so few peer-reviewed papers tend to ask "Hey, what did that model 20 years ago predict?" But these analyses are informally performed and they seem both honest and generally positive to me. You can verify this yourself by downloading the GCM source codes and global temperature data in the sources listed here. Remember to smooth over at least 20 years, and compare the projected emissions used to the actual values. (Most projections give several "scenarios" where CO2 emissions change differently to account for uncertainty in future human behavior.)
Oh, then we agree. I just thought you were implying that the models were missing something demonstrably significant.
Found the talk; it was given by Lenny Smith and even worse/funnier than I recalled:
"Is it conceivable that models run on 2007 computer hardware could provide robust and credible probabilistic information for decision support and user guidance at the ZIP code level for sub-daily meteorological events in 2060? In 2090? Retrospectively, how informative would output from today's models have proven in 2003? or the 1930's? Consultancies in the United Kingdom, including the Met Office, are offering services to 'future-proof' their customers from climate change. How is a US or European based user or policy maker to determine the extent to which exciting new Bayesian methods are relevant here? or when a commercial supplier is vastly overselling the insights of today's climate science? ..."
Oh, and I'm going to once again reproduce my own comments on Dumb Scientist. Notice that this is just like when I notified you in advance long before I posted any of our conversation, and even before most of our very first conversation. (You even replied and didn't object.) Then you complained, saying something to the effect that since I didn't copy all of your posts as well, I shouldn't even be allowed to copy my own comments because they internally quote yours.
But I really want to share that anecdote and other info. So I'll post my comments on Dumb Scientist (as I've always done) right after the end of our last conversation, but this time I'll cite the internal blockquotes as coming from "Someone". Of course, the links will lead here (but no one follows those, right?) so no one will know it's you. Then I'll replace your exact words in the blockquotes in my comments with paraphrased versions that-- no matter how I write them-- will likely provoke you into a blind rage. But either way, I won't label these comments with your pseudonym, and all of your words will be replaced with the shortest, most neutral paraphrasings I can think of. Unless you claim the right to my words, or to the abstract concepts we've discussed, I don't see how you would have reasonable grounds to object to this.
I guess I'll have to come up with some kind of tortuous way around using the words "completely unknown" and "significant" and "destroyed" in my comments, though.
Oh, I also need to reword some of my phrases that imply continuity between "Someone" and "Jane Q. Public".
Hmmm...
This will take quite a bit of time, but I don't want to be accused of being unethical, or have people question my goodwill, integrity, or ability to deal in polite society. It seems a little odd that I'm not allowed to copy the comments I type into Slashdot's comment box straight into the comment box on my own website, but you probably have a truer moral compass than I do, so I'll defer to your wisdom and divert this time and effort away from my dissertation.
This conversation continues...
Actually, I should have explicitly said "mocking a website" rather than "showing a website".
Oops. Replace "Compare the surface forcing due to ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant"." with:
Compare the surface forcing due to stratospheric ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant".
Then open the IPCC AR4 WG1, Chapter 2, page 149...
"...Global [stratospheric] ozone amounts decreased between the late 1970s and early 1990s, with the lowest values occurring during 1992 to 1993 (roughly 6% below the 1964 to 1980 average), and slightly increasing values thereafter. Global ozone for the period 2000 to 2003 was approximately 4% below the 1964 to 1980 average values. Whether or not recently observed changes in ozone trends (Newchurch et al., 2003; Weatherhead and Andersen, 2006) are already indicative of recovery of the global ozone layer is not yet clear and requires more detailed attribution of the drivers of the changes (Steinbrecht et al., 2004a (see also comment and reply: Cunnold et al., 2004 and Steinbrecht et al., 2004b); Hadjinicolaou et al., 2005; Krizan and Lastovicka, 2005; Weatherhead and Andersen, 2006). ..."
... and re-examine your use of the phrase "completely unknown".
Sorry, I should have mentioned that page 624 is in chapter 8.
Oh, I forgot an anecdote in that list of mine. I was nursing a beer at a talk on the reliability of GCM predictions at the 2009 AGU Fall Meeting... I don't remember the title or speaker, but I think it was the middle of the week and I vividly remember the sweet, sweet taste of free lager, so it must have been right after "beer o'clock" which at the AGU is mid-afternoonish. Anyway, the guy was showing a website claiming to provide regional climate predictions for annual averages (not ~20 year averages!) of temperature, humidity, precipitation... out to 2030... for specific zip codes. By the end, the room was howling with laughter. The notion that current science is anywhere near this accurate is on par with the idea that the CIA is advanced enough to remotely control our brainwaves unless we're all foiled up.
And just to save you from pointing out that "this context" isn't what was quoted directly above that, I know. The reason I ignored all the sentences that preceded the statement about overlapping sensitivities is that I'm not saying Liu and Weng did shoddy work or that there are problems with their instruments in particular, so there's no need to recite their validation techniques.
What I'm saying is that all of these remote measurements are subject to larger uncertainties than surface data. The reasons I gave are similar to those on page 6 of this report. I'm merely trying to emphasize that the troposphere debate was due to uncertainties in remote measurements, which still remain larger than surface measurement uncertainties.
Compare the surface forcing due to ozone at any reasonable concentration to that of CO2 at today's concentration, and then re-examine your use of the word "significant".
Ironically, the issue you're describing was exacerbated by precisely this overlap problem. Sensors designed to measure the upper troposphere also pick up signals from the lower stratosphere.
I'm not referring to the error bars on the linear trend. I'm referring to the fact that predicting the climate is a boundary value problem; it's really all about measuring the energy imbalance of the Earth. Notice that skeptics like Dr. Pielke advocate using ocean heat content as a diagnostic of climate change rather than surface air temperatures. I agree with him about this point, because the ocean has a vast heat capacity compared to air at the surface. So it's a better place to look for an energy imbalance (in theory).
In contrast, the heat capacity of the stratosphere is even lower than that of air at the surface. In other words, it's a really bad place to look for signals of a global energy imbalance.
Good thing we know what to expect because of GCMs... right?
Because there's a difference between remote measurements made by a few dozen sensors over the last ~40 years, and thousands of surface temperature stations backed up with boreholes, ice cores and numerous other proxies extending much further back in time. I'll complain when I see a genuinely peer-reviewed paper make a sweeping claim based only on weak proxy data.
Not all of them. Also, I'm annoyed with the prevalence of the term "tipping point" in the mainstream media, when we don't have any idea where it lies, or whether runaway warming is remotely likely in the foreseeable futu
Strictly speaking, that would be another point. Your first point was that "stratospheric warming shows GCMS are fundamentally flawed." After an excruciatingly long conversation, I finally convinced you to read the abstract closer and realize the paper doesn't support your conclusion.
You then repeated a terse version of the same point on someone else... as though our conversation had never taken place. Your second point was "lower stratospheric warming shows GCMs are fundamentally flawed." This time, I simply linked my previous comment to once again suggest a closer look at the abstract.
Now, you've presented a third point which still isn't supported by the paper, considering that the last three words of the abstract aren't qualified by the word "lower".
Of course, I just listed more fundamental reasons why I (and most scientists in the world) think that looking for signals in the stratosphere rather than on the surface is a wild goose chase. Then I listed them again but I may as well have been talking to myself. Ironically, figure 1 in that paper (overlapping sensitivity kernels, few instruments, large instrumentation noise, etc) and figure 4 (huge aerosol forcings and small heat capacity equals low SNR) vividly illustrate several of those reasons.
Oh, also, I replied to your last comment. At first I thought your silence was due to the phrase "no more to say to you" at the end of your last comment, but I'm starting to think that my replies fell off the bottom of your Slashdot comment list. I don't particularly want to prolong that conversation (physics is way more interesting!) or advertise that bickering widely, but letting you know about them in the most low-key fashion possible (in an article that's left the front page) seems like the decent thing to do.
Huh? I already did, ten days ago. Behold: "From long-term ozone measurements at Arosa Switzerland Zanis et al. (2006) found a negative trend in stratospheric ozone before 1996 and a positive trend in lower stratospheric ozone between 1996 and 2004. Miller et al. (2006) have utilized a statistical model (Reinsel et al. 2002) to study the ozone trend by using the ozone data from 12 ozonesonde stations in the midlatitude of the Northern Hemisphere. They also found a negative trend before 1996 and a positive trend since 1996 in the lower stratospheric ozone.""
Oops... I meant Zanis et. al 2006, based on work performed in Switzerland. Sorry for any confusion that caused.
Yeah... um... you're not helping. Be quiet and let the adults talk.
I finally got around to posting our conversation, which I mentioned months ago but never got around to. Thanks again for your interesting comments.
Hmm... it seemed like you were quoting that paper as though it were somehow evidence against GCMs. In that context, it seemed on topic to point out that not even the authors of the paper agree with this conclusion; they instead attribute the warming to a recovery in stratospheric ozone (along with Switzerland Zanis et al. 2006 and Miller et al. 2006, as mentioned in the paper's discussion.)
But if I got the wrong impression and rudely butted in, I apologize. To be honest, I don't really understand what you're talking about, so I'll bid you good night and not bother you any more.
Here are links to the source code for many GCMs. Please name the model which doesn't conserve energy. If you're feeling generous, it would also be nice to know how to reproduce this (obviously serious!) problem.
Last year, you said something similar:
I'm baffled by these statements. Energy conservation is a fundamental law of the universe, but floating point calculations are necessarily imprecise. Correcting for roundoff errors that affect energy conservation in every time step seems like good programming practice.
Also, there are other reasons to apply conservation laws "after the fact." Several years ago I studied the gravitational effects of shifting precipitation patterns. The GRACE satellites measure the global gravity field every month, which changes because of heavy rainfall, droughts, etc. Comparing the GRACE monthly gravity field to the gravity field implied by hydrology models like GLDAS revealed interesting discrepencies like a consistent phase lead in the GLDAS model which we hypothesized was due to a flawed river model.
But none of that would have been possible if I hadn't "added in mass conservation by hand as a correction in every time step." You see, GLDAS only provides the mass of water over the land every month. If this total mass is integrated, it's not constant in time. Which just shows that the water is being swapped between the land and the oceans. So I wrote a short script to add a spatially uniform layer of water to the ocean each month that forced the total amount of water on Earth to be constant. (Obviously this was only a first order estimate because I neglected water vapor and oceanic circulation patterns which violate the assumption of spatial uniformity.)
Incidentally, my confidence in GCMs is drawn primarily from their demonstrated skill in completely different validation techniques. I'm not surprised or concerned that tuning parameterizations simplify microphysics, perhaps to the extent of oversimplifying them. As my comments in that linked conversation show, I do consider such imperfect approximations to be good reason not to consider GCMs sophisticated enough to produce regional climate predictions. But their track record with global averages seems impressive.
I'm also not sure what you mean by unphysical boundary conditions at the ocean surface, but I'm eager to learn what you meant by that statement.
Read the abstract closer. They specifically state that "the reversing trend may relate to a possible recovery of stratospheric ozone concentration."
Perhaps it would help to show an example where my editing wasn't intended to portray you in a negative light. After you cited an E&E paper to support the claim that sunspot cycle length is responsible for recent warming, I said:
After some more unpleasantness, I later repeated:
You responded:
I was shocked to see this comment. But address
My comments have been copied here.
Just FYI, whenever I get a chance I'm going to copy my comments to my blog, which include your statements in blockquotes as above. As per usual, links will be provided to this page. I do this because I like to have a central archive of all my statements on a single page so I can find references using ctrl-F.
Yes, but I'm not using the vanilla level 1-b or level 2 data products. I'm using accelerations that have already had background models like FES2004 and various dealiasing products subtracted. That data was only given to me when I promised not to share it or publish papers on certain topics using it.
Of course, chapters 9 and 11 each mention McIntyre 3 times. Each time, their claim is briefly but not extensively discussed because their conclusions on page 117 include: "The instrumentally measured warming of about 0.6C during the 20th century is also reflected in borehole temperature measurements, the retreat of glaciers, and other observational evidence, and can be simulated with climate models."
As far as I can tell, the largest caveats to emerge from the NAS report are concerns about the uncertainty estimates (especially prior to 1600 CE) and this point on page 115: Even less confidence can be placed in the original conclusions by Mann et al. (1999) that "the 1990s are likely the warmest decade, and 1998 the warmest year, in at least a millennium" because the uncertainties inherent in temperature reconstructions for individual years and decades are larger than those for longer time periods, and because not all of the available proxies record temperature information on such short timescales.
My point is that those papers can't be affected by the claimed MM PCA "mistake" because they use different methodologies.
I've already linked the results of independent temperature reconstructions. And last year I said: Each time series in the graph I previously linked is referenced in chapter 6 here. Turn to page 469 and examine Table 6.1 (later, if you get bored, consider checking out column 2 of page 466 which reviews the claims of MM03 and MM05.) Every time series is referenced well enough to be found on google scholar-- for example here's one of them. As you've seen from the graph, they all support the abrupt temperature increase in Mann's graph. (I freely admit that all these authors could be drooling morons, sheeple incapable of independent thought, or evil conspirators... any of these scenarios or a linear combination of them would completely discredit my position.)
Notice how all these reconstructions are consistent. Most interesting is PS2004, which reconstructs past temperatures using a borehole. By measuring the temperature of the ground at various depths, past temperatures can be reconstructed using heat conduction equations.
This isn't based on CRU data at all, yet is consistent with it. That's not too surprising, because there's no evidence that the CRU data has been "cooked" as you imply.
While peer-reviewed papers aren't always correct, their signal to noise ratio is far higher than blogs, so I highly recommend learning science from them rather than the rantings of economists and miners. If you seriously think the overwhelming majority of the scientific community is spectacularly incompetent or involved in an evil conspiracy, then there's very little I can do. After all, that means I'm a drooling idiot or a conspirator too, right? I see no point in a conversation like that. Have a nice day.