Obviously one of the major themes of the M&M articles is the remarkable lack of robustness of MBH98. Bürger and Cubasch, hot off the press at GRL, asks the following question:
whether or not the MBH98 and relative approaches are robust, including the predictor selection issues as argued by McIntyre and McKitrick [2005a], is the subject of the current study.
They conclude:
Without a model error estimate and without techniques to keep it small, it is not clear how these methods can be salvaged to become robust.
They cite both our 2005 articles approvingly.
They introduce the issue as follows:
a number of methodological issues [were] left unsettled in the original version [of MBH98], and which after several critical remarks [cf. McIntyre and McKitrick, 2003] led to the publication of a corrigendum. The discussion, nevertheless, continued [von Storch et al., 2004, McIntyre and McKitrick, 2005a, 2005b; Rutherford et al., 2005; Bürger et al., 2005], indicating that several issues are still unsettled, all related to the problem of reproducibility and robustness. For instance, assertions made by MBH98 and later about certain steps (such as rescaling) being “insensitive” to the method were hard to quantify and thus of little help. Bürger et al. [2005] showed that the method is, on the contrary, highly sensitive to the variation of 5 independent standard criteria (as we call the steps here), resulting in an entire spectrum of possible climate histories.
They conclude as follows:
Any robust, regression-based method of deriving past climatic variations from proxies is therefore inherently trapped by variations seen at the training stage, that is, in the instrumental period. The more one leaves that scale and the farther the estimated regression laws are extrapolated the less robust the method is. The described error growth is particularly critical for parameter-intensive, multi-proxy climate field reconstructions of the MBH98 type. Here, for example, collinearity and overfitting induce considerable error already in the estimation phase. To salvage such methods, two things are required: First, a sound mathematical derivation of the model error and, second, perhaps more sophisticated regularization schemes that can keep this error small. This might help to select the best among the 64, and certainly many more possible variants. In view of the relatively short verifiable period not much room is left.
I wonder how long it will take realclimate to break the bad news.
Bürger, G., and U. Cubasch (2005), Are multiproxy climate reconstructions robust?, Geophys. Res. Lett., 32, L23711, doi:10.1029/2005GL024155. (link)
Climate Audit 
185 Comments
I dunno, your take at least looks of interest – but of course the whole article would be better. I do think your loyal grave dancers (not to mention diggers) will be, as ever, at work right or wrong – dignity on such occasions not being this places strongest suit…
I suspect, as ever, such reports on CA of the death of recons are exaggerrated.
Hope springs eternal…
It’s a curious thing, but when Steve first started on MBH for his own amusement, I doubt that such a frontal assault on the multiproxy study would even have been considered for publication.
wahoo!!!! dance on da grave!!!!
Fascinating to hear Peter Hearnden’s take.
Of course, there was a time when all sorts of arguments were advanced. “It’s only the exxxon-funded sceptics that doubt MBH”. “There is no peer-reviewed criticism of MBH”. “There is a consensus that MBH is right”. “It’s only M&M, and they are canadian…”.
Yet all these arguments seem to be disappearing, like morning dew on a summer day. There is no link to direct-funding by Satan. There is peer-reviewed criticism of MBH. The “consensus” on MBH appears to be evaporating fast. And it ain’t just M&M.
One of these days, PH is going to have to consider that maybe- just possibly- he has to consider the arguments on their merits. And it looks like there are now several extremely robust comments about the merits of MBH in the peer-reviewed literature.
I am just waiting for Dano to chip in with his “they are not really scientists, ‘cos all they are doing is falsifying a hypothesis” line. Sheesh.
yours
per
Yes, I’m sort of glad I didn’t post first, as I could have, on this thread. It’s so much more meaningful to see Peter post his predictable message. Now I agree I want to see the whole article before commenting on it, but we know very well that when Peter does read the whole article he won’t respond on the merits but using whatever talking points the hockeyteam have put out directly or indirectly. Which will probably go something like:
[two or three weeks from now]
Then will follow an off-base article which doesn’t actually address the points in the paper but pretend that B&C were solely attacking MBH98 and that everyone knows that’s old news. Then the thread will continue with the usual suspects posting thank-yous to Mike and so forth for once again showing that the skeptics of AGW are just dead-enders, and where B&C, not to mention M&M or any of the skeptic posters here, will not be allowed to post anything about the actual subject of the paper and of course no post with a link to here will be available.
Re #5
Then it will go strangely quiet as the reply is rejected, although no-one on RC will mention that fact, and the claim will remain on the website and…
Has anyone had this exact same experience before?
One of my wife and my favorite movies. Watched ever year, just like the George C Scott version of A Christmas Carol, which we need to find time for soon.
Ulrich Cubasch, co-author of this paper, was a Lead Author of the Technical Summary of the Working Group I Contribution to the IPCC Third Assessment Report, and a Coordinating Lead Author of Chapter 9 of the same Report (“Projections of Future Climate Change”). He is also a Lead Author of Chapter 1 of the WGI Contribution to the forthcoming Fourth Assessment Report (“Historical Overview of Climate Change Science”).
Re #8
Yes, but is he associated with the skeptics or touched a toilet seat that might previously have been sat on by the friend of the wife of the half-brother of an oil-executive?
You’ve got to be careful about these things.
Ah, Groundhog Day right? But Bill Murray got it right in the end and that is’nt going to happen over at RealClimate. Plus Groundhog Day was a comedy not a tragedy.
Re #10
“This is one time when television fails to capture the true excitement of a large squirrel predicting the weather.”
Re #11.
Very good. How the hell did we all miss that for this long?
Re #12
Well he was hiding his data and methodology. That’s the problem with groundhogs, they only look at their own shadows.
I like the fact that they use the terms ‘collinearity’ and ‘overfitting’. It suggests to me they might be a bit more competent statisticians than the usual suspects. At the moment I can’t see anywhere to read the actual paper to refine that impression.
(If you read a paper and they give you a complicated matrix algebra based description of something and needlessly describe the computational aspects of matrix inversion when all it boils down to is ‘we did an OLS regression’ it is usually a bad sign… I’m mentioning no names)
Somehow the words retro-spanking spring to mind on that comment from TCO.
I should add that Bürger asked me a number of questions about emulating MBH this year and I provided him with scripts and details.
Cubasch was in on a paper in 2004 where they find a MWP with temperatures as warm as today’s average. Climate history and that flatline stuff don’t mix well. Oil and water. Glad to hear of Bürger request. Looks like lots of people are punching their way through the wall. The People’s Republic of Climatology is not so happy a camp.
Re #7 – Dave, if you haven’t already seen it, I would recommend as far superior the 1951 b+w version with Alastair Sim as Scrooge. Sim’s performance (which is magnificent) makes the story come alive in contrast to that of Scott who, with his method-acting approach, falls far short of capturing the magic in the way the Sim does.
It looks like Bürger also presented this paper at a SO&P meeting in November. http://www.cru.uea.ac.uk/cru/projects/soap/pubs/presentations/
There is an other paper on the agenda from Zorita
“On the McIntyre & Mackitrik EOF centering controversy”.
As usual, and it’s frustrating, a password is required to access these.
This paper represents a sea-change. As Ian Castles mentioned, Cubasch was one of the lead authors of IPCC TAR (where Mann ’98 played a “prominent role”) and will be a Lead Author in the Fourth report. He cites M&M approvingly, and comes to the conclusion that Mann’s reconstruction is not robust nor reproducible. Who thinks the 4th IPCC report will feature the “hockey stick”?
The patient (ok sometimes impatient) demonstation by M&M of the many flaws in the Mann reconstructions are having an effect in the climate community. The issue of unarchived records deciding policy costing billions does not take a PhD in statistics to recognize as untenable. In big ways and small, some rationality is appearing.
I hope some readers of this site will read the paper. It’s readily available at http://www.agu.org/pubs/crossref/2005/2005GL024155.shtml for the minor cost of US$ 9.00 if you’re not a member of the AGU. Even individuals without a PhD in climatology can be associate members for less than US$ 200, which gives access to all journal articles, and is a good investment if you have more than a passing interest in climate science (as I would suspect would be the case for most readers of this website).
Taken together with the recent comment by Jan Esper (Esper, J., et al., 2005. Climate: past ranges and future changes. Quaternary Science Reviews, 24, 2164-2166.), who somewhat peevishly cited the Wall St. Journal reporter’s front page article on the M&M story earlier this year rather than cite the M&M scientific papers, saying in part: “So, what would it mean, if the reconstructions indicate a larger (Esper et al., 2002; Pollack and Smerdon, 2004; Moberg et al., 2005) or smaller (Jones et al., 1998; Mann et al., 1999) temperature amplitude? We suggest that the former situation, i.e. enhanced variability during pre-industrial times, would result in a redistribution of weight towards the role on natural factors in forcing temperature changes, thereby relatively devaluing the impact on anthropogenic emissions and affecting future predicted scenarios.”
Congratuations to M&M. This is what (partial) victory looks like.
of course that should be “neither” robust nor reproducible
Just because Cubasch is a lead IPCC author doesn’t mean (1) the hockey stick won’t be featured (or at least presented) and/or (2) hockey-stick support won’t be found in the report (particularly in the Summary for Policymakers, where it’s criticism may not appear). It’s certainly a step in the right direction.
Remember, there are also several other “independent” studies that support MBH98. The more MBH98 is exposed, the more people want to point to the other works for hockey-stick support. And there’s always the edge-of-your-seat wait for the last Wahl and Amman to be published (once they’ve scotch-taped all the pieces that came out of the shredder) in support of MBH98.
The Hockey Stick will be there, but carefully buried under the other spaghetti. The other spaghetti, of course, look nothing like each other and certainly nothing like MBH98, but strangely they all confirm the result of MBH98.
The gravy train will continue to run until the US stops paying for more railroad track.
As the title of the paper indicates, the Burger and Cubasch paper raises questions about ALL multiproxy climate reconstructions, not just MBH. Note in particular the statement “But even when confined to variants better than MBH a remarkable spread remains; the best variant, with an RE of 79% … is, strangely, the variant that most strongly deviates from MBH…”
“
”
Do you mean by this that publically funded climate research should cease, or only that which you disapprove of? What kind of climate research do you, John ‘A’, think should be allowed?
Re: #7 & #19. Yes, the Alastair Sim’s version is by far my favourite. Avoid the colourized version.
Re: #26. Peter, what part of John’s “The Hockey Stick will be there, but carefully buried under the other spaghetti. The other spaghetti, of course, look nothing like each other and certainly nothing like MBH98, but strangely they all confirm the result of MBH98.” do you not read.
John is obviously refering to multiproxy studies. What do you advocate?
Jeff
Peter, that is a slow pitch. Expect John A. will hit it out of the park. Why can’t you see that? Debate requires two pairs of eyes. Good debate four. Do you know why? Each must be able to look at things through their opponents eyes.
Re #27. Jeff, I advocate climate research. I wouldn’t dictate the method used as John A seems to want to do. What would you allow?
Re #28, Ok open yours then! See the bleedin’ ghg, the aerosols, the land use changes! No, (to answer your next post)I didn’t think you would…
Pulling out spoon. Require open data and methods in publically funded research.
No.
Only the climate research which doesn’t require any prior belief in the necessity of its conclusions, the political viewpoints of its sponsors and the moral authority of its authors, which properly states and makes available its data and its full methodology for inspection firstly by competent and fully independent reviewers, then publicly upon submission of the complete report, the authors refraining from any public pronouncement or chinese whispers until the publication of the article, which states in its conclusions a proper assessment of errors, confidences and key assumptions including sensitivity tests and other methodological tests which could potentially falsify or reduce in importance the force of those conclusions, stated in a neutral and reserved language of modest, thoughtful scientists who accept and are aware of their own human biases and frailties.
In other words, climate research that joins the rest of the scientific world in regard to its best practices, skills, ethics and methodologies, and accepts no substitutes or compromises for the sake of political or amoral expediency.
I’m glad you asked.
Re #29. Peter, I support climate research with a particular focus on measuring regional and global climate and trends therein. This will eventually result in more useful models and pre-historical climate reconstructions.
Until these have actually been achieved I would disallow policy aimed at influencing climate.
I must confess though that I am very impressed that you can actually “See the bleedin’ ghg, the aerosols, the land use changes”. Do you have any other superpowers?
Jeff
Re: #21 by Geoff —
Raymond PierreHumbert has a somewhat acerbic new piece on RealClimate today, that attempts to explain why the Esper et al. conclusion is erroneous due to faulty logic. Because it is lengthy, I have to re-read it to see if RPH is actually making sense.
I’ve been approaching the conclusion that any predictions of future climate states, which utilize estimated climate sensitivities based on Holocene paleoclimate reconstructions, will be counter-intuitive. That doesn’t mean it’s a worthless exercise; it means that the system doesn’t necessarily operate the way that my simplistic mind thinks it oughta.
#29 – US taxpayer dollars have no place in climate research. Checking this little document called the Constitution, I can see no authority for our politicians to spend our hard-earned taxpayer dollars on their favorite research projects, or any of the other pork that you usually find in Congressional spending bills. Fund it privately. Who wants Newt Gingrich and Hillary Clinton deciding what areas of climate science deserve funding anyway?
Re: #34 – Let’s take it a little easy here; not try to throw out too much baby with the bathwater. Because climate research could have policy implications, I think it is important to continue to fund research in those areas.
That said, I think the prevailing opinion here is that publicly funded research should have a very high bar in terms of transparency of methods (and data) and reproducibility.
#35 – “Because climate research _could_ have policy implications”
And those policies as well are outside the scope of what we agreed in contract that our politicians should be doing.
RE #35: I’ve certainly never said or implied that climate research is not a worthwhile activity. Quite the opposite. Because it is so important, climate scientists should ensure that their methods and data can be independently analysed and stop acting like prima donnas. It’s too bad that the various learned societies who have recently weighed in on the politics have not also weighted in on this topic.
Re #31, Sorry Peter, just checked John’s bat for cork. This one stands. Anyone got another ball?
Re #36, Nanny, your horse will find few riders here, at least on that trail.
#34 & #36 –
The need for climate research aside (how else are we going to learn how to make the machines that control the weather?), he has a point. There is no Constitutional allowance (at least in the United States) for government funding of this type of research. If there should be a desire for such a thing, then the Constitution allows for amendments to it. That would be the proper course.
Unfortuately, anyone expressing the idea that the US government has no Constitutional authority to fund climate research causes them be labled in all sorts of nasty ways. The opposition, though, stems not from the “results” of the research, but the ideas of what are the proper functions of government. What’s worse, is that some will use this research to then attempt to do more things through the government that the government would have no authority to do.
(but it’s all a moot point because 90% of the US Constitution has been ignored)
It is distressing to me to think that part of my hard-earned money went into funding for MBH98, and continues to partly pay the salary of Michael Mann, and other hockey team members. Public funding of climate research (and other pork spending) is unjust, as the only way I can opt out is to practice tax evasion and risk fines and jail time. Peaceful, voluntary funding is true democracy in action as people can vote with their pocketbook which research deserves funding instead of being forced at the point of a gun to pay for the politicians’ favorite.
#40: Getting further off topic here, but the first paragraph of the section that defines the powers of Congress:
General welfare anyone? Note that I am not saying that the US needs to take action, but it is certainly reasonable to say that “provid[ing] for the … general welfare” includes reasonable attempts to determine the nature of human impact on climate.
#42: James Madison:
For more reading on what Madison thought of this clause, and how it might be applicable to this discussion: Here.
Andy,
I agree and I’m generally a very conservative fellow. US ‘liberals’ have distorted this phrase to mean anything which helps people, which is what we now think of as ‘welfare’. But the general welfare meant, in the terms in use when the Constitution was written, those things which helped everyone, not just a particular special interest, no matter how rich, poor or numerous. We need to be careful about what we have the government doing, but figuring out whether or not humans are affecting the climate in a big way, is definitely one of those things which would fall under the rubric of “promote the general welfare.” Whether or not we’re getting enough bang for our bucks is another question.
Your interpretation of “general welfare” totally invalidates the entire document. Why have a Constitution that is supposed to limit the power of government, and then pull one phrase out and interpret it to mean that the government has virtually unlimited power?
Special attention needs to be paid to the meaning of the word “general” which basically means “for everyone”. In other words, spending that benefits a specific university or researcher over another is not “general”, in the same way that we can all enjoy the benefits of a national defense and/or national system of courts.
Dave,
I’m not so sure I agree that climate science falls under “general welfare” as defined in the Constutition. There is little in the Constitution, or the writings of those who wrote it, that indicate research, even basic research for the “general welfare” is a federal government issue. Stretching it to include it would require stretching it to include all sorts of things (which is exactly what has happened). Again, if we think it’s important enough to do it, why not amend the Constitution to provide for it? Until we do, we’ll debate the issue.
Finally…we now know that you are for dirty water and dirty air and more pollution as you’ve declared yourself a “conservative.” Watch out!
RE #40-42: The government of the United States has been funding scientific research since Thomas Jefferson sent Lewis and Clark to explore the Louisiana Territory in 1803. The purpose of the expedition was to bring back information on the animal and plant life, geography, and the people. It was natural science at its finest. As a founding father, Jefferson had an excellent idea of the limits on the federal government.
The trouble with climate research is that it has been hijacked by a bunch of mediocrities, politicians, and religious fanatics masquerading as scientists, not that the government funds it. Once the field has been fumigated and science re-established it will be just fine. The problem is making that happen. Our host has made a small but significant contribution in that direction.
Re: #38
I’m not actually that good, but Peter has a slow arm and no guile.
Nanny’s understanding of the federal role predates the Republican party. Our current concept is largely due to Lincoln’s struggles to improve himself. He saw that government intervention could greatly ease the task for his fellows and thought it a proper and useful tool. The stand against slavery was one of the party’s legs, this was the other.
#47:
There in lies the problem. It will always end up getting hijacked by one side or the other. Can you imagine the cry from the “warmers” if the current situation was reversed?
No…the problem won’t go away. It might even reverse positions, but the problem will still be there.
Our host has made a significant contribution towards making sure that the science is robust, regardless of the outcome. What’s even better about our host is that he is doing it without anybody elses money. Money is not evil, but the “love of money” is at that root. Government’s giving out money fertilize the root. I’ll also argue that not all are biased because of the money, but for other reasons, too.
Yeah…I think we’re pretty far off topic here, in spite of my best efforts to figure out a way to link it back to the topic.
I’m not an American, but, if I were, I would on the one hand not be a Bush-wing Republican and I would not oppose federal funding for climate research. While I appreciate the kind comments, let’s leave the U.S. Constitution out of this.
(It might be a mistake to think that because someone opposes federal funding of climate science on Constitutional grounds that they are a Bush-wing Republican)
Fair enough…it is a different dicussion than what’s happening here.
Re #37: “I’ve certainly never said or implied that climate research is not a worthwhile activity.”
“Worthwhile activity” is not an appropriate criterion for allocating massive federal spending. The people also have very many “worthwhile activities” on which they could spend their money if it was not taken by the Government. An appropriate justification for Government funding calls for both a need so strong that it trumps all of the people’s alternatives (“worthwhile” being not nearly strong enough) plus that the need can only be filled by the Government.
Climate research does not score well by this standard. If there is some critical need for climate research, it must be that the research could tell us whether there is a realistic risk that human activities will lead to climate catastrophe. But is there any real hope that any amount of funding or research could actually develop data sufficient to separate definitively the theoretical human influence on climate from the background noise? With the changes in world temperatures since the advent of good instrumental data measured in fractions of one degree C, and with known periods of at least slight cooling even as CO2 has increased, and with many reasons to think that there were epochs warmer than the present in the pre-instrumental and pre-human-influence past, isn’t the effort to find human influence on climate through the study of historical data completely hopeless? And then, why exactly are we spending billions of dollars a year on an undertaking which so obviously can not accomplish its stated purpose?
Actually paul I think you have done a fairly good job of keeping it on topic. There are some pretty good points you have made on the importance of keeping government out of science…so long as government is giving out the checks it will have an interest in directing that science to the ends of whom ever happens to be in power at the time.
One thing of note on the constitution thing…the “general welfare” clause need not apply…it takes little imagination for one to note that climate research has military applications. In fact it would not suprise me in the least that some if not most or all the hoskey stick team receive at least some funding from the US DOD or dept of energy.
54 40 or fight!
Bürger and Cubasch: The Emperor has no clothes
Phil Jones has been funded by DOE for about 25 years.
Peter,
If YOU were paying for climate research you would certainly have a right to specify what kind of research was done and who did it. You would also have the right to demand access to all the data and computer code.
As an American taxpayer I do (paritially) pay for this research, so this gives me the right to tell my government that I don’t want to fund certain research if I find it is of poor quality (like Mann’s work). The government does not have to listen to me individually, of course, but if enough people express the same sentiment they had better listen to *us*, or we’ll replace them.
Re #58: For now why don’t you try to get hold of Phil Jones’ station data from DOE (copy to your House of Rep)?
The comments here sure are US-centric. But since folks are talking about the military, what about some Pacific Island nations that could be wiped-out by rising sea levels? The White House doesn’t have authority to declare war by itself (I’m a Canadian so forgive me if I’m wrong in believing that Congress has that right), so choosing to ignore the greenhouse effect might actually be construed as an aggressive act that is not constitutionally permitted. I don’t mean to flame out here; I just think it’s an interesting conundrum.
More seriously, this from #32:
“Until these have actually been achieved I would disallow policy aimed at influencing climate.”
I haven’t read everything on this website so I may be missing it. Does any thread on this website actually refute John Tyndall’s findings in the 1860’s regarding greenhouse gases? Does any thread here explain why adding more greenhouse gases to the atmosphere will not increase the greenhouse effect? I don’t think I’ve seen that elsewhere. Okay, first, if as a ‘warmer’ I was to concede that we know nothing of the global climate more than 100 years ago (I don’t, but let’s just say that I do), that in no way suggests to me that we can’t be affecting climate. If you accept Tyndall and forget about everything else in climatology over the last 100 years, in fact, a policy of ignoring anthropogenic impacts is still a policy that influences climate!
Alright, but now let’s look at the past 100 years. RealClimate (I know you’ll hate me for citing them – my apologies) has links to the latest temperature results in the context of the last century. What do you know? Global average temperatures continue to increase. There is some jig-jaggedness owing to major volcanoes and El Ninos (see the NASA GISS link), but based on temperature estimates independent of bristlecones or anything like that, the expected warming trend is observed.
I don’t want to parrot RC’s position on the Pielke challenge too much, but it seems to me that there is still plenty for policy makers to consider wrt climate change.
I think those are open questions, Steve. You just won’t get the answer by being a crappy statistician who refuses to show his work when challenged.
If it were actually happening because of greenhouse warming (media hype aside) it might actually be an issue. Since it’s not, then you can’t really call it an aggressive act now can you. (AGW Discussion aside, since the Pacific Island nations aren’t threatened by rising sea level it’s not really an issue)
To address the AGW issue. Since the US (And Canada) are a net carbon sink, rather than a contributor http://www.climatechangedebate.org/pdf/FanPaper.pdf it would be difficult to call the US an aggressor wouldn’t it. Instead the US should be looked at as a protector absorbing the carbon emitted by the evil European and Asian empires (heavy sarcasm here), the US is more of a protector is it not.
I’ve not seen anything that even addresses it. I know that Steve and Ross’s work are not about this, rather they are more about examining MBH’s work. Not refuting greenhouse theory (that has kept the Earth at livable temperatures, rather than the freezing cold the absence of greenhouse gasses would bring, wiping out much of the warm blooded life).
Not to my knowledge, I don’t believe it’s open for debate. though the amount of increase, and it’s significance is debated at times.
!!! Just as is a policy that addresses it influences it equally as damagingly. though the effect in both cases is minor as to who cares.
OOOHHHHHH a whopping 0.6 degrees C whhooooooo!!! hold me back we are out of control man, simply out of control. I farted a half hour ago. It raised the temperature in my apartment by 0.3 C.
Yes but why, that is the question.
To the climate audit regulars. I’m drunk on Guinness, Traipaiche and Bruichladdich, a bad combination, so I apologize for the heavy sarcasm in advance. But if the newbie here can’t even review the basics of the site he deserves what he gets.
Hey Latham. Hows about reducing the heat in your house/apartment to 14.5 C, see how warm you think it is then.
re 60:
If you want to read about Tyndall and subsequent Arrhenius you can go here:
http://home.casema.nl/errenwijlens/co2/arrhrev.htm
http://home.casema.nl/errenwijlens/co2/arrhenius1901/index.html
You may join the climate sensitivity debate here:
http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=25003&start=1
#62
Really really impressive proof that you have no idea what you are talking about. The US is not a carbon sink off course. The Fan et al paper has been shown to be haevily biased by 1) the inversion method used and 2) the available CO2 measuring stations. In fact the entire result is based on the use or not of one downstream station east of the US. Look for some more recent literature.
An US citizen is using right now 36 times more CO2 than a Chinese. If the Chineses and only the Chineses are rising their living standards to 1/3 of the US (and that shouldnt take too much time) the CO2 fluxes will double. So far about the US being a protector.
The temperature shift to the last glacial maximum is between 4-6°C globally that means the observed 0.6°C passed within 100 years represents already >10% of this shift in the other direction. 2100 it will be about 50-70% and, nothing else changed we are heading to early Eocene CO2 (1000-2000ppm) and temperature levels. Try that by farting on.
Referneces Epica? Or are we just supposed to take you at your word.
Re #34,
presumably you would apply that to Burger and Cusbach (if they were American)? Ignorance would be your bliss.
Can you eludicae a bit more hans. I see I see squigly lines but I have no refrence to what it is.
(Question: what is your blood alcohol level when you can’t spell “it”)
Re #60: why would you say that I would "hate" you for citing realclimate? I cite them all the time and link to them. You’re too used to their censorship practices and their hatred. No censorship here and no hatred. Cite them all you want.
You unfairly assimilate me with me with deniers. My own specific views pertain to a small range of studies – the multiproxy studies – which were felt by IPCC (and even more so the government of Canada) to be important to establishing that AGW was a serious, rather than a minor, issue. I strongly believe that these studies are worthless for this view. Colin Powell’s aluminum tubes were "proxy" evidence for WMD and had an alternative explanation. Likewise these proxies.
I hope that the other studies relied upon by IPCC are better done. However I can’t do do everything in the world and even keeping up with the multiproxy studies is a big undertaking. I’m also trying to simultaneously upgrade my statistical skills. My concern here is that the due diligence processes of IPCC, in terms of actually checking the studies from the ground up, are non-existent, as are those of the various academic journals and that none of these studies presently being relied on have been verified by anyone independent. Add to this the toxic behavior of climate scientists in respect to archiving data and methods.
Based on my own experience, I do not trust a result merely because it’s been published by a journal and cited prominently by IPCC. If those were sufficient for validity, then MBH would be fine. So they are not sufficient conditions for validity. On the other hand, the use of a study by IPCC is hardly evidence that the study is flawed (quite the opposite). But it is not an adequate level of due diligence.
If I had a big policy job, I would arrange for a truly independent assessment of the major studies – not by the authors themselves or their sometime coauthors or fellow travellers, but by people from another discipline entirely. I would view it as a major undertaking requiring funding of its own, as audits do everywhere else. Please do not confuse my suggestion that due diligence be done, with having a preemptive view on the results of the due diligence.
If I were an IPCC scientist, who wanted to change present Republican policy, I would also move heaven and earth to engage the present administration in such a process. What better way to persuade your opponents? I fail to understand why various learned institutions and climate scientists mau-mau-ed the Barton Committee instead of viewing that as a potential opportunity to engage political opponents, however it arose.
#67 – I would apply it to all publicly funded scientific research. I do not believe it is the role of politicians to decide which areas of scientific research receive funding and which do not.
I look forward to anyone demonstrating empirically, that changes in carbon dioxide and methane CAUSE climate change. In other words, rather than an arm-waving argument that this climate model or that hypothesis state that changes in these gases SHOULD cause climate change, an actual demonstration that they DO cause climate change.
Logically this question should have been answered well before the first climate model was setup, but logic and climate science are estranged at the moment, and are seeing other suitors.
If we take for example, the inexact and misleading greenhouse model as a modelling experiment, it is far from obvious to me that if you take two identical physical greenhouses and give one a fractionally thicker layer of glass, that the greenhouse with the thicker glass will have a measureable and persistent higher temperature than the other.
Steve M:
assuming your at home (Canada) it’s some god awfl early in the morning.
I have trouble trusting morning people. Bu I do trust your work.
this is a conundrum for me.
I’m gong to go sit on the hood of my SUV with my rahter nice single malt an contemplate this.
re 66 and 68
The graph depicts annual emmission growth eg growth2000=emission2000/emission1999
Observed emission data from marland et al
http://cdiac.esd.ornl.gov/trends/emis/tre_glob.htm
Marland, G., T.A. Boden, and R. J. Andres. 2005. Global, Regional, and National CO2 Emissions. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.
SRES emission data from IPCC tar
http://www.grida.no/climate/ipcc_tar/wg1/521.htm
Re #33
Like Jack, I’ve read the posting on RealClimate by Raymond PierreHumbert. I think that once you remove all the rats, mice & exotic numbering systems from it you get the following:
1) Changes in climate forcing over the past 1K years or so have been small.
2) Changes in climate over the past 1K years have been small.
3) If,
by any starkly unbelievable chance,the climate turns out to have been more changeable over the past 1K years, then that means it must be more sensitive than we thought to the known small changes in forcing, so we’re all going to fry.As part of the backup to this proposition he cites a paper co-authored by, inter alia, Gavin Schmitt and Michael Mann which compares computer simulations of the effects of volcanoes and solar irradiation changes with the “known” past temperature record (yes, that’s the one). I think this is what drives propositions 1 & 2 above.
By contrast I believe that Esper et al take the view that if climate was more changeable over the past 1k years, then something else besides CO2 must be having a big effect.
You pays your money…
Re #74, where does RTP say we’re ‘gonna fry’? That comment is oh so typical of the knee jerk mind set of poster to here. Crikey, I only think it’s going to get warmer and that it might, might, become a lot warmer.
Re #71, John, you’re living in a pre Arrhenius time warp matey. Of course, you canny bug*er, you know we don’t have an identical other Earth with which to compare ours with. So, you can parrot your question for ever and claim to be right whether Co2 reaches 500 1000 or whatever ppm. Your question is not ‘provable’ as in John ‘A’ provable. It is provable as in if it walks, talks, quacks and the sums add up. I’d try the real world for once if I were you.
re 74:
1) is the problem of solar irradiance reconstructions, take your pick:
and climate sensitivity of the sun and volcanics
http://www.agu.org/meetings/sm05/sm05-sessions/sm05_SH22B.html
http://www.agu.org/pubs/crossref/2005/2004GL022119.shtml
and comments
http://www.agu.org/pubs/crossref/2005/2005GL023287.shtml
http://www.agu.org/pubs/crossref/2005/2005GL023312.shtml
Re#71
John A does not seem to have any idea what happens in the real world
Clearly he has never been involved in the processes scientific research.
I’m waiting for that real world to actually appear. We have ice core records for hundreds of thousands of years but they don’t show temperature rise following carbon dioxide rise, but the reverse. They don’t show that changes in greenhouse gases are a cause of climate change, but they do show that they are a response.
If it walks, talks, quacks and the sums add up then please show me the mathematical duck prodigy.
Aristotle made the claim that the moon has phases because it “is its nature to have phases”. The sums add up for Aristotle as well – it doesn’t mean that Aristotle’s claim was correct or even meaningful. Maybe he didn’t have a second moon to compare it to.
The point of codeifying physical law is to be able to perform experiments. Thus with Newton’s Laws of Gravitation, I can caclulate how far a javelin would be thrown by Steve Backley if he were on Mars without actually having to organize a space mission to test it
Carbon dioxide has been much higher in the atmosphere for much of the last 600 million years, even during Ice Ages. Why didn’t the sums add up then?
Or, if you want to get much closer to home, a recent ice core study claimed that the current atmospheric concentration of carbon dioxide and methane was much higher than it has been for “at least 650,000 years”.
Q: Why isn’t the Earth’s temperature higher than it has been for “at least 650,000 years”?
I don’t actually expect you to respond to this question with sums, Peter, but I am betting on quacking.
What? Much higher, than ‘a certain date’ you mean? Ok, when?
Besides, you’re also just plain wrong – http://www.realclimate.org/epica_co2_f4.jpeg (and, judging by the delta O now looks pretty darn warm compared with the last 650, 000). I think you’re getting back into that dodgy ’97/3′ mire tbh.
Btw, what’s your opinion of plate tectonics? I can’t see it’s John ‘A’ provable. Ok, there is plenty of evidence (there is with AGW), and a sound theoretical basis, but not John ‘A’ certainty. It’s accepted, there is a consensus. So it’s wrong?
Peter and JOhn, what the hell does your conversation have to do with burger and cubash?
#80 –
Ice cores…I think they mentioned ice cores in there and aren’t ice cores proxies in some way? Therefore, since the topic is how the multiproxy studies appear to be usless (according to Burger & Cubash), and ice cores have something to do with the multi proxy studies, they’re on topic :-}
RE #72: ET Sid, to explain the problem of the strange posting time: I’m quite the reverse of a morning person. I tend to work late rather than early. There was something outside in the middle of the night and our dog started barking. I got up and couldn’t get back to sleep so I went online for a while and then went back to bed. This is a more usual start time for me. I hope that solves your conundrum.
Re #60. Steve Latham,
I understand the mechanism that describes how increasing greenhouse gases in the atmosphere should be result in a net warming trend. The atmosphere should warm which should reduce the heat loss from the surface which should warm the surface. It is a global effect that should have a global impact. I cannot disprove this but I do not see it happening.
Regardless of which global temperature data set you use, the Earth’s surface is warming faster than the Earth’s atmosphere. Is the surface warming the atmosphere? If so then the cause cannot be greenhouse gases.
The Northern Hemisphere is warming faster than the Southern Hemisphere. The Antarctic Ice Sheet is growing. These observations are not consistent with the theory.
In the Northern Hemisphere there is warming but it is not regionally consistent. I have taken the Environment Canada weather data available on the Internet and constructed a temperature trend for Eastern Canada (east of a line running roughly from Alert to Kenora to Windsor). The available temperature data is uncorrected for any potential urban heat island or land use effects. The trend is negative up to 1997. It is positive up to 2001 and then becomes negative again. The theory is not consistent with this observation.
Whatever is going on, it is not consistent with the theory of an enhanced greenhouse effect. Perhaps you can see it happening.
Jeff
Re #83
Jeff, it’s a meteorological basic that most of the sun SW incoming radiation passes straight through the atmosphere and warms the surface ( see http://www.grida.no/climate/ipcc_tar/wg1/041.htm ). The surface warms, that warms the atmosphere (OK, basically). Of course LW radiation from the surface also plays a role and a little bit more of this is being trapped by ghg’s warming the atmosphere.
Re the rest, well, land warms faster than sea – you must know this? Antarctica is climatologically isolated (it’s a very high, flat, plateau). Now, eastern Canada is interesting. Why would you suppose that in the early stage of warming eveywhere should warm at the same rate? If a population of people is getting, on average, taller, does that mean there are no short people, or just less of them?
What’s wrong is that when continental drift was first suggested by Alfred Wegener, the scientific consensus was overwhelmingly hostile and remained so for fifty years.
It means “Hearnden” that if you’re flailing around looking for a good example of a scientific consensus that turned out to be correct, you’ve chosen the wrong example.
btw we’re still waiting for the answer to question 1:
I think we’ll get more evasive quacking imho tbh lol
RE #85
We don’t know that it isn’t. Haven’t you been paying attention. Its not possible to determine past temperatures because the proxies are not reliable.
re 86:
The eemian was defined in the Netherlands when in a groundwater well mediterranean sea shells were found…
There aren’t mediterranian shells in the north sea now.
ref
Click to access 135-146.abstr.pdf
J.H.A. Bosch, P. Cleveringa & T.Meijer, The Eemian stage in the Netherlands: history, character and new research, Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (2/3): 135-145 (2000)
You’re right. After all, before we fry, we’re going to drown under the melting ice caps. Or catch diseases spread by warming. Or die in hurricanes that are produced and/or strengthened by warming. Or suffer any number of other fates because GHG emissions and warming are bad, bad, bad.
Re #82, Steve,
I’ve lived several places where I had to burn my trash. Leave nothing for the animals to get into. It makes for better sleep. Glad you have a dog.
This is a big deal, Bürger & Cubasch’s paper that is. You will be shaking more hands at your next talk for a start :), and looking at a bigger audience. Same goes for your next paper.
RE #87 #88
I can’t access the whole article and as my Dutch is, well non existent, it would not help. However from the abstract.
“Eemian sediments were recognized because of the presence of lusitanian and mediterranean mollusc species.”
This seems to imply that the sediments were dated because of the molluscs, ie there are warm water molluscs so these must be Eemian sediments. This is not evidence of a warm Eemian.
Paul, given that the Dutch site is the type site for the Eemian and had warmwater molluscs, surely it’s fair to say that the Eemian was warm (although the dating of the Eemian could then be questioned as well as correlations elsewhere).
Other evidence for a warm Eemian include fossils of hippos and rhinos in England and Germany. These have been known for more than a century.
If the molluscs are not Eemian, than what date are they?
#82 Phew thats a load off.
Speaking of Dogs, I just got a gift for a frends dog. Smoked Cow bone. I think it’s a Femur or something. about 2 1/2 Feet long, very Fred Flintstone looking.
re 91:
As the paper is in English, the lead author JHA Bosch can send you an offprint if you ask him.
Wow. This ClimateAudit site may be one of the best novels ever, complete with villians and knights, subterfuge, intrigue, comedy, history, tragedy, etc. I suggest it be sent to the publishers!
You forget the court jester…
I have a real problem understanding how some scientists get so wrapped up in AGW. We were in a real deep freeze ice age some 15K years ago, right (I think the “consensus” supports this, eh?). We got out of the deep freeze. Hmmm, I can’t think of any way this could have happened without the process of global warming. Now, it’s doubtful that the cavemen were producing enough CO2 to cause this, so there must have been some natural force at work here. Is it a real stretch of the imagination to think that these natural forces are still going on?
That process is beleived to be related to a well known change in the Earth’s orbit over time. The current posited warming may be different. There is also the issue of disruption from any change. That said, there might be some pleasant aspects of GW. I want alligators and palm trees in Virginia. Citrus fruit? Maybe we can even make the Gulf Stream shutdown and freeze the Frenchies! You know Bismark was right…
RE #99 – I’ve cleared my driveway of snow 4 times in 2 days… A little GW might be a good thing.
In order to shutdown the Gulf Stream you’ll have to stop the Earth rotating. That might be quite an engineering feat to pull off just to spite the French.
Re: 84
I believe what Jeff is refering too is the global warming models that predict that man-made global warming will result in the atmosphere heating up first. The data you and Jeff are refering to disproves these models, I believe.
As far as your point about averages, what you say is true – there will almost always be outliers. We also know that averages are skewed by outliers, which would make the use of an average a poor measure in the first place. Sorry for asking what is perhaps an amateur question, but is this taken into account in the historic average temperature data presented by those who support the man-made global warming theory? And if yes, how are “outliers” decided upon?
I paid for the Burger article. Man, they [***eviscerate] that MBH article. I mean they rip it to shreds. We’re going to be hearing a lot more computer model based AGW stuff and a lot more "MBH being *** up doesn’t matter" because Mann’s paper is DEAD! I mean it’s so dead that the other reconstructions are dead too. *** Wow.
Re #69,
Thanks Steve McIntyre. The comment wasn’t directed toward you. It was directed toward the folks who think that this new paper means that AGW does not exist. That’s not what you say; that’s not what the new paper means. But that is how I interpreted a number of comments that attacked climate research as being a waste (I quoted one of them). I suspect there are many commenters who do want to conclude that AGW is bunk and not worth worrying about. I was trying to tell them that they have a long way to go in convincing an open-minded and reasonable person like me.
P.s. 103 reads better with ***explitives included.
#104 –
Steve L,
Wouldn’t it be the other way? The evidence would need to point towards AGW? We would normally assume that humans don’t impact the climate, therefore the theory that humans impact the climate would need to show evidence that this is true. Even the “warmers” should approach the science from a skeptical point of view. I think much of the climate science, to date, is approached from the wrong perspective. AGW may or may not be bunk. What most, who are labled skeptics, think is that the data is inconclusive, therefore its too early to make significant and expensive policy decisions.
Steve M has shown that MBH, upon which much of the policy decisions have been based, is fatally flawed. We still don’t know anything else about AGW.
And what would convince you?
I don’t know what being open-minded has to do with it frankly. If you are open-minded on the issue then it would take convincing to get you to agree with one side or the other. Since you are firmly on one side from what you’ve said, and it would take a lot of convincing “long way to go” for you to change your mind, how is that being open minded? It means that you have already made up your mind, and on this issue at least you are the opposite of open-minded.
Can I disagree without being called close-minded? I wish I didn’t have to re-iterate but … There is a demonstrated physical reason to expect increased greenhouse gas concentrations to increase greenhouse warming. We also have ~fairly good data indicating warming in the absence of other good reasons to expect it. What has to be shown to convince me? Show me that increased GHGs can’t theoretically increase the greenhouse effect
andor demonstrate that other processes are solely responsible for the Earth’s warming over the time period for which we can agree that the data are satisfactory.But it really isn’t hurting anything yet. We don’t even have gators in the Dismal Swamp yet. And it is damn cold in the winter.
Re #103, TCO,
Started to wonder if that wasn’t the case with #25: Ian Castles clue train.
Steve,
Does Bürger and Cubasch’s work help you figure the error bounds? Probably makes the graph look like a fan picked up off a church floor after a revival.
Paul, Re#107, I think it’s great that the M&M work is having an influence. I think it can only help climate science. Unless climate science is fraudulent in general, though, I don’t think invalidating the multi-proxy studies really has that much to say wrt policy. I sincerely hope that AGW can be disproved and soon. However, I think the balance of evidence is presently in favour of AGW. How you or anyone else wants to balance the unknown costs of reducing emissions with the unknown costs of not doing so is not my concern (at least on this thread), but I am trying to say that the skeptics have to do more than just say “we’re not convinced” (it’s one reason I’m disappointed that nobody can do a good reconstruction). The null hypothesis now is provided by GCM’s. They have to be disproven.
TCO (#111), on a personal level, it seems to be hurting my sockeye fishery and my bull trout. I’m sure others would make much longer lists. I’ll refrain because I’m trying to stay on topic.
Re #110. Earth is not a closed greenhouse, and climate is an open chaotic system. The climate response to a modest increase in atmospheric CO2 is not currently predictable. Reconstructed past climates show pseudo-periodicities of various frequencies, such as the Gleissberg cycle and orbital cycles. There are also local cycles such as ENSO and NAO. These will produce beat frequencies in climate that will look like (possibly sudden) excursions from a prior norm. These excursions need not be due to some new forcing but could be just an accident of the sum of the pseudo-periods. But GCMs are tweaked until the CO2 increase reproduces 20th century temperature changes that, for all anyone knows, might as well be spontaneous swings of the system. To then suppose that the GCMs prove CO2 is responsible for warming is to argue in circles. GCM models are far too crude — by one or two orders of magnitude — in spatial resolution, in terms of energy flows, and with respect to modeling clouds, to predict the effect of a 2-4 W/m^2 of CO2 forcing from first principles. AGW might be happening, but there’s currently no way to know. And if it were happening then, given the natural swings of climate, there’s no way to know whether the current warming is worse or better for the ecosphere than what might be happening in the absence of any putative human-caused warming.
We all owe Steve and Ross a big vote of thanks, if for no other reason, for bringing the whole AGW bandwagon under widening rational scrutiny. Up til their entry, it had got to be all about sin and redemption.
Are GCM’s falsifiable? Who died and made GCMs the null hypothesis for climate science?
I’m sorry but when did I call you close minded. I said you might be close minded on this issue, and I didn’t even say that. I simply refuted that you were open minded on the issue. But let’s be frank, the majority of the people here are close minded on this issue, on both sides. As with most issues this is true.
As to what can show you, unless you have opposing data rather than believe on one side you should be undecided. But to be fair we don’t have that data yet, and it is very difficult to determine, as pat has pointed out, but in the absence of that data I still strongly believe the opposite of you.
I don’t think anyone has argued in recent times that Greenhouse theory is false, quite the contrary. Without it this world would be what it once was. A barren frozen wasteland. approx what 25C cooler than now.
“demonstrate that other processes are solely responsible for the Earth’s warming over the time period for which we can agree that the data are satisfactory.”
As already said that is difficult to do for this present time. However, we can show that natural processes can greatly alter the world’s climate. We know this because of multiple previous Ice ages, as well as warm periods that affected the entire globe. We have ample evidence that this has happened multiple times in the past. It can at least be assumed that natural processes could be responsible for the minor change we’ve seen in climate in recent years.
#113: “The null hypothesis now is provided by GCM’s. They have to be disproven.” Wrong, you have it backwards, that is not how science is done. Models have to be proven true by agreeing with data and making valid predictions. GCM’s are very far from that. Here’s a scorecard, judge for yourself. http://www.warwickhughes.com/hoyt/scorecard.htm
The data in this field are also a problem. This site is devoted to the difficulties in proxy reconstruction of past climate temperature. This compounded by the fact that it’s not even clear that the surface temperature measurements are particularly good. Check the thread on this site http://www.climateaudit.org/?p=438, or the discussion on Roger Pielke Sr.’s site.
#109 – “We also have ~fairly good data indicating warming in the absence of other good reasons to expect it.”
We also have cooling from 1940-1975 in the face of rising CO2 concentrations. No reasonable explanation from the climate alarmists has been provided for this.
This has turned into a pretty wide-ranging thread. Here are a few additional contributions:
Re: #86-88, 91-93 – I have enough trouble keeping up with the Holocene, so haven’t looked much at the Eemian. By coincidence however, I worked for 6 years in Amersfoort in The Netherlands where the Eem river (formerly Emer or Amer) has a ford (voorde in Dutch). The original discoveries of mediterranean mollusc species in the Eem region were described by Harting in 1861. This led to naming of the Eemian as the interglacial prior to the current interglacial (the Holocene).
The article referred to in #88 can be found in an Adobe version from the publisher for free at http://www.njgonline.nl/publish/articles/000085/article.pdf in English, and the author (Prof. Meijer) has put an html version on line in both Dutch and English at http://web.inter.nl.net/users/Meijer.T/tm/paginas/ae-pub-eem_BCM.htm . For the record, I have no opinion about temperatures in Holland in the Eemian, but for sure it’s too cold now.
Re #24, 26, 30-32, 34-37, 40-47, 49-54, 57-60, 67, 70 – The funding of science is an interesting question, and the debate has been raging since the 1500’s (perhaps kept them from being too cold, or is it warm?). The best book on the topic is Terence Kealey’s The Economic Laws of Scientific Research. To be sure, it has probably the most boring title ever (with it’s careful blend of two topics almost guanteed to put most people to sleep, economics and science). However, I personally could not put it down. It mainly deals with the question of the efficacy of government-funded science in terms of economic growth, but the whole historical and philosophical treatment is a masterpiece. Kelley was a PhD microbiologist at Cambridge, but has now moved to be Vice-Chancellor at the University of Buckingham (UK). The book is available at http://www.lfb.com/index.php?deptid=849&parentid=8&stocknumber=EC7673&page=1&itemsperpage=24 (or at Amazon for more than double the price).
Re: BàÆà⻲ger and Cubasch – I hope Steve and Ross are not the only experts in statistics that have been looking at this paper. Can anyone confirm their statistical analysis? Looks pretty solid to me.
Re: Null Hypothesis – Can anyone comment on the new Cohn paper ( Cohn, Timothy A.; Lins, Harry F.
Nature’s style: Naturally trendy
Geophys. Res. Lett., Vol. 32, No. 23, L23402
10.1029/2005GL024476) which begins: “Hydroclimatological records (henceforth “HC”) such as discharge and air temperature are increasingly examined for evidence of a structural shift or trend, defined as an upward or downward tendency in the data over time. There is typically little argument about the magnitude of observed trends whether estimated by eye or statistical methods [Craigmile et al., 2004] (although D. Koutsoyiannis (personal communication, 2005) has expressed doubts about the existence of a rigorous and consistent definition of trend). The statistical significance, or p-value, associated with an observed trend, however, is more difficult to assess because it depends on subjective assumptions about the underlying stochastic process [von Storch and Zwiers, 1999; Woodward and Gray, 1993; Weatherhead et al., 1998].”
It goes on to state “It is therefore surprising that nearly every assessment of trend significance in geophysical variables published during the past few decades has failed to account properly for long-term persistence”.
And concludes “These findings have implications for both science and public policy. For example, with respect to temperature data there is overwhelming evidence that the planet has warmed during the past century. But could this warming be due to natural dynamics? Given what we know about the complexity, long-term persistence, and non-linearity of the climate system, it seems the answer might be yes. Finally, that reported trends are real yet insignificant indicates a worrisome possibility: natural climatic excursions may be much larger than we imagine. So large, perhaps, that they render insignificant the changes, human-induced or otherwise, observed during the past century”. Is this the beginning of the end for overzealous claims for GCMs? The abstract is available at http://www.agu.org/pubs/crossref/2005/2005GL024476.shtml and the full article can be purchased for US$ 9.00 as always).
p.s. – somehow Exxon cleverly arranged for the US National Science Foundation to fund this research. Diabolical!
Click to access 257-268abs.pdf
G. Russell Coope, The climatic significance of coleopteran assemblages
from the Eemian deposits in southern England, Geologie en Mijnbouw / Netherlands Journal of Geosciences 79 (2/3): 257-267 (2000)
********Steve Latham says:
The null hypothesis now is provided by GCM’s.
********
No — exactly the opposite. Computer simulations/models cannot be the basis for a null-hypothesis. The proper, overall null-hypothesis is that human effects are too small to affect the GLOBAL climate.
What is the significance of the death of the Hockey Stick climate reconstruction? There are both scientific and policy implications.
On the scientific side, a gross feature of the data is that the CO2 concentration in the atmosphere over the last thousand or so years displays a hockey stick shape. Hence, a demonstration that temperature displayed a similar hockey stick shape was touted as strong evidence in favor of the CO2-temperature nexus and strong support for the AGW hypothesis. If temperatures did not follow a hockey stick shape over that period, something other than CO2 must be a strong driver of average temperatures. Since the GCMs do not show that (suggesting very weak effects of solar fluctuations etc), this conclusion spells trouble for the theory underlying GCMs. In addition (and despite advertising to the contrary), the GCMs are not built entirely from “first principles”. Features of the models are “parameterized” to fit “the data”. If the models are fit to an incorrect temperature series the parameterizations will be wrong and so also will be the forecasts from the models.
As regards policy, the key significance is that there is now much greater uncertainty about the forecast deleterious climate effects of increased concentration of CO2 in the atmosphere and the “mean estimate” of such effects has shifted toward zero. By contrast, the evidence of positive direct effects on plant productivity of increased CO2 in the atmosphere continues to mount. The evidence covers thousands of controlled experiments and also “natural experiments” such as locations where CO2 naturally seaps into the atmosphere. Increased CO2 in the atmosphere has contributed to increased agricultural productivity in the last hundred years. Continuing increases over coming decades may be essential to allowing the world to feed the likely population in 2050. In short, these two strands of research together have raised the likelihood that further CO2 increases from current levels are beneficial on net. The great uncertainty associated with the possible climate effects implies, however, that it may not be wise to actually subsidize the production of CO2 since the cost of possible negative effects could be large. On the other hand, it surely would not seem wise to tax the production of CO2 either. The sensible course would seem to be to base energy policy on other desideratum right now, but to continue research into both the possible climatic effects and biological benefits of CO2.
If it turns out that the negative effects of CO2 accumulation are likely to outweigh the benefits, there will still be plenty of time to control accumulations in the future — if that is judged less costly than mitigating the stongest negative climatic effects while continuing to accept the biological benefits. Unlike noxious pollutants, the potential problem is one of controlling the stock of CO2 (i.e. its gradual build up) not the immediate flow. This makes future control a better substitute for current control of emissions than is the case for other noxious pollutants. Future control using the same technologies available today will also be less expensive (since people alive then will be richer and a given real cost of control will be a relatively smaller part of total GDP), but in all likelihood further technical progress in energy and sequestration technologies will also allow future control at a vastly reduced cost.
#122
>On the scientific side, a gross feature of the data is that the CO2 concentration >in the atmosphere over the last thousand or so years displays a hockey stick >shape.
Wrong. There is variations of a couple of ppm. Check the Law Dome record. How are these variations agreeing or not agreeing with possible climate histories? Check Gruber/Joos 2003 or so.
>If temperatures did not follow a hockey stick shape over that period, something >other than CO2 must be a strong driver of average temperatures.
1) wrong because that would mean someone argued for example in the IPCC that there are no other forcings than CO2.
2) wrong because that would need a temperature reconstruction that is solid/robust etc enough that demonstrates that there ARE strong variations. Buerger/Cubasch and MM however show at best that there are larger uncertainties than has been claimed until now. Nothing to do with what you need to do such a claim.
>If the models are fit to an incorrect temperature series the parameterizations >will be wrong and so also will be the forecasts from the models.
Show me please one GCM that has been tuned on millenial climate reconstruction. Only one. It’s climate sceptics urban legend.
>Since the GCMs do not show that (suggesting very weak effects of solar >fluctuations etc), this conclusion spells trouble for the theory underlying GCMs.
GCM produce about Mann like variability or more such as the simulation by Storch/Zorita. They do not show variations however that you might have in mind, (with eg 1° warmer than today MWP or so) but are not shown neither by MM (as I said before they havent tried to do a reconstruction, but they were demonstrating uncertainties and methodological problems) nor by someone else. So no trouble for GCM in any case. What you would need is to do a reconstruction (if you like MM proved) that shows that there were temperatures in the last 1000 or 2000 years warmer than lets say the last 20 years.
>the “mean estimate” of such effects has shifted toward zero.
By demonstrating large uncertainties in millenial climate reconstructions the GCM best estimate for climate change has shifted to zero???? What does that mean?
>The evidence covers thousands of controlled experiments and also “natural >experiments” such as locations where CO2 naturally seaps into the atmosphere.
What locations are these? Volcanic active areas? Can you give some citations?
>Increased CO2 in the atmosphere has contributed to increased agricultural >productivity in the last hundred years.
Citations please. For such a statement one needs to compare not artificially fertilized crops (just as you say profiting by higher CO2 levels) with normal production (which ofcourse is fertilized) over the last 100 years.
>The evidence covers thousands of controlled experiments and also “natural >experiments” such as locations where CO2 naturally seaps into the atmosphere.
Thousands of experiments? Could you please specify say 20. The in fact very few studies (such as within the Harvard forest experiment) show very ambiguous results about the benefit vs damage vs neutral impact of high CO2 levels. So anyhow, please give some hints how I can find these thousands of experiments documenting publications.
>The great uncertainty associated with the possible climate effects implies, >however, that it may not be wise to actually subsidize the production of CO2 >since the cost of possible negative effects could be large.
So you are suggesting that because there are studies (which you will send us) that convincingly (on a mathematical proof standard of course , as it is asked for millenial climat reconstructions) demonstrated the benefits of CO2 fertilization that it would be a measure of caution not to stop the about exponential CO2 increase. Your cautionary principle starts from a sort of “natural” increase that shouldnt be touched or influenced. This increase will touch in a while (~100-200 years) levels the Earth hasnt seen since the early Eocene. Do I understand this right?
Re: 122
Peter thanks for your issues summary. I will be sending it on to our State Legislature and Governor. It is time for California’s legislature and Governor to take a second look at this issue, before we squander our economic well being chasing reductions in CO2 without fully understanding the science on which California’s greenhouse gas reduction legislation is based.
Russ
Re: 123
The CO2 Science website maintained by the Drs. Sherwood, Keith and Craig Idso at
http://www.co2science.org/scripts/CO2ScienceB2C/Index.jsp
have summaries and references to numerous studies on CO2 effects on plant growth.
The Idsos seem like goofballs.
Re #126
Why?
Epica wrote:
Hegerl et al [2003] and Crowley [2000] are not GCMs but EBM models, which are also relied upon. These are certainly compared to multiproxy reconstructions – look at my recent re-posting on Hegerl et al [2003]. Crowley [2000] is similar. Are they “tuned” on the multiproxy studies? I’m not in a position to say as I have no information on the details of these studies and have not examined them closely. Nor, to my knowledge, has anyone else.
They certainly look like low-hanging fruit for re-evaluation.
Re #116 (Paul) and my null hypothesis comment:
Your link to the report card was interesting. Don’t you think it would have been better if there was another column showing how some alternative model/hypothesis did in each challenge? When I write that GCM’s are the new null hypothesis, I’m saying that the new, unsurprising starting point is that anthropogenic GHGs have a positive forcing. Want to falsify that (John A)? Build a model that ignores anthropogenic impacts and has significantly more explanatory/predictive power than current GCMs. It should account for troublesome periods like the 40’s to 70’s (Nanny, I believe this is usually explained with reference to aerosols), but if the past temperature records aren’t reliable enough for you then it should predict the future better.
On the most recent Wall St Journal thread Ross McKitrick recalls once being unsatisfied that a bad method of doing things wasn’t replaced with a better one. He suggests, however, that there are cases where a suitable substitute is not possible and that in some of those cases it’s better to have no method at all. I submit to you that wrt GCMs, here is a case where to have things your way you must present a utile alternative. In the case of the multi-proxy millenial reconstructions, throwing up one’s hands and walking away may be the best option. In the case of understanding/describing how climate works, that dog won’t fetch, and a more useful model will get used.
PS. It’s frustrating to be told simultaneously (Nos. 116, 117) that the data used to support AGW aren’t actually very good and that a sub-set of those data disprove AGW. Suggestion for a new thread: “what we
canshould all agree upon.”“it should account for troublesome periods like the 40’s to 70’s (Nanny, I believe this is usually explained with reference to aerosols)”
Only with a hand wave.
High aerosol production areas (like China) over the last 20 years or so show warming, not cooling. With most of the aerosols being produced in the Northern hemisphere, you’d expect to see more cooling there relative to the Southern hemisphere, but that’s not the case. So the explanation seems to fail.
#125
Studies of Idzo type I can do by buying dutch tomatoes. They are grown in greenhouses, they are incredibly big and ther are disgusting. The dutch are rising the CO2 in greenhouses for all different plants and it works. That tells us nothing about plant communities and their common behaviour on conditions thy were a priori evolutionary not prepared for.
#128
That exactly defines an urban legend. You havent ever seen the thing, but it seems possible and sounds interesting. To summarize your mail: There is no GCM tuned on millenial timescale and might be there are EBMs (though also a 3 letter acronym, its a very different thing), but you dont know.
Wbat’s to falsify? In order to falsify a proposition, it’s necessary for the proposition to make reference to empirical result. In this case, the “proposition is that anthropogenic GHGs have a positive forcing” makes no reference to any empirical result that shows that increasing GHGs causes temperature rise. The ice core records don’t show such a cause-and-effect, nor does the instrumental record.
You also make the unfounded assumption that anthopogenic GHGs are the sole source of carbon dioxide enrichment in the atmosphere.
What we have here is a concatenation of assumptions, none of which have been tested, leading to assumptions in climate modelling which cannot be falsified, since they are tuned by non-physical parameters to produce results which cannot be checked without a time machine.
The assumption of GHG-induced warming and aerosol-induced cooling are arm-waving gestures by climate modellers without any empirical data to show that either of them vary in the way described. Not one study, for example, has shown that aerosols in the atmosphere actually has the cooling effect described on the scale of decades.
As someone else has already pointed out, most man-made aerosols are produced in the Northern Hemisphere yet it is the NH that shows practically all of the warming compared to the SH, which has barely warmed at all.
If these climate modellers actually followed the scientific method, then they would call these positive and negative feedbacks “Cause X” and “Cause Y” and wait for empirical investigation as to whether either exist and could be identified. Instead, they go straight for the answer, because frankly, reporting results about Cause X and Cause Y doesn’t generate the sexy headlines of climatic apocalypse on which their research careers and funding depend.
Re #132: as to this particular urban legend, you raised the issue, not me. Is this urban legend actually circulating? Do you have any citations? I’ve consciously stayed away from getting into GCM methodology as it’s a large undertaking and not something that I’m prepared to do at this time. The reason why I mention the EBMs is that these are the things that typically are connected to the multiproxy studies in the literature, rather than GCMs (the ECHO-G model being the exception).
I’m but a simple lawyer, with no particular qualifications in this field, but I’d be obliged if someone would answer a few questions for me, which have been troubling me for some time about this entire “global warming” thing:-
1. As I understand it, the coldest inhabited place in the World is somewhere close to Oymyakon, Siberia (min. 71.2c, 96.2F) and the hottest is Dallol, in Ethiopia, where it exceeds 40c, 104F every day of the Summer. Now, where I live it’s between 8c and 35c in the extremes, so if temperatures are going to get warmer, such that at the extremes it’s between 12c and 39c, what do I care? What should you care? People live in one hell of a lot worse than that and still survive.
2. I’m no scientist, but my reading leads me to believe that about 4% of the Earth’s atmosphere is water vapour, when it’s ready to rain, and that in Death Valley, California it’d be lucky to be 0.5%. Further, I understand that CO2 makes up in the order of 0.4% of the atmosphere. In other words, water vapour makes up 100 times the concentration of CO2 in the atmosphere. Now, something odd is happening here, because [and I said I wasn’t a scientist, but] it appears that the Earth’s natural “greenhouse gas” cycle leads to water vapour levels which fluctuate between 0.5% and 4%, yet I’m supposed to be worried about CO2 doubling, resulting in the equivalent of water vapour going from 0.54% to 4.04% at the absolute extremes. In other words, everywhere will get one one-hundredth of a percent hotter than it has been in the past, if CO2 levels were to double in the next 100 years. [I may be missing a certain subtlety here, but if I am, please don’t tell me that the nuance is the fact that the “average” temperature of the Earth will increase by some piddly amount – if the maximum summer temperature rose by 0.75c to 1.5c, does that mean anything? Quite frankly, it doesn’t make any difference to me whether or not it’s 33c and 90percent humidity, or 34.5c and 91.5percent humidity – it’s still bloody hot! [NB. Feel free to replicate “bloody cold” comments if it’s -50c where you are today and it warms up to -49.5c by the time you’re 100 years of age.]
3. Now, I don’t live somewhere where it’s either real hot, nor real cold most of the time – I live in a place where it’s between about 14c and 30c most of the year. If that changed to 17c to 33c…I don’t think I’d move anywhere. Additionally, it might make Siberia a bit more bearable, while making certain parts of Ethiopia uninhabitable. The point is, on average, it’d probably adjust the balance of “nice” vs. “unpleasant” a bit, but would only adjust the “inhabitable” vs. “uninhabitable” by a small amount [Some equatorial places would “suck” a bit more, while some bitterly cold places might become less arctic]. People live and thrive in cold, as well as heat. Plants and animals do the same. If we actually managed to pump enough CO2 into the atmosphere [at the rate of 100th of the rate of change in water vapour] to make huge swathes of the World tropical, would we make it hot enough to kill every yak and long-haired cow on the planet? As a result of our destruction of such important and ubiquitous food sources, would we run out of sustainance?
4. Is there a single climate author out there who is seriously predicting that our contribution to greenhouse gases is going to turn the planet Earth into any uninhabitable “Hell?” Something akin to what we assume happened with Venus – ie. a runaway greenhouse effect, where concentrations of reflective molecules [rather than being “just a touch” closer to the Sun]caused “very bad things” to happen.
I know that Steve and Ross are fundamentally concerned with questioning the methodology of MBH and others, without introducing the fundamentally divisive issue of whether or not it would matter if the World heated up a couple of degrees [to clarify – whether they agree with MBH, or not, S & R still object to the quality of data and the way they support (or hide) that data].
That’s fine and is an inherently valuable exercise. However, it is also valuable for us to occasionally ask ourselves the question, “Does a bit this way, or that way, really matter?” In Dallol, it’d matter. But then, they’re a bit different to us – they spend their money bringing up their families, as best they can – not paying for thousands of people to come up with computer models of weather scenarios that no-one in the history of mankind has been able to accurately predict 3 days in advance, let alone 100 years!
If I lived in Dallol, a couple of extra degrees would really make my life untenable, so I’d move, even if I ended up a refugee [people don’t melt in deserts, they move to better locales. If we didn’t do this as a species, we would have died out before we evolved.]
However, if I lived in Siberia, I’d be rather pleased that a 0.04 x 2 = 0.08% of the atmospheric change in one particular constituent had marginally increased my level of wintertime comfort.
So, my fundamental point in this post is to point out the absurdity of the warmers’ suggestion that a 1c to 4c [for example] warming would make life as we know it either untenable or even unpleasant. I know people who have houses in warmer/cooler climes, and switch between them depending on the time of year. So, people do obviously adapt.
Let me be clear: Steve and Ross don’t make their arguments for or against AGW – they just say the evidence FOR it is crap [whether or not it is proven, is an entirely different matter.]
I, on the other hand, am saying, “It’s warming? Well, I don’t believe you, but so what if it is? Tell someone living in Eurpoe how bad it’ll be for them.”
Brad – you’re wrong about CO2 concentrations. Its concentration is measured in PARTS PER MILLION, currently standing around 380, I believe. A millionth is 0.000001%. Of the annual production of CO2, somewhere between 4 and 10% (depending on your source)is anthropgenic in origin. How the GCMs claim credible results when having to deal with such miniscule quantities of one particular gas amongst all the other knowns, partly-knowns, vaguely-knowns and downright unknowns is beyond my comprehension – but I, too, am not a climate scientist, therefore not one of the “community” (interesting how they apply that description to themselves) – so what do I know?
Brad, the percentage of CO2 in the atmosphere is around 0.038, a tenth of what you thought (should have put that in the first post) – and before anyone corrects me, yes, a millionth isn’t a % (surfeit of red wine to blame – it’s after dinner here in Moscow).
Re #123 — Here is the law dome 3 record for the last thousand years — it sure looks like a hockey stick graph when I plot it:
Law dome 3 data:
years BP ppm
987 279.4
947 280.3
897 282.4
847 283.8
797 283.9
747 281.7
666 283.4
606 280
606 280.4
547 281.7
528 279.6
494 282.4
466 283.2
446 282.8
423 281.9
404 278.7
389 274.3
346 277.2
314 275.9
301 276.5
273 277.5
246 276.9
244 277.2
233 276.7
216 279.5
199 281.6
197 283.7
168 285.1
148 286.1
102 294.7
94 296.5
88 299
67 305
64 305.2
57 307.9
54 309.2
45 311.4
39 314.1333333
34 315.7
“wrong because that would mean someone argued for example in the IPCC that there are no other forcings than CO2”
Someone has argued (see for example the related post on this site on Hegerl et al) that other forcings cannot explain much variation at all over the last thousand years and that only CO2 (masked where necessary by the mythical unspecified aerosols) can explain the purported temperature hockey stick.
This statement “Show me please one GCM that has been tuned on millennial climate reconstruction” misrepresents what I said. What I actually said was “Features of the models are “parameterized” to fit “the data”. If the models are fit to an incorrect temperature series the parameterizations will be wrong and so also will be the forecasts from the models.”
Why did I say “the “mean estimate” of such effects has shifted toward zero”? The point I was making is that if the longer term temperature series looks less like the hockey stick graph of CO2 the significance of CO2 in explaining that long term temperature record (eg in a regression of temperature against CO2) will decline toward zero. In short, if the two series look less like each other, our “best estimate” of the likely effect of CO2 on temperature declines.
The evidence covers thousands of controlled experiments and also “natural experiments” such as locations where CO2 naturally seeps into the atmosphere.
You ask: “What locations are these? Volcanic active areas? Can you give some citations?”
I have seen scientific papers referring to locations in New Zealand and Italy, but do not have the references at the top of my head. A quick google turned up the following book:
Raschi, A., F. Milglietta, R. Tognetti, and Paul Richard van Gardingen, editors. 1997. Plant responses to elevated CO2: evidence from natural springs
which I have perused in the past — so I knew what to google for.
“Increased CO2 in the atmosphere has contributed to increased agricultural productivity in the last hundred years.”
This is based on the experiments measuring the effects of CO2 increases on the productivity of wheat and rice in particular and then applying those experimental results to the increase in CO2 we have seen over the century. You can find references to scientific papers at the Idso web site that another reader mentioned.
You ask for papers on controlled experiments on the positive effects of CO2 on plant productivity (including not just more biomass production but also disease and drought resistance, resistance to ozone pollution and many diseases and better ability to cope with nutrient deficiencies for example) — again the Idso web site is a great place to start for relevant references.
Your last statement purports to paraphrase what I said and ends “Do I understand this right?” Unfortunately, no you didn’t. I was not talking about any “sort of “natural” increase that shouldn’t be touched or influenced”. I was speaking from entirely different paradigm. Consistent with post #135, my perspective is a cost-benefit one. If the AGW crowd really want to get into the policy issues, the argument they need to make is that the likely costs of CO2 build-up exceed the likely benefits. Furthermore, even if the likely costs exceed the likely benefits, it still does not follow that limiting CO2 emissions is the least cost response. For example, mitigating any harmful effects on weather from increased CO2 in the atmosphere, while accepting the beneficial effects for plant growth (and ecosystem productivity more generally) might be a whole lot less costly than trying to limit emissions — particularly in the short run while we continue to develop better energy technologies.
#129: (Steve) I’m glad that you read the scorecard, it’s very eye opening.
“When I write that GCM’s are the new null hypothesis, I’m saying that the new, unsurprising starting point is that anthropogenic GHGs have a positive forcing.” There’s no doubt about that, the question is whether the signal is discernable among any number of other causes of recent warming. A few possible other causes of warming in no particular order without any discussion of each point. (1) The earth’s climate is a chaotic dynamical system that naturally fluctuates a lot on its own without any need for external forcings. (2) The sun’s activity fluctuates and changes the solar flux reaching earth and its shielding from galactic cosmic rays (3) CO2 fertilization of plants lowering the earth’s albedo (4) human activity, e.g., Coruscant in Star Wars where the entire planetary surface is one city (5) bad data measurements or analysis or both.
“I submit to you that wrt GCMs, here is a case where to have things your way you must present a utile alternative.” The only alternative is to do better science. Until then the calls for massive economic dislocation to avert some hypothesized catastophe based on models that don’t even agree with each other is nonsense.
“It’s frustrating to be told simultaneously (Nos. 116, 117) that the data used to support AGW aren’t actually very good and that a sub-set of those data disprove AGW. Suggestion for a new thread: “what we can should all agree upon.”” We should all agree on the raw data being available to anyone. The most important data set is the ground based weather stations since that data is the source of claims for “unprecedented” warming. Once there are multiple competing analyses then we can get a better understanding of what the climate is really doing. As it is, the satellite data and the balloon data show no particular warming.
John (#133): I’m not sure what you’re saying here. Are you saying that we could have got from 280 to 380 ppm CO2 without anthropogenic sources? I’m going to assume that you don’t mean that. Let’s just talk about whether or not increasing [CO2] in the atmosphere contributes to warming; we can let someone else decide whether burning fossil fuels also increases [CO2] in the atmosphere.
On to Popperian science — you had several opportunities to describe the experiments that you think need to be done (eg #78), but chose not to. You may consider this to be quacking but it’s gonna be difficult to scope up small lab experiments to Earth scales and it’s gonna be difficult to get replicate Earths for larger experiments. That means the experiments are going to be performed in computers — it’s the only way to control for other variables. If you think more small scale stuff needs to be done, then advocate (or do) them and maybe when they are completed you can argue that they refute AGW.
What I’m saying is that the “community” says the GCMs represent their best understanding of how climate works. Many of the commenters here would say GCMs don’t represent how the climate works, and that increased [CO2] won’t increase global temperatures (doesn’t matter if it’s anthropogenic, I suppose). The “community” says the additional forcings from CO2 make the models fit the data better than any model that ignores the additional CO2. That’s good enough for me — it means that the GCMs are better than alternative models and they are the most suitable operational model. They represent the hypothesis that I will adopt until a better hypothesis is demonstrated. That focuses on me, and I’m sorry for the narcissism, but I think I may be representative of a large body of people in that regard.
Skeptics may be right that the “community” is biased (consciously or unconsciously). The “community” built the previous null model (no AGW) and then said it performs worse than theirs. Why let them define the null model? It could be a strawman. Build a family of good models that don’t respond to increased atmospheric CO2. If (not iff, but a big if nonetheless) the real climate system is insensitive to increases in CO2 then these models should perform better than the current GCMs. I know they have a funding advantage, but these new alternative models will have the advantage of not including a huge incorrect CO2 term. The latter would be borne out over time as temperatures change (or don’t). I think that’s as empirical as I think you’re gonna get.
I’m getting repetitive here so I think that’s my last post on the topic. Please consider the idea as generously as possible to try and derive something beneficial from it. I look forward to your rebuttal but moreso to your description of the experiments that need doing.
Re #129, The challenge with GCMs is to recognize what they are and aren’t useful for. My book coauthor, Chris Essex, helped develop the radiation code for the Canadian Climate Model, and has worked on fundamental GCM-related topics for decades. If you GoogleScholar “c essex pageoph” the first entry to come up is a paper of his paper in Pure and Applied Geophysics from 1991. In it he demonstrates how small variations in a couple of parameter values, well within known physical ranges, can give you surface warming or cooling due to increased CO2. That models all yield warming is not an empirical fact, it is a result of the choice of parameterization. That doesn’t mean it’s wrong, it just means that the model results can’t be cited as evidence for the beliefs of the modelers, since the modelers make sure the model acts that way. A similar thing happens in economics modeling. The area I started in, CGE modeling, gives modelers lots of room to choose the outcome. You have to pick functional forms and parameters that make sense, but you also have to get results that “look right”, and if they don’t, you go in and tweak something. My small contribution to the field involved using econometrics to constrain this process, but it’s still a very loose business. Hopefully a modeler ends up with a model that makes sense and results that “look right” and learns something in the process of matching coherent inputs to credible outputs, but to then use the model to make long-term predictions is to walk out onto epistemological thin ice.
In talking about signal detection studies it’s important to remember that the papers analyse model-generated signals. To believe the results you have to presuppose that the model parameters are correct. But what the paper tests are, in effect, hypotheses already embedded in the parameters (e.g. CO2 is a dominant forcing). Such tests can support conclusions about coherence between a prior hypothesis and data, but can’t establish the prior itself.
I feel obliged to point out to Brad H that 20,000 years ago the global average temperature was, what, 6 C colder than now. If so, 2-4 C in global average temp might be seen as quite a significant difference. I’m not sure that I can honestly point that out, however, as I think the point of this thread deals with the uncertainty regarding reconstructions of past temperatures. (If that kind of response interests you, Brad, then I suggest you shorten your post and re-submit at one of the not-so-skeptic websites. That’s probably a better way to expose your ideas to criticism, learn what the warmers are thinking, and see how they justify their stances. In a vice-versa kind of way, that’s what I’m doing here instead of relying on warmers to tell me what skeptics think.)
Re: #140
Before you make a claim like that, first look at the data you’re using. The claim that the amount of carbon dioxide in the atmosphere has risen from 280ppm to 380ppm is from the conjunction of two studies: the Siple curve and the Moana Loa carbon dioxide study from 1958 onwards.
But the Siple curve does not join onto the Moana Loa data without the ad hoc adjustment that it takes 83 years for the bubbles in the ice to close.
Other studies done in the early 80s showed much greater variability than the Siple curve, and measurements done in the 19th century of carbon dioxide concentration are substantially higher than the one calculated in Siple, in fact they’re close to or exceeding the modern value.
It’s perfectly possible for carbon dioxide to rise steeply, without human enrichment. As I’ve mentioned before, for most of the last 600 million years, carbon dioxide levels have been much higher. On the geological timescale, the current level makes the biosphere look starved of carbon dioxide.
So what do we have? A curve that has ad hoc assumptions in it, that has never been replicated, that looks like a hockey stick, that has been artificially grafted with the instrumental record.
This reminds me of something, but I can’t remember what…
It’s not for me to refute AGW. It’s for the proponents to demonstrate that AGW is real and important with reference to empirical data which can be replicated and to theory that can be falsified. AGW is rather like Santa Claus – lots of belief with much better parsimonious explanations for the phenomena of Christmas.
I get bored the number of times that believers in all sorts of woo-woo ideas attempt to reverse the burden of proof.
Groupthink.
That’s not empirical at all. It’s religious faith encoded in Fortran-77. With little googling I can point to models that show that God must exist, that Einstein’s Postulate of the constant speed of light is wrong, that homeopathy works, that the Turin Shroud is the burial cloth of Christ, that we’re going to run out of oil by the year 2000 (oops!), that the Apocalypse is at hand.
I’m going to advocate the most radical solution of all. Switch off all computers that are currently running climate models, and go back to the lab. Design simple tests which can replicate each assumption of climate models.
Build some real greenhouses around the world, and test the hypothesis that very slight changes in carbon dioxide can actually make a measureable difference to the temperature within the greenhouse.
Design an experiment that can show whether an ice core does actually store carbon dioxide in the way assumed in ice core studies. I can think of how to do this, so why can’t somebody with a PhD work it out?
Most of all, design experiments that attempt to FALSIFY assumptions.
There are too many opinions and not enough facts in climate science.
Re: #140:
Steve L., I agree with you that “…the GCMs represent their best understanding of how climate works.” The question is, is that an *adequate* understanding for policy-making purposes. For example, I think we would all agree that even the best 19th-century models of the sun were inadequate because they did not understand/incorporate fusion.
The modellers seem to argue that *all* the relevant physics, forcings, etc, have been correctly incorporated into their models. It’s not clear to me that that is the case when even people like gavin from RealClimate admit that even the sign (much less the magnitude) of cloud effects are not well understood. In addition, one would expect reliable, robust models to produce the various known features of the climate system. It seems that many such features can be individually produced in individual models, but not all in even most models. If the models don’t agree with each other in producing such features, how can we be confident in their other predictions? As I mentioned in a RealClimate post, it seems that at a minimum, there needs to be a clear set of benchmarks for models, perhaps a fairly exhaustive list of major climate system features that should be reproduced by a “gold standard” model, and a list of unrealistic features that should not be reproduced by such a model.
RE#141:
Good point, but I’m not sure how much that matters in the first place when you’re talking about the accuracy of GCMs.
Take a look at this section of a 2001 US gov’t report on climate change in the US using both the Canadian Centre Model and the Hadley Centre Model http://www.usgcrp.gov/usgcrp/Library/nationalassessment/01C.pdf . Both widely-recognized and respected models were based on the same input assumptions. While both models predicted warming across the US, they did have slight disagreements as to which areas warmed the most. Precipitation was another story, as the disagreements between wetter vs drier regions appear pretty strong. The combination of temperature change with precipitation change for predicting changes in soil moisture predictions…forget about it.
Same input data, same climate theory behind the models, similar warming predictions in the US…vastly different predictions of consequences both in the US and globally.
Even outside of parameter values, look at how drastic the results change as model versions change. As stated on p550 of the link above, caption for Figure 13: “The HadCM3 results are shown here to point out that different generations of the same basic model can yield results that are as different as results of different models.”
RE #129:
It seems to me, from examples such as the one described above, that the conglomerate of GCMs pretty much predict any possible scenario, so I’m not sure what alternatives are left. Other than generally all “predicting” warming with increased GHG levels (which, after all, is what they are basically programmed to do in the first place), you have your pick of what kind of climate change effects you’ll see based on what model you look at. If you want your region to be the same in 2050 or 2100 as today, you can find a model that will tell you it will be so. I you want to see flooding, there’s a model that says it will be there. If you want drought, there’s a model that says you’ll see it. Or, if you’re like TCO and want to see gators in Virginia, there probably is a model that would support that possibility. And if there isn’t the result you want to see, just wait for the next generation of models, because it could show up there.
Concerning forcings etc, and discussing modeling from a separate Point of view.
I would like to draw attention to two graphs. In the interest of warmers not accepting any source other than something like the IPCC I will stick to the IPCC.
Graph one, temperature record from 1860-2000
http://www.grida.no/climate/ipcc_tar/wg1/fig2-5.htm
What we note, but has been played with a bit, is the warming starting about 1900 to approx, the mid 1940’s We then see some cooling until the mid to late 70′, with the recurrence of warming up to 2000.
As has been pointed out the C02 record shows a steadily increasing concentration throughout the 20th century, with 1945-1975 being a large increase, during a time of relative cooling. Something the skeptics point to as a confounding factor. If we have a direct cause and effect, why the diversion.
Well instead of focusing just on CO2, let’s look somewhere else for a moment.
Graph of solar output from about 1700 to 2000 (Dark black line at top)
http://www.grida.no/climate/ipcc_tar/wg1/fig6-5.htm
Now while we do not see a direct correlation to all temperature records, we see a much closer correlation from solar output to global temperature than we do comparing the CO2 record. The trends seem to be in the right place within an order of magnitude. When we see solar output increasing we see global temperature increasing. When we see solar output decreasing we see global temperature decreasing.
Is it at least a possibility that we might want to spend say 1% of the time we spend examining CO2 forcing looking at solar forcings. I’m no statistician, so I can’t give a good mathematical comparison. But just from rough visuals I seem to see matching trends.
But since the consensus is solar output is steady and CO2 is the only culprit worth examining…
#138
>Here is the law dome 3 record for the last thousand years “¢’¬? it sure looks like a >hockey stick graph when I plot it
And even more sure it has the couple of ppm variation during the time of LIA I mentioned. The robustness of this result was dicussed but lets take it as it is for the moment then it give you an idea of the importance of a possible globle LIA. On the relatively short time scale of the LIA small variations of CO2 put independent limits to temperature variations (because we know how much CO2 gases out of the ocean at say 1°C cooler temperatures and so on. The CO2 record in such an analysis is used as an global tracer for temperatures. It’s a completely independent confirmation for moderate millenial variability. See the paper I mentioned in my first text:
S. Gerber, F. Joos, P. P. BràÆà⻧ger, T. F. Stocker, M. E. Mann, S. Sitch, and M. Scholze. Constraining temperature variations over the last millennium by comparing simulated and observed atmospheric CO2. Climate Dynamics , 20,
281-299, doi: 10.1007/s00382-002-0270-8, 2003. PDF File
>Someone has argued (see for example the related post on this site on Hegerl et >al) that other forcings cannot explain much variation at all over the last >thousand years and that only CO2 (masked where necessary by the mythical >unspecified aerosols) can explain the purported temperature hockey stick.
Solar and volcanic forcing of course is needed to explain climate variability. That is stressed in all papers to that issue I know. Only the last about 100 years slowly grow out of what can still be explained by natural forcing. For the rest everything is in best order. Please check the time scale.
>What I actually said was “Features of the models are “parameterized” to fit “the >data”.
???? We call that tuning. Anyhow please tell me one GCM of which features are parameterized to fit millenial temperature reconstructions. These models were made for understanding ENSO cycles or storm activities or whatsoever. I doubt that the majority of GCM modellers know of MBH or other reconstruction or that they care too much. They are working on different time scales. Tuning of cloud parameters is done to get modern precipitation fields about right but certainly not to get the mean global temperature of 1567 right. Take my word for it.
>The point I was making is that if the longer term temperature series looks less >like the hockey stick graph of CO2 the significance of CO2 in explaining that >long term temperature record (eg in a regression of temperature against CO2) >will decline toward zero. In short, if the two series look less like each other, our >”best estimate” of the likely effect of CO2 on temperature declines.
At least as long as you agree that different types of forcings can be made comparable by their energy input (so e.g. a certain solar variation makes like 1W/m2 and a certain CO2 variation makes also a forcing of 1W/m2) than a stronger varying millenium means a higher climate sensitivity (since CO2 forcing was comparably small over the last 1000 years, see above) in terms of K/W/m2 or there was stronger and unobserved solar/volcanic/whatsoever forcing.
In both cases it does not tell you that CO2 effect declines, rather the contrary.
>This is based on the experiments measuring the effects of CO2 increases on >the productivity of wheat and rice in particular and then applying those >experimental results to the increase in CO2 we have seen over the century. You >can find references to scientific papers at the Idso web site that another reader >mentioned.
Ah, ok. So I was right there are no studies showing any positive effect of CO2 on agricultural production over the last 100 years. There are greenhouse studies and these studies were applied on the rest of the natural or agricultural world.
As I said the benefits of CO2 on the macro scale is very disputed. At least nobody responsible would praise atmospheric CO2 augmentations within 200 year to a level that existed like 40 Million years ago because he/she trusts so much in these results.
>If the AGW crowd really want to get into the policy issues,
No I dont.
Re: #147
You may want to read this paper before assuming that: http://www.scielo.br/scielo.php?pid=S0103-84782005000300041&script=sci_arttext&tlng=en
John,
Because they run a shell organization and give themselves inflated titles. Because they don’t do much in peer-reviewed literature.
Re #149,
Are you talking the Idsos? Where do you get that they haven’t done much in peer-reviewed literature? And where do you get that their titles are inflated? Any organization needs to have a president, say. Director or CEO or whatever other titles an organization might choose to use isn’t inflated as long as the person given the title also does what the title implies. Surely you don’t get impressed by titles, do you? We can start calling you the Principle Researcher In Elucidating Steve’s Talks (PRIEST) for this blog, if you like.
I could do that. And I’d be a dork if I did that. And what have the Idso’s done lately in mainstream science journals?
Re: # 136,137
Thanks for pointing that out, Steve H. I had actually mis-read the page I was taking that from – it said 0.04%, which I transcribed as 0.4% [same excuse as you – late at night, one too many reds].
Re: #142
Steve Latham, thanks for taking the time to respond to my post. I do take your point that, while we might argue about exactly how much colder it was in previous glacial periods, we know it was quite a bit colder (6 C wouldn’t surprise me at all). To be fair to myself, I was talking about it being warmer, rather than cooler. I firmly believe that cooler would be worse than warmer, if it were sufficient to cause widespread glaciation. Conversely, warmer would be bad if it resulted in truly widespread desertification. However, if the warming was merely enough to turn Greenland green, again, it wouldn’t concern me. I was trying, somewhat clumsily, to get across my concerns that many warmers seem to consider any and all ongoing warming to be ominous.
Finally, I take your point about asking the warmers, rather than the skeptics – I might just do that (and make my argument, having re-read last night’s post today, in a slightly less rambling manner).
For now, I’ll return to lurking and let those more expert than me take back the soapbox.
#135
There are some questions on probable GW impact I want to try to answer.
ad 1
Humans are in fact adapted to very different climate zones, much more different than predicted climate change. Human societies adapt to such varying conditions in a fantastic way, so why worry about a couple of degrees more. Well in fact people adapted at all times, and quite often failed at the end. History is written by the survivors but there are a number of ancient societies that became victim of natural climate variability. This “just a little too much variability” often was comparably small (something like 10-20% less precip or say 1° cooler sometimes ). Please have a look in the beautiful look of Jared Diamond, “Collapse”. With a world population soon between 9-10 billions and the increasing energy demands of not just the occidental fraction we are approaching a point of becoming very vulnerable.
ad 2) Water vapour is no active player in the greenhouse in the following sense: it is adapting in a couple of day to the boundary conditions set. What you need for a persistent greenhouse are greenhouse gases with long resident times and good mixing in the atmosphere such as CO2.
>Quite frankly, it doesn’t make any difference to me whether or not it’s 33c and >90percent humidity, or 34.5c and 91.5percent humidity – it’s still bloody hot!
You must look at crops and water availability to get an idea of possible impacts. A sweaty day is not enough. Ask water managers in California what it would mean to LA for example something like 2° warmer winters (no snow left in the Sierras) combined with say 10% less annual precip.
ad 3
>Additionally, it might make Siberia a bit more bearable, while making certain >parts of Ethiopia uninhabitable. The point is, on average, it’d probably adjust >the balance of “nice” vs. “unpleasant” a bit, but would only adjust the >”inhabitable” vs. “uninhabitable” by a small amount [Some equatorial places >would “suck” a bit more, while some bitterly cold places might become less >arctic].
Even if this would be a reasonable forecast (what we lose in the tropics we gain at high latitudes) do you know what you suggest to societies? Besides the vast majority of worlds population is living between 30N and S.
ad 4)
>Additionally, it might make Siberia a bit more bearable, while making certain >parts of Ethiopia uninhabitable. The point is, on average, it’d probably adjust >the balance of “nice” vs. “unpleasant” a bit, but would only adjust the >”inhabitable” vs. “uninhabitable” by a small amount [Some equatorial places >would “suck” a bit more, while some bitterly cold places might become less >arctic].
Runaway greenhouse is impossible since they are no real unlimited CO2 resources that could be mobilized. Sometime Methan clathrates in the ocean are however mentioned as a potential greenhouse gas bomb. I dont think it’s very probable.
#143
And Law Dome. The ice age/gas age difference is very well understood physics, mixing and separation of gases in the firn are even measured in situ (Battle and Bender).
These measurements are probably from Greenland ice (could you please check) which is too warm for CO2 analysis. It has been shown that chemical post depositional processes are responsible for that.
That is correct. The more or less unevitable about 600ppm level we will reach in a couple of decades prevailed about 20 Million years ago, a scenario without any reductions in fossil fuel burning could easily trespass the 1000ppm. These signals will partly left for thousands of years in the atmosphere (they will be taken out of the atmosphere with the time scale of the ocean’s sediment cycle). Your argument is of course a very strong argument for the importance of the greenhouse effect since it was also most of the time in the last 600 Million years considerably warmer. For details look into: Royer/Berner/Montanez/Tabor/Beerling GSA 2004 with impressive correlations between CO2 and T estimates over the last 600 Million years.
John A: I’ve put in blockquotes to aid comprehension
re 147:
This assumes that all forcings are known and we can neglect tidal effects, which have strong effects on ocean mixing (eg Keeling & Whorf)
http://www.pnas.org/cgi/content/full/94/16/8321
http://www.pnas.org/cgi/content/full/97/8/3814
The use of CO2 as thermometer to constrain the MWP was also applied by me
http://home.casema.nl/errenwijlens/co2/thermom.html
# 153
please could you specify a bit more.To start with I dont understand why do you need in such a computation population factors and such. We have the atmospheric CO2 from the ice, so we can test biogeochemical models how much makes 1°,2° and so on cooling (or warming) to the atmsopheric CO2. The approach sets some strong and independent limits to past temperature variations assuming of course over the last thousand years there was no major reorganisation of ocean transport.
re 156:
I assume you mean re 155?
Population is an excellent (99% correlating) proxy for antropogenic CO2 (Idso).
Correcting Law dome using this proxy yields natural co2 variation.
As CO2 in a first order linearly follows temperature (Vostok), you can use the corrected law dome as a CO2 thermometer.
#153, #154:
epica,
Your posting style makes it very difficult to follow your points (at least for me). It would be better when quoting statements for your response to use the blockquote tags, or something similar.
Re #154. What is the source for the reference to “The more or less inevitable about 600ppm level we will reach in a couple of decades”? None of the IPCC projections for 2030, two-and-a-half decades away, are as much as half way between the present CO2 concentrations and 600 ppm: see the relevant Table from Appendix II of Climate Change 2001: The Scientific Basis at http://www.grida.no/climate/ipcc_tar/wg1/531.htm .
Re # 158. Paul, I agree with you.
Epica – it is really difficult to follow you sometimes.
# 156
Thank you for the explanation. I think there are several points not correct in such an approach.
1) Vostok temperature is not global temperature. In particular there is a strong called polar amplification (Masson et al,JGR,2005) of temperatures. Estimates of global mean LGM temperatures were between 4 to 6 colder than today.
2) Temperature is just one factor affecting CO2 and CO2 one factor controlling temperatures. The Vostok record consists of many feedbacks otherwise the observed modern 80ppm CO2 rise would results into a 5°C temperature rise according to your linear relation.
3) Population correlations only can give you anthropogenic CO2 fluxes. Concentration is a quite different business.
4) I really think the approach of Gerber/Joos is the correct one. CO2 variations were very small over the last 1000 years, one could assume (to be on the safe side) that they were double of what is actually measured and try to reconsile this with different temperature scenarios. The results is not necessarily a hockeystick but it sets real limits to strong T variations.
#159
yes I meant the IPCC scenarios. I should have better said: “600 ppm will be reached within this century with very high probability”. In fact several scenarios reach already the 1000 within this 21th century but lets stick to the most probable ones. With “inevitably” a political judgement slipped into my text. Sorry.
re 161
Like so many others you are confusing cause and effect
the response of CO2 to temperature is approximately linear 10 ppm/K
the response of temperature to CO2 is climate sensitivity which is the logarithmic arrhenius law, which parameters are under heavy debate.
http://home.casema.nl/errenwijlens/co2/howmuch.htm
In #154:
Thanks, and I suggest the same for #123, #147, and #153.
From number 71 by John A.
I look forward to anyone demonstrating empirically, that changes in carbon dioxide and methane CAUSE climate change. In other words, rather than an arm-waving argument that this climate model or that hypothesis state that changes in these gases SHOULD cause climate change, an actual demonstration that they DO cause climate change.
I’m not sure if this is what you’re seeking, but it seems relevant:
Ocean Burps and Climate Change
Paleocene-Eocene Thermal Maximum
Quoting from the latter:
“Tracking the ratio of carbon isotopes in marine calcium carbonate sediments, Kennett and Stott found a sharp decrease in the amount of heavy carbon in 55-million-year-old marine fossils, a decline that caused the relative ratio of 13C to 12C to plunge. A gas with very low amounts of heavy 13C must have literally flooded the atmosphere. In 1995, Gerry Dickens, University of Michigan, argued that only methane gas had enough light carbon to produce the early Eocene plunge. He proposed that a belch of methane escaped from ice in seafloor sediments as the Earth warmed during the latest Paleocene. The methane escaped from submarine clathrates, ice crystals that trap methane hydrate, a form of methane ‘ice’ that forms in cold bottom water under great pressures and is widely distributed and plentiful in sediments on the outer edges of continental margins. Methane has a global warming potential (GWP) of 21, meaning it is estimated to be 21 times as effective as carbon dioxide as a greenhouse gas. The massive sublimation and release of sedimentary methane hydrates into the ocean-atmosphere reservoir upset the global carbon cycle and led to runaway global warming.”
Does that do it for you?
Re: #165
No it doesn’t do it for me. For one thing the LPTM and the Eocene hyperthermal are five million years apart. For another the record is too coarse to be able to ascertain whether warming caused the methane belch (if that’s what it was) or methane belching caused the warming.
What caused the belch is a mystery. If a super-Tunguska like cometary fragment were to hit an oceanic basin like the modern Pacific, it would cause a massive shockwave extending right down to the sea bed, the shockwave then passing horizontally to disrupt methane hydrates at the continental margins. But as well as moving the methane, and causing a megatsunami, the consequences would be to vaporize a large amount of water all at once. The water vapor would then condense into clouds trapping the heat, and preventing rain in some places from reaching the ground. Now THAT might cause a big disruption in the biosphere, especially on land.
I’m speculating. I could of course, create a climate model and harden utter speculation into scientific fact.
#166
really, I said this in a post before, it is not possible to produce a lasting climate shift by water vapour alone which has a residence time of a couple of days only. It does not work. Otherwise you are right there are a number of speculations possible, but for producing a warming methane is of course a serious candidate. There were already GCM experiments, see the interesting
Schmidt, G.A., and D.T. Shindell 2003. Atmospheric composition, radiative forcing, and climate change as a consequence of a massive methane release from gas hydrates. Paleoceanography 18, no. 1, 1004, doi:10.1029/2002PA000757.
Re: #167
Just because you made a claim based on zero empirical evidence before I had posted my speculation, does not make anything you said to be suddenly raised to scientific fact.
Nor does quoting a climate modelling simulation of what Gavin Schmidt speculates about raise that model to the status of a single data point in the real Universe.
Neither water nor methane would however explain why the Eocene hyperthermal is around 5 million years after the LPTM but I’d expect the climate modelling community to have a parameter than includes it.
You may not be able to tell the difference between Schmidt and Shindell but that doesn’t mean the rest of us can’t.
Get over yourself. Really.
Re #168. I’ll be honest, it’s quite a good pun is that (though, it being you, you can sense the underlying contempt for your betters…).
#168
You dont mean that there is zero empirical evidence for a residence time of a couple of days for water in the atmosphere, dont you? But then you might mean that, even if the residence time of water is short, it could change climate for hundred of years? Is this your statement? In this case it is obviously impossible to keep a vapour driven greenhouse effect alive for such a long time. Before even the smallest bit of the ocean heats up all the water is longtime rained out.
You wrote that “trapping the heat prevents precipitation from reaching the soil”. What does that mean? It’s so hot that everythings evaporates?
To your idea with a fraction of a comet. Arent usually associated comet impacts with rapid cooling events (killing the Dinosaurs and such)? How is it possible that sometimes it cools/sometimes it warms? Any ideas?
I never worked on the LPTM and similar questions but it’s an interesting subject. I just looked a bit in the web and couldnt find the literature for the 5 Millions years gap. If you please could give me some citations.
Your last remarks I dont understand, I even couldnt find “get over yourself” in my dictionary.Sorry.
re #170
Imagine an atmosphere with earth’s oceans and a temperature above freezing and no GHGs. Water vapor would start to evaporate and being a good GHG would start warming the surface via backradiation from a warmed atmosphere. If we assume for a moment that there was no condensation then the atmosphere would continue to heat until the surface/oceans warmed enough to radiate the insolation directly through IR windows. This would presumably/possibly be a much higher temperature than that we presently have, even with CO2 in it. (The tables for relative humidity assume saturation at some %H2O and thus condensation) Indeed we’d likely have a run-away situation such as we have at venus as essentially all the IR at the surface will be trapped by water vapor, and though the top of the atmosphere would be quite efficient at radiating IR that wouldn’t help the parboiled surface, especially since it would have very little of the gross insolation reflected directly back into space.
If we now turn on condensation, clouds will reflect a good bit of the insolation and the equilibrium temperature will be reduced. Also, a lot of the rain will fall in areas (essentially all of these will be land areas) where the ambient temperature will be below freezing and form ice and snow which will likewise reflect insolation and reduce average temperatures even more. Would this lead to an ice-ball earth? Probably, depending on how much land is near the poles to begin with.
Finally let’s turn on CO2. This would fill in some of the IR holes in the atmosphere and lead to a generally warmer earth, but it would also allow more clouds to form, though higher in the atmosphere if necessary. Still, since we see from the earlier scenarios that condensation of H2O is necessary to prevent run-away GHG heating, this is nothing that the water cycle isn’t prepared to deal with. So any immediate positive feedback from increased surface heating will be offset by increased cloud-cover. The only exception would be if the cloud-cooling negative feedback mechanism were essentially saturated and a minor increase in surface warming sent it over the edge. But that’s essentially disproven by the possibility of an iceball earth.
So we’d expect an intermediate equilibrium, and increased CO2 will introduce a minor modulation but nothing to worry about on a geological time-scale. It’d be nice to know exactly what the ultimate change would be with say a 10x increase in CO2 but probably less than the more extreme models give us for 2100 for a doubling or less. (We know the affect of doubling CO2 from whatever level gives a linear temperature increase so 10x is somewhere near 4 times that value.)
#163
Your webside explaining your application of the CO2 thermometer is completely incomprehensible to me. Sorry.
I try further to understand what you did.
1) The Idso link at the beginning does not work for me.
2) Why using population factors to reconstruct a 1000 year CO2 record? Is this to separate CO2 which might be influenced by man from what is natural?
3) You cite the Law Dome CO2 record on the web side. However your “natural” CO2 values fall to 265ppm in the 18th century in your figure, 10ppm lower than lowest Law Dome values. Is this the correction of Law Dome values? That is in the 17th century there is a > 10ppm correction of the record due to human activities? Since everything seems to be pretty linear what you do could you please give me the formulas.
Most of this is somehow guessed by me and I need mainly confirmation. Your text/webside is very badly organized and does not allow normal reading. Anyhow I am looking forward to an answer.
Re: #169 It’s nice to know that a West Country farmer can spot these linguistic subtleties, otherwise they would be missed by his intellectual inferiors (ie everybody else who doesn’t believe what he believes)
Re: #170
epika and the wonders of climate modelling
Yep. Zero empirical evidence for your claim. What you’ve actually quoted is the parameterization given for water vapor in the climate models that don’t model the climate. It’s an average and its deliberately kept short in order to justify the extraordinary magnification of trace gases like carbon dioxide in climate modelling. You may not have noticed but cyclones last more than a couple of days, and they consist entirely of water vapor.
Yet again a climate modeller quotes a parameterization and states it to be empirical fact. No. It. Ain’t.
Nope, I mean that hypothetically if a cometary fragment were to hit an ocean, it would dump a large amount of water vapor into the atmosphere which would be very hot, and wouldn’t condense into clouds before it had gone once around the earth. That perhaps would then cause a real greenhouse warming, which would prevent the water vapor hitting the ground before evaporating for perhaps between a week and a month, the temperature rising because of increased heat capacity on the same principle of physics on why the temperature rises in a sauna when you throw water on the hot coals.
Then you’d get a megamonsoon in large parts of the globe and large numbers of land-dwelling creatures would die.
As I say, all hypothetical. I demonstrate nothing by guessing.
It depends how much dust it throws into the atmosphere. The Chicxulub event was an asteroid that hit a shallow ocean. My hypothetical comet fragment would hit a deep ocean.
Now we come to the crunch: can epika read a graph?
Look at the Schmidt and Shindell citation posted further up this thread. Why is there a 5 million year gap between the LPTM and the Eocene hyperthermal events on the graph?
If its the one that most climate modellers use then you won’t find “modesty” in there either.
Regarding #166: No it doesn’t do it for me. For one thing the LPTM and the Eocene hyperthermal are five million years apart. For another the record is too coarse to be able to ascertain whether warming caused the methane belch (if that’s what it was) or methane belching caused the warming.
Why are the LPTM (I prefer PETM) and the Eocene hyperthermal supposed to be related? I don’t see any reference a possible or hypothesized linkage.
Regarding causation: the third paragraph of the actual paper Schmidt and Shindell 2003 paper provides context:
“Recently reported research using single specimen isotopic analyses of foraminifera at ODP 690 has indicated that the changes in both carbon and oxygen isotopes were earlier and faster at the surface than at intermediate or deeper depths [Zachos et al., 2001]. Thus, at least at this location, the anomalous warmth and carbon isotope excursion appear to be synchronous and likely occurred first in the atmosphere. This is consistent with CH4 emissions directly into the atmosphere and some degree of consequential global warming.”
As for what caused the initial methane release, this is a possibility:
Speijer, R.P. & Wagner, T. (2002): Sea-level changes and black shales associated with the late Paleocene thermal maximum (LPTM); organic-geochemical and micropaleontologic evidence from the southern Tethyan margin (Egypt-Israel). In: Koeberl, C. & MacLeod, K.G. (Eds): Catastrophic Events & Mass Extinctions: Impacts and Beyond, GSA Special Paper 356, 533-549.
Abstract: Organic geochemistry and microfossil contents of six sections spanning the late
Paleocene thermal maximum are investigated. The sections are arranged along a depth transect (~50–600 m) across an epicontinental basin covering Egypt and Israel. This study is aimed at unraveling paleoceanographic changes associated with the late Paleocene thermal maximum. In three sections (~200–600 m paleodepth), black shales, consisting of dark brown laminated marls with as much as 2.7% total organic carbon (TOC), mark the late Paleocene thermal maximum. The black shales of the deeper sites correlate with pink to gray fissile marls in the shallowest section. In the two remaining sections, this stratigraphic interval is missing. A relative sea-level fall (~30 m) immediately preceded the late Paleocene thermal maximum, during which sea-level rose again by ~20 m. This rise may have been eustatically controlled, possibly through a combination of thermal expansion of the oceanic water column and melting of unknown sources of high-altitude or polar ice caps in response to global warming. During the late Paleocene thermal maximum, the upwelling of low-oxygen intermediate Tethyan water into the epicontinental basin led to enhanced biological productivity and anoxia at the seafloor. Before and after the late Paleocene thermal maximum, upwelling and biological productivity were less intense, and seafloor dysoxia was restricted to neritic parts of the basin. The presence of similar TOC-rich beds in extensive areas in southern Asia indicates that the Tethyan continental margins may have acted as significant carbon sinks during the late Paleocene thermal maximum.
Now you may ask: what caused that ~30m lowering of sea level?
I can’t answer that one. What I can say is that the extraordinarily elevated levels of methane during the PETM are almost certainly the primary cause of the extraordinarily high temperatures of the PETM — unless you’ve got another smoking gun in the closet.
I spent some time at AGU at some of the posters on the Cretaceous and Eocene, attended by some pretty important scientists. The tropical ocean temperatures were estimated to be in the 38-40 deg C range (!). One author (Bice) said that in the Cretaceous, rather than thinking in terms of anoxic intervals, it should be construed as predominantly anoxic with oxic intervals. I didn’t notice particular attention on the so-called PETM in the specialist posters, but was pretty tired and not paying close attention to this issue.
Bürger and Cubasch 05 still not acknowledged at RC. I thought Professor Engelbeen was finally acknowledging the paper (http://realclimate.org/index.php?p=229 #46) — but the “Cubasch” search on RC pointed to a Kaspar and Cubasch paper (http://www.uni-mainz.de/FB/Geo/Geologie/sedi/Deklim/kaspar.pdf), and also an earlier thread on Professor Connolley’s (STOAT) blog with Mr. Hearndon. OTOH, this is a weakly promising sign for my offering that he (WC) would spearhead the B&C’05 spin at RC.
Correction: STOAT also talking about Kaspar & Cubasch (not B&C) — never mind.
Dear Professor McCAll, Ferdinand Engelbeen is not a professor 🙂
When we have so much evidence of extreme climate variability in the past, and such potentially (probably proven, in many cases) powerful forcings from the sun, orbital changes, comets, etc., why should I (a semi-informed member of the public who gets to help pay for all this) be concerned about a relatively small change in GHGs and temperatures? How can anybody who understands even the fundamental questions discussed here keep a straight face, while proposing to spend billions of $ to MINIMALLY decrease emissions, when there is so much uncertainity? Maybe we should start shooting people and wildlife, too, since they exhale vast amounts of CO2.
I’d bet the farm that it’s all about natural forces, folks.
Re: 178
Thx. A mistake, not an attempt at humor or sarcasm (likewise that formal address for me).
RE: #175 — I quick-searched the 2005 AGU abstracts. Only three titles pertained to the PETM.
Until contradicted by obvious refutation, I’ll continue to think it has been well-demonstrated that a big increase in atmospheric methane at the PETM caused a major increase in global temperature at the PETM, which appears to meet John A’s request:
I look forward to anyone demonstrating empirically, that changes in carbon dioxide and methane CAUSE climate change. In other words, rather than an arm-waving argument that this climate model or that hypothesis state that changes in these gases SHOULD cause climate change, an actual demonstration that they DO cause climate change.
(whether he wants to admit it or not).
JohnA,
What demonstration would be acceptible to you? Would you also like a proof that having the sun go nova would kill us all (by us making the sun go nova and then seeing if we die?)
re #181
I’ve no idea where you get the idea that its “about me admitting something”. It’s about proof that effect follows cause.
For instance this:
…does not establish cause and effect. As I pointed out, Schmidt and Shindell’s diagram has the LPTM and the Eocene thermal maximum to be five million years apart. That’s a reeeeaaaallllyyyy long residence time for methane. The UV will have broken down the methane long before then.
Moreover the sparse data shows that the levels of methane at the thermal maximum were lower than at the LPTM, huh? What were Schmidt and Shindell supposed to be showing?
Now there’s a puzzle. Why does the sea level fall by 30 meters? I can only think of a glaciation event that could cause such a fall, something that would cover a continent and weigh it down causing the land to fall but the sea level to fall even further. Then the ice melts off causing the sea to rise relative to the land.
But what causes the warming? Perhaps if there’s a glaciated landbridge that rises up and blocks a cold ocean current from the poles, leaving a large warm shallow equatorial ocean (like the Tethys) to evaporate vigorously? Wouldn’t that cause a rise in temperatures with all that evaporation? (A global sauna effect)
If there’s a link between methane and high temperatures then the LPTM/Eocence Thermal Maximum doesn’t establish it.
This may be what you’re looking for:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11001051&itool=pubmed_Abstract
The onset of the Palaeocene/Eocene thermal maximum (about 55 Myr ago) was marked by global surface temperatures warming by 5-7 degrees C over approximately 30,000 yr (ref. 1), probably because of enhanced mantle outgassing and the pulsed release of approximately 1,500 gigatonnes of methane carbon from decomposing gas-hydrate reservoirs. The aftermath of this rapid, intense and global warming event may be the best example in the geological record of the response of the Earth to high atmospheric carbon dioxide concentrations and high temperatures. This response has been suggested to include an intensified flux of organic carbon from the ocean surface to the deep ocean and its subsequent burial through biogeochemical feedback mechanisms. Here we present firm evidence for this view from two ocean drilling cores, which record the largest accumulation rates of biogenic barium–indicative of export palaeoproductivity–at times of maximum global temperatures and peak excursion values of delta13C….
To John A.
Sorry for the short reply; the holidays call. I’ll continue with this next week. My main problem with what you’re asking/posting is that the PETM and the Eocene Hyperthermal are not postulated to be related (unless you’re looking at a reference I’m not aware of). The Schmidt and Shindell paper and “Science Brief” are only about the methane cause of the PETM. The PETM lasted less than 100,000 years, according to them. So it’s well-separated in time from the Eocene Hyperthermal.
This reference may also be of interest, but I don’t have time to track it down until next week:
Lourens, L., A. Sluijs, D. Kroon, J. C. Zachos, E. Thomas, U. Roehl, J. Bowles, I. Raffi, 2005. Astronomical modulation of late Palaeocene to early Eocene hyperthermal events. Nature , v. 435, p. 1038-1041.
I will note that the cause of a geologically quick ~30m (99 feet) fall in sea level is worthy of consideration. I.e., I would sure like to know what caused that. The chain-of-events is that the fall and chance in bottom pressure allows a profound change in the equilibrium of the seafloor methane clathrates, allowing rapid degassing.
Happy Holidays!
Re: #184
dear hank
I have little to no knowledge about the subject area you are discussing. As I understand it, you are citing that abstract as evidence of the proposition that GHGs cause temperature change. Let me see if I can highlight the relevant words of the abstract that make clear its evidential value in proving that case:
it would appear that the scientists you are quoting are not prepared to commit themselves to a clear and categorical statement that the warming was caused by methane. I wonder why ?
yours
per