Roy Spencer has taken Craig Loehle’s 2000 year temperature reconstruction to 1995 and added the HadCRUT3 to 2007. Obviously, the proxy temperature reconstructions during the Medieval Warm Period would have larger error bars than the current (instrumental) temperatures, so one shouldn’t put too much emphasis on small differences between the current peak and the MWP peaks.
Roy Spencer also looked at what the HadCRUT3 trace would look like if temperatures now remained constant for another 15 years (until 2022)…in that case, the temperature trace almost reaches the +0.6 deg C line (just barely
exceeding the warmest MWP peak).
We can clearly see that the coldest part of the Little Ice Age was unprecedented in the past 2000 years, and the subsequent recovery to the Modern Warm Period.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Now Paul right back at you on this – should he have done this?
Has this reconstruction been properly peer reviewed, published in a quality journal (and that’s not the journal of desperates who can’t get published elsewhere), and most importantly of course has McIntyre been over every inch with a fine tooth comb and said it is OK?
That’s “It’s OK” not an essay.
Why are there no error bars on the graph?
AND oh dear looks like a divergence problem at the end of the graph?? Let’s look at every wiggle now.
This is a really crappy way to science – by blog – Loehle and McIntyre should have done the work, got it peer reviewed and published, then spruiked.
This “trial by blog” stuff is subterfuge
for gaining a priori tacit acceptance by the community.
You guys can’t have this debate both ways after all the high moralising.
Frankly I don’t know who you could believe on this stuff anymore – anyone objective left out there?
Why should I believe this graph and how much ?
Would it be 90% Mott – ROTFL.
The paper has been properly peer reviewed, unlike the ‘hockey stick.’ That isn’t to say it can’t be criticised, like all proxy data. It represents a valuable contribution to the debate that natural variability deniers don’t want.
Steve McIntyre is on the case:
To my knowledge, Loehle’s network is the first network to be constructed using series in which every proxy as input to the network has already been calibrated to temperature in a peer reviewed article. This is pretty amazing when you think about it. It’s actually breathtaking. Every prior network has included some, if not a majority, of uncalibrated proxies.
Here’s the distinction: proxy results from an original author sometimes come as temperature reconstructions or more often in native units, such as dO18, tree ring chronology units, pct G Bulloides etc. Ocean sediments are proportionally a greater part of the Loehle network than predecessor networks and here Stott and others calculate estimated SST in deg C often from Mg-Ca ratios, sometimes using other methods and it is these SST estimates that Loehle uses. By contrast, a Graybill tree ring chronology (for example) comes in dimensionless units and some ice core and coral studies are denominated by their original authors only in dO18 units. The distinction is not necessarily between ocean sediments and tree rings. Sometimes tree rings are used to make a temperature reconstruction (e.g. Tornetrask), but many important tree ring chronologies (and derivatives such as Mann’s PC1) have never been reduced to a temperature reconstruction. This can be important: there’s a reason why you’ve never seen a temperature reconstruction from Mann’s PC1 by itself – it would be too cold throughout its history, a point made long ago in MM2005 (EE), but insufficiently noted. In some networks, uncalibrated proxies were not necessarily even temperature proxies. MBH98 included instrumental precipitation series as “temperature” proxies, presuming that there would be some covariance somewhere with something.
I’ve done a mental survey of all the canonical predecessor networks (MBH, Jones et al 1998, Crowley and Lowery 2000, Briffa 2000, Briffa et al 2001, Esper et al 2002, Mann and Jones 2003, Moberg et al 2005, Rutherford et al 2005, Hegerl et al 2006, D’Arrigo et al 2006, Juckes et al 2007) and assure you that each one of them had a number of series that were in native currency, so to speak, i.e. in dO18 units, tree ring chronology units, etc. The only predecessor network that even had a high proportion of calibrated reconstructions was the low-freq portion of Moberg (which heavily overlaps the Loehle network.)
This selection criterion had an interesting knock-on effect for Loehle’s methodology, which accordingly seemed far too simplistic for JEG. In a CPS approach, popular with Team authors, the series will be standardized to a unit standard deviation, averaged and then re-scaled so that the standard deviation matches the standard deviation in the calibration period. (This latter can be expressed as a constrained regression.) Because the series are already in deg C, Loehle did not carry out either of the two re-scaling steps. Although JEG went ballistic about this, is there anything wrong with what Loehle did, given his network?
In practical terms, I doubt that the difference between the two methods amounts to a hill of beans. My guess is that the “topography” of Loehle’s reconstruction using CPS will be virtually identical to the series already calculated. Simply as a matter of prudence, I see no harm in doing a CPS calculation using Loehle’s network – the calculation is trivial – and that the calculation should be done to show the lack of difference simply because such CPS calculations are lingua franca in the trade. But I doubt that it will make a material difference to the result.
JEG vehemently criticized Loehle on this point and, in a way, it’s more interesting to try to understand exactly what underpins JEG’s vehemence. JEG:
This is a very different situation from usual multiproxy studies which use sophisticated methods to ensure that a proxy’s weight in the final result reflects its ability to record some variance in the temperature field (whether local or not). While there is merit in exploring a bare bones approach (arithmetic mean), it then becomes indispensable to demonstrate that each proxy is : a) a temperature proxy (not a salinity one…). b) a good one at that.
… Once again, such care would not be required when a climate-field-reconstruction or “composite-plus-scale” approach is employed, as the proxy’s ability to record temperature is implicit in the calibration therein. Since the author effectively treats the proxies are perfect thermometers (which is conceptually acceptable as long as it is explicitly justified), the lack of this discussion is unforgivable, and in my book, constitutes grounds for rejection any day of the week.
Or elsewhere JEG here :
either you care about LOCAL temperatures and you use something known as a Composite Plus Scale approach. Or you only care about the ability of a proxy series to record *some* climate information via teleconnections : that is the heart of climate-field reconstruction techniques, like MBH98 or the more sophisticated RegEM-based versions. … In either case you explicitly account for how proxies describe variance in the mean temperature ; either by regressing them against the mean, or against local temperature (and then average them), or against a subset of principal components that describe the large-scale features of the temperature field, then use that to reconstruct this linear subspace of the T field and then average it globally (the Mannian approach).
I think that JEG has got things backward here and that Loehle is actually on stronger ground than the Team on this particular issue.
The calibration of individual proxies to temperature and the demonstration of their validity is a critical issue in this area. Indeed, one of the persistent themes of this blog is precisely this: the failure by the Team to demonstrate the validity of key proxies like Graybill bristlecones or Arabian Sea G Bulloides. Because the Team has relied to a considerable extent on proxies that have not been individually calibrated in peer reviewed literature, the demonstration of the validity of any uncalibrated proxies should, in my opinion, be an item in the presentation of a multiproxy reconstruction; I think that it’s reasonable not to require this demonstration if the calibration has already been done in peer reviewed literature.
Emile-Geay argues that this demonstration of validity is unnecessary in Team articles because the “proxy’s ability to record temperature is implicit in the calibration”. This is simply untrue and completely neglects the pitfalls of spurious correlation and spurious covariance, pitfalls that can easily become worse in a data mining operation. I doubt that many MBH readers realized the degree to which they were relying on calibrations that had never been individually peer reviewed, and the degree to which the reconstruction relied on calibrations generated in a home made algorithm remote from scrutiny by peer reviewers. This problem extends to Mann et al 2007, where once again the same uncalibrated series are being calibrated in an algorithm whose workings are poorly understood, with the individual calibrations being remote from scrutiny by peer reviewers.
In contrast to the Team’s reliance on home-made calibrations remote from scrutiny by peer reviewers, Loehle relied exclusively on prior calibrations done in the sunlight of peer reviewed articles where the calibration could be individually scrutinized. JEG views this as a defect. I disagree – it’s an advantage.
Take a closer look at the proxies:
http://www.climateaudit.org/?p=2393
What software does Luke use to contact him the instant that a global warming post is made on this site?
So what’s the error bounds and why is there a divergence problem at the 20th century end?
Paul – all the proxies look quite different, the temperature scales seem different, should any weighting be used, the combination graph looks as noisy as anything.
So you really need to know the implication of leaving any of the proxy series out – what does it do to the reconstruction. So what’s done in cross validation in this area.
Not saying I’m not interested – just asking. My personal feeling that I got to some time ago was that how well would we ever know what the temperature was with any great precision given the noisy data involved and disparate series.
The Loehle reconstruction is being scrutinised over at climate audit.
As for divergence, don’t ask the IPCC:
http://www.climateaudit.org/?p=1626#more-1626
“My personal feeling that I got to some time ago was that how well would we ever know what the temperature was with any great precision given the noisy data involved and disparate series.”
I agree, but the hockey stick is a gross misrepresentation.
Paul – “We can clearly see that the coldest part of the Little Ice Age was unprecedented in the past 2000 years, and the subsequent recovery to the Modern Warm Period.”
Yes you can see the recovery from the LIA then temperatures were pretty constant for 200 years until 1900 when CO2 and land use changes kicked in and really started the temperature moving again.
First of all HADCRUT3 are global average temperatures and is from an instrumental record with much smaller error. The proxy data is mainly northern hemisphere so you do not know if the LIA and the MWP are nothing more than regional events.
BTW if HADCRUT3 goes to 2007 why does the graph stop at 2000? Current warming is +0.6° which places it equal to what is shown on this graph as the peak of the MWP – is that why the graph stops at 2000?
From the link:
” Data in each series were smoothed with a 30-year running mean. All data were then converted to anomalies by subtracting the mean of each series from that series. The overall mean series was then computed by simple averaging. ”
He is saying that a 30 year mean with simple averaging is superior to PCA and the other sophisticated techniques that the other researchers used????????? I wonder what the great white knight of statistical auditing would have to say about this? Hang on another update from SteveM – this study is supportive of the skeptics case ergo it is true and accurate in all details and needs no suditing – well thats a relief, I was just preparing for another round of hockey stick wars.
Ender – 18 peer reviewed, calibrated proxies are used – no dodgy, selected tree ring data. Doesn’t matter whether 10, 20 or 30 year smoothing is used – it ain’t no hockey stick
I think I’m with Ender in this. The axes of the graph need some explanation.
Does the ordinate really show years AD?
Are the “Degrees C” of the abscissa the same for the blue and red cueves.
The hadcrut3 figures I have are defined as “temperatures expressed as temperature anomaly (from the base period 1961-90) datasets.” And the 2007(incomplete) figure for the hadcrut3 anomly is 0.437 Deg C (monthly average).
This figure is somewhat consistent with the max value of the red curve shown above. So can one assume that the “Degrees C” are all defined as for the hadcrut3 series?
I said I wouldn’t but here’s a most appropriate quotation for many posting here…
“The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.”
– Tolstoy, The Kingdom of God is within you, Chap 3.
Sorry folks!
Luke said it first: There is no way known to man this level of detail on the global temperature curve was available even a hundred years ago.
The appeal of the analysis lies in its transparency. Just take eighteen 2000-year temperature records that meet predetermined criteria (from 4 continents plus Greenland and Caribbean, independently obtained and individually peer-reviewed) and average them. No fancy secret statistical manipulations, no hiding of source data, it’s all out there.
Sure, there could be uncertainties and errors in some or all of the source data, but if so, you would expect the analysis to fluctuate dramatically or collapse into noise when the simple tests for robustness or different filtering systems were applied.
The simplicity of the approach has certain PhDs howling, and even has McIntyre bemused. But what we have here is data that has not been cherry-picked and tortured beyond recognition in advance, and that can be built on with confidence if and when more data becomes available. Will future data, meeting the same criteria, contradict the Loehle analysis? Don’t bet on it.
nonsense!
Even if we accept the above graph as being correct, the problem is that temperatures are going to keep rising. That’s the problem.
For all its structural failings, there are a couple of key points to remember. This work uses proxies that are:
* Already temperature calibrated to the instrumental record
* Long term and self consistent (allowing the above calibration)
* Sourced from published work (i.e. peer review by now should have exposed flaws)
This approach therefore makes unnecessary any fancy statistical massaging of the actual proxies – so simple averaging (i.e. the same as applied to current global temperatures) is not inappropriate.
The other point to keep in mind is that this work supports the dozens (if not hundreds) of temperature estimates for the last 2000 years (that were compiled pre MBH98/99 and TAR – i.e. the ones that the AR1 “cartoon” was based on. http://www.global-warming-and-the-climate.com/images/climate-history-ipcc.gif )
The only argument that may be levied against this work is the fact that the proxies are heavily weighted to the Northern Hemisphere – and therefore no real conclusions can be made to the global extent of the MWP and LIA.
It may well be that the open audit that’s going on currently on CA over this may result in a structurally better paper incorporating a wider range of similar proxies (if they exist…!) to give it a more global feel.
It will be interesting to see what shape the rebuttal from RC etc will be – and I suggest they have to do one… otherwise there will be serious doubt introduced as to the hindcasting skill (and therefore forecasting skill) of the computer models used to predict the extreme temperature increases in the coming years.
cheers
Arnost
Paul – “18 peer reviewed, calibrated proxies are used – no dodgy, selected tree ring data.”
However he is selecting equally dodgy studies, if thats what you want to call them, and excluding an entire subset of proxies to get the sort of graph that you want.
From the paper:
“Data in each series were smoothed with a 30-year running mean. This should help remove noise due to dating and temperature estimation error. If data occurred every 100 years, each point would be stretched by the smoothing to cover 30 years. All data were then converted to anomalies by subtracting the mean of each series from that
series. This was done instead of using a tandardization date such as 1970 because series date intervals did not all line up or all extend to the same ending date. With only a single date over many decades and estimation error, a short interval for determining a zero date for anomaly calculations is not valid. The mean of the eighteen anomaly series was then computed for the period 1 to 1995 AD (smoothed values for 16 to 1980AD), since most series had complete records for this interval. When missing values were encountered, means were computed for the sites having data.”
So the data is smoothed in a way that I have heard skeptics decry as invalid when talking about global average temperatures – do you not recall the conversations about 30 year means being invalid. So here you are now agreeing with this researcher that now says simple 30 year means are superior to other forms of analysis.
Also why are these proxies inherently superior to tree rings. All of them are uncertain and require vast amounts of processing to derive a signal. The proxies that this person uses are far less certain than the, in comparision, well researched tree ring proxies and others that the multi proxy studies up until now have used.
Leaving an entire subset out just because you want a specific answer is just wrong and even then you seem to have to leave out the graph from 2000 to 2007 that shows warming in excess of the MWP.
“This work uses proxies that are:
* Already temperature calibrated to the instrumental record
* Long term and self consistent (allowing the above calibration)
* Sourced from published work (i.e. peer review by now should have exposed flaws)”
Absolute nonsense!
For this graph to have a valid comparison with current data and methods we would need millions of decent measurements from the past. I say again there is no such thing in real terms.
Back off now or tell us morons how we get such fine detail through out the period covered.
Ender – can I take your “However he is selecting equally dodgy studies” as your final word on this – i.e. do you consider any temperature reconstruction work that uses these proxies as dodgy?
And if the proxy data stops in the 70’s, can you please tell me how Loehle should extend it to 21 November 2007?
As to smoothing – applying the same smoothing to ALL the records (which are the same thing i.e. temperature anomalies), though hiding data – is fair enough. There is no smoothing that gives higher weights to some over the others which is the beef with PC analysis.
cheers
Arnost
SJT
“Even if we accept the above graph as being correct, the problem is that temperatures are going to keep rising. That’s the problem.”
Do you think there is zero chance of another ice age in the future?
Ender said, “So the data is smoothed in a way that I have heard skeptics decry as invalid when talking about global average temperatures – do you not recall the conversations about 30 year means being invalid. So here you are now agreeing with this researcher that now says simple 30 year means are superior to other forms of analysis.”
Which is his classic application of a test to the point of absurdity. The objections to 30 year smoothing were in respect of the trends over the past half century. And in particular, the use of 30 year smoothing to obscure the absence of any warming over the past decade.
To then turn around and claim that any objection to 30 year smoothing, in any context, must therefore invalidate the entirely legitimate use of such smoothing over a 2000 year sequence is pure sophistry.
Ender betrays his baggage, once again.
And the excuses that Luke dreams up for ignoring an outcome that does not serve his masters ends are pathetic. But whats new.
Paul, how do you explain the recovery to the ‘modern warm period’?
Gavin,
It may be cherry picking, but the work’s criteria for selection of these proxies is just that what I have stated. The beauty of this reconstruction is that is uses only proxies that have been temperature calibrated and have NOT BEEN CHALLENGED over many years in the scientific domain, i.e. they are used in lots of recent and canonical works such as Moberg 2005. Have a good read of the paper and a trawl through the CA (now multiple) posts on this and then have a real think about it to see if this really is nonsense. By the way, there is a search going on to find more proxies of the same type…
So your point is moot.
However, you may very well be right that using proxies to establish past temperatures is absolute nonsense. But would you therefore suggest that it may be better to rely on documented historical evidence such as the Vikings planting potatoes / wheat in what is now permafrost in Greenland and throw the IPCC reconstruction into the bin as similar “nonsense”?
To echo Ender’s point questioning the reason for using non tree ring proxies only – it is difficult to temperature calibrate tree rings directly. Tree growth responds to more than just temperature – they respond to water, humidity, wind/storms, diseases, and fertilisation etc. Trees also have an optimal temperature range for growth, and will produce thin rings when under stress from both a too cold AND a too WARM environment. The reason that tree rings can provide a hockey stick shape over the last 100 or so years is because of CO2 fertilisation. There is more “food” for them in a CO2 richer environment, and then regardless of the ambient temperature, the rings will be thicker. Consequently tree ring records require lots of massaging and assumptions to extract a temperature signal and thus ultimately are a poorer temperature proxy than those used in the Loehle work.
cheers
Arnost
Arnost – “can I take your “However he is selecting equally dodgy studies” as your final word on this – i.e. do you consider any temperature reconstruction work that uses these proxies as dodgy?”
No the proxies are the best we have and are necessarily noisy – I was using Paul’s words. I cannot see why 018 proxies and pollen proxies are superior to tree ring ones. Both require interpretation and calibration.
“And if the proxy data stops in the 70’s, can you please tell me how Loehle should extend it to 21 November 2007?”
I don’t know. Spencer grafted on the HADCRU3 data that does go to 2006 at least so why does Spencer’s graph only go to 2000.
Which brings up another question in the link to ClimateAudit that Paul provided http://www.climateaudit.org/?p=2393
all the graphs go to 2000 – so where did the extra 30 years of data come from if the proxies stopped in 1970?
“There is no smoothing that gives higher weights to some over the others which is the beef with PC analysis.”
But for a valid analysis this is exactly what you need to do. A classic case is electoral bounderies when people in country areas have a greater weight in voting if the electoral bounderies are not adjusted to try and incorporate the same amount of people within it. Some of the proxies have very strong signals and need to be adjusted more than simple averaging.
Arnost – “There is more “food” for them in a CO2 richer environment, and then regardless of the ambient temperature, the rings will be thicker.”
This is absolute rubbish. So what you are saying here is that tree growth only depends on CO2? So do the experiment – grow a tree in say 20% CO2 in pure brickies sand and don’t water it. See how it grows then.
CO2 fertilisation only works when the other conditions for growth are present in enough abundance to support the extra growth. You cannot possibly say that the tree rings will be thicker in high CO2 environments.
O18 ratios are also subject to environmental changes and are not actually exact temperature gauges as you seem to think.
A good primer is here:
http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.3.pdf.xpdf
Read and enjoy.
“Do you think there is zero chance of another ice age in the future?”
Of course there will be.
Ender – thanks for the reply…
“I cannot see why 018 proxies and pollen proxies are superior to tree ring ones. Both require interpretation and calibration.” I would very much agree.
As to “some of the proxies have very strong signals and need to be adjusted…” again on point, BUT this is an argument that cuts both ways. It may be that (say) the GRIP proxy in the Loehle series overrides the others, but an adjustment and especially through PCA, may give an already very strong shape higher weight (esp. as in MBHx etc) and so compund the error. I think that Loehle addressed this in the paper by his doing the 14 proxy random series to see if the shape materially changed…
It would be really interesting (on the basis of a graph like this) to trawl through the web and see if there are (human) documented records that would confirm some of the spikes and troughs. Any historians out there?
Interesting stuff – and generating a lot of activity :). A new post on CA where Steve Mc re-creates Moberg 2005 by adding the missing Loehle proxies (and removing non-temperature calibrated ones) – AND leaving tree rings in…
http://www.climateaudit.org/?p=2403
Still would love to see an RC (at least initial) take on this.
cheers
Arnost
Yeah “the beauty of this reconstruction is…etc”
Arnost: The only accurate temperature records we have are quite modern.
Lets spell it again for the newbies; I started instrument calibration as a career some fifty years ago, about the same time as our first geophysics year in fact and I have maintained a close watch on associates in the Antarctic expeditions, Cape Grim etc since. Also some of us downunder pioneered methods and standards used across industry (emissions too) as well as science. We are seeing today the results from programs commenced then.
This graph is an abortion from no such field of measurements. For starters, it purports to find steady states plus or minus point C over long periods which is nonsense of the first order given our most recent attempts to find meaningful global averages. Tree rings may give us climate patterns but not temperature comparisons with the present (btw I have seen a lot of freshly sawn ancient tree rings).
Arnost: Shorelines are still the best indicator of past temperature on a global scale so why not use them?
Ender
I – for a split second – thought we were going to have a rational conversation. But as it’s obvious that with you as with all the other AGW faithful it won’t be possible. All I see you doing is trying to discredit, obfuscate and misdirect at the least excuse…
I will make one last attempt and accept that I may have made a mistake and reword the sentence that so insensed you and prompted to “rubbish” me.
“[All other things being equal,] there is more “food” for them in a CO2 richer environment, and then regardless of the ambient temperature, the rings will be thicker.”
You know – the reason why they raise the CO2 levels in commercial greenhouses to produce better yield.
Oh – by the way, I have yet to see you acknowledge that anyone (on the other side) may have a good argument let alone acknowledge that you may be wrong.
cheers
Arnost
Gavin
I would actually go a bit further and suggest that even modern temperature records are flawed.
Though I would accept that shorelines may be a good way of measuring past temperatures on the short time scale, however once you get into the millenial scale, isostatic lift, continental drift and other tectonic changes may obsure the temperature driven changes completely.
cheers
Arnost
Arnost – “”[All other things being equal,] there is more “food” for them in a CO2 richer environment, and then regardless of the ambient temperature, the rings will be thicker.”
You know – the reason why they raise the CO2 levels in commercial greenhouses to produce better yield.”
All other things are not equal in nature. In fact if you increase the CO2 there is as yet no evidence that in a forest this would result in a sustained growth spurt as the higher growth would quickly deplete available resources:
http://www.esd.ornl.gov/facilities/ORNL-FACE/PCE1999.htm
“The relative effect of CO2 on aboveground dry mass was highly variable and greater than that indicated by most syntheses of seedling studies. Effects of CO2 concentration on static measures of response are confounded with the acceleration of ontogeny observed in elevated CO2. The trees in these open-top chamber experiments were in an exponential growth phase, and the large growth responses to elevated CO2 resulted from the compound interest associated with an increasing leaf area. This effect cannot be expected to persist in a closed-canopy forest where growth potential is constrained by a steady-state leaf area index. A more robust and informative measure of tree growth in these experiments is the annual increment in wood mass per unit leaf area, which increased 27% in elevated CO2. There is no support for the conclusion from many seedlings studies that root-to-shoot ratio is increased by elevated CO2; fine root production may be enhanced, but it is not clear that this response would persist in a forest. Foliar nitrogen concentrations were lower in CO2-enriched trees, but to a lesser extent than was indicated in seedling studies and only when expressed on a leaf mass basis’
Your blanket statement that CO2 would result in higher growth has no basis in the science of real world forests.
If you want a rational discussion how about you keep to statements that you can support with evidence.
Ender
Your point that higher growth depletes available resources and therefore can’t be sustained… over what period? One week? One year? One millenium?
In the above abstract this point is not mentioned. You are misdirecting again.
On the other hand, my claim that trees produce thicker rings in a CO2 richer environment [all things being equal] is: “that more robust and informative measure of tree growth in these experiments is the annual increment in wood mass … which increased 27% in elevated CO2”.
cheers
Arnost
Ender
Ypu justr posted
“and the large growth responses to elevated CO2 resulted from the compound interest associated with an increasing leaf area.”
Which confirms what Arnost said, are you actually reading the cut and pastes you use?
Ender: One of the sawmills I visited regularly after work looking for dissguarded burls was just outside Zeehan. There they cut a lot of King Billy pine salvaged from hydro developments not too far from the famous patch on Mt Reid. How any one can see temperature over water and light in any of those rings, still amazes me (see John Daly etc). Seedling versus understory is a whole new guessing game with these stunted trees too.
Back to calibration:
Arnost: Thermometers in the 1960’s although linear in most cases (mercury in glass or steel) were +/- one% at best, recorders likewise. Direct readings probably doubled those errors. A handful of instrument manufacturing companies world wide, each with their own handful of field technicians became critical in overhauling the situation. Engineering, not science drove performance and reliability of individual instruments over time for all field measurements. Note too; we had nothing much automated before the advent of electricity.
Referring backwards to manual methods is something I do a lot. It allows us to create standards on the spot and a fresh view of tiered systems. The big barrier in many measurements is knowing the magnitude of errors or at least the likely magnitude. We use at minimum a system of three independent standards. None of this is apparent above.
You should at least look for the largest upset like we had about 8-10,000 years back before calibrating.
Arnost – “that more robust and informative measure of tree growth in these experiments is the annual increment in wood mass … which increased 27% in elevated CO2″.”
Yes but you seem to have missed both of these:
“but it is not clear that this response would persist in a forest.”
“This effect cannot be expected to persist in a closed-canopy forest where growth potential is constrained by a steady-state leaf area index”
which means that in the real world other contraints limit the CO2 increased growth. It may deposit one or maybe 2 larger rings however this increased growth would not be sustained and also if proper statistical techniques were used would tend to be averaged out. Which really points out the requirement for properly weighted statistics instead of simple averages.
Paul – “Which confirms what Arnost said, are you actually reading the cut and pastes you use?”
Yes I do because the reference states that there is no evidence that these growth rates would happen in a real forest where other factors are constrained which is exactly my point.
Ender
Your source says nothing about time and does not support your phrase “increased growth would not be sustained” and is specific to 1 type of forest only.
Ender,
Obviously if you pile on constraints, they will constrain. From what I understand from the above, all it really says that:
In a CO2 rich environment, the trees would undergo EXPONENTIAL growth until such time that the steady-state leaf area index is reached (i.e. where the leaves block the sunlight thus preventing photosynthesis in other leaves).
So it will happen in ANY real forest UNDER the leaf area index. And it certainly will happen to the trees typically used in dendochronology and temperature reconstructions as they are NEVER in a closed canopy environment.
The point that you are attempting to distract from and obfuscate stands. The Bristlecones ARE subject to CO2 fertilisation and it is THIS that increases their tree-rings. Their use as as the most weighted temperature proxy is one of THE keys to generating the Hockey Stick.
cheers
Arnost
Regarding all the fish in Moondara Dam that died this winter from cold, my Nimbin friend’s mature mango trees that died from cold and similar, my oenological correspondent remarks on the NZ winery that had its harvest wiped out by cold:
The comment “We have been trailing new methods though to get better fruit set even though you can’t drastically alter flowering or conditions.” Tells it all. Fruit set depends upon leaf area and cool conditions prior to fruit set reduce leaf and shoot establishment. The vine is thrown back upon its stored reserves and there is too much competition for carbohydrate from growing points when the fruit is being set. We saw this problem on a Chardonnay and Merlot in 2005 when the SOI briefly coursed upwards. A hell of a lot of grapegrowers who have established in cooler areas since 1976 will experience these sorts of worries during SC 24.
Real people doing real things are having their lives and livlihoods disrupted by the coldening that is already upon us.
Paul posted the article at 03:32 AM and by 05:28 AM Luke was already ‘ROTFLing’.
I don’t wish to be unkind but, honestly Luke, you ought to get a life.
Why is evidence that the current modest warming may be well within natural fluctuations, whatever the cause (or ‘climate variation’ as Luke would call it), so unwelcome to some?
There were four known supernova events internal to the Milky Way; 1006, 1056, 1572, 1604. So you can compare those historic events directly.
I am aware of records of Nile River flooding, kept by the Egyptians, which could be compared. American Indians didn’t have written language so no help there, but the Chinese, Indian (from India), and Japanese, kept records. I wouldn’t be surprised if the Iraqis have records for the Tigrus Euphrates system over much of this time frame as well.
That point that Paul makes that the Mannian climate reconstruction would have amounted to centuries of cold is one I hadn’t thought of before. We would have passed a few ice field tipping points and been well into the modern ice age if MBH99 were true.
So why are bristlecones CO2 fertilised. Says who?
James has got a sample size of 4 – E&E will publish that I’m sure. ROTFL.
Steve McIntyre’s post on the CO2 fertilization adjustment in MBH99, with reference to Graybill and Idso, 1993.
http://www.climateaudit.org/index.php?p=39
chrisgo: Since when has a slice of wood been an instrument for measuring say the interior of your fridge? Given any slice of pine, you have no idea of its environment except that it grew in the range minus something to plus something somewhere.
At best we have growth rings calibrated over decades of temperature measurements. Individual giants differ greatly even in a forest considering canopy and root mass. Very few studies consider the life of root systems and interruptions like lightening strikes that are frequent enough to reduce competition in bad growth periods i.e. dry spells.
Fallen giants however do tell us a great deal about forests and conditions in earlier times. From observations in my own bush patch I know there are no comparisons between trees say 80-100 yo trees and trees three or more times their bulk in a previous natural forest.
How do we know when a piece of wood had optimum development?
Arnost – “The Bristlecones ARE subject to CO2 fertilisation and it is THIS that increases their tree-rings. Their use as as the most weighted temperature proxy is one of THE keys to generating the Hockey Stick.”
I cannot believe that you can still cling to this whopper. How would bristlecone pine fertilization affect a glacier proxy reconstruction that has almost the same result.
Thats enough anyway – I am not getting sucked into yet another crap war of this proxy and that. It was done to death years ago and I really surprised you haven’t got over it.
They really have to kidding. CO2 isn’t Jack’s Beanstalk – fertilisation effects are very complicated. In a resource limited alpine environment I wouldn’t believe you’d get any effect unless you stuck a tree in a FACE experiment and showed me.
Luke: I keep asking myself what was the MWP downunder?
McIntyre v a Mannian scientist over at CA:
JEG writes:
Please let me re-state the angle of my review. It is : does this paper meet basic criteria for publication in a climate journal, say any AGU or AMS publication ? Some experienced authors may want to correct me here, but my criteria have always been :
1) is the approach novel ?
2) is the methodology described with enough detail ?
3) are all important choices justified ?
4) are the uncertainties appropriately discussed ?
5) are the conclusions warranted by the analysis ?
In the case of Loehle’s paper :
1) yes
2) no
3) maybe
4) absolutely not
5) absolutely not
Let’s discuss academic reviewing and maybe I’ll start a thread on this. Let me start by saying that I feel like an anthropologist when I see the form and style of journal peer reviews because I didn’t grow up in that system. I never wrote an academic article until I was over 55 and my first encounters with academic peer review came after I had had lengthy experience with due diligence on prospectuses, financial statements, business feasibility studies – all done differently than journal peer review.
I don’t view journal peer review as a bad thing, only as very casual. I’ve reviewed a couple of papers at Climatic Change and, as a result, Climatic Change changed their policies and now require authors to make data available. I asked to see supporting data and source code in one review (which authors are required to submit in econometrics); Stephen Schneider said that no reviewer had ever asked for those things in 28 years and refused to ask the authors for code. In one case, the authors actually withdrew the paper rather than provide supporting data.
In business, there are a lot of important documents that are not “novel” in an academic sense. My own sense of the present situation in climate science is that the demand for novelty is not necessarily relevant. For example, let’s consider the Almagre core that we’ve collected. The principal interest is really just the data. We can comment on the data, but I don’t think that it would behoove us to try to do anything “novel”. That would introduce an irrelevant variation.
Your next criteria:
2) is the methodology described with enough detail ?
3) are all important choices justified ?
I completely agree that these are important issues. Obviously proxy climate science has a disastrous history in this respect. Methodologies are consistently described not merely with inadequate detail, but even inaccurately. (This is one of the reasons that I want to see source code – contrary to perception, it’s not to nitpick, it’s to find out what the authors actually did, as opposed to what they say they did.) I probably have more experience than anyone in assessing whether a methodology is described in enough detail to permit replication. HOw does Loehle compare with the predecessor articles? Relatively well. I’ve come close to replicating his results; so the methods need to be clarified further. But I’ve been completely unable to decode MBH99 confidence interval calculations or how Mann and Jones 2003 works. So on issue (2) – having actually dug into it, I think that Loehle could readily amend his article to meet the standards that you and I seem to share.
As to the justification of choices, I’m not sure how you differentiate this from methods. Loehle described his selection criteria (something that I construe as part of methods). Is this what you have in mind?
Are the uncertainties appropriately discussed?
This is a real conundrum because, in my opinion, uncertainties are not appropriately discussed in any proxy reconstruction article. MBH98 reports uncertainties but its methodology is incorrect and thus not “appropriate”. MBH99 reports uncertainties but no one knows how the uncertainties were calculated. I’m not sure that anyone really knows how to calculate uncertainties for these reconstructions right now.
This puts a fair reviewer in a bit of a conundrum. Can a reviewer use a defect that affects an entire discipline to prevent publication of an article that in this respect is no better and no worse than other entrants. Here the reviewer should be conscious of whether his views are being affected by adverse personal interests. For example, JEG is expressing a sensible objective here, but is he using this ostensible objective primarily as a trade restraint i.e. to discourage publication of an article primarily because it is presenting an MWP? (I’ve got an idea here. If JEG can explain to us how MBH99 confidence intervals are calculated, maybe we can get this methodology applied to Loehle.)
are the conclusions warranted by the analysis ?
I don;t think that Loehle can, with any confidence, claim that the MWP was warmer than the 20th century any more than Mann can claim that the 1990s were the warmest decade of the millennium. I would certainly have made a more nuanced conclusion.
It seems to me that JEG’s detection of an unsupported conclusion is much acute in an adverse article. Unsupported conclusions occur elsewhere without JEG being troubled. That is not an argument against supporting the conclusions BTW – just an aside.)
JEG studiously avoids the consideration of precedents – something that is very important in legal decisions where judgement is also involved. If journals have consistently approved articles in a field that do not meet the standards that JEG and I aspire to, at what point would we as reviewers have the right to unilaterally raise the hurdles for the entire field? In such circumstances, I think that a reviewer can fairly do this only to articles that he does not oppose. So for example, if JEG were reviewing an article by Mann or Ammann and he wanted to use that occasion to draw a line in the sand and get them to meet the above standards, no one would argue about it. But if he’s doing it to an article adverse in interest and his new righteousness has the effect of suppressing an article that shows an elevated MWP while otherwise being indistinguishable from something by Hegerl or Esper etc, then it’s probably not fair.
Has JEG supported his allegation of “pseudo science”.? It doesn’t seem to me that he has.
Maybe the correct course of action is to try to find proxies that are actually responding to local temperature, rather than teleconnecting. For example, we don’t estimate the temperature in Chicago by measuring rainfall in Thailand, even though there may be some teleconnection.
Let’s grant JEG the premise that (say) a coral dO18 somewhere is teleconnected to ENSO. If that relationship is established in a third party article and the calibration to some intermediate variable can be sensibly used in a model, then maybe it would have some utility in a properly constructed model. But the third party calibration should be a datum to the reconstruction rather than one of ten thousand coefficients calculated from a Mannian multivatiate calculation.
My guess is that the attempt to utilize confounded proxies is somewhat of a blind alley and the most pressing need is to develop better temperature proxies – perhaps Mg-Ca is a step in that direction.
Ender – we don’t measure global average temperature in Australia. We have good evidence of the LIA in Oz, and Oz has only experienced half of the the modern warming of the Northern Hemisphere. So, yes – each region has its own average temperature, but on the basis of a global average temperature there is evidence for a global effect of warming or cooling periods.
We seem to be short of data down-under:
Williams, P.W., King, D.N.T., Zhao, J.-X. and Collerson, K.D. 2004. Speleothem master chronologies: combined Holocene 18O and 13C records from the North Island of New Zealand and their palaeoenvironmental interpretation. The Holocene 14: 194-208:
Temperatures were inferred from δ18O data obtained from four stalagmites found in caves at Waitomo (38.3°S, 175.1°E) on New Zealand’s North Island for which 19 TIMS uranium series ages were measured. The Medieval Warm Period occurred between AD 1100 and 1400 and was warmer than the Current Warm Period.
Wilson, A.T., Hendy, C.H. and Reynolds, C.P. 1979. Short-term climate change and New Zealand temperatures during the last millennium. Nature 279: 315-317:
Temperatures derived from an 18O/16O profile through a stalagmite found in a New Zealand cave (40.67°S, 172.43°E) revealed the Medieval Warm Period to have occurred between AD 1050 and 1400 and to have been 0.75°C warmer than the Current Warm Period.
The certainty about paleoclimate expressed by the IPCC is not based on an objective assessment of the available paleoclimate data and its flaws.
I’d be happy if the IPCC just said that ‘we don’t really know,’ rather than adopting a false position in order to back up the CO2 hypothesis and climate alarmism.
Paul,
If these two reconstructions are calibrated to temperatures – and it appears that the second is given you say that it’s “0.75°C warmer than the Current Warm Period” – and if the data is archived, then this is exactly what Craig Loehle is looking for.
Steve Mc said he would start a thread where data such as this could be saved… keep this in mind.
(And a favour please? Don’t refer to Dr Emile-Geay as a “Mannian” scientist… sets a bad example)
cheers
Arnost
Enders attempted side step on tree rings and CO2 fertilisation, once again, extrapolates from limited and specific instances.
The limits on growth mentioned in his link only apply to closed forests. Most of the worlds forests are not closed forests, least of all, Bristlecones. And even those that are closed face an increasing incidence of wildfire, in which case all bets are off.
Less than 2% of Australian forests are anywhere near closed forests. And even those that are will have canopy cover in the order of 85% rather than 100%. And that 85% still allows scope for a structural change in both canopy cover and canopy height leading to both higher basal area and higher stored carbon volume.
But those who insist on using tree rings as temperature proxies must explain how they would detect a temperature increase that was combined with wetter climate that manifest itself in a taller forest. The rings would be the same at the base of the tree but the growth response would all take place at the top.
Indeed, the point when growth appears to slow, as measured by diameter change at breast height, does not mark the start of senescence. It merely marks a structural change in growth habit where most growth is shifted to the large branches that enable the tree to dominate its site.
It is just that ill-informed departmental boofheads are only capable of observing the obvious, at ground level. And that is generally where the ring cores are also taken.
Yes well – la de dah – but we’e not talking the situation are we. We talking sparsely separated long lived trees of modest height on some remote rocky peak.If it’s a shallow soil water limited environment CO2 woun’t be doing much turbo boosting. Is there an ecophysiologist in the house?
Mannian style pseudo-science error bars now added:
http://signals.auditblogs.com/files/2007/11/l07.png
Re Luke’s “shallow soil water limited environment”.
A comment heard from from Prof. Harold Heady is relevant – it was to the effect that “Just because a tree is growing in a rocky situation, don’t assume it is water-limited”
True – but if it’s not limiting then you’d expect a sizeable tree?
Paul – what are we even looking at? Those noisy series produces those error bars?
Original Hockey Stick graphs had much wider error bounds??
And Paul while you’re there – assume the graph is correct in the real world for sake of argument. What’s the drivers for these MWP and LIA scale temperature shifts – solar output, orbital changes (and hence solar), volcanism ? And how much internal climate variation should we expect from the climate system in a “unperturbed” state. (Yes Chrisgo, the internal climate variation is called climate “variability” – not a new term).
Whaterrorbars?
Paul: Your thick highlighter tip won’t pass. Sorry.
Paul – “we don’t measure global average temperature in Australia. We have good evidence of the LIA in Oz, and Oz has only experienced half of the the modern warming of the Northern Hemisphere. So, yes – each region has its own average temperature, but on the basis of a global average temperature there is evidence for a global effect of warming or cooling periods.”
We contribute data to the global average temperatures as the BOM is highly respected in the international weather community. We only have experienced half the warming because we have much more ocean.
“I’d be happy if the IPCC just said that ‘we don’t really know,’ rather than adopting a false position in order to back up the CO2 hypothesis and climate alarmism.”
If you read it properly that is almost exactly what they do say. That is why there is scenerios as nobody knows for sure. The CO2 hypothesis is far better grounded in solid science than any rival theories. In the absence of any better science the Enhanced Greenhouse Effect is the best working hypothesis we have.
It would be far more irresponsible to assume that recent warming is solely from solar variations, proceed to emit as much greenhouse gases as we like, and then it turn out to be greenhouse gases after all.
Are you absolutely 100% sure that recent warming has nothing to do with greenhouse gases?
Luke said, “We talking sparsely separated long lived trees of modest height on some remote rocky peak”.
Yes, the very trees that have a multitude of growth options, from increased height to increased girth, etc. The very opposite to the ones in closed forests that are theoretically limited by site.
But that won’t stop the planet plodders from arguing that black is the new white.
Just to ram the stake into the vampire’s heart, trees responses to growth can result in a range of different tapers in the trunk. In wide open sites the taper (ie, reduction in diameter the furthur up the trunk one measures) can be as high as 6%. That is, a 6cm reduction in diameter for each one metre interval along the trunk.
In closed forests this will normally drop to about 1% but it can go as low as 0.25% or only 2.5mm reduction for each metre of height. And this change in taper can take place at different times in the trees life.
So a sequence of tree rings showing a gradual reduction in the thickness of growth rings will mask a structural shift in where the growth is taking place. And it would only take a lightning strike in a neighbouring tree, to shear off a large branch, and the tree beside it will have a powerful motive to direct growth into the quadrant closest to the new gap in the canopy.
So if a core sample was taken in that particular quadrant, then it would be recorded by ill-informed climate wallys as a period of warm climate. But on the balance of probability, the core would be taken in one of the other quadrants and be recorded as a rather convenient period of cool climate. The better to scare the kids with portents of doom.
The key point is that the range of variation between a 0.25% taper and a 6% taper is far greater than all but the most extreme climatic changes. And one can only conclude that a tree ring proxy for past climate change is only one step up from voodoo.
I’m sorry to refer back to a previous thread, but Luke’s comment November 18,
“Meanwhile I see Bangladeshis have enjoyed their adaptation to a bit of the ol’ climate variation again…” brings up a point which, I think, goes to the logical fallacies perpetrated (innocently or cynically) by the AGW crowd.
We know that Hurricane Katrina was caused by ‘global warming’ (aka ‘climate change’) i.e. by the greenhouse gases emitted by the US and Australia (specifically by Bush and Howard not ratifying Kyoto) – Nobel Prize winner Al Gore said so in his Academy Award winning movie.
But the Bangladeshi cyclone was due to “internal” climate variation.
There is a form of circular reasoning going on here, where the conclusions are assumed in the premise.
Surely all climate events are due to ‘internal climate variation’ until proved otherwise and that is the very point of this contentious issue.
And if we assume the 2000 year record above is as accurate as any can be, does it matter if the warming in the last century, say, is due to anthropogenic greenhouse gases (specifically CO²)?
That’s CO₂.
Some advantages of the Loehle’07 proxies…
1) The were ~18 for nearly the entire reconstruction period — previous Mann et. al. and others were much less!
2) All proxies were calibrated with the instrument record — previous Mann et. al. and other recon’s had exception series!
3) All were relatively anthropogenically-isolated sea/ocean series — no land-based, UHI-suspicious/tainted, or even riverine locations with the potential for human factors influence! And with >70% of earth’s surface being H20, would you ask for anything less?
4) No BCP or Foxtail pine (strip bark) series — arguably poor temp proxies, with proven enhanced CO2 sensitivity, they are now removed from the stat pool. In fact, since Mann et.al. recon’s require strip bark series to achieve hockey stick shape (while under-reporting temps of say, the MWP), much HS criticism is diffused.
5) During the modern instrument period 1979-present, each Loehle’07 series behave much like tree-ring series … IOW, they all exhibit the same “divergence” from the extraordinary claim, “1990s, the decade in 1000 years!”
6) There is no statistical PC1 bias due to “strip bark” series inclusion. In fact, Loehle’07 , shows no apparent stat preference (or out-of-balance contribution) from any of the series. Mann et.al. require “strip bark” series to get his PC1.
7) The supplemental errors bars, have at least as much meaning as Mann et.al. (IOW, not much – but that is another story)!
8) ?
9) ?
10) The results have the ignorant Lil talking in circles, again; and now Mr Ender has joined the circle of AGW zealots talking in circles. One has to appreciate the geometric epidemiology of that.
=====
Mr Mott-
It’s near time that your theory would predict an explosion of cut’n’paste quoted posts. The usual suspects are clearly in over their head, and will be tossing big quotes (many unattributed by the copyright challenged Lil Lukefish) like life bouys to reinforce subsequent hand-waving.
Reminder (pointed out by Mr Biggs): 10, 20, 30 year running averages, all showed similar trend/event transitions and changes. The longer averaging periods just smoothed things, as expected…
http://www.climateaudit.org/?p=2393 (near bottom of topic post).
4 & 6 above, could arguably be combined … leaving 3 to fill in by others not physical science challenge!
Correction: “life bUOys to reinforce…”
and correction: “1990s, the WARMEST decade in 1000 years!”
See Chooky Hawk is back after get pooned like a newb on cryospheric crevasses.
And now it’s “Mr Mott” …. oooo “Mr Mott”… oooo swoon. Hey Chooky Hawk – maybe Mottsa will win many senate seats in the upcoming election and declare independent thinking illegal. oooo oooo ….
Let’s see did Mottsa say anything today of interest. Some days he does. Nope – had a mensuration rant about having a pointy head or something – didn’t address CO2. Found all sorts of very interesting things about CO2 fertilisation yesterday but we’ll keep that powder dry for a while.
“Proven enhanced CO2 fertilisation” – yea sure – dream on ecophysiological ignormai.
Chrisgo – yes normal form would not be to attribute any single event to AGW and go with trend being the issue.
However – http://www.ucar.edu/news/releases/2006/hurricanes.shtml is very interesting. May have to be annoying and recant.
“See Chooky Hawk………………………………………………….. ecophysiological ignormai.”
Did anyone (including the author) understand any of that?
Well… it’s a week since the Loehle paper came out and there’s deafening silence on the usual warmist sites.
Looks to me like like this one has got them stumped.
I repeat what I said earlier:
It will be interesting to see what shape the rebuttal from RC etc will be – and I suggest they have to do one… otherwise there will be serious doubt introduced as to the hindcasting skill (and therefore forecasting skill) of the computer models used to predict the extreme temperature increases in the coming years.
cheers
Arnost
Luke, in the manner favoured by the vacuous, chooses to ignore information that does not support his prejudices by declaring them to be “not of interest”. This ploy is used in conjunction with that more familiar cop-out, declaring fully substantiated detail as “booring”.
Just another day in the pointless life of our saddest little broomstick cowboy.
Thanks, Mccall, Ian will do fine, otherwise I might think you are talking about my father.
OK – I’ve had a bit of time to reflect and as this blog does not allow edits, I apologise for using the perforative “warmist”.
Further, I’d like to thank James Mayeau and Paul Williams for excellent posts supporting some of my previous arguments. I also appologise for the fact that I did not acknowledge these immediately.
Contritely yours
Arnost
DOH – perforative => pejorative
I can edit comments, and do if asked.
mccall – “It’s near time that your theory would predict an explosion of cut’n’paste quoted posts. The usual suspects are clearly in over their head, and will be tossing big quotes (many unattributed by the copyright challenged Lil Lukefish) like life bouys to reinforce subsequent hand-waving.”
No everyone is just sick to death of this crap. You have one minor side issue that you understand and you grind it to death coming out with exactly the same arguments years after most of this shit was put to rest.
The real issue is AGW. As you obviously have no alternative theory to account for recent warming you need an area with there is genuine doubt to bang on about therefore injecting doubt into the whole debate.
No-one will go down this obsessive road with you. Serious scientists do not debate with McIntyre any more as there is no point.
“otherwise there will be serious doubt introduced as to the hindcasting skill (and therefore forecasting skill) of the computer models used to predict the extreme temperature increases in the coming years.”
Arnost – please explain ! What prior papers are now in doubt?
Luke – was talking about models…
It seems to me that if you actually have a Loehle type paleo temp history, then the models that hindcast a Mann type paleo temp history (driven by high climate sensitivity to CO2) will no longer show the same skill. And therefore they will also have poor skill at forecasting.
So does a Hockey Stick curve parameterise a GCM?
I thought it was just “an” analysis.
Some paleo history e.g. PETM and Royer do show high sensitivity to CO2 as well. But it’s not that simple – climate comes from a mixture of forcings – solar output, orbital, CO2, volcanism … and different forcings at different times. Are we back on the ol’ it has to be (a) NOT (b) versus sometimes (a and b) or sometimes (a) or sometimes (b)
Are you guys exclusivists ?
So what’s your theory for the MWP and LIA – internal variation or external forcing?
Arnost what are the IPCC cited papers (or others) that show GCMs tracking Mann curves. Just asking.
Ender said, “Serious scientists do not debate with McIntyre any more as there is no point”. Yes, I agree, SERIOUS scientists have neither need nor motive to “debate” hard, properly validated facts.
Climate Clowns, on the other hand, have some sort of sad emotional need to wallow in speculation, untested assumption, unreliable proxies and coersion masquerading as consensus.
And in answer to Luke’s little flourish in questioning what has caused the last few centuries of warming, if not CO2, a reasonable person observing the above graph is likely to conclude that most of it was caused by an absence of, or change in, the circumstances that produced the preceding cold period.
The climate modellers have used a highly fallacious argument in justifying CO2 forcing on the basis of an inability to correlate past warming with aspects of solar forcing. And this allows a gonzo logic to imply that the “new” factor in the recent warming is CO2.
But we do know that the little ice age was not caused by insufficient CO2 emissions. The mix of other drivers caused the MWP and a change in that mix caused the little ice age. And it follows that a further change in that mix produced most of the temperature rise from that low point.
So why should we be expected to believe that this entirely natural warming cycle was apparently completely switched off the moment CO2 emissions began to rise?
You’ve missed the point.
CO2 is not a new factor.
What exactly in science terms is a “entirely natural warming cycle ” – very serious question?
Does the world suddenly go walkabout?
“why should we be expected to believe ” – oh just a gigaton of papers citing diverse lines of evidence – nothing else.
How reliable is the result given the data set?
“Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century. The eighteen series used here show a mean difference of about 0.3°C between the MWP and the 20th century (range of 0 to 0.6°C difference over the periods). It must be emphasized, of course, that this result is based on limited data.”
Sounds like this guy is saying – ‘ I found the data which shows MWP is warmer than today, but i’m not realy sure if its reliable’.
Also…
“Some of the input data were also integrated values or sampled at wide intervals. Thus it is not possible to compare recent annual data to this figure to ask about anomalous years or decades. The data show the Medieval Warm Period (MWP) and Little Ice Age (LIA) quite clearly. The series ends with a downtick because the last set of points are averages that include the cool decades of the 1960s and 1970s.”
seems to be an admission that the author is not confident that todays temps are less than the MWP and in fact, the data and how it has been analysed is not useful for answering that question.
Lastly, there is absolutely nothing in here about what is driving the temperatures and what the implications are for the burning question: ‘to reduce emissions or not to reduce emissions’. Ergo, no conclusion can be drawn on the robustness of AGW etc etc ad nauseum.
moving on!
Anthony
“Lastly, there is absolutely nothing in here about what is driving the temperatures and what the implications are for the burning question: ‘to reduce emissions or not to reduce emissions’. Ergo, no conclusion can be drawn on the robustness of AGW etc etc ad nauseum.”
Why would you expect to see such analysis in a temperrature reconstruction study?
Maybe the AGW people, given that this doesnt explicitly denounce AGW theory, can claim it as part of the ‘consesnsus’.
The big worry with Loehle’s stuff is that it’s published in E&E. I mean really. Does he want to be taken seriously or not. The last refuge of scoundrels. Which is why I believe you haven’t heard anything Arnost …
Luke avoids the issue, again. The GCMs, and the IPCC, are now claiming 90% certainty (albeit plucked from their bums) that ALL recent temperature rises are from AGW.
So when did the little ice age correction stop and the AGW start? The warming trend was already there so when, and why, did it stop?
Maybe it was just polite. “after you, no no no, I insist”? Oh Dopi Wan? Calling all boy wonders?
I can’t type when I’m laughing. What a card.
What’s an “little ice age correction” mean?
Does the Earth wake up one day and say “I’ve been in a bit of an anomaly and need to give myself a good correction”?
WTF does “a correction” mean (you know in science terms – none of this Gaia shit).
{as an aside that was a pretty silly analogy as the Earth is always awake somehere – except at Byron shire}
No Paul, I wouldn’t. Equally, I wouldn’t expect to see anyone on this thread pointing at this paper and somehow thinking its a serious challenge to AGW and lets face it, the subtext of the thread is “look, its been as warm or warmer before, the warming we are experiencing is either not significant and/or explained away as natural variation.”
All the paper has said is here is some data which says X. I am not confident this is a meaningful or robust result. As you were
Oh Ok
I think the paper is useful in challenging the idea that somehow we are in a ‘unprecedented’ warm period.
As you were.
Just because we can’t perfectly explain and detail what is an “entirely natural warming cycle” does not mean that it did not / does not occur.
There are lots studies that used tree-ring, speleothems and glaciological reconstructions that are supported by historical, archaeological, and botanical records from various parts of the world showing there WAS a MWP and that it WAS as warm if not warmer than present.
China:
http://www.springerlink.com/content/gh98230822m7g01l/
North America
http://www.crf-usa.org/bria/bria18_4c.htm
http://www.springerlink.com/content/g3j202757k464t41/
Central America:
http://www.nature.com/nature/journal/v375/n6530/abs/375391a0.html
South America:
http://academic.emporia.edu/aberjame/ice/lec19/fig19d.htm
New Zealand:
http://www.agu.org/pubs/crossref/2002/2001GL014580.shtml
Africa
http://www.nature.com/nature/journal/v403/n6768/full/403410a0.html
http://hol.sagepub.com/cgi/content/abstract/2/3/271
The list can go on and on in contrast “Hockey Stick” reconstructions (that don’t depend on the MBH proxy set and Mann’s statistics) are few and far between.
Though we may not know exactly what caused the MWP, but trying to suppress it (effectively rewriting of history) just to make the only “logical” explanation for the current warming fit better or to maintain credibility – is hubris of the highest order.
The no MWP mantra is one of my bugbears. I am reasonably well read and the hockey stick interpretation of past temperatures is just so anti all the historical records that I have come across. I really don’t understand why there is this great need for it to be suppressed within the climate science community (for example see the recent post on Rabett Run) – unless its existence precludes the existence of “something” necessary today. And I’m guessing that that “something” is the hindcasting / forecasting skill of the computer models projecting the 4C + increase in temps this century.
Cheers
Arnost
The blog just ate my last post that I spent nearly an hour on.
Luke – if an error is pointed out then regardless of how it’s pointed out it’s still an error and should be addressed.
I note that Mcintyre points in Mann et al 2007 the rain in Maine still falls mainly on the on the Seine. But because it’s on a blog it can safely be ignored. Is this right?
Yep. Doesn’t exist.
Arnost’s post is now published.
Just because we can’t perfectly explain and detail what is an “entirely natural warming cycle” does not mean that it did not / does not occur.
There are lots studies that used tree-ring, speleothem and glaciological reconstructions that are supported by historical, archaeological, and botanical records from various parts of the world showing there WAS a MWP and that it WAS as warm if not warmer than present.
We may not know exactly what caused the MWP, but trying to suppress its existence (effectively rewriting history) just to make the only “logical” explanation for the current warming fit better or to maintain credibility – is hubris of the highest order.
The no MWP mantra is one of my bugbears. I am reasonably well read and the hockey stick interpretation of past temperatures is just so anti all the historical records that I have come across. I really don’t understand why there is this great need for it to be suppressed within the climate science community (for example see a recent post on Rabett Run) – unless its existence precludes the existence of “something” necessary today. And I’m guessing that that “something” is the hindcasting / forecasting skill of the computer models.
cheers
Arnost
Arnost – surely you don’t “just have” variability of the order of MWP and LIA as a random wobble. This “natural” stuff is TOTALLY unscientific and unsatisfying. If you want to invoke “natural” might as well stop discussing as everything could be just “natural” coz God decided we’d have a wobble.
Want to go here Arnost and we’re into witchcraft.
As for “And I’m guessing that that “something” is the hindcasting / forecasting skill of the computer models projecting the 4C + increase in temps this century” – maybe there is but again if you want to have a scientific discussion this is totally unsatisfactory.
When I’m making a run on some isse here I like to back it up with some reviewed research otherwise it’s just hearsay or opinion.
Now I’m not saying you’re not right – but I’m unaware GCMs have been parameterised on a Hockey Stick. You show me. You’re running a conspiracy theory that suits your world view but with no evidence. Not science. They have used GCMs to understand past climates but that’s a different thing.
SO I keep coming back to it
(1) what’s this “natural” thingy really mean
(2) can we have a random walk the size of the LIA or MWP for no reason than “inherent internal variability”
(3) where do GCMs get tuned on Hockey Sticks?
And trying for a sensible discussion.
It’s all about chapter ….
OK – off the top of my head to baseline the argument and start (and of course everyone is welcome to chip in and support and correct).
Point 1 – There is reviewed research in my original post that Paul kindly resurrected which purports that a MWP and LIA existed. The amount of this type of research overwhelms the recent low temperature variability papers – plus it is supported by eyewitness records etc etc.
Point 2 – The suggested magnitude is such that it would preclude a simple chaotic “inherent internal variability” explanation.
Point 3 – We are left with an unescapable conclusion that there was an internal/external forcing that contributed to this temperature variability.
And so we are left with the dilemma of figuring out / deducing what this forcing was/is.
Point 4 – We can eliminate Earth orbital eccentricities (i.e. Milankovic cycles) as they operate on far longer timescales.
Point 5 – We can eliminate the fingerprint of CO2 in the MWP & LIA (note bene: I am not saying we can therefore eliminate the fingerprint in the current warming period).
Point 6 – We can eliminate the direct influence of surface volcanic activity since it principally causes a cooling plus the known records do not indicate a significant change in the average incidence and magnitudes. (note bene: I did not say we can eliminate sub-surface volcanic activity)
Point 7 – We can eliminate the direct influence of Solar Irradiation as the suns activity, though fluctuating, is unlikely to vary to such an extent that it would cause climate variability of such magnitude as observed in the MWP and LIA. (note bene: I did not say we can eliminate other solar influences direct or indirect)
Point 8 – We can eliminate land use changes as there it was not until after the LIA that significant anthro changes occurred.
Point 9 – We can eliminate oil spill oceanic polution / kreigsmarine effects (see http://www.ocean-climate-law.com/seaclimate/index.html ) as oil was not naturally released (as far as we know) in quantities sufficient to have an effect of the required magnitude.
Point 10 – We can eliminate other pollution (atmospheric/terrestrial/oceanic) from industrial and general anthro sources, and probably smoke from fires etc.
So what’s left is the obvious question and there is no obvious answer. It all depends to what and to how much the climate is sensitive. But not being a total piker, here’s some thoughts.
External Forcings – I believe that cloud/albedo changes will eventually be shown to have a significant role. This is about the only thing that may have a strong enough influence to account for the MWP and LIA. Now whether it is Cosmic Rays or something else such as reduction in DMS and other hygroscopic nuclei as a consequence of sensitivity to solar variability (see http://www.sciencemag.org/cgi/content/abstract/315/5811/506 ) remains to be seen.
Internal Forcings – I believe that tectonic changes will be shown to have an effect. There is a recent increase in earthquakes globally that I don’t think can be attributed to better measurements – especially the nearly 100% increase in the 2.0 – 5.9 magnitude earthquakes since 2000.
Check out these sites to get an idea of how the earthquakes have increased since 1990.
http://neic.usgs.gov/neis/eqlists/eqstats.html
http://neic.usgs.gov/neis/eqlists/info_1990s.html
This is a link to the 1980’s – however you’ll have to use the “wayback machine” as it no longer exists.
http://neic.usgs.gov/neis/eqlists/1980s.html
The last thing I want to highlight is the possibility of sub-surface volcanic activity as a climate variability driver (see http://environment.newscientist.com/article/dn12218-thousand-of-new-volcanoes-revealed-beneath-the-waves.html ). Now if there are “millions of undersea volcanoes, then if because of tectonic stress as above etc some decide to pop simultaneously, the ocean surface will warm slightly etc etc. which may be an understated / not understood factor in today’s warming and may have been present in the past.
As always, happy to enter into any serious discussion…
cheers
Arnost
Luke,
WRT to the GCMs recreating / understanding past climates, no I can’t show that GCMs were parametrised on the Hockey Stick. But by the same token, you can’t show a GCM that recreated the MWP and LIA with the magnitudes that’s shown by Loehle (and probably Moberg as well). Is there one that you know of and has it been used to predict future climates?
And so where are the drivers of climate to support Loehle – we seem to have a problem don’t we. All very unsatisfactory.
Chapter 6 of the 4AR goes all through in some detail. Figs 6.13 and 6.14 etc.
TREE RINGS DON’T INDICATE PAST TEMPERATURES
The Daily Telegraph, 23 November 2007
http://my.telegraph.co.uk/reasonmclucus/november_2007/tree_rings_don_t_indicate_past_temperatures.htm
Reason McLucus
One of the reasons I doubt that the climatologists who talk of global warming are scientists is the claim that tree rings provide precise evidence of past average temperatures that can be compared to thermometer measured temperatures.
Craig Loehle has published a study in [Energy & Environment] indicating that trees rings are not reliable for determining past temperatures. Loehle focused on the Medieval Warm Period (MWP) (1000 – 1400) which is not shown in tree rings, but is apparent using other so-called proxies.
Loehle notes that tree ring width respond to temperature in an inverse parabolic manner to temperature with growth increasing up to some optimal temperature and then decreasing with further temperature increases. In other words narrower rings could actually indicate higher temperature rather than lower temperature. Loehle suggests that higher evaporation rates at the higher temperatures may slow growth. Tree growth responds to changes in the amount of CO2 in the atmosphere by increasing growth as CO2 increases.
Loehle cites a satellite survey covering 1982 to 2003 that indicated in tundra areas photosynthetic activity increased, but such activity decreased in forested areas, possibly because of the density of trees. As density increases individual trees may receive less sunlight and have less energy available for growth.
Loehle doesn’t examine the fact that trees reduce heating of the air by converting solar radiation into the chemical bonds of the carbon molecules deposited in the trunk. The greater the tree growth the lower the temperature if solar radiation remains constant.
Same AR4 chapter
I noted the backhand hat-tip to Hubert Lamb – who concluded that ‘High Medieval’ temperatures were probably 1.0°C to 2.0°C above early 20th-century levels at various European locations – i.e. :
“Much of the evidence used by Lamb was drawn from a very diverse mixture of sources such as historical information, evidence of treeline and vegetation changes, or records of the cultivation of cereals and vines. He also drew inferences from very preliminary analyses of some Greenland ice core data and European tree ring records. Much of this evidence was difficult to interpret in terms of accurate quantitative temperature influences.”
So it is safe to ignore. “However, the evidence is not sufficient to support a conclusion that hemispheric mean temperatures were as warm, or the extent of warm regions as expansive, as those in the 20th century as a whole, during any period in medieval times (Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briffa, 2006).”
But no mention of Moberg 2005… though I note that the MSH2005 (Moberg) reconstruction – the blue line in the spaghetti graph in Box 6.4 fig 1 is included and stands out. I think that is generally acknowledged that this reconstruction is heavilly influenced by the Arabian Sea G.Bulloides proxy. Without it the reconstruction would be closer to that of Loehle.
And there goes the MWP…
Yes yes Arnost all very interesting – but what’s driving your warming and cooling?
IPCC AR4 final, final, final, final summary:
“Paleoclimate information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1300 years.”
And this paleoclimate information is principally based on Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briffa, 2006. etc all depending on the MBH BCP PC1.
Luke – Hopefully Paul will release my spammed post that will partly address your “but what’s driving your warming and cooling” question.
Maybe repost the bugger but no more than 3 http:’s – strip the prefix off the 4th and subsequent links. More than 3 web urls revs up the blog nanny and post is sin-binned.
Paul – is that a “tuneable” parameter – this is a science based site surely. Even though many scowl “too much link link”. Although conversely ferals like James go “gimme gimme linkies then do a runner”.
Arnost is on a roll here and need to get published !
Another Arnost post released from the spam filter!
Thanks Arnost
Well we have a problem if Loehle is right
– either – the models are wrong, the proxies are wrong, the proxies aren’t global, there’s something we don’t know about.
Need to formally eliminate Ruddiman and orbitals http://en.wikipedia.org/wiki/William_Ruddiman
and http://www.nature.com/news/2006/061127/full/news061127-8.html
Do we know why Loehle was not accepted in other journal – proxies? analysis? any clue.
Loehle made a post on CA saying that GRL sent it back unreviewed because they were “tired of seeing reconstructions”. From Craig Loehle post 6 on the first CA thread for this. Read into this what you want…
Good thing to table Ruddiman – but I suspect that this sort of influence was not material.
So what do we agree / disagee on?
I suggest we rank and weight influences – i.e. factor X contributed 10% of the warming etc and see what we get to.
Paul – “One of the reasons I doubt that the climatologists who talk of global warming are scientists is the claim that tree rings provide precise evidence of past average temperatures that can be compared to thermometer measured temperatures.”
Please post the reference where a scientist has said such a thing. Either that or retract it.
This has gone too far. Proxies, accurate or otherwise, have NOTHING to do with the science of the enhanced greenhouse effect and/or the subsequent affects of the enhanced greenhouse effect warming on the Earths climate.
Scientists are very well aware of the inaccuracy in the proxies and this is the reason that PCA analysis was used in the first place.
As far as I can see Loehle has improperly weighted the different proxies. In this McIntyre has done science a disservice. Because of the undue attention placed on statistical techniques and selection of proxies a flawed and incomplete paper has resulted that is unpublishable. This is McIntyre’s legacy and science is much the worse for it.
BTW no-one has yet explained why this graph attributed to Roy Spencer stops at the year 2000. HadCRUT3 continues to 2006 at least and would show warming of +0.422° equal to the MWP range in this diagram.
Well you need to put Loehle’s graph on 6.13
Assuming it doesn’t line up well you have a problem in that the drivers don’t seem to be there.
6.13 gives a modest solar boost to the MWP.
Probably should recheck for orbital driver from original Laskar paper.
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26A…270..522L&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
What’s our evidence for a global LIA.
Ender I think Roy’s black line was a smoothed 30 year average so you last data point in a smoothing would have to be 15 years before the end of the series – half of 30 (and start 15 years in for same reason). Smoothed series can’t run the full length of the original series exactly.
However his scale doesn’t make sense – talks about 2007 but graph only runs to 2000. Suspect he’s messed up axes or something.
Paul?
I really don’t have the time right now to play – but another thing that has to be added to the mix is response times. We can have an immediate effect – say warimg due to CO2, but we can also have delayed response times – say cooling due to an increase in CRs after a 12-18 month response to solar variance system.
There are two key points here
One is the thermohaline circualtion. That latest paper by Stott showed a hunderds of years delay between solar forcing and the CO2 response – neatly tying in with the VostoL/Anatarctic CO2 lag behind temperature.
The other is biological response. Over the last couple of decades research has shown a decrease in surface phytoplankton – leading to a lower absorption of CO2. It has also been shown that phytoplankton seeks lower depths to escaper from UV.
A hypothesis playing at the back of my mind is that there may be an evolutionary factor at play here as well – the plankton is stressed as a consequence of an innitialy warmer / stronger UV environment and absorbs less CO2 leading to the feedback observed icecores, but then adapts and cycles all the CO2 out of the atmosphere.
I’m sure there are other complex relationships of this ilk that have a role to play.
cheers
Arnost
Ender, take a step back, chill out and have a read of this – it’s a nice manual on how to spin-doctor your postion better:
http://www.countryguardian.net/warm_words.pdf
What’s our evidence for the LIA?
The first and foremost is the CET. http://hadobs.metoffice.com/hadcet/cetml1659on.dat which shows that the temps in the late 17th century were 1 – 1.5C cooler than the 20th Century. This is supported with records such as ice on the Thames in the Year of the Great Frost in 1683.
Then there are paleoproxies that also postulate this to be global. (Note that Eli Rabbet atleast acknowledged the global extent but downplayed its magniture in his “Very Little Ice Age” thread.)
From below:
http://www.grisda.org/origins/10051.htm
“In conclusion there is ample evidence that a significant cooling occurred for several centuries starting around 1450 AD. This cooling caused significant changes in the distribution of plant and animal life and in the way man responded to the environment.”
It is a good starter – sumarises and draws heavily on the wide ranging analises of Hubert Lamb – who I admittedly have not read, but who even in AR4 was acknowledged:
“Much of the evidence used by Lamb was drawn from a very diverse mixture of sources such as historical information, evidence of treeline and vegetation changes, or records of the cultivation of cereals and vines. He also drew inferences from very preliminary analyses of some Greenland ice core data and European tree ring records.”
cheers
Arnost
I can’t believe you guys are still hung up in this nonsense. Tree rings, growth rings proxies from whatever, one would still need vast numbers of measurements from the past to come up with a graph like the one above. Also its only in recent times that we can say with any certainty our direct readings from instrument systems have the sort of accuracy required to trace global temperature changes including warming.
Back to basics: We need a handy zero reference, say ice water and a range check such as boiling point. Immediately we must know pressure and so on. Lets say altitude affects growth on land as does depth in the marine environment. Sea shells and tree rings have to be calibrated to the standard at sea level. If we can find ancient temperatures this way we can also find ancient sea levels in the same data.
On my desk is an ancient Brannan London v Cumberland clinical thermometer in a chromed tubular case with a range 95-110 and a generous 25 x graduation/deg (one in seventy five). Averages for Man, Cat, Pig and Fowl are clearly indicated. I wonder; can you guys work backwards to more ancient times with this instrument and a piece of wood, shin bone or coral?
Your typical linear temperature recorder was good for plus or minus one degree C in the range 0-100 C over the post ww2 period, (50 years) scientific instruments weren’t much better and standards were rarely brought out into sunlight.
Here we are discussing something much finer than the thickness of a pen trolling over 2000 years. But its dreamed up through various filters from some very imaginative data sets considering the difficulties we would have defining your average temperature for all domestic cats on a global basis.
There is no accounting for other parameters like pressure, time lags or phase shift in these sweet decadal outputs, yet we know from current experience that rapid response to temperature change can be seen at sea level at the margins of sea ice.
Arnost: how many specimens were examined to produce the evidence for the LIA in your link above?
Arnost – “Ender, take a step back, chill out and have a read of this – it’s a nice manual on how to spin-doctor your postion better:”
It is not a question of spin doctoring – this is basic science we are talking about. There is no need to spin doctor the Enhanced Greenhouse Effect – that is solid basic science.
The resulting climate change is much less certain however there exists a significant risk that climate change will result in changes that disadvantage some populations of both humans and animals.
To mitigate this risk we need to reduce the causing factors of THIS warming event. There is nothing we can do about the MWP or the LIA so there is very little point banging on about it. There was no conspiracy to hide past warming or cooling events – in fact many scientists spent hundreds of man years of effort to find out about past climate by drilling huge ice cores. If there was a conspiracy to bury past climate events would it not have suppressed the 100 000 years or so of past up and down temperatures?
In retrospect it probably was unfortunate that the TAR included MBH99 as it was a preliminary go at resolving proxies and it gave such a wide field for sowing doubt. The follow up studies showed that MBH99 was essentially correct however that has been lost in the noise from Climate Audit.
It does not really matter what temperature the MWP or the LIA was and splitting hairs down to 10ths of a degree where no such precision exists in either tree ring or O18 proxies is just plain stupid.
Even if you categorically proved that the MWP was global and warmer than present you still have achieved nothing. That is because you offer no causes for either the MWP or the LIA. This is also because the people so adament about the MWP usually are not working scientists and are not really doing original science. They are just picking apart others work. The only way that the MWP could relate to the present is if you found the cause of it and linked it to something happening today that has a greater forcing than greenhouse gases and land use changes. For this you will need real research not poring over statistics.
The following is a comparison between the CET (grey) and Loehle (Blue). The CET is represented as an anomaly to 1961-1990 and the trend line is smoothed on a 30 year roling average – same as Loehle.
http://i10.tinypic.com/73ezq4z.jpg
Pretty close realy given we are looking a a global av versus a local one.
C’mon Anost: I still see a dog’s breakfast in the raw. up Take CET,1950-1960 see 2 degrees change downwards and that’s the nonsense which is against the upwards trend in R/L
Ender
“There is no need to spin doctor the Enhanced Greenhouse Effect – that is solid basic science.”
I think that falls under:
“Much of the noise in the climate change discourse comes from argument and counter-argument, and it is our recommendation that, at least for popular communications, interested agencies now need to treat the argument as having been won. This means simply behaving as if climate change exists and is real, and that
individual actions are effective. This must be done by stepping away from the ‘advocates debate’ described earlier, rather than by stating and re-stating these things as fact.”
Pg 25 of the article I liked earlier…
OK, I tried very hard to open up a rational debate here, but I see that it’s not working. So I concede… You have won.
BUT – since you have won and this is my second last post here – your quote:
“The only way that the MWP could relate to the present is if you found the cause of it and linked it to something happening today that has a greater forcing than greenhouse gases and land use changes.”
If I may be as bold to suggest – now you are thinking and opening your mind – please keep it up.
cheers
Arnost
Today, Australia has made a decision. The Libs are out. The new government (and I wish it well) has committed itself to ratify the Kyoto agreement and so we can expect that this will happen.
I have had LOTS of vino and therefore am tempted to give voice to my true feelings – the “in vino veritas” moment so to speak. So if the following is too long winded – I apologise.
My name really is Arnošt – I grew up in what is now the Czech Republic under a Communist regime before coming to Oz after the “Prague Spring”. I have seen the worst that Man can do to him/herself. My best friend’s dad “disappeared”. I have seen history rewritten, seen peoples faces erased from historical photos and seen televised mock trials ending in executions. I therefore have a bias against socialism and history revisionism. I also have bad genes. My maternal grandfather was executed by the Germans for subversive activities – he’s actually a bit of a hero – so, like him I tend to fight for what is RIGHT regardless of the consequences. (Got streets etc named after him in Prague – and his name is actually on that WW2 wall in Brissie). But I digress.
I would like all the readers of this post to think about the significance of how spin-doctoring can beat reason. Case in point – the Libs created 400,000 jobs with their “Work Choices” policy and, as a consequence of the unions spin-doctoring of what should have been a positive, “Work Choices” is probably what cost the Libs the government. So doing something right is trumped by good PR. Spin-doctoring has now beaten reason in the climate change debate…(please read this carefully if you have any doubts that there is not a spin-doctoring campaign http://www.countryguardian.net/warm_words.pdf . There also is a component of history revisionism – i.e. the “Get rid of the MWP” piece…
I see Kyoto as the pinnacle of this – and like my grandfather, I try to do that what I think is right. As every long time reader of this blog knows, I think that Kyoto is about worst dumb fck idea that anyone has EVER come out with. It is driven by a socialist agenda with the aim of a global redistribution of wealth and fck the climate. (And I have tried very hard to make people think about this).
A confession – my vocation is finance and specifically pricing of complex financial instruments. The only reason I got involved in climate change pros and cons was to get a leg up on the competition – understanding the “real” influences, factors and risks associated. And given the next big thing is pricing carbon derivatives, pricing the risk accurately is what my game is all about.
Bottom line, with the change of govt and the ratification of Kyoto, my role now changes and sorry, I can’t be “officially” involved in this debate anymore. (Maybe I can have a Phil Done clone here on the odd occasion?). My new role now will be to make a motza out of the converted faithful. SJT and Ender look out :).
So – I wish to thank a lot of contributors that made this blog so interesting. I have to single out the pseudonymous Luke, though you can get a bit emotional at times, I have truly come to respect you. I also have a soft spot for Motty… you know so much about the country – always providing an interesting perspective (but can you please keep the to-and fro with Luke humorous and not antagonistic? You too Luke!). And I still want to get my gnome to do a joint paper with Davey’s gnome on a few pet topics. Ann N – you are wonderful, and though I don’t contribute to your posts, please keep them up – I am a fanatic scuba diver and love the oceanic environment. Neil, I also love your posts on the critters (and by the way I have bush-bashed the Cooper Creek wilderness up to the falls and back). When I lived in East Africa, I used to keep praying mantises as pets… If the dice fell the other way, I probably would have ended up as an entomologist – hat tip to Jen. And keep up the posts Paul.
There are obviously lots of people that I have missed in acknowledging and I apologise that I have not singled you out – but thank you for the interesting posts that have in lots of cases made me take a step back and have a deeper think. To all the lurkers, please don’t be scared to contribute – it’s the divergence of opinion that advances general knowledge (would you believe that I was scared to post here at one stage…!)
So today it’s not cheers… but it’s GOODBYE.
Live long and prosper – and this extends to everyone.
Arnošt
Ender invites speculation on the causes of the MWP and LIA.
No one knows for certain the cause or causes of the current warm patch (not even the IPCC), let alone past fluctuations.
As for the ‘Enhanced Greenhouse Effect’ and resulting climate change, aren’t we ‘begging the question’ again?
The point is that the recent warming appears to be well within historical precedents and, if anything, life on Earth (including mankind) was largely unaffected or maybe even benefited.
I suggest that climate scientists are about as close to an accurate model of the Earth’s climate as Ptolemy was with his ‘crystal spheres’ to a model of the solar system.
I think the ‘activist’ scientists will eventually be scorned and excoriated by History for what they have knowingly and enthusiastically unleashed (many others will be quietly forgotten for their cowardice and silence) but it is not only a scientific question.
It is as much a philosophical, political and economic question as a well.
“was largely unaffected or maybe even benefited” – jeeez – well of course – we’re only just beginning. Actually chrisgo many are stunned with rapidity that changes are developing already.
“Wait for it !” as they say on parade.
Most “active scientists” really wouldn’t have a clue. How domain experts are there really? Have you yourself even read the 4AR – I bet not ….
Arnost, you will be missed! Good luck in your new activities. You can feel quite free to make money out of AGW since you have worked so hard to bring a touch of perspective to the debate!
All the best, Arnost.
Toby
Chrisgo – “No one knows for certain the cause or causes of the current warm patch (not even the IPCC), let alone past fluctuations.”
Ahhhh no – it its pretty certain this warming event is caused by the elephant in the room – human greenhouse emissions and land use changes.
“As for the ‘Enhanced Greenhouse Effect’ and resulting climate change, aren’t we ‘begging the question’ again?”
No – the enhanced greenhouse effect is the most likely cause of recent warming – how is this begging the question?
“The point is that the recent warming appears to be well within historical precedents and, if anything, life on Earth (including mankind) was largely unaffected or maybe even benefited.”
How would you know this? Only the people that benefited left any records. You have no idea of how many people lost out. There were also a lot fewer people in past thermal events.
“I suggest that climate scientists are about as close to an accurate model of the Earth’s climate as Ptolemy was with his ‘crystal spheres’ to a model of the solar system.”
Again how would you know this? How many computer models have you done to give you the knowledge to make this statement?
Ptolemy’s model of the solar system was based on a false assumption of the Earth being the centre of the solar system. We now know this to be untrue. While there is always the possibility, we are pretty sure that there is not any similar fundamental flaw in the science of the climate.
Also Ptolemy’s model at least was something. Remember finding and explaining problems with it lead to Copernicus and the current model of the solar system. Right at the moment there is no-one amongst the skeptics that is doing the same work as Copernicus, they are just finding holes in the statistical treatment of the crystal spheres.
Unlike some anonymous posters on sites as this, I’m not pretending to have any training or expertise in any branch of science, I’m simply an interested bystander.
The LIA and by implication, the preceding MWP have been a well accepted historic facts for years which makes the blithe acceptance of the Mann-Bradley-Hughs “hockey stick curve” by the IPCC and others who should know better, puzzling to say the least.
Ender, to baldly state that the ‘Enhanced Greenhouse Effect’ is the most likely cause of recent warming (i.e AGW) in a discussion as to whether the ‘Enhanced Greenhouse Effect’ is the most likely cause of recent warming is just that, begging the question.
May I (not so briefly) quote from “A DIstant Mirror’ by Barbara Tuchman, a very popular and readable account of the 14th century which is just on 30 years old i.e. written well before the climate change of the period in Europe was ‘controversial’:
‘When the last of the Coucys was born, his country (France) was supreme but his century was already in trouble. A physical chill settled on the 14th century at its very start, initiating the miseries to come. The Baltic Sea froze over twice, in 1303 and 1306-07; years followed of unseasonable cold, storms and rains, and a rise in the level of the Caspian Sea. Contemporaries could not know it was the onset of what has since been recognized as the Little Ice Age, caused by an advance of polar and alpine glaciers and lasting until about 1700. Nor were they yet aware that, owing to the climate change, communication with Greenland was gradually being lost, that the Norse settlements there were being extinguished, that cultivation of grain was disappearing from Iceland and being severely reduced in Scandinavia. But they could feel the colder weather, and marked with fear its result: a shorter growing season.”
There follows a lengthy but beautifully written account of the fall from a period of bounty, population growth and economic growth in Europe into famine, disease, war and misery. It was not the preceding warmth that caused these horrors, but the cold.
“The elephant in the room ……is an English idiom for an obvious truth that is being ignored. It is based on the idea that an elephant in a small room would be impossible to overlook” (Wiki) – to apply the expression to AGW aint exactly apposite.
No of course I have not constructed any computer models (except my house renovation).
Indeed Ptolemy’s model was based on a false assumption – precisely my point.
Chrisgo, sadly it does not matter how much common sense you try to bring to the subject, you will be met with the same comments about the immense amount of scientific evidence confirming our pending destruction of the planet if we do not rapidly curb our co2 emissions.
How dare you suggest that because it has been hotter in our recent past, that the current warming may not be a consequence of humans! And heaven help us if you suggested that the warming from 1910-1940 is similar to the warming from 1975-1995. It would be even more unreasonable of you to mention that despite the continued increase in co2 temperatures have not risen above the 1998 levels!
Lets sign Kyoto, cos its gonna save the world, and when we get sued for damages for not cutting emissions enough, we can help China build some more of its coal fired power plants. Then they can make all the aluminium the world requires, along with other materials that are high in energy use, by burning more of their dirty coal.
It is quite possible that humans are causing the current warming, but until politicians and and the vast majority of AGW proponents at least consider nuclear as an option, I think its more likely that it is a religion.
How precisely are we going to stop emissions anyway without doing serious damage to the worlds economy and thereby preventing those in third world poverty trying to claw their way out?….after all a barrel of oil is about 5 times higher today than it was 5 years ago, and yet our emmisions keep climbing……..SO how will a tax or a cap and trade scheme actually solve the issue unless we force the price of oil to extraordinary levels? ( I know it will make traders a load of money….and guys like Arnost!….best of luck with it Arnost!)
Toby you’re a science and policy genius. What a quality analysis. The depth of your analysis and science understanding is simply devastating.
Arnost may find that if he thinks traders might make a lot of money they also stand to lose lots of money for non-quality products. Or products that lose their carbon – it’s called liability.
You guys would have done well in Dickensian times saying the world would end if air quality was improved.
Arnost, let me thank you for providing us with a good example of the quality of minds that are at work in the places where it actually counts. As you may have guessed, many people go through life with no exposure to such influences so your time, “down here on a visit” was well spent.
Go forth, be fruitful, and multiply the numbers.
I think I owe everyone a very sincere apology.
Though what I wrote is mostly true, they way I posted, it was in reality a major alcohol fuelled dummy spit of the highest quality. Prima Donna behaviour at it’s finest. I am now very contrite and if I could, I would very much like to take a lot of what I said back.
I would like to thank Toby and Ian for what you said above (good pun Ian). This to a certain extent reinforces the stupidity of the post in that I have now lost credibility. But that’s life and unless you take responsibility for your actions (though consuming half a cask of wine may get me off in court of law on an issue where no blood was shed) it does not in any way lead to personal improvement. Live and learn.
So again – Sorry.
I work in an environment where EVERYTHING is monitored. The fact that I have been blogging during work time, I’m sure, has not gone unnoticed. However – if push comes to shove – I can always use the excuse that this was “research”. So in reality, with the election of the Labor government – nothing really has changed. Discussions of this topic are important and – given what my grandfather did – I would fail myself if I did not follow through. He did because he thought it right. If I’m out on my ar$e tomorrow – that is life and I did what I thought was right.
So!
Luke is not going to get a free ride…
“If he thinks traders might make a lot of money they also stand to lose lots of money for non-quality products…”
Quite possibly – but the money I lose will be gained by another trader. The punter on the end will gain his retail margin at best and wear the full loss at worst. And that is reality – the market will end up the better off.
Ender is not going to get a free ride…
“Right at the moment there is no-one amongst the skeptics that is doing the same work as Copernicus, they are just finding holes in the statistical treatment of the crystal spheres…”
If you don’t know it’s broke you can’t fix it. And if you’re told it’s not broke even when it is that’s religion. “No one expects the Spanish Inquisition” sketch comes to mind. (Good point crisgo).
I have had a few personal exchanges with Luke. For those that may not have guessed, I do correspond with Luke regularly. Though we don’t agree on a few issues : ) I have the highest respect for him. I would like to thank him for giving me LOTS of reason to question my “beliefs” and so better my understanding. I was going to send him the following. But as it expands on a couple of good points just raised by Toby, I thought it worthwhile to share: (I have edited it a bit to put previous comments from [Luke] to give better continuity) – I hope he doesn’t mind…
Thanks Luke…
Luke:
[Saturday was a referendum on Work Choices – the analysis coming is that that cost them most of the losses.]
I guess that Work Choices was that which gave Labor such a large majority – deep down I sorta knew that the day had come. There were too many negatives around, drought, interest rises, crap hospitals, schools, transport and and and. People being what they now are don’t blame themselves, i.e. if you’re in supposedly in the driver’s seat – you get the blame.
Work Choices was not a bad policy – just sold wrong… or rather not sold at all but “imposed”. And this was probably what pissed the voters off the most. They should have had it as a cornerstone of an election and advertised before it was introduced in the same way that the GST was. The fools introduced it as a fait accompli and by the time they responded to the negative union advertising and winging about “dictatorial” power – it was too late. Everyone “knew” it was bad.
Luke:
[Spoken like a highly mobile well-educated professional “In a high employment environment, if the boss sucks – move on and go elsewhere.” … It’s not that simple for a lot of people. Jobs have been created but a lot of them are crap casual hamburger-flipper jobs. Wait till your kids are entering the workforce – your views change on how they are being treated.]
I appreciate that moving on is not simple for a lot of people – you are right in that. But the fundamental differences between “professionals” and the salaried employee is that the professional has something that is marketable other than on the job experience. But you also have to recognize that in the future there will be no hamburger-flipper jobs – the hamburger flipping will be automated and we will all be professionals of one sort or another. We will either: design better hamburger flippers, operate hamburger flippers or maintain hamburger flippers – with a bit of management and politics. So we have to take responsibility for the future and expect a little sacrifice (i.e. evening study) to ensure a better lifestyle.
I intend to drum into my kids heads that what my parents drummed into mine – the classic anti socialist spiel – “they can take away your job, your house, your social status and your freedom, but short of killing you, they can’t take away what you have inside your head”. I was constantly challenged to think and to (if I didn’t understand something) learn. And as this has stood me in good stead – and it should do the same for them. I intend to ensure that ultimately they are responsible for and to themselves.
Coming from a commie country, I am sensitive the pervasive growth of the socialist ethos – and not only here but in the rest of the western world. And being of an austrian lean as well, this to me is fundamentally wrong. I see more resources spent on politically massaging a situation rather than fixing it, I see a culture of denial of personal responsibility growing ever more pervasive, and I see (most worryingly) rigorous enforcement of politically correct groupthink. Sorry, but though I agree that the Liberals are now a bunch of no hope amateurs – I think that Labor is far far worse.
Every State is Labor run, and in a period of prosperity for all bar the poor farmers in the drought, every State has gone backward over the last 5-10 years. Labor is reactionary in its approach. They will not drive through tough changes that are required to get Australia into the 21st century – they are all about consensus, ensuring the status-quo is maintained, and massaging the media to best effect so that they “seem” to be doing something. (And apart from the drought and maybe interest rises, they are the ones really responsible for the crap hospitals, schools, transport and and and). No progress is dangerous – no business, company, or nation can afford to remain unchanged for very long in the modern world – status quo => out of business and impoverishment.
Luke:
[Rudd has to be very careful on carbon – if price of power and fuel goes through the roof – the populace with revolt as they have on Work Choices. He’ll be gone ! Rudd will also have to deliver on his agenda and prove for once, a Labor government can get the balance right. Not just do the reform bit and bugger the economy.]
I would really like to see a Labor leader take action and damn the consequences. I’ll have a bet – this term will achieve nothing except blaming the past Lib government for any bad turnarounds – including them stuffing up industrial relations again when they dismantle Work Choices. And they will be minimum three terms regardless of how little else they do. They have inherited a very strong national economy that’s doing well without the need for any intervention and the drought’s about to break in the east – we are going to have a La Nina well into next year, and I suspect possibly into 2009. There will be nothing that can be blamed on them until they start to borrow again to fund the consensus, healing and other bureaucratic excesses to spin-doctor their lack of progress.
So there – the reason I’m so unhappy is that it now appears that the Libs will be consigned to the dustbin of history. If they hung around a bit more they could have lifted the quality of the State parties. This now ain’t going to happen – there’s a good chance they will fall apart. They are going to lose talent – I mean let’s face it who would want to go into politics at the salary level that’s offered now given that you lose all privacy, you get ridiculed every day, and you have so little freedom to act. I really think that we are entering (and funnily enough as Karl Marx predicted) into a long term period of “transitional socialism”. But this is happening before we have sufficient wealth for EVERYONE. If we strip all the Packers and Murdochs of their wealth – we may all get a new Plasma TV. But we will loose the accumulated capital that they use to invest and create more wealth – so the “Mr. Fusion” powered De Lorean will be out of our reach.
This is also my main beef with the IPCC consensus / Kyoto push. It is a socialist instrument aimed at re-distribution of wealth before we have sufficient wealth for everyone.
And I don’t really care if the scientists are wrong or right – the reactionary socialist approach is not going to help the world if temperatures change. And change they will one way or another – it’s stupidity to think that the earth is ALWAYS going to be within a fraction of a degree of today’s temps. We need action – driven by leadership and vision. If the IPCC said they would ask the participating countries to impose an additional pigouvian tax and that they would put this into a Climate Change fund which will be used to pay for alternate energy research and adaptation etc – we probably would not be having this conversation. It’s not that effing difficult – here’s an aspirational goal and this is how we are going to achieve it – and guess what, if the scientist’s are wrong we have funded fusion etc etc all of which you now get freely rather than having to pay Exxon for the rights and oh yes, here’s your change. By having a quasi-market carbon trading scheme the money is firstly diluted by the likes of George Soros who will take the odd billion or two, and secondly, will go to the likes of Ugandas and Indonesia of the world and ultimately only used to line the pockets of the Amins and Suhartos.
And if this is too cynical and miraculously the wealth is equitably distributed, then this will allow everyone to buy a Mix-Master (but not the electricity required to run it)!
And regardless of which of the previous two occurs, the west will have lost the resources that it could have otherwise used to invest in fusion research etc, and the ability to give away a billion dollars like Australia did when the 2004 Tsunami happened. Achieves sweet FA – and people are brainwashed to the fact that when we sign Kyoto the temperatures will miraculously drop.
Do you know why this year is so warm as per GISS and NCDC – esp when there’s record rainfall, cold snaps etc all over the place? Because sea water is warmer than ice. The anomaly in the Arctic where all the record ice loss occurred drove the last six months high global averages. This will not happen next year as the ice will recover somewhat. The sea ice is already within 100k of Iceland and there’s a big cold pool in the Bering Straight (which there was not last year) and the negative PDO will support this.
Here’s a prediction, Rudd signs Kyoto and 2008 and 2009 will be cooler. See Kyoto worked…! I wonder if he’ll take credit.
Luke:
[Unlike yourself I would blame 100% of the recent warming on AGW – I see zero evidence for anything else. As for MWP and LIA – doesn’t add up ! Something is missing.] (I suggested 30% AGW)
And I’m really surprised that you think 100%. There have been at least three episodes in this interglacial where the temperatures were warmer than today. Even if we agree on just the Climactic Optimum 8,000 years ago – you have to accept that it is in the realms of possibility that the cause of this one may not be all AGW. 100% implies you reject any such possibility. Actually I’m a bit disappointed in that – especially when you say that something is missing.
And remember – this is an “interglacial” i.e. we are still in an ice age – the “normal” temperature of the world over millions of years is usually LOTS higher.
Still sulking
Arnost
chrisgo – “Ender, to baldly state that the ‘Enhanced Greenhouse Effect’ is the most likely cause of recent warming (i.e AGW) in a discussion as to whether the ‘Enhanced Greenhouse Effect’ is the most likely cause of recent warming is just that, begging the question.”
Here is the definition of begging the question:
“Stephen Barker explains the fallacy in The Elements of Logic: “If the premises are related to the conclusion in such an intimate way that the speaker and listeners could not have less reason to doubt the premise than they have to doubt the conclusion, then the argument is worthless as a proof, even though the link between premises and conclusion may have the most cast-iron rigor”.[1] In other words, the argument fails to prove anything because it applies what it is supposed to prove as fact.”
Given that recent warming is an observed fact then we have determined that:
1. CO2 and CH4 etc are greenhouse gases that trap long wave radiation
2. Humans activities emit these gases.
3. These gases have been measured to be increasing in concentration (CO2) or have increased and are now stable (CH4).
4. The resulting forcing from these when added up are in the right order of magnitude to account for the recent warming.
5. Experiments run in computer models do confirm that forcings of this magnitude could cause some degree of climate change.
So where is begging the question here chrisgo?
Can you lay out your evidence trail for a rival theory to account for recent warming?
“May I (not so briefly) quote from “A DIstant Mirror’ by Barbara Tuchman, a very popular and readable account of the 14th century which is just on 30 years old i.e. written well before the climate change of the period in Europe was ‘controversial’:”
Not really as this is anecdotal evidence that is much less reliable than the tree ring proxies that are held in such disdain. Also, even if it reliable, are these accounts from all over the world or just Europe? Most of the the world was not ‘discovered’ by record keeping Europeans so you still have no idea of the winners and losers.
“Indeed Ptolemy’s model was based on a false assumption – precisely my point.”
So what is the false assumption behind AGW??? Can you prove it is false???????
Ender
“The resulting forcing from these (CO2 and CH4) when added up are in the right order of magnitude to account for the recent warming”
No they are not – A doubling of CO2 will result in a temp increase on the order of 1°C. So at most the observed increase in C02/CH4 could have at most caused 30% of the observed temperature increase so far.
Your logical argument supporting AGW therefore fails the reality test and is falsified. Therefore in turn it is logically proved false.
And anecdotal evidence – from MULTIPLE INDEPENDENT sources will on its own trump your “reliable tree ring proxies” any day – and more so when there are ice-core and other bore hole, polen, and vegetative movements also supporting the anecdotal evidence.
I just found this discussion, sorry for getting in late. My goal in keeping it very simple was so that no one could accuse me of slight of hand or cherry picking–though some still have made such accusations. Those defending my paper on this site have been 100% correct about my methods and the data, validating the clearness of my exposition. Please all keep in mind that I did a 30 year smoothing because if you overlay all the plots some of them have gaps (data not annual) so you can’t combine them without smoothing. It is not a “trick”. Overlaying the recent data as in the top graph is a little bit apples and oranges, since that is annual. In a smoothed plot the amplitudes will be lower because hot years average with cool years and you see only the long-term behavior.
Thank you for your contribution Craig – The fact that you only used 18 proxies is I think a significant defect in your work.
If I may suggest, visit ukweatherworld and have a look at the pinned thread seeking articles on the Climatctic Optimum – http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=5124&posts=60&start=1
You may find some papers there that will provide more data should you wish to expand your proxy series. Otherwise use the blog resources out there and see if you can do simmilar there or at CA and have a thread where papers with temperature calibrated records for the MWP and LIA can be linked. Will make your next paper so much better and your research deeper.
Keep up the work.
Arnost – where did CO2 double from – when?
As for “A doubling of CO2 will result in a temp increase on the order of 1°C.” – many would disagree.
As you know models don’t reproduce the 20th century temperature evolution without including all factors of solar, aerosols, volcanism and greenhouse.
We are left with a condundrum with Loehle’s paper in that the known paleo forcing proxies do not reproduce the Loehle warming graph. Why:
could be poor proxies, proxies not globally representative, paleo forcing proxies are wrong, GCMs are wrong, something we don’t understand.
I also haven’t seen any meaningful error bounds around the Loehle graph.
It’s all very unsatisfactory and we’re still not any more informed.
Ender
The other fatal flaw in your logic is that you make an assumption that there is NOTHING ELSE that can also explain the temperature increase in the last century.
There’s a new JGR paper out by Nicola Scafetta – “Phenomenological reconstructions of the solar signature in the Northern Hemisphere surface temperature records since 1600”
http://www.fel.duke.edu/~scafetta/pdf/2007JD008437.pdf
quote:
…
A phenomenological thermodynamic model is adopted to estimate the relative contribution of the solar-induced versus anthropogenic-added climate forcing during the industrial era. We compare different preindustrial temperature and solar data reconstruction scenarios since 1610. We argue that a realistic climate scenario is the one described by a large preindustrial secular variability (as the one shown by the paleoclimate temperature reconstruction by Moberg et al. (2005)) with the total solar irradiance experiencing low secular variability (as the one shown by Wang et al. (2005)). Under this scenario the Sun might have contributed up to approximately 50% (or more if ACRIM total solar irradiance satellite composite (Willson and Mordvinov, 2003) is implemented) of the observed global warming since 1900
…
It basically uses the Moberg 2005 reconstruction and looks to align the influence of the sun to this and then see what forcings this HYPOTHETICALLY implies for the modern period.
It would be interesting to see what would happen if this type modeling was also done using the Loehle reconstruction. The sun would likely contribute more than 50%…
Look – all the solar reconstructions are based on proxies that respond to solar wind and are calibrated to the modern geomagnetic indexes – i.e. the aa and ap index.
http://www.ngdc.noaa.gov/stp/GEOMAG/aastar.shtml
And even Lockwood admitted a couple of years ago that the last years of the 20th century had the highest solar / geomagnetic activity since records began.
“Experiments run in computer models do confirm that forcings of this magnitude could cause some degree of climate change”
Is it not possible that a) there is another response / feedback to solar activity that is not included in the models and b) these responses may not be instantaneous (as is modelled) but may have lags of many years /decades?
Your argument is again falsified on the basis that you did not eliminate other potential influences.
cheers
Arnost
Luke,
“Many would disagree” ONLY because they factor in a significant feedback from H20. Ender did not include reliance on this feedback in his logical thesis – so, as it is, it is falsified and needs to be improved / revised.
Arnost –
“It would be interesting to see what would happen if this type modeling was also done using the Loehle reconstruction. ” errr – nope the modelled answer would still be the same.
Arnost – “The other fatal flaw in your logic is that you make an assumption that there is NOTHING ELSE that can also explain the temperature increase in the last century.”
I or anyone else did no such thing. ALL forcings are considered. The solar forcing is there for all to see:
http://www.nap.edu/openbook.php?record_id=11175&page=29
and is about 0.3W/m^2.
I make no such assumption as the forcings have been measured pretty accurately. Do you have data or a reference that shows that the forcing are different?
Arnost – “No they are not – A doubling of CO2 will result in a temp increase on the order of 1°C. So at most the observed increase in C02/CH4 could have at most caused 30% of the observed temperature increase so far.”
You are confusing climate sensitivity with the actual heating effect of the radiative balance of the Earth being out by +4W/m^2. In response to this imbalance the Earth’s ocean/atmosphere will heat up to restore the radiative balance.
Climate sensitivity is an estimate of what would happen if CO2 was doubled. It ranges from a low of 1° to a more generally accepted figure of 1.5° to 4.5°.
In a radiative model the resultant forcing from summing the known forcings is of sufficient magnitude to account for recent warming – this has nothing do with estimates of climate sensitivity.
“I guess that Work Choices was that which gave Labor such a large majority – deep down I sorta knew that the day had come. There were too many negatives around, drought, interest rises, crap hospitals, schools, transport and and and. People being what they now are don’t blame themselves, i.e. if you’re in supposedly in the driver’s seat – you get the blame”
Arnost; something missing above and its called “arrogance”.
JH n co had it coming for a while and it’s called a quick “punch in the mouth”. Apart from the campaign of dirty tricks right up to election day there was all the put downs. Aussies won’t stand for someone taking advantage of a situation especially when it comes from a trumped up class structure. A fair go means “a fair go”
Note; I never said Ta Ta to Arnost after reckoning he’d be back soon enough.
Have a go mate its still a free country.
Craig: I’m still fascinated by your reckoning on this process. How much raw data was used up front in the original proxies?
INCOMING !!
http://www.realclimate.org/index.php?p=502
has to hurt !
Ender, to beg the question is to assume the point in dispute – to smuggle into the premise, the conclusion about to be deduced.
The anecdotal and archaeological evidence from many and varied sources of the MWP in Europe around the early 1300s is pretty compelling.
Archaeological evidence from Meso-America and South America certainly does not indicate that there were any losers there (being near or at the Equator anyway) and the Southern Hemisphere was sparsely populated anyway. It is interesting to note that one of the earliest settlements of New Zealand was in the area of modern Dunedin between 850 – 1100 AD.
Are you denying the existence of the MWP or do you simply find it an ‘inconvenient truth’ that must be “got rid of”?
You are convinced that most if not all of the recent warming is mostly or solely due to the additional greenhouse gases injected into the atmosphere by mankind in the last, say, 50 years thereby upsetting the natural balance.
You appear to reject any significant contributing factors like the sun.
You also appear to reject any beneficial effects that might flow from more atmospheric CO₂ or a warmer climate.
That’s all fine but if you are a trained and practicing scientist you must know that all alternative explanations for the observed events must be explored equally and I don’t believe you are even prepared to that.
I was not suggesting that there is a false assumption behind AGW.
I was suggesting that the computer models that purport to predict future temperatures have false assumptions written into them.
It is ridiculous to suggest that because the AGW hypothesis cannot be disproved, therefore it must be true – you must take me for a fool.
Time will tell.
….of climate change around the early 1300s…