Which Global Warming Skeptic Are You?

You forgot E, Tim:

We can't really know until we audit the quantities for ourselves, because it's likely that the volume measurments are influenced by biased scientists.

Best,

D

No Dano, it's the overhead charge the research agencies collect on grants that influences the results. You need to read CA more carefully.

Essex is on the Science committee for RPs upcoming "balanced" conference: http://climatesci.atmos.colostate.edu/2006/03/14/upcoming-climate-meeti…

Why has Tim not released the cream labels?
His failure to do so appears suspicious, to say the least, and casts doubt upon his results.
Aha! I see Australia has a Senate!
I'm gonna get my Senator to call all twelve of your Senators, and have one of them demand the full record of your cream purchases for the past three years, specifying the purpose and funding (with source and nature) for aforesaid purchases of cream.
We will expect your answer by last Thursday.

Sure, Bob. Suuuure.

Why don't we lookit...uh...er...

Saaaay, waiiiiit a minute! hey, Bob, that's sarcasm, right?

Haha. Got me. Good 'un! Had me goin' there! I was a little slow to notice that evidenceless assertion.

Haha!

Best,

D

I'm not sure you use the simplest explanation of their error here. The answer is much simpler:

the average temperature of a system is defined to be the total heat energy over the total heat capacity.

There's no possible argument that "total heat energy" and "total heat capacity" are well defined; for each quantity you combine both systems by sum.

The analogous argument is this: average cream proportion by mass = mass of cream in the system / mass of the system.

Each day I will post a picture of a scientist's freezer, containing a half-eaten carton of ice-cream. Each picture will prove scientists have been irresponsibly sampling the ice cream in question, hopelessly skewing the results of the experiment.

Once again, llewelly proves scientists are getting fat by skewing their results.

Proof! Proof!

D

D,

;)

Even the relatively shameless Ross McKitrick has become embarrassed by association with Essex over this stuff. As people would understand, it somewhat spoils the pose when the luminary you've relied upon for your debunkings and ridiculings of the state of science in somebody else's field turns out to have been a dummy of the first water. A dummy without the courage to now put his head back over the parapet with you when you've run out of places to hide from the critical attention you're receiving. McKitrick well deserves what he'll suffer "in the fullness of time" for the pomposity and presumptions of adequacy in that foolish book of theirs. "Cooler Heads"? They so wish. Of course in the short term there'll be no end of kudos in it for them - all of it from people they'll wind up hoping never to hear from again.

I have a hard time believing that McKitrick and/or Essex believe this stuff themselves. It seems more like propaganda written to target a layperson audience.

C'mon, Tim, please use a relevant analogy!

How bone-stupid do you have to be before you don't get cited as a leading dissident researcher any more?

Actually, D is OK, although A is better for many reasons, (see http://rabett.blogspot.com/2005_11_01_rabett_archive.html) as long as you use the Kelvin (absolute) temperature scale. The boys from Canada, used Celcius, which is a kindergarden error (OK, my kids are smarter than yours, and I don't have any). Radiative emission is proportional to T^4 ONLY if T is in Kelvin. The statement about kinetic energy is even worse. The square of the speed is linearly proportional to temperature, so you have to wonder what they were blathering about there, or maybe they are secretly arguing for a linear average.

My favorite comical quote in the book is this:
"Everyone agrees that some kind of averaging may help, but this idea is in itself not very helpful, even though unchaperoned averaging has been going on in the back allies (sic) for decades."

Forget the stupidity, the more I read the more these guys look like 17th century Puritans.

'My favorite comical quote in the book is this:
"Everyone agrees that some kind of averaging may help, but this idea is in itself not very helpful, even though unchaperoned averaging has been going on in the back allies (sic) for decades."'

Those who do not understand averages are destined to be below one.

Rabbett: you seem to be saying that you have to take averages in Kelvins. That can't be right; you get the same temperature no matter what scale you take the averages in.

Paul, what I am saying is that EXCEPT for the arithmetic averages you have to take the averages in Kelvin. This is totally true for the T^4 average that E&M advocate as being proportional to emission as expressed in the Stefan Boltzman law and for any average that you are claiming to be proportional to temperature.

And NO except for the arithmetic average you DON'T get the same answer no matter what the scale is, which is one darn good reason to use arithmetic averages. For example for a geometric average, if there are any zeros in the data, the average is zero, e.g. the geometric average of 0 100, 100, 100, 100 is zero.

** You can be REALLY pedantic in the following ways: For the T^4 average the zero of the scale MUST be O K, although the scale itself (the interval between degrees) can be arbitrary. The same thing would be true for an average that you want to be proportional to the total energy. If you don't use Kelvin, you will have to adjust the Boltzman constant and the Stefan-Boltzman constant appropriately. The physical reason for this choice of the zero point is that the energy and the emission will be zero at 0 K. If you don't understand this comment, you can safely ignore it.

To repeat, for the other types of averages (geometric, harmonic, etc.) to make sense there should not be any zeros or negative numbers, otherwise you get misleading results. See http://rabett.blogspot.com/2005_11_01_rabett_archive.html) for examples. The bit with the vector RMS average that E&M blather about is similar. You cannot call two vectors with the same magnitude the same. They can point in different directions.

But what does global warming mean for the Sydney Blogger's picnic this Saturday, Tim? Should we wear sunhats or raincoats? Inquiring minds want to know.

Good on you tigtog! I wonder if we should subscribe for a space ship attack on the sun manned by Tim and co and armed with the CO2 fire extinguisher I will offer for them to damp down the sun which is now revealed to be real source of rising GW.

Tim Curtin, tish and tosh and fie upon you for attempting to deflect attention from the serious matter of a Sydney blogmeet.

Take issue with GW arguments if you must, but please don't append my name anywhere near such stuff.

Now shoosh, or I will have to paste you with hamsters and elderberries.

Rabbett: I was thinking of the arithmetic average; it's true also of the median and mode, but of no other average. But that's the physically natural one so that's OK!

Eli has a closing paren included in the HTML for his page, so it comes up "Not Found" -- correct link is:
http://rabett.blogspot.com/2005_11_01_rabett_archive.html

Tim Lambert helpfully provided access to the paper by Hansen et al "GISS analysis of surface temperature change", which clearly he regards as one of those tablets brought down to Moses/Mohammed. If that article is Science, then I'm not a Dutchman, but quite possibly a bin empty.

Without being palpably dishonest, it is replete with special pleading. Yet again "global" means everywhere except North America, the Arctic, India , and China. With 3 of those 4 responsible for most CO2 production this is a little odd, n'est pas? But to be fair Hansen & co do admit that the urban heat island effect is significant and has not been fully accounted for (their Fig.3 shows that for Tokyo and Phoenix (Arizona) the urban effect eliminates any upward trend in temps). My own casual empiricism has shown that when my wife turns on our new air cons the temps in our garden rise dramatically, likewise at Canberra Airport where the new Science "park" has impacted on "THE" temps for Canberra reported to GISS. Time is short, but when "global" is defined by HANSEN et al to exclude North America (p.12), the North Pacific (p.17) the Middle East (p.17) India and China (p.17), what does the word "global" actually mean? More so when USA, India, and China are said to be the main sources of AGW/CO2 by the Grand Sufi of UNSW? But to be fair, Hansen et al admit (p.25) that "urban effects are non-negligible" (p.25, they could have added "and increasing in magnitude").

Mr. Curtin:

I commend you for your attempts to clean up the English Language. After you straighten up this global warming crowd could you please start on the stock market crowd. They always talk about a market going up but some of my stocks go down!!!

Likewise the weatherman says that it is raining but since I got the leak in my roof fixed there has been no rain in my living room!

Finally, while my wife says I am getting old I am sure that in fact some of my cells are actually fairly young so perhaps you could straighten her out.

Thanks in advance

John Cross

Timmy ululatingly tries to argue that the UHI has polluted the surface temperature record.

Timmy, you are, Galileo-like, the first to say this. Your mom must be very proud. Congratulations. No one has argued this before you and thus the text you cut-pasted typed hasn't been debunked before, certainly not here.

If you'll excuse me, I must go as I have to stifle a yawn arising from Timmy's trite argumentation.

D

I said A of course and I agree with the person earlier who said that heat capacity was the relevant analog for mass.

I think a more relevant complaint of EM on the temp averages would have to do with surface versus volume measurements, non-correction for different heat capacities of different surfaces, or even an argument over "what matters". I mean you could have the same surface average but with different distributions. Some distributions may have little impact because they don't melt the ice sheets (or do).

I can't understand what the heck they are blathering about with the power law crap, though.

I generally find that Tim doesn't play very fair. He will obsess like a madman about the one (in some cases trivial) flaw that an oppenent has made and not adress whether it affects the overall larger argument. (And run around cackling at what idiots these guys are because they missed a comma or something.) That said, if EM or JohnA or anyone made a mistake, they should admit it. Even if Tim cackles and overblows it. (And Mann should also admit errors that come to mind as well...rather than dodging and saying "it doesn't matter". the impoact of an error is a different issue than that one has occurred. A real man will admit the error and treat the impact of it as a seperate issue.)

JohnA is still overdue to take his thermo whipping...

Yes, the distribution of the changes matters for impacts. But the scientists have nice maps showing those, so E&M don't have a leg to stand on.

TCO, I think your obsessing about trivial errors thing applies more to McIntyre than to me. Care to give an example, and explain why you think it is trivial?

Hi, Surface temperature measurements are not the temperature of the ground, but the temperatures taken in the air about 1 m from the ground, sea surface temperatures are measured in the sea, but water (as is the atmosphere) has a rather uniform heat capacity (there is some variation with temperature). The comment about heat capacity for measurements is another one of those no never mind things.

Tim, you waste your time on things like that curve or if someone got blocked from a blog by the moderator. Rather then digging into Steve's comments about MBH.

Eli: I'm just trying to think through this. Why doesn't it matter?

Hi TCO, because the surface temperature measurements do not measure the temperature of the physical surface, but of the air a short distance above the surface. Thus differences in heat capacity of the ground are irrelevant. http://tinyurl.com/nvjsf

Tim's simple poll at the start of here shows he does understand Essex and McKitrick's aqrguments.

Eli:

If I have two blocks, one with heat capacity of 1 and one with heat capcity of 1000 and the surfaces are equal, but the temps are either 50 or 100, a simple average will always give me 75. But the system has a different total energy with one situation (50,1;100,1000) or (50,1000;100,1). If I want to understand warming over a time period, and the two situations reversed, the simple explanation would tell me that no warming had occurred. And I would then miss AGW which had occurred.

the hockey stock is not robust for absence of bristlecones which aren't temperature proxies in the first place.

What more proof do you need?

indeed stock, as it has little to do with temperature ;-D

Please Hans. Where do you get this drivel?

With your insistence on rigorous science, shouldn't you wait until 2-3 other independent studies show the same thing, or are the marching orders explicit?

Best,

D

TCO you have a single atmosphere, with a heat capacity of pretty much exactly 5/2 RT per mole, and you have an ocean with a heat capacity of pretty much exactly 4.18 J/K-g. You measure the temperatures of each of these at the surface independently. Not two bricks.

Earlier, you said heat capacity was irrelevant as you measured a distance above the surface. Now, you are saying the heat capacity is invariant. Do you withdraw the earlier point then? And is the heat capacity really same of land, water, etc? I'm not even argumentative, just trying to hash it out.

Dano, M&M is replicated by Wahl and Ammann.
W&A also showed that the hockey stock is not robust for absence of bristlecones.

As for the other millennium reconstructions, that's playing hide and seek with data.

Pandora's box is open, the genie is out of the bottle.

Dano asks: "Please Hans. Where do you get this drivel?"

Just google Wahl and Ammann and you'll find out pretty quickly where most of this drivel comes from. Fortunately google also allows us to find out what Wahl and Ammann really said.

"M&M have thrown out essential data"

Which MEANS that bristlecones are essential to the hockeystick, which MEANS that the hockeystick is not robust, which was MBH's claim.

Graybill and Idso already proved way back when that bristlecones are not good as temperature proxies.

Hans:

which MEANS that the hockeystick is not robust, which was MBH's claim.

I don't believe that they ever claimed this. Could you please provide some details.

John

google "hockeystick robust"

"According to the Financial Times of April 1, 2006: "Goldman Sachs investors yesterday overwhelmingly voted down a unique shareholder proposal that claimed the Wall Street bank was misusing shareholder resources by pursuing an potentially expensive pro-environmental agenda. The proposal, submitted for consideration at Goldman's annual meeting by a small mutual fund firm called the Free Enterprise Action Fund, claimed that Hank Paulson had a conflict of interest in serving both as chief executive of Goldman and chairman of the Nature Conservancy, an environmental group". ... The Times reported that Steven Milloy, in representing the defeated FEAF proposal, criticised Goldman's donation of land to the Chilean wildlife conservation society (WCS) and also it's environmental policy which acknowledges the existence of global warming." http://www.treehugger.com/files/2006/04/goldman_sachs_i.php

Hans:

This is from MBH98 (appologies to others who sat this before)

But certain sub-components of the proxy dataset (for example, the
dendroclimatic indicators) appear to be especially important in
resolving the large-scale temperature patterns, with notable
decreases in the scores reported for the proxy data set if all
dendroclimatic indicators are withheld from the multiproxy network.
On the other hand, the long-term trend in NH is relatively
robust to the inclusion of dendroclimatic indicators in the network,
suggesting that potential tree growth trend biases are not influential
in the multiproxy climate reconstructions.

Could you please refer me to the place ... which MEANS that the hockeystick is not robust [to the presence of dendrochronologies], which was MBH's claim.

Oh, also while you are at it, could you please define what you mean by the bristlecone pines. Do you mean only the bristlecone pines or are there other species involved as well?

John

Dear TCO, I said that the heat capacity of the earth, as in the solid surface was immaterial because "surface temperatures" are measured in the atmosphere 1-2 meters from the solid surface. It is the atmosphere's heat capacity which is invariant for all practical purposes.

There is a thread somewhere in the Deltoid sarcophagus where Robert and I patiently explain to Mark Bahner how the heat capacity of the atmosphere is calculated and why, for all practical purposes it is independent of relative humidity.

The heat capacity of water, even in the oceans, is relatively constant also (it does vary some with temperature and salinity). OTOH, the heat capacity of the solid surface does vary strongly with composition, but so what. Except for boreholes, this is not relevant to any temperature measurement, and it is dealt with there explicitly.

MBH wrote:
On the other hand, the long-term trend in NH is relatively robust to the inclusion of dendroclimatic indicators in the network, suggesting that potential tree growth trend biases are not influential in the multiproxy climate reconstructions.

so:
the long-term trend in NH is also relatively robust to the exclusion of dendroclimatic indicators in the network.

If only 12 bristlecone proxies are excluded, the result is "without statistical merit" (W&A).

That aint robust.

MBH wrote:
On the other hand [etc]

I see there is a meeting on The Hill today where decision-makers are asking for input from the Murrican business community on how to adjust for climate impacts while keeping the economy robust.

I wonder why they aren't having meetings on an 8-year old first paper?

Or, alternatively, I wonder if there are any folk focusing on an 8-year old first paper in attendance at that meeting?

Or perhaps attending the increasing frequency of meetings like this or participating in actions like this.

Perhaps the time spent on atomistic quibbling loads up the inbox and prevents announcement delivery.

Best,

D

Hans, you seem to be confusing the terms "long term trend" with "reconstruction". Do you think they mean the same thing?

If so then why does Mann say But certain sub-components of the proxy dataset (for example, the
dendroclimatic indicators) appear to be especially important in
resolving the large-scale temperature patterns,

If not, then could you point to the statistics for the "long term trend" so that we could see the statistical merit.

John

Hans, if you need me to send you the 8-year old first paper, let me know.

BTW, I fergot to put this in the sentence such that it reads:

Or perhaps attending the increasing frequency of meetings like this or participating in actions like this or this.

HTH frame the extent for the quibblers-left-behind (QLB).

Best,

D

"If only 12 bristlecone proxies are excluded, the result is "without statistical merit" (W&A)."

Where in ROBUSTNESS OF THE MANN, BRADLEY, HUGHES RECONSTRUCTION OF NORTHERN HEMISPHERE SURFACE TEMPERATURES: EXAMINATION OF CRITICISMS BASED ON THE NATURE AND PROCESSING OF PROXY CLIMATE EVIDENCE (presumably their most recent paper) do W&A say this? Or is this yet another misquotation out of context? W&A actually say in their abstract:

"Also, recent "corrections" to the Mann et al. reconstruction that suggest 15th century temperatures could have been as high as those of the late-20th century are shown to be without statistical and climatological merit."

http://www.climateaudit.org/?p=607

Once again, in MM05b[EE], we presented an MBH98-type reconstruction without bristlecones or with reduced bristlecone weight, which yielded high 15th century values. In MM05b {E&E], we interpreted this result as only demonstrating the falseness of MBH claims of robustness to presence/absence of all dendroclimatic indicators, not as an alternative reconstruction. W&A stated that an MBH98-type reconstruction with reduced bristlecone weights (which they called an "MM" reconstruction) was without "statistical or climatological merit". We agree that an MBH98-type reconstruction with reduced bristlecone weights is without "statistical merit", but this does not mean that an MBH98 reconstruction with high bristlecone weights has "statistical merit".

The salient question arising from this is:

if an MBH98-type reconstruction with reduced bristlecone weights lacks statistical merit, then either all the other proxies are no good or the MBH98 method is no good or both.

We have never argued that an MBH98-type reconstruction with reduced bristlecone weights has "statistical merit". We have vigorously argued that an MBH98-type reconstruction with high bristlecone weights lacks "statistical merit."

Hans, you said:

the long-term trend in NH is also relatively robust to the exclusion of dendroclimatic indicators in the network.

If only 12 bristlecone proxies are excluded, the result is "without statistical merit" (W&A).

could you please clarify what you mean by the result. Is it the "long term trend", is it the "reconstruction" or is it both?

John

What again is the title of the W&A paper? (Hint: look at the first word)

And now you are trying to prove that MBH wrote that their reconstruction was not robust?

come on.

Hans, you seem to be really confused. W&A say that the reconstruction is robust with respect to the method used to calculate the pricipal components. They didn't say, as far as I can tell, that the reconstruction was robust wrt exclusion of the bristlecone pine proxies. In any case, W&A are not the same people as MB&H. Perhaps you could point to some statement in MBH98 or MBH99?

The problem boils down to the question "Are bristlecones valid temperature proxies"

According to Graybill and Idso they are not, if you then remove the bristlecones from the MBH reconstruction then the reconstruction is without statistical merit.

According to Graybill and Idso the MBH reconstruction is without climatological merit when the bristlecones are included, you might as well have taken the amsterdam stock exchange index.

If you want to question robustness do so on climateaudit, instead of murmuring there about entropy.

No, Hans, that is not the problem. I fail to see why you are having such a hard time understanding this. You stated:

Which MEANS that bristlecones are essential to the hockeystick, which MEANS that the hockeystick is not robust, which was MBH's claim.

MBH never claimed that the reconstruction was robust to the absence of the BCPs. This is not a trivial points since it gets repeated so much.

In regards to dendrochronologies being valid temperature proxies, I am afraid that I am not an expert on such. I do wish we had access to some of the experts though.

John

"I see there is a meeting on The Hill today where decision-makers are asking for input from the Murrican business community on how to adjust for climate impacts while keeping the economy robust."

"The Kyoto Protocol isn't merely a political document -- it's the equivalent of market research. Viewing the protocol from this perspective, we see that most of the world's nations believe climate change is real and urgent and are attempting to do something about it. That allows the commercially inclined among us to move on to the wonderfully crass questions about what products we might sell them. We start to ask: Whose appliances will the world buy? Whose fuel cells and photovoltaic panels? Whose light bulbs? Whose cars?
"This basic market intelligence may be the single most important key to thriving in a new economy. There is money to be made here -- lots of it. There are jobs here -- lots of them. This is Silicon Valley 2.0. We thrived with the information revolution, developing computers and software to change how the world works and plays. We can thrive again with a clean energy revolution, changing the way the world finds power for electricity and transport. But we can only thrive if we lead, if we take action now."
http://www.salon.com/opinion/feature/2006/04/04/hope/index1.html

Eli, what about the difference in heat capacity of the sea and land measurements. If a set area of ocean goes up 1 degree does it mean the same thing from an energy balance standpoint as if an equivalent area of land (air one meter above land)?

Also, if your air (one meter above land measurements) is isotemperature with the land underneath it, then the heat capacity of that land surface is relevant.

then the heat capacity of that land surface is relevant.

The standards generally state the instrument shelter should be above vegetation, particularly grass, so the ET of the vegetation is relevant too. The temperature of the exhaust from the lawn mower is relevant as well.

Kidding aside, ages ago when I was a weatherman you could see, a few hours after sunset not in winter, that the ambient temperature would rise for a shortish period ( a few to tens of minutes ).

Why? Soil holds on to its heat for a time and then releases it, causing the temp to rise.

Best,

D

Mann accuses M&M that by taking out the brislecones they are removing essential data from the MBH reconstruction.

So bristlecones are essential for the MBH reconstruction.

However, bristlecones are not good as temperature proxy as Graybill and Idso already showed in 1993.

Graybill, D.A., and S.B. Idso. 1993. Detecting the aerial fertilization effect of atmospheric CO2 enrichment in tree-ring chronologies. Global Biogeochemical Cycles 7:81-95.

I fail to see why you are having such a hard time understanding this.

Hans:

What got us started in this discussion is your claim that ... which MEANS that the hockeystick is not robust, which was MBH's claim.

Is there anything in MBH that backs up this statement? I say there is not.

John

you say there isn't, I see Steve McIntyre reporting it and I see Wahl and Ammann writing a paper with Robustness in the title, so it must be an issue.

Anyway the MBH hockeystick is proven without climatological merit in the first place so why debate on as minor exegetical question?

I think Steve's crticism is more subtle than what you state, Hans. Steve is not getting behind the Ibso paper, has not reviewed it critically, etc. He puts the onus on Mann(ites) to deal with the proxy kvetches.

is he?

Stephen McIntyre writes:
http://www.climate2003.com/mann.responses.htm

This expedient also fails to deal with the defects of bristlecone pine growth as a so-called "proxy" for temperature, discussed in pages 81-86 of our E&E article. There is a definite 20th century pulse in bristlecone pine growth. However, there are explicit statements in specialist literature (surveyed there) that this pulse is not due to temperature and MBH co-author Hughes has stated that the pulse is a "mystery". Our E&E article discusses issues pertaining to bristlecone pine growth, showing that it is unacceptable that world climate history should be held to depend upon a PC4 made up of such controversial data.

Few people care about the value, scientifically, of what people write on websites. The sciency folks have had mechanisms/forums in place for many decades to hash these things out.

Plus, for centuries, people have hand-waved and finger-pointed about results. What has made a change? People going out and getting their own data to show their point. Until that's done here, the finger-pointing is a mere distraction. And the finger-pointing is about an 8 year old, first paper.

Let us not forget that society is moving forward and not debating an 8 year old first paper.

Best,

D

What then was debated at the NAS panel dano?
Cherrypicking and hiding data, the forward movement is not that rapid since MBH.

LOL

Hans, Yup. In that paragraph, Steve is saying that Mann is basing his rec onstruction on a proxy that some other person has called into question. Is saying that Mann should defend that or should make sure that this is valid or that he is using proxies that are "in question". I'll bet you dollars to donuts, Steve's not putting his own imprateur on the Ibso paper.

Hans: again, I am surprised that you are missing the point. You said:

you say there isn't, I see Steve McIntyre reporting it and I see Wahl and Ammann writing a paper with Robustness in the title, so it must be an issue.

So, if someone else reports it and then a paper is written that that has the word robust in the title (in another context mind you) then MBH said it? While I am intrigued by this strange take on science I still feel that we should consult what people have said instead of what others write about them. So can you find for me the passage in MBH where they claim that the reconstruction is robust to the exclusion of dendrochronologies?

Anyway the MBH hockeystick is proven without climatological merit in the first place so why debate on as minor exegetical question?

True, and I see I shouldn't have brought up the issue - oh, wait - I didn't, you did!!! If you don't wish to debate minor exegetical questions, maybe you shouldn't bring them up.

John

You can't win john,

Either MBH wrote that their reconstruction is robust for inclusion of proxies, W&A and M&M showed it isn't for bristlecones. So MBH has no climatological merit.

or MBH wrote that their reconstruction is not robust for inclusion of proxies, then their number of samples is not sufficient for a reliable reconstruction. So MBH has no statistical merit.

Hans, I sincerely hope you're not expecting a "skeptical" outcome to the NRC process. If so, you're in for a disappointment.

You'd all better start reading Wahl and Ammann's material and paper to find out what it actually says. Here are some important points:

The W&A emulation of MM05's E&E method using the MBH 1450 proxy network produces a reconstruction without the bristlecone proxies that passes validation and is robust to the absence of the bristlecone proxies. So there's no problem going back to 1450. That hockeystick is there from 1450 with or without bristlecone proxies.

Their emulation of MM05's E&E method using the MBH 1400 proxy network produces a reconstruction without the bristlecone proxies that fails validation while if the bristlecone proxies are included it passes validation. So I guess robustness in this case means the temperature reconstruction passes validation against the instrument record or more recent proxies in spite of part of the proxies having growth trends that are not related to the instrument temperature record or other proxies.

So this argument about bristlecone proxies only affects the 50 years before 1450 (only 47 years now being claimed for MBH98 because one of the other proxies only started in 1403). 47 years, hmm, this is starting to look rather academic. However..

Compare the 1450 proxy network result excluding bristlecones in W&A's figure 5(c) with the 1400 proxy nework result including bristlecones in W&A's figure 5(d). The two agree pretty well from when the 1450 network result begins (1450 of course). Somehow, M&M think that even though the bristlecones show no signs of biasing the reconstruction (using the 1400 proxy network) after 1450 that somehow they could suddenly start biasing it before 1450. Let's get this clear. The 1400 proxy network (that includes the bristlecones) produces a reconstruction from 1400 to 1980. This is tested independently of bristlecones all the way from 1450 to 1980 and passes. The only way it could produce an invalid result for 1400 to 1450 is for something to go wrong during 1400 to 1450. No-one is suggesting this. The only suggestion is that something goes wrong in the 20th century. How can something going wrong in the 20th century produce perfectly reasonable results from 1450 to 1980 but then suddenly go wrong between 1400 and 1450?

Hans Erren wrote "According to Graybill and Idso the MBH reconstruction is without climatological merit when the bristlecones are included".

I wonder where Graybill and Idso wrote this? Couldn't have been in "Graybill, D.A., and S.B. Idso. 1993: Detecting the aerial fertilization effect etc." 1993 occured before 1998 as far as I'm aware.

Hans: Its a good thing that I am not trying to win then. What I am trying to do (so far without success) is to get you to show me where in MBH they say that the reconstruction is robust to the exclusion of dendrochronologies.

John

Chris, that is a bunch of cherry-picking. It needs to be valid overall.

Making a highly detailed response, TCO says:

"that is a bunch of cherry-picking"

TCO says it so it's true.

That's my Ozymandious mode...and don't be fucking talking about cracks in my statue. :)

Well, here I am, Tim! I want to start with a little "toy" example. Imagine a tic-tac-toe board (a 3x3 matrix) with the following in the corners: 15, 21; 25, 31. The first two are two readings (at different times) from a thermometer 1 and the second two from thermometer 2 at times T1 and T2. I think everyone will agree that you can fill in the averages among these various readings to get: 15, 18, 21; 20, 23, 26; 25 28, 31. So 23 is the "global average" of this example.

Now one more piece of data. The first thermometer is on Weathertop, which in this toy world has a constant barametric pressure of 500 mB while the second thermometer is from the Down in the Valley station with a pressure of 1000 mB. Question to think about then (and hopefully post about) before I post again: Is there any problem averaging station temperatures from different pressure regimes such as this? If so why and what can we do about it? If not why not and are you willing to defend that position to the death (so to speak?)

Dave: weighted average, not just simple average. Do you concede that geometric, harmonic, quadratic means are not appropriate?

I'd be interested in seeing a GHCN station at 5640m (~500 mb). Fascinating. Who washes the windows up there, and with what liquid? How do you judge the mileage for the trip - with the two legs or the hypotenuse?

And which stations in, say, the Alps (~900-850 mb) are GHCN stations, and those, oh, two are what fraction of the network? The Andes? Oh, wait: that's Tim's weighted avg. Never mind. Nonetheless,

Fascinating.

Best,

D

Tim, your response isn't fully responsive. Why use a weighted average? What are you protecting against if temperature, an intensive variable, albeit one which is a ratio of extensive variables, is perfectly ok as something to be averaged? We're not worrying about a "correct" temperature, after all, but just a self consistant one; i.e. one we can track over time and calculate deviations in.

Dano, I used to argue with a Dano on the Compuserve SF forum 11+ years ago. You wouldn't happen to be the same guy, would you? And I assume you're just trying to be funny. You know from my description of my "toy world" that it's designed for computational simplicity, not real-world emulation. Just as I picked the temperatures to all come out with integer averages.

Not the same guy, Dave. I'm being funny to point out stuff that commonly gets overlooked in the temp thingy.

Best,

D

I'm still waiting for Tim to say why we should weigh the temperatures and how they are weighed. I.e. what is this global temperature to be? Just the temperature 2 meters above the earth's surface level? If so I suppose Dano's questions about where the high altitude GHCN stations are might be useful. But the real question is just what this value is, (once properly determined), from a physics POV? Is it just a statistic or is it otherwise meaningful?

But I'll go on a little and hope Tim catches up. Since he didn't say, I'll assume that Tim is thinking that we should weigh via atmosphere vs weighing via relative surface area.

So we'll give our high pressure station twice the weight of the low pressure station. Then the mass-average temperature is (15 + 21 + 2x25 + 2x31)/6 or 148/6 = 24.67 vs 23. You won't like that decision as to Tim's meaning, I suspect, but Hey!, I asked for more than one sentence. We're looking for purpose here. The purpose of a derived figure has to come before the proper method for deriving it comes. [Note, I'm not looking for deep thoughts here. Simply clarity.]

Yoo Hoo, Tim!

I thought you were interested in a discussion. Have you forgotten I'm down here?