GLOBAL WARMING BOMBSHELL: Hockeystick Broken

MIT Technology Review ^ | 15 October 2004 | Richard Muller

[palmer]

For example they use Keigwin to show that the Sargasso had cooler temperatures during the LIA without mentioning that Keigwin thinks this is due to a shift of currents.

I downloaded the Keigwin-1996 data. It shows SST estimates on 50 year intervals with warmth estimated at 1.5C warmer 25 years ago than 925 years ago. Admittedly a crude measurement subject to ocean currents, but nonetheless matches the MWP and LIA eras.

[palmer]

Sorry, make that 1.5C warmer 925 years ago than 25 years ago.

[palmer]

Downloaded demenocal-2000 (mentioned by Soon as being "marginally warmer that at present"). The data shows the MWP being from 0.1 to 0.5 C warmer than 88 years ago (not the present). That counters the Keigwin data somewhat and doesn't allow comparison to the 20th century.

[palmer]

You then said "Apparently Mann used just nine locations out of all the available data, just 5 for North America." No, that is not correct. First, it depends on which paper you are talking about. In his 98 paper that looked at the global temperature he used over 100

Downloaded the Mann-1998 data. The record is as he stated: a large warmup from the LIA. Unfortunately this record starts with the LIA. The other problem is appending measurements from 1981 through 1998 onto the end of the graph containing proxy measurements. Surface temperature measurements (with a documented 0.1 to 0.15 warm bias) are not the same as proxy measurements! The reason is the proxy temperatures measurements are a different kind of measurement which will reflect cold and warm extremes differently. That makes it impossible to say how much warmer the 80's and 90's were to other decades measured by proxies. The evidence is obvious in the data: where they overlap, the proxy and measured temperatures do not match up very well.

[Yelling]

We seem to be going in circles. No one argues that the SST of in the Sargasso was warmer than than it is now. What Keigwin put it down to is a shift in the currents. Different currents - different temperatures. I did go through this before with WOSG.

If you want to argue that a warming in the world caused a change in the NAO which caused a warmer current to move then fine. But that is not what Soon says or that you have argued.

Wake me if you find something good.

[palmer]

We seem to be going in circles.

I am making steady progress. You are the one repeating yourself. There wasn't a 0.4 C warming since 1980, there is a 0.1 to 0.15 degree bias in that estimate. The increase since 1980 is a deviation comparable to many other decades in the past and doesn't show up in some of the proxy measurements (e.g. briffa-1998).

The answers I have gotten so far are:

* there were decades in the MWP (and even in the LIA) warmer than the 80's and 90's.
* There was an increase in temperature during the 1900's as a whole, but mostly concentrated before 1950.
* There was variability between periods throughout history that match the variability in this century.
* The Mann 98 deliberately smoothed out historical data to hide that variability.
* That paper did not smooth the 1980's and 1990's and used surface measurements with bias in place of proxies.
* I can conclude, so far, that hockey stick is an artifact.
* But I can't make the MWP warmth conclusion yet globally, I need to look at more data.

[Yelling]

You are correct I am repeating myself because I had this same argument with WOSG, We first covered Keigwin and I showed that he thinks that the change was caused by a shift in currents. Then you bring him up!

Same with deMenocal. I already posted about him above yet you bring him up again. I even quoted him. Someone asked him about the use of his data to show a MWP and he said "Peter deMenocal, an associate professor at Columbia University's Lamont-Doherty Earth Observatory, used sediment records off the coast of Africa as a proxy for ocean-surface temperatures. He says Mr. Soon and his colleagues could not justify their conclusions that the African record showed the 20th century as being unexceptional. "My record has no business being used to address that question," the Columbia scientist says. "It displays some ignorance putting it in there to address that question."

This is what I mean by going around in circles. When you bring up something new I will consider it.

In regards to your answers, I wish you well and an looking forward to seeing you post something about them. However as you work through the data, please ask yourself if you have corrected for all the things that you accused Mann of not correcting for.

In regards to Mann, if you are convinced then you should publish your results. However nothing you have yet posted backs up one of your assertions.

Now, I am engaged in another good discussion (this one on radiative forcing functions) so good night.

Y.

[palmer]

Peter deMenocal, an associate professor at Columbia University's Lamont-Doherty Earth Observatory, used sediment records off the coast of Africa as a proxy for ocean-surface temperatures. He says Mr. Soon and his colleagues could not justify their conclusions that the African record showed the 20th century as being unexceptional.

That's essentially what I said as well. Maybe it wasn't clear or maybe you just skimmed it and thought I used it to justify the conclusion that 20th century was unexceptional. No, I did not. Since his data is very coarse and at least 88 years old, it says nothing about the 20th century, exceptional or otherwise.

Well you are welcome to end this discussion without addressing my concerns about Mann. As for your suggestion for me to write a paper, I would accept Soon's with all its errors as far superior to anything I could put together. However since I have not made up my mind like you have, I am willing to keep researching the raw data and commenting on all of it whether it supports my view or not. The example above is just one case, Jones98 was another that could support the hockey stick provided I can figure out his normalization technique for 1960 onwards. Otherwise I must judge it to be inconclusive (or tweaked and therefore useless like the Crowley-Lowery dataset).

But you are also welcome to provide your own analyses of the data. I think it would serve your case better than simply pretending to scientifically review the Soon paper.

[Yelling]

That's essentially what I said as well.

Sigh, no, you did not. What you said is that the paper shows temperatures that do not support some aspect of warming during the MWP. What I am saying is that the paper can't be used for that since it doesn't measure that. What the author says is that the wind and current pattern shifted to cause cooler currents with more upwelling. This caused sea surface temperatures to drop. It is not a reflection of any surface temperature. You go to a beach on a very warm day with an offshore wind and the water is cooler than you expect. That is upwelling. nothing to do with temperature.

However, I do find it somewhat amusing that you are prepared to accept any aspect of what a paper says to support your ideas and yet you accuse me of being biased. Read what the paper says and then you will be in a much better position to comment on it.

Regarding CL, could you comment on how it was "tweaked" and therefore useless?

Finally, regarding Soon! Lets see. It was presented by WOSG and I showed how it is a very poor attempt. You then read it and seemed to feel that it was sound. So when I do a critical analysis of it you say that I am "simply pretending to scientifically review the Soon paper." So I would guess that you are simply pretending to admit that there are errors in it?

I am not leaving the debate, but I do feel that I have done more than my share of the research. I have had to dig out several papers, read them and try to understand what they show and then present and defend my point of view against people who don't wish to read the papers. While I find reading technical papers somewhat enjoyable it is time consuming. If you wish a real debate about this then post some real comments that I can look at and review.

One final comment - I think you sell yourself short. I feel that you could actually do better than Soon did on that paper. I am pretty sure I could even though I am an engineer, not a climatologist - but then again Soon isn't a climatologist either. That may explain something.

Regards,

Y.

[palmer]

upwelling

Took another look at the demenocal-2000 data and he mentions strong seasonal upwelling. If this data is only measuring strength of that, then I'll ignore it and move on to the next data set.

You then read it and seemed to feel that it was sound. So when I do a critical analysis of it you say that I am "simply pretending to scientifically review the Soon paper." So I would guess that you are simply pretending to admit that there are errors in it?

You have provided no scientific review of the Soon hypothesis and conclusions as I did in post 131. You merely presented a bunch of nitpicks that you found in various GW sites about the errors he made. You claimed a "devastating" attack, but provided no systematic review of the paper. I on the other hand have looked and continue to look at the actual data to see if it supports Soon's hypothesis. Because the bottom line is that irregardless of what Soon said and how he said it, I (and most other people on this forum) want to know whether or not his hypothesis it true.

As for CL, the notes from his readme are as follows:

Removal of all forcing except greenhouse gases from the ~1000 year time series results in a residual with a very large late 20th century warming that closely agrees with the response predicted from greenhouse gas forcing.

His assumption of CO2 forcing is not supported by any raw data in his possession, it is a hypothesis only supported by simulations. He then smoothed his historical data based on assumed statistics about natural mechanisms that also labels "forcing" although they are not the same thing (i.e. particulate cooling is not forcing). So his historical data was smoothed to (conveniently) eliminate any MWP or LIA warming. He did not choose to release his raw data.

[Yelling]

Humm, I did provide several "nit-picks" that showed that Soon was not interpreting the data correctly. And the "nit-picks" that I found were based on papers that were presented to me by you and WSOG. So in fact statistically things aren't looking too good for Soon (and no, you can't accuser me of bias since I had no hand in selecting the papers). Since he has not understood these, how many others has he got wrong? I don't intend to spend my time going through all his references, however I am interested in the ones where he seems to have his facts straight and if you can recommend any (after you have reviewed his paper to ensure that he has his facts right) I would appreciate knowing about them.

I on the other hand have looked and continue to look at the actual data to see if it supports Soon's hypothesis. Because the bottom line is that irregardless of what Soon said and how he said it, I (and most other people on this forum) want to know whether or not his hypothesis it true.

Err, I hate to pop your bubble, but it was you who wanted to accept Soon as given. I, on the other hand, did look at the data and the papers and presented the information. I do find your comments about me posting from a GW site ironic. If I post from somewhere else I generally reference or at least say "from a site" and anyone can ask me if they wish. If you can find any evidence of me posting from a "GW site", please post it. Right or wrong, my comments are my own.

On the otherhand earlier on this thread I came across a post, cut and pasted with out reference from the CO2 Science site. Your comments on that please?

However in regards to the truth. As you are, I am also merely a lone individual in search of scientific truth. Although you seem to have a strong interest in rhetoric as well.

His assumption of CO2 forcing is not supported by any raw data in his possession, it is a hypothesis only supported by simulations. He then smoothed his historical data based on assumed statistics about natural mechanisms that also labels "forcing" although they are not the same thing (i.e. particulate cooling is not forcing). So his historical data was smoothed to (conveniently) eliminate any MWP or LIA warming. He did not choose to release his raw data.

Like a spiral in a spiral and a wheel within a wheel ... and around we go in circles. You are not looking at the dataset or methodology that was given in the paper that I referenced because you are not looking at the relevant paper. There was nothing in that paper talking about CO2 forcings! You came up with that by looking at the data for another paper of his. There is a reference to the data that he used but nothing about the methodology. So without knowing anything about it you say that the data is smoothed, etc. Your comments may be valid as applied to Crowley 2000, but mean nothing as applied to Crowley and Lowery 2000. Your appeal to probability is looking like a long-shot.

Oh, and a small point but in climatology particulate cooling is considered a forcing.

Again, please wake me if you find anything of interest.

[King Prout]

he'll find some way to brand it heresy.
the sheeple will baaa right on along.
mark me - you'll see.

[palmer]

Critique of the Mann et al Northern Hemisphere Average Temperature Reconstruction
BY
* Steven McIntyre Toronto, Ontario
* Ross McKitrick Department of Economics, University of Guelph.
http://www.uoguelph.ca/~rmckitri/research/trc.html

I looked at the their link climate2003.com where they talk some more about a growth pulse for bristlecone pines which skewed Mann's 1998 results. I also read the rebuttal at realclimate.org/index.php?p=111 which basically dismisses the critics because they use a linear correlation coefficient. Also says "we've moved on" and they are investigating the forcing that causes global warming.

I have to read more of their arguments, but they sound a lot like yours. Attack the scientific credibility of the critics, point out various errors the most basic of which is that the critics used only 10 chronologies instead of 50 to cover the whole time period (1400 to 1980) instead of step-wise reconstruction using all 50 chronologies. This is in their words "sharply at odds with virtually all other empirical and model-based estimates of hemispheric temperature trends in past centuries". That sounds more like choir practice than science, but I'll have to study this further.