Is the 'hockey stick' broken? 21 February 05

If you will take a critical look at the plot of temperatures that you linked, you will see the issue clearly. The Mann versions of the past 1,000 years of climate do not rise as high or plunge as low as the other versions.

The issue is not about the exact temperature as much as it is about the difference between the highs and the lows. Mann would have us believe that the Little Ice Age was about 0.3 Celsius degrees cooler than the Medieval Climate Optimum. There is too much literature in the technical journals, history texts, and contemporary literature to believe that to be possible. The actual differnce was more than a degree.

The temperature today is not significantly warmer than it has been in the past. The existing models appear to attribute most of the temperature rise during the past 150 years to the increased concentration of carbon dioxide. I believe that most of that temperature rise was natural and that it is wrong to attribute it to carbon dioxide and to extrapolate into the future based on predicted concentrations of carbon dioxide.

It may be that carbon dioxide caused some portion of the current warming. Even IPCC in the TAR acknowledged that no one knows how much. Most responsible scientists appear to believe that the carbon dioxide contribution is small. We cannot believe Mann just because he deigned to assert that it does not matter if he was wrong. How self-serving is that anyway? “Oops, I made a boo-boo. Oh well, I am still a wonderful scientist.” (Snort)

It appears that Mann and his cohorts established the Realclimate website solely for defending their version of temperature history outside of the technical literature.

The upcoming issue of the Journal of the Geophysical Union will contain an article by McIntyre and McKitrick that criticizes Mann’s technique. We should follow the events and see what happens.

Disclaimer. No one paid me anything to write this. (Anyone who is willing to pay me is welcome to do so.)

The hockey stick is probably right (I’m no climate scientist), but if it is wrong, and there is more climate variability, then we might be in for a lot more trouble. If human emitted GHGs do contribute to GW, even in a very tiny way, then this could trigger a much larger climate response (since the climate varies so wildly from natural causes). We should redouble our efforts and do all we can to reduce our part of the contribution, because we wouldn’t want to trigger wildly fluctuating nature into a runaway global warming scenario. And I do think it is well established for Earth, Venus, and Mars that GHGs have an impact on climate, and increasing these through human activities would very likely also have an impact, even in the “small amounts” (as skeptics see them), especially since climate is so very sensitive to natural forcings or inputs. Why poke a hockey stick at a hornets nest, when reducing our GHGs can be done in a way that is a great boon to our pocket book & the larger economy?

N,

You may not have easy access to Nature and Science – that’s one of the benefits of having Oxford University on my doorstep. I’ll quickly quote from Science on 11 Feb (I’d post the whole thing but for copyright restrictions).

The article begins by discussing the latest ‘hockey stick’ controversy with regard to the McIntyre and McKitrick study – something which is extremely difficult to understand unless one has many days to spare and advanced academic training in statistics (which I don’t – even the editor of Geophysical Research Letters apparently admits to not understanding the paper!). The article then goes on to discuss the Nature paper by Anders Moberg (Stockholm Uni) et al, who added 11 proxy records ranging from cave stalagmites in China to an ice core in northern Canada.

Says Science: “They also used a wavelet transform technique for processing the data, a new approach in millennial studies. Moberg and his colleagues found that temperatures around the hemisphere fell farther during the Little Ice Age of the 17th century than in Mann’s reconstruction and rose higher in medieval times. The medieval warmth equaled that of most of the 20th century, but it still did not equal the warmth of 1990 and later.”

In other words, the warmth of the last decade and a half appears to be unprecedented in the last thousand years, giving support to the original IPCC statement. And as Lynn suggests here also, greater natural variability is not necessarily a good thing, nor does it discount anthropogenic interference with increased CO2 concentrations, as Moberg et al state in their conclusion.

To quote: “The main implication of our study, however, is that natural multicentennial climate variability may be larger than commonly thought, and that much of this variability could result from a response to natural changes in radiative forcings. This does not imply that the global warming in the last few decades has been caused by natural forcing factors alone, as model experiments that use natural-only forcings fail to reproduce this warming. Nevertheless, our findings underscore a need to improve scenarios for future climate change by also including forced natural variability—which could either amplify or attenuate anthropogenic climate change significantly.”

Well, firstly I am sorry for my terrible english.

From my point of view the matter is not too complex or hard to understand. Let’s study it:

There are a decreasing community of scientists that believe the current global temperature increase is not “special” at all.

Well, please Mark: help us. Can you inform of any other simillar events in our old planet history? I mean, as soon as somebody presents a so violent change in temperatures and gives a piece of proof of nothing special changed or happened (massive extinctions, suddenly frozen mamouths , etc.) I will move from my environmental position to defend Exxon and Shell from now on and forever and ever. Otherwise, maybe they will have to admit that something is really happening.

I don't want to discuss here wether greenhouse effect gases are or not the guilties, but I think to admit a problem is the first step to solve it...

... in case there is still a solution for the human race.

but not to either Nature or Geophysical Letters. I do not live near Oxford. I saw the article that you quoted. I agree that the temperature post-1990 is higher than any of the reconstructions shows for the Medieval Climate Optimum.

I too, admit to having a limited understanding of the mathematics of the McIntyre and McKitrick criticism. However, their ability to use Mann’s algorithms to generate hockey stick lines from random noise persuades me that the Mann reconstruction is faulty.

The real question is, “By how much is the temperature of the 1990s higher than what we think it was in 1100? The difference between the Moberg estimate for 1100 and 1990 is essentially zero. The part of the temperature curve that may be abnormal is the part above the zero line in the chart. The Moberg data indicate that the temperature rose about 0.4 C degrees between 1850 and 1990, and that it rose approximately 0.08 C degrees post-1990. The way that I see it, about 83% of the temperature rise since 1800 is probably natural and about 17% may be the result of the increased carbon dioxide concentration.

That would mean that the increase of 100 ppm (275 ppm in 1800, 375 ppm in 1990) caused a temperature increase of 0.08 degrees. If the concentration of carbon dioxide increases by 375 ppm i.e. doubles (BTW, I do not think that there is no real reason to believe that it will.) the increase in the temperature would be about 0.3 C degrees (375*0.08/100 = 0.3). I see little to fear from such a change.

I note that the Science article and Moberg plotted data only through the year 1998, the year of the last big El Nino and the year of record high sunspot activity. They and you have failed to mention that the temperature has cooled from that high point and that for the last two years the temperature has been decreasing. You can look at the GISS data at http://www.giss.nasa.gov/data/update/gistemp/ZonAnn.Ts.txt. Will the temperature continue its downward trend? No one knows for sure, but we should be entering a period of relatively low sunspot activity, so we shall see if solar activity is more important than IPCC is willing to acknowledge.

“It may be that carbon dioxide caused some portion of the current warming”, this suggests some acceptance of the warming theory. By logical extention, a look at rising GHG concentrations should guide you to see the possibility of further warming accompanying further GHG rises.

Anyway, I do agree on the point of understated temperature variations, a look at the documentary record alone (usually more reliable then other evidence, as was witnessed) shows a more dramatic swing. Barriendos et al/ Rodrigo et al, both highlight this with respect to the Iberian peninsula and are worth a look at.

The point does not change: climatic variability is really only affected by a few forcings;

volcanoes (a sporadic signal, not relevant to Climate Change, though lack of vol`s may account for small temp` rises).

The sun, very important, but sunspot activity timescales are predicted-only the amplitude of solar irradiance can vary (Reichel et al 2001 talks of “the existance of a physical mechanism linking solar activity to climate variations”) which works on near decadal scales. But, crucially, increases in solar irradiance, which accompanied the warming of the 30s/40s, would be expected to have occured post 1980, to explain recent temperature rises. Increased solar irradiance did not occur post 1980, but is anticipated to start rising soon. this discounts the sun as the cause of recent warming.

Hansen et al 1990 found a “chaotic behaviour” signal with a temperature impact of up to 0.4C, “due to no forcing at all”. This can already be discounted as the only forcing, as is too small a rise to explain recent rises, which have occured over and above generally low solar imputs, ( and if you’re a fan of the “dimming” theory) increased “dimming”.

So finally there is the impact of varying atmospheric composition in the stratosphere…....I think I`ll leave it there!!!!

What do you beleive it is that is “natural” and is forcing global temperatures at the moment?

I’m a bit perplexed about where you get your figures from, N. “The Moberg data indicate that the temperature rose about 0.4 C degrees between 1850 and 1990, and that it rose approximately 0.08 C degrees post-1990.” That’s strange – Moberg et al use the same instrumental data as everyone else, which shows temperatures rising 0.6C between 1850 and 1990, and much more rapidly thereafter. So your charming back-of-the-envelope maths on the imputed forcing of this will also be way off, I’m afraid. The top graph of the original blog is the instrumental temperature record, which is undisputed. Jim Hansen from NASA, by the way, estimates that 2005 will tie with 1998 as the warmest ever year. See http://www.livescience.com/environment/050210_2005_temp.html Cold comfort for your cause, I’m afraid.

The instrumental record only goes back to 1880; the GISS folks recently dropped the data before 1880 because they decided that they were not reliable. So, we will have a look at the graphic that you linked. You will see that the Moberg trace (heavy blue line) shows a nearly horizontal line at -0.48 degrees between 1750 and 1850. The temperature difference between that line and the 1938 peak is about 0.44 degrees. So, my estimate of the temperature change, according to Moberg, was reasonably accurate.

If we look at the temperature change between the depths of the Little Ice Age, we see that it was just over 0.7 degrees lower than the 1961-1990 average.

But, OK I will accept your estimate of 0.6 degrees between 1850 and the early 1990s. That makes the denominator in my fraction larger and reduces the percentage of the total temperature change that is possibly abnormal.

Have it your way.

The instrumental record is not as undisputed as you believe. Two things compromise its accuracy. First, many (approximately a third) of the original stations have been shut down. Those shut down were predominantly rural (cooler) stations. The average temperature will rise every time you eliminate a cooler station. For example, the average of 2, 4 and 6 is less than the average of 4 and 6.

The second thing that compromises the accuracy of the surface record is the inadequate correction that IPCC makes for the urban heat island effect (UHIE). We saw in a paper cited by Dan just a couple of weeks ago that the UHIE can be as high as 15 F degrees in colder areas, even in relatively small urban areas. The city studied was Fairbanks, Alaska, pop about 30,000.

It is just half past February. It probably is too soon for even one as smart as Jim Hansen to be making accurate predictions. We shall see.

Mark, your quote her: “Estimates that 2005 will tie with 1998 as the warmest ever year”.

Based on a previous graph you posted on that, I looked at the pattern and since I actually KNOW how to read a graph, I thought that 2005 will become a hot year. In fact, it may even top 1998 based on my educated guess looking at the climate pattern from that graph you posted earlier.

With regards to Norbert’s simple analysis based on a percentage calculation and a linear response to CO2, I just have to let it go with him.

How he can criticize other scientists when his ability is at the grade-school level is beyond all hope here. No wonder he has such a difficult time understanding things objectively.

When I read that, I thought, Great God Norbert, is that the best you can do?

And to have others here reject everything ever done in climate science over the last hundred years based on that bit of arithmetic which is simplistic at best to describe our climate system is beyond my ability to believe anyone could be so presumptuous and arrogant let alone believe that anyone would take that seriously.

Anyone who would bet our future at doubling CO2 based on that bit of simple math with all the complex climate feedback loops and suggesting linearity!!!!! (if Norbert understands the concept) and yet be critical of computer models as being wrong! And you suggest that he uses the wrong data to boot!

I am still in shock as to how Norbert keeps getting worse rather than better. I conclude there is absolutely no hope for him.

He needs medical help fast since it is now becoming a state of emergency. He desperately needs to get a brain transplant since the one he owns is permanently flawed!

Anyhow, based on your post and description, if the temperature went up by 0.4 in 140 years and went up by 0.08 since 1990, then using Norbert’s linear approach, we have (0.08/15) / (0.4/140) which equates to a warming rate in the last 15 years to 1.9 times the rate of the period between 1850 and 1990.

Therefore, maybe even Norbert does not know how to even use his bogus linear approach since the conclusion here based on your post is that we are warming at a faster rate even when we use a simple linear calculation.

Later, Dan

Norb, you need to read empirical evidence at the library.

1. Karl, in 1988, addressed the station closure issue. You can be forgiven if you missed it. But you can’t be forgiven if you haven’t read the two-dozen or so other papers since then on the topic.

2. The UHI is spatially limited. If you wish your argument to be valid, you’ll want to show the extent of the UHI and whether it extends to the ICAO station recording the temp. Do Fairbanks, that’s a good one.

As I have done transect work quantifying the UHI of a Northern CA city, I am uniquely qualified on this blog to say that you don’t understand the IndyFunded cr*p you are parrotting.

Once you get off concrete, the temp drops off rapidly. Especially in irrigated farm fields.

And where are the majority of thermometers in the US? At airports. In the middle of fields.

Now. Go out and get the spatial extent of, say, 10 UHIs. Then tell us where the thermometers are for those UHIs, and whether they are located within the UHI dome.

Good luck in your quest.

D

effects do not extend outward from urban centers.

S.A. Bowling appears to believe otherwise. She says,

“The Fairbanks area is subject to strong urban heat island effects (measured to be as much as 13 °C) when skies are clear in winter (Bowling and Benson, 1978). Summer heat islands have hardly been looked at, but they now appear likely to have more effect on recorded climate than do the large winter ones, which are masked by large year-to-year variability in winter and seem to be more confined to the city core.”

She goes on to say,

“January of 1989 was a record setter in much of Alaska. Not, however, officially in Fairbanks, where the official temperatures are recorded downwind of the city. Unofficial temperatures on the upwind side of Fairbanks were much lower, as were many at surrounding climatological stations.”

http://climate.gi.alaska.edu/Bowling/AKchange.html

The official temperature station is downwind of the city by 4 to 6 miles.

Let’s see. Whom shall I believe? Shall I believe Dano or shall I believe Ms Bowling, a professor of physics at the University of Alaska (retired) who has studied the issue?

I don’t seem to believe anything, norb, except when you attempt to obfuscate and rephrase incorrectly to maintain your uninformed position.

You’ll note, of course, that I said:

The UHI is spatially limited.

This is true. This is also borne out in the paper from 1990 you refer to.

I note that you haven’t done this for any other stations, but choose to use this one to make your point for the entire planetary surface.

The UHI has had little effect on global temps overall, as urban areas comprise ~ 4-5% of the total surface area of the planet. Methods have been developed to address this issue.

You have no idea whether or not other temp stations are within UHIs. Or how many. Or how this is addressed.

BTW, if you read enough papers on UHIs, you’ll likely figger out who I am, as I am acknowledged in a couple.

Now, to address your slavish reliance on predigested information from IndyFunded sites, we should take, fer instance:

Epperson DL, Davis JM, Bloomfield P, Karl TR, McNab Ll, Gallo KP 1995. Estimating the Urban Bias of Surface Shelter Temperatures Using Upper-Air and Satellite Data .2. Estimation of the Urban Bias. Journal of Applied Meteorology 34:2 pp. 358-370.

Lays groundwork for quantifying effects across planetary scales.

Unger J, Sumeghy Z, Gulyas A, Bottyan Z, Mucsi L 2001. Land-use and meteorological aspects of the urban heat island. Meteorological Applications 8:2 pp.189-194.

Finds a medium-sized city has a strong relationship between UHI and distance.

Li Q, Zhang H, Liu X, Huang J 2004. Urban heat island effect on annual mean temperature during the last 50 years in China. Theoretical and Applied Climatology 79:3-4 pp. 165-174.

Finds 50 years of urbanization in China has had little overall effect on the observed warming in China.

and consider them. There are numerous other papers that have found the same thing, and I can supply them.

We wish the non-rubes well in their reading.

Best,

D

You have said that airport runways do not affect thermometers a couple of hundred meters away in the infield. We find that the UHIE of a relatively small city, Fairbanks, affects a thermometer that is approximately 8 kilometers distant.

The situation is that a city of 30,000 affects a thermometer that is 8 km away. Yet you claim that airports imbedded in metropolitan areas of millions, e.g. Kennedy, Newark, LAX, La Guardia, Washington National, and O’Hare are unaffected by UHIE.

The magnitude of the UHIE from this city is as much as 13 degrees C. I do not believe that your adjustment regimen includes UHIE of that magnitude.

I do not need to find and study other cities, it is not my hypothesis or theory; it is yours. You need to modify it to be all-inclusive, so that it will explain all of the observations. A single exception, Fairbanks, is sufficient to cast doubt on the entire process. I am sure that you know that is how science works.

Your theory did not identify Fairbanks as an area needing extra care. You cannot know how many other such cities exist; there could be hundreds of them for all you know. Fairbanks is a small city in a river valley in a cold clime. How many such cities are there?

The fraction of urban area in the world is not the issue. The issue is the fraction of climate monitoring stations in urban areas.

Well, the unplumbed depths of your underinformedness should fuel the dreams of many an adventurer, were it not for the blatant mischaracterizations that inform your arguments.

You have said that airport runways do not affect thermometers a couple of hundred meters away in the infield.

I did not.

I said no such thing.

Most people would call you a lying POS after that, but I find your mischaracterizations pathetic rather than a lie.

I said the majority of thermometers (measuring stations) are at airports where its cooler.

I also said you shouldn’t extend Fairbanks to the entire surface of the planet.

I do not need to find and study other cities, it is not my hypothesis or theory; it is yours. You need to modify it to be all-inclusive, so that it will explain all of the observations.

It has. I told you about it already.

As I said, you don’t know sh*t (actually I said You have no idea whether or not other temp stations are within UHIs. Or how many. Or how this is addressed.) but it’s the same thing.

The theory is well-grounded in the literature, which you don’t know.

Due to the large number of stations in sparsely populated areas (over 85% – 70%SE) the impact of UHI is not large in the US. (Karl, Diaz and Kukla 1988 Journ Clim 1099-1124 that I referred to before that you don’t know).

And if you had access to the journals, the refs and statement I made previously would make sense to you.

You can’t hand-wave with me, boy. Especially not on this subject.

D

LOL Thanks!

“Once you get off concrete, the temp drops off rapidly. Especially in irrigated farm fields.

And, where are the majority of thermometers in the US? At airports. In the middle of fields.

Now. Go out and get the spatial extent of, say, 10 UHIs. Then tell us where the thermometers are for those UHIs, and whether they are located within the UHI dome.”

I found one thermometer that is within the UHI of a small city, 8 kilometers from the city center.

Perhaps, you should cease with the profane invective and the supercilious and condescending style, review your own posts (which you cannot seem to remember) and respond to the legitimate question – to wit – “Does your theory explain the Fairbanks experience and if not what do you plan to do about it?”

Your inability to remember what you wrote makes me wonder how well you remember what the articles that you cite say.

Stop dissembling and distracting away from the fact you don’t know what you’re talking about.

You have failed to show whether Fairbanks is typical or an outlier.

You have not shown any familiarity with the literature.

You have repeatedly mischaracterized my statements to cover up your being uninformed.

Now:

Does your theory explain the Fairbanks experience and if not what do you plan to do about it?

Yes it does.

Sadly, you don’t understand the issue so you thrash about here, exaggerating, mischaracterizing, dissembling away.

Your reliance on predigested info is making you look silly, in addition to uninformed.

Nor have you gone beyond Fairbanks to quantify spatial extent and intensity of UHIs. That is likely because you don’t know what you are talking about.

So:

- It is not my theory.

- The theory is well-grounded in the literature. There are literally dozens of papers that you haven’t read.

- The amount of UHI bias has been quantified, more than once [e.g. Karl, Diaz and Kukla 1988 Journ Clim 1: pp. 1099-1124, Jones, Kelly, Gooddess, Karl 1989 Journ Clim 2: pp. 285-290 ] . There is one well-known outlier paper.

Note how long this has been known and quantified.

- The sampling issue has been quantified, a number of times. [e.g. Karl, Knight and Christy (yes, THAT Christy) 1994 Journ Clim 7: pp 1144-1164, and others above].

- The extent of the UHI drops off rapidly once you take away concrete [e.g. refs above, and what the heck one more: Mihalakakou, Santamouris (the Med. person), Papanikolaou, Cartalis and Tsangrassoulis 2004. Pure Appl Geophys 161: pp. 429-451].

- I already gave you places in the literature where you can start.

- I already excerpted something from the literature that explains.

- Here is more:

The Northern Hemisphere landmass may contain a spurious warming trend which is, at the maximum, [.1C] over the first 8 decades of the [20th C]...+-[.05C]...this bias is an order of magnitude less than the total trend… (pp. 285 and 289) Jones, Kelly, Gooddess, Karl 1989 Journ Clim 2: pp. 285-290.

So, your job if you were any good at argumentation would be to take something concrete, such as what I have already given you over a series of posts (as opposed to making sh*t up) and try to either state that the papers are incorrect (do give specifics as to why, with backup and attribution) or trot out your own examples of empirical evidence that state something to the contrary.

That’s how it’s done.

Hope this helps your argumentation in the future,

D

Ok, it is my turn Dano. You had enough fun.

I posted before that Norbert needs a brain transplant and I guess that is more a fair statement than ridicule since he is consistently proving himself to be rather incompetent.

Norbert cannot read a graph on Alaska correctly without misleading people as to what the graph actually shows.

He posts tabular NASA data with no explanation of that table or units in that Table explaining precisely what those numbers actually mean.

He does not even know how to communicate his own case for greater clarity. Maybe he likes to confuse people into believing him by posting NASA tabular data without adequate commentary. Tables are difficult for people to understand. Graphs are easier yet even he cannot read a graph correctly himself.

Norbert does calculations using bogus ratios and linear assumptions to calculate the temperature rise from doubling CO2. He does this and yet criticizes computer models for being wrong.

He also bases his bogus calculations on temperatures he often deems as unreliable. Maybe the temperature data is reliable enough for him to perform bogus calculations but never reliable enough for computer models run by experts in the field to predict accurate results.

How more biased can that possibly be?

Since I already posted on many these aspects before, I need not do it again unless Norbert wants me to go there AGAIN!

Dan