Guest Post by Willis Eschenbach
There’s a new study entitled “Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation”, Shakun et al. (paywalled, hereinafter Shakun2012). The paper claims to show that in the warming since the last ice age, CO2 leads temperature. Anthony wrote about it in his post “A new paper in Nature suggests CO2 leads temperature, but has some serious problems“. The press release says (emphasis mine):
A new study, funded by the National Science Foundation and published in the journal Nature, identifies this relationship and provides compelling evidence that rising CO2 caused much of the global warming.
Lead author Jeremy Shakun, who conducted much of the research as a doctoral student at Oregon State University, said the key to understanding the role of CO2 is to reconstruct globally averaged temperature changes during the end of the last Ice Age, which contrasts with previous efforts that only compared local temperatures in Antarctica to carbon dioxide levels.
“Carbon dioxide has been suspected as an important factor in ending the last Ice Age, but its exact role has always been unclear because rising temperatures reflected in Antarctic ice cores came before rising levels of CO2,” said Shakun, who is a National Oceanic and Atmospheric Administration (NOAA) Post-doctoral Fellow at Harvard University and Columbia University.
“But if you reconstruct temperatures on a global scale – and not just examine Antarctic temperatures – it becomes apparent that the CO2 change slightly preceded much of the global warming, and this means the global greenhouse effect had an important role in driving up global temperatures and bringing the planet out of the last Ice Age,” Shakun added.
The good news about the paper is that they have provided the temperature records (Excel spreadsheet) for the 80 proxies used in the study. My compliments to them.
Me being a suspicious fellow, however, I figured “trust but verify”, so I plotted up the temperature records that they used. I always begin with the original data, without any additions or distractions. Figure 1 shows the data that they used.
Figure 1. Records and types of proxies used in the Shakun2012 study
As you can see, some of the ice core records are down where we’d expect them to be, well below zero. Those are the GRIP and NGRIP records from Greenland. But there are some oddities about these proxies.
One problem that is immediately obvious is the timing. The peaks for the previous interglacial period (the Eemian, about 130,000 BC) don’t line up. That may not be much of a problem, though, because the paper is about the warming from the most recent ice age.
One oddity is that there are ice core records that are right around freezing (0°C). In addition, there are pollen records around freezing as well. This shows that we actually have a mix of anomaly records and actual temperature records. This is not a problem, just an oddity.
Next, let’s take a look at the location of the proxies. Figure 2 is from their paper:
Figure 2. Location of the proxies used in the Shakun2012 study.
This looks good, it looks like there may be passable coverage. So let’s look at the last glacial transition, we’ll look at the time since 26,000 BC.
Figure 3. Same data as in Figure 1, but showing the warming from the last ice age.
Here, you can see the Antarctic ice core records (yellow and green lines near 0°C) mentioned above that are shown as variations, with the modern value taken to be 0°C.
Some other observations. Greenland (yellow temperatures at bottom) seems to be an outlier in terms of change in temperature. The Antarctic ice cores and all of the rest of the records show much less warming since the ice age.
In order to compare these eighty proxies to each other, what we need to do is to “standardize” them. This means to first subtract the mean (average) of each proxy from the individual values. Then each of the individual values is divided by the standard deviation of the entire record for that proxy. The result will vary between about -3 and 3. Standardizing preserves the shape and timing of the data, it just makes all the proxies have a mean of 0 and a standard deviation of 1.
Next comes the part that the authors of these multi-proxy studies seem to have generally ignored. This is to look at each and every one of these proxy records and think about what they seem to mean. I’ll look at them sixteen at a time. Figure 3 shows the first sixteen of the Shakun2012 proxies.
Figure 4. Proxies from the Shakur2012 study. All of these cover the period from 26,000 BC to 1980 AD. Vertical dashed lines show the minimum (light blue) and maximum (dark red) values for the each proxy. Minimum and maximum times rounded to nearest 100 years. Colors as shown in Figure 1. Click for larger version.
NOTES BY NUMBER
1, 2: These are the Greenland ice cores. They show a warming of 32 and 27 degrees respectively, which is much more than any other proxy. Warming begins earlier than 20,000 BC.
4: The warmest date is at 1200 AD.
6: Warmest date is 1000 AD. Warming doesn’t start until 12,600 BC.
9: Maximum warmth is at 14,600 BC.
15: Very unusual shape, 11° warming.
Figure 5. Same as Figure 4, proxies from the Shakur2012 study. All of these cover the period from 26,000 BC to 1980 AD. Vertical dashed lines show the minimum (light blue) and maximum (dark red) values for the each proxy. Minimum and maximum times rounded to nearest 100 years. Click for larger version.
19: Warming doesn’t start until 10,800 BC
21: Maximum warmth precedes maximum cold.
28. Maximum doesn’t occur until 400 BC.
30. Maximum doesn’t occur until 1400 AD.
31. Maximum doesn’t occur until 2400 BC.
32. Maximum doesn’t occur until 1500 AD.
Figure 6. Same as Figure 4. Click for larger version.
34: Maximum at 1600 AD
35: Maximum at 14,000 BC
36: Strange shape, constant warming until the present.
42. Maximum not until 400 AD.
44: Warming until the end of the record in 8200 BC.
Figure 7. Same as Figure 4. Click for larger version.
50: Maximum not until 1100 AD.
51: Constant rise beginning to end.
52: Large drop and rise after maximum warmth.
53: Rises beginning to end.
54: Rises beginning to end.
58: Maximum not until 1300 AD.
59: Maximum not until 1600 AD.
60: Large rise in 1100-1200
Figure 8. Same as Figure 4. Click for larger version.
67: Warming starts at 25,900 BC.
68: Warming only one tenth of a degree
76: Warming occurs almost instantaneously
Discussion
The variety in the shapes of these graphs is quite surprising. Yes, they’re all vaguely alike … but that’s about all.
The main curiosity about these, other than the wide variety of amounts of warming, is the different timing of the warming. In some proxies it starts in 25,000 BC, in others it starts in 15,000 BC. Sometimes the warming peaks as early as 14,000 BC, and sometimes around 5,000 BC or later. Sometimes the warming continues right up to the present.
The problem becomes evident when we plot all of these 80 standardized proxies together. Figure 9 shows all of the standardized temperature traces.
Figure 9. All 80 temperature proxies from Shakun2012. Colors as shown in Figure 1.
Now, there’s plenty of things of interest in there. It’s clear that there is warming since the last ice age. The median value for the warming is 4.3°C, although the range is quite wide.
But if you want to make the claim that CO2 precedes the warming?
I fear that this set of proxies is perfectly useless for that. How on earth could you claim anything about the timing of the warming from this group of proxies? It’s all over the map.
Final Conclusion
The reviewers should have taken the time to plot the proxies … but then, the authors should have taken the time to plot the proxies.
w.
[UPDATE] A hat tip to Jostein, who pointed in the comments to the Shakun Nature paper being available here.
[UPDATE] Some folks wanted to see the CO2 data they used on the same timescale. Other folks said the colors in Figure 9 were misleading, since ice cores were printed on top, obscuring others below. We’re a full-service website, so here’s both in one:
Figure 10. All proxies, along with CO2 record used in Shakun2012.
My best to all,
w.
I decided to take a look at the various proxies by proxy type. There are ten different kinds of proxies.
Figure 11. Proxies averaged by type.
A few notes, in no particular order. The ice core records are similar, but the timing is different.
Foram assemblages seem to be useless. The same is true of the Tex86 proxies.
Pollen has a consistent signal, but the warming doesn’t start until about 10,000 BC.
MBT/CBT perfectly exemplifies the problems with this approach. Which one are we supposed to believe? Which one is it that is lagging the CO2?
Finally, the Mg/Ca and the UK’37 proxies kinda sorta have the same shape, but no uniformity at all regarding the timing of the rise.
Let me close with a black-and-white version of the above chart. This allows you to see where the denser areas are located.
Figure 12. Proxies by type. Blue line shows CO2 data as used in the study.
Note the difference in the underlying shapes of the different types of proxies, and the differences in their timing with respect to the rise of CO2.
Next, note that the CO2 record they are using is from Antarctica. That is the reason for the good fit with the single “ice core ∂18O and dD” proxy (left graph, second row) and the “ice core dD” (center graph, second row). Both of those are Antarctic records as well.
Also, as you can see, even within each proxy type there is no unanimity regarding the timing of either the onset or the end of the warming from the last ice age.
CO2 is the blue line … so was the warming before or after the blue line?
w.
[UPDATE]—The discussion continues at Shakun Redux: Master tricksed us! I told you he was tricksy!
Brilliant as usual
The reviewers should have taken the time to plot the proxies … but then, the authors should have taken the time to plot the proxies.
=================================
Willis, there’s a good chance they don’t know how…..
….or it’s just more sloppy hurry up and publish rent seekers
I think I can see the face of Jesus in the Fig 9 plot! /sarc
Incredible work, Willis! Looking at the scatter plot, it seems the warming of that dotty mass of mess begins around 20k BC, which is before the CO2 raise.
In any case, this data is so all over the map, there’s no way to say anything about the order of timings. Maybe there’s a difference in timings based on the source of the proxie? But, when I look at say Mg/Ca, there you have some showing warming starting before 20k BC and some starting 15k BC. So even there it’s inconsistent…
Nice deconstruction, Willis. Are you working on the CO2 data as well?
April5, 2012
Climategate Heads to Court
By S. Fred Singer
http://www.americanthinker.com/2012/04/climategate_heads_to_court.html
As a climate scientist, I am quite familiar with the background facts that Prof Michael E. Mann (now at Penn State U) so shamelessly distorts in his new book The Hockey Stick and the Climate Wars: Dispatches from the Front Lines.
Can they really date these proxies to within 100 years or so, back to 12000BC? If not, then surely their whole case falls apart.
So which invidual proxies lag or lead the rise in CO2? Which cross over at some point?
Thanks again Willis!
“Final Conclusion
The reviewers should have taken the time to plot the proxies … but then, the authors should have taken the time to plot the proxies.
w.”
No, no Willis, the whole “International Antarctic Research Team” will be packing their bags for the last time now that they have been proven to be of no use whatsoever!??
Willis – Excellent deconstruction, as always. Wonderfully informative graphics. Tufte would be impressed.
How has Shakun responded to your analysis?
A little bit of smoke and mirrors and an unsubstantiated claim, but it was all that was needed to keep the msm on message. Keep asking the right questions Willis.
Seems that the authors and reviewers did more plodding than plotting.
Thank you, W, for taking the time to plot the proxies so us public have a better understanding of the data.
Al Gore was caught lying about this timing by British courts. Willis, It is my layman’s understanding that seawater, as it warms, releases CO2 dissolved therein. As seawater warms it’s ability to keep CO2 in solution decreases. This leaching of CO2 as the oceans warm is a great explanation for the correlation between temperature and atmospheric CO2 concentration. It explains why CO2 lags warming. Warming first then atmospheric CO2 increase.
This is provable in a laboratory. Yet no mention of it in this “Shakun2012” paper.
They definately stretched things a long way to make CO2 the culprit. Their data does not support their conclusion.
Anthony’s first post on Shakun2012 provoked a lot of non-analytical reaction. Thanks for this bit of analysis. It seems a more direct statement of conclusion of the study would be that the take they are emphasizing is only one way of looking at a bunch of proxies and any one way is a bit of a stretch due to the huge variance. This study doesn’t seem to move the debate as much today as it did when I first saw it.
Still stuck with subjective statistical analysis and a rule of non-empirical science that all ties and everything short of valid upset (upwards of 90% “certainty”) of a null hypothesis goes to the null hypothesis.
Willis,
Thank you once again for doing the due diligence the researchers and reviewers should have done on the first place. This is yet another example of the blinded leading the blinded and is so typical of the pseudoscience that is rampant in climate scientology.
The proxies that don’t support the CO2-causation meme are averaged out, or…
DE-PROXIED
Willis, once again thank you for being you. You use data to draw conclusions with no arm waving. You have not shown the carbon dioxide data but I agree that there is no way to draw any meaningful conclusion about the relative timing of temperature and carbon dioxide concentrations in the atmosphere from this data set.
I note an oddity in figure 9 at about -14000 years. The yellow (ice core) data quickly change, relatively speaking, down to minus 1.3 then up to plus 1.3 standard deviations. The same type thing happens at – 11000 years with an even wider swing. There is also another hint at – 26000 years. There was a geology paper about three years ago detailing a very rapid 10 to 15 F increase in one or two decades in Greenland about 14000 years ago. There must be some natural event that causes these departures in temperature. If carbon dioxide were the root cause, it seems to me it would take extreme volcanism, which would be well known from trace markers around the globe.
– It is hard to tell to much from figure 9 since proxies that were graphed later may obscure earlier ones. Not to mention that the yellow catches the eye.
– It looks like from -15000 to -8000 there was an accelerating increase. From -8000 on there was a slower decrease.
– If you averaged all the values for a time and then graphed the average would it show anything useful about the general trend of the data.
I would have liked to see the CO2 levels indicated on the final plotting. I think you also demonstrated that some of these proxies are in fact not proxies at all. On the other hand, the ice core proxies seem remarkably consistent. A bit of research into the accuracy of ice core proxies would be worthwhile.
Just more post-normal science (fit the data to the theory). Truly nothing to see here folks; run along.
(However, it is part and parcel in keeping with the CAGWCF (“Control Freaks”) meme they keep pitching.)
TRM said:
They definately stretched things a long way to make CO2 the culprit. Their data does not support their conclusion.
————————————————————————————————-
But in the world of AGW “Science” data says whatever they want it to say or it is adjusted accordingly. There hope that explains it for you.
cheers
PS can’t wait for the rebuttal adjusted data analysis. Say anyone want to bet on the chance of any of the above information ever seeing the pages of Nature?
Me being a suspicious fellow, however, I figured “trust but verify”
haha, these Global Warming nuts are even worse than the old Soviets though so you may have to ratchet up your level of suspicion to compensate
Would it be possible to superimpose CO2 (with error bars) for the same interval on top of the scatter plot? That would make a compelling image.
Willis, it’s reasonably easy to bring the WUWT final data-plot into excellent agreement with the main data-plot of Shakun2012:
Step 1: Color-code the WUWT time series into northern-and-southern hemisphere proxies, per Shakun2012’s figures 2B and S-28AB (the latter figure is in their 51-page Supplemental Information).
Step 2: Include the CO2 data, per Shakun2012 Figures 2A
————————
Summary: The WUWT/Eschenbach analysis of the temperature/CO2 data stands in good agreement with the Nature/Shakun article. In aggregate, the global data provide no evidence that temperature increases precede CO2 increases.
This reminds me of Steig et al 2009. The AGW fraudsters NEEDED the Antarctic to “warm” as per hysterical predictions. And abracadabra Eric Steig whipped some warming out of his hat. The news media breathlessly (and credulously) reported the study “results”. The study was soon shown to nothing more then an exercise of data manipulation, and proven to be one fantastical error after another. The authors claimed they were incompetent, not fraudulent, and the media promptly forgot the whole thing ever happened. Of course AGW supporters already had their headlines. This study has the same flavor.
You should know better than to suggest that a value is the “maximum” for a proxy without establishing the uncertainty. Thats the kind of crap I expect from Hansen and his temperature records.
I’d like to see the proxies they considered but discarded, because the ones they picked certainly don’t prove anything other than the interglacial started.
Nice post. Science should be “here’s what we know” Not “here’s what we want to conclude, and we’ll present the data in a manner to support our preconceived notions”.
We know it warmed, and you show that we have a hard time saying exactly when.
These proxies make me think of global warming data.
Lets say you are making hamburgers and you take 30% frozen ground beef (representing the cooling stations) and say 30% overcooked ground beef (representing the stations warming way more than .2C/decade) and then you take the 40% of the stations warming less than .2C/per decade.
Then you throw them all in a meat grinder.
Mosher would suggest the burgers are perfectly cooked.
The authors of this paper suggest the meat grinders proxies prove something about CO2 leading temperatures.
I wouldn’t.
LOL @ Steven Mosher
All of a sudden you are extolling the size of ‘uncertainty’ ? What a laugh. The fact is that in almost ALL surface station data as in proxy data, “uncertainly” and limits of observability are likely to be much larger than the ‘signal’ extracted.
I submit another vote to overlay the CO2 data on the final plot. Please.
Nice punchline, Willis. Too bad members of the orthodoxy are not allowed to think for themselves. They might save themselves some embarrassment.
I like Figure 9, it reminds me of a Rorschach Test. I can see what I am pre-disposed to seeing.
In my case, a vomited rainbow.
I thought all data was good, Steve.
@Mosher,
You are really overreacting here, and missing the entire point.
The maximum temperature for any of the plots isn’t under discussion, it’s the timing of when temperature starts to raise. And that’s scattered all over the place, refuting the conclusions of the paper that used this data, quite spectacularly.
Good post. Submit as a letter to Nature and see what happens. Send a copy to the authors. They’ll probably be mad that you posted it before alerting them, but maybe not.
Willis your Maunchasen by proxy allusion makes me sick! (I think perhaps Willis and about a 1/2 dozen people are laughing now…)
I’m the happiest sick relative you have…!
Max
Willis. Great work as usual. Your Figure 1 and Figure 3 show just how noisy these proxies can be. I’m not sure that minimums and maximums mean anything given the noise levels of each proxy. But there is a definite cool to warm trend and it would be interesting to calculate the inflection point of this trend for each proxy, to then take the average inflection time and subtract each from the average to see how variable the time of transition from cool to warm is for each proxy. If, for example, they vary by many centuries, then how could you possibly rely on them for a correlation with a lag time with CO2.
What bothers me about the proxies is the variation in transition time from cool to warm. Proxy 67 shows a gradual warming over thousands of years while proxy 76 shows a shorter transition over centuries. Proxy 73 is garbage as are many more, making Figure 2 (location map) misleading.
Figure 9 is a bit tough to appreciate. Perhaps if all the points had the same color people would realize how much error there is in the data sets.
But thanks again Willis for showing us how ugly the raw data is. GI = GO.
Steven Mosher: You should know better than to suggest that a value is the “maximum” for a proxy without establishing the uncertainty. Thats the kind of crap I expect from Hansen and his temperature records.
That’s a fair comment. You beat me to it. Establishing “maxima” by eyeballing and contrasting them does not show that much. When the paper comes out from behind the paywall, we’ll be able to compare Willis’s methods to the authors’ methods in detail.
Also, it is good that the authors provided their full data set.
To amend my previous post, Willis should probably obtain a copy of the paper from the authors before submitting a letter to Nature, assuming he has any interest at all in my suggestion.
My first reaction to the study (I have no vested interest in assuming a major role for CO2 in climate changes): what if a large portion of added (sun) heat was being initially sequestered deep into oceans (as per the current Trenberth theories), releasing great quantities of CO2 in the process. This “sequestered’ heat would eventually make to the surface at different times, different places depending on the ocean currents of the time, which was the main driver of local temperatures around the globe. It seems more plausible to me that atmospheric temperatures around the world would be impacted primarily by changes in surface water temperatures than changes in CO2 concentration although the additional CO2 acted as a positive feedback. I think the study (minus the misdirected hype) will ultimately have a positive effect on science. It’s great to have more data since it only confirms what others have been saying years that causes of climate changes are rather complex.
Steven, as an educational service for the WUWT readership, could you provide us with a high level description as to what kind of methodology should be used to establish the uncertainty?
How would uncertainty be defined in precise terms? What kinds of factors — statistical factors, systematic measurement error factors, and physical science factors — would go into establishing the uncertainty? What kind of approach would be employed to integrate these various factors in ways which can reliably establish an uncertainty?
“Next, let’s take a look at the location of the proxies. ”
Probably just a curiosity, but what I immediately noticed was, other than ice cores, they’re all coastal locations (a few mid-Atlantic?).
Why does the eyeball trend of the scattergram appear to be heading down since around 8000 BP? I thought temps were rising since the deglaciation?
The warming arguably begins in 15,000 BCE, but, as you so brilliantly point out, it is all over the map, all over the map. If there was one unifying observation one could draw from the holocene part of the data, it is the holocene optimum occurred roughly 8000 years ago, which corresponds well to the last time the sun was as active as it was in the 20th century, at least according to some of the papers I’ve read. But not Leif, apparently.
rgb
“The reviewers should have taken the time to plot the proxies … but then, the authors should have taken the time to plot the proxies.”
I’m sure they are working on it.
Or they did but realized the results were not useful so they told themselves “never mind” with that stuff, we have a story to tell”.
Munchausen Syndrome by Proxy? Careful – you’re banging on hornet nests!
The New Hampshire Child Protective Services agency (DCYF) has tried alleging that against some of my wife’s clients. (Or conversely, ignore a diagnosis of Osteogenesis Imperfecta.) MSBP is something where the mother (they have different attacks for the fathers) makes the kid sick so she can look like a hero when she gets medical treatment for the kid.
I guess in the climate “science” arena, the closest analog would be alarmists convincing everyone that we are destroying the environment so the can look like heroes when alternative energy, green power, and a return to the 18th century saves the day.
There’s MAMA, Mothers Against Munchausen Syndrome by Proxy Allegations. Perhaps we can get Anthony to rename this blog WUWU – Watts Up with Unknowns.
“It’s clear that there is warming since the last ice age. ”
Is this an unexpected result?
One way to solve the matter of who is the best proxy, when you have that many data points, statistics can provide some relief.
I took the mean of all of the maximum times. I had to read from the graphs, so I am ± 500 years.
The mean ± sd is 6255 ± 3501
The median is 6000
So, one way to arrive at a better figure is to discard all values greater than 2 sd.
This is a good way to assess the good v. bad players on this value alone. I did not have time to do minimum time, but this could sort out a couple more outliers.
Let’s see if this passes some muster!
Thank you!! and nuts to the reviewers.
Those values should be -6255 and -6000 yrs BP, of course.
Ouch—bad grammar in my first sentence. Too much phone texting.
Obviously, all you need to do to arrive at an exact record of global temperatures is average all the proxy results. As the IPCC has demonstrated so well, no single result can be trusted, but all the untrustworthy results can be made trusty by taking an average. (sarc)
so the arctic warmed first and released the CO2.
no surprise the colder water and ice have the most dissolved gases, is it?
“Dr. Munchausen”. Hilarious!
At -12,500 am I seeing a sudden drop, then surge back up again?
Please note that my method is not fair for the most recent maxima. This is because ± 2 sd puts anyone below 6000 YBP into the future, so all 6000 BP or less values come out kosher by this quick and dirty test. This is because the distribution is heteroskedastic, meaning not a uniform Gaussian curve because of the time limit.
One thing is certain from the proxies. The peak temperature after the glaciation is quite some time ago (6000 YBP)—that is a surprise to me.
Steven Mosher says:
April 6, 2012 at 9:23 am
Say what? First, I’ve drawn lines through the maximums and minimums, so that you can use your eyeballs to determine the uncertainty.
Second, having no information about the errors in the datasets, it is not possible to put accurate error bars on the maximum or the minimum values.
Finally, my conclusions don’t depend in any way on where the maximums and the minimums are. I have plotted them for your information, so you can use your eyeballs to see the differences in the timing of the warming.
Seems like lately, sometimes you’re just objecting to object … hows about turning your fine analytical mind to objecting about the shabby kind of science represented by the Shakur paper?
w.
Did anybody actually read the article? I concluded from the abstract and the comments by the coauthor that they never actually say that the atmospheric increase in CO2 precedes the increase in T. Quite the opposite. They suggests that due to changes in the earth woble the oceans, in particular the southern oceans, warm up. Then, using their favourite feedback from increasing CO2, the rest of the major warming occurs. Nothing new here, warming occurs first, then CO2 increases, as anticipated. The only thing they might have tried to do is obfuscate the icecore data, spread out the warming over 7000 years rather then accepting a rather sudden increase as suggested by icecore data, and putting the amount of initial warming up for debate.
Looking at the wide spread of T increases from the proxy data, it is obvious that a precise timing using proxydata is impossible. The advantage of the icecore data is that even if one does believe that the timing might have an error bar, sequentially the CO2 follows the increse in T.
Downdraft says:
April 6, 2012 at 10:42 am
Obviously, all you need to do to arrive at an exact record of global temperatures is average all the proxy results.
Your point is not wrong, even if you sarced it!
Statistics says, that if you have enough sloppy measurers, the mean (not average) with the st.dev. is a more reliable result than the single number measured by the best measurer. Hard to conceptualize that, I know! Yet it is true science.
Interesting analysis, but another question occurs to me: Isn’t the very notion of reconstructing a “global average temperature” from such a disparate set of proxies (which, I suspect, have never been rigorously studied for their tendency to agree or disagree with each other) laughable?
Oakwood says:
April 6, 2012 at 9:42 am
I didn’t overlay it for several reasons.
One is that they have released their temperature data, but not their CO2 data, so I was unwilling to mix apples and oranges.
The second is that, no matter where you put the CO2 in that pile of nonsense, it won’t make a difference.
The third is that, as near as I can tell, they’ve looked at eighty temperature records and are comparing them to a single CO2 record. This is an ice core record from the EPICA ice core, which they say has “recently been placed on a more accurate timescale.” That seemed curious, they are averaging 80 proxies for historical temperature, but they’ve taken a single proxy for CO2.
In any case, I’ll do the overlay when I get a few moments. I’ll have to digitize the CO2 data they used, so it may be a day or so.
w.
Averroes says:
April 6, 2012 at 9:21 am
….
Summary: The WUWT/Eschenbach analysis of the temperature/CO2 data stands in good agreement with the Nature/Shakun article. In aggregate, the global data provide no evidence that temperature increases precede CO2 increases.
Not really. The data series which are usually referenced as showing that warming precedes CO2 increases are typically the ice core data from Antarctica – especially the Vostok core – and Greenland cores.
What Willis demonstrated is that by mixing apples and oranges, liverwurst and lettuce, sand and gravel, as the authors of the original article did, you don’t get fruit salad, which is what the original authors claim. At the most simplistic level, it is obvious to anyone who can tell a hawk from a handsaw that if you add two proxies together – say pollen and ice cores – with inferred maximum “temperatures” that fall within the last 2,000 years and in the early Holocene respectively, the mean date of the maximum temperature of the two proxies will be later than the earliest date, earlier than the latest date, and in fact, the new “maximum” tells us little other than the two proxies don’t behave the same. In fact, it seems obvious that one or both “proxies” may not be the useful proxies of temperature that one might hope.
What the authors seem to have done is broaden their selection of proxy types until the resolution of the resulting “time” series was hopelessly diluted. Then they claimed that they found no support for the idea that temperature increases preceded atmospheric-CO2 increases. In fact, (by tossing as many wildly varying forms of proxy in to the mix as they could find) they assert that CO2 increases preceded global warming.
Septic Matthew/Matthew R Marler says:
April 6, 2012 at 9:58 am
No, it’s not a “fair comment”. It’s the kind of crap I expect from Hansen and his ilk. It is peripheral nitpicking on a meaningless issue.
Next, I didn’t establish maxima and minima “by eyeball”. Is my writing that hard to fathom? Those are the years with the highest and lowest data points. That’s why they are called “maxima” and “minima”.
Finally, so what? How would establishing some kind of error bars on the maxima and minima advance our understanding in the slightest? The analysis works perfectly without even considering maxima and minima, it’s extra information.
Indeed, they have my appreciation for that.
I have a copy of the paper, and have had one since a day or so after it came out. What’s your point?
w.
Looks like one of those art works they make by loading a shotgun with paint.
Willis
Personally, I think you have ‘substantial evidence’ for your hypothesis and consequently you don’t need to provide any further information at all.
tonyb
Per previous requests, here is the Shakun temperature data, with the CO2 data overlaid on it …
I’ve added this to the head post.
w.
When I buy a jigsaw puzzle I digitally scan the pieces to produce a Cartesian coordinate readout for each on a mm scale. Then I make the necessary transformations to digitally compare the sides of each in all possible combinations, making fits accordingly. I find this saves much time over eyeballing it.
As most know, the great advantage of the ice cores is that multiple data are contained in close proximity in the ice. CO2 is locked in within a century or two of snowing, and the lag can be estimated and accounted for. So mixing in other proxies can only obfuscate. But the interesting thing is, a doctoral candidate already employed by the govt comes up with a study tailor made to counter scientific skepticism–by way of junk science, it seems. This shows how much progress you guys have brought about: the propaganda war is moving away from name calling toward spurious rebuttals of legitiate skepticism. Good work! –AGF
I see what you are trying to do, but is it really fair to directly compare different types of proxies and say that they can’t be used because they aren’t similar?
I really think you need to take into account that different proxies actually measure different things. Each of them can give you some indication of temperature, but each of them also has signals from other factors. Also, each of them actually measures diffent temperatures. For example, ocean sediments generally give upper ocean temperature. Some isotope proxies give upper troposphere temperatures (where rain forms) rather than surface temperature, etc.
A simple numerical evaluation, such as the one you have done here, has some value but don’t place too much importance in that type of oversimplified analysis.
Where does their data CO2 come from? It needs to come from an area representative of the temperature data. If they’re just using icecores, it takes quite some time for the co2 to mix and bring the measurement up.
How do CO2 levels measured at greenland and antarctica compare to RoW?
Off topic but I just saw this bumper sticker in town: “Everything I need to know I learned from Ranger Rick.”
Willis, that new data-plot is a considerable improvement!
Now if you color-coded the proxy data’s geographic origin … such that “more red” meant “farther north” … and “more blue” meant “farther south” … then you might find that the independent Willis/WUWT analysis pretty solidly confirms the Shakun et al analysis.
This would be a very substantial step toward reconciling skepticism with science … already your independent analysis has gone far in this direction … now is a good time to go further.
One location for CO2 = good.
One location for temperature = bad.
Without reading the whole lot, sorry, priorities, but there is another mega problem comparing dates of records. They are often not independent. A lot of dating happens by fitting curves, compared to other proxies, wiggle matching.
Apart from that. maybe proxies aren’t that good either. See this little essay about Siberia during the Last Glacial Maximum:
http://dl.dropbox.com/u/22026080/Last%20Glacial%20Maximum%20in%20Siberia.doc
Excellent work, CO2 driving temperature is a ridiculous idea, it makes more sense that energy input drives the processes of the rise and fall of CO2 whether or not if it’s recorded as an ice proxy. It’s a Crank science Fail. Good man Willis.
aaron says:
April 6, 2012 at 12:10 pm
Good questions. From the paper
Next, you ask:
Quite similar, but with less annual swing.
The red band shows the approximate latitude of Mauna Loa, where the longest CO2 record is taken.
w.
Well done Willis. When I read in their paper about “… potential physical explanations for the correlations between temperature, CO2 concentration and AMOC variability in three transient simulations of the last deglaciation…” I started wondering about the purpose of all this verbiage. Climate simulations as far as I go have been losers and I certainly can’t check any of this stuff myself. After more unnecessary verbiage about “Uncertainty analysis” and “Robustnes of results” I realized it was meant to ease us into a belief that they have discovered something big: carbon dioxide did not follow but preceded end-Pleistocene warming. I never would have guessed it from their graphs. It is clear that this paper, as all others emanating from the climate establishment, takes it as a matter of faith that any observed warming is caused by the enhanced greenhouse effect of carbon dioxide and then attempts to prove it. There is just this one problem with their assumption: the chief greenhouse gas on earth is not carbon dioxide but water vapor. They both absorb outgoing infrared (long-wave) radiation and it is their combined absorption of radiant energy that causes the atmosphere to get warm. But now consider this: when we don’t change the amount of carbon dioxide in the air we have a stable climate. There are local temperature and humidity variations, to be sure, but long-term drift is absent. What guarantees this? To prevent a long term temperature drift the IR absorption by greenhouse gas concentration that determines IR transmittance of the atmosphere must respond to any such temperature drift. And water vapor is the only greenhouse gas that can easily do that. Starting from this qualitative picture Ferenc Miskolczi brought in radiation theory and showed that for a stable climate to exist the optical thickness of the atmosphere in the infrared had to have a value of 1.86 (15% transmittance). This transmittance is determined by the combined absorption of infrared radiation by all the greenhouse gases present, but the adjustment is maintained by water vapor, the only adjustable greenhouse gas in the lot. The blogosphere was hostile to the idea because it wiped out the sacrosanct Arrhenius law. But Miskolczi went on to test it using NOAA database of weather balloon observations that goes back to 1948. He found that the IR transmittance of the atmosphere had been constant for the previous 61 years as his theory predicted (E&E 21(4):243-262, 2010). During that same period of time the amount of carbon dioxide in air increased by 21.6 percent. This means that the addition of all this carbon dioxide to air had no effect whatsoever upon the absorption of IR by the atmosphere. And no absorption means no greenhouse effect, case closed. This is an empirical observation, not derived from any theory, and it overrides any theoretical calculations that do not agree with it. Specifically, it overrides any calculations based on climate models that use the greenhouse effect to predict warming. In accord with this, a close examination of the temperature history of the last 100 years reveals that there has been no greenhouse warming at all during this entire period. Starting with the twentieth century, the first part of the twentieth century warming started in 1910 and stopped in 1940. There was no corresponding increase of carbon dioxide at the beginning of this warming which means that according to the laws of physics it cannot be greenhouse warming. Bjørn Lomborg attributes this warming to solar influence and I agree with him. There was no warming in the fifties, sixties, and seventies while carbon dioxide relentlessly increased. There is no satisfactory explanation for this lack of warming, only various contorted excuses to explain it away. The true reason for this lack of warming is clear from Miskolczi’s work. There was no warming in the eighties and nineties either according to the satellite temperature measurements. There was only a short spurt of warming between 1998 and 2002 caused by the warm water that the super El Nino of 1998 had carried across the ocean. And there was no warming from that point on to the present while carbon dioxide just kept on going up on its merry way. And if you still think Arctic warming proves the existence of greenhouse warming think again: Arctic warming is not greenhouse warming either and is caused by Atlantic Ocean currents carrying warm Gulf Stream water into the Arctic (E&E 22(8):1067-1083, 2011). Taking all this history and Miskolczi’s theory into account the attempt of this Nature article to explain the end-Pleistocene warming as greenhouse warming is nothing more than hopelessly misguided global warming doctrine.
REPLY: Try learning about the revolutionary new feature: PARAGRAPHS
– Anthony
Willis Eschenbach says:
April 6, 2012 at 10:54 am
Steven Mosher says:
April 6, 2012 at 9:23 am
======================================
Willis, do not expect a reply from Mr Mosher. Pendantic hit and run comment, no engagement in a real consversation, as if he is above such petty dialogue, this is what I expect from him lately.
“Shakun all over!”
Great work Willis.
I came to the same conclusion several days ago and posted: “Shakun et al is highly improbable.”
http://wattsupwiththat.com/2012/04/04/a-new-paper-in-nature-suggests-co2-leads-temperature-but-has-some-serious-problems/#comment-945861
Mind you, I did not crunch the numbers.
Instead, I employed basic principles, namely the tried and trusted “Law of Warmist BS”:
“You can save yourselves a lot of time, and generally be correct, by simply assuming that EVERY SCARY PREDICTION the global warming alarmists express is FALSE.”
Genesis of this new Law of (Human) Nature is outlined at:
http://wattsupwiththat.com/2012/02/28/the-gleick-tragedy/#more-57881
One problem with all the ice cores is that the CO2 data is very sporadic. You can see the ‘holes’ in Willis’ CO2 graph. I tried some time ago to get a handle on which came first by looking at the second derivatives, but failed because the CO2 data is sparse – far sparser than the temperature proxy data. I also found that it makes a huge difference where you start normalizing, because that can change the apparent zero, and if the normalized zeroes of the temperature and CO2 differ, then the leader will change position, and become the apparent follower!
@agfosterjr
‘
I bet you’re a bundle of laughs at parties 🙁
For me WUWT is an education. This is an excellent, painstaking and essential review. I suspect Shakun et al. is the kind of paper that the IPCC would be looking to include in its 5th Assessment Report. Perhaps now they won’t be able to.
Nice piece of work if the temperatures are plotted the right way. Always interested in factual evidence.
How science should be done!
One cannot conclude anything from these datasets. Besides Shakun used different proxies. Different proxies give different results as proven in piece above.
Conclusion: Proxydata are nothing more than an estimation of what happened. They tell you nothing about the actual temperatures or concentration levels of certain gases from a specific period in time.
A good example is this one on the Greenland Ice Core (GISP2):
http://hot-topic.co.nz/easterbrooks-wrong-again/
If you take a look at graph 4 and 5 it is obvious that the anomalous temperatures from the last 170 years are higher than what happened in the last 10.000 years. It is agreed that the MWP was as warm, warmer of slightly colder than 20th century temperatures.
And we can detect the MWP (1000 years ago) in graph 5. Also take a look at the discrepancy between actual temperature data and ice-core data in graph 5 as well.
According to Richard Alley ice-cores are the gold standard in proxies. Yeah…Right!
I see what you’re saying, which I think is that the spread in time of the proxy data appears to be too great to allow a determination of whether the temperature increase precedes or succeeds the increase in the CO2 data. But there are statistical techniques that allow a quantification of how likely it is that the increase in CO2 precedes the increase in the proxies, based on the these data. So I think it’s a bit harsh to state that these data are perfectly useless for this purpose.
“When I buy a jigsaw puzzle I digitally scan the pieces to produce a Cartesian coordinate readout for each on a mm scale. Then I make the necessary transformations to digitally compare the sides of each in all possible combinations, making fits accordingly. I find this saves much time over eyeballing it.
I bet you’re a bundle of laughs at parties :-(”
Any time I see a jigsaw puzzle on a table I take one non-edge piece, sneak it into my pocket when nobody is looking, and walk away.
Willis Eschenbach: Those are the years with the highest and lowest data points.
If you wrote that, I missed it.
I have a copy of the paper, and have had one since a day or so after it came out. What’s your point?
My first point was that you should submit this as a letter to the editor of Nature. It’s a chore you might not like to take up, but your post here makes a good point well: if there is evidence that CO2 increase preceded temperature increase, that evidence is hard to see. Only the abstract was posted, and until you wrote in response to me, I did not know you had the whole paper (though I did wonder how you had obtained the data without the whole paper.) Maybe “it goes without saying” that you would not critique a paper from its abstract, but I am a dunce and I never get what goes without saying properly. I expected that you’d link an unpaywalled copy of the paper if you had it.
Back to highest and lowest data points. Assuming for the sake of argument that all of the time series are measures of some underlying process (plus other stuff) what you want is something like the maximum and minimum of the underlying process, or the inflection points of the underlying process, or things like that. The maxima and minima of the individual records don’t give that. The data hint strongly (or shout loudly) that estimates of such quantities are likely to have large variances. My following comment, that your method should be compared to the method of the authors, omitted my guess that the original authors had even less than you presented relevant to their case. It was a response to Steven Mosher’s implied (or at least inferred by me) point that you had supplied a less reliable analysis than the authors, since he critiqued you but not them.
Oh. I see I ought to have read Anthony’s post on the paper first.
Excellent Willis.
I’ve read various claims that CO2 follows temperature, variously by 300 to 800 years. Are these claims equally questionable ?
There is certainly a very weak link in this paper when it claims that a 0.3degree change results in a sufficient outgassing of carbon dioxide from the Southern Ocean to ultimately increase CO2 by about 100ppm. That’s certainly an hypothesis that can be tested against solubility, but I don’t think that’s even necessary. If it were true, then the CO2 concentration in today’s atmosphere, after a SH warmup of about 0.5deg, would be rising much more rapidly than indicated by mere emissions, and the fractional increase in the atmosphere would be traceable to a decrease in the southern ocean.
The subsidiary hypothesis that the CO2 was released because of a sudden change in SH sea ice is also very speculative. Given the nature of the Southern Ocean, it surely could not have extended the very large distance further north than it is today, to make this a mechanism.
This paper certainly creates a lot more questions than it answers.
bubbagyro says:
April 6, 2012 at 10:56 am
Downdraft says:
April 6, 2012 at 10:42 am
Obviously, all you need to do to arrive at an exact record of global temperatures is average all the proxy results.
Your point is not wrong, even if you sarced it!
Statistics says, that if you have enough sloppy measurers, the mean (not average) with the st.dev. is a more reliable result than the single number measured by the best measurer. Hard to conceptualize that, I know! Yet it is true science.
Well, not exactly. In this particular case it has to be a weighted average. The sites are not determined by a random statistical process (like generating a random point from a uniform surface distribution) and then finding a proxy at that point. Rather, there are some places on the Earth’s surface where, for better or worse, some sort of proxy of earlier temperatures is supposedly preserved. Since that is generally not true at arbitrary locations, one has to take what one can get.
Those locations are drawn from an environment that we know was not homogeneous (and this is of course immediately apparent in the data). In particular, there is a very clear latitudinal structure, as we might expect, but with surprises like Greenland that confound any simple rule we might use to relate a local measurement to a smooth function of expected temperature variation by latitude. However, beyond that we know perfectly well that temperatures on a seashore are often terribly correlated with interior/mainland temperatures, sometimes interior temperatures drawn from just a few miles away. San Francisco is a marvelous example — you can have multidegree differences in average temperature drawn from sites separated by a hill inside the city, let alone the temperatures drawn from coastal sites compared to sites ten or twenty miles inland. In other words, all of the problems we have now with GISS and HadCRUT, except that we have only a tiny handful of samples, we have no knowledge whatsoever about the moral equivalent of “UHI” effects (local environmental deviations from even a local thermal average because a site happens to be on what was a southwest facing hill 12,000 years ago until a major earthquake rearranged the landscape so now it faces north). Finally, because we are averaging on a sphere there is the eternal problem of the Jacobean.
Now a glance at the coverage map Willis placed up at the top reveals major problems. First of all, it looks like around 90% of the sites are coastal. Whoa, huge problem. Surface to perimeter of the continents being what it is, this means that nearly all of the land surface area remains unsampled. Indeed, areas omitted include things like “all of Asia” (except for enormous oversampling of coastal regions and islands, e.g. Japan) — what’s up with that? Coastal sites are the worst possible sites to sample, as they are buffered by the ocean and fail to show the full variability of the climate elsewhere, even elsewhere a very short distance away.
Second, although it is difficult for me to tell for sure on the 2D map provided, it looks like the coverage oversamples the poles compared to the tropics. I know, it is difficult to be sure, because one cannot see it very clearly, but there is a lot more area in a given latitudinal band near the equator than there is near the poles, and — did you notice the lack of samples from this thing called “the pacific ocean”, which covers a mere 1/2 of the planet, except for oversampled clusters at a few specific locations on its perimeter?
I do agree that one learns something by just averaging the renormalized data together, especially if one smooths the average laterally in time as well as vertically across the samples, but what one ends up with is not a valid estimate of any sort of global temperature or global anomaly. Rather it is a curve that one hopes is somehow a monotonic function of the global temperature and/or global thermal variation across the time frame in question.
If I wanted to turn this into an actual estimate of global temperature — presuming that one had the slightest hope of normalizing proxy data to an actual temperature scale at even 2-3K precision — I would absolutely not do a flat average. I might do a flat average of Japan — otherwise absurdly overrepresented and then weight Japan alone with a factor (ideally an empirically determined parameter) that I might hope is its correlation function with local areal temperatures — in other words to the extent that temperatures in Japan are predictors of temperatures in mid-China, one might create a reverse projection (with a very large error bar, obviously) to assign a very weakly weighted estimate of the probable temperatures in the unsampled place from the sampled place.
Ditto the other sites. For example, there appears to be a sample from or near the North Carolina Coast. The Coast is a lousy proxy for the interior. For one thing, it is 2-4K warmer, on average, in the winter, and 2-4K cooler, on average, in the summer. It is often sweltering in Durham but delightful — a full 10F — cooler at Beaufort when I teach there in the summer. In Durham we can have frost and snow in the winter, but palms and beaugenvillias and oleanders thrive in Beaufort. Durham isn’t a good proxy for Chapel Hill — the latter is on a hill where spring comes sooner but the summer stays a bit cooler. Neither is great for the Smoky Mountains or Appalachians or for the coastal plains. The sandhills trap and release water differently from the piedmont differently from the mountains differently from the oceanic moisture on the coast so the patterns of precipitation are different across the state. And this is just one state — go over the mountains into Ohio, go west to Kansas — just how good is that NC coastal proxy going to be at predicting the temperature — or even just the temperature variation — in Kansas? A change in patterns of prevailing wind over the 15,000 years of the proxies is enough to completely erase any modern correlations and replace them with something entirely different. A change in ocean currents would be far worse, and just such a change is supposed to have occurred and been involved in the Younger Dryas.
Speaking of which, just where did the Younger Dryas go? There it is, big as day in the antarctic ice cores, unmistakable and huge. Yet it completely disappears in the dot-o-gram of the collective data. Was the YD an antarctic polar event? I didn’t think so, but this data seems to more or less erase it elsewhere. This is perhaps not surprising, given that so much of the data is coastal and thermally buffered, but given the clear trace of the YD on the land — where it is correlated with things like severe drought and dust storms on the NA continent, clearly visible as sedimentation layers the gully walls of streams not far from my house — this means that it is a terrible proxy for climate elsewhere.
The point is that, with care, one might be able to do something with the data, but the data raises far more question than it answers. I remain unconvinced by the assertions that axial precession plus orbital resonance plus a touch of magic are responsible for the bistability of the Earth’s climate. Perhaps all of these contribute, but they were all present four or five million years ago more or less as they are today, but the Earth was stably warm in spite of it. Until we really know what went on to alter this and create the bistability, assigning a cause (set) to the warming that started 15000 years ago, trying to resolve CO_2 from the multiplicity of causes or contributing agencies is absurd. And in the end, the data needs to make sense. This dataset is not senseless, but it is filled with puzzles far more than it provides answers.
rgb
agfosterjr says:
April 6, 2012 at 11:56 am
When I buy a jigsaw puzzle I digitally scan the pieces to produce a Cartesian coordinate readout for each on a mm scale. Then I make the necessary transformations to digitally compare the sides of each in all possible combinations, making fits accordingly. I find this saves much time over eyeballing it.
xxxxxxxxxxxxxxxxxxxx
Ha ha ha ya mean you cheat?
Willis:
I admire your breadth and depth of knowledge and data analyses. Hang in there, the yip yappers can find a tiny fault here and there but I have not seen anyone yet that can refute your conclutions in any of your articles. I hope for many, many more of yoru articles. Kudos and bravo!
Great work, and good discussions.
As a scientist, I find it devastating to see what the scientific establishment has come to. Eventually Science, and facts, will win out.
Willis. I downloaded the data. Thanks for making it so easy.
1. The yr BP column starts at zero and is positive increasing with points every 15-30 years. So I made the column negative (e.g. =-B1 etc).
2. I plotted Temperature versus yr BP for NGRIP (Greenland) and Vostok (Antarctica).
3. Temperature for NGRIP was fairly constant until -14,750 BP when it suddenly jumped higher (over a ~400 year period).
4. Temperature for Vostok was fairly constant until -16,808 BP when it started a gradual but continuous rise (over ~5,500 years).
From these two graphs it would seem that temperatures in the Antarctic started to rise 2,000 years before the Arctic and that the temperature change in the Arctic was both later and more abrupt.
Isn’t this contrary to the paper’s claims that the Arctic warmed first, melting the northern ice sheets, which stopped the conveyor belt, which warmed the southern oceans, which led to a CO2 increase in the atmosphere, which led to warming of the Antarctic? Even the raw data would seem to refute this theory.
bubbagyro says:
April 6, 2012 at 10:56 am
Statistics says, that if you have enough sloppy measurers, the mean (not average) with the st.dev. is a more reliable result than the single number measured by the best measurer. Hard to conceptualize that, I know! Yet it is true science.
In applying the rules of statistics properly there is more to say here. Your statement in my opinion only holds, if the measurements are about the same phenomenon and done with the same or comparable methods and units. This has to be so in order for the data to be open for meaningful statistical analysis in the first place.
You can do a perfect statistical analysis of bogus data. Whatever the result, it has no practical scientific value.
You could try running a “Kernel Smoother” over the pseudo-temperature data (the black dots in the last figure) to obtain a single black line from the data which would illustrate more clearly whether the black dots are leading or lagging the red dots.
http://en.wikipedia.org/wiki/Kernel_smoother
I spent two hours trying to make sense of that last graphic, then all of a sudden the dots resolved into an image Of Hansen’s face. It was a sublime moment.
Hi Willis, the dip in temperature at 11.7 Ky is also present in the levels of CH4, N2O and CO2 in the Antarctic. The log(dust) levels give a very good correlation with the line shape of these data, and there is a rather nice change in dust radius.
The Fe levels fall away at 17 Ky. No Fe in the oceans, less biotic, more CO2.
Gary Swift says (April 6, 2012 at 1:26 pm)
“Any time I see a jigsaw puzzle on a table I take one non-edge piece, sneak it into my pocket when nobody is looking, and walk away.”
——————-
So *you’re* the one!
Wow! All this data manipulation for free! And lots of info to allow evaluation too.
The Shakur article is behind a paywall and lacks some of the info to verify the implied conclusion. Eschenbach may be “wrong” but his effort is straight-forward, informative and sort of “testable”. May be that Shakur is better than the obscured view indicates, but obscuring the thing usually means it won’t hold up to serious scutiny. I’ll take Eschenbach and his efforts.
Thanks.
David A says:
April 6, 2012 at 12:35 pm
Mosh is a friend of mine in real life, but his posting habits drive me spare … which may be the point, I don’t know. In any case, he’s one of the good guys in my book so I cut him slack.
w.
MDR says:
April 6, 2012 at 1:24 pm
No, there is no such statistical technique. You can’t create meaningful answers when range in the proxies goes from the floor to the ceiling.
And although you could use statistics to say that for example the CO2 started upwards before the rise of 46% of these proxies … so what? That would show exactly nothing. The proxies are so varied, you can get any answer you want just by picking the proxies you want.
w.
BradProp1 says:
April 6, 2012 at 8:18 am
I think I can see the face of Jesus in the Fig 9 plot! /sarc
All I see is Osama Bin Laden peeping out (he’s between 1 and -1, about -22,000 to -20,000, blue face and turban with a purplie beard)
I’m normally a fan of your posts,but you are showing your bias with your commentry on only the maxminums and trends.
The question is wether CO2 rises proceed temperature rises, so the minimum commentry is much more important, i.e. does temperature reach a minimum before CO2 or vice versa, and you need to look at all available cycles not just the latest to avoid cherry picking.
I’ve not payed for the paper so I can’t really comment on their analysis, but it would seem taking it at face value and from what was already known, that temperature rises in the Antarctic first which then leads to rises in CO2 and then one of those two effects leads to rises in temperature elsewhere.
So not much change on earlier results, except more doubt on the cause?
Septic Matthew/Matthew R Marler says:
April 6, 2012 at 1:36 pm
I thought about doing that. Ideally what I would like to get are the inflection points, where it starts to run up, and where it ends.
So I figured, well, take the trend for say a thousand years ahead of and behind each point, that should do it. But then I realized that the variation in sampling rate is huge, so I’d have to first calculate how many points to include …
Then I looked at proxies like say #4 and #11 and a bunch more, and I thought “no way”. So I just took the maximum and minimum and SHOWED THEM ON THE GRAPH.
With that information, you can look at the individual proxy and try to understand what it is doing. It was something I added at the end of the analysis, to provide some unequivocal anchor points in a sea of strange proxies. It was included as a guide rather than a conclusion.
Finally, the “Warming = ” data was calculated by taking a centered 5-point average around the high and low records, and subtracting one from the other.
w.
Dr Burns says:
April 6, 2012 at 1:52 pm
The ice core data has been used for this in the past. If you take the air in a bubble in the ice core you can measure the CO2 as well as the ∂18O simultaneously. That gives a much more stable platform from which to do your analysis.
It is from that type of analysis that scientists have claimed that the CO2 follows temperature.
What I’m seeing from these proxies is that we don’t know as much as I thought we did about the shape and timing of the emergence from the last ice age. The other proxies tell a very different story from the ice cores …
w.
We are the experiment.
Longevity is ever increasing.
Some, are running out of others money to spend, fu*k them.
REPLY: Try learning about the revolutionary new feature: PARAGRAPHS – Anthony
Hey Anthony, you grammarian. First you won’t post my article because I had sentences ending in exclamation points. Now you want PARAGRAPHS too. Is it you or your name sake the Oxford don reading these comments? AA
Very nice work by Willis. Again.
I’d say it was a useful piece of work by Shakun. It does show that the temperature/timing information is not as clear as we would like to think. It is only his conclusion which is wrong:
He should have concluded something along the lines of; “The use of multiple proxies to assess the CO2/warming interaction is complete confounded by large variations in the data sets, with the result that no clear picture of the relationship can be seen. Further investigation of such relationships should perhaps concentrate on ice core proxies where the evidence for each parameter can be reasonably assumed to be physically locked into a reasonably close time bracket.”
agfosterjr says: April 6, 2012 at 11:56 am
I traced the trends at Maua Loa, 90N, 90S. The trend is highest 90N and lowest 90S. Eyeball and ruler. It is about 1.67ppm/yr 90S, 1.87ppm/yr 0, 1.93ppm/yr 90N for 1994-2004 .
On my screen, 10ppm is 2″. N&S were easy, 2004 was on a down slope so it was hard to pin-point 0. It shouldn’t be off by much more than a 1/16″, maybe an 1/8, not significantly different from the equator.
This suggests that CO2 may increase faster in the northern hemisphere.
With regards to the paper, it’s meaningless.
W., can you show the proxy temps and CO2 with a 500yr moving average, same start and end points?
RE
Willis Eschenbach says:
April 6, 2012 at 5:45 pm
“…The proxies are so varied, you can get any answer you want just by picking the proxies you want.”
Willis Eschenbach says:
April 6, 2012 at 11:03 am
“… they are averaging 80 proxies for historical temperature, but they’ve taken a single proxy for CO2.”
——————————–
Good stuff Willis. Your analysis and conclusions are clear and irrefutable.
rgb’s point above re the preponderance of coastal sites in the proxy data is also pertinent…
Now, my memory isn’t great but an infamous study using cherry-picked tree ring data springs to mind… seems to me the similarities are more than fleeting…
From Webster’s online dictionary:
Noun 1. propagandist – a person who disseminates messages calculated to assist some cause or some government
…”the cause”, “the cause”…!
Arno Arrak says:
April 6, 2012 at 6:32 pm
==============
Languages don’t always translate, common courtesy fells many more foes than belligerence.
Must be why the U.S. spends 800 billion on defense every year.
Arno Arrak says:
April 6, 2012 at 6:32 pm
Arno, I must confess I didn’t even read your comment. Why? The exact reason Anthony pointed out, the lack of paragraphs. I was actually tempted to comment on it, then I read his comment and just laughed.
Lots of folks seem to think that they can throw anything out in any form, and if the ideas are good and valid, that I and others will read them. Nothing could be further from the truth. You also need to speak the language that your listeners understand, in the manner they want it spoken.
I have a lot of folks who follow my work. In part that’s because I have good, new, interesting ideas, and I’m doing novel scientific investigations and analyses. This analysis is a good example of that. But that’s only part of it. People read what I write because it is two things—interesting and digestible.
By digestible, I mean that I cut it up into bite-sized chunks. I discuss the ideas one at a time. Not because people are too stupid to understand a whole big block of text—they are not, and it would be a grave mistake to think so.
But because it’s more fun to read that way. You need to attract readers, not encourage them to look elsewhere.
You have to understand that you are offering your ideas in a very crowded marketplace of ideas. There’s already over a hundred comments on this post, and it went up this morning. You see, I simply don’t have time to respond to, or even read, every comment in detail. I read a bit of each comment, I size it up, and I may just jump over it.
Yes, it’s true that some people’s comments I read no matter how they are laid out or formatted. Robert Brown, the Duke physicist who posts as rgbatduke, is one of those. His science-fu is strong, I read and carefully contemplate his words no matter how he writes.
But for someone who I don’t know, I give it a shot, and then I do my usual triage—no answer, short answer, or long answer. A giant long block of text with no breaks, almost every time that won’t get an answer.
Yes, I know it’s not fair. Yes, I know your ideas should get discussed based on their truth and their validity, and not based on how you expressed them … but this is 2011, and nobody has time to faff around decoding dense blocks of text. So if you want your ideas to get read and get discussed, I agree entirely with Anthony. You need to break them up into paragraphs.
Finally, neither I nor Anthony are saying this to score points. He’s trying to assist you in getting your voice heard and listened to, as am I, and you are tossing it back in his face.
Your choice, but I would suggest a gentler approach …
w.
aaron says:
April 6, 2012 at 6:57 pm
Yes, I can. So can you, for that matter, the data’s listed at the top. However, there are some difficulties. The main one is, what do you get when you average a lemon, a peach, and a watermelon?
Whatever ‘something’ these proxies are measuring, it’s clear that they are not measuring the same something. For example, the GRIP greenland ice cores show warming, starting 27,000 years ago. They warm slowly for about 10,000 years, then they warm rapidly to a peak about 10,000 years ago, and after that, they gradually cool down.
Now look at say proxy 32. Starting 27,000 years ago, it cools for 5,000 years. Then it starts to warm slowly … and it continues that slow warming for the next 20,000 years, finally peaking in about the year 1500.
So how would you average those two? And more to the point, what would it mean? You’re averaging a lemon and a watermelon, it’s meaningless.
w,
Willis’ point above re: presentation style is certainly valid. Nevertheless, I did read Arno Arrak’s mighty tome – and found it to be well-written and very interesting.
I wonder if Arno would consider re-writing as a guest post with graphs, figures, paragraphs and references/ links to break-up the text?
Adrian says:
April 6, 2012 at 5:51 pm
I love how when you agree with me everything is fine, but when you disagree I’m “showing my bias” …
No, that’s not the question at all. That would be a good question, but my question is, is the Shakun2012 paper a valid scientific paper or not?
I say no, based on the fact that they can’t draw their conclusions based on their proxies.
In addition, your accusation of “cherry picking” is risible. I can only analyze what the authors analyzed, and they analyzed the most recent glacial-interglacial cycle. All I need to do is show how and why their analysis of that cycle is fatally flawed, and I have done that. I am under no obligation to show anything about the other cycles.
w.
PS—When someone asks me “why did you only analyze one cycle?”, I answer them.
On the other hand, when someone accuses me of “bias” and of “cherry picking” for only using one cycle, I avoid that person in future, and I downgrade my opinion of their science and their impartiality.
You’re losing points fast … ask next time, your assumptions make you look both biased and unprepared …
Very interesting – given the issues that Willis raises and some of the interesting discussion in the thread, it really bothers me (yeah, I’m super naive) that the BBC World Radio Service has been running hot with the warmist claims being made by the study reviewed here. In Australia, the Fairfax media (The (Melbourne) Age, Sydney Morning Herald, etc) have also gone gang busters on this paper, claiming it seriously checkmates sceptic claims. Sigh. You guys must feel like you’re butting your heads against a wall at times. The Empire keeps striking back over & over with more bullsh*t, including rejigging the recent temperature record to show a continued warming trend. What will it take to put an end to them? Please PDO, weak Solar Cycles, etc, kick in harder. Until then, keep up the scrutiny, Willis & all the other sensible persons.
Oh & why isn’t WUWT selling Willis Eschenbach T-Shirts? Some of us like to wear our culture heroes, not just read them.
Willis – “Mosh is a friend of mine in real life, but his posting habits drive me spare … ”
I’m glad to hear that; was thinking of the recent dinner together, it would have been extremely awkward otherwise!
The key core truths for intrpreting these sort of data sets are
1. Southern Hemisphere changes more slowly that Northern because there si more water. Southern Hemisphereis better place to measure trends.
2. Greenland is the smallest large land mass in Northern Hemisphere. It will have the most variation of the major land masses in Northern Hemisphere which will have more variation than Southern Hemisphere So not surpising to see record delta Ts in both directions in Greenland.. Greenland is the thermal equivalent of getting AC electric power at the end of a long transmission line. The transients are bigger.
I went looking for the Shakun 2012 paper, Google Scholar didn’t even have the listing yet.
But it did find this:
http://www.sciencemag.org/content/318/5849/435.short
Download pdf here.
Deep-sea warming, which could cause outgassing of CO₂, preceded both atmospheric CO₂ and tropical temperature increases by ~1000 yrs, “in the Southern Hemisphere”. Isn’t the historical trend from ice cores etc that temperatures warmed for about 800 yrs, then came the atmospheric CO₂ increases?
Has this paper been mentioned before around here? I looked at the little captions on Willis’ little graphs, didn’t notice it by name. Was this paper or its data used in Shakun 2012?
I’ve posted the following charts, along with a discussion, as an update to the head post:
Blue line is the CO2 rise used in their paper.
w.
Jurgen says:
April 6, 2012 at 3:51 pm
“Your statement in my opinion only holds, if the measurements are about the same phenomenon and done with the same or comparable methods and units.
This is true for absolute measurements, quite so. But Willis derivatized all of the measurements (normalized) to sort out when change in any and all measurements occurred. In this case, my simple non-parametric method provides suggestive or supportive information.
Let me give a baseball analogy. A home run is hit at 3:02 PM at Yankee Stadium (is there another stadium?) We know a home run was hit during the game, just not when!
A video monitor registers the event with a time stamp at 3:02 PM.
At the same time, a scientist has a decibel monitor (he works for a government agency, like EPA, and wants to find evidence to require all ball park attendees to wear government-issued ear protection). At 3:02 PM he registers a spike in noise.
Another scientist is assessing neck strain in sports attendees (he works for NIOSH, and wants to mandate that employees only work so many hours because of looking-around neck strain). At 3:02 PM, he registers an increase in cervical neck rotation on his motion sensors, clockwise from spectators in the right stands, and counter-clockwise rotation from those in the left stands.
And so on—this analogy could go on.
But the conclusive video is lost!!!
Absent the videography, if one wanted to deduce when the home run was hit, and the data were appropriately normalized to fit to find time (Y-Axis), not X-Axis parameter, then putting the sonograph, the motion sensing graph, and other imaginary data too lengthy here to include, until we have 80 independent measurements, we can build a strong case that a home run was hit at 3:02 PM.
It doesn’t matter, in this instance and in Willis’ (really, really cool!) proxy splicing exercise, what exactly happened, just that something feasibly did happen, which was when the home run was hit.
Ergo: Based upon the mean of all data, estimated by totally different proxies, I hypothesize that the recovery from the interglacial maximized at around 6000±3000 YBP. That means that temperatures have been steady, or decreasing ever since.
The ice core data represent the ice that didn’t melt during a “deglaciation”. Think about it.
Arno Arrak says:
April 6, 2012 at 6:32 pm
Sorry, I agree with Anthony. I doubt many people are reading your comments, it’s hard to figure out the sentence structure.
Do you want people to read your comments? Then you need to write text that pulls them in and reinforces that attraction with every new thought. I didn’t read your one paragraph tome – a big, solid text post that cries out to be split into multiple paragraphs.
His blog, his standard. If you don’t like it, feel free to make one of your own.
-Ric
Al Fin says:
April 6, 2012 at 9:43 am
Nice punchline, Willis. Too bad members of the orthodoxy are not allowed to think for themselves. They might save themselves some embarrassment.
You have to have a conscience before you can be embarrassed…
michael hart says:
April 6, 2012 at 10:29 pm
OK, I thought about it … now what?
w.
And only six ice-core proxies. I wonder how many unique combinations of proxies Shakun et. al. tried, which ones were discarded etc. before settling on the 80.
Does any one know approximately how many proxies are actually available for use covering this (deglaciation) event?
Is it not obvious Willis has taken all the temperature records and not shown them as a global temperature? Even if at different times in different areas of the planet temperatures did not match up, you simply take an average over all..
A good example of what proxies can indicate, and what they can’t;, they are proxies after all, and they don’t all respond the same way, otherwise they wouldn’t be ‘proxies’ would they, they would be what are called measurements.
Too much of this sort of averaging between apples and oranges going on in the literature, to make proxies say whatever you want them to say.
“Take the blue pill, and you can believe whatever you want to believe”. Too many academics have taken the blue pill, I suspect.
Willis, here is a Greenland core
“Precise timing and characterization of abrupt climate change 8200 years ago from air trapped in polar ice”
Kobashi et al.,
http://icebubbles.ucsd.edu/Publications/Kobashi_8k_QSR.pdf
They have measured the entrapped Argon. As it is an inert gas, the levels of Ar should only respond to the oceanic temperature altering the aq/air partition coefficient.
The 8,200 event is also found contemporaneously in the South Atlantic; lovely pollen and carbon/sulfur records
South Atlantic island record reveals a South Atlantic response to the 8.2 kyr event
Ljung e al.,
http://www.clim-past.net/4/35/2008/cp-4-35-2008.pdf
This event would be the best bet to establish the true data of each level in a core.
Hey “UK”, remember, over here In the US, we speak softly but carry a BIG stick. 🙂
“You’re averaging a lemon and a watermelon, it’s meaningless.”
Did you know that an orange is a cross between a mandarin, and a pumello? It isn’t actually an original, naturally occuring fruit in the wild, which I’ve always found curious.
On another note, I learnt an interesting principle in chemistry 1 years ago, about combining, or averaging different things, to make a product. In chemistry, a compound of two different elements doesn’t necassarily have properties in any way similar to, or an ‘average’ of, its constituent elements. So water’s (H20) properties are totally unlike 2 single hydrogen atoms and one oxygen atom. Same goes for e.g. salt-NaCl-which as a compound has properties nothing like its constituent atoms, Na, and Cl, one of which is highly toxic-Cl.
Simply making the point that combining different things together doesnt necassarily mean you get something which is anywhere near an ‘average’, of the two. You can get a different beast altogether.
Poor proxy siteing, watermelons, cantaloup, squash, and radishes averaged, lack of thought and/or understanding of the individual data sets, what could go wrong with a recipe like that?
More bogus science pops out during another run-up to “Critical World Climate Meeting.”
More and more I think of Willis as THE FIREMAN, ’cause he sure puts out the CAGW fires. No, he’s not perfect, but when he makes a mistake, he admits it and goes on. But the vast majority of the time, he’s dead on, and thinking those marvelously clear, unconventional thougts about our world’s climate data, and I’m learning – admittedly five rows back from the front – from a Master of Science Fu.
Keep it up Willis, I’ve got so much more to learn. Thank you again.
————–
Kadaka (KD Knoebel) asks: What about the Stott2007 paper “Southern Hemisphere and deep sea temperature rise led deglacial CO2 rise and temperature warming”?
————–
Kada, that Shakun2012 article *DOES* discuss the Stott2007 article, and it discusses also a similar article by Hubers et al “Antarctic temperature at orbital timescales controlled by local summer duration” (2008).
In essence Shakun2012 argue — very reasonably IMHO — that because northern hemisphere temperature proxies substantially lead *ALL* southern hemisphere temperature proxies (including in particular the Stott 2007 and Hubers2008 proxies), the dominant climate-change drives are to be found in the northern hemisphere.
Willis, this point would be strikingly evident in your own analysis … if only you would color-code your data by latitude (per Shakun2012 Figure 5, for example).
Just to mention, it looks peculiar when WUWT criticizes an article for poor plotting practices … and yet WUWT the chooses to plot the data by methods that obscure the data’s most striking feature … namely, the north-to-south time-ordering of temperature rise.
For the above reasons, it has become plain that the WUWT/Eisenbach analysis *DOES* broadly verify with the Shakun2012 analysis. So just plot the data the best and clearest way, Willis … you’ll feel better for it, and WUWT will be better for it.
It would at least seem to be relatively easy to determine if temps precede CO2 changes. Take your paper-thin slice of ice from the ice-core just before the end of the glacial period, say 15 – 20 kyrs ago & analyze. Keep taking thin slices forward in time. When does the dO18 (temp proxy) begin rising? When does CO2 begin rising? I understand there’s a resolution issue — the thinnest slice may represent several hundred yrs, more or less. I’d assume that’s already been done & it was determined that dO18 started changing before the CO2 & that’s where the original conclusion that temps preceded CO2 came from. Is Shakun saying they got it backwards?
PS. Yes, I understand that temp drops at the end of interglacials occurred quite clearly before CO2 drops (by 1000-2000 yrs). I’m talking about the interglacial beginnings, which seem less clear.
Willis,
I can’t find any CO2 time series data in their S2 supplemental file “nature10915-s2.xls”. Can you point me to the source URI for the CO2 data?
RobRoy says: April 6, 2012 at 8:49 am
“It is my layman’s understanding that seawater, as it warms, releases CO2 dissolved therein. As seawater warms its ability to keep CO2 in solution decreases. This leaching of CO2 as the oceans warm is a great explanation for the correlation between temperature and atmospheric CO2 concentration. It explains why CO2 lags warming. Warming first then atmospheric CO2 increase. This is provable in a laboratory..”.
____________
First of all Rob, you are possibly on the right track – see Henry’s Law (1803) and the bit about temperature.
http://en.wikipedia.org/wiki/Henry's_law
Next, Shakun et al is nonsense. The paper is a veritable cornucopia of apples and oranges, grapes and bananas – and let’s not forget the watermelons.
It is interesting how often the global warming alarmists choose to ignore the Uniformitarian Principle AND Occam’s Razor.
CO2 lags temperature at all measured time scales from ~~600-800 years in the ice core records on a long temperature-time cycle, to 9 months on a much shorter time scale.
http://icecap.us/images/uploads/CO2vsTMacRae.pdf
We really don’t know how much of the recent increase in atmospheric CO2 is natural and how much is manmade – possibilities range from entirely natural (~~600-800 years ago was the Medieval Warm Period) to entirely manmade (the “material balance argument). I lean towards mostly natural, but I’m not certain.
Although this questions is scientifically crucial, it is not that critical to the current “social debate” about alleged catastrophic manmade global warming (CAGW), since it is obvious to sensible people that IF CO2 truly drives temperature, it is an insignificant driver (climate sensitivity to CO2 is very low; “feedbacks” are negative) and minor increased warmth and increased atmospheric CO2 are both beneficial to humanity AND the environment.
In summary, the “climate skeptics” are trouncing the warming alarmists in the “mainstream CAGW debate”.
Back to the crucial scientific question – is the current increase in atmospheric CO2 largely natural or manmade?
Please see this 15fps AIRS data animation of global CO2 at
http://svs.gsfc.nasa.gov/vis/a000000/a003500/a003562/carbonDioxideSequence2002_2008_at15fps.mp4
It is difficult to see the impact of humanity in this impressive display of nature’s power.
All I can see is the bountiful impact of Spring, dominated by the Northern Hemisphere with its larger land mass, and some possible ocean sources and sinks.
I’m pretty sure all the data is there to figure this out, and I suspect some already have – perhaps Jan Veizer and colleagues.
Best wishes to all for the Easter Weekend.
So Willis, are you going to write this up as a comment and submit to Nature? You should.
rgb
P.S. — thanks for the kind words about reading my posts, and I assure you that it is mutual and then some. I just wish I had more time to do some of what you are doing…
P.P.S. — what we really need is to get a clue as to why the current ice age — the one that started 2.5 million years ago — started. Without understanding this, trying to understand the physics underlying the current 110 ky bistability is pointless, as we do not understand the baseline of EITHER branch. I’m very tempted to try to write a simple cubic nonlinear differential model to try to model the base behavior, and then add various kinds of periodic noise to see if it can provide a clue concerning the quasiperiodic oscillations.
One very interesting thing revealed by this data is that (at least as far as this mostly coastal data is concerned) the Holocene peak occurred almost immediately after the warming that ended the Younger Dryas (that is now more visible in the B&W data, thanks, although I suspect that the downturn is dominated by the antarctic data from the colored plot — still something very interesting to look at here, separating out the datasets into ones that have a YD downturn and ones that apparently do not!). It would be extremely interesting to compare this temperature curve to Ushokin:
http://solarphysics.livingreviews.org/Articles/lrsp-2008-3/fulltext.html
(section 4.1, esp. figure 17). This figure more or less directly contradicts Lief’s litany that there was nothing unusual about the 20th century solar maximum. However, the really interesting thing about the temperature itself is that it has been gradually reducing since the peak — what’s up with that? The timescale of the decrease is millennial, a very slow, very gradual degradation. What kind of process in the Earth’s energy balance could be responsible for this? Are there critical points in the decrease?
What is missing, of course, is any evidence whatsoever that there is a third, still warmer, stable phase accessible in the Earth’s climate system. Its stable warm phase 5 million years ago was perhaps a degree warmer than the present. If we could stabilize the climate out of the ice age about this warm phase attractor, it would be totally amazing. Otherwise our ass is hanging out over a deep freeze that something could trigger, where we have no good idea of what that something is.
rgb
Thanks Willis, I learned a lot. Very interesting commentary too, thanks, almost everyone.
Ed Scott says:
April 6, 2012 at 8:26 am
April5, 2012
Climategate Heads to Court
By S. Fred Singer
http://www.americanthinker.com/2012/04/climategate_heads_to_court.html
Thank for posting this link; it is a good article.
From Skepticus on April 7, 2012 at 7:02 am:
Do you have a copy of Shakun2012 or was that mentioned elsewhere?
Stott 2007 and Hubers 2008 were too inconvenient to include, eh?
The Northern Hemisphere is weighted more to land area (low heat capacity) vs ocean area (greater heat capacity) than the Southern Hemisphere, it has greater fluctuations. The Southern has more ocean area and Antarctica, which “anchors” the climate.
Look to the large movements up North, figure that the movement is first there and then later down South so the South can be ignored as it doesn’t lead, seems as sensible as paying attention to the dog’s tail as the indicator of how the dog will move. The tail moves first and most, the body follows, therefore it’s obvious the tail indicates what’s controlling the dog so just pay attention to the tail only. Makes sense to you?
Skepticus says:
April 7, 2012 at 7:02 am
In essence Shakun2012 argue — very reasonably IMHO — that because northern hemisphere temperature proxies substantially lead *ALL* southern hemisphere temperature proxies (including in particular the Stott 2007 and Hubers2008 proxies), the dominant climate-change drives are to be found in the northern hemisphere.
No, the NH proxies do NOT “substantially lead *ALL*” SH proxies. Here’s the reality:
Going from north to south, the northernmost proxies (60N to 90N) are generally warming after the CO2 dataset that they use. Unfortunately, the pattern breaks down there. From 30S to 60N, there is no significant difference in the timing.
Then 60S to 30S is a bit earlier … and then to spoil the picture entirely, 90S-60S is later than 60S-30S …
No, it’s not “strikingly evident”, it’s not even true. There is no smooth transition from north to south as you claim. The majority of the planet (60N to 30S) shows no N/S gradient at all.
There is no significant “north-to-south time-ordering”. The furthest north data is somewhat different from the 60S-30S data … but the order reverses from there southwards.
Is that significant? Given the huge scatter in the data, it is very difficult ascribe statistical significance … but you’ll jump in feet-first nonetheless. They can’t find statistical significance using the proper 2-sigma error bars, so instead they show 1-sigma errors, ignoring autocorrelation … bad scientists, no cookies. If they showed 2-sigma errors including autocorrelation, you’d laugh. Or perhaps not, maybe you don’t understand significance and autocorrelation. They clearly don’t, here’s their Figure 5a
Note that when the error bars overlap, the result is NOT STATISTICALLY SIGNIFICANT, aka meaningless. Note that the error bars overlap on eight of the fourteen latitude bands. Note that they are using 1-sigma error bars. Note that if we take the proper 2-sigma error bars (twice as long), they all overlap, every one of them, and thus they are all meaningless. And that doesn’t even include autocorrelation, which will make things worse …
First, even their own data doesn’t “broadly verify” their own conclusions. They can only show the weakest, 1-sigma significance. If they used the proper 2-sigma error bars, they would have no significant results at all. They can’t even “broadly verify” their own claims.
Second, you say I’ll “feel better for it”? You are a nasty little man, sir, to accuse me of underhanded dealings in such a roundabout way. I am an honest man doing my best to present actual facts. Go wash your mouth out with soap, you’ll feel better for it, and WUWT will be better for it. Then go take a class in statistics, your knowledge is woefully deficient.
w.
Hugo M says:
April 7, 2012 at 7:50 am
I couldn’t find one either, so I digitized it from their graph …
w.
Great work all around, including Shakun who has provided the data and “forced” us to think in terms of synthesizing all this disparate proxy data.
Using the Antarctic CO2 is reasonable as CO2 is a well mixed (why does my inner voice keep singing “well dressed”?) non-condensing greenhouse gas.
I like aaron’s instinct to focus on the meridional trend. We need lots more data points.
In the end we are left where we started, knowing that CO2 and temperature are hitched, yet unsure which is the cart and which the horse.
But we may stumble with the locomotive metaphor. Uphill the horse pulls the cart, downhill the cart pushes the horse. We may even have a situation where carts can grow legs and horses wheels.
I did the mean and standard deviation of all of the studies, this time for the minimumtemperature observed. For all 80 studies those values are:
Mean ± sd = 23579 YrBP ± 15946
The median minimum temp. was 20367
Eliminating 2 sigma outliers (there were 3 of the 80) gives:
21023 ± 5908 YrBP (median: 20300) for the coldest interglacial time recorded by these proxies.
The outliers are interesting. They give very high values (one is 100,000+ YrBP, far away from the others). When you look into the data for the three, these are operating at the ends of their analytical standard curves, where error is large, or else where they do not have a standard, and are off the curve and have extrapolated into the beyond.
This assumes that these scientists are even using a linear standard curve. However, many of these researchers have to use what we used to call “fancy curves”. Like Log/Logit or some non-linear fit. These only operate within small regions of the curve, and only if a standard is nearby the point. Hence the error over large distances on the curve.
Anyway, 20,000 BC…When the land bridge would have been extensive, and animals could migrate. I would have waited a few thousand years until it warmed up a tad before I made the crossing.
Very cool work (no pun), Willis! Thanks for all of your mind-expanding efforts!
1) The timing of CO2 rising/falling is taken from the antarctic ice core records so they agree that it is a true record of global CO2 levels.
2) The first event in Shakun’s sequence is the tilting of the Earth, moving the North Pole into greater sunlight. Note that this also means that Antarctica gets less sunlight and also that northern oceans get more and southern oceans get less. The Arctic warms and fresh melt water runs off into northern oceans. Whatever happens next, warming started the process not CO2.
3) The northern oceans cool because the desalination stops the ocean circulations that bring heat from the equator to the northern oceans. However when the earth tilts, the line around the earth which gets the most heat from the sun is no longer the equator, the line moves north INTO the northern oceans. So why should the Northern oceans cool?
4) The heat at the equator backs up causing the southern oceans to warm. But the southern oceans are now getting less sunlight plus the heat is in the northern oceans so why should the southern oceans warm?
5) The southern oceans warm and cause an outgassing of CO2 which is accurately recorded in the antarctic ice core samples.
6) Shakun accepts that the ice core samples are a correct record of the antarctic and these records show that the Antarctic had been warming for 800 years before levels of CO2 but the first event was the earth tilting? What warmed antarctica then?
The whole thing just does not stack up.
Skepticus says:
“In essence Shakun2012 argue — very reasonably IMHO — that because northern hemisphere temperature proxies substantially lead *ALL* southern hemisphere temperature proxies (including in particular the Stott 2007 and Hubers2008 proxies), the dominant climate-change drives are to be found in the northern hemisphere.
Willis, this point would be strikingly evident in your own analysis … if only you would color-code your data by latitude (per Shakun2012 Figure 5, for example). ”
Skepticus, I was thinking the same thing. The fact that the different proxies have different time dependencies is nothing surprising. CO2 is a well mixed gas, but temperature change in the modern era is known not to be uniform, so why should we expect it to be so in the distant past? In addition, it is known that the tropical temperatures have about 1/2 of the variation of polar temperatures. The fact that a wide variation of temperature dependence is found among proxies scattered all over the earth is not proof that the proxies are wrong.
Of course, if one has a very strong belief that the Shakun paper is wrong, in order to avoid cognitive dissonance, one will accept any argument that is given, even if it doesn’t make sense.
I haven’t read the full paper, and am not familiar with the validation procedure used to calibrate the proxies, nor am I familiar with dating accuracy of the proxies. It seems to me that an argument about the validity of the proxies would begin with these items.
Eric Adler admits:
“I haven’t read the full paper, and am not familiar with the validation procedure used to calibrate the proxies, nor am I familiar with dating accuracy of the proxies. It seems to me…”
Obviously, Adler is ready to believe the conclusions of a paper that he hasn’t read, and admittedly doesn’t understand. However, preceding his frank admission, Adler says of anyone questioning Shakun’s flawed paper:
“Of course, if one has a very strong belief that the Shakun paper is wrong, in order to avoid cognitive dissonance, one will accept any argument that is given, even if it doesn’t make sense.”
Adler is hopelessly afflicted with psychological projection: imputing his faults, such as his own cognitive dissonance onto others. Appealing to the questionable authority of Shakun’s obviously grant-trolling paper would get a free pass by anti-science blogs like RealClimate or Skeptical Pseudo-Science. But not here.
Dung:
The southern oceans would warm and the northern cool bedause the thermohaline circulation is a wind and salinity tuned heat engine that pulls Arctic Ocean bottom water from the north Atlantic and distributes it to the Pacific and Indian oceans. Anything that puts a brake on the equalizing engine amplifies the disparity.
Gymnosperm
Shakun says that because the thermohaline circulation is stopped, heat builds up at the equator but that is incorrect. The hot zone moves north when the earth tilts and so the back up would be in the northern oceans.
I apologise twice, once for not understanding how you properly reply to forum posts, and second for you thinking that my sarcasm was an attack. I will format my reply using email standards – probably because I am incompetent?
>Willis Eschenbach says:
>April 6, 2012 at 7:47 pm
>>Adrian says:
>>April 6, 2012 at 5:51 pm
>> I’m normally a fan of your posts,but you are showing your bias with your commentry on only
>>the maxminums and trends.
>I love how when you agree with me everything is fine, but when you disagree I’m “showing my bias” …
I didnt disagree with your analysis, I just said it was misdirected. I said more than that, but hopefully you understand that not describing the minimums shows a bias. I dont actually know what the minimums show – i havent downloded the data -, but they are more germaine to the result.
>> The question is w[h]ether CO2 rises proceed temperature rises, so the minimum comment[.
>In addition, your accusation of “cherry picking” is risible. I can only analyze what the authors
analyzed, and they analyzed the most recent glacial-interglacial cycle.
Ok so transer my criticism to them.
> All I need to do is show how and why their analysis of that cycle is fatally flawed, and I have done that. I am under no obligation to show anything about the other cycles.
You might not be under obligation, but if you are “prepared” – joke see later — you can do the analysis.
w.
> PS—When someone asks me “why did you only analyze one cycle?”, I answer them.
> On the other hand, when someone accuses me of “bias” and of “cherry picking” for only using one cycle, I avoid that person in future, and I downgrade my opinion of their science and their impartiality.
>You’re losing points fast … ask next time, your assumptions make you look both biased and unprepared …
Point scoring is stupid, truth is binary, lol
I already said I didnt read the paper — and wont for other reasons…
W., sorry for pestering. I have pain problems and haven’t done an analysis. I’m on the computer too much as it is.
An analysis in a ling time.
RE
Allan MacRae says:
@ April 7, 2012 at 8:27 am
Very well put Allan. Clear, concise and hits the nail right on the head.
Willis Eschenbach you have been giving all the proxy records used in the paper from 80 different sites around the planet, you clearly plot them as a group (http://wattsupwiththat.files.wordpress.com/2012/04/standardized-temperature-data-shakun2012-proxies-26000.jpg), yet you don’t average them all out??
CO2 is a greenhouse gas.. and this is all based on “global” temperatures.. The study is not an in depth tale of local proxy records and what they mean, its a global study and should be treat as such. You clearly say
“I fear that this set of proxies is perfectly useless for that. How on earth could you claim anything about the timing of the warming from this group of proxies? It’s all over the map.”
Its obvious they would all be different, that is the point, its a global record.. Stand up and average them out, even your simple standardized method will most likely show the warming trailed CO2.
Dung says:
April 7, 2012 at 1:13 pm
2) The first event in Shakun’s sequence is the tilting of the Earth, moving the North Pole into greater sunlight. Note that this also means that Antarctica gets less sunlight and also that northern oceans get more and southern oceans get less. The Arctic warms and fresh melt water runs off into northern oceans.
and at point 3:
However when the earth tilts, the line around the earth which gets the most heat from the sun is no longer the equator, the line moves north INTO the northern oceans.
Dung says:
April 7, 2012 at 2:12 pm
The hot zone moves north when the earth tilts and so the back up would be in the northern oceans.
Dung, are you sure the change in tilt Shakun et al. refer to has these consequences? I think not. I cannot find the exact data about the changes or “wobbles” in the Earth’s orientation but as I understand the basic dynamics, it’s about an increase of the tilt, resulting in bigger seasonal differences both north and south . So also the Antarctic gets more sun in it’s summertime.
So for the amount of sunlight on the sphere of the Earth there is this basic symmetry between north and south independent of the tilt. The asymmetry is in the spreading of the landmasses, there is more of them in the northern hemisphere. This makes the difference when the tilt changes.
Several of the commenters have repeated the “CO2 is well mixed mantra”. This is wrong based on the satellite images previously posted on this site. CO2 isn’t well mixed, and that might just lead one to question whether Antarctic CO2 is a global measure. Granted, with only two areas on the planet with ice cores extending that far back, it’s the only game in town, but the dice are rigged, even if we don’t know how much.
Nonetheless Willis’ analysis isn’t dependent on that, it is an analysis which shows that conclusions drawn by the papers authors are faulty, OK, false. They can’t say what they’ve said, the data doesn’t back them up.
The commenters yelling for an ensemble average of the proxies are just showing how poorly science is taught today in some institutions. It saddens me to have to include my alma mater (ETHZ) in that group.
Robert Brown says:
April 7, 2012 at 8:43 am
I have not had the greatest of luck with that in the past, although I was successful with Nature in a “Communications Arising”. The format is tough, 500 words from memory. That’s a squeeze, although I suspect that the graphics alone would be enough to tip the scale.
I am very fortunate that I am an amateur scientist.
The key to understanding the climate is that the climate is a natural heat engine that is constantly adapting and evolving to maximize its performance.
In terms of the climate as a whole there is a dual maximization. What is maximized is the sum of the work done and the energy moved.
The work done is the motion of the working fluids against the natural fluid braking system. In the case of the climate, the fluids are the atmosphere and the ocean. In other words, the work done is turned to heat in turbulence of the atmosphere and the ocean against the land and the seabed. Maximization of this aspect is the maximization of entropy.
The energy moved, on the other hand, is the energy that is transported from the hot end of the heat engine, the tropics, to the cool end of the heat engine, the poles.
Obviously, the two parts of this dual maximization work against each other. Turbulence is the enemy of transport.
As a result, nature always ends up running a little ways into the onset of turbulence.
Now, all of this is going on subject to the physical constraints. These include the shape of the seabed, the location of the continents, the height and location of the mountains, and the like.
What does this have to do with ice ages? One possibility for the onset of the ice ages was the closing of the Panama Seaway 2.5-3 million years ago. When that happened, it interrupted a huge flow of water from the Atlantic to the Pacific. My guess is that the El Nino-La Nina phenomenon didn’t exist when the Seaway was open, but I’ve never found a way to verify that. In any case, there’s more info here.
Now, recall that the climate is a huge heat engine constantly adapting to maximize turbulence plus energy moved. With the closure of the Seaway, it shifted its oceanic and atmospheric circulation patterns to a new, bi-stable state.
Mmmm … not sure that will do it. The problem is, most of the models have been written by physicists who understand radiation, when they need to be written by engineers who understand both Carnot and the Constructal Law.
I cannot emphasize the latter, the Constructal Law, strongly enough. It is one of the few fundamental laws discovered in my lifetime. The discoverer, Adrian Bejan, is number 40 on the list of the most-cited scientists on the planet … and yet many scientists are unaware of his work and its implications for a host of scientific fields, including the climate.
Best to all, new post on Shakun coming up, always more for me to learn,
w.
aaron says:
April 7, 2012 at 4:13 pm
My friend, chronic pain is one of the most wearing and unbalancing forces I know of. Take care of yourself, focus your intention on getting better, don’t let my words concern you.
My best wishes for freedom from your pain,
w.
After reading the paper, it is so clear how you have shown the proxy records as a whole and negated the fact the Northern Hemisphere warmed completely differently to the Southern. i39.tinypic.com/f0qkcw.jpg
Of cause you are going to get some proxy’s start warming at different times..
Jurgen says:
April 7, 2012 at 6:09 pm
for the amount of sunlight on the sphere of the Earth there is this basic symmetry between north and south independent of the tilt.
Just talking tilt here. As the Earth’s orbit is not just circular but elliptic there is also the effect that around the perihelion the sunlight is more intense. In Anthony’s post referring to the Shakun paper it says: “Small changes in the Earth’s orbit around the sun affected the amount of sunlight striking the northern hemisphere, melting ice sheets that covered Canada and Europe.” I take this for the perihelion effect coinciding with summer in the northern hemisphere. But then later on Clark is cited talking about “Earth’s slow wobble” – and I take it this refers to the tilt. So it is about a combination of both effects.
WordPress is playing tricks with me. The above link is redirected to another post both in Firefox and Google Chrome. So to be sure, this is the link:
http://wattsupwiththat.com/2012/04/04/a-new-paper-in-nature-suggests-co2-leads-temperature-but-has-some-serious-problems/
My comment at
major9985 says:
April 8, 2012 at 3:42 am
the link should have been:
http://i44.tinypic.com/34gncox.jpg
Question to Willis.
Having skimmed through the article about the constructal law:
https://public.me.com/ix/williseschenbach/Constructal_Climate.pdf
and not being well acquainted both with thermodynamics and the physics of atmospheric and oceanic circulation patterns, and reading in their summary:
“New flow systems coexist with old systems, but persist in time if they are better, while older systems gradually disappear. This never-ending parade of flow systems represents the generation of flow architecture – the generation of geometric form as the clash between objective and constraints in flow systems. This is the phenomenon summarized in the constructal law.”
… I am inclined to rephrase this into: “the constructal law explains the generation of flow architecture as an evolutionary optimizing phenomenon in terms of thermodynamics and fluid dynamics”.
Is this rephrasing legit? If so, it is tempting to generalize this law to the biosphere, talking about evolution. Guess I’m getting over-excited now.
Trying to get some layman’s hold on the principles involved here.
re: “I think I can see the face of Jesus in the Fig 9 plot! /sarc”
Sorry, I couldn’t leave that one alone. It’s not Jesus, but I found a good correlation:.
[IMG]http://i42.tinypic.com/rwqkp2.gif[/IMG]
Perhaps this will work better:
http://tinypic.com/r/rwqkp2/5
Jurgen says:
April 8, 2012 at 7:20 am
The Constructal Law has huge implications for biology. See, for example, Bejan’s latest book, Design in Nature: How the Constructal Law Governs Evolution in Biology, Physics, Technology, and Social Organization.
There’s more good stuff at the Constructal Theory Web Portal. And no, you are not “over-excited”. The implications of Bejan’s work are immense and largely not appreciated.
w.
Andrew says: April 7, 2012 at 5:08 pm
RE Allan MacRae says: @ April 7, 2012 at 8:27 am
Very well put Allan. Clear, concise and hits the nail right on the head.
_______
Thank you for your kind words Andrew.
For those who are interested, this video of Murry Salby on atmospheric CO2 is 32 minutes of presentation, plus questions.
Sydney Institute: Salby Aug 3, 2011
Or if the above link does not work, watch the Salby video here
http://youtu.be/YrI03ts–9I
Willis Eschenbach says:
April 8, 2012 at 10:19 am
– – – – – –
Thanks for the reply Willis and the extra info. To be honest with you I am awe struck by the image on the book cover. The tree-structure is a long-time fascination of me, but you don’t see it often pictured in this way as it should be: a bridging structure between two media. This structure is reflecting a basic dynamic you see everywhere in all kind of variations. My entry into this phenomenon was way back finishing my study in town-planning as I was concentrating on decision making processes. I couldn’t impress my professor with my idea’s but it never left me. Happy to see it now alive and kicking.
Typo “Now, there’s plenty of things of interest in there.”
And you end up with something completely meaningless.
Jurgen
thank you for correcting my unfit for purpose knowledge of the earths axis 🙂
Jeff Alberts says:
April 8, 2012 at 5:54 pm
“major9985 says:
April 7, 2012 at 4:37 am
” Is it not obvious Willis has taken all the temperature records and not shown them as a global temperature? Even if at different times in different areas of the planet temperatures did not match up, you simply take an average over all.. ”
And you end up with something completely meaningless.”
There have been a gazillion papers written by Climate Scientists on the average global temperature. They certainly believe the average global temperature is an important and meaningful quantity, even if you do not. It is your opinion that is meaningless.
I’m confused about this post.
Shakun et al claim that the proxies differ: that the single antarctic proxy previously used is not representative of the global picture. You plotted the proxies all on one plot, and they end up all over the place, which is perfectly consistent with their claim.
What’s the issue?
Of course, Shakun et al then take this complete mess and summarize it intelligibly by doing an area-weighted average. That gives us a global temperature map to look at, from which more interesting conclusions can be drawn — for example, about the timing of the temperature increase.
Just because they want it to have meaning doesn’t mean it does. Look up “intensive variables”.
Shakun et al claim that the proxies differ: that the single antarctic proxy previously used is not representative of the global picture. You plotted the proxies all on one plot, and they end up all over the place, which is perfectly consistent with their claim.
The reason they can make the assertion that they do is that the SH warming (apparently) precedes the NH warming by a statistically resolvable time lag. As the South Pacific warmed and the Pacific in general followed — being the world’s largest ocean, covering roughly half of the Earth — the CO_2 level went up. It had to go up, because there is a huge amount of CO_2 dissolved in sea water and raising the temperature alters the equilibrium concentration, although we don’t really know what the temperature of the bulk of the ocean was at that time. When Willis plotted the temperatures by latitudinal band in the “Tricksie” post, a potential problem with both the original paper and Willis’ method is revealed (that I just noticed).
Obviously the warming observed at any given site is completely different. This is apparent in the non-renormalized data. However, the conclusion of Shakun is highly dependent on the SH warming first. The way Willis plotted it in Tricksie, it does — the polar region in particular appears to lead the CO_2 by 1000 years or more. The two localized proxies from the intermediate southern latitudes appear to perfectly bracket the CO_2, and indeed all of the equatorial data from both the NH and SH do as well. It is the NH data from the upper latitudes and the poles that appears to lag the CO_2 (although it then must dominate Shakun’s estimate of mean global temperature.
However, there is an implicit assumption built into this that is not really justifiable. The ranges of these curves are not really comparable — in particular the anomaly presented on the left is not a meaningful quantity. How, and in particular when, can one normalize it? If one shifts it up it makes warming precede CO_2. If one shifts it down, it works the other way. Since one has no absolute number from which it begins or to which it goes at the end, and since the tropical anomaly is not close to the polar anomaly in size, one is comparing apples to oranges to grapes to bananas, and ignoring all of the inland guavas and kumquats and kiwis and pears and…
This makes everything arguable — in both directions. Looking at the NH polar data in Tricksie, it looks like the NH polar temperatures bumped some first, before either CO_2 or southern polar temperatures. But then it they stubbornly refused to bump and actually went down until there was a sudden surge right before the YD, even as CO_2 was steadily increasing. Shift this curve down a bit and it looks like CO_2 leads NH polar temperatures (and since there is no absolute scale, who knows what “zero” really is)? Shift it up a bit, and CO_2 leads the temperature.
Willis, one thing you might want to do is plot not the curves themselves, but their slopes or even their second derivatives against CO_2 concentration. What one is looking for is force, or acceleration of temperature trends, inflection points where something changes. The “lag” in the climate behaves something like a “mass” in physics — changing the driving may not even change the slope of the temperature curve any more than pressing on the brake instantly makes your car move in reverse, but the causal effect of a brake is a negative acceleration that is instantly observable.
To put it yet another way, it isn’t the absolute magnitude of the temperature that matters — that is determined by past history in a complicated non-Markovian differential form. It isn’t the slope of the temperature that matters — that too appears to have an “inertia” that causes it to lag or lead driving forces by as much as 1000 years (for understandable reasons, e.g. thermalization times of the oceans). It is the rate that the slope changes — when one changes the “forcing” of the system, one really should fairly rapidly see the slope itself start to change in close correspondence with the important drivers.
This works both ways — it applies to the CO_2 curve as well.
In the data for 60N to 90N, the slope of the temperature goes from flat to increasing around 21 kya, when the CO_2 curve is flat (especially flat if one includes the rest of the CO_2 data omitted by Shakun) and boring. Around 17 kya it actually goes flat to negative — there was a significant thermal deceleration around 19 kya and it remains flat with no forcing correlation with the CO_2 right up to 14 kya. It then spikes up — in response to some enormous “force”, peaks, and then falls almost as rapidly with no possible way to interpret CO_2 as the active agency responsible for either one. Only then, around 12 kya, around the end of the Younger Dryas, does a strong positive slope emerge that appears almost perfectly correlated with the CO_2. However, the way it is plotted one can argue that the CO_2 is dragging up the temperature. It is only when one looks at the inflection points, not the non-normalizable curves themselves, that it is clear that this is not what is happening.
rgb
major9985 says:
April 7, 2012 at 4:37 am
Major, you and Jeff Alberts seem to think that any average is meaningful … here’s a couple examples showing why that’s not true.
You can go out and measure people’s income. If you measure the income of every man and woman in America, you get a meaningful number for the income of the average American.
But that doesn’t mean all averages are meaningful. You and Jeff seem to be the kind of guys who would do the measurements and come back to proudly announce that you have researched the question extensively, and that the average American has exactly one breast and one testicle … sure, you can take the average of anything, but the answer may not mean anything …
w.
rgbatduke says:
April 9, 2012 at 8:38 am
Take a look at the graph I presented of the different latitude zones, here, I’ll show it again:
As you point out, the issue is when the inflection point occurs, the turning upwards of temperature or CO2.
Starting from the South Pole, the region 60-90S starts to increase at the same time as CO2.
The next region, from 30-60S, turns upwards slightly before the CO2, so their hypothesis is already in trouble. It should turn later than the region further south.
The next three regions? I’d say they are too diffuse to even begin to say when they turned. However, all three appear to have turned at roughly the time the CO2 did, with one perhaps turning a bit before and another a bit after the CO2.
Then we have the northern data. It turns upwards slightly later than the others.
Net result? Well, if we take the southernmost region as our starting point, three of the other five regions don’t show us anything. Of the remaining two, one is going the right direction and one is going in the wrong direction …
As a result, I’d have to say that their “south to north” hypothesis, while not falsified, is certainly not supported by the data that they have presented. And the difficulties don’t stop there. Look at e.g. proxy 42, and see if you can tell me the timing of the transition …
w.
numerobis says:
April 8, 2012 at 9:33 pm
Area-weighting is completely inappropriate for this dataset, it is far too sparse. All it has done in their case is to hide the effect of the one completely unusual area represented by the two Greenland proxies.
w.
Do you have any explanation for why it’s invalid to do area-weighted averaging here? It certainly seems like a better approach than the prior approach, which was to take a single ice core as being globally representative.
I’m also failing to understand the analogy between area-weighted averaging of temperature proxies and summing exotic fruits. These aren’t smoothies we’re making, it’s converting various proxies into temperature anomalies and averaging those to get a global record of prehistorical temperatures. Proxies have generally bigger errors than historical instrumental records, and we’d prefer to have more of them than just 80, but that just means you have bigger error bars.
Willis, please re-read my posts. I’m arguing the exact opposite. Some averages are meaningful. A global average temperature is not.
Jeff Alberts says:
April 9, 2012 at 6:31 pm
Indeed, my apologies for the misunderstanding.
w.
numerobis says:
April 9, 2012 at 12:20 pm
Indeed I do, and it’s the subject of my new post here.
Thanks,
w.
“Indeed, my apologies for the misunderstanding.”
😉
Then we have the northern data. It turns upwards slightly later than the others.
Are we looking at the same figure? The northern data turns up well before the inflection point in CO_2, then goes down as CO_2 initially rises before turning around to catch back up. In fact, the northern exhibits a relatively weak warming trend some 3000 years before anything else, at a time the southern pole is if anything cooling and CO_2 is basically flat.
I agree that the major upward inflection appears to be delayed, but the data still leave that initial warming to be explained, as it occurred very early and was if anything correlated with flat to dropping CO_2. If anything, this suggests that the entire CO_2 rise was directly associated with warming oceans. Warming at the inland greenland sites was obviously not well-correlated with oceanic warming, and there isn’t a lot of northern polar open ocean, and what there is was very likely at a very uniform -4 to 4K temperature. In the south and central latitudes, however, when the warming started it was associated with warming the ocean, releasing trapped CO_2. This may well have provided some positive feedback to the warming, but it wasn’t a very strong one or the cold phase ice age wouldn’t be stable to the many southern warming events that happen across the 90,000 years out of every 100,000 that fail to trigger a reversion to warm phase globally.
Until one fully understands why the cold phase is cold and what destabilizes it so that warm fluctuations can grow (where before they did not) work like Shakun’s cannot reliably support any CO_2 linked hypothesis, only the observation that yeah, warming oceans release CO_2 so that the two things go hand in hand globally. Positive feedback should have predicted a continued rise in temperatures following CO_2 across the YD. Instead we have the opposite — a levelling of CO_2 in response to levelled or dropping temperatures.
rgb
Willis:
Thankyou for yet another of your superb critiques of a paper.
I write to support two comments you have made in the subsequent thread.
At April 6, 2012 at 6:01 pm you say;
“What I’m seeing from these proxies is that we don’t know as much as I thought we did about the shape and timing of the emergence from the last ice age. The other proxies tell a very different story from the ice cores …”
And at April 6, 2012 at 7:28 pm you say;
“Whatever ‘something’ these proxies are measuring, it’s clear that they are not measuring the same something. For example, the GRIP greenland ice cores show warming, starting 27,000 years ago. They warm slowly for about 10,000 years, then they warm rapidly to a peak about 10,000 years ago, and after that, they gradually cool down.”
Yes! Oh, yes!
I have repeatedly pointed out (in several places including WUWT) that
(1) ice core data are useful because they indicate CO2 concentration and isotope-derived temperature data from the same trapped gas bubbles
but
(2) ice core data are NOT a direct indication of anything because
(2a) different ice cores provide different indications
and
(2b) other proxies (e.g. stomata data) provide different indications to those of the ice cores and to each other.
The entire AGW edifice is built on dubious data. Therefore, much that is asserted as being “known” (e.g. temperatures and their changes, atmospheric CO2 concentrations and their changes, etc.) is very, very debateable. Please note that this applies to both proxy-derived data of the distant past and to measurement-derived data averaged to provide global and hemispheric information of the recent past.
With the possible exception of the satellite-derived data, all of the basic climate parameters are of unknown accuracy, reliability and precision. And this problem becomes obvious whenever different data sets for the same parameter are compared.
Richard
Hi Willis,
your work looks impressive, but as a non-expert I am wondering how you produced your graphs. One of the things about the hoaxers in the climate debate is the lack of transparency. So the more transparency you can provide the more credible your case will be. Can I ask you to explain what tools you have used to produce these graphs ? I presume you loaded the data from the excel sheet provided by Shakun into a tool and then ran some scripts. It would be great if you could document these steps and publish them. This is all the more important asthere are already allegations out there about manipulation. It would also allow your supporters to redo the plots and confirm or correct what you are saying.
These comments are made in the spirit of open, honest science, reading what people like you have to say without prejudice.
Wishing you all the best
Kevin Mannerings
Kevin Mannerings says:
April 17, 2012 at 1:29 am
Thanks, Kevin. I do my work in a combination of Excel and the computer language “R”. R is free and it’s wicked powerful. One of the best things about R is that at any time you can run one line or part of a larger program. This gives great freedom, and leads to execrable code, at least when I’m writing it.
I’ve zipped the CSV data files, along with the R file, and put them online here (127 kb zip file).
However, I must warn you that my code is very poorly commented, and in no particular order, because I just pick the lines that I want to run and run them.
All the best,
w.
Hi Willis,
Don’t worry about the comments in your scripts. As a tester I am used to that :-), I would like to have a look at it, as it might be useful for the tests I am doing on Piers Corbyn’s eathquake forecasts. Unfortunately, the link you gave is not working. You can mail me on kevinDOTmanneringsATgooglemailDOTcom.
Rgds, Kevin
Kevin Mannerings says:
April 17, 2012 at 11:07 pm (Edit)
Sorry, Kevin, bad link. I fixed it now, give it another try.
All the best,
w.