WUWT readers, Figure 4 is noteworthy, because it points out the trend of 20th century warming in context with other periods of warming derived from the ice core record. I suggest you bookmark this post and that graph, as it tells a simple but indisputable story. – Anthony
Guest post by Frank Lansner
In a recent article:
http://wattsupwiththat.com/2010/09/08/working-925-what-a-way-to-make-a-livin-at-agw/
I estimated the total raw CO2 warming to be around 9,25 times the warming effect of one CO2-doubling:
Fig 1
Heat from one CO2-doubling (the “CO2-sensitivity”) has been estimated by IPCC and J. Hansen to be 3K or even 6K, including feedbacks. The 9,25 CO2 “doublings” cannot all have such a huge effect including feedbacks, so present day conditions on Earth must be extraordinarily heat sensitive (at least according to the IPCC).
Claim: Just a tiny temperature increase under present day conditions (like raw effect of one single CO2 doubling) should result in temperature jumps of up to 3 – 6 K.
Is this claim supported by evidence?
Fig 2
I have examined high quality Vostok temperature ice core data from the interglacial periods of the last half million years. These warm periods are the best evidence we have from Earth to examine the dynamics of present day climate on Earth.
We are looking for other huge temperature rises of 3K – 6 K that should result from just minor temperature rises.
Below I have identified all temperature rises of the Vostok data fulfilling the following criterion: “Temperature at the beginning of temperature rise must be at most 1 K below today’s temperatures indicated by -1K anomaly in the Vostok data. Next, the examined periods must be at most 300 years in length (we want to focus on the warming effect of one century time intervals) and finally, the initial temperature increase from glacial to interglacial is not included”:
Fig 3
96% of all temperature increases are between approx 0 and 1,4 K, only in one situation (approx 1 %) we find an interglacial temperature increase of almost 3 K.
That is: Under present day like conditions, temperature rises of 3K are very rare indeed, while smaller temperature rises of around 1 K are abundant and normal.
The interglacial periods shows no temperature peaks of the size interval larger than 3K. If in theory a minor warming of 0,5 – 1 K should lead to a 4-5-6 K warming including feedbacks, why are there no such peaks in the previous interglacial periods? There are plenty of 1K warming peaks (resulting of from all kinds of natural mechanisms) to induce the massive positive feedbacks that IPCC and Hansen expects.
Fig 4
The average interglacial temperature rise (from these data criteria) shows a warming of 0,65 K and lasts 113 years. In average they begin at –0,17K and end at +0,48K. (These averages are only to some degree dependent of my definition of interglacial periods – unless my definition of interglacial periods are totally wrong.)
The average temperature increase for these data of 0,65 K over 113 years – does not exactly make the modern temperature increase 1900 – 2010 of around 0,6-0,7K appear that special, does it?
Fig 5
The data tell us more: When the time intervals exceed around 100 years, the average magnitude of the recorded temperature increase does not increase. This is interesting and surprising because a longer interval should give time for a larger temperature increase. But on average the time intervals in data longer than around 100 years shows smaller net temperature rises indicating – unless this is a coincidence – that temperature peaks of the interglacial periods in average lasts around roughly 100 years.
Via Joanne Nova, I got a feedback to this result from George White:
“The analysis is consistent with long term averages changing more slowly than short term averages. The correlation drop at 100 years is because of a periodic effect of about 180 years. After 90-100 years, the direction of the temperature change reverses and the deltaT drops. If the analysis is continued, a second peak should appear between 250 and 300 years as a result of the second cycle of this period showing up with a minimum centered between the peaks. ”
Interesting, and thanks to George White.
When nature has warmed the planet over 100 years, this warming seems to END rather systematically. If positive feedbacks were strong why do temperature rises end so systematically? At least this warming-turn-off suggest that:
Natural forces or perhaps negative feedbacks are stronger than positive feedbacks after just a limited warming over 100 years
In addition, we see very few small temperature increases (of the order of 0 – 0,15K) for time intervals less than 150 years. On the other hand, the longer time intervals shows several of these tiny temperature increases. This indicates – unless it’s a coincidence – that if at first, temperature is on the rise, it often continues to rise until a significant temperature rise is reached. In other words: Temperature variability is the norm and constant temperature seems unusual.
Conclusion
Nature has provided us with data telling a simple story: For periods on earth comparable with today, we see many examples of temperature increases in the magnitude of 1 K for all kinds of natural reasons. Very rarely does any temperature rise (via supposed positive feedbacks) reach 3 K within 100 years.
It is thus surprising that IPCC and others with big confidence can claim large temperature rises of up to 3 – 6 K as most likely result from just a minor temperature increase, for example induced by CO2 warming.
More, it appears (fig 4.) that the temperature rise of 0,7K from 1900 to 2010 is as normal as can be when comparing with other temperature rises during other warm periods.
***
Comments
1) I have defined “interglacial temperature rises beginning at -1K compared to modern temperatures, no lower. On this definition I found that the temperature increase 1900-2010 was normal. If I had defined interglacial periods as starting at -2K, then there would have been a few more temperature increases in the area 1-2K which would make the present temperature rise appear smaller in comparison. However, the limit -1K for interglacial periods mostly is in compliance with the nature of the interglacial periods. When first we have interglacial period its not often we find temperature in the area under – 1K. Therefore I found -1K to be the best choice to limit interglacial tendencies. Also, temperatures should resemble today’s temperature range as close as possible.
2) I have used 0,7K for the temperature increase 1900-2010. This is obviously highly questionable due to significant UHI measuring problems and adjustment issue that is likely to have exaggerated the temperature increase 1900-2010. On the other hand, temperature variations at Vostok are likely to be larger than global temperature changes, so perhaps a qualitative compare is somewhat fair after all. At least, if you claim that the present temperature increase is extraordinarily large, I think one should show data that supports it. And, as I showed, Vostok data does not really support the claim.
3) By Joanne Nova: “In the past natural temperature rises we should also see the positive feedbacks at work. But it is very difficult to isolate the exact amount of warming due to the natural forces vs that due to the natural feedbacks. Where does one stop and the other start? In any 3 degree rise, how much was due to the forcing, and how much to the feedback? If positive feedback was strong we would expect to see examples of it occurring in the past ice cores.”
Frank: This is very true and makes this topic a little fluffy to deal with. However, the absence of 3K – 6K temperature rises in the interglacial periods means that there should not have been any natural warming excl feedbacks of just 0,5 K or so (matching the raw CO2-sensitivity warming). And we still can see that the temperature rise 1900 – 2010 is just a normal interglacial variation.
4) Hereafter it could be interesting to do analysis using Dome C core temperature data that has twice a many data points for temperatures which may refine the results to some degree.
Source used for Vostok data:
http://www.ncdc.noaa.gov/paleo/icecore/antarctica/vostok/vostok_data.html
See also:
http://joannenova.com.au/2010/08/ice-core-evidence-no-endorsement-of-carbons-major-effect/
http://hidethedecline.eu/pages/posts/925—a-factor-that-could-close-the-global-warming-debate-193.php
http://wattsupwiththat.com/2009/01/30/co2-temperatures-and-ice-ages/
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
It’s a very, very clever incubator.
Frank Lansner says:
Here is where your logic is wrong:
(1) You are exaggerating the role claimed for positive feedbacks. The “bare” response to the radiative change due to doubling CO2 is about 1.1 C. The prediction is that feedbacks multiply this number by a factor of about 2 to 4 (thus giving us a range of about 2 to 4.5 C). This is hardly turning something “little” into something “huge”. Rather it is making something reasonably big even bigger.
(2) Given that, you simply haven’t demonstrated that the lack of large heat spikes is due to a lack of feedbacks. It could simply be due to the fact that forcings have been fairly small (especially once you say that “the initial temperature increase from glacial to interglacial is not included”). [You also seem to be ignoring larger temperature changes that are seen over short time periods that are thought to be more local than global changes…but I guess one could at least justify that.]
So, your conclusion that the sort of rises predicted by the climate models are unprecedented (at least looking back over a short enough period of time and ignoring the larger events I mention) does not imply that they can’t occur. They are unprecedented for exactly the reason that worries scientists: namely, that the perturbation that we are imposing on the climate system by raising CO2 far above levels seen for at least 600,000 years, and probably several million years, is an unprecedented perturbation, at least in recent times.
Furthermore, by looking further back in time and by not ignoring the glacial-interglacial transitions, one can actually estimate the forcings and get empirical estimates of the temperature change that occurred and can use this to estimate the climate sensitivity. And, as I noted in a previous post, most of the estimates come out in the range of sensitivities that the climate models suggest, if not higher.
Rocky Road says:
No you haven’t. You have just misunderstood what you have read. The point is that all because chickens produce eggs does not imply that eggs can’t also produce chickens. The close correlation of CO2 and temperatures over a variety of timescales is suggestive of the correlation going both ways. While the change in temperatures seems to start first in the glacial – interglacial case because those transitions are understood to be initiated by changes in the earth’s orbit around the sun (and axis of rotation), the changes in greenhouse gases follow along soon enough that there is still plenty of room for the change in greenhouse gas levels to amplify the warming or cooling once it has begun.
The additional evidence for this notion that changes in CO2 are a cause as well as an effect of warming comes from a theoretical understanding of the radiative effects of CO2 as well as from quantitative estimates of the various forcings during the least-glacial-maximum relative to now: Those estimates show that about 1/2 of the forcing comes from changes in the earth’s albedo (due to the growth and decay of ice sheets and changes in vegetation) but that a little less than half comes from the changes in greenhouse gas levels. (I think Hansen estimates about 40% from all the greenhouse gases, or about 1/3 from CO2 alone.)
The reason that changes in greenhouse gases don’t often seem to INITIATE warming or cooling in the paleoclimate record reflects the fact that there are generally not large and fast spontaneous natural increases in these gases (although the PETM may have been a case where there was). We, however, have figured out a way to very rapidly (on geologic timescales) take greenhouse gases that nature locked away in stores over millions of years and release them back into the atmosphere. It is a likely an experiment with few past precedents, although there is still enough we can understand about past events to determine that the effect of doing this is likely to be significant.
Bill Illis says:
December 9, 2010 at 4:42 am
I have also done this over the entire paleoclimate record. I don’t think there is really a correlation at all of temperature versus CO2 (and it is certainly less than 3.0C per doubling). So, other factors are more important in driving the historical climate. Maybe CO2 contributes, but it can only be 20% to 30% of the variation.
http://img801.imageshack.us/img801/289/logwarmingpaleoclimate.png
Excellent presentation of an important point. It would be great to have the source data for this chart (the data points at least) – is this available?
Thanks to all who responded to my earlier post.
Frank Lansner says:
December 9, 2010 at 9:56 am
John, its widely accepted that CO2 itself will just create a minor temperature increase. The “dangerous” part is that IPCC et al. claims that just a little heat today will create huge positive feedback and thus huge temperature increase.
So, John, CO2 – natural or not – is only itself resulting in a tiny temperature increase.
Essentially then, since man’s contribution to atmospheric CO2 is so minor, it doesn’t have enough effect to make a “look back” at previous data not be germane.
To Ric Locke –
I’m just asking if the anthropogenic addition would have any effect which might alter what was put forward by Lansner. I do believe though, that there are many who accept that we humans are adding measurably to the atmospheric CO2 level. I do not agree with Warmists that this contribution makes any appreciable difference to atmospheric temperature, however.
Thanks also to Canadian Mike and JJB MKI for their responses.
I appreciate the efforts Anthony and the other contributors, including “repliers”, expend to make clear that which the Warmists deliberately endeavor to keep murky.
nofate says:
Indeed, the difference in global average temperatures between the last glacial maximum and now was about 5 or 6 C and, as you note, that difference was enough to make the ice atop Chicago a mile high. It was also enough to make the sea levels many tens of meters (or even a couple hundred meters?) lower. So, yes, global temperature changes of 2, or 3, or 4 C do seem quite alarming to me.
Interesting…You have presented a plot that combines together two disparate sources. And, one is a modeling of the CO2 levels (with huge errorbars as that figure indicates if you look closely). It is fascinating that people who call themselves “skeptics” seem to blindly believe any data from sources without any attempt to verify the data, find out what the errors are in the data, or what the time resolution is in the data. And, that is leaving aside the issue of the other forcings that operate on timescales of tens of millions of years, like continental drift.
The fact is that as the general trend has been that as the resolution and precision of the paleoclimate record of past CO2 and temperature levels improves, any apparent lack of correlation between the two seems to yield to quite good correlation (at least going back a few million years…beyond that the data isn’t generally good enough yet, except for dramatic events like the PETM and the issue of other significant forcings operating on longer timescales becomes more important).
This is why there is a gulf between what paleoclimate scientists have concluded and what some skeptics have concluded from throwing together a plot using temperature and CO2 data from different sources (one modeled) with large error bars and various problems with resolution, not to mention being over timescales where we know there were other larger forcings operating. This is the difference between using science to learn about the world and misusing it to just confirm what one’s ideology makes one want to believe is true.
steven mosher says:
December 9, 2010 at 10:52 am
trying to deduce the sensitivity from the paleo records is well known, and its considerably more complex than you present here. The first problem of course is that all your measures already include the feedbacks so they cannot be so simply distangled.
This is a classic tactic used by a scientific establishment to counter an inconvenient argument – drown it in irrelevant extraneous complexity and detail. I have seen it in action in other scientific fields such as epidemiology and radiation biology, and am very familiar with it.
The method used by Frank Lasner is scientifically solid (in science never confuse simplicity with weakness) – restrict the analysed period to the interglacial plateaus only, and analyse only the fluctuations in temperature, not involving CO2 or anything else. Just statistical analysis on temperature fluctuations / oscillations within interglacials. What he targets is not the whole of climate science, just a specific argument within CAGW that a small temperature increase per se, caused by CO2 (or presumably anything else) must set off positive feedbacks resulting in a large temperature excursion highly damaging to the ecosystem – i.e. that the climate and biosphere (in flat contradiction to the voluminous evidence of the palaeo record) are inherently unstable and that the existence of our own life and biosphere after 4 billion years of this precarious instability is in fact impossible and must be some artefact or illusion. Lansner’s well defined and limited argument destroys the possibility that global climate is unstable due to positive feedbacks and that small temperature changes are amplified to larger ones. This is falsified – instead temperature increases occur as expected from a log-log power law distribution in a quasi-chaotic / nonlinear system, and that temperature rises are self-limiting by negative feedbacks and have a well defined distribution of magnitudes and durations.
Just look at what happens. Just look frankly at the world THE WAY IT IS. Why does this approach give the scientific establishment such difficulty?
The paper you cite is a good example of bringing in irrelevant detail:
Petr Chylek (any relative of the Chelsea goalkeeper?)
Institute for defense of the status quo and cosy government sinecures, Zurich.
… A novel feature of our analysis is the use of a cooling period between about 42 KYBP (thousand years before present) and LGM to provide a constraint on the aerosol radiative forcing.
No – not novel at all. Just business as usual for government science minders to escort off the scene an inconvenient argument. Lansner specifically excluded the large temperature changes at the boundaries of interglacials, to characterise fluctuation within an interglacial. So to overwhelm this inconvenient argument with a cloud of unknowing, lets distract attention from this well defined and precise argument by bringing in a completely different argument involving bigger fluctuations from glacial to interglacial.
Nice try though.
Hi Joel.
You open up a long row of subjects, so lets start with someting simple:
In this article “Is the warming in the 20´ieth century extraordinary?” i show the warming 1900-2010 vs the heat spikes of the interglacials. I make clear that the present warming data includes UHI and warming adjustments, but on the other hand the Vostok data normally is expected to vary more than the global average. So its a qualitative compare but stil, these are the data we have and does not really suggest something quite extraordinary about the present heating.
Can you to some degree agree on this?
Next you calculate your way to expected CO2-sensitivity of 2-4,5 K. I do something else. I use the IPCC´s own “best estimate” of 3 K and then Hansen older “best estimate” estimate of 6K. I then search for peaks between IPCC best etimate and Hansens estimate. (IPCC gets their 3 K from an average of several different papers, including papers up to 5 K CO2 sensitivity).
The raw CO2 effect: As demonstrated, there are around 9,25 raw CO2 doublings to equal the total raw total CO2 contribution. Using 1,1K gives a total raw CO2 contribtion of over 10K, that is around a third of the total present greenhouse effect. But due to the greenhouse dominans of mostly water, the real fraction of raw CO2 effect is often reffered to as 15% or so, half you value. If true you should use 0,5-0,6K.
Or take the MODTRAN model, here you get around 2 – 3 W/m2 per doubling:
http://hidethedecline.eu/media/CO2sensi/fig1.jpg
And since its normally accepted that we have 4-5 W/m2 = 1 K, again we end up with 0,5 – 0,6 K for Co2 sensitivity.
Lindzen even suggests 0,5 K for CO2 sensitivity INCL. feedbacks?
As I remember, the latest IPCC report uses around 72% feedbacks vs 28% raw Co2 warming. This would give 0,76 K raw CO2-warming from their best estimate of 3K incl feedbacks.
BUT! lets just use 1 K for CO2 sensitivity as you mention.
Under these circumstances a warming of 1K should lead to 3K warming incl feedbacks (IPCC) or up to 6K (Hansen and others).
So if anything gave a direct warming of 1 K earlier in interglacials we should have seen a warming continue to 3 – 6K.
But this has hardly ever occured in interglacials at all.
There can be 2 reasons
1) IPCC and Hansen are wrong
or
2) There has never been a direct raw warming of 1 K in the many 10 thousands of interglacial years.
See temperatures. http://www.physics.rutgers.edu/ugrad/140/vostok_ice_core.jpg
And what did i then conclude?
“It is thus surprising that IPCC and others with big confidence can claim large temperature rises of up to 3 – 6 K as most likely result from just a minor temperature increase, for example induced by CO2 warming.”
Dont you find it surprising, that IPCC and others can claim to be “confident” of the strong feedbacks when we dont see many big warming peaks (3-6K) in the temperature data? Perhaps you think that these ice core data strongly supports this IPCC claim? If so, I would like to know how you argue for this.
K.R. Frank
Joel Shore and Steve Mosher,
So what Albedo value was used in all these climate model simulations of the paleoclimate which apparently included all the known forcings?
They are all “___” because the ice age simulations just made up the forcing numbers especially the solar forcing/Albedo part so they could come up with the result they wanted. The other time-period ones also fail because the climate models they used apparently skipped Grade 3 Math class – like where the teacher explained 2 X 3.0C = 6.0C is the right answer and 2 X 3.0C = 1.5C is the wrong answer. They all assume people won’t actually check their data and their math and apparently no climate scientist actually does and magically, it gets published.
This blog post represents a kind of straw man argument. The statement made in the hockey stick paper, is that the current temperature increase is a unique event in the past 1000, years, and didn’t include the interglacial periods for the past 400,000 years. The projection of global warming does not rely on the hockey stick paper, or any characterization of the current temperature change as being unusual. It relies on the physical understanding of the effect of CO2 on the climate, including feedback.
In fact a look at the Vostock ice core data, shows how the projected effect of CO2 increases can be associated with huge changes in temperature.
Looking at the Vostok graphs, one sees that a change in CO2 from 180 to 280ppM was correlated with an increase of temperature of 10C. The CO2 change was less than one doubling. This means it is possible for CO2 to have a huge temperature effect.
It is true that CO2 increase was not the only change driving temperature. The tilt of the earth’s axis and precession of the earths orbit triggered it, and different feedbacks including changes in albedo due to snow and ice as well as the CO2 changes were responsible for amplification of the intial orbital forcing. Some kind of simulation modeling which takes many factors into account is needed to determine the effect of CO2. This is what Hansen and other researchers have done to come up with the range of climate sensitivity that is quoted by climate scientists.
http://naturalscience.com/ns/articles/01-16/ns_jeh2.html
Of course the change in CO2 in the modern period is much faster than what happened during the ice ages, and CO2 is a primary driver of warming, rather than a feedback factor, as it was in the ice ages. The physics behind it is the same. Since the heat capacity of the oceans is large, and the change in net energy flux is small, the full surface temperature change that is associated with the change in CO2 from 280 to 390ppM has not yet occurred. Another 0.4 to 0.7 C increase is expected even if the CO2 concentration stays where it is.
eadler says:
“…the Vostock (sic) ice core data, shows how the projected effect of CO2 increases can be associated with huge changes in temperature.”
Your entire argument swirls down the drain due to the fact that rises in CO2 follow temperature rises.
Want some graphs showing that CO2 follows temperature? How many do you want? Ten? Twenty?
Just ask.
Sorry about your repeatedly falsified conjecture.
nofate says:
December 9, 2010 at 11:19 am
steven mosher says:
“If people dont accept the fundamental physics ( C02 warms) then they have no voice in the scientific debate and no standing in any moral debate”
That’s cute. So anyone who disagrees with you is immoral? No matter what their standing in the scientific community? So I guess Mr. Pachauri, by your reasoning, is a moral, upstanding world citizen? Haven’t you posted here before? How about the moral standing of Mr. Watts and all the scientists who visit here? So why do you bother with us?
###############
Anthony, willis, lindzen,monckton, christy, spencer all accept the basic science
and the radiative properties of C02. They argue that the effect of C02 while real is small. I will put it to you this way: if a person does not accept the fact that the moon is smaller than the sun, is there any sense in discussing a scientific controversy with them? is there any sense is discussing a moral dilemma with them? I’d say no. It’s largely a waste of time. Simply, skeptics can and do accept the fundamental science of the radiative properties of C02. Those skeptics, Like Lindzen, get a seat for the scientific debate. It is also the case that people are more likely to listen to them about the moral debate as well. But no one who rejects the fundamental science, gets heard in the real scientific debate and people wisely ignore them in the moral debate.
That’s just some advice, not a judgement.
“Seems to me, if you marginalize us at the start, there is no debate. Oh yeah, I forgot, the debate is settled. There is no science left to explore, there is only consensus…. Says you (and AlBore).”
Well, you dont read. There is a debate about the sensitivity. That’s an open complicated issue. If you want to be heard, then there is a ticket to that debate.
There is also a moral debate: what’s our obligation? If you want people to take you seriously in that debate my suggestion is that you accept that portion of AGW that
the skeptics like Lindzen accept. That’s practical advice.
KD in Milwaukee says:
December 9, 2010 at 11:03 am
Hoooray at last, thankyou KD.
I can’t vouch for Franks data or methodology, I don’t have that experise. But as KD says, it doesn’t matter if a period of warming was by the sun, CO2 or dino farts.
The man is looking for PRECEDENCE. And he is looking for it during a 500,000yr period. And his conclusion is that with the exception of a few outliers, at no stage during that time did Ts rise in an “unprecedented” way.
Discussions about sensitivity etc are totally irrelevant for the purposes of this paper.
So, from all the knowledgeable WUWT readers, what we are looking for is for example the following……
Now c’mon folks, Frank has put time and effort into this, lets help out, it may be a benefitial contributor to the climate debate.
And to the person who evoked the “get it published in peer review” all I can say is get a life you parrot. HERE IS THE PAPER FOR ALL THE WORLD TO SEE, it can be reviewed by not just 3 faceless nepotists, but by anybody who wishes to, OPENLY.
Have you got any constructive comments be they positive or negative? have you got the kahones to review it in full public scrutiny? Do it and gain respect.
p.s have yet to read comments past KDs
phlogiston says:
Franks method is solid? Well, I’m sorry he did does not establish a repeatable or testable method. There are methods that mathematicians have developed for diagnosing sensitivity from observations. Schwartz attempted this, I believe spenser has as well. Frank would need to establish that his method works. he could do this with synthetic data ( generate data from a known process, add noise, add dating error, add temperature estimation error and show that his mathematical method could reconstruct the sensitivity from the observations)
Here is a simple model that uses temperature observations
to estimate sensitivity ( after Scwhartz)
http://rankexploits.com/musings/2008/how-large-is-global-climate-sensitivity-to-doubled-co2-this-model-says-17-c/
Or if you want to join my friends Ryan O, JeffId, And Steve Mc and write a paper on diagnosing sensitivity from Vostok, start reading what has already been done. A small sampling.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VF0-48DYTM7-11&_user=10&_coverDate=05%2F31%2F1993&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1574162343&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b26a531bfa36ac1e9e22d49c88677d23&searchtype=a
Here is something simple on ice sheet forcings. and showing how well you can estimate paleo temps if you do it right.
You see one test of your method of extracting a sensistivity from observations is how well your method can predict.
http://www.google.com/url?sa=t&source=web&cd=4&ved=0CCoQFjAD&url=http%3A%2F%2Fwww.atmos.washington.edu%2F~dennis%2F321%2F321IntroLecturea.pdf&ei=WrABTbKACoTQsAO1w9yyAw&usg=AFQjCNHM_vPOaIWsS5C9LxbKu9W3pl7_rQ&sig2=pIQr6K1Kg93hAFulLcSE3w
Or you could read alley’s paper… or the studies he cites:
The data thus indicate that the globalization of the orbital ice-age signal was
achieved by CO2 . The climatic sensitivity to this forcing can then provide a test of
the sensitivity of climate models.
A simple way to do this was presented by Hoffert & Covey (1992), who compared
the global-mean temperature change and the change in forcing from greenhouse
gases, albedo, etc., to obtain a climate sensitivity to CO2 for both glacial-maximum
conditions and conditions from the warm mid-Cretaceous of ca. 100 million years
ago. Hoffert & Covey’s (1992) sensitivities to CO2 doubling were 2.0
± 0.5 ◦ C for
the comparison with ice-age conditions, and 2.5
± 1.2 ◦ C for the comparison with
mid-Cretaceous conditions, or an average sensitivity of ca. 2.3 ◦ C. Models used in
the IPCC (2001) produce estimates that range from 1.5 to 4.5 ◦ C for the warming
from a doubling of CO2 from recent values, so the initially reassuring result from
Hoffert & Covey (1992) was that palaeoclimatic sensitivities were slightly less than
the midpoint of those models.
However, it now appears that higher sensitivities are indicated by data from both
warm and cold climates. Starting with the cold climates, the Hoffert & Covey (1992)
ice-age estimate was based on early palaeoclimatic data that rather clearly under-
estimated changes (specifically, the CLIMAP sea-surface temperatures (SSTs)). As
updated by Cuffey & Brook (2000), improved data yield a sensitivity of ca. 3.9 ◦ C
warming for a CO2 doubling, which falls towards the upper end of the IPCC sensi-
tivities.
Or this to give you some idea of the other forcings you have to consider.
http://www.google.com/url?sa=t&source=web&cd=19&ved=0CFoQFjAIOAo&url=http%3A%2F%2Fwww.physics.rutgers.edu%2Fugrad%2F140%2FNature_399429a0.pdf&ei=cLMBTc6DBY_0tgPnuPzSAw&usg=AFQjCNFM-QWTaREiLQZfNfMn8-6iBy3HZA&sig2=IEKIh_79zYnQH1VDgN-wyA
Joel Shore says:
December 9, 2010 at 2:03 pm
Thanku Joel, that’s the type of analysis required, and put politely, thnx again.
Please answer my dillemma, you say…
Unless I misunderstand your meaning, you are saying feedbacks are/may be limited? i.e. once a forcing induces a feedback, that feedback is used up.
What are the limitations of feedbacks? Do we know at what level of T do those feedbacks cease?
If a forcing induces T rise of say 0.1DegC, feedbacks increase that to say 0.25DegC. Why can’t this 0.25DegC induce further warming to 0.375DegC?
Does a molecule of H2O on the suface skin of the ocean know the difference between 0.1DegC of warming by forcing and 0.1DegC of warming by feedback?
I can see limitations due to WV saturation, have those limitations been quantified?
regards
eadler says:
December 9, 2010 at 6:03 pm
The actual net effect of additional CO2 in the atmosphere is in reality an unknown at present. Any claims that all or most of the warming of the 20th century is due to CO2 are, at full face, inaccurate. Such claims neglect to account for any natural warming OR for other influences by man such as land use.
On the other hand, the warming is not unique to the Holocene. The warming, statistically, can be said to be expected. It occurred right on schedule. Though at present we cannot explain, in full, what causes the cycle of warming we can likewise, not accurately determine to what extent man has influenced warming until we can separate the natural from that anthropogenically induced. Such task is difficult due to a lack of full understanding of either. At this point theoretical SWAGs are what is being generated. Little more.
Fortunately there are those who realize the ‘debate’ is not over. They continue doing valid science in search of fact and truth. The ‘debate is over’ group (not a crowd) continue with self-serving rhetoric and little real science. Time and reality will continue to defeat them.
Eadler, you write: “This blog post represents a kind of straw man argument. The statement made in the hockey stick paper, is that the current temperature increase is a unique event in the past 1000, years, and didn’t include the interglacial periods for the past 400,000 years. ”
Eadler, besides the problems with the Hockey-stick claims themselves …
(summarized here: http://wattsupwiththat.com/2010/04/04/ipcc-how-not-to-compare-temperatures/
1) the Mann material, 2) the Briffa material, 3) The cherry picking done by IPCC to predominantly choose data supporting colder Medieval Warm Period, 4) Problems joining proxy data with temperature data mostly obtained from cities or airports etc, 5) Cutting proxy data of when it doesn’t fit temperatures from cities, 6) Creating and Using programs that induces global warming to the data and finally 7) reusing for example Mann and Briffa data endlessly (Moberg, Rutherford, Kaufmann, AR4 etcetcetc) and 8) Wrong compare. )
Then the problem is indeed if some “scientists” do not check out the past before claiming “confidently” what will happen in the future. In the periods I analysed, the temperature rises occur around half the time, and if they do not take into account how the Earth reacted for ten thousands of warm years in interglacial periods, then i do think thats a severe mistake. Obviously you need this info before you start shouting out how earth will and should react now under same conditions.
K.R. Frank
steven mosher says:
December 9, 2010 at 9:09 pm
phlogiston says:
Franks method is solid? Well, I’m sorry he did does not establish a repeatable or testable method. There are methods that mathematicians have developed for diagnosing sensitivity from observations.
Thanks for these useful references to studies of sensitivity in the palaeo-record. I will try to look them up over the weekend.
However Lansner’s article and argument were not about sensitivity. Thus my point about inappropriate conflation of his point with other topics. He is just making a simple point in a rather innovative way – starting a new debate, not jumping on board a well-established one i.e. sensitivity.
Lansner is (if I am right) just characterising the statistical nature of temperature fluctuations in the ice core record, and asking whether the trends and patterns visible in this fluctuation support the hypothesis that small increases in global temperature are inevitable amplified by positive feedback to become larger ones . This argument is implicit in the writings of the IPCC and James Hansen. It emerges instead that the 20th century warming is slap bang in the middle of the “normal” distribution of many hundreds of similar temperature rises during recent interglacials – an in being about 100 years long his approach even suggests (“predicts” would put it too strongly) that this increase is over and that temperature decrease is likely to follow.
The sort of temperature fluctuation he analyses is of a fractal nature, so in fact although he restricted it to the interglacials, the same analysis would hold true if extended to the whole Vostok and other ice core records. The fluctuations arising from a system exhibiting non-equilibrium nonlinear dynamics is described by a log-log relation – plot log of size of temperature changes with time against log of the frequency of changes of each magnitude, and you get a straight line. This means lots of small changes, fewer big changes, much fewer very big changes. It is a universal feature of such systems.
Understanding the nonlinear / nonequilibrium nature of the climate system fundamentally changes the role or feedbacks. It is absurd to characterise such a system as having positive feedback at a global level. Instead local and time-limited positive feedbacks operate, but they run their course and terminate (Bob Tisdale uses the term “saturate”). The ENSO is an example of this. The potential for local positive feedbacks to occur characterises the system as a reactive or excitable medium – the tension between positive and negative feedback results in emergent spatio-temporal pattern formation. These patterns are the climate – which cannot be analysed by simple linear global heat balance equations, because it is nowhere near equilibrium.
Steven Mosher, tanks for long and detailed input on Vostok Co2 sensitivity 🙂
But i think you are missing the points. (It reminds me of a study i made giving much more protein from yeast cells for insulin production. One professor was irritated that I had not used more mathematical analysis… but Novo Nordoc used my results for their world wide production…)
Question:
1) Do you see the temperature rise 1900-2010 in appear alarming when comparing with the other teperature rises?
(yes as i wrote in the article, UHI and adjustment likely to exxagerate modern warming while on the other hand the locality of Vostok exxagerates temperature rise to som degree compared to global data)
Do you think that ice core data thus can be used to claim with big “confidence” that present warming is quite extraordinar?
If not ice core data can be used, what data can be used?
2) You are talking a lot about “my method” 🙂
My “method” is simply to look at interglacial data where 3K temperature peaks appears rare.
And then I ask:
“How can IPCC etc. be so confident that today Earth will bring about a 3K temperature rise as result of a smaller CO2-warming?”
Perhaps you can answer then?
?
(Not to mention those who feel “confident” that earth will react even stronger today:
http://hidethedecline.eu/media/CO2sensi/fig5.jpg
Here you see an example of “scientists” very very confident that Earth will now react with temperature rise beteen 3K and 7K before year 2100. In this period we wont even have one CO2 doubling so their idea of the earths reaction to a minor Co2 warming to begin with is perhaps 5K – 10K (!) and thus they seem more hard core alarmists with his 6K claim.)
K.R. Frank
PS: its NOT because i dont want to discuss all other aspects you drag in(!) but lets first relate directly to the content of the article.
This is a very simple and elegant idea. I hope this can be developed and that in time it will appear in peer-reviewed scientific papers. If this idea is right – and I think it almost certainly is – then it is of the utmost importance, for it strikes at the very heart of that ruinous belief known as CAGW.
A couple of years ago I read a piece in New Scientist. It said in effect: okay, so the ice core data shows that the CO2 follows the temperature – but this means it’s a positive feedback, so we’re doomed after all. It probably never occurred to the writer that if there were a positive feedback at work then it would appear clearly in the data. As far as I’m aware the ice core data shows no sign of the temperature being driven by CO2. And this excellent piece by Frank Lansner takes it even further. Quite possibly the ice core data provides the biggest and most important disproof of CAGW – and maybe of AGW as well.
Chris
Hi Chris, and many others for the interest and kind words!
if interested here some other writings, pretty NASTY in their conlusions as well:
Dec 2008, WUWT, I show that it takes more and more heat to provoke the same rise in CO2 of the atmosphere. It tells us about future CO2 levels and the mechanisms keeping CO2 levels down:
http://wattsupwiththat.com/2008/12/17/the-co2-temperature-link/
Jan 2009, WUWT, I show that CO2 levels have little influence on temperature:
http://wattsupwiththat.com/2009/01/30/co2-temperatures-and-ice-ages/
April 2009, WUWT, I collect 59 peer rev datasources to evaluate historic and holocene temperatures.
I find date with fine Antarctic MWP in higest resolution, I find not so big difference between SH and NH when it somes to MWP and much more:
http://wattsupwiththat.com/2009/04/11/making-holocene-spaghetti-sauce-by-proxy/
FEB 2010, http://www.hidethedecline.eu , with the help from Nicolai Skjoldby i got a full sceptic climate A – Z online.
Examples/”Highlights”:
The Alps and the MWP: http://hidethedecline.eu/pages/posts/alps-the-98.php
Climategate oveview: http://hidethedecline.eu/pages/c.php
CORAL GATE, I digged in coral data….: http://hidethedecline.eu/pages/posts/corals-and-the-great-barrier-reef-43.php
Why has CO2 level in oceans stopped increasing a decade ago?? http://hidethedecline.eu/pages/posts/co2-carbon-dioxide-concentration-in-the-oceans-72.php
History of CO2 concentrations: http://hidethedecline.eu/pages/posts/co2-carbon-dioxide-concentration-history-of-71.php
Water gate… About positive feedbacks! http://hidethedecline.eu/pages/posts/feedback-positive-ndash-rdquowhat-makes-co2-heat-dangerousrdquo-29.php
The “Venus Argument”: http://hidethedecline.eu/pages/posts/rdquovenus-argumentrdquo-the-5.php
and so on and so on 🙂
FEB 2010: UHI – A World tour! http://hidethedecline.eu/pages/posts/urban-heat-island—world-tour-155.php
MAR 2010: Glaciers, Oerlermans data: http://hidethedecline.eu/pages/posts/the-warm-glacier-temperature-reconstruction-of-oerlemans-2005-160.php
Mar 2010, WUWT, After the apr 2009 article i discovered that result for the MWP to a significant degree changed after IPCC changed viewpoint:
http://wattsupwiththat.com/2010/03/10/when-the-ipcc-disappeared-the-medieval-warm-period/
Mar 2010, WUWT, I look into temperature graphs from the 1970´ies:
http://wattsupwiththat.com/2010/03/18/weather-balloon-data-backs-up-missing-decline-found-in-old-magazine/
Apr 2010, WUWT, I show severe error on the hockeystick used by IPCC
http://wattsupwiththat.com/2010/04/04/ipcc-how-not-to-compare-temperatures/
MAY 2010: PETM – Finally data that could rescue the CO2 theory? http://hidethedecline.eu/pages/posts/petm-ndash-finally-an-example-of-co2-causing-heat-179.php
Jul 2010, One of my best writings (!!!!!) I just haven had the time to promote it yet. After the Mar 2010 article about old temperature graphs i made a COMPLETE OVERVIEW of the pre-GW temperature material in easy to understand illustrated writing:
Here a Core illustration of how IPCC has kept important data from the viewers:
Check it out: http://hidethedecline.eu/media/PERPLEX/fig2.jpg
The article: http://hidethedecline.eu/pages/posts/the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-180.php
Aug 2010, WUWT, DMI summer data for 80-90N and other data tells a very different story than GISS data where land data is used over ocean:
http://wattsupwiththat.com/2010/08/05/dmi-polar-data-shows-cooler-arctic-temperature-since-1958/
http://hidethedecline.eu/pages/posts/colder-arctic-temperatures-in-the-melt-season-vs.-giss-temperatures-188.php
sep 2010, WUWT, I show from MODTAN model, that there are around 9,25 co2 “doublings” in total Co2 effect. All has same raw effect, and if the next doubling causes great warming it must have a different effect than the rest of the CO2, more positive feedback:
http://wattsupwiththat.com/2010/09/08/working-925-what-a-way-to-make-a-livin-at-agw/
oct 2010, i defend my Aug article, and in this context i would like to focus on this Chryosphere correction so it wont be forgotten:
http://hidethedecline.eu/media/GlobalIceExtend/fig4.jpg
And finally, Dec 2010, http://wattsupwiththat.com/2010/12/09/is-the-warming-in-the-20th-century-extraordinary
Before 2008 dec i only wrote for dansih sites.
K.R.Frank
Woops my Joanne nova Writings:
http://joannenova.com.au/tag/lansner-frank/
K.R. Frank
Like Jo Nova points out:
“The interglacial periods shows no temperature peaks of the size interval larger than 3K. If in theory a minor warming of 0,5 – 1 K should lead to a 4-5-6 K warming including feedbacks, why are there no such peaks in the previous interglacial periods? There are plenty of 1K warming peaks (resulting of from all kinds of natural mechanisms) to induce the massive positive feedbacks that IPCC and Hansen expects.”
Assuming the forcings were enough for 0.5 K warming, then the 1 K warmings you observe are consistent with a ~2 K climate sensitivity. The values are consistent with us not getting a forcing of greater than ~1.5 W m^-2 (for 3 K sensitivity) or ~2 W m^-2 (for 2 K sensitivity)
The natural warming of the 20th century is not extraordinary, as the geological record conclusively shows. Changes of several degrees throughout the Holocene have happened repeatedly. In fact, current temperatures are quite normal and benign. Nothing unusual is happening.
The MWP was warmer than today and the LIA was colder than today. Only climate alarmists like Michael Mann claim that the climate didn’t vary much until the industrial revolution began [the long, straight handle of his fabricated hockey stick chart]. But Mann et al. have been debunked by McIntyre and McKittrick among others, and he is being increasingly marginalized by reputable scientists.
Someone who only has a hammer will see every problem/solution as a nail that needs pounding. Having met Steve Mosher I can tell you that he is a very nice guy, and knowledgeable, too. I bought his book, and highly recommend it.
But Steven is a computer model guy. And climate models have an abysmal prediction record. They are all over the map, as Lucia’s chart shows. And of course Hansen’s models could be replicated as accurately by a chimp with a dart board.
Models have their uses, and they are being constantly improved. But they still can’t predict temperatures a mere two years out, even using 2-sigma error bands. Real world observations are the natural starting point for any scientific conjecture, and real world, unadjusted observations show conclusively that nothing unusual is occurring regarding global temperatures. It has all happened many times before.
A ±3°C variation in global temperature is completely natural and routine, and has happened throughout the Holocene. Yet the UN’s proposed world regulations would require drastic, very expensive [to U.S. taxpayers] action if the global temperature exceeds a mild 2°. That is not science; that is planning on a statistically likely event in order to extracy hundreds of billions of dollars from U.S. taxpayers based on a likely occurrence. The UN is not stupid. But they are very devious and mendacious.
Finally, the question of climate sensitivity is regularly discussed here. The response of the planet itself indicates a low sensitivity to CO2. The wildly high claimed sensitivities of 2.5°C and above are not supported by empirical observations, but by models programmed by people with a vested interest in showing a high sensitivity number.
I would personally give great weight to Professor Richard Lindzen of M.I.T., who puts the sensitivity number at not much over 1°C – a very modest rise for a doubling of CO2, which is itself an unlikely event from this point in time.
We employ true experts in the field such as Dr Lindzen because their many decades of studying the climate is something most of us don’t have the time for. In life and in education, experience counts for more than almost anything else.
Because Lindzen puts his reputation on the line by citing a specific sensitivity number, rational people will rightly give that number great weight. It is certainly much more credible than the self-serving, unelected, and relatively inexperienced pronouncements of the UN/IPCC committees, whose members are carefully vetted and selected to marginalize any input skeptical of the Party line of looming climate disruption.
“Carbon” is only a cover story for the UN’s true [and thoroughly immoral] motive: extracting the wealth of the West based on a completely unproven scare story, and handing our national wealth over to corrupt regimes – after first taking its own hefty cut. That is the fraud which we must fight.
What if the Upanishads and Vedas aren’t fiction but in fact historical works and what if there were in fact Human Civilizations in those times that also emitted C02. Maybe there’s also a mechanism that when the earth heats up too much it causes volcanoes to release cooling clouds. Weird theory night tonight.