# The Mathematics of Carbon Dioxide Part 2

Guest essay by Mike Jonas

Introduction

Part 1 of the series (Part 1) is here

In Part 1, simple mathematical formulae were developed to emulate the carbon dioxide (CO2.) contribution to global temperature change, as represented in the computer climate models.

This article uses the formulae to have a look at the Medieval Warming Period (MWP) and Little Ice Age (LIA).

Note : This article does not say anything new, or claim to find any new results. It has all been said many times before. But by using simple formulae that emulate the internal workings of the computer climate models, it allows the CO2 and non-CO2 components of global temperature change to be quantified using a spreadsheet [10] instead of a sophisticated climate model.

Please note : In this article, all temperatures referred to are deg C anomalies unless otherwise stated.

IPCC Report 1990

The 1990 IPCC Report contained the following graphic [1]:

In later IPCC reports, this graph was missing, and the MWP was either shown as much less significant or not shown at all. Considerable effort has been expended by climate scientists on trying to establish whether the MWP and LIA actually existed globally, or whether they were simply local to Europe and North America. There has also been a lot of discussion about whether climate scientists have tried to “get rid of” the MWP. For example, David Deming’s statement [2] to the US Senate in 2006 includes :

I had another interesting experience around the time my paper in Science was published. I received an astonishing email from a major researcher in the area of climate change. He said, “We have to get rid of the Medieval Warm Period.”

There is actually a lot of evidence that the MWP existed and that it was global. For example, places outside Europe and North America where evidence of the MWP has been found include Antarctica [3] [4], China [5], Peru [6], the Pacific Ocean [7], and many other places [8].

It is worth noting that, whereas the existence of a global MWP is generally accepted but is disputed in some quarters, the existence of the LIA is generally accepted and there is little or no dispute.

Why get rid of the MWP?

So … why does it matter so much whether the MWP existed, and whether it was global?

The problem that a global MWP poses is that it is incompatible with the climate models, which focus almost exclusively on CO2. The contribution of CO2 to global temperature during the MWP and LIA is easily calculated using the formulae developed in Part 1.

First, the data: CO2 data for this period is from Law Dome in Antarctica [9].

It is pretty obvious, just looking at the graph, that CO2 would have had little influence during this period, but its contribution can be quantified using the formulae developed in Part 1:

The CO2 contribution is as calculated in climate models, using an Equilibrium Climate Sensitivity (ECS) of 3.2 (including all feedbacks).

Figure 3 shows very clearly why the promoters of the computer climate models were so keen to get rid of the MWP : it demonstrates that the computer climate models are incapable of representing the climate. The impact of CO2 on the whole of the MWP and LIA periods was utterly trivial. CO2 even went in the opposite direction at times – rising while the temperature fell, and vice-versa. The models’ big upturn in CO2 contribution in the 20th century is not reflected in the temperature after 1939.

Conclusion

The picture of global temperature and its drivers as presented by the IPCC and the computer climate models is one in which CO2 has been the dominant factor since the start of the industrial age and other factors have had minimal impact. In order to support this picture, the IPCC has sought to portray CO2 as having been an important driver of global temperature in the past.

The idea that CO2 has been an important driver of global temperature is not supported by the evidence from the MWP and LIA (905 to 1977).

Footnote

It is important to recognise that the formulae used here represent the internal workings of the climate models. There is no “climate denial” here, because the whole series of articles is based on the premise that the climate computer models are correct, using the mid-range ECS of 3.2.

Mike Jonas (MA Maths Oxford UK) retired some years ago after nearly 40 years in I.T.

References

[1] 1990 IPCC Report section 7http://ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf Figure 7.1(c).

[2] David Deming’s statement to the US Senate Committee on Environment & Public Works. http://www.epw.senate.gov/hearing_statements.cfm?id=266543

[3] Hemer, M.A. and Harris, P.T. 2003. Sediment core from beneath the Amery Ice Shelf, East Antarctica, suggests mid-Holocene ice-shelf retreat. Geology 31: 127-130. http://geology.gsapubs.org/content/31/2/127.abstract

[4] Zunli Lu et al. 2012. An ikaite record of late Holocene climate at the Antarctic Peninsula. Earth and Planetary Science Letters. doi:10.1016/j.epsl.2012.01.036 http://www.sciencedirect.com/science/article/pii/S0012821X12000659

[5] Yan, H., Sun, L., Shao, D., Wang, Y. and Wei, G. 2014. Higher sea surface temperature in the northern South China Sea during the natural warm periods of late Holocene than recent decades. Chinese Science Bulletin 59: 4115-4122. http://link.springer.com/article/10.1007/s11434-014-0317-3

[6] Thompson et al. 2006 Jun 30. Abrupt tropical climate change: Past and present. doi: 10.1073/pnas.0603900103 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1484420/

[7] Yair Rosenthal1, Braddock K. Linsley, Delia W. Oppo. Pacific Ocean Heat Content During the Past 10,000 Years. Science 1 November 2013: Vol. 342 no. 6158 pp. 617-621 DOI: 10.1126/science.1240837 http://www.sciencemag.org/content/342/6158/617

[8] Papers on the MWP as Global Event. https://agwobserver.wordpress.com/2009/09/08/papers-on-the-mwp-as-global-event/

[9] Ice Core results: Law Dome CO2 and CH4 records of the last 1000 years first published in Etheridge et al., 1996 and 1998. [..]

Etheridge, D.M., L.P. Steele, R.L. Langenfelds, R.J. Francey, J.-M. Barnola, and V.I. Morgan. 1996. Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn. Journal of Geophysical Research, 101, 4115-4128.

Etheridge, D.M., L.P. Steele, R.J. Francey, and R.L. Langenfelds. 1998. Atmospheric methane between 1000 A.D. and present: evidence of anthropogenic emissions and climatic variability. Journal of Geophysical Research, 103, 15979-15996.Law Dome Ice Core 2000-Year CO2, CH4, and N2O Data. ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/law/law2006.txt

[10] Spreadsheet “Part2” with all data and workings – Part2 (excel .xlsx file)

Abbreviations

AR4 – (Fourth IPCC report)

AR5 – (Fifth IPCC report)

CO2 – Carbon Dioxide

CWIS – CO2 warming already in the system

ECS – Equilibrium Climate Sensitivity

IPCC – Intergovernmental Panel on Climate Change

IR – Infra-red (Radiation)

LIA – Little Ice Age

MWP – Medieval Warming Period

SKS – Skeptical Science (skepticalscience.com)

WRI – World Resources Institute

## 178 thoughts on “The Mathematics of Carbon Dioxide Part 2”

1. Richard Petschauer says:

Was not the temperature rise during the MWP a lot more than only about only 0.38C as shown in Fig 2? Would this small of warming amount allow Vikings to farm in Greenland for over 100 years?
It looks like someone who provided this data is trying to acknowledge the MWP, but diminish its importance.

• richard verney says:

For the Vikings to have successfully farmed Greenland with their primitive technology for hundreds of years, the areas settled would have had to have been many degrees warmer than today. It is more likely that temperatures would have had to have been closer to those of today at the say the Faroe Isles.
A few years ago, the UK had a very cold and harsh winter and it devastated hill farming in the Scottish Isles/Scottish highlands, and it is difficult to see how the Vikings could have survived just a few harsh winters since animal stock requires a lot of water.
I have often suggested that a farming expert should comment upon the sort of conditions required bearing in mind the limited and basic technology available to the Vikings.

• Richard Petschauer says:

So it looks like basing things on IPCC reports cannot be always trusted. They appear to be finally recognizing the MWP, but not really.

• MikeB says:

Mike
I think Richard is referring to figure 2, not the IPCC diagram which doesn’t have any vertical scale at all. You don’t state what period the anomalies are with respect to.
The difference between the MWP and the LIA on Fig.2 seems to be about 1.2 deg.C. Allowing for polar amplification this is not inconsistent with other proxies.
http://www.nipccreport.org/articles/2010/dec/Ljungqvist2010b.jpg
P.S. Thanks for the posting.

• MikeB says:

They appear to be finally recognizing the MWP, but not really.

They are not really admitting it. This was a graph they included in the first IPCC report, before they realised that it was necessary ‘to get rid of the putative Medieval Warm period’ because it was ‘diluting the message’. So, in subsequent publications, they hailed instead the infamous Hockey Stick Graph as produced by Michael Mann after some really amazing statistical manipulation. In so doing, they achieved ‘A New Low in Climate Science’, and there has been no looking back.
http://www.john-daly.com/hockey/hockey.htm

• “Steve McIntyre does the detective work here”
And what he suggests is that it is a smoothed version of a CET (England) measure, dating from about 1965. He also thinks the missing axis intervals are 0.5C, not 1 as you have it.
It’s not much to use as your sole authority.

• Mike Jonas says:

Nick Stokes – The IPCC version (Figure 1) is unscaled, so I went looking for a scale. I found a scale here – http://wattsupwiththat.com/2010/03/10/when-the-ipcc-disappeared-the-medieval-warm-period/ – as you can see in the spreadsheet Part2.xlsx, worksheet MWP. I then checked it against Steve McIntyre’s Figure 2, and it matched. Seemed pretty reliable. At every step in this process, I have sought to cross-check everything.
You say “He also thinks the missing axis intervals are 0.5C, not 1 as you have it.“. He doesn’t. What he says is “Next here is a plot of the Lamb CET together with Hans Erren’s digitization of IPCC 1990 Figure 7c (this digitization interprets the hash marks on the IPCC 1990 diagram as degree C intervals, as is clearly indicated in the caption and commentary, though even this is contested by Connolley).“. [My emphasis]

• Mike,
“as is clearly indicated in the caption and commentary”
I can’t see anything in the caption. The part in the commentary is probably this, where SM bolded the first part but not the second:
“The period since the end of the last glaciation has been characterized by small changes in global average temperature with a range of probably less than 2 deg C (Figure 7.1) though it is still not clear whether all the fluctuations indicated were truly global.”
Sounds like a dicey basis for using it as a global measure.

• george e. smith says:

The beautiful thing bout plots of temperature anomalies, is that it completely and permanently gets rid of information about Temperature differences, between different places at any moment in time.
Since the flow of thermal energy in the form of heat; whether conductive or convective, is a direct consequence of temperature differences over distance, I don’t see how one can argue that any of this relates to any sort of real physical system, with heat flows, such as occurs in the real world.
Kevin Trenberth et al, model earth’s energy flow as that which occurs on a perfectly isothermal planet, where every surface point is at a constant temperature of +59 deg. F or + 15 deg. C or 288 kelvin.
So completely missing from their model of planet earth is any information about the astronomically large amounts of heat energy that are transported from the tropics to the poles, to reduce the temperature differential that would exist, if there were no such heat flows, and polar Temperatures were entirely dependent on polar insolation.
As it is, on any ordinary midsummer northern day, the actual range of simultaneous temperature values on earth is typically 100 Kelvin or deg. C or 180 deg. F.
And it could be in the extreme, 50 % greater than that, or 270 deg. F Temperature range (American) of 150 kelvin.
Multimillions of dollars are being wasted on statistical numerical origami exercises, trying to confirm that 150 years ago, Trenberth’s isothermal planet was only +58 deg. F temperature..
In Mike B’s graph below, there is a blue gray band, and a black line that presumably is a consequence of applying the statistical algorithm, that when applied to a 100 mm square of paper, converts it into a frog that can jump.
Interesting, if you like paper jumping frogs, but not of much use to the poet, who would have written a Haiku or a sonnet, on that same piece of paper.
There are other statistical origami algorithms one can use that will reduce Mike B’s multicolor graph down to a single number that came from nowhere, and is going nowhere else.
As New Zealand’s most famous scientist (not Kevin Trenberth ) said :
“If you have to use statistics, you should have done a better experiment . ”
Ernest (Lord) Rutherford.
I presume, that the gray band part of Mike B’s graph, is actually a plot of a very large number of numbers that somebody originally had, that they acquired by some means.
I hesitate to say they were “observations” or the result of experimental measurements. Probably, there is nobody whom you could call up, or e-mail and ask exactly how they came by just any single one of those numbers. And all of that effort was for naught, (or nought), since it is simply thrown away to be replaced by a point on the black line, which clearly was never observed at any time in any place by anybody; so it is all complete fiction.
Well all of mathematics is fiction, and statistical mathematics, is more fictional than most.
But it is universal, in that the only requirement is that it be performed on a finite set of real numbers; those terms having their ordinary mathematical definitions.
There is NO other restriction on the numbers of the set; and there is no requirement, that any two of the set members are related in any way. The source of the numbers in the set is quite irrelevant, and the results are always exact, since each set member is exactly known, and only simple arithmetic concepts are needed. Furthermore, the statistical results may not even be numbers that are members of the set.
For example if you calculate the average of the telephone 10 key digits; their total is 45, for the ten numbers, so the average is 4.5, which is not even a member of the set.
And as for numbers which are NOT members of the set; the result of the statistical prestidigitation tells you nothing at all, about any number that is not a member of the set.
But it is almost as interesting as folding that paper, and getting a swan, instead of a jumping frog.
g

• Mike Jonas says:

Nick Stokes – OK, we have established that the temperature scale is correct and that Steve McIntyre did say that it was clearly shown. Now your quibble is over whether the temperature fluctuations were global. In writing these articles, I have spent a lot of time cross-checking everything. Everything. That’s why, in the article, you will see multiple references that provide evidence that the MWP was indeed global and was not confined to just Europe and North America : “places outside Europe and North America where evidence of the MWP has been found include Antarctica [3] [4], China [5], Peru [6], the Pacific Ocean [7], and many other places [8].“.
I find it really interesting that the temperature fluctuation of the LIA was similar in magnitude, yet no-one, not even you, appears to challenge its existence. The LIA, too, was not caused by CO2.

• Mike,
“OK, we have established that the temperature scale is correct and that Steve McIntyre did say that it was clearly shown.”
Where? SM said that the scale was clearly indicated in the caption and the commentary. But the caption merely says:
Figure 7.1.Schematic diagrams of global temperature variations since the Pleistocene on three time scales (a) the last million years (b) the last ten thousand years and (c) the last thousand years. The dotted line nominally represents conditions near the beginning of the twentieth century.
And I can’t see any clear indication in the commentary. Maybe your thorough checking can point to it?
But the key thing in the caption is “schematic diagram”. So now you are using it as hard data?
As to global, well, SM thinks it is CET, with specific doubts expressed in the source as to whether it applies globally. Just saying that evidence of MWP has been found elsewhere gives no basis for figuring a global average.
And yes, it’s likely that most of the fluctuations of the millenium up to say 1800 were due to things other than CO2. That doesn’t mean forcing a CO2 increase won’t cause warming.

• TimTheToolMan says:

Nick writes “And yes, it’s likely that most of the fluctuations of the millenium up to say 1800 ”
So you think that, say, after 1800 humans were the dominant forcing for climate change with their CO2 output. Really Nick? Really?

• Mike Jonas says:

In this article, only the CO2 data is from Law Dome.

• John says:

Temperature? Doesn’t the issue relate to distribution of energy within the global climate system and related states of change over time?
The object from AR1 – present is to project/estimate human impact on a climate system science doesn’t fully understand.
The computer models are incapable of hind-casting because the system isn’t fully understood.
Maybe I’m missing the point?

• John says:

Master Jonas,
Purely theoretical fun, is there a system in math which is suited to the meander in nature?
The only one I’ve ever found insightful is calculus. Use physics for the variables and its function.
Odd calculus can define a meandering river?
Best,
John

• notfubar says:

Of course that last figure implies that if not for the amount of CO2 we’ve added to the atmosphere, we’d be headed into another deep freeze like the LIA. Read “Fallen Angels” written in 1991 by Niven & Pournelle if you want a prescient take on our current situation – it was originally meant to be Science Fiction, but now hits too close to reality. [ http://www.amazon.com/Fallen-Angels-Larry-Niven/dp/0743471814/ref=sr_1_3?s=books&ie=UTF8&qid=1438112966&sr=1-3&keywords=fallen+angels ]

2. Lance Wallace says:

Two of the worksheets in the Part 2 Excel file (calsk and H2OTemp) show #REF! entries everywhere.
Averaging column B in Hadcrut 4 from 1961-1990, I don’t get 0.0000, but rather -0.00063. Perhaps this is just rounding error.
I was unable to work with the Part 1 Excel file, getting the message that it requires a macro that is unavailable. Since we were specifically instructed to disable all macros, this was unhelpful.

• Mike Jonas says:

I’ll see if I can find out what’s going wrong. The bit about using macros is tricky – running a macro in a spreadsheet leaves you wide open and although I wouldn’t put anything nasty in there I can’t guarantee that once it’s out of my control someone else won’t. There is optimising software out there which can be used instead, it’s just that I diidn’t use it.

• Mike Jonas says:

re: Hadcrut4 1961-1990. Met Office says “Time series are presented as temperature anomalies (deg C) relative to 1961-1990.http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/download.html
I’d say just rounding error. I have to work with what they provide – for what I’m doing here I obviously can’t fiddle with their data in any way.
(#REF’s still to be looked at)

• Mike Jonas says:

The worksheets with the #REFs aren’t used – I should have cleaned them out before posting. A cleaned-up spreadsheet is on its way. Everything that is used looks OK.
About the optimising : I’ve been thinking about how I can present the spreadsheet without an optimisation process (not easy, because at some point an optimisation is needed). I think I can do it, but not sure if I can get it done in time to be helpful.

3. Rico L says:

Read it again – “The problem that a global MWP poses is that it is incompatible with the climate models, which focus almost exclusively on CO2. The contribution of CO2 to global temperature during the MWP and LIA is easily calculated using the formulae developed in Part 1.”

4. Is 3.2 in watts/m^2? Compare that to the energy flows/densities in most typical climate heat balances. 3.2 might show up in the decimal points.

• Mike Jonas says:

3.2 is the Equilibrium Climate Sensitivity (ECS). It’s in degrees C and is the supposed global warming that a doubling of atmospheric CO2 concentration would cause. It’s the mid-range figure provided in the IPCC report AR4. In the context here, I have to work with the fgure that they provide.

• Joel O'Bryan says:

Live in a world fantasy you do.
– Yoda

One plus, you score

5. jamie says:

There is a lot of historical evidence the MWP existed and was warmer than temperatures of today. When climate scientists and the ipcc deny this fact it only shows that they cannot be trusted to properly perform the scientific method. They need to acknowledge its existence and explain it with science.

• Jack says:

The average dates of grapes harvest as they were booked in Burgundy’s archives show that during the MWP the harvest could occur as early as by the end of august in that region. According to some vine specialists, a 1.5° C warmer than today climate could explain this.

• Crispin in Waterloo says:

Jack, that is a scientific estimation. Crop physiology and chemistry is pretty well understood. It is difficult to claim that a particular crop evolved to ripen earlier then devolved again to ripen later. It must have been consistently warmer.
Without global warming the conquests and empire of the Mongols would not have been possible. When it is warmer Central Asia is wetter. I can’t see why Nick Stokes is still flying the Team’s flag of ‘MWP was regional’. It wasn’t, isn’t and won’t be in future. Can we please move on?

6. richard verney says:

Due to the lack of land massses in the SH, and due to the relatively primitive civilisations in the vast majority of the SH, there is less evidence/archaelogical evidence/written evidence for the MWP in the SH, although lack of evidence does not prove something did not exist/happen.
Leaving aside the status of evidence (and there is some evidence suggesting that the MWP was global), what is the physical explanation for the MWP being confined to just the Northern Hemisphere? I have never seen any convincng explanation offered as to how (or what) caused significant warming for an extended period limited to one hemisphere.
I would like to hear from those who question the global nature of the MWP, what caused the NH warming and why this did not cause similar warming in the SH.

• Sun Spot says:

I would also like to here the explanation as to the meteorological conditions that could somehow cause a warm air mass to hang over the NH (or northern Europe only) for about 300 years ?? Amazing how the magical thinking of the cAGW acolytes accept the tosh that the MWP was only northern hemisphere or even only European.

• oppti says:

Solar brightening occurs mostly in the NH during late 1900.

• richard verney says:

The SH has disproportionately more ocean, and oceans dampen the response. Thus it is not surprising in itself to see differing response/response times between the hemispheres over short periods.
The point is that the data covers only a very short period. Could the present day trend last 300 years, or is it just a coincidence of oceanic cycles which cycles may lead to a cooling/ or slower rate of warming in the NH in coming years?
Further the MWP resulted in more than just fractions of a degree of warming, at any rate over some of the land mass in the NH.
But like all things in Climate Science, one is grappling with poor quality data, lack of relevant data, and proxy data (which is nigh on impossible to properly tune and at most is indicative only) and hence everything is very uncertain and subject to substantial error bounds (which Climate Scientists fail to properly acknowledge)..

• Brett Keane says:

Richard, the land of Rutherford is not so primitive, and has excellent pollen/volcanics temperature proxies and datings which prove the MWP and LIA etc., for starters.

7. Ted G says:

Mike.
Thanks for this excellent and enlightening post, It’s to the point and easy to understand.
Many thanks.

8. “The idea that CO2 has been an important driver of global temperature is not supported by the evidence from the MWP and LIA (905 to 1977).”
There is no logic there. Your evidence about the MWP is a freehand sketch of unknown origin from 25 years ago (scale not numbered, and region not stated) , and ignores all that has been found out since. Then you compare that with what you imagine a GCM might provide.
CO2 may have been an important driver (quotes?), but no-one is saying that nothing else affects temperature.
Here, from here, is a comparison using real (not cartoon) reconstructions, and real GCM output. They match pretty well.
http://www.moyhu.org.s3.amazonaws.com/misc/paleo/medieval.png

• Charles Nelson says:

The Medieval Warm Period exists because there is much in the way of factual and documentary evidence to prove that it existed.
A graph that claims to represent temperature shifts of 1/10 of one degree C!!!! in the year 900AD (created using proxies models and reconstructions) is almost touchingly pathetic in the face of hard evidence.
Just how many Angels CAN dance on the head of a pin these days….I wonder?

• Nick,
Depends of which temperature reconstruction you use to compare with. The above model ensemble fits mainly the MBH’98 and similar reconstructions of only a few tenths of °C difference between MWP and LIA.
If you compare them with most European reconstructions (Moberg, Esper, Huang,…), the difference is around 0.8°C and CO2 is not the main driving factor for the changes.
Take the opposite view: temperature drives (pre-industrial) CO2 levels, the high resolution (~20 years) Law Dome ice core shows a drop of ~6 ppmv between MWP and LIA, which can be caused by a 0.8°C drop in temperature, taking the 8 ppmv/°C change over the past 800,000 years in ice cores as base. The drop in CO2 follows the main drop in temperature with a lag of ~50 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
Conclusion from several European reconstruction specialists:
http://www.blogs.uni-mainz.de/fb09climatology/files/2012/03/Esper_2005_QSR2.pdf
So, what would it mean, if the reconstructions indicate a larger (Esper et al., 2002; Pollack and Smerdon, 2004; Moberg et al., 2005) or smaller (Jones et al., 1998; Mann et al., 1999) temperature amplitude?
We suggest that the former situation, i.e. enhanced variability during pre-industrial times, would result in redistribution of weight towards the role of natural factors in forcing temperature changes, thereby relatively devaluing the impact of anthropogenic emissions and affecting future predicted scenarios.

Meanwhile it gets clear that the driving forces attributed to CO2 (with positive feedbacks) and aerosols (as negative balance) in most climate models are largely overblown, as the current “pause” shows…

• “CO2 is not the main driving factor for the changes”
But who thought it would be? That’s my objection to the logic, which says that because more CO2 will cause warming, therefore warming must be caused by CO2. In fact, in that plot you see the main dips caused by volcanoes. In the paper I linked, they do look at various factors, and think that the LIA drop may have been largely caused by volcanoes:
“Analysis of the global energy budget during the last millennium indicates that Little Ice Age (LIA) cooling is largely driven by volcanic forcing (comprising an average of 82%, 54% and 77% of the total forcing among models for the 1200-1450 CE, 1400-1650 CE and 1600-1850 CE periods, respectively, relative to 950-1200 CE), while contributions due to changes in total solar irradiance (15%, 30% and 10%) and greenhouse gas concentrations (3%, 16% and 13%) are substantially lower. “
For CO2 to drive warming, something has to drive CO2, and in that time, it’s not clear what that could be, though there were some land use changes.
As you have often said, while temperature change affects pCO2, the effect is small relative to recent CO2 rise, and it is a different mechanism (solubility, not radiative).
“as the current “pause” shows”
I think the word is recent.

• Nick,
You are right, the impact of the CO2 changes of the past was relatively small, while most CO2 changes were temperature induced.
Most models include a relative huge impact from CO2 – with feedbacks – and aerosols on temperature, reason why the real impact of volcanoes in that study are beyond what is observed (as far as the proxies are following the different impacts).
A smaller CO2-aerosol impact tandem still may explain the past, as most of the variability of the past is natural, where e.g. clouds and ocean oscillations are wrongly implemented (positive in models, negative in the real world) and ocean oscillations are completely absent or underestimated. That makes that calculations only based on radiative forcing are doomed to go wrong.
What is sure is that most models now have a too high sensitivity for 2xCO2 and accordingly for aerosols (as both are needed to explain the 1945-1975 cooling).

• Glacierman says:

Nick,
In response to your statement – “CO2 may have been an important driver (quotes?), but no-one is saying that nothing else affects temperature. ”
How about NASA? – Lacis, A.A., G.A. Schmidt, D. Rind, and R.A. Ruedy, 2010: Atmospheric CO2: Principal control knob governing Earth’s temperature Science, 330, 356-359, doi:10.1126/science.1190653.
http://www.giss.nasa.gov/research/briefs/lacis_01/
Governing Earths temperature is a little stronger wording that being an important driver. Schmidt, et al say it controls Earths temperature. The data does not support that conclusion.

• That Lacis paper is saying that CO2 has a powerful effect on the climate, particularly relative to other gases. But the thing about a control knob is that someone has to turn it, else it does nothing. Something has to actively force CO2 into the atmosphere for it to have an effect. That is happening now – in earlier times the main CO2 forcing was from volcanoes, but they also produced aerosols, which had a stronger effect for a while. The only other time-varying factor pushing CO2 into the air was heat itself, through effect on solubility.
You may have a control knob on your heater. But if you never touch it, then the house temperature still goes up and down in response to other things – mainly outside weather.

• David A says:

Control nob? Strange that thermostat in my alarmist house. It ten degrees outside, freezing inside, and the heater is off. Suddenly my house gets warm over a short period. Later I get up and turn the heater on.

• Nick,
Even in the link to the Atwood e.a. study, they give a few reconstructions which show much more variability than what is compared to for the models: a ~3°C drop in seawater temperature of the NE Atlantic Ocean, the 2009 Mann e.a. NH reconstruction which shows a 0.5°C temperature drop (including the upside down use of some proxies, as discussed by Steve McIntyre), far beyond the few tenths drop in the “ensemble” reconstruction.
Moreover, the not referenced Frank e.a. range of reconstructions were meant to calculate the CO2 change from temperature change, not the other way out:
http://www.ncdc.noaa.gov/paleo/pubs/frank2010/frank2010.html
Within the “ensemble” range you can have any reconstructed MWP-LIA temperature change between -0.2°C and -1.2°C…
Seems to me that Atwood e.a. just cherry-picked the low-amplitude reconstruction that fitted the model ensemble…

• Ferdinand,
“Moreover, the not referenced Frank e.a. range of reconstructions”
Not referenced? He uses Frank’s collection, as referenced in the caption and elsewhere. It’s not Atwood’s “cherry-pick”.
That average will show less variation than individual recons. But the same is true for the model average.

• Nick,
The Frank e.a. paper was not in the reference list of Atwood, but was easily found in the literature.
The main problem of the Atwood paper is that he seems to have used the median of the reconstructions, which is heavily weighted to the low-amplitude versions, which all use the same suspect proxy series (strip bark bristlecones,…), see:
https://climateaudit.files.wordpress.com/2009/01/indepe1.gif

• Keith Willshaw says:

The provenance of the graph was clearly stated , it appeared in the IPCC 1.0 report in 1990 and was IRC prepared by Hubert Lamb at the UEA based on the actual proxy evidence available. There are literally hundreds of peer reviewed papers that make it clear that both the MWP and LIA were real.
Computer models are only useful if validated, as of today their record on predicting the future is abysmal That it was possible to tweak one to ‘predict’ past events is unsurprising. Its like a racing tipster trying to prove he can tell which horse will win tomorrow by giving you the list of yesterdays winners.
GCM output is NOT real, its a best guess based on the parameters that it was programmed with.
Records of growth patterns across Europe and North America ARE real. We know that the end of the MWP brought famine and disease to Northern Europe as the records survive.
https://en.wikipedia.org/wiki/Great_Famine_of_1315%E2%80%9317

• Keith,
“was IRC prepared by Hubert Lamb at the UEA based on the actual proxy evidence available”
Keith Jonas linked above to Steve McIntyre. He suggests it is a smoothed version of a 1965 plot by Lamb of CET “estimates”. Not global, and there were hardly any proxies then.
Just because you firmly believe in a MWP and this shows a MWP doesn’t make it right. Even the axis interpretation here seems to be wrong.

• David A says:

“There are literally hundreds of peer reviewed papers that make it clear that both the MWP and LIA were real”
===================================
And without so much as a how do you do, Mann erased all those papers. The graphs Nick shows with the MWP slowly entered back in, but not to the degree that the evidence indicates, were forced in, accepted reluctantly by the IPCC. The “team” proxy reports are a comedy/tragedy of errors. Nick disparages the original graphic in the IPCC because it was not computer drawn. Computer generation only insures a quicker answer, not a more correct one. Much evidence since that graphic support it, not the forced watered down crawl back from the hockey-stick.
Mike J, I suggest “CO2 science” as an excellent source on information and papers regarding the MWP.

• TimTheToolMan says:

Nick writes “Just because you firmly believe in a MWP and this shows a MWP doesn’t make it right. ”
Archaeology trumps proxy temperature reconstructions Nick. There were people in Greenland in the MWP and Greenland’s climate could support them. If you want to argue that it was regional warming that lasted hundreds of years then feel free. There are some very interesting climate change implications down that line of reasoning.

• HAS says:

Nick
Run that past me again using absolute tempertures.

• Chris Wright says:

Nick,
The match in the graph is pretty good. They both show a similar overall trend of cooling that corresponds to the LIA.
So, if the models accurately predicted the past trends, then it implies that the models “knew” what caused the trend. And in turn it implies that the scientists who created the models “knew” what caused the trend. So, do they know what caused the cooling trend?
If I were a cynic – which thankfully I’m not – I might think they had simply “adjusted” the models in order to agree with the proxy data.
You don’t have to be an Einstein to forecast the past!

• I quoted above from the Atwood paper, which says what they believed caused the trend. Mostly volcanoes.

• Chris,
It was reverse: they used the trend from a (simulated?) reconstruction with very little difference between MWP and LIA. If they had used Moberg or Esper or some other reconstruction which has about 0.8°C cooling between MWP and LIA, there was no match at all…

• David A says:

I think they use a combination of both a watered down MWP, and inappropriate use of other forcing’s such as volcanoes.
If they truly had the past correct, then their future predictions would not be so off the rails.

• Nick, you imply you do not believe in the MWP. I’m sure you believe it was regional, correct? So what region counteracted that warming with cooling to keep global temps even? If no cooling region existed then a warming region anywhere would be noticeable on a global scale. Where I live there has been 0 warming in the last 100 years, and guys like you claim that my region doesn’t matter because another region received warming, and you do not call that regional warming, but instead you call it global warming. So Nick, where was the region with cooling to counter the warming in the NH during the MWP?

• I have no preconceived views on the MWP. Quite a lot of recons show some, including the one I showed above. It may have been regionally stronger in Europe etc; that doesn’t have to be balanced by cooling elsewhere.
But as I said above, arguing that the above cartoon must be right because it shows a MWP and we just know there was one, makes no sense.

• Nick Stokes

I have no preconceived views on the MWP. Quite a lot of recons show some, including the one I showed above. It may have been regionally stronger in Europe etc; that doesn’t have to be balanced by cooling elsewhere.

The CAGW government-academic crowd immediately and completely accepts and believes every single peer-reviewed “paper” that promotes their world view about future CO2 increases, postulated future CO2 effects on future global average temperatures, the potential effect of potential future temperature increases on any and all creatures, plants, and sealife now on earth, and immediately promotes any peer-reviewed paper that calls for the world’s economic death by artificially limiting energy availability. Even ONE paper is enough to be believed in its glorious entirity of gloomy predcitions, no matter how nebulous or far-fetched the paper’s assumptions.
Thus my question: How many peer-reviewed papers do you (personally and individually) require to be convinced that the MWP and the subsequent Little Ice were (1) global in scope and (2) have been absolutely and scientifically well established by proxies and analysis as a multi-century natural warming phenomena from 500-700 AD up to a warm period between 1000-1200 AD, then dropping to a cold period in 1650, then rising back towards today’s Modern Warm Period?

• Mike M. (period) says:

RACookPE1978,
You wrote: “How many peer-reviewed papers do you (personally and individually) require to be convinced that the MWP and the subsequent Little Ice were (1) global in scope and (2) have been absolutely and scientifically well established by proxies and analysis as a multi-century natural warming phenomena from 500-700 AD up to a warm period between 1000-1200 AD, then dropping to a cold period in 1650, then rising back towards today’s Modern Warm Period?”
Number of papers is, of course, irrelevant in science. One convincing paper trumps any number of poor papers. So, if you can provide me with references to one or more convincing papers supporting your claims, I will read them with interest. I mostly don’t mind if they are paywalled.
I have seen some papers claiming the opposite, but I have not found them convincing. Most scientific papers aren’t. That is the nature of science.

• Nick Stokes, Mike M. (period)

Number of papers is, of course, irrelevant in science. One convincing paper trumps any number of poor papers. So, if you can provide me with references to one or more convincing papers supporting your claims, I will read them with interest. I mostly don’t mind if they are paywalled.

Here are a couple hundred peer-reviewed papers establishing that (1) the Medieval Warming period IS a global phenomena and (2) that the data establishing its extent has been found on every continent and under every ocean floor. o exceptions.

• Mike M. (period) says:

RACookPE1978 ,
“Here are a couple hundred peer-reviewed papers establishing that (1) the Medieval Warming period IS a global phenomena and (2) that the data establishing its extent has been found on every continent and under every ocean floor. o exceptions”
Where?
If you said two papers, I’d be inclined to believe this a careless mistake. But several hundred? Withe no link or reference? That sounds like bullshit. If it is not, you won’t mind identifying the best two or three of those papers.

• Mike M. (period) says:

RACookPE1978,
You are just bullshitting. Claiming that there are papers saying what you say they say is not good enough. A link to a web site with links to a huge number of papers on a wide range of topics is not good enough. What would be good enough would be links to one or a few papers that you would like your argument to be judged by.

• David A says:

Mike, I do not think you are being fair to RA Cook’s comment, He gave you (his second link) a direct link to this page…
Medieval Warm Period Project
Project Overview
Study Description and Results
Africa
Antarctica
Asia
Australia/New Zealand
Europe
North America
Northern Hemisphere
Oceans
South America
MWP-CWP Quantitative Temperature Differentials
MWP-CWP Qualitative Temperature Differentials
Interactive Map and Time Domain Plot
To view this feature, your computer must be configured to run applets that use Java technology. To download and install free Java software, we recommend Sun Microsystems’ Java Runtime Environment, which is available at http://www.java.com. Instructions on how to operate the map’s features are located under the map. Scroll down after clicking on the link above to view them.
List of Scientists Whose Work We Cite
List of Research Institutions Associated With the Work We Cite
==============================================================
Now I opened the first one on Africa and found twenty papers. It would take many many hours to just study what is presented and studied here. You had a great link to a wonderful compilation of the research on the MWP. The link was there and it is convincing if one takes the time to research it. Nick Stokes clearly has not.

• David A says:

Mike, for instance here is just one study, http://www.co2science.org/articles/V3/N22/C3.php
Reference
Huang, S. and Pollack, H.N. 1997. Late Quaternary temperature changes seen in world-wide continental heat flow measurements. Geophysical Research Letters 24: 1947-1950.
What was done
The authors searched the large database of terrestrial heat flow measurements compiled by the International Heat Flow Commission of the International Association of Seismology and Physics of the Earth’s Interior for measurements suitable for reconstructing an average ground surface temperature history of the earth over the last 20,000 years. Based on a total of 6,144 qualifying sets of heat flow measurements obtained from every continent of the globe, they produced a global climate reconstruction, which, they state, is “independent of other proxy interpretations [and] of any preconceptions or biases as to the nature of the actual climate history.”
What was learned
From their reconstruction of “a global climate history from worldwide observations,” the authors found strong evidence that the Medieval Warm Period was indeed warmer than it is now, by perhaps as much as 0.5°C, which is only 0.1°C less than the peak warmth of the mid-Holocene Maximum. Their data also suggested that the Little Ice Age was as much as 0.7°C cooler than it is currently.
From CO2 science there are about two hundred papers listed (there are two sections, and I did not did them up, but it is extensive and well over one hundred for certain) which form the body of the scientific research over the last 35 plus years. RA Cook was not saying there are two hundred papers which all individually show the above, but that in combination, disparate papers when reviewed in total do make a very convincing case.

• Mike M. (period) says:

I am being completely fair to RACookPE1978. To cite everything is to cite nothing.

• David A says:

Mike says, “I am being completely fair to RACookPE1978. To cite everything is to cite nothing.”
========================================
Mike that is nonsense. It is not “everything”, it is an extensive review of the scientific literature, only rebutted by the paleo-proxy reports of the “team”. A scholarly review of the literature regarding THE MWP, both pre and post CAGW is very cogent to this post. It is not “nothing” as you assert without logic. I am sorry to see you take this path. CO2 science is an excellent site, and it just requires study, but it is 100 percent relevant to an understanding of the MWP.

• David A you post “strong evidence that the Medieval Warm Period was indeed warmer than it is now”

Two things about this puzzle me. One is that the MWP was longer in time span than the modern warming period. Now if the MWP was warmer than today, how come the tree stumps being uncovered at Glacier national park, at the edges of the melting glaciers carbon date back much further in the past than 1000 years?
..

• David A says:

Regarding glacier national park, not sure, but that is ONE location. Perhaps for disparate reasons the trees did not grow back there in that single location during the MWP, the shortest of the three main warming periods in this interglacial. BTW, they have yet to grow back today. However I must say it is curious that you pick North America in the North Hemisphere where the MWP is very well established. In the below list you will find both extensive proxy evidence, and archeological evidence that the MWP was likely warmer then today. If one wishes to understand the MWP they need to research the entire body of work on it. For this reason the CO2 website is an excellent resource.
Here is the papers supporting the MWP in the Northern America…
Level 1 Studies; Studies that allow a quantitative comparison to be made between the temperatures of the Medieval Warm Period (MWP) and the Current Warm Period (CWP). These reports are very important, especially those that reveal the MWP to have been warmer than the CWP.
Boniface River Area, Northern Québec, Canada
Boothia Peninsula, Nunavut, Canada
Chesapeake Bay, USA
Crête, Central Greenland
Donard Lake, Cape Dryer Region, Baffin Island, Canada
Dye-3, Southern Greenland
Eastern Sierra Nevada Range, California, USA
Fog Lake, Baffin Island, Canada
GISP2 Ice Core, Central Greenland
GISP2 Ice Core, Greenland Summit
Great Bahama Bank, Straits of Florida
GRIP Ice Core, Greenland Summit
Hallet Lake, Alaska, USA
Iceberg Lake, Alaska, USA
Jenny Lake, Southwest Yukon Territory, Canada
Lake 4, Southampton Island, Nunavut, Canada
Lake Erie, Ohio, USA
Lake WB02, Northern Victoria Island, Nanavut, Canada
Lower Murray Lake, Ellesmere Island, Nunavut, Canada
Moose Lake, Wrangell-St. Elias National Park and Preserve, South-Central Alaska, USA
Pigmy Basin, Northern Gulf of Mexico
Upper Fly Lake, Southwest Yukon Territory, Canada
Level 2 Studies
Blue Hole, Lighthouse Reef, Coast of Belize
Carmen Basin, Gulf of California
Cayuga Lake, Central New York, USA
Chappice Lake, Alberta, Canada
Dog Lake, British Columbia, Canada
Effingham Inlet, West Coast of Vancouver Island, British Columbia, Canada
Egedesminde Dyb, South-western Disko Bugt, West Greenland
Farewell Lake, Alaska, USA
Greenland Ice Sheet Project Two (GISP2), Central Greenland
Guaymas Basin, Gulf of California, Mexico
Hudson River Estuary, USA
Iceberg Lake, Alaska, USA
Igaliku Fjord, South Greenland
Kuujjua River Region, Western Victoria Island, Northwest Territories, Canada
Lake Mina, Minnesota, USA
Lamar Cave, Yellowstone National Park, Wyoming, USA
Lily Pond, General Creek Watershed, Sierra Nevada Mountains, California, USA
Lower Murray Lake, Canada
Nansen Fjord, Eastern Greenland
Nebraska Sand Hills, Western North America, USA
North American Great Plains, USA
Northern Range of Yellowstone National Park, Wyoming, USA
Northern Uinta Mountains, Northeastern Utah, USA
Owens Valley, White Mountains, California, USA
Pescadero Basin, Gulf of California, Mexico
Qipisarqo Lake, Southern Greenland
Raffles Sø, Liverpool Land, East Greenland
Raffles Sø, Liverpool Land, East Greenland
Rawson Lake, Northwestern Ontario, Canada
Royal Basin, Olympic National Park, Washington, USA
Selwyn Lake, Subarctic Canada
Sierra Nevada Mountains, California, USA
South Fork Payette River Area, Central Idaho, USA
Southern California, USA
Southwest Greenland
Tebenkof Glacier, Northern Kenai Mountains, Southern Alaska, USA
West Greenland Current, Off the West Coast of Greenland
Level 3 Studies
Aleutian Islands, Alaska, USA
Alfonso Basin, Gulf of California, Mexico
Amargosa Canyon, Death Valley, California, USA
Crevice Lake, Yellowstone National Park, USA
Disko Bugt, West Greenland
Elk Island National Park, East-Central Alberta, Canada
Heal Lake, Southern Vancouver Island, Canada
Hole Bog, Minnesota, USA
Hudson Estuary, New York
Igaliku Fjord, South Greenland
Lake Chichancanab, Mexico
Mexican Highlands
Minden Bog, Michigan, USA
Moon Lake, North Dakota, USA
Naja Lake, Lacandon Forest, Chiapas, Mexico
Nansen Trough, East Greenland Shelf
Narsaq Sound, Southern Greenland
Northeastern Portion of Yellowstone National Park, Wyoming, USA
Owens Lake, East-Central California, USA
Petaluma Marsh, Northern California, USA
Pickerel Lake, South Dakota, USA
Piermont Marsh, New York, USA
Republican River, Southwest Nebraska, USA
Shark Rive Slough, Florida Everglades, USA
Sierra de Manantlan Biosphere Reserve, West-Central Mexico
Sierra Nevada and White Mountains of California, USA
South Bay, Near San Francisco, California, USA
Southern Canadian Tundra, Southwestern Keewatin, Nunavut, Canada
Southern Sierra Nevada, California, USA
Steel Lake, North-Central Minnesota, USA
Upper Gunnison Basin, Colorado, USA
Western Pacific California Current, USA

• Joe says:

“Your evidence about the MWP is a freehand sketch of unknown origin from 25 years ago (scale not numbered, and region not stated) , and ignores all that has been found out since. ”
funny, how freehand sketches of unknown origin makes it into IPCC reports, then disappears without explanation as convenient, as with the Himalaya glaciers

• Mike Jonas says:

Nick – I was sure that someone like you would write something like that. That’s why I wrote Part 3.

• Brett Keane says:

Even using retropspection, CMIPS and similar cannot carry the adjective ‘real’.

• GregK says:

So cooling from about 100CE to 1815 or so on that graph.
What was going on in the Roman Empire ?
And presumably the point of it is to show that there wasn’t a MWP ?
Eric the Red would be surprised.

9. I did not notice a source being cited for the temperature curve in the Figure 3 graph. It shows a dip in temperature in the late 1800s, when all major instrumental records going that far back (including versions as old as HadCRUT2) show more of a bump than a dip. It shows a sharp uprise starting shortly 1900, while instrumental records show a noticeable dip centered around 1910 and a sharp uprise from the mid-late 1800s level starting around 1920. Can someone cite the source, or point out where I missed it if it was cited here?

• Mike Jonas says:

“CO2” in figure 3 is CO2’s contribution to temperature as calculated in the climate models. “Non-CO2” is what’s left over when you take “CO2” away from the temperatures in figure 1. “Non-CO2” dips in the late 1800s, because the climate models calculate more warming from CO2 than actually occurred (ie, if the climate models are correct then the non-CO2 contribution must have been negative). The same thing happens again after the 1930s.

10. If at first you don’t succeed, model, model again.

• Joel O'Bryan says:

Correct. Grant app’s get 3 tries with NSF.

11. Joel O'Bryan says:

Of course this discussion really begs the question of the Roman Warm Period, the Minoan Warm Period, and the Holocene Optimum. Each time it got warm, and then cold again with a steady overall cooling since the Holocene Warm period maximum 8000 ya. Today we are in the modern warm period. Our biggest problem is too many M’s.
The reality also is each of those more recent periods lasted some ~400 years, with a few downward spikes, before the clmate really turned cold again (D-O events and YD-like events). So our (relatively) puny modern warm period started in/around 1850 and may last until 2250-2350 before it turns really cold again. Unless the sun decides otherwise. Some say the sun dictates and it will 2600 before the next LIA v2. All are just Wild Ass Guesses, including the billion dollar CMIP5 ensemble.
Call it unpredictable. So we must Build for resilence. Build with nuclear power. Carry on.

• @ Joel O’Bryan
Good comment. I think you show a lot of common sense there. (is that allowed in climate “science”?)
As to nuclear power, we should go only thorium rather than the inefficient and dangerous bomb making types that the governments insisted on so far.

12. Dudley Horscroft says:

Depends where you have your starting point. The upper graph has a temperature peak in modern times in about 1931, at a temperature of just about 0.03C below the zero point on the right hand scale. But this includes the early 20th C warming, and omits the later 20th C warming. From about 1400 to 1900 the temperature was mostly about 0.45C below the reference temperature, and this should be the level that one would consider the base line. So really the temperature rise during the “100” years of so of the Viking settlement would have been more like 0.83C above the base line. Just now we are approaching the level reached during the MWP, and of course certain personages have trumpeted that the current temperatures have not been exceeded during the past 1000 years. It is possible that where suitable land has been exposed at sea level in Greenland, Viking style agriculture could now just about exist.
From the upper graph, the first Viking settlement in AD 986 was when the temperature was at -0.25 below the graph’s zero point. This level was again reached about 1380. The site
http://www.greenland-guide.gl/leif2000/history.htm states that by 1370 trade had been decreasing and the trade ship was lost in around 1380. Further, in 1397 “The Norwegian, Swedish and Danish kingdoms merge into the Kalmar Union. The supremacy and tax claims of Greenland are hereafter handled by the Danish court.” (Aha! I smell tax problems!) and the last written record was of a wedding in 1408. By 1500 the Norse population had disappeared or, more likely I would have thought, intermarriage with the Eskimos would have resulted in disappearance of a separate Norse ‘clan’. Cooling below the sustainable level led to loss of agriculture, and the remainder reverted to a hunter killer style existence. The colony was sustainable for about 400 years, rather than 100 as mentioned by Richard Petschauer.

• richard verney says:

As the Greenland glacier retreats, Viking settlements are still being discovered and much of the surrounding ground is perma frost. Presently, the Vikings would be unable to farm (using their old technology) in most areas where settlements have been found.

• Steve P says:

“and the last written record was of a wedding in 1408.”
Yes, but there’s more, and I can’t resist adding this, from Wikipedia:

The last reported ship to reach Greenland was a private ship that was “blown off course”, reaching Greenland in 1406, and departing in 1410 with the last news of Greenland: the burning at the stake of a condemned witch, the insanity and death of the woman this witch was accused of attempting to seduce through witchcraft, and the marriage of the ship’s captain…

https://en.wikipedia.org/wiki/History_of_Greenland
When the mild climate goes south, the witches burn…

13. Essentially the model’s position is that although CO2 had nothing to do with the MWP and the LIA (and for that matter any of the glacial/interglacial transitions for the last 800k years); not to mention the Ordovician and Carbo/Permian glacial periods, Does 1-50 in case I have forgotten more; that somehow human CO2 is a different animal…
Maybe. Very much looking forward to how you develop this.

14. Dudley Horscroft says:

Note my response at 9.57 pm was to Richard P’s response, then the only one. On posting it I find I was the 23rd respondent – this will make the 24th – or perhaps the 54th!

15. Steven Mosher says:

The Lamb chart from 1990 was wrong. As the climategate mails indicate it was included in the report
by Folland who wasnt aware that Lambs work had been refuted.
The reason he didnt realize it was that CRU had published the corrections to the chart in a unknown journal
to spare lamb the embarassement

• David A says:

Much subsequent work supports the tends found in Lamb.

• Sorry Mosher, but the IPCC is infallible.

• MikeB says:

Steve
Mr. Pachauri assured me and everyone else that IPPC reports are based on 100% peer-reviewed science from 1000s of meticulous scientists. Every line is scrutinised by governments around the world to weed out inaccuracies. The process relies on the debate being devoid of political taint and grounded in sound scientific knowledge.
It can’t be wrong can it? (It’s a bit late after we’ve wasted billions of dollars for 20 years on a wild goose chase)

• Walt D. says:

As the man (Mann?) said – the science is settled.

• David A says:

Lamb was not wrong as much as it was sparse. Anyone can go to CO2 science to find a listing of many papers from both hemispheres and the global oceans that support the Lamb graph far more then they support the “teams” tree ring studies, which are scientifically embarrassing.
Mosher embarrasses himself with his biased comments and willful ignorance of the literature.

16. co2islife says:

I would focus on the math that totally discredits the AGW theory. Here is a chart of the Holocene. Every chart looks like this. If Climate “Science” was a real science they would have conclusions dictated by the scientific method. All one needs to do is choose various ice core data sets from around the world and test the hypothesis “man is not causing climate change.” Answer the question “is the temperature variation of the past 50 and 150 years statistically different from the previous 15,000 years? Are we at a peak of the past 15,000? The answer to both those questions is no. How this counts as a real “science” is beyond me. Their conclusions contradict the conclusions given by the scientific method.
https://www.pressdispensary.co.uk/q991593/images/20k.jpg
The other key math analysis is how much energy is represented by the 13µ to 18µ band of IR? Is there enough energy in that narrow band to warm the oceans? If not, what is warming the oceans? Isn’t it likely that what is warming the oceans is also warming the atmosphere? That is check mate to the warmists.

• MikeB says:

Although ice-core records are useful in showing past temperature fluctuations long before any suggestion of human influence, you should have realised by now that ice-core records do not go up to the present day. They say nothing about present day warming or lack of it.
The trouble with presenting a misleading graph, which pretends to show the present day warm period when it doesn’t, is that it is counter-productive. It harms the sceptic cause, it doesn’t help it.
The plot seems to be based on Alley et al, 2000. The latest temperature data point for that is about 1910. The present day warming comes after that.
Be scrupulously truthful, even if the truth is inconvenient, for it is more inconvenient when you try to conceal it – Bertrand Russell

• MikeB,
Please tell me why ice-core records are useful for the past but not useful for the present. You failed to mention the reasons behind that statement.

• Actually the most recent data point for Alley et al is 99 yrs before present, which is 1950. So it ends 1855. No use for recent warming.

• MikeB says:

No Mark, I did mention it!!!

The latest temperature data point for that is about 1910. The present day warming comes after that.

I’ve noticed before that you have reading comprehension difficulties. Is that why you swallow the sky dragon nonsense?

• David A says:

Mike, also those graphics do not show decadal changes, so they really likely miss many many dozens of periods of higher warming, and lower cool periods.
You are correct, it is misleading for the message used, just as an alarmist tacking on the current warm period from thermometer readings would be highly misleading. It is not misleading to show the many changes in T not caused by CO2.

• Then add 1 degree to the end of the graph, it still puts present day below the MWP and below most of the last 10,000 years.

• rgbatduke says:

So it ends 1855. No use for recent warming.

Unless you compare current central Greenland temperatures and add a datapoint at the end.
Let’s see, that appears to be (from Kobashi et. al.) −29.9°C. Not entirely fair — high frequency and low frequency records and all that — but basically the warming looks a lot like that following the 8200 year cooling, in both magnitude and the time required, and is far slower than the warming that ended the YD.
Not arguing either side, understand. Personally I think that any assertion — no matter by which learned author — of a knowledge of temperatures prior to 1900 needs to come with enormous error bars, and that goes for global “anomalies” too, in spades. Before 1850 most of the world was still terra incognita, and oceana even more incognita. Asserting that a handful of proxies from a handful of sites are accurate enough to be of some use at the same time GISS and HadCRUT4 don’t agree within better than 0.1 C today, and when “adjustments” release to release still tally up to 0.1+ C alterations over the history of best estimates from global thermometric data, we know the global temperature in the MWP to what resolution, exactly? Maybe a whole degree C? Maybe not even that. And that too goes for the anomaly as well.
rgb

• co2islife says:

Although ice-core records are useful in showing past temperature fluctuations long before any suggestion of human influence, you should have realised by now that ice-core records do not go up to the present day. They say nothing about present day warming or lack of it.

When In did my analysis I took the ice core data up to 1860, combined it with the NOAA data up to 1979, and then used satellite data after that. That reconstruction is far better than the Hockeystick that didn’t use thermometer data until after 1900, and even when it did include thermometer data is combined them with ice core, coral and tree rings up to 1980s.
I used data that I’m pretty sure overstates warming and it still isn’t statistically significant.
Simply put, the published data, manipulated as it is, still doesn’t reach statistical significance. Simply test the data yourself.
BTW, here is the longest continual temperature measurement by thermometer. It shows no temperature increase since the 1600s.

• David A says:

Jared says, “Then add 1 degree to the end of the graph, it still puts present day below the MWP and below most of the last 10,000 years.”
================================================
Valid point, but again, in any of the deep past proxy studies many multiple decade periods of warmer or cooler times then show in the graphic not only could have happened, but likely did happen.

• MikeB says:

Yes Nick, you are right. The most recent data point for is 1855. I took ‘Before Present’ to mean before 2000AD since ‘Present Day’ it is not specified in the data. However, it seems that the paleoclimate convention is to take 1950 as present.

• co2islife says:

Although ice-core records are useful in showing past temperature fluctuations long before any suggestion of human influence, you should have realised by now that ice-core records do not go up to the present day. They say nothing about present day warming or lack of it.

1) Forget combining the data sets, the Ice Core data has a standard deviation and max and min. What are they?
2) The IPCC publishes a temperature chart going back to 1860, what is the standard deviation? If the change is tacked on to the ice core data, do you reach a peak of the Holocene?
3) If there is a direct causative correlation between CO2 and temperature, as the IPCC Models clearly are programmed to demonstrate, by what mechanism does higher CO2 cause a pause in the temperatures? By what mechanism could it ever result in cooling? CO2 peaked before ice ages, by what mechanism does CO2 cause the cooling? By what mechanism does CO2 increase to end an ice age? If the only defined mechanism by which CO2 can cause climate change is thought the GHG effect and warming, how is it affecting climate change today when we haven’t been experiencing any warming?

17. Cultural Marxism definition of logic is that it’s not independent of its content. In other words, if it supports culture Marxism its logic, if it does not it’s not logical. UNEP, UNFCCC and IPCC etc..are ideologically “Culture (science) Marxists” to promote a radical change of society. Therefore MWP and LIA are not logical if culture Marxism based science is using CO2 as a tool to make doomsday hypothesis?

18. NimrodSram says:

Too many M’s you say, – you just introduced another: Marxism, not bad, and I agree, scinetific output is steared by the ideology… Here’s another M, for Mars. I can remember a time, as a young boy in the 60’s, when the planet Mars had a fully flung North Pole with plenty of CO2-ice on it. However, nowadays, in the Modern Warm Period, we don’t see that any more. There is hardly any ice on Mars’ North pole. Why did it melt, if it wasn’t the rise in CO2 in the atmosphere of the planet??

• Joel O'Bryan says:

The Mars Phoenix lander likely had its solar panels bent and broken during the Martian Northern winter.
There is ice there.
From NASA’s website:
http://www.nasa.gov/mission_pages/phoenix/news/phx20100524.html

” “Before and after images are dramatically different,” said Michael Mellon of the University of Colorado in Boulder, a science team member for both Phoenix and HiRISE. “The lander looks smaller, and only a portion of the difference can be explained by accumulation of dust on the lander, which makes its surfaces less distinguishable from surrounding ground.”
Apparent changes in the shadows cast by the lander are consistent with predictions of how Phoenix could be damaged by harsh winter conditions. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the lander’s solar panels. Mellon calculated hundreds of pounds of ice probably coated the lander in mid-winter.”

19. Charles Nelson says:

Warmists have always detested the Medieval Warm Period. When I mention the Medieval Warm Period to a Warmist they get exactly the same look I see when I ask them to explain how a fridge works!

20. Ian Macdonald says:

An interesting related question is why castles were abandoned at the end of the Mediaeval era. History books say that was because of the invention of guns, but when you look at that theory more closely it seems unlikely since early guns were of very limited firepower and would have had a hard time breaching walls several feet thick. That, and guns firing grapeshot (which was more feasible for the guns of the day than heavy ball ammo) from the castle would have been a devastatingly effective means of self-defence, so in fact the gun’s advent would have probably been in favour of the castle owner, strategically speaking.
More likely, it was because castles were nearly impossible to heat.

• Nylo says:

With guns came cannons

• richard verney says:

I am not an expert on this but I thought that cannons preceded guns by centuries.
Further, how much damage would a primitive cannon inflict? I expect that it was less damage than that caused by an engine of war simply because of the small mass of the projectile (admittedly at far higher speed).
I have seen cannon ball damage on churches inflicted in the English civil war (circa 1650), and surprisingly the church stood up quite well, and castle walls are much thicker.

• joelobryan says:

With cannons came mortar bombs. military term today is “indirect fire.”

• Keith Willshaw says:

The short answer is they weren’t. They simply evolved. The castles of the 15th and 16th century at such as those built by Henry VIII along the south coast were designed with low thick walls and cannon platforms.
Deal Castle had as many as 145 guns in protected embrasures.
https://en.wikipedia.org/wiki/Deal_Castle
As late as the 19th century new coastal forts (castles in all but name) were built to protect Portsmouth and were manned until the end of WW2.

• richardscourtney says:

Keith Willshaw:
Yes, as you say, castle design evolved. The Maginot Line and H1tler’s Atlantic Wall were lines of castles linked by castle walls. Saddam Hussein’s bunkers were modern castles built in the late twentieth century for use in this century.
Richard

• Tim Hammond says:

As ever reductionism is wrong. There were lots of reasons why castles were abandoned, not least the Black Death centuries before that fundamentally changed European society and eventually did away with feudalism. The rise of more stable states and the rule of law followed. Gunpowder spelt the end of the armoured knight and introduced a wholly new form of warfare. Cheap, untrained peasants (compared with the lifelong training required for longbow use) could kill knights at a distance, and longer range cannons could cause havoc amongst immobile bowmen.

• DD More says:

James Burke’s Connections, linked the Swiss pike formations and not ‘Gunpowder’ to the end of the armored knights. But it did lead to bigger armies, food preservation, refrigeration (beer) and finally rockets, so it wasn’t all bad.
http://www.brainpickings.org/2010/12/23/james-burke-connections/

• Interesting question. A couple of points that no one seems to have suggested is that gun powder makes mining through a rock under the walls easier and also provides a simple way to bring down the walls. This might explain why many of the castles that did survive had moats – because the only protection against mining and blowing up the walls was a high water table.
However, I suspect a more important factor was the development of printing which empowered groups outwith the traditional hierarchy. This undermined the feudal society & church and probably did far more to bring down the walls protecting the establishment in their castles.

• I love the computer voice – it’s as if the climate models themselves are speaking!

22. The idea that equilibrium climate sensitivity is as high as 3 is just daft and it can only have been suggested by people with no practical experience of real world feedback systems.
In reality the stability of the inter-glacial threshold means that it is highly likely we current live in a period with strong negative feedbacks meaning the ECS will be less than 1C.
I know that because I am both an engineer and scientist and I know how to understand the climate by combining those disciplines. So, I watch with amusement (or anger depending how cold it is) the constant drivel being published by both alarmists and sceptics suggesting massive positive feedbacks.

• David A says:

I have not seen skeptics promoting massive positive feedbacks. Sometimes they quote them to show the evidence does not support them.

23. johann wundersamer says:

that’s the whole magic behind
the supercomputer story: a
relatively simple formula semi
wishful semi empiricism. The
only factor CO2 to explain
the world claimed to control.
Unqualifiable.
Hans

24. nobodyknows says:

Thanks to Nick Stokes for reference:
Quantifying climate forcings and feedbacks over the last millennium in CMIP5
A.R. Atwood a, E. Wu b, D.M.W. Frierson b, D.S. Battisti b, J.P. Sachs
“Attribution of global cooling during the period from 1200-1450 CE and 1400-1650 CE is similar to that for the 1600-1850 CE period. During all three periods, volcanic forcing is the dominant forcing, with a multi-model mean of 81%, 55% and 77% of the total forcing during the 1200-1450 CE, 1400-1650 CE and 1600-1850 CE periods, respectively.”
I wonder if there is some lack of imagination when volcanic forcings/ aerosols is to blame for almost all natural variation of climate. It looks like models are very fond of these forcings, and that they are blind to what is going on in the oceans (energy in and out of the oceans).

• bit chilly says:

la nina

• The only two natural forcings identified by IPCC are volcanic forcing and solar irradiance!
(Ref: Contribution from working group I, on the scientific basis, to the fifth assessment report; Chapter 8, executive summary)
It also seems that IPCC have some problems keeping track of the various plots:
“In summary, the observed recent warming hiatus, defined as the reduction in Global Mean Surface Temperatur trend during 1998–2012 as compared to the trend during 1951–2012, is attributable in roughly equal measure to a cooling contribution from internal variability and a reduced trend in external forcing (expert judgement, medium confidence). The forcing trend reduction is due primarily to a negative forcing trend from both volcanic eruptions and the downward phase of the solar cycle. However, there is low confidence in quantifying the role of forcing trend in causing the hiatus, because of uncertainty in the magnitude of the volcanic forcing trend and low confidence in the aerosol forcing trend.
(Ref: Contribution from working group I, on the scientific basis, to the fifth assessment report; BOX TS3)
Volcanic forcing looks more like an unprecise, non falsifiable, ad hoc hypothesis which purpose is to evade falsification. I guess that they alter the model parameters until they get model results that seems to fit the record they are aiming to fit.

25. Don B says:

Geoffrey Parker’s book about the (likely) coldest century of the Little Ice Age is titled, Global Crisis: war, climate change and catastrophe in the seventeenth century.
Note the word Global; the LIA wasn’t a cool spell in Europe.

26. mkelly says:

Mr. Jonas, use the maths on the top and bottom curves of the Vostok temperature vs CO2 graphs. At the top CO2 is rising while temperature is falling. At the bottom the temperature is rising while CO2 is falling. Please square that round peg. Is there an 800 year lag built into the maths?

• Mike Jonas says:

Not sure what you are getting at. The data here is from Law Dome. Maybe you are anticipating Part 3?
About the 800-year lag : No, the maths is based on the climate models, and they have no 800-year lag.

• mkelly says:

If the all the math cannot explain the decrepency between the temperature and CO2 levels in the ice core record then the math is wrong. If no lag in the math then the theory as presented is wrong.

• Mike Jonas says:

Hey, don’t blame the maths – all it is doing is applying what’s in the climate models.

27. Richard111 says:

Can someone please explain how the M-B formula is used to derive watts per square metre of warming from the CO2 gas in the atmosphere when every single CO2 molecule is radiating/absorbing over 360 cubed plus directions? Why does CO2 only see radiation from the ground when every CO2 molecule is busy all around. Maybe the molecules take it in turns. /sarc

• Joe says:

I never liked representing the effect of CO2 in terms of W/m^2, as this is an effective contribution. My preference: IR is radiated away from at the top of the atmosphere. There must a temperature delta from the surface to the top of the atmosphere to drive that much energy. the higher CO2 and water vapor concentration, the larger delta-T must be.

• higley7 says:

First, all computer models are daytime 24/7, and second, Earth’s surface in sunlight is always warmer than the atmosphere, warming the lower troposphere by conduction and convection. The upper troposphere is -17 deg C and the surface at 15 deg C.
The warmist model has it that downward IR emitted by the cold upper air is absorbed by the surface, which then is warmed. However, at the given temperatures, the IR energy levels of the surface equivalent to the IR energies given off by the cold upper air would be full and the IR would be reflected upward. No effect at all, just a slight delay in the IR being lost to space. By the way, space has no temperature as only something with mass can have a temperature. Space is not warmed by the IR passing through it.

28. Walt D. says:

This discussion about global temperatures hundreds of years ago reminds me of the story of the blind men and the elephant.
There is no way that we can construct global temperatures to 1 C, let alone 0.01 C. based on the information we can obtain. We can, however, calculate the positions of planets.
Models that purport to be able to make temperature forecasts using planetary positions at least have accurate data to work with. Even today, the Achilles heel of climate science is the lack of accurate data covering the entire surface of the Earth.
We are left with assumptions and interpolations that even average person knows are ridiculous.
The weather in London is not the same as the weather in Glasgow. What can be said about the snow in Squaw Valley, given all the snow in Boston. Yet we have a few anecdotes and proxy data in the past that are supposed to determine the temperature of the entire globe.

• Ian Macdonald says:

Other point is that the change climatologists are trying to measure over the industrial era is at least one order of magnitude less than the day/night temperature variation in most parts of the world. In most scientific disciplines it is considered poor practice to draw any conclusions from data whose mean amplitude is so far below the system noise floor.

• co2islife says:

This discussion about global temperatures hundreds of years ago reminds me of the story of the blind men and the elephant.
There is no way that we can construct global temperatures to 1 C, let alone 0.01 C. based on the information we can obtain.

There is no doubt that almost everything produced by the field of climate “science” is pure crap. What I think people should do however is hoist them by their own petards. Use their published crap against them. Use the Ice Core data and test the null hypothesis “man is not causing climate change.” Publish temperature records of the Antarctic Ice shelf and the peak of Mt Killimanjaro which show continual sub-zero temperatures, and ask the question how does ice melt in sub-zero temperature. By what mechanism does CO2 lead temperature coming out of an ice age? By what mechanism can 13µ to 18µ IR warm the oceans? The data the climate “scientists” publish simply debunks their own theory. Just look at Al Gore’s chart. 1) CO2 lags temperature and 2) all previous peaks are above today’s temperatures.
http://www.habitat21.co.uk/al-gore-graph.jpg

• “Publish temperature records of the Antarctic Ice shelf and the peak of Mt Killimanjaro which show continual sub-zero temperatures, and ask the question how does ice melt in sub-zero temperature”
..
FYI, the ice of the Antarctic ice shelf is floating on top of liquid sea water. Obviously, no matter what the temperature is above the ice, at the point of contact where the ice floats, the water temperature is high enough not to freeze.

If the ocean water underneath the ice warms just a smidgeon, the ice will melt. Ice is a very good insulator. The air above the ice can be very very cold, but the ice insulates the water underneath it.

29. Charles Tossy says:

I am not a chemist b I know that there is a temperature that CO2 disassociates. If CO2 is at this temperature, what is the concentration needed to raise the atmospheric temperature one degree?

• D.J. Hawkins says:

Whatever are you on about? Dissociation is temperature dependent; for CO2 at 1 atm, it would be about .01% at 1,000°C. How this relates to heating the general atmosphere is an explanation I anticipate with some interest.

30. errmmm….. snowing in MT right now chacha, ye hottie-hysterics.

31. Mike M. (period) says:

Mike Jonas,
Climate modellers assume that climate change is driven by changes in radiative forcing. They consider anthropogenic forcings (CO2, methane, CFC’s, aerosols, etc.) and natural forcings (solar activity, volcanoes). They do not assume that CO2 is the major forcing. They attempt to estimate the various contributions and find that the largest forcing on short time scales is large volcanic eruptions. But those are transient, so the largest forcing on long time scales, given the changes in concentration observed, is CO2.
The issue with the MWP and LIA is not whether they occurred, but whether they were global or just regional phenomena in the North Atlantic and Northern Europe.
When you don’t seem to understand what you criticize and when you rely on a cartoon from 30 years ago as “data”, you lose credibility.
When it comes to understanding the past, it seems to me that the fatal flaw of the modellers is that they focus on exogenous changes, as listed above, and discount internal changes in forcing. An example of the latter would be changes in cloudiness driven by changes in ocean circulation. The modellers think internal variation is not very important since the models don’t show much internal variation. Circular reasoning, I think.

• Mike Jonas says:

The models are compared with actual data, and then adjusted to match. It says so in the IPCC report (the key words are “constrained by observation”). Since the dominant driver of temperature in the models is CO2, that means that the models actually are assuming that all of the observed temperature change is caused by CO2.
An alternative, avoiding the assumption, would be to do the CO2 calcs, compare with actual data, and put the difference down to “unknown”. They don’t do that.
The “cartoon” you complain about appeared in an IPCC report. What I was investigating was why that “cartoon” subsequently disappeared. IOW, I’m not relying on the IPCC “cartoon”, I’m investigating it.
About the MWP : I cited multiple references that indicate the MWP was not limited to N America and Europe.

• co2islife says:

They attempt to estimate the various contributions and find that the largest forcing on short time scales is large volcanic eruptions. But those are transient, so the largest forcing on long time scales, given the changes in concentration observed, is CO2.

No amount of “forcing” is going to warm the oceans. You can take all the heat in the atmosphere and move it to the oceans and the change in temperature won’t even be measurable. The oceans have 2,000 to 4,000 the energy as the atmosphere. IR between 13µ and 18µ won’t even warm a cup of tea, let alone the oceans.

• Right, and since the heat capacity of the oceans is ~1500X that of the atmosphere, even if all of the heat in the atmosphere was somehow transferred to the oceans, there would be zero change in temperature; the ocean temp wouldn’t even begin to change until all of the heat from 1500 such atmospheres had somehow been transferred to the oceans.

• Solomon Green says:

Mike M. (period)
“Climate modellers assume that climate change is driven by changes in radiative forcing. They consider anthropogenic forcings (CO2, methane, CFC’s, aerosols, etc.) and natural forcings (solar activity, volcanoes). They do not assume that CO2 is the major forcing. They attempt to estimate the various contributions and find that the largest forcing on short time scales is large volcanic eruptions. But those are transient, so the largest forcing on long time scales, given the changes in concentration observed, is CO2.”
The last time that I counted there were more than forty different (some correlated and others possibly not) forcings. Many were relatively insignificant but others were highly significant in the short term and probably still significant in the longer term.
Put thirty-nine estimates into your model and your residual variable will show what ever you want it to show, especially if you do not allow your other parameters to vary with time, or only to vary linearly.
But I wholly commend:
“When it comes to understanding the past, it seems to me that the fatal flaw of the modellers is that they focus on exogenous changes, as listed above, and discount internal changes in forcing. An example of the latter would be changes in cloudiness driven by changes in ocean circulation. The modellers think internal variation is not very important since the models don’t show much internal variation. Circular reasoning, I think.”
I

• I would also expect this system to have a significant range of random variations. It seems like the random variation is larger than IPCC assumes. When I search for the word random in the contribution from working group I, I don’t get any particularly relevant hits. That is remarkable.
IPCC only regards volcanic eruptions and solar irradiance to be natural forcing agents.
H2O vapor and clouds are not regarded to be natural forcing agents or to exhibit significant random variation!
CO2 is regarded as the dominating forcing agent!
(Ref: Contribution from working group I, on the scientific basis, to the fifth assessment report; Chapter 8, executive summary)
The problem for IPCC is that the moment they accept more random variation, the hypothesis that: Random variation caused a significant part of the warming from 1970 something to 1997 – will stand stronger than the hypothesis that the increase in CO2 level is the main driver of global temperature.
The mission of IPPC would then soon diminish. Nobody likes to loose their mission. If you can’t convince – confuse. However, IPCC should loose their mission. IPCC does not act in accordance with a modern scientific method – the empirical method. IPCC resorts to inductivism. A few pages of reading in the works by IPCC and the works by Karl Popper should be convincing in this regard. Please enjoy a few soothing pages about the empirical method by Karl Popper:
http://strangebeautiful.com/other-texts/popper-logic-scientific-discovery.pdf

• To correct myself. IPCC call it internal variation – not random variation. Internal variability is considered by IPCC – but regarded to be quite insignificant:
“Greenhouse gases contributed a global mean surface warming likely to be in the range of 0.5°C to 1.3°C over the period 1951 to 2010, with the contributions from other anthropogenic forcings, including the cooling effect of aerosols, likely to be in the range of −0.6°C to 0.1°C. The contribution from natural forcings is likely to be in the range of −0.1°C to 0.1°C, and from natural internal variability is likely to be in the range of −0.1°C to 0.1°C. Together these assessed contributions are consistent with the observed warming of approximately 0.6°C to 0.7°C over this period. {10.3}”

32. higley7 says:

It is ingenuous in this discussion not to include night time, during which CO2 and water vapor act as “radiative gases” that convert heat energy in the air to IR radiation, which is lost to space. This is why the air cools down so very rapidly after subset and little breezes kick up so quickly on partly cloudy days.
During day time, CO2 is saturated and emitting and absorbing IR radiation as well as converting IR to heat energy and heat energy to IR. It’s a wash in full sunlight and any effects in heating the atmosphere are negligible. [Convection of air and water vapor is a huge, dominating process that is ignored by most models.] It is during night time that radiative gases actively, unopposed by solar energy input, cool the climate.
The bottom line is that no gas at any concentration in the atmosphere can detectably alter the climate. There are just too many much larger factors at play, well over fifty factors, that are purposely ignored in most computer climate models. It is no wonder that these models fail so drastically.

• co2islife says:

During day time, CO2 is saturated and emitting and absorbing IR radiation as well as converting IR to heat energy and heat energy to IR.

CO2 is inconsequential during the day. Incoming radiation can be as high as 1,000 W/M^2. IR radiation is about 1 W/M^2, and even less for 13µ to 18µ. Day time warming simply proves more visible light is reaching earth. IR has nothing to do with it. Note the scale.

• Yes I note that you used a logarithmic wavelength scale, also you are apparently unaware that the units of energy density are W.m-2.μm-1.sr-1, which gives a scaling factor of 20 between the two peaks due to wavelength. Also the unit sr is a measure of solid angle so the area subtended by the earth with the sun must be taken into account. If all those effects are taken into account the area under each curves is approximately equal, as it must be.
In any case your value for IR is a couple of orders of magnitude too low.

33. Say What? says:

The irony is that the warmists decry the clearing of the rain forests yet would kill more trees by reducing the air that trees breathe: CO2. No trees – no life – at all. No CO2 – no trees.

• John says:

I doubt you are capable of logic yet I’ll try to explain in terms you can understand.
The irony has nothing to do with logic nor scientific understanding. The irony is a tragic “herd” of brainwashed lemmings bent on self-destruction. You fail to see and don’t support logical change. You simply crow their misdirections.

• Brett Keane says:

John, bald personal slagging is not going to advance your cause.

34. Matt G says:

The biggest fail regarding estimating temperatures with CO2 increases are the failure to include pressure related equations with the doubling of CO2 calculations. Radiative forcings are used for the current values, but are based on that it is fixed between the troposphere/surface and doesn’t change with pressure. Increasing the pressure of the atmosphere has a greater impact than just a few extra atoms in the air. Whereas extra CO2 will increase the pressure slightly if enough, the tiny levels humans are adding are making no difference to the overall atmosphere pressure. No wonder the CO2 science bit is wrong.

35. Tony says:

Mike Jonas,
How does your theory taking into account that there is no ‘greenhouse effect’ under the 70% of the Earth’s surface covered by clouds? Cloud temperature is set by the lapse rate making t**4 differences with the Earth’s surface insignificant.
Long wave radiation is absorbed in the top micron or so of the oceans, where any greenhouse heating is lost by evaporation. Hence there is no greenhouse heating over another 70% of the Earth’s surface. Ocean heating is caused by direct solar radiation.

• D.J. Hawkins says:

You do realize that Mike isn’t making his own argument, but merely exploring the whole CO2 as-climate-control-knob meme using ONLY the elements as presented by the IPCC?

36. John Harmsworth says:

While I very much appreciate all the analytical work laid out here, I would like to point out what I feel is a very simple and salient fact. If it is proven that the MWP or RWP actually existed, where was the catastrophic rise in sea levels which we are assured is on the way even at present temperatures?

• David A says:

John, they were likely wrong then, and wrong now. SL has been falling since the warmest periods in this interglacial about six thousand years ago. but it is likely not steady with meter level plus flux up during warm times, down during cool times. Determining rate for the past is very difficult.
Six Thousand Years of Sea Level Change in the Southern Hemisphere
References
Baker, R.G.V. and Haworth, R.J. 2000. Smooth or oscillating late Holocene sea-level curve? Evidence from cross-regional statistical regressions of fixed biological indicators. Marine Geology 163: 353-365.
Baker, R.G.V. and Haworth, R.J. 2000. Smooth or oscillating late Holocene sea-level curve? Evidence from the palaeo-zoology of fixed biological indicators in east Australia and beyond. Marine Geology 163: 367-386.
What was done
The authors present substantial evidence that sea-level, as measured over large portions of the Southern Hemisphere, has declined significantly since approximately 6,000 years ago. But has the journey been smooth or oscillatory? In attempting to answer this question, they review data, including much of their own, obtained from a number of different places in the non-glaciated, tectonically-stable regions of the Southern Hemisphere.
What was learned
For the period from 6,000 to 600 years before present, the authors demonstrate that an oscillatory mode of sea-level decline is just as likely to have occurred, in terms of “statistical justification” based on the available data, as a smooth decline. In the words of the authors, “whether or not sea level has been subject to low-amplitude fluctuations during the late Holocene (the last ~ 6000 years) is a subject that has taken on increased importance in view of claims of possible sea-level rise associated with human-induced global warming.” If, for example, sea-level has oscillated somewhat over this period (the authors say it could have had an oscillatory amplitude of one meter or more!), it is possible the sea-level’s current rising mode may be nothing more than a small portion of a natural oscillation having nothing to do with the ongoing rise in the air’s CO2 content.

• MikeB says:

438 is the mean deuterium level

• co2islife says:

438 is the mean deuterium level

I thought something was funny about that. You are right, and my point is even more valid. The ice age starts at about -149 years. The first date is -17, but it doesn’t look like they get readings for that. By starting -149 years ago it can then be combined with the IPCC temperature chart. Thanks for pointing that out.

37. co2islife says:

I think that the black version of the NH series is pretty well matched to Hansen et al 1998. Notice that Hansen et al 1981 picked 1880 as a starting point and that this neatly truncates from view a temperature decline from 1866 to 1880 (which was in the original data version). Just a coincidence, I’m sure.

More on how Hansen manipulated that data. He deliberately cut off the cooling period just before 1880. They cherry picked the period to maximize warming.
http://climateaudit.org/2007/02/23/hansen-then-and-now/

38. Reblogged this on paullitely and commented:
Temperature records used by “climate Change” authorities begin in the mid 1800s. Their forecast models can be shown to fit there through the 1900’s. However, using the same models on the temperature series back to 1600, the models do not fit at all. No wonder the models don’t work for the 2000’s

39. Berényi Péter says:

First, the data: CO2 data for this period is from Law Dome in Antarctica

Historical CO2 mixing ratio reconstructions based on ice core data are misleading. Depending on the accumulation rate of snow at the particular site, it may take an extremely long time, even millennia for air bubbles to get separated from the atmosphere completely. In order to do that, they need high pressure, that is, sufficient depth (more than 70 m). In the meantime they are too close to the ice surface and are connected to the free atmosphere by a network of microchannels inside the ice. Diffusion through these channels washes out fast temporal fluctuations of CO2 mixing ratio, so the fossil record is a low pass filtered version of the actual one.
Also, fine particles of volcanic ash, containing olivine, get deposited to the snow surface all the time. Subsequently a chemical reaction between olivine and carbon dioxide happens in situ, forming magnesite and quartz, depleting CO2 contents of air bubbles. Therefore the ice core CO2 record is not only unnaturally flat, but its average value is lower than average CO2 mixing ratio in the free atmosphere.
Studies using fossil leaf stomata densities find higher levels and large century scale fluctuations in atmospheric CO2.

• Berényi,
What you cite is from someone who wants to give a false impression…
The Law Dome ice cores (2 at the summit, 1 somewhat downslope) have a resolution of less than 10 years for the summit cores, where the bubbles are fully closed between 72-80 m depth, where the ice is 40-46 years old. The full record goes back some 150 years. The third core has a resolution of ~20 years and goes 1,000 years back in time. The three cores have an overlap of ~20 years with the direct measurements in the atmosphere at the South Pole:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
The repeatability of CO2 levels in the ice cores are at 1.2 ppmv (1 sigma), with maximum 5 ppmv difference between ice cores taken at extremely different conditions of temperature and accumulation rate for the same average gas age.
Worst cases are Vostok (600 years resolution) and Dome C (560 years) which go back 420 and 800 kyear in time. Even these two would reflect the current increase of 110 ppmv CO2, be it with a lower amplitude.
See further:
http://courses.washington.edu/proxies/GHG.pdf
Subsequently a chemical reaction between olivine and carbon dioxide happens in situ, forming magnesite and quartz, depleting CO2 contents of air bubbles.
Pure nonsense. Most dust is desert sand and sea salt, including carbonates. Where dust is incorporated in the Antarctic ice cores, the CO2 levels are not different from layers where no/little dust is found.
Where there are frequent volcanic deposits is on the Greenland ice from nearby Icelandic volcanoes. That is highly acidic and forms extra CO2 in the ice with the carbonates from sea salt dust. Therefore Greenland ice is not reliable for CO2 measurements.
Stomata data are by definition proxies derived from land level CO2, which is highly variable and has a (variable) bias above “background” CO2 in the bulk of the atmosphere. Stomata data are calibrated against ice cores (!). If their average CO2 level over the same period as the resolution of the ice cores is different from the ice cores, then the stomata data are certainly wrong.

• Berényi Péter says:

False impression is devastating indeed, but false propositions are certainly worse.
If Law Dome ice is 40-46 years old at 72-80 m depth, and snow accumulation rate is 0.68 m/annum IE (Ice Equivalent – ice thickness at a density of 917 kg per cubic meter), as it is documented in A 2000-year annual record of snow accumulation rates for Law Dome, East Antarctica, then average density of the upper 72-80 m of ice is less than 434 kg per cubic meter, what is impossible (at a depth of 15 m it is already more than 600 kg per cubic meter).
Therefore age of ice at a depth where bubbles in it are cut off from atmospheric exchange is considerably more than 46 years, contrary to your claim.
However, even with a 40-46 years smoothing it is impossible to achieve a resolution of “less than 10 years”. The information is lost, irretrievably.

Where dust is incorporated in the Antarctic ice cores, the CO2 levels are not different from layers where no/little dust is found

That’s exactly what one would expect, provided volcanic dust layers containing olivine grains are not extremely rare. And they are not.
CO2 in enclosed air has plenty of time to find its olivine target by diffusion through microchannels, before enough pressure builds up to prevent any further movement.

40. Reblogged this on Storm Warning and commented:
Part 2 of the mathematics of CO2. It is really worthwhile getting an insight into this important area of climate science

41. Reblogged this on Climate Collections and commented:
Part 2
Executive Summary:
Conclusion
The picture of global temperature and its drivers as presented by the IPCC and the computer climate models is one in which CO2 has been the dominant factor since the start of the industrial age and other factors have had minimal impact. In order to support this picture, the IPCC has sought to portray CO2 as having been an important driver of global temperature in the past.
The idea that CO2 has been an important driver of global temperature is not supported by the evidence from the MWP and LIA (905 to 1977).
Footnote
It is important to recognise that the formulae used here represent the internal workings of the climate models. There is no “climate denial” here, because the whole series of articles is based on the premise that the climate computer models are correct, using the mid-range ECS of 3.2.

42. Mike Jonas says:

For the record : Figure 1 is not the correct version, as pointed out to me by commenter JohnMashey on hotwhopper.com (to whom thanks). I have now checked, and he was correct that “the image is not exactly FAR Fig 7.1(c)”, but it is worth noting that the two graphs are identical in terms of the data that they represent. The only differences are in the texts. So the use of the wrong graphic made absolutely no difference to any of the calculations that I presented. If you follow reference [1], it is easy to check IPCC FAR Fig 7.1(c) against my figure 1.