From the horse's mouth Paul ,ER's interacting with you is "fun", not informative but "FUN". I conclude that ER is just as much a troll as others I have just had the "pleasure" of meeting. A much cleverer one. At least ZDB is hilarious.

Can it be true that he was "invited to interact with palaeo-profesionals" (whatever they are - perhaps my age gets me into that bracket)?

Paul Dennis

I am still not too clear what your own mental model of past climates actually is. You have spent most of your time discussing uncertainties in your techniques.I have naturally followed the same theme.

Forgive me if you find my way of thinking odd. I have a jigsaw puzzle mind and any new information or ideas get played around with to see where they fit.

I was one atomic number out. It should have been boron.

Glacier Girl is the name later given to the P38 Lightning retrieved from Greenland. Alan Kendall put this comment on the 2016 sea ice thread. You probably missed it.

EM. Cannot help myself when I read so much drivel. Amount of ice decreasing since 1850. Really?

I recall some years ago seeing a fascinating TV documentary about recovering US bomber planes lost as they transit Greenland on their way to Europe during WWII. They had to be quarried out of the ice, lying as they did 10s of metres deep. The programme emphasized that the planes didn't bury themselves but that the covering ice fell as snow onto the crashed planes. I believe an ice accumulation rate of c 1m/year was mentioned.

Some decrease! History lessons for all.

Apr 2, 2016 at 3:52 PM | Unregistered CommenterAlan Kendall

He tried to imply that because snow is precipitating onto the Greenland ice sheet, it's net mass must be increasing. Logical fallacies such as this are the kind of bullshit I am talking about.

Martin A

It seems to be a rule of thumb based on observation.

I can suggest a possible reason why nights are warming faster than days. Days are warmed mostly by short wave radiation, solar insolation plus a small amount of longwave radiation from the greenhouse effect.. An increased greenhouse effect will have very small % effect on the total.

Clear nights are kept from cooling mostly by the greenhouse effect. Even a small increase in the greenhouse effect produces a large % effect reducing the cooling rate.

Winters, of course, have longer nights than Summers, and the poles have the longest winter nights of all.

The difference in warming between the poles probably has more to do with geography.

I was a bit surprised how absent the little ice age was from the CET graphs. Is it possible that computing average temperatures somehow suppresses information about how cold it really was?

Me too. That is why I have been going on about polynomials. I have been looking for a statistical test which would detect a concave curve if one were present

Of course, it is possible that the LIA was an artefact. Perhaps Paul Deennis and Alan Kendall can comment on the proxy evidence..

EM, what is your poxy proxy evidence to believe there was no LIA?

1.Mann's tree rings, and his fabricated Hockey Stick.

2.First failed attemp at an emergency Hockey Stick repair

3.All the other failed attempts at emergency Hockey Stick repair

4.Someone else is bound to find something worth repairing about the Hockey Stick, if we keep spending millions of pounds/dollars on Computer Adjustment technology

5. Burn Hockey Stick, and prove the heat given off does warm the planet

EM asserts - "Modern warming is mostly due to CO2 from fossil fuels acting as a forcing".

There is a high level of correlation between cumulative emissions of CO2 by fossil fuel combustion since about 1950 and the gradual increase in estimated average global atmospheric temperature over that period.

However there is virtually no correlation between CO2 emissions from fossil fuel combustion and the increase in estimated global average temperature rise between 1900 and 1940 which was of the same magnitude as that from 1950 to 1998. By the same token the fall in estimated global average temperatures between 1940 and 1975 occurred during a period of extremely rapid growth in CO2 emissions from fossil fuel combustion.

Thus those asserting that fossil fuel combustion is indeed the cause of modern warming are obliged to explain the absence of the other factors that must have been adequate to cause the same rate of warming in the period 1900 to 1940 in the absence of significant fossil fuel combustion related CO2 emissions in that period and sufficiently powerful to more than offset putative warming caused by that fossil fuel combustion during the period of cooling between 1940 and 1975 and also why any and all such influences must have been absent between 1975 and 1998.

Observations clearly demonstrate that EM's assertion - and indeed the statement made in the IPCC Summary for Policy Makers which contended there was 95% probability that most of the 1975 t0 1998 warming was the result of human influence (aka anthropogenic emissions of CO2 are empirically untenable.

I am reluctant to ask EM to support his contention for fear of this blog being subjected to further bouts of EM "science".

Golf Charlie

Have you not been following the discussion?

Martin A and I have been discussing what trend, if any, is shown by the CET between 1659 and the present.

The best answer we have been able to come up with is that temperatures warmed linearly by 0.48C according to CET. There is no sign of the LIA.

This raises the question of whether CET is wrong or the LIA is wrong. If CET is reliable, then there was no LIA. If there was a LIA in England then CET is useless.

Glebekinvara

Between 1880 and 1957 the CO2 content rose from 280 ppm to 315ppm. Why do you assume that this produced no temperature change, and that the effect of CO2 suddenly began in 1940?

Are you suggesting that there is a 50 year delay between the rise in CO2 and the rise in temperature?

Why not just ignore the pub bore?

This raises the question of whether CET is wrong or the LIA is wrong. If CET is reliable, then there was no LIA. If there was a LIA in England then CET is useless.

Apr 3, 2016 at 11:48 PM | Unregistered CommenterEntropic man

Did I really just read Entropic Man actually wondering whether a mean temperature was really an adequate metric of a changing climate?

It would be interesting to know on what source EM relies for the atmospheric CO2 levels of 280ppm in 1880 and 315 in 1957 - I presume it was be Keeling et al 2001. However:-

"A major issue regarding the IPCC approach to linking climate and CO2 is the assumption that prior to the industrial revolution the level of atmospheric CO2 was in an equilibrium state of about 280 ppm, around which little or no variation occurred. This presumption of constancy and equilibrium is based upon a critical review of the older literature on atmospheric CO2 content by Callendar and Keeling. Between 1800 and 1961, more than 380 technical papers that were published on air gas analysis contained data on atmospheric CO2 concentrations. Callendar,( 1940) Keeling(1960) and the IPCC ( 1-5AR) did not provide a thorough evaluation of these papers and the standard chemical methods that they deployed. Rather, they discredited these techniques and data, and rejected most as faulty or highly inaccurate Though they acknowledge the concept of an ‘unpolluted background level’ for CO2, these authors only examined about 10% of the available literature, asserting from that that only 1% of all previous data could be viewed as accurate.

"The data accepted by Callendar and Keeling were [those that were] sufficiently low to be consistent with the greenhouse hypothesis of climate change controlled by rising CO2 emissions from fossil fuel burning. Callendar rejected nearly all data before 1870 because of “relatively crude instrumentation” and reported only twelve suitable data sets in 20th century as known to him out of 99 made available by Stepanova 1952. The intent of these authors was to identify CO2 determinations that were made using pure unpolluted air, in order to assess the true background level of CO2. Callendar set out the criteria that he used to judge whether older determinations were “allowable” in his 1958 paper which presents only data that fell within 10% of a longer yearly average estimated for the region, and also rejected all measurements, however accurate, that were “measurements intended for special purposes, such as biological, soil air, atmospheric pollution”. ( Beck 2007)

Beck accepted that a proportion of the pre 1957 northern hemisphere Atmospheric CO2 concentration measurements were unreliable for a variety of reasons but established a large number dating back to the early 19th century that were accurate to within 1-3%. Beck used these measurements to reconstruct the history of atmospheric CO2 concentration from 1810 to 1960.

This shows CO2 concentration of 410 ppm in 1810 rising to 450 ppm in 1823, falling back to 345ppm in 1849 then rising to 370ppm in 1858. It then fell to 280 ppm in 1880 before rising slightly to 300 ppm in 1930,. It then rose to 415 ppm in 1944 before falling back to 315 ppm in 1960 – after which date all measurements are made by Keeling’s IR Spectroscopic method and reported as the Mauna Loa series.

The convenient correspondence of CO2 in Antarctic ice cores of 280ppm in 1880 and 315 ppm in 1957 was used by Keeling to support his assertion that 280ppm was the true “ pre industrial “ level notwithstanding that he hand picked chemical measurements in that year because they corresponded with the measurement of 280 ppm in ice core. This is despite the fact that no study had then ( nor has yet) demonstrated that the content of greenhouse trace gases in old ice, or even in the interstitial air from recent snow is representative of the atmospheric composition.

Keeling then spliced the Mauna Loa value of 315 ppm in 1957 on to the ice core time series of CO2 measurements – thereby providing an example of malpractice to be followed by Mann in creating the infamous “Hockey Stick”.

The assertion of a stable CO2 level of 280 ppm is the true "pre industrial" level is required to be valid by all proponents of the AGW hypothesis. Evidence to the contrary has been suppressed or is ridiculed as it undermines not only the basis of the AGW hypothesis but because it also discredits the proposition that CO2 in inclusions in ice cores are representative of atmospheric concentrations - even though it is admitted that there is a discrepancy of 80 to as much as 2800 years between corresponding values in atmosphere and ice.

EM, wrong again!

I have been following this discussion, and your use of rhetoric to squeeze in some more false/dubious assumptions.

Please carry on!

Monckton notwithstanding, you cannot really use CET for trend calculation before the 1770s.

Before then, Manley hopped over the channel to Utrecht to infill missing values, lovely town but not actually in Central England, and most readings were taken indoors.

The series went daily in 1772. From 1722 onwards Manley optimistically states a precision of 0.1C, before that the monthly means are given to the nearest one or 1/2 degree C , so the trend during the early years would be completely drowned in the noise.

Beck is a bad joke. Fluctuations of 150ppm / decade with no trace in the biological record? Taken in Paris , Dieppe, Copenhagen?

Now wonder he had to turn to Energy & Environment.

Michael hart

Did I really just read Entropic Man actually wondering whether a mean temperature was really an adequate metric of a changing climate?

Yes, you did.☺

Mind you, Phil Clarke has helped explain our problems. LIA beats CET, at least before 1770.

EM, but if one temperature record differs from another, aren't you supposed to argue that the satellites carrying the leather buckets had been sampling from different heights due to the stretchiness of the hemp derived rope or something?

Phil Clarke, where did you suddenly find such a mine of historical information about discrediting historical information?

I thought that was Mann's technique/mistake. Is it being repeated by others to prove Mann's integrity?

I read the references.

• Parker, D.E., T.P. Legg, and C.K. Folland. 1992. A new daily Central England Temperature Series, 1772-1991. Int. J. Clim., Vol 12, pp 317-342
• Manley,G. 1953. The mean temperature of Central England, 1698 to 1952. Q.J.R. Meteorol. Soc., Vol 79, pp 242-261.
• Manley,G. 1974. Central England Temperatures: monthly means 1659 to 1973. Q.J.R. Meteorol. Soc., Vol 100, pp 389-405.
• Parker, D.E. and Horton, E.B. 2005. Uncertainties in the Central England Temperature series since 1878 and some changes to the maximum and minimum series.International J.Climatology, Vol 25, pp 1173-1188. 

Beck, well E&E is a comedy journal, his numbers are wildly wrong because the fluxes required are physically impossible, because the measurements were taken in urban areas, or downwind of urban areas, with equipment that was hard to calibrate and there is no confirming trace of these concentrations in biogenic indicators.

You know - there's a reason modern measurements are taken in the middle of oceans or on the coast, and above the inversion layer.

http://www.realclimate.org/index.php/archives/2007/05/beck-to-the-future/
http://rabett.blogspot.co.uk/2006/10/amateur-night.html

Phil Clarke's objections to Beck and Energy and Environment above look suspiciously like ad hominem arguments.

Be that as it may - Quite apart from chemical measurements of CO2 in air- ( where in a well mixed atmosphere it should not matter whether they were made in Paris , Dieppe and Copenhagen and not by Beck but by a large number of independent analysts over a long period of time) - there are plenty of uncertainties about the representativeness of measurements of CO2 in air bubbles in ice cores taken at different depths and from firn and ice of different depositional ages.

In samples of air from firn and ice at Summit, Greenland, deposited during the past ~200 years, the CO2 concentration ranged from 243 ppmv to 641 ppmv. Such a wide range suggests artifacts caused by sampling, or natural processes in the ice sheet, rather than the variations of CO2 concentration in the atmosphere. Until 1985, the published CO2 readings from air bubbles in pre-industrial ice ranged from 160 to about 700 ppmv, and occasionally even up to 2,450 ppmv. Neftel, et al. reported in 1982 median CO2 concentrations in the pre-industrial ice core from Byrd, Antarctica, of about 330 and 415 ppmv, with maximum value reaching 500 ppmv.

In 1988, in the second publication on the same core, Neftel et al. did not show these high readings; the highest concentration reported was 290 ppmv. Etheridge, et al. claimed that their ice core results show a pre-industrial N2O concentration of 285 ppbv. This value was calculated after rejection of 44 percent of [their own] measurements. From the remaining analyses, the high readings from16th and 17th century ice (328.3 and 329.8 ppbv), were higher than those in the 20th century samples. A assumption [ was made ] that the air in bubbles in ice is 90 to 200 years younger than the ice in which the bubbles are entrapped, and it was offered a time when the concentrations of greenhouse gases in air bubbles from ice deposited in the 18th and 19th century were found to be similar to those of the present atmosphere. No experimental evidence was offered in support of this assumption.

Craig et al. offered the argument that this speculation must be correct, because the ice core data for a greenhouse gas with the ages corrected in this way “lead rather precisely into the recent atmospheric measurements” - which appears to be a circular argument.

Later, the assumption for the difference between the age of the air and the age of the ice was theoretically, but not experimentally, elaborated, with estimations of this difference for various polar sites ranging between 90 and 2,800 years. These estimations were based on the age of the firn/ice transition. It was supposed that in the Greenland and Antarctic sites, where the mean annual temperature is 22 ° C or less, the whole column of firn was devoid of ice layers that were impermeable to atmospheric air. Further, it was suggested that air can freely penetrate into the ice sheet, down to the firn/ice transition at about 40 to 120 m depth, where final occlusion of the firn pores occurs

An attempt was made to prove the validity of the above assertion in an experiment carried out in a borehole at Summit, Greenland. At this site, the authors estimated the air/ice age difference as 210 years. As was indicated CO2 concentration measured in 214-year-old firn ranged from 242.3 to 435.7 ppmv; and from 50-year-old firn, it ranged from 347 to 641.4 ppmv. Such concentrations do not likely represent the composition of atmospheric air, but rather the fractionation processes in the ice sheets, and experimental artifacts.

Dogmatic assertions are made that the atmospheric concentration of CO2 in the late 19thcentury was 280 ppmv based on the estimates obtained from ice cores. But there is considerable uncertainty surrounding the absolute validity of the results obtained due to metamorphic changes in the structure of the ice with increasing age and depth, and of the consequences of stress relief and phase changes which occur when the ice core is extracted and relieved from "lithostatic" load.

Regrettably it has not yet proven possible to independently validate the correspondence of CO2 values from cores of ice over 125 years old with the undisputed results of measurements made of CO2 in air at the same time.

The consequence of the assumption that the air in bubbles is younger than the ice in which the bubbles are found, is widely accepted as a “proof” that the level of CO2 in the atmosphere has been increased by man’s activities.

It looks to me as if Dr Best did see a clear dip in yearly-averaged temperatures curing the 17thc.

http://clivebest.com/blog/?p=7015

Martin A

The only warming of the Earth is by radiation arriving directly from the Sun. Let's not have any 'back radiation produces warming' nonsense.

Back radiation is just energy that failed to make it back out to space at its first (or second or umpteenth) attempt.

And the effect is a reduction in cooling rate. I'm quite happy with that.

If you are being pedantic today, how about this. "The greenhouse effect slows the rate of heat loss. Therefore daytime temperatures are slightly less cold than they would be without it."

Note that I explicitly phrased the effect on nighttime temperatures in terms of reduced cooling.

Would not that explanation depend on the assumption that all the warming since 1659 was due to the greenhouse effect?

That seems a reasonable hypothesis. If you look at the forcing budget, CO2 is by far the largest positive forcings. Second is CH4, then black carbon. The rest are small positive, neutral or negative.

If you have something else with a forcing powerful to replace CO2, now's the time to show your numbers.

The graph is interesting.The quadratic line hints at the pattern the LIA and the subsequent warming would produce. Golf Charlie will be pleased.

Did you read Phil Clarke's comment on the poor reliability of CET before 1770? Perhaps this is when you should start your next graph?