Guest essay by Tony Brown
Some readers might recall my recent article ‘The Long Slow Thaw?’
In this I reconstructed Central England temperature to 1538 from its current instrumental date of 1659.
I was surprised by two notable periods of warmth around 1630 and 1530. I am indebted amongst other material, to Phil Jones excellent book ‘Climate since 1500 AD’ plus such books as Le Roy Laduries’ Times of feast times of famine’ which confirm that these were indeed warm periods.
The graph below is from my article but to it has been added the official co2 levels. CET is seen by many scientists as a reasonable but by no means perfect proxy for Northern Hemisphere and Global temperatures.
Please note that the graphing package somewhat inflates the warmth in the decade around 1540, although my recent research- which will extend CET to 1498-demonstrates that the period 1500 to 1540 does indeed appear to be around as warm as the warm period in the recent CET period ending around the year 2000, characterised by the distinct hump.
Also from a graphing viewpoint it is debatable as to where the CO2 line should be placed. I chose to place it around the black trend line as the CO2 and temperature trend line probably needs to start together at the same place. This also provides clarity and context to the graphic although others might feel the CO2 line should be placed elsewhere.
However these are all nuances and the point I want to put over is that temperature is highly variable throughout the CET record -which is at variance to Dr Mann’s (global) work and the assertions of the Met office. This is despite a constant level of co2 until around 1900. The temperature decline since 2000 as the CO2 line rises ever further is especially intriguing.
Does it demonstrate that once you get to around the 300ppm level that the law of diminishing returns sets in as the logarithmic curve of CO2 versus temperatures takes effect? Does it illustrate nothing and the current downward CET slope is merely a blip that will increase sharply again as more CO2 is added?
The apparent effects of adding additional CO2 was clearly shown in an article by David Archibald several years ago,
http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/
I merely present my research and findings for comment. An apparent decline perhaps as the logarithmic effect ceases to have any real world meaning? Or merely a hiatus in the ever upwards rise of temperatures since the start of the record in 1659 which may or may not be affected by CO2 and radiative physics?
.
Last time I looked, one of the CET temperature sensors, was outside the engine run-up bays, in the middle of Manchester International Airport (one of the busiest in the UK), where all the aircraft taxy past, and where engines are run for extended periods to test them. The run-up bays have a series of baffles behind them, to deflect the noise (and the heat) back towards the airfield. Is it still there?
Another CET sensor was 50 m north of the runway at Blackpool airport, which is a regional airport but does handle jets in the summer. Is that still there too?
Has anyone looked to see if the CET is now in synch with the flight departures schedule from Blackpool and Manchester??
.
ralfellis
I made the point about the CET record likely being affected by modern urbanisation in my reply to David Hoffer early on in the thread.
I asked the Met office about the degree of uhi they factor in and it is smaller than I would have thought. I am inclined to think the modern hump in CET obvious in my graph has an element of exaggeration to it but working that out on a scientific basis is problematic.
tonyb
Good work Tony, no computer models, just hard work extracting data from contemporary records.
The CET is a good proxy for both the N. Hemisphere’s and global temperature trends
http://www.vukcevic.talktalk.net/CGNh.htm
with proviso that the CET has greater year to year variability, but longer trends are absolutely identical. I see no reason why this can not be extrapolated back to before 1880s.
Vuk
Cet appears to be a reasonable proxy and has many benefits over other less certain proxies such as tree rings. I see great value in being able to reconstruct CET as far back as is possible whilst still retaining a reasonable degree of accuracy. Your graph is most interesting.
tonyb
TonyB
‘CET is seen by many scientists as a reasonable but by no means perfect proxy for Northern Hemisphere and Global temperatures.’
It is claimed that CET shows links to the AMO and NAO for seasonal weather in Europe but it does not reconcile with the data from the Central Europe record. Do you have a comment on this? Can it be that these different anomalies reflect differences in precipitation, hence convective cooling as shown by Clive Best and in the following paper on wheat yields that are sensitive to soil moisture?
http://research.eeescience.utoledo.edu/lees/papers_PDF/Atkinson_2005_AFM.pdf
And to widen that query, are differences in precipitation and consequent soil moisture the reason for the 30 % of cooling stations found by BEST in the GHCN record and why cooling and warming stations in SE USA are intermixed in an area subject to cyclical changes in precipitation due to ENSO switching from El Nino to La Nina. In fact is the global temperature series not confounded with precipitation effects that vary from year to year?
The Central European temperature is an average of records from Prague, Vienna, Hohenpeissenberg, Kremsmünster, Paris, and Munich.
http://joannenova.com.au/2013/05/fourier-analysis-reveals-six-natural-cycles-no-man-made-effect-predicts-cooling/
peter azlac says: May 9, 2013 at 1:35 am
It is claimed that CET shows links to the AMO and NAO for seasonal weather in Europe but it does not reconcile with the data from the Central Europe record.
I always look for controversial elements in data. As far as the CEuropeT and CEnglantT here is my observation
http://www.vukcevic.talktalk.net/NVp.htm
so they the two CETs could ‘reconcile’.
Nick Stokes says: May 8, 2013 at 7:05 pm
Tonyb,
“Have you any comments as to the considerable variability of temperature over the last few hundred years at a constant level of co2, the recent decade long drop in temperatures we can observe , or indeed the centuries long uptick we can note,”
Yes. No-one said co2 is the only determinant of temperature, or that it caused past fluctuations.
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Are you sure?
Vuk
Thanks. I thought you had done some work on the Central Europe record.
I think there is reasonable but not perfect correlation. It is useful to remember Lambs point about historic temperatures in as much ‘we can understand the tendancy but not the precision.’
We can not know to tenths of a degree the prevailing temperature over a wide area but we can certainly see the general direction of travel. Your graphs are most useful in illustrating this
tonyb
mpainter says: May 9, 2013 at 1:49 am
“Are you sure?”
Well, OK, “that it caused past fluctuations” could be better phrased. CO2 may have given a positive feedback boost to Ice Age termination, for example. CO2 ppm changes somewhat with sea temp. And maybe it did more many millions of years ago, when concentrations were much higher. But it hasn’t recently been a driver of change, because nothing has been driving it. Until now.
Nick
So you appear to be arguing that co2 hasnt been a major driver in the past but will be so in the future?
I can respect that position, but do wish that so many scientists who push the notion of lack of variability in the past would argue the case for radiative physics instead of coming up with all sorts of studies that distort climatic history.
I also wish they would be more circumspect with the data they use. Sea ice data prior to the satellite era and such things as historic SST’s and sea level data are not robust enough for them to be used in supposedly scientific studies that influence national policy.
tonyb
I would like to know what proxies were used to go back to 1530 since thermometers were not around until 1650’s and no thermometer with an accurate scale until 1680’s. It was not until the mid 1700’s that a standard scale was decided and even then two were in use.
Also where are the atmospheric CO2 readings from and what proxies were used to calculate these.
some have attributed the PETM to a CO2 influx from …somewhere. There are other examples in the scientific lit. of such flimsy attributions to CO2.
Over time the swings from hot to cold are reducing and the warmer periods are increasing but there is not a large increase in the maximum temperatures. It’s just warm for longer. The climate is becoming more friendly. It’s getting less cold and not a lot hotter.
I can remember when I was young we often used to get summers with really uncomfortable hot periods when it was difficult to breath and get comfortable. These periods would end in violent thunderstorms. I can’t remember any thing like it in recent years.
Nick Stokes says: May 9, 2013 at 2:09 am
…………… CO2 may have given a positive feedback boost to Ice Age termination, for example. CO2 ppm changes somewhat with sea temp. And maybe it did more many millions of years ago, when concentrations were much higher. But it hasn’t recently been a driver of change, because nothing has been driving it. Until now.
Time is rapidly approaching when the climate scientists may have to get of their magic CO2 flying carpet and come down to the ground, or even better dive into depths of North Atlantic and look at Mid Atlantic Ridge.
http://www.vukcevic.talktalk.net/NVa.htm
The far north end of the MAR moves the ocean currents around Iceland, affecting atmospheric pressure in the area (summers to the north, winters to the south ),
http://www.vukcevic.talktalk.net/CB.htm
resulting in shifts of the polar jet stream, changing the weather/climate of the whole of N. Hemisphere Since most of the records are from NH, global data will follow suit.
http://www.vukcevic.talktalk.net/CGNh.htm
About climate change talk to geologists not statisticians and computer modellers.
John Marshall
Please read my article ‘The long slow thaw?’ linked to above, as many of your questions will be answered. In addition there is a link from within the article which contains methodology, sources and references-it is here;
http://curryja.files.wordpress.com/2011/12/long-slow-thaw-supplementary-information.pdf
The second part of your question I have more difficulty with. I have used ‘official’ co2 figures so that part can not be contested by people such as Nick Stokes. There is another school of thought-generally riduculed- who suspect that co2 concentrations was more variable in the past and rose to a similar level to today as recently as the 1940’s. Generally the historic records at 280ppm are said to be derived from ice cores. I wrote about the subject here.
http://noconsensus.wordpress.com/2010/03/06/historic-variations-in-co2-measurements/
As I said on the thread I remain to be convinced as to whether the modern or historic co2 record are the more accurate. If it were more variable than it appears it might explain the comsiderable historic temperature variation.
Whenever this topic comes up on WUWT there is always a heated debate!
tonyb
Tony Brown, you mentioned the first two peaks of temperature at 1530 and 1630, but this happenned about every hundred years right through. The peak in 1830 was the least. Also there was another rise at about the 80 year mark in each century with the one in the 1980 mark being outstanding. Are these significant, and do they correspond with planetary movements. If the sun affects our tides as it does, can an alignment of the planets have a tidal effect on the sun.
vukcevic says:
May 9, 2013 at 1:44 am
‘I always look for controversial elements in data. As far as the CEuropeT and CEnglantT here is my observation
http://www.vukcevic.talktalk.net/NVp.htm
so they the two CETs could ‘reconcile’.
As always, your graphics are interesting and informative and do show a parallel trend between CET and CEuropeT records for most of the time. But the claim that it is due to conversions from oF to oC is negated, to my mind, by the fact that the two records agree in magnitude around 1810 to 1860 but then markedly diverge only to come together around 1976. It is the differences in the magnitude of the anomalies that I am interested in and this could well be linked to precipitation and surface water capacity.
Frank Lasner with his Ruti project has demonstrated that there are three major types of climate zones – coastal, inland plain and inland at altitude with the first and last most affected by SST: he shows these effects for the CET area. CET mixes these zones and so averages out the anomalies – the two stations at Ringway and Squires Gate are both in a zone with a high level of precipitation: I can say that from experience as a grew up mid way between them! They are also both at airports and subject to high changes in UHI. Malvern, in a hill area, has now been substituted by Pershore which is on a plain, as is Rothamsted These differences can be seen in the Meteo records:
http://www.metoffice.gov.uk/climate/uk/averages/regmapavge.html
Except for Malvern they have also been subject to a UHI effect as shown in the UK heat maps:
http://tallbloke.wordpress.com/2012/09/04/wmo03318-blackpool-squires-gate/#more-7845
And if we compare the data from the latest CET stations, we see that a large part of the uptick shown in the CET record comes from Tmin values at Rothamsted that is in a dry area away from the coast and subject to high changes in UHI.
http://www.anenglishmanscastle.com/archives/004438.html
These comments are not intended to diminish in any way the work carried out by TonyB, which I find to be very informative and useful. Rather more of a stimulus to him and others to break the CET and other records down into the climate zones from which they are made up and to evaluate the changes in these zones with local data on temperature, precipitation, surface TSI and paleo data which I believe will lead to a greater understanding of the drivers behind climate change than can be obtained by using averaged global or regional data.
I should add that I consider that climate science will only make real progress when it abandons land surface temperatures and concentrates on atmospheric and ocean heat flux, as proposed by Pielke Sr., and solar affects.
Peter W Whittaker
Yes, those hundred year and 80 year peaks are interesting arent they? Generally speaking the Met office promote their version of CET (with daily rather than monthy records) to 1772
http://www.metoffice.gov.uk/hadobs/hadcet/
Consequently the warm points in the 1730′ 1630’s and 1530’s (the last 2 being my reconstruction) don’t stand out as there is limited data for researchers if the 1772 record is used.
I have heard all sorts of theories but I am not aware of any detailed professional (i.e funded) objective research into the reasons behind this apparent periodicity in CET.
tonyb
Peter
I am no believer in the notion of a ‘global’ temperature and have great sympathy with the comment by Marcel Leroux;
“They well know that the world has many climates.’
I suspect that CET is representative in general terms of some of these climates and at times most of them as worldwide circustamces converge, for example during the MWP when most (but not all of the word) probably warmed. So in that respect CET is about as close as we can get to a ‘global’ figure whilst accepting that such a thing is an academic premise and whose pursuit blinds us to the myriad reasons for our ever changing climate that occur on a more ‘local’ basis.
For example, we know that throughout the spell of rising ‘global’ temperatures there were many places that were actually cooling. I wrote about it here with Verity Jones.
http://diggingintheclay.wordpress.com/2010/09/01/in-search-of-cooling-trends/
So yes, breaking down the data into climate zones to a standard that would be accepted by the climate community is something on my agenda (as is determining the amount of UHI in the recent CET record)
Unfortunately these are big tasks beyond the resources of such as myself who are still waiting for that promised cheque from Big Oil to drop through the letter box.
tonyb
Just in from Railtrack, it is the wrong kind of CO2
Nick Stokes says:
May 9, 2013 at 2:09 am
But it (C02) hasn’t recently been a driver of change, because nothing has been driving it. Until now.
That’s what the climatists claim, with very little evidence to support it. Climate change before was natural, and now it isn’t. Pathetic. It’s a Belief, nothing more.
Nick Stokes;
But now we’ve been putting fossil C directly in the air – about 350 Gtons so far. That’s a new situation. Should we stop?
>>>>>>>>>>>>>>>>>>>
Big numbers sound scary. New situation sounds scary. There’s 6 billion people on the planet. That’s a new situation. Should we stop making people? They are growing and eating more food than ever before. Gigatons and gigatons of biosphere being digested every day. Unprecedented!
Once again you have avoided the question, which is to produce any evidence of ill effects. You just shout words in a manner to make them sound ominous. That’s fear mongering.
Say, what do you see in CET ?
U C lots of temperature variation
and precious little CO2 correlation.
Nick Stokes says: May 9, 2013 at 2:09 am
But it hasn’t recently been a driver of change, because nothing has been driving it. Until now.
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Chronic alarmism. Driver of change, you say? What change, pray tell?
The original entry and most of the comments are undermined by the facts and known science. Only eco-geek, Ian W and Geoff S seem to understand that CO2 levels are highly variable. Geoff imagines that CO2 concentrations would be higher in industrialized areas. However, the reality is that the human effect on CO2 is negligible. Some facts:
1. A study from Germany found that there is no CO2 dome over cities, even highly industrialized cities.
2. CO2 levels varies greatly (geographic, local fauna, wind conditions).
3. Plants are fed when a lack of wind allows CO2 to settle, greatly increasing CO2 levels at ground level.
4. CO2 is not a static quantity, but is in constant flux, since it is part of 2 main carbon cycles.
5. Like the water cycle, CO2 rises from and then “rains” down into the oceans again, according to Henry’s law.
6. Hot equatorial waters expel CO2 while cold water absorbs it. Segalstad has determined that the time period is only 5 years.
7. Mauna Loa is downwind and just north of the equator. Like any single point of data, it’s meaningless.
8. The idea of a “global CO2 level” is just as meaningless as a “global water vapor” level or a “global temperature”.
9. Segalstad has determined conclusively that man’s effect on the CO2 flux is on the order of .2%.
10. CO2 is soluble in water, so ice cores will always show a CO2 hockey stick, which only confirms Henry’s Law.
11. CO2 is not reflective, so the “greenhouse” analogy is invalid. The missing 33 degrees can be easily explained.
12. CO2 micro effects (so called “radiative physics”) cannot contradict macro thermodynamics.
13. Thermodynamics is driven by delta T, mass and energy storage of the various components.
14. The mass of Earth’s crust dwarfs the mass of the oceans, which dwarfs the mass of the atmosphere.
15. Thus, the energy flow is: Sun heats crust and oceans, and the temperature of the atmosphere is dependent on them.
16. The mass of the atmosphere is negligible, so one could not heat the ocean/crust by heating a small fraction of the atmosphere.
17. Heat is transferred away from earth by radiation from the top of the thermosphere. There is almost no CO2 above it.
18. Heat is transferred from crust/oceans to the top of thermosphere by various methods, but radiation is negligible.
19. Some other heat transfer mechanisms are convection, conduction, evaporation, precipitation, physical transport.
20. The atmospheric temperature is largely determined by the air pressure: PV = nRT.
21. The temperature on Venus (96% CO2) is similar to that of earth, at the same atmospheric pressure.
>> But an increase does cause warming,
No, it doesn’t.
>> and we’re digging up huge quantities of carbon and putting it in the atmosphere.
Actually, .2% says that man’s impact is teeny tiny.
>> That’s unprecedented.
What’s unprecedented is man’s conceit and his ability to believe so strongly in a myth:
Picture an arena with 20,000 people in attendance, where each person represents a molecule. The change in CO2 reported from ML is equivalent to one extra person entering the arena.
It’s truly unprecedented that people’s idea of science is to believe without evidence that this extremely negligible change could magically override many scientific laws, including Henry’s law and the laws of thermodynamics.