By Steve Goddard
My friend Tamino says that “the modern global warming era starts in 1975.”
He goes on : “It’s an estimate of the time at which the trend in global temperature took its modern value.”
As you can see in Phil Jones’ HadCRUT graph above, the 25 year period from about 1975 to 2000 did warm about half a degree C.
You can also see that the 30 year period from 1910 to 1940 similarly warmed about half a degree C. At that time, atmospheric CO2 averaged about 305 ppm, well below Dr. Hansen’s suggested “safe level” of 350 ppm. See the graph below for that period:
Here’s an annotated HadCRUT graph to help you see the relevant periods and the changes of temperature versus changes in global CO2 concentration during the same period:
The video below superimposes the 1975 warming (blue line) on the 1910 warming (black line.) Note the similarity in slope, duration and patterns. It would be difficult to explain the 1910 warming as being due to CO2, because CO2 was barely above pre-industrial levels and rose only 10 ppm during that period.
Given the similarity between the 1975 warming and the 1910 warming, it is irrational to blame the 1975 warming entirely on CO2. The practice of good science tells us to look for a hypothesis which can explain both similar warming periods.
If there is an influence of CO2 in the recent warming, it appears small. And the warming stopped ten years ago, as shown in the HadCRUT graph, despite rapid increases in CO2.
Or perhaps one might conclude that climate sensitivity has decreased as CO2 levels have risen. In 1910, with CO2 at 300 ppm, it only took ten additional ppm to raise temperatures by 0.5°C. By contrast, in 1975 it took about fifty ppm more to produce the same 0.5°C warming by the year 2000.
There were also periods of time with rising CO2, and little or no rise in temperature. From 1940 to 1980, there was no net warming while CO2 rose by 30 ppm. Since 1998, there has been no warming – as CO2 levels have risen 30 ppm.
I feel a chill of La Niña coming on.
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Okay Goddard, Stop saying 1998 was the warming globally. We both know that the analysis by the European Centre for Medium-Range Weather Forecasts (ECMWF) found warming has been higher than that shown by HadCRUT. So did you choose the dataset which fit your answer Goddard? Why didn’t you put up GISS or NOAA?
http://www.metoffice.gov.uk/corporate/pressoffice/2009/pr20091218b.html
Also lets consider some things. There was a rapidly increasing solar activity during the early century warming yet there is not now? Also remember that volcanic activity was lower during the early century but volcanic activity has been relatively high even into the 21st century. Lets also consider some things. When Mosher and them put together all their global temperature analyses, the majority of them found 1998 to not be the warmest:
http://wattsupwiththat.com/2010/07/13/calculating-global-temperature/
You are also completely ignoring the inertia and time-lag of CO2 induced warming.
A proposal: Heat output from the sun has been increasing since around 1700 to which we have added significantly and increasingly in the latter third or so, by our production of energy. Both increases have lead to a general warming of the planet (the Maunder Minimum was not local to Europe) and the conditions we enjoy today.
From figures for worldwide consumption of all energy sources other than kinetic & solar, 14 Terajoules per second are added to the heat input of our planet, at or around surface level: all energy produced eventually and quickly decays to heat.
This man-made production of energy equates to 0.03 W/m2 for every m2 of surface or a 0.03% increase over the input of the sun. A 1% increase in solar irradiative change produces a climate forcing of 0.24 W/m2. From that we can calculate that a forcing of 0.03 W/m2 is a solar irradiative increase equivalent of 0.125%.
From the Maunder Minimum to now, a 0.25% increase in solar output has occurred. The Maunder Minimum coincided with the Little Ice Age and since which time temperatures have been generally meandering upwards with a coincident 0.25% increase in solar output. Mankind’s current addition to forcing of 0.125% is half of that difference and has been added in annual increasing amounts, mostly during the latter third of the period since 1715. Inaccurate temperature analysis & unproven theories on atmospheric CO2 can be set aside.
Anyways, tamino already caught you cherry picking and i’m sure he will be dealing with this soon enough. Too bad your loyal viewers didn’t see you get completely proven wrong at taminos twice now in the last two weeks… He proved you wrong and your response was something about the hockey stick being wrong. Nothing to do with the topic of conversation but hey, you had to say something right?
Michael Hauber says: “Giss model E forcings suggest that the warming between 1910 and 1940 was caused by roughly equal parts of increase in solar activity, increase in Co2, and reduction in aerosols (i.e. volcanos early in the period, and an increase to no volcanos late in the period).”
Model forcings are not data and thus can’t ‘suggest’ anything. They can only assume.
@Carrick says: August 22, 2010 at 10:44 pm
“Other forcings play a role besides CO2, and prior to 1980 it’s generally agreed in the climate community that sulfates balanced CO2.”
Hmmmm.
I think you’ll find that it is “generally agreed in the climate community” that they need to dream up much better excuses and “adjustments”.
Otherwise the whole BigSnakeOil cAGW scam will go down the drain and they’ll have to start looking for another job.
I think my position that the trends are not unexplainable by weather variations is still sound. Averaging is supposed to remove the variation. I remain unconvinced. I think selective averaging may remove some variations. I think that averaging techniques are not representative of the energy in the system. If you have a 24 hour period, and 23 of 24 hours are 30, and one is 50 you have an average of 40 the way that average is currently derived. This is a problem because the average should have been 30.833_.
Not to mention that the temperatures derived before the modern era may not have registered temperatures caught by today’s thermometers because of the ability of today’s thermos to catch temperatures more quickly than older temperatures. The highs may have been higher, the lows may have been lower. That data, imho, can’t be compared.
David Gould 9:55 pm,
“…..If the argument was that CO2 was the only driver of global temperature, the ups, downs and flatlines would show that argument to be false. But, given that that is not the argument …”
The behavior of the hopelessly credulous catastrophic AGW zealots suggests to me that they do indeed believe that CO2 is the only driver of, not only the global temperature, but the global climate, droughts, hurricanes, floods, disease, earthquakes, tsunamis…..
http://www.numberwatch.co.uk/warmlist.htm
…..and who can blame them.
The ‘The Congregation for the Doctrine of the Faith’, the IPCC, has unequivocally stated: Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (over 90%) due to the observed increase in anthropogenic (human) greenhouse gas concentrations.
If over 50% of the alleged warming since 1950 is due to human GHGs, it doesn’t leave room for much else.
http://upload.wikimedia.org/wikipedia/commons/b/bb/Radiative-forcings.svg
I performed a similar comparison of the two warming periods in an earlier post. I used global SST anomalies (but excluded the comparison of CO2 data). The linear trends of the two periods are basically identical. Here’s a graph of the early period:
http://s5.tinypic.com/119qzk6.jpg
And the later period:
http://s5.tinypic.com/2vuk978.jpg
I then removed the impacts of the AMO, solar, and volcanic aerosols and ran the trends again. Here’s a link to the post:
http://bobtisdale.blogspot.com/2009/03/has-global-warming-accelerated.html
Dagfinn says:
August 22, 2010 at 10:58 pm
It’s all in the language. IPCC remarks that discrepancies between satellite data & surface based observations have largely been resolved. This is such wishy-washy guff & Meta speak meaning that they cannot resolve such discrepancies (admitting there are more than one such difference at least) so they just say they have, easy peasy!
Robert: August 23, 2010 at 12:16 am
You are also completely ignoring the inertia and time-lag of CO2 induced warming.
Is this the new theory for why CO2 lags temperature?
Stevengoddard,
So you are saying that unless I know who killed person A, I cannot possibly know who killed person B? I think that there might be something in error about that logic …
Tamino banned me for insisting there was a 1976 climate shift; I now see why; he believes it happened in 1975; fair enough; the devil is always in the detail.
Tamino was kind enough to calculate the different CO2 forcings for the two periods. His boundary dates are slightly different, but not so much that they would change the essentials: for the first period .25 w/m^2, for the second 2 w/m^2.
The extra 1.75 w/m^2 has had to go somewhere, or come from somewhere. Aerosols are mentioned,but I have asked on Open Mind if there are any measured aerosol levels which cover the preiods concerned without a taker.
It can’t be sun variations as the received wisdom is that the sun’s variation is insufficient. This leaves cloud and or aerosols from industry and volcanoes. Or albedo change I suppose.
Is there data (yes, yes, I know, it’s a collective noun in layman speech) about variation in aerosols? Not modelled ‘data’, real data. TIA.
JF
ATTN: All
RE: Climate Cycles: What the Russians say.
The English translation of the monograph “Cyclic Climate Changes and Fish Productivity” by L.B. Klayashtorin and A. Lyubushin can be dowloaded for free from:
http://alexeylybushin.narod.ru/Climate_Changes_and_Fish_Productivity.pdf?
This book is 224 pages and the Russian addition was published 2005. The English edition was published in 2007. The literature is covered through 2004 with a few references in 2005.
In the first two chapters, they show the results of their analyses of numerous time series of data related to climate such as air temperature, ocean oscillation indices, tree ring and sediment proxies, fish catches, etc.. They found that the earth has a climate cycle of warm and cool phases with periodicity of 50-70 years with an average of 60 years which has a 30 year cool phase and 3o year warm phase.
Since the begining of the instumental record of reliable temperature data in 1880, the cool phases were 1880=1910 and 194o-1970 , and the warm phases were 1910=1940 and 1970-2000. They predict that 2000-2030 will be a cool phase.
In Fig 2.22 (p 52) and Table 2 (p 53), they show that increasing world fuel consumption has no effect on fluctulating gobal temperature anomalies.
In Chapters 3-6 have detailed analyses of the influence of various aspects of climate cylcles on fish populations and catches in the world’s major fisheries.
Steve Goddard, nice work proving Phil Jones wrong using his own graph data!
It’s even worse than Girma Orssengo pointed out with his two articles in the past year. Your article is a nice addition to Girma’s articles. I’d love to see the three articles integrated and published in a peer review journal.
Predictions Of Global Mean Temperatures & IPCC Projections
By Girma Orssengo, B. Tech, MASc, PhD
http://wattsupwiththat.com/2010/04/25/predictions-of-global-mean-temperatures-ipcc-projections/
A primer for disproving IPCC’s theory of man made global warming using observed temperature data
By Girma Orssengo, B. Tech, MASc, PhD
http://wattsupwiththat.com/2010/08/01/a-primer-for-disproving-ipcc%E2%80%99s-theory-of-man-made-global-warming-using-observed-temperature-data/
Picking Carbonated Cherries In 1975
By Steve Goddard
http://wattsupwiththat.com/2010/08/22/picking-carbonated-cherries-in-1975/
Carrick says:
August 22, 2010 at 10:44 pm
Other forcings play a role besides CO2, and prior to 1980 it’s generally agreed in the climate community that sulfates balanced CO2.
I’m not sure that this is “generally agreed” since the evidence suggests that the “sulfate” effect was not a factor in the 1945-1975 cooling (or non-warming). The effect of sulfate (or sulphate) aerosols is regionally specific, i.e. the majority of them are washed out of the atmosphere within a few weeks. Productions of aerosols was predominantly limited to the mid latitude bands in the NH.
However, the GISS temperature record for the 1945-75 period is characterised by sharp cooling (~1 deg) in the arctic – well away from the industrialised regions. Fuurthermore any aerosols that did make it to the arctic would have caused warming not cooling via the effect of Arctic Haze . See http://en.wikipedia.org/wiki/Arctic_haze which cites a numbe rof studies which detail the warming effect of aerosols in the arctic including this
“According to Tim Garrett, an assistant professor of meteorology at the University of Utah, mid-latitude cities contribute pollution to the Arctic, and it mixes with thin clouds, allowing them to trap heat more easily. Garrett was involved in the study of Arctic haze at the university. The study found that during the dark Arctic winter, when there is no precipitation to wash out pollution, the effects are strongest, because pollutants can warm the environment up to three degrees Fahrenheit
While, between 1945 and 1975, the arctic was cooling dramatically the NH mid latitude regions were experiencign a very modest cooling. There was little or no difference between heavily industrialised regions and rural regions.
It does seem likely that cyclical factors (e.g. ocean oscillations) have influenced 20th century climate and probably the 19th century climate as well, but there is also an underlying warming trend not connected with the ‘cycles’, e.g. 1995-2005 is ~0.4 deg warmer than 1935-45. If we assume that the residual (non-cyclical) increase is due to ~1 w/m2 forcing from enhanced ghgs over that period it implies a temperature increase of 1-1.5 deg C for a doubling of CO2.
Robert says:
August 23, 2010 at 12:16 am
“Okay Goddard,”
That’s Mr.Goddard to you. You impress no one and diminish your argument by your rudeness. Did your mother not teach you the most basic of manners?
Carrick says:
August 22, 2010 at 10:44 pm
Other forcings play a role besides CO2, and prior to 1980 it’s generally agreed in the climate community that sulfates balanced CO2. Hence Tamino’s comment about the “modern warming period starting in 1975″.
Little questionairre:
Sulphates hid the warming prior to 1975, 1980.
CO2 is not a unique drover but adds to the total forcings leading to eventual tipping point(s).
Post 1980 warming was caused by ______________________________ ?
Post 1998 cooling was caused by ______________________________ ?
Bonus: 1910-1940 warming was caused by _________________________ ?
It is also interesting to overlay an historical comparision of the course of the Climate Science debate. With the new spectrum data on greenhouse gases in the 1920s and 30s, the CO2-forcing theory (mainly due to volcanism) for geological climate change collapsed.
Then along came Callendar in 1938 (and later papers) proposing that the observed warming from the late 19th cent through the 1940s was in a large part caused by fossil fuel emissions. The establishment climate scientists gave this outsider a hearing (even asked him to join their club!) but their rounded criticism of his theory is as familiar to us today and it remain valid.
Then came the cooling of the 60s and 70s and the Ice Age scare prompted by scientists (not just Schneider). And then the warming in the 1980s, and once again the AGW argument (lead by the powerful science-advocacy of Hansen and Schneider etc).
What is curious for the sceptic is the way the Alarmist attempt to deal with the problem of Callendar. On the one hand he is a hero for first making a proper case of AGW, but on the other hand giving attention to him causes problems. For, since 1995, the IPCC etc have held to the claim that AGW only kicked in after the 1970s cooling. If they gave an earlier date causes attention this would drawn to climate cycles, but also to Callendar’s response in the last cycle. On the post 1970s argument, they have to say that Callendar was wrong…and that his critics were right…and yet that today’s critics making the same points are wrong.
With the onset of the harsh winters of the early 1960s (especially 1963), Callendar himself was as aware as any that it was difficult to sustain a theory of warming when it felt like the warming had stops. The same thing is happening right now, but there is so much more momentum. What will happen this time is anybody’s guess — but it sure wont collapse as easily and quietly as it did last time.
I was there, I saw the butterfly flap it’s wings in 1975.
The graph shows a spike at year 1998, yet no spike in the 1930`s which data appears to suggest are the hottest years on record globaly.
http://buythetruth.wordpress.com/2009/06/11/crops-and-130-years-of-climate-records/
I thought the IPCC position that changes in TSI were responsible for the 1910 – 1940 warming had been discredited.
I’m sure Leif Svalgaard pointed out that the current understanding of TSI variation is that it changes much less than previously supposed (variously and separately demonstrated by Wang, Preminger, Kriv and Svalgaard).
The IPCC based its case on an obsolete paper by Hoyt and Schatten (1993). Reference may be made to more recent work by Lean, also erroneously showing increasing TSI from ~1900 to ~1940. I think this was the case in TAR at any rate, and AR4 seems to gloss over the whole thing with words to the effect that the role of TSI may not be as large as previously thought.
My understanding is that the cause of the 1910 – 1940 warming is NOT known.
Dominic
All these temperature graphs are total crap, the weather stations measure the micro climate around them, if they are situated at airports they are measuring the temperature of the tarmac at the airport, in cities they measure the temperature of the buildings. There are hundreds of pristine rural stations with long records world wide that can be used to verify the accuracy of this suspect warming, ever wonder why the warmers dont want to go down that road. If you are trying to measure the temperature of the natural environment, you dont go to an airport or a city to do that.
If 300-310 ppm caused a 0.5C increase, and 340-390 ppm caused a 0.5C increase, and the effect of CO2 concentration is known to be logarithmic, it shouldn’t be too hard (for someone cleverer than me) to fit a curve to these numbers, and so work out what additional increase is required for the IPCC’s worst-case 7C increase over the next century.
I suspect the required increase might be quite high.
R. Gates says:
August 22, 2010 at 10:28 pm
Please post to let us know how Tuesday goes. Yesterday’s high was 12 F above average, Tuesday is forecasted about -18 F above average.
If you don’t like the weather in Colorado, wait a few hours…it’ll change.
-Scott