Guest post By Girma Orssengo, MASc, PhD
Comparison of the claims by the Intergovernmental Panel on Climate Change (IPCC) of 1) “Most of the observed increase in global average temperatures since the mid-20th century is very likely” man made, and 2) “For the next two decades a warming rate of 0.2 deg C per decade is projected” are shown in this article not to be supported by the observed data, thus disproving IPCC’s theory of man made global warming.
FIRST IPCC CLAIM
In its Fourth Assessment Report of 2007, IPCC’s claim regarding global warming was the following [1]:
Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
Let us verify this claim using the observed data from the Climate Research Unit (CRU) of the University of East Anglia [2]. In this claim, “mid-20th century” means year 1950. As a result, according to the IPCC, global warming since 1950 is mostly man made.
To verify the claim that global warming since 1950 is mostly man made, we may compare the global warming rate in degree centigrade (deg C) per decade in one period before 1950 to that of a second period after 1950 to determine the effect of the increased human emission of CO2. To be able to do this, we need to identify these two periods, which may be established from the Global Mean Temperature Anomaly (GMTA) data of the CRU shown in Figure 1.
In Figure 1, the GMTA could be visualized as the sum of a Linear GMTA that has an overall warming rate of 0.6 deg C per century and an Oscillating GMTA that oscillates relative to this overall linear warming trend line. This Oscillating GMTA indicates the relative warming and cooling phases of the globe.
As our objective is to verify the claim that global warming since 1950 is man made, we need to identify two global warming phases before and after 1950. To clearly see the global warming and cooling phases, we plot just the Oscillating GMTA, which is the GMTA relative to the overall linear warming trend line shown in Figure 1. This can be done by using an online software at www.woodfortrees.org by rotating the overall linear warming trend line to become horizontal by using a detrend value of 0.775 so that the Oscillating GMTA has neither overall warming nor cooling trend. The noise from the Oscillating GMTA is then removed by taking five-years averages (compress = 60 months) of the GMTA. The result thus obtained is shown in Figure 2.
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Figure 2 shows the following periods for relative global cooling and warming phases:
- 30-years of global cooling from 1880 to 1910
- 30-years of global warming from 1910 to 1940
- 30-years of global cooling from 1940 to 1970
- 30-years of global warming from 1970 to 2000
If this pattern that was valid for 120 years is assumed to be valid for the next 20 years, it is reasonable to predict:
- 30-years of global cooling from 2000 to 2030
Figure 2 provides the two global warming phases before and after 1950 that we seek to compare. The period before 1950 is the 30-years global warming period from 1910 to 1940, and the period after 1950 is the 30-years global warming period from 1970 to 2000.
Figure 2 also provides the important result that the years 1880, 1910, 1940, 1970, 2000, 2030 etc are GMTA trend turning points, so meaningful GMTA trends can be calculated only between these successive GMTA turning point years, which justifies the calculation of a GMTA trend starting from year 2000 provided latter in this article.
Once the two global warming periods before and after mid-20th century are identified, their rate of global warming can be determined from the GMTA trends for the two periods shown in Figure 3.
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According to the data of the CRU shown in Figure 3, for the 30-years period from 1910 to 1940, the GMTA increased by an average of 0.45 deg C (3 decade x 0.15 deg C per decade). After 60 years of human emission of CO2, for the same 30-years period, from 1970 to 2000, the GMTA increased by an average of nearly the same 0.48 deg C (3 decade x 0.16 deg C per decade). That is, the effect of 60 years of human emission of CO2 on change in global mean temperature was nearly nil, which disproves IPCC’s theory of man made global warming.
SECOND IPCC CLAIM
In its Fourth Assessment Report of 2007, IPCC’s projection of global warming was the following [5]:
For the next two decades, a warming of about 0.2 deg C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1 deg C per decade would be expected.
Let us verify this projection using the observed data from the CRU [2]. This may be done by comparing the global warming rate between the last two decades as shown in Figure 4. In this figure, the global warming rate decelerated from 0.25 deg C per decade for the period from 1990 to 2000 to only 0.03 deg C per decade for the period since 2000, which is a reduction by a factor of 8.3, which further disproves IPCC’s theory of man made global warming. If the current global warming trend continues, the GMTA will increase by 0.27 deg C (0.03 x 9) by 2100, not the scary 2.4 to 6.4 deg C of the IPCC.
Note that the projection for the current global warming rate by the IPCC was 0.2 deg C per decade, while the observed value is only 0.03 deg C per decade. As a result, IPCC’s Exaggeration Factor is 6.7.
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SUMMARY
As shown in Figures 3 and 4, claims by the IPCC of 1) “Most of the observed increase in global average temperatures since the mid-20th century is very likely” man made, and 2) “For the next two decades a warming rate of 0.2 deg C per decade is projected” are not supported by the observed data, thus disproving IPCC’s theory of man made global warming.
According to the CRU data shown in Figure 3, the 30-years global warming from 1970 to 2000, after human emission of CO2 for 60 years, was nearly identical to the 30-years global warming from 1910 to 1940. In the intervening 30-years, there was a slight global cooling from 1940 to 1970. Furthermore, since year 2000, as shown in Figure 4, the global warming rate decelerated by a factor of 8.3 compared to the decade before. This is the story of global mean temperature trends for the last 100 years!
Does not the observed data in Figures 1 and 2 show a cyclic global mean temperature pattern with an overall linear warming rate of 0.6 deg C per century?
Dear citizens of the world, where is the catastrophic man made global warming they are scaring us with?
Or is the scare a humongous version of the “Piltdown man”?
REFERENCES
[1] IPCC: “Most of the observed increase in global average temperatures since the mid-20th century is very likely” man made
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-understanding-and.html
[2] Global Mean Temperature Anomaly from Climate Research Unit of the University of East Anglia (GRAPH)
[2] Global Mean Temperature Anomaly from Climate Research Unit of the University of East Anglia (RAW DATA)
[3] Oscillating Global Mean Temperature Anomaly
[4] Comparison of global warming rates before and after mid-20th century (GRAPH)
[4] Comparison of global warming rates before and after mid-20th century (RAW DATA)
[5] IPCC: “For the next two decades, a warming of about 0.2 deg C per decade is projected”
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html
[6] Deceleration of global warming rate in the last two decades
Laws of Nature says:
August 2, 2010 at 3:25 am
‘Where the X1,2,3 are all other (natural!?) effects which happened during the increase of CO2. Gavin points out, that these estimates might have huge error bars!
(Actually I thought direct the forcing for different CO2 levels is known quite well)
In any case it seems to me, that the IPCC seems to count on almost 1C warming which is caused by the actual CO2-level but somehow delayed/hidden (the lack of evidence for that is what K. Trenberth called a “travesty”)’
Ah, yes. The old 2.5 “Amplification Number” that someone pull out their hiney to “balance the books” for “positive feedback”.
If I did that in my business, I would be out of business and/or in jail.
So what have we got?
The sun has a better correlation to “temperature”than CO2 .
The oceans have not been heating up as per hypothesis.
No “hot spot’ in the upper troposphere unless you correct for “wind chill” .
Wind has a much larger affect on evaporation than CO2.
Don’t know how, why, where or when clouds will form or if they will produce rain.
PDO, AMO, La Nina, El Nino, and aerosols (which could either heat or cool) has a stronger effects on “temperatures” than CO2.
We still don’t know what cause the MWP which may have warmer than today but not as warm as the Roman Warm Period. Like wise, we don’t why “temperature” cooled down from the Roman or Mid Evil Period.
We do know the Mediterranean Sea was larger than today and that there were three lakes in the Sierra desert 8000 years ago.
Climate Models have never been V & V.
Melting glaciers are uncovering old mine site in France.
But “CO2 Drive the Climate” science is settled and we need to regulate CO2. Shut up and give us more money so we can spread the wealth.
The EPA is getting an 20% increase in funding. Got to pay off all those scientist promoting more regulations based more on opinions (Polar Bears will die) than facts.
Oh yes. One more “thing” for the scientist that want all this regulations.
Be warned. The regulations you seek will turn around and bit you or your children or your grand kids or their grand kids. It just a matter of time.
What freedom are you NOT WILLING to give up before you make a stand?
J.Hansford, DirkH, Vorlath, Ed Caryl, JamesS, DoubtingThomas, and Tenuc:
To varying degrees you miss my point which simply is that this essay assumes correlation is causation in it’s refutation of the “IPCC first claim.” Read carefully and avoid jumping to conclusions that I support the IPCC or that I think CO2 is the sole or even primary cause of warming (neither of which I do, btw). I’m only criticizing the author’s naive argument here. He needs to do better. Jumping to the defense of poor arguments and misrepresenting criticism of them does nothing to advance understanding.
barry: At the woods for trees site, you can run trends for solar influence for the periods in question.
Martin: Indeed they can. If we do a little cherry picking.
Why on earth are you cherry-picking? I used the same time periods as the top post did. You did not.
Up until then nobody mentioned it. So it’s a red herring he used to patch up the infallible hypothesis of AGW.
What, are you saying that nobody mentioned it upthread of Boris’s post, or that this wasn’t mentioned in the early part of the 20th century?
Well, the former is irrelevant, and the latter is irrelevant because scientists had not attempted to plot the global temperature in the early 20th century.
I can’t make sense of much of your post. I pointed out some anomalies re the advice in the top post, in order to encourage enquiry. Ignorance can be cured by curiosity. There is no cure for a lack of curiosity.
I’m still willing to link up to sources on attribution if any genuine enquiry is forwarded.
Although being very resonable observations, unfortunately it will take very hard evidence to convince the warming crew they have it all wrong – they have too much at stake, especially in terms of reputation. Ironically, very little evidence was required to support the theory, but to dispel it will be a different matter. They will have an excuse for everything. And the harder they dig in, the harder it will be to convince them they’re wrong.
It’s quite understandable once a person examines the year to year history of ppm CO2 concentration. 25ppm rise 1880-1950. 50ppm rise 1950-2000. Additionally one must understand how insulation works to see that it takes twice as much additional Co2 to get the same effect as the last increment.
In short, the two periods are perfectly consistent with each other and with hypothetical anthropogenic CO2 warming ocurring over the entire period at the rate of about 0.05C/decade or one half degree per century.
You have me understood. I’m aware of the idea that CO2 rise is so rapid that equilibrium surface temp might be as much as 50 or 100 years in the future. In other words energy from the sun reaching the surface is more than what’s being radiated away and will persist until surface temp rises to reestablish equilibrium.
How can that be put to the test?
As far as I know investigators are seaching for what’s commonly called the “missing heat”. So far it hasn’t been found. The only place it can be stored “out of sight” is in the ocean.
It’s difficult to determine if the total oceanic heat content is rising except perhaps through very precise sea level measurement so I’ve been monitoring progress in getting reliable paleotide data and precision current measurements.
So far it doesn’t look like the ocean is doing anything other than the expected thermal expansion commensurate with the surface temperature record – no missing heat that would make it thermally expand faster than expected.
After this and similar posts (eg. Goddard’s work), the CAGW’s are reduced from “I believe in ghosts” to “There still could be ghosts, since you have not proved they do not exist.
Bill Illis, 7:00 AM
Good post, but left out the Urban Heat Island effects on the “Raw Data” on which the trends are based. Also, airport siting effects. Subtract a modest amount from the 0.7C for UHI and Airport siting, and along with the other effects/cycles you mention, there is not much room left in the data for direct CO2 forcing, much less any postive feedbacks from CO2 forcing.
Excellent and clearly expressed article.
When the complex concept of Man-made global warming that can never be falsified due to the contrary qualities assigned to it by its proponents is given some consideration, suspicions arise that the UN strong-armed various governments to entice tame scientists to provide the unfalsifiable scenario to enable the UN to take over the reins (and the Revenue) of national governments around the world and redistribute that Revenue to favoured nations. I am beginning to think that many scientists are ‘willing fools’, eager to do ‘science’ for gain.
Thanks are due to WUWT for providing a sane, rational and gentlemanly forum which will allow the scientific truth to emerge.
barry says:
August 2, 2010 at 8:18 am
Why on earth are you cherry-picking? I used the same time periods as the top post did. You did not.
You used a solar proxy to try and dismiss the essence of the article. The article only noted that there was an apparent 30 year oscillation between global warming and cooling over the CRU data range. It noted the trend was up but all the steps up were of the same magnitude. Since the IPCC states:-
The article stated:-
The implication is that anthropogenic CO2 cannot be singled out as the driver of global warming because the long term trend has been rising since before industrialization. In order to explain how you can make such a claim you would need to identify the drivers of all the other upward steps in the data range and why they stopped at the onset of industrialization.
You cannot without throwing more ad-hoc hypotheses to patch up the already failed hypothesis.
I can’t make sense of much of your post. I pointed out some anomalies re the advice in the top post, in order to encourage enquiry.
You were doing nothing of the kind. You were using the post-modern science tactic of introducing ad-hoc hypotheses to discredit the writers observations. These are your words:-
Typical of the sloppy thinking that infests our sciences these days.
Chuck in a little bit of this, throw in a little bit of that and bingo, the train wreck that is AGW lives to fight another day.
Well, the former is irrelevant, and the latter is irrelevant because scientists had not attempted to plot the global temperature in the early 20th century.
So no one is doing any historic climate research? I know the tax funded overgrown university students aren’t doing any real climate research but surely there are some real scientists out there.
I’m still willing to link up to sources on attribution if any genuine enquiry is forwarded.
Please feel free to post any attributions you like. So long as they are in the public forum and not behind the pay wall of a coffee table magazines like Nature or New Scientist.
Isn’t the accepted premise amongst the proper scientific community that heat increase pre-dates any CO2 increase by a factor of 500-800 years. If this is the case, isn’t the recent increase in CO2 therefore attributable to the MWP and not AGW? Just a thought………….
A better procedure would be using a “Lie detector”
I wonder who organized nature and human emission of CO2 to swap sides exactly after 60 years to produce the same effect!
Well, only you, I think. It’s not as seen as one or the other in the literature.
Basically, solar activity increased during the early part of the instrumental record, supplementing the warming from CO2, such that the rate is similar to the morwe recent period, when the solar trend has been flat or slightly declining.
But that’s only a piece of the puzzle. There are other factors at play. Without assessing as much as possible, there isn’t enough data to draw any kind of conclusion.
Once again, it’s not an either/or situation. Solar activity, volcanic activity, industrial CO2 and aerosols and so on contribute to climate change. These effects have been teased out to the best of our ability, and should be read up on.
I just don’t agree that the OP is arguing or assuming that correlation is causation. I see his point as being “trend A is exactly the same as trend B, yet the IPCC says that trend B is caused mainly by human-produced CO2, while trend A was natural.”
I’d say that the IPCC has made that error first.
Isn’t the accepted premise amongst the proper scientific community that heat increase pre-dates any CO2 increase by a factor of 500-800 years. If this is the case, isn’t the recent increase in CO2 therefore attributable to the MWP and not AGW?
No.
CO2 increased by 100 ppm over 4200 years during the temperature rise out of the last ice age. We’ve had a 100 ppm increase in 150 years in the modern era.
Further, the planet warmed by 5 – 6C out of the last glaciation. Medieval warming – according to the highest figures suggested by skeptics – was barely half that.
Also, the isotopic ration of industrial CO2 is different to that naturally occurring. We can measure the anthropogenic portion of CO2 change, and we find that what we estimate from calculating how much we’ve burned, is a good match with chemical analysis.
Dear Dr. Orssengo,
I have quoted extensively from your “Predictions Of Global Mean Temperatures & IPCC Projections”, at http://www.oarval.org/ClimateChange.htm and http://www.oarval.org/CambioClima.htm (Spanish).
This is another very interesting article, I’m linking to it. Thanks!
Thanks again Anthony
Martin, your post is illogical, and you have misinterpreted my contribution and the thrust of the top post. I have no interest in sorting that out with you, but here are some scientific papers on attribution, most available in full text. There’s been plenty of work done on it.
http://agwobserver.wordpress.com/2010/03/25/papers-on-formal-attribution/
IPCC dedicate a whole chapter of the latest report to attribution:
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter9.pdf
If you have any curiosity in you, happy reading.
By concentrating on the temperature changes from trough to peak, you are ignoring the fact that the latest peak is higher than the 1940 peak. Since the radiative flux F required to maintain a temperature T is given by sigma * T^4, this little increase in temperature implies a higher flux. It is therefore not inconsistent with AGW hypothesis to have periods of similar temperature increases even though CO2 had little effect on the first. It is not inconsistent because the latest peak is at a higher absolute temperature and therefore requires a higher energy flux. It is the higher energy flux, or forcing, that is attributed to CO2.
Altough there are many arguments to discredit AGW, this isn’t one of them.
MartinGAtkins (#10:52)
Thanks a million for your excellent response to their questions.
I loved this one:
Chuck in a little bit of this, throw in a little bit of that and bingo, the train wreck that is AGW lives to fight another day.
First of all the HadCRUT3 temperature curve in Figure 1 is worthless and ought not to be used as indication of what the actual temperature did. The last thirty years that parallel satellite temperature curves can be shown to be entirely faked. In the eighties and nineties there was no warming, just temperature oscillations, up and down by half a degree until the super El Nino of 1998 showed up. But they finessed it into a rising curve called the “late twentieth century warming.” With the arrival of the super El Nino global temperature started to rise and in four years global mean rose by 0.3 degrees Celsius and then stabilized for six years. I have called it the twenty-first century high. Your Figure 4 recognizes it too in their curve but they actually raised up that entire section to line it up with the fake warming of the eighties and nineties. You can see their handiwork when you look at the two sides of the Super El Nino of 1998. It’s the last red peak in Figure 4. It and the twenty-first century high are at the extreme right in Figure 1. Both sides of the super El Nino are actually even but in their graph you can see how much fake warming is added to that section of the curve. This global temperature “standard” is from CRU section of the East Anglia University, lately the source of Climategate files. And older parts of the curve are also weird – thirties are not shown as particularly warm but World War II that follows is depicted as a heat wave. It should be the reverse – thirties that brought us the dust bowl should be warm and World War II cold. In any case, satellite data show that the only warming within the last thirty years was a stepwise warming that followed the super El Nino of 1998. Global mean temperature held steady during the eighties and nineties, then rose by 0.3 degrees within a four year period and became steady again for six years. It is this non-carboniferous warming that is responsible for the first decade of this century being the warmest on record, not some greenhouse effect that does not exist. Ferenc Miskolczi has shown that the greenhouse effect from addition of carbon dioxide to the atmosphere is physically impossible [E&E 21(4):243-246 (2010)].
barry,
The UN/IPCC is thoroughly corrupt. They refuse to follow their own written policies, and when Michael Mann was lead author he used the IPCC as his own personal CAGW propaganda organ to disseminate false information to support his bogus hockey stick papers, MBH98 and MBH99. Nothing has really changed since, which is not surprising with the organization being headed by a financially self-serving reprobate, or worse.
I’m not just spouting an opinion. The wrongdoing by Mann, Osborne, Briffa and the rest of the alarmist clique is extremely well documented in A.W. Montford’s The Hockey Stick Illusion. I challenge anyone to read it and argue that either Mann et al. or the IPCC are honest.
To quote your statement above: “If you have any curiosity in you, happy reading.”
Vince Causes (#12:22 pm)
According to the data, I accept that there is an overall linear warming of 0.6 deg C per century, but there is also an oscillation component that has to be added to it as shown in the following graph:
http://wattsupwiththat.files.wordpress.com/2010/04/orssengo3.png
Gary says:
August 2, 2010 at 8:15 am
“J.Hansford, DirkH, Vorlath, Ed Caryl, JamesS, DoubtingThomas, and Tenuc:
To varying degrees you miss my point which simply is that this essay assumes correlation is causation in it’s refutation of the “IPCC first claim.” Read carefully and avoid jumping to conclusions that I support the IPCC or that I think CO2 is the sole or even primary cause of warming (neither of which I do, btw). I’m only criticizing the author’s naive argument here. He needs to do better. Jumping to the defense of poor arguments and misrepresenting criticism of them does nothing to advance understanding.”
Gary, just to be clear that this is the IPCC statement you refer to.
“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. ”
Please explain how, given the long-term climate warming trend since the Little Ice Age, the rate of warming from the period starting 1920, is the same as the rate of warming seen since the mid-20th centuary? CO2 levels were vastly different between those two periods. This means that the extra CO2 had no statistical effect on temperature trend or the influence of CO2 was so weak in was drowned out by natural changes. In either case, the CAGW conjecture is falsified.
Dr. Girma Orssengo’s post is a brilliantly simple refutation of the IPCC’s extraordinary and risible claims. In science, the null hypothesis (in this case natural changes due to the vagaries of the deterministic chaos inherent in this complex system) remains in place, until a new conjecture makes better predictions. CAGW has failed and needs to be consigned to the waste bin.
Dr. Dave says:
August 1, 2010 at 6:43 pm
Dave, I alluded to this point in the swiss cheese post. The reported accuracy of anomaly trends is given with greater accuracy than the measurement from which the anomaly is derived. No respect for pure or commutative error is apparent.