UPDATE from Girma: “My title should have been ‘How to arrive at IPCC’s climate sensitivity estimate’ instead of the original”
Guest essay by Girma Orssengo, PhD
1) IPCC’s 0.2 deg C/decade warming rate gives a change in temperature of dT = 0.6 deg C in 30 years
IPCC:
“Since IPCC’s first report in 1990, assessed projections have suggested global average temperature increases between about 0.15°C and 0.3°C per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C per decade, strengthening confidence in near-term projections.”
Source: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html
2) The HadCRUT4 global mean surface temperature dataset shows a warming of 0.6 deg C from 1974 to 2004 as shown in the following graph.
Source: http://www.woodfortrees.org/plot/hadcrut4gl/from:1974/to:2004/trend/plot/hadcrut4gl/from:1974/to:2005/compress:12
3) From the following Mauna Loa data for CO2 concentration in the atmosphere, we have CO2 concentration for 1974 of C1 = 330 ppm and for 2004 of C2=378 ppm
Source: http://www.woodfortrees.org/plot/esrl-co2/compress:12
Using the above data, the climate sensitivity (CS) can be calculated using the following proportionality formula for the period from 1974 to 2004
CS = (ln (2)/ln(C2/C1))*dT = (0.693/ln(378/330))*dT = (0.693/0.136)*dT = 5.1*dT
For change in temperature of dT = 0.6 deg C from 1974 to 2004, the above relation gives
CS = 5.1 * 0.6 = 3.1 deg C, which is IPCC’s estimate of climate sensitivity and requires a warming rate of 0.2 deg C/decade.
IPCC’s warming rate of 0.2 deg C/decade is not the climate signal as it includes the warming rate due to the warming phase of the multidecadal oscillation.
To remove the warming rate due to the multidecadal oscillation of about 60 years cycle, least squares trend of 60 years period from 1945 to 2004 is calculated as shown in the following link:
Source: http://www.woodfortrees.org/plot/hadcrut4gl/from:1945/to:2004/trend/plot/hadcrut4gl/from:1945/to:2005/compress:12
This result gives a long-term warming rate of 0.08 deg C/decade. From this, for the three decades from 1974 to 2004, dT = 0.08* 3 = 0.24 deg C.
Substituting dT=0.24 deg C in the equation for Climate sensitivity for the period from 1974 to 2004 gives
CS = 5.1* dT = 5.1* 0.24 = 1.2 deg C.
IPCC’s climate sensitivity of about 3 deg C is incorrect because it includes the warming rate due to the warming phase of the multidecadal oscillation. The true climate sensitivity is only about 1.2 deg C, which is identical to the climate sensitivity with net zero-feedback, where the positive and negative climate feedbacks cancel each other.
Positive feedback of the climate is not supported by the data.
UPDATE:
To respond to the comments, I have included the following graph
Source: http://www.woodfortrees.org/plot/hadcrut4gl/mean:756/plot/hadcrut4gl/compress:12/from:1870/plot/hadcrut4gl/from:1974/to:2004/trend/plot/esrl-co2/scale:0.005/offset:-1.62/detrend:-0.1/plot/esrl-co2/scale:0.005/offset:-1.35/detrend:-0.1/plot/esrl-co2/scale:0.005/offset:-1.89/detrend:-0.1/plot/hadcrut4gl/mean:756/offset:-0.27/plot/hadcrut4gl/mean:756/offset:0.27/plot/hadcrut3sh/scale:0.00001/offset:2/from:1870/plot/hadcrut4gl/from:1949/to:2005/trend/offset:0.025/plot/hadcrut4gl/from:1949/to:2005/trend/offset:0.01
I have got a better estimate of the warming of the long-term smoothed GMST using least squares trend from 1949 to 2005 as shown in the above graph, which shows the least squares trend coincides with the Secular GMST curve for the period from 1974 to 2005. For this case, the warming rate of the least squares trend for the period from 1949 to 2005 is 0.09 deg C/decade.
This gives dT = 0.09 * 3 = 0.27 deg C, and the improved climate sensitivity estimate is
CS = 5.1*0.27 = 1.4 deg C.
That is an increase in Secular GMST of 1.4 deg C for doubling of CO2 based on the instrumental records.
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This is not “How the IPCC arrived at climate sensitivity of about 3 deg C instead of 1.2 deg C.”
If you want to know how the IPCC arrived at climate sensitivity of about 3 deg C, I recommend reading the IPCC report: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-6.html
Don’t think of publishing this as a paper, if you want to keep your academic career….
The multi-decadal oscillation of the GMST has been described by Swanson et al [1]:
“Temperatures reached a relative maximum around 1940, cooled until the mid 1970s, and have warmed from that point to the present. Radiative forcings due to solar variations, volcanoes, and aerosols have often been invoked as explanations for this non-monotonic variation (4). However, it is possible that long-term natural variability, rooted in changes in the ocean circulation, underlies much of this variability over multiple decades (8–12).”
After removing the multi-decadal oscillation, Wu et al have reported their result for the long-term warming rate [2]:
“…the rapidity of the warming in the late twentieth century was a result of concurrence of a secular warming trend and the warming phase of a multidecadal (~65-year period) oscillatory variation and we estimated the contribution of the former to be about 0.08 deg C per decade since ~1980.”
This long-term warming rate result of 0.08 deg C/decade by Wu et al has been confirmed by Tung and Zhou [3]:
“The underlying net anthropogenic warming rate in the industrial era is found to have been steady since 1910 at 0.07–0.08 °C/decade, with superimposed AMO-related ups and downs that included the early 20th century warming, the cooling of the 1960s and 1970s, the accelerated warming of the 1980s and 1990s, and the recent slowing of the warming rates.”
References
[1] Swanson et al. (2009)
Long-term natural variability and 20th century climate change
http://www.pnas.org/content/106/38/16120.full.pdf+html
[2] Wu et al. (2011)
On the time-varying trend in global-mean surface temperature
http://bit.ly/10ry70o
[3] Tung and Zhou (2012)
Using data to attribute episodes of warming and cooling in instrumental records
http://www.pnas.org/content/110/6/2058
All sensitivity figure are wrong, because there is no linkage between CO2 and temperature.
REPLY: John O’Sullivan, leader of the Principia cult, there’s no need to hide behind a fake email address. We always know who you are here.
MX record about cutestudio.net exists.
Connection succeeded to postoffice.omnis.com SMTP.
220 postoffice.omnis.com ESMTP Postfix – (mail-hub-e.omnis.com)
> HELO verify-email.org
250 mail-hub-e.omnis.com
> MAIL FROM:
=250 2.1.0 Ok
> RCPT TO:
=550 5.1.7 : Sender address rejected: undeliverable address: host mail.verify-email.org[66.36.231.122] said: 553 5.3.0 … No such user here (in reply to RCPT TO command)
– Anthony
“Positive feedback of the climate is not supported by the data.” Which is why it has taken more than $100 billion in research grants, and over two decades of overt government pressure, to “balance” the bad data with the reluctant physical reality. OUR ‘outcome based education’ system has achieved the desired low information voter, with near total scientific illiteracy. OUR advocacy media has marketed the fable. OUR grant system has bribed the more than willing university system and sustainable product industry. OUR EPA extortion network has provided the muscle, combining to create the BIGGEST BUNCO OPERATION of all time. Thought far from the founders intentions, you must admit OUR crime syndicate government is the most elaborate in all history. Unfortunately for the public, you are not the beneficiaries of OUR racketeering.
The IPCC are trying to conserve the worlds natural resources.
See who is exploiting the worlds natural resources in the fourth paragraph:
http://en.wikipedia.org/wiki/Natural_resource
Well, at least your heading in the right direction. Alert me when you get to climate sensitivity of zero and I’ll pay attention.
Then add some ocean heat and ice sheet adjustment and you probably end up around 1.5 C.
While interesting, this analysis assumes cause and effect which has not been empirically established. “Correlation does not prove causation” and feed back from water vapor, clouds, etc. is ignored. Although the physics is solid it is incomplete and anthropogenic vs natural is a long way from being resolved. This is more information to present to the jury but we are a long way from final summation much less a verdict.
“Although the physics is solid”
—————–
The world is not a simple physics equation. It is dynamic, not static. Thunderheads take heat and dump it above 90% of the CO2 “blanket”. Clouds form to reflecty heat from the sun.
There is no way that current models capture the complexity of the heat trapping/disbursement of the earth. Thats why 100% of them failed to predict the current lack of warming.
Baa Humbug says”Alert me when you get to climate sensitivity of zero and I’ll pay attention”
You may be interested in my extremely simplistic approach to this issue. Since no-one has measured a CO2 signal in any modern temperature/time graph, from standard singal to nosie ratio physics, there is a strong indication that the climate sensitivity of CO2 is indistinguishable from zero.
Unfortunately the 97% climate scientist consensus by crazy Cook claim is being promoted all over MSM so big fail for skeptic sites i’m afraid (just*type global warming in Google news).. Also Antony I think you got a case of blatant misrepresentation/passing off as you/copyright breach at the following site and should take them to court very quick http://vvattsupwiththat.blogspot.com/
REPLY: Oh I’m familiar with Dr. Russell Seitz and his parodies, but he’s not worth pursuing (much less paying attention to) for two reasons.
1. Streisand effect
2. Fair use law allows for use of materials specifically for the purpose of parody/criticism.
Waste of time, really, to pay any attention to him. – Anthony
Teddy Roosevelt a true progressive. Big business, bad big government good.
Latif and Keenlyside (2010)
A Perspective on Decadal Climate Variability and Predictability
The global surface air temperature record of the last 150 years is characterized by a long-term warming trend, with strong multidecadal variability superimposed. Similar multidecadal variability is also seen in other(societal important) parameters such as Sahel rainfall or Atlantic hurricane activity.
http://oceanrep.geomar.de/8744/1/Latif.pdf
Latif
Uncertainty in climate change projections
To some extent, we need to “ignore” the natural fluctuations, if we want to “see” the
human influence on climate. Had forecasters extrapolated the mid-century warming into the
future, they would have predicted far more warming than actually occurred. Likewise, the
subsequent cooling trend, if used as the basis for a long-range forecast could have erroneously
supported the idea of a rapidly approaching ice age. The scientific challenge is to quantify the
anthropogenic signal in the presence of the background climate noise. The detection of the
anthropogenic climate signal thus requires at least the analysis of long records, because we
can be easily fooled by the short-term natural fluctuations, and we need to understand their
dynamics to better estimate the noise level.
http://oceanrep.geomar.de/9199/1/JGE.pdf
To: Kelvin Vaughan
OK, I read the 4th paragraph, which says:
“There is much debate worldwide over natural resource allocations, this is partly due to increasing scarcity (depletion of resources) but also because the exportation of natural resources is the basis for many economies (particularly for developed nations such as Australia).”
We sometimes forget that all of the world’s natural resources are controlled by national governments, except for privately owned mineral rights on privately owned land in the United States. Ironically, it is the individual owners of the small portion of private mineral interests in the United States who have turned the energy market upside down with fracked natural gas, drastically reducing energy costs for everyone on the globe.
If you want to change the way natural resources are used globally, look to leadership in national governments. If they are elected they have the power to do what you want, even though they would like for you to think it is private energy sector interests who to blame for everything. If they are not elected by you, you might want to think about changing your government to some form of elected representative democracy. The last place you want to look to for solutions is the United Nations and the IPCC, which is about as far as you can get from a democracy. Think of the UN as a World Chamber of Commerce, originally designed and still controlled by the world’s dictators and world’s financial elite — the 1% of the 1% of the 1%.
What ever happened to ’cause-and-effect’ in science? Just because temperature went up and CO2 also went up over the same period doesn’t make a basis for calculating how much temperature will go up as CO2 increases! This whole analysis is based on the false premise that temperature is a function of CO2. Why don’t we do the same analysis for the period 1945 to 1977 and calculate how much COOLING occurs with increase in CO2? And why don’t we calculate for the period 1880 to 1915 how much COOLING occurs with increase in CO2? And why don’t we calculate for the Maunder Minimum how much COOLING occurs with increase in CO2? You get the idea–the notion that temperature is a function of CO2 is invalided until you first show a cause-and-effect relationship between the two!
“To remove the warming rate due to the multidecadal oscillation of about 60 years cycle, least squares trend of 60 years period from 1945 to 2004 is calculated.”
Shouldn’t the trend over a complete 60 year cycle be zero?
“CS = 5.1 * 0.6 = 3.1 deg C, which is IPCC’s estimate of climate sensitivity and requires a warming rate of 0.2 deg C/decade.”
Is this actually how the IPCC came up with 3.1 °C / doubling ?????
If it is, all I have to say is Wow , that is some fine cherry picking !
How about we cherry pick from the 50’s to late 70’s ?? – then we’ll get a negative sensitivity :))
This short period is the steepest period of warming & obviously will give the highest sensitivity (and cause the greatest alarm). If you take a similar approach, with no de-trending, over the industrial age, you come up with 1.8° C / doubling
Its pretty easy to see by looking at the two earlier rises (1850 – 1880) (1910 – 1945), and comparing them to the (1975 – 2000) rise, that the MOST you get is 1C per doubling. I don’t really like the analysis method presented here, though.
Okay, just posting a link puts you in the spam box. Trying again.
New Discovery: NASA Study Proves Carbon Dioxide Cools Atmosphere
This is not how the IPCC arrived at 3C. They give the reasons on their website for anyone who wants to look them up.
The SSTs peaked in about 2003 and the earth has been in a cooling trend cooling since then.The peak was not only a peak in the 60 year cycle but also quite likely a peak in the solar millennial cycle which must be included in any calculations. .It is not possible to calculate the effect of anthropogenic CO2 until we know within closer limits what the natural variation is.For example if you look at the ice core data for the Holocene and if you believe that CO2 is the climate driver you would have to conclude that on a scale of thousands of years CO2 was an Ice House – not a green house gas.For the data and an estimate of the coming cooling for the next few hundred years check the post”Climate Forecasting for Britain’s Seven Alarmist Scientists and for UK Politicians.” at
http://climatesense-norpag.blogspot.com
The reality is, we can’t really know what the climate sensitivity is, nor can we test it anywhere outside of a lab, which is not reality!!! The REASON, the temperature metrics are all screwed up with adjustments.
NOTE … in this post, and every other post, this or that model or theory is compared to Hadcrut, or GISS, or NOAA,, all of which are contaminated and adjusted. Occassionally they will throw in the Satelite Metics, but they dont’ go back far enough to measure anything outside of the late 20th century warming, which is only data collected over a single phase of climate forcings; high solar input, single phase of PDO, AMO, etc…. I think that Anthony, and any other person versed in science would agree that a mere 35 years is not a sufficient sample to determine the climate sensitivity for longer periods of time, like centuries.
Because of this very real fact, the real climate sensitivity to CO2 is whatever it is the lab .. which I think I”ve seen about 1C thrown around. ALL other changes in the earths temperature, either up or down, are due to nature. PERIOD. Further, as stated many times by others, CO2 sensitivity is log, thus, we will have to reach 1000 ppm to increase the temp by 2C, and even there, the probability of the actual temp metric reaching that point is, IMO, very low, because nature does have feedbacks.
Girma, thanks for the post. You say:
And just what is the “multidecadal oscillation” when it is at home? How are you “removing the warming rate due to the multidecadal oscillation” by calculating its linear trend? And how have you determined that we are in the “warming phase of the multidecadal oscillation”? Exactly when did said warming phase start, and when will it end?
I’m not sure whether the problem is in your descriptions or in your procedures, Girma, but I can’t follow your logic there. Like someone said above … don’t quit your day job quite yet …
w.
Re Jim Cripwell — shouldn’t that be “singal to nosie raito” ??