NOTE: This post is important, so I’m going to sticky it at the top for quite a while. I’ve created a page for all Spencer and Braswell/Dessler related posts, since they are becoming numerous and popular to free up the top post sections of WUWT.
UPDATE: Dr. Spencer writes: I have been contacted by Andy Dessler, who is now examining my calculations, and we are working to resolve a remaining difference there. Also, apparently his paper has not been officially published, and so he says he will change the galley proofs as a result of my blog post; here is his message:
“I’m happy to change the introductory paragraph of my paper when I get the galley proofs to better represent your views. My apologies for any misunderstanding. Also, I’ll be changing the sentence “over the decades or centuries relevant for long-term climate change, on the other hand, clouds can indeed cause significant warming” to make it clear that I’m talking about cloud feedbacks doing the action here, not cloud forcing.”
[Dessler may need to make other changes, it appears Steve McIntyre has found some flaws related to how the CERES data was combined: http://climateaudit.org/2011/09/08/more-on-dessler-2010/
As I said before in my first post on Dessler’s paper, it remains to be seen if “haste makes waste”. It appears it does. -Anthony]
Update #2 (Sept. 8, 2011): Spencer adds: I have made several updates as a result of correspondence with Dessler, which will appear underlined, below. I will leave it to the reader to decide whether it was our Remote Sensing paper that should not have passed peer review (as Trenberth has alleged), or Dessler’s paper meant to refute our paper.
by Roy W. Spencer, Ph. D.
While we have had only one day to examine Andy Dessler’s new paper in GRL, I do have some initial reaction and calculations to share. At this point, it looks quite likely we will be responding to it with our own journal submission… although I doubt we will get the fast-track, red carpet treatment he got.
There are a few positive things in this new paper which make me feel like we are at least beginning to talk the same language in this debate (part of The Good). But, I believe I can already demonstrate some of The Bad, for example, showing Dessler is off by about a factor of 10 in one of his central calculations.
Finally, Dessler must be called out on The Ugly things he put in the paper.
(which he has now agreed to change).
1. THE GOOD
Estimating the Errors in Climate Feedback Diagnosis from Satellite Data
We are pleased that Dessler now accepts that there is at least the *potential* of a problem in diagnosing radiative feedbacks in the climate system *if* non-feedback cloud variations were to cause temperature variations. It looks like he understands the simple-forcing-feedback equation we used to address the issue (some quibbles over the equation terms aside), as well as the ratio we introduced to estimate the level of contamination of feedback estimates. This is indeed progress.
He adds a new way to estimate that ratio, and gets a number which — if accurate — would indeed suggest little contamination of feedback estimates from satellite data. This is very useful, because we can now talk about numbers and how good various estimates are, rather than responding to hand waving arguments over whether “clouds cause El Nino” or other red herrings. I have what I believe to be good evidence that his calculation, though, is off by a factor of 10 or so. More on that under THE BAD, below.
Comparisons of Satellite Measurements to Climate Models
Figure 2 in his paper, we believe, helps make our point for us: there is a substantial difference between the satellite measurements and the climate models. He tries to minimize the discrepancy by putting 2-sigma error bounds on the plots and claiming the satellite data are not necessarily inconsistent with the models.
But this is NOT the same as saying the satellite data SUPPORT the models. After all, the IPCC’s best estimate projections of future warming from a doubling of CO2 (3 deg. C) is almost exactly the average of all of the models sensitivities! So, when the satellite observations do depart substantially from the average behavior of the models, this raises an obvious red flag.
Massive changes in the global economy based upon energy policy are not going to happen, if the best the modelers can do is claim that our observations of the climate system are not necessarily inconsistent with the models.
(BTW, a plot of all of the models, which so many people have been clamoring for, will be provided in The Ugly, below.)
2. THE BAD
The Energy Budget Estimate of How Much Clouds Cause Temperature Change
While I believe he gets a “bad” number, this is the most interesting and most useful part of Dessler’s paper. He basically uses the terms in the forcing-feedback equation we use (which is based upon basic energy budget considerations) to claim that the energy required to cause changes in the global-average ocean mixed layer temperature are far too large to be caused by variations in the radiative input into the ocean brought about by cloud variations (my wording).
He gets a ratio of about 20:1 for non-radiatively forced (i.e. non-cloud) temperature changes versus radiatively (mostly cloud) forced variations. If that 20:1 number is indeed good, then we would have to agree this is strong evidence against our view that a significant part of temperature variations are radiatively forced. (It looks like Andy will be revising this downward, although it’s not clear by how much because his paper is ambiguous about how he computed and then combined the radiative terms in the equation, below.)
But the numbers he uses to do this, however, are quite suspect. Dessler uses NONE of the 3 most direct estimates that most researchers would use for the various terms. (A clarification on this appears below) Why? I know we won’t be so crass as to claim in our next peer-reviewed publication (as he did in his, see The Ugly, below) that he picked certain datasets because they best supported his hypothesis.
The following graphic shows the relevant equation, and the numbers he should have used since they are the best and most direct observational estimates we have of the pertinent quantities. I invite the more technically inclined to examine this. For those geeks with calculators following along at home, you can run the numbers yourself:
Here I went ahead and used Dessler’s assumed 100 meter depth for the ocean mixed layer, rather than the 25 meter depth we used in our last paper. (It now appears that Dessler will be using a 700 m depth, a number which was not mentioned in his preprint. I invite you to read his preprint and decide whether he is now changing from 100 m to 700 m as a result of issues I have raised here. It really is not obvious from his paper what he used).
Using the above equation, if I assumed a feedback parameter λ=3 Watts per sq. meter per degree, that 20:1 ratio Dessler gets becomes 2.2:1. If I use a feedback parameter of λ=6, then the ratio becomes 1.7:1. This is basically an order of magnitude difference from his calculation.
Again I ask: why did Dessler choose to NOT use the 3 most obvious and best sources of data to evaluate the terms in the above equation?:
(1) Levitus for observed changes in the ocean mixed layer temperature; (it now appears he will be using a number consistent with the Levitus 0-700 m layer).
(2) CERES Net radiative flux for the total of the 2 radiative terms in the above equation, and (this looks like it could be a minor source of difference, except it appears he put all of his Rcld variability in the radiative forcing term, which he claims helps our position, but running the numbers will reveal the opposite is true since his Rcld actually contains both forcing and feedback components which partially offset each other.)
(3): HadSST for sea surface temperature variations. (this will likely be the smallest source of difference)
The Use of AMIP Models to Claim our Lag Correlations Were Spurious
I will admit, this was pretty clever…but at this early stage I believe it is a red herring.
Dessler’s Fig. 1 shows lag correlation coefficients that, I admit, do look kind of like the ones we got from satellite (and CMIP climate model) data. The claim is that since the AMIP model runs do not allow clouds to cause surface temperature changes, this means the lag correlation structures we published are not evidence of clouds causing temperature change.
Following are the first two objections which immediately come to my mind:
1) Imagine (I’m again talking mostly to you geeks out there) a time series of temperature represented by a sine wave, and then a lagged feedback response represented by another sine wave. If you then calculate regression coefficients between those 2 time series at different time leads and lags (try this in Excel if you want), you will indeed get a lag correlation structure we see in the satellite data.
But look at what Dessler has done: he has used models which DO NOT ALLOW cloud changes to affect temperature, in order to support his case that cloud changes do not affect temperature! While I will have to think about this some more, it smacks of circular reasoning. He could have more easily demonstrated it with my 2 sine waves example.
Assuming there is causation in only one direction to produce evidence there is causation in only one direction seems, at best, a little weak.
2) In the process, though, what does his Fig. 1 show that is significant to feedback diagnosis, if we accept that all of the radiative variations are, as Dessler claims, feedback-induced? Exactly what the new paper by Lindzen and Choi (2011) explores: that there is some evidence of a lagged response of radiative feedback to a temperature change.
And, if this is the case, then why isn’t Dr. Dessler doing his regression-based estimates of feedback at the time lag or maximum response? Steve McIntyre, who I have provided the data to for him to explore, is also examining this as one of several statistical issues. So, Dessler’s Fig. 1 actually raises a critical issue in feedback diagnosis he has yet to address.
3. THE UGLY
(MOST, IF NOT ALL, OF THESE OBJECTIONS WILL BE ADDRESSED IN DESSLER’S UPDATE OF HIS PAPER BEFORE PUBLICATION)
The new paper contains a few statements which the reviewers should not have allowed to be published because they either completely misrepresent our position, or accuse us of cherry picking (which is easy to disprove).
Misrepresentation of Our Position
Quoting Dessler’s paper, from the Introduction:
“Introduction
The usual way to think about clouds in the climate system is that they are a feedback… …In recent papers, Lindzen and Choi [2011] and Spencer and Braswell [2011] have argued that reality is reversed: clouds are the cause of, and not a feedback on, changes in surface temperature. If this claim is correct, then significant revisions to climate science may be required.”
But we have never claimed anything like “clouds are the cause of, and not a feedback on, changes in surface temperature”! We claim causation works in BOTH directions, not just one direction (feedback) as he claims. Dr. Dessler knows this very well, and I would like to know
1) what he was trying to accomplish by such a blatant misrepresentation of our position, and
2) how did all of the peer reviewers of the paper, who (if they are competent) should be familiar with our work, allow such a statement to stand?
Cherry picking of the Climate Models We Used for Comparison
This claim has been floating around the blogosphere ever since our paper was published. To quote Dessler:
“SB11 analyzed 14 models, but they plotted only six models and the particular observational data set that provided maximum support for their hypothesis. “
How is picking the 3 most sensitive models AND the 3 least sensitive models going to “provide maximum support for (our) hypothesis”? If I had picked ONLY the 3 most sensitive, or ONLY the 3 least sensitive, that might be cherry picking…depending upon what was being demonstrated. And where is the evidence those 6 models produce the best support for our hypothesis?
I would have had to run hundreds of combinations of the 14 models to accomplish that. Is that what Dr. Dessler is accusing us of?
Instead, the point was to show that the full range of climate sensitivities represented by the least and most sensitive of the 14 models show average behavior that is inconsistent with the observations. Remember, the IPCC’s best estimate of 3 deg. C warming is almost exactly the warming produced by averaging the full range of its models’ sensitivities together. The satellite data depart substantially from that. I think inspection of Dessler’s Fig. 2 supports my point.
But, since so many people are wondering about the 8 models I left out, here are all 14 of the models’ separate results, in their full, individual glory:
I STILL claim there is a large discrepancy between the satellite observations and the behavior of the models.
CONCLUSION
These are my comments and views after having only 1 day since we received the new paper. It will take weeks, at a minimum, to further explore all of the issues raised by Dessler (2011).
Based upon the evidence above, I would say we are indeed going to respond with a journal submission to answer Dessler’s claims. I hope that GRL will offer us as rapid a turnaround as Dessler got in the peer review process. Feel free to take bets on that. 
And, to end on a little lighter note, we were quite surprised to see this statement in Dessler’s paper in the Conclusions (italics are mine):
“These calculations show that clouds did not cause significant climate change over the last decade (over the decades or centuries relevant for long-term climate change, on the other hand, clouds can indeed cause significant warming).”
Long term climate change can be caused by clouds??! Well, maybe Andy is finally seeing the light! 
(Nope. It turns out he meant ” *RADIATIVE FEEDBACK DUE TO* clouds can indeed cause significant warming”. An obvious, minor typo. My bad.)
R. Gates says:
September 11, 2011 at 8:45 am
Yes, this idea of us slipping back into a glacial period seems to be common fear of AGW skeptics. I think the RANGE of CO2 being between about 180 ppm and 280ppm has served the development of human civilization quite well over many tens of thousands of years. I don’t think you need to worry about any approaching glacial period with CO2 now nearing 400 ppm. Quite the opposite, we’ll find out if our food grains, and ocean food chain hold up enough in a much warmer world to support 7 billion people and rising.
Perhaps the most completely ignorant and uninformed comment we’ve seen from you ….
First – the sweeping generalization that we do not have to worry about a glacial period.
The historical record shows just how silly this claim is. As the following graphics show, and is well understood, the earth sees a clear cycle of glacial to inter-glacial periods occurring every appx 125,000+/- years – for at least the last half million years,
A chart of many of the variables:
http://www.trackforum.com/images/WARMING/Vostok+Temp-Co2-Mh4-Dust-Solar-Glacial.jpg
The profile of each glacial to inter-glacial period over the last 400,000+ years has been very similar. The temp during these periods is extremely similar – a sharp rise, followed by a warm peak and quick plunge back towards glacial lows. Except for this most recent warm period peak.
First – there has not been a sharp peak as with each other warm period maximum over the last 400,000 years. Instead temps rose at a normal fairly sharp rate but then stopped their rise well short of the normal peak. And instead of a sharp falloff post peak – temps have stabilized and remained within a narrow range of natural variability for the last appx 12,000 years.
Last 15,000 years Temp and CO2:
http://www.palisad.com/co2/slides/img7.gif
This despite CO2 continuing to rise. The graph above is IMO the smoking gun – that puts the lie to all of the warming alarmism. Warmists never seem to want to talk about the historical record – for good cause – the record shows temps rose sharply 12,000 years ago – and C02 followed, for a short period before leveling off appx 10,000 years ago – at same time temps leveled as well.
CO2 began rising again appx 3500 years ago, and has risen at appx the same rate as today for the last 2500 years. Despite that increase there has been NO statistically significant increase (or decrease) in temps over 12,000+/- years. Temps over the last 12,000 years have moved up AND DOWN in a range of natural variability. The current temps are not near the highest during that period, and are in fact close to the baseline over last 12,000 years.
Ice volume clearly tracks temps on a long term basis:
Ice Volume vs. Temps:
http://globalwarmingart.com/images/8/8f/Ice_Age_Temperature_Rev.png
Another clear correlation is airborne dust – temps directly track with airborne particulate matter – including volcanic disruptions and similar. We know that at least in the Northern hemisphere airborne particulate matter has been greatly reduced since the 70’s. Less airborne particulate allows more solar effect.
Vostok/CO2/Dust:
http://globalwarmingart.com/wiki/File:Vostok_Plot_png
And last – as to R. Gates comment on food … Co2 is plant FOOD … increased CO2 increases food production, in multiple ways. From increasing yields to, if one assume CO2 increases global temps, they also to the increase of temperate zones which increases landbase available for crop production.
All in all an extremely weak effort – one of his worst …
R Gates:
“Ah, but what a difference that 4% anthropogenic source has made…giving us 40% more CO2 in the atmosphere in just a few hundred years…sort of like compounding interest.”
I’m no scientist but even I know that statement is utter drivel.
R. Gates says:
September 11, 2011 at 11:49 am
Gary Mount says:
September 11, 2011 at 10:17 am
You may also be interested to know that about 96% of all global emissions of CO2 come from natural sources, i.e. not humans.
___
Ah, but what a difference that 4% anthropogenic source has made…giving us 40% more CO2 in the atmosphere in just a few hundred years…sort of like compounding interest.
More silliness – CO2 is a tiny fraction of overall atmosphere and if anthropogenic sources are 4% of all CO2 then the anthropogenic contribution to CO2 would comprise an almost unmeasurable portion of the atmosphere
Will someone please summarize the significance of this new analysis, so that we can all “eat the canary”. GK
220mph says:
September 11, 2011 at 3:36 pm
===================================================
220, excellent post, thank you
I have two questions and I never seem to get an answer….
In spite of higher CO2 levels, and all of it’s magical powers, why have temperatures this spike stayed way below all of the precious spikes?
http://t2.gstatic.com/images?q=tbn:ANd9GcQoNA4GG1XGKQnls15l7IEp9PMlujdC1n-fVhCcMup7ZZggiEU
Second, who in their right mind can look at that graph and put the “norma/0l” line way up there at the top? Even a two year old can see that is not normal.
The normal/0 line should be at least where -6C is…………..
That is the biggest scam……………., letting them define what normal is first, then based on that telling everyone it’s abby-normal……………..
220mph says:
September 11, 2011 at 3:45 pm
R. Gates says:
September 11, 2011 at 11:49 am
Gary Mount says:
September 11, 2011 at 10:17 am
You may also be interested to know that about 96% of all global emissions of CO2 come from natural sources, i.e. not humans.
___
Ah, but what a difference that 4% anthropogenic source has made…giving us 40% more CO2 in the atmosphere in just a few hundred years…sort of like compounding interest.
More silliness – CO2 is a tiny fraction of overall atmosphere and if anthropogenic sources are 4% of all CO2 then the anthropogenic contribution to CO2 would comprise an almost unmeasurable portion of the atmosphere
_____
It seems basic physics and chemistry of the atmosphere is where certain skeptics and “warmists” part ways, rather than the more complex and interesting things like cloud feedbacks and sensitivity.
The increase in CO2 in the atmosphere during the last few centuries over and above the normal 280 or so ppm during an interglacial is almost entirely based on human activities. To not get this basic science is rather sad.
RB says:
September 11, 2011 at 3:41 pm
R Gates:
“Ah, but what a difference that 4% anthropogenic source has made…giving us 40% more CO2 in the atmosphere in just a few hundred years…sort of like compounding interest.”
I’m no scientist but even I know that statement is utter drivel.
____
Again, it saddens me if you are from the U.S. as our schools are indeed failing us and it’s no wonder that the Chinese are now filing more patents each year than us and graduating more scientists and engineers.
220mph said:
“CO2 began rising again appx 3500 years ago, and has risen at appx the same rate as today for the last 2500 years. Despite that increase there has been NO statistically significant increase (or decrease) in temps over 12,000+/- years.”
____
Wow…just wow. This chart:
http://sitemaker.umich.edu/section3group3/files/icecores.jpg
And hundreds more easily prove you wrong…but again….wow.
R. Gates says:
September 11, 2011 at 5:17 pm
RB says:
September 11, 2011 at 3:41 pm
I’m no scientist but even I know that statement is utter drivel.
____
Again, it saddens me if you are from the U.S. as our schools are indeed failing us and it’s no wonder that the Chinese are now filing more patents each year than us and graduating more scientists and engineers.
====================================
Well, I have over 50 issued US patents and I know that statement is utter drivel too.
Do you have an advanced degree in Passive Aggressiveness, or are there courses you can attend to get like you ?? Just asking, so I can make sure my kids avoid them.
R. Gates says:
September 11, 2011 at 11:49 am
Ah, but what a difference that 4% anthropogenic source has made…giving us 40% more CO2 in the atmosphere in just a few hundred years…sort of like compounding interest.
====================================================================
Gates, this is a very confusing statement
First you say that only 4% is anthropogenic….
…then you attribute all of the rise in CO2 to anthropogenic sources
So in your mind, none of the increase in CO2 was natural, even though we know CO2 levels rise with temperature……
R Gates, I like this better:
http://wattsupwiththat.files.wordpress.com/2009/12/noaa_gisp2_icecore_anim3.gif
Puts the recent tiny tiny warming in perspective
G. Karst says:
September 11, 2011 at 3:58 pm
“Will someone please summarize the significance of this new analysis, so that we can all “eat the canary”. GK”
See: Bart @ur momisugly: September 11, 2011 at 2:40 am
[Reply] Bart, I’ve corrected a typo from +0.5 W/m^2 to +9.5W/m^2 – let me know if that’s right -TB-mod
Thanks, TB-mod.
I don’t understand it either. Pictures paint a thousands of words,..
http://en.wikipedia.org/wiki/Lissajous_curve
I think what Bart is saying that there already exist techniques for analysing data which plots in a scatter pattern. He has applied these techniques to dressler’s data and come up with something very interesting; negative feedback.
philincalifornia says:
September 11, 2011 at 5:37 pm
Well, I have over 50 issued US patents….
_____
Obviously none related to atmospheric chemistry if you can’t figure out that humans have been responsible for the rise in CO2 beyond the normal 280 ppm we might normally see during an interglacial…i.e. remove humans from the planet starting 10,000 years ago and we’d be seeing CO2 levels no higher than 280 ppm right now…and probably lower.
Latitude says:
September 11, 2011 at 5:39 pm
So in your mind, none of the increase in CO2 was natural, even though we know CO2 levels rise with temperature……
_____
There certainly is some rise in CO2 with a rise in temperature via outgassing and bioactivity, as this is part of the positive feedback process that is initiated with each Milankovitch warming phase, but most of that natural positive feedback rise had ended with the Holocene Optimum, and in fact, CO2 was trending slightly downward until the industrial revolution and the beginning of significant anthropogenic emission of CO2 (as well as other greenhouse gases by the way).
220mph says:
September 11, 2011 at 3:36 pm
(R. Gates’) sweeping generalization that we do not have to worry about a glacial period.
____
Earth to AGW skeptics…Coast is clear. No glacial period in your lifetime or your children’s children children children…etc. Milankovitch cycles don’t support it, and neither does the nearly 400 ppm of CO2.
R.Gates – let me help you understand that the concept of “greenhouse gas” is irrelevant. Here is a quite clear and concise post comparing Earth (CO2 is 0.04%) to Venus (CO2 is 96.5%).
http://theendofthemystery.blogspot.com/2010/11/venus-no-greenhouse-effect.html
R. Gates says:
September 11, 2011 at 6:30 pm
philincalifornia says:
September 11, 2011 at 5:37 pm
Well, I have over 50 issued US patents….
_____
Obviously none related to atmospheric chemistry …
===================================================
I think it’s already clear to everyone on here that what’s “obvious” to you has no basis in reality. To continue the trend, the last patent I filed was related to atmospheric CO2 chemistry, and I’m filing another this week. So shove that where the sun don’t shine.
Are you going to go back and show how the rise in CO2 levels is the same as compound interest, or are you going to continue to follow that stream of drivel with further branching streams of red herring-laden drivel, hoping that other readers won’t notice ??
What follows is a recap of three posts I made on on Dr. Spencer’s blog, concerning computation of the left-hand side of the main equation. You may recall that Dr. Spencer obtained 2.3 Wm^-2 and Dr. Dessler obtained 9 Wm^-2 for the LHS. The obvious differences between these papers were (a) Spencer used quarterly data, while Dessler used monthly data; (b) Spencer used a mixing layer depth of 25 meters while Dessler used a mixing layer depth of 100 meters.
In his blog, Dr. Spencer recommended use of Levitus when computing the LHS. Levitus appears to be the World Ocean Atlas (WOA) which is available online in updated form, here:
http://www.nodc.noaa.gov/OC5/WOA09/woa09data.html
I found that mixing layer depth has already been computed by Levitus on a global grid, and available from NOAA, here: http://www.nodc.noaa.gov/OC5/WOA94/mix.html
There are three criteria for ML in use: A) (most common definition) depth at which temp is .5 C lower than the surface; B) depth at which the density is .125 standard deviations greater than the surface; and C) depth at which the density is equal to what the density would be with a .5 C change. These three definitions give rather different results.
After downloading all the data and running global weighted averages (weight = cosine[latitude]), the global average mixing layer depth for each definition was:
A. 71.5 meters
B. 57.2 meters
C. 45.9 meters
These numbers fall neatly between the depths used by Spencer and Dessler.
Downloading quarterly data for temperature (objectively analyzed means) from WOA allows you to compute a weighted mean SST for the globe. The four weighted means thus computed were: JFM=18.293; AMJ=18.1672; JAS=18.128;OND=17.935, with a global annual mean of 18.130 C.
The four differences between quarters are then ,358, -.131, -.034, and -.193, with a standard deviation of those values being .247 C.
To compute heat capacity (and change thereof) I used the mean temp of 18.130 as a “before” value and a changed temp of 18.130+.247=18.377 as an “after” value. I computed density and heat capacity for both using a salinity of 35 g/kg and the equations of Sharqawy et.al. 2010. For a 1m x 1m x 25m column, I get mass=25634.58 kg (before), 25633.14 kg (after); HC=29854059 kJ (before), 29878463 kJ (after) for a quarterly change of 24404 kJ. The rate of change per quarter is therefore 2440384 J / 7889400 seconds = 3.1 Wm^-2. This is a bit higher than the 2.3 value given by Dr. Spencer. Note also that this value may be wrong; one could argue that we should be operating on a constant mass of water rather than a constant volume. Computing on that basis, the result would be 3.3 Wm^-2.
But note that this was computed using a 25m ML depth. Using the Levitus ML depths gives for the LHS of the equation energy change rates of (A) 8.9 (B) 7.1 and (C) 5.7 Wm^-2 respectively. In other words, Dr. Spencer’s 2.3 Wm^-2 seems too low.
Using monthly (rather than quarterly) WOA data, I find the global weighted-average SSTs by month: 18.176, 18.347, 18.357, 18.282, 18.147, 18.057, 18.134, 18.173, 18.078, 17.950, 17.871, 17.984 giving the same 18.13 average as in quarterly data.
This gives Delta-Ts of: .192, .171, .010, -.075, -.135, -.090, .077, .038, -.094, -.128, -.078, .113, and the standard deviation of these is .117°C. Already we notice a major difference: if the SST is changing by typically .117 C in a month, we might expect it to change by .117 x 3 = .35 C per quarter. But the actual quarterly change is .25, which means that monthly data is more variable than quarterly data. Not a surprise, but here it is quantified.
Now let’s repeat the same computations, but using Dr. Dessler’s assumptions. In this run I added a slight improvement: I also downloaded and used salinity data from WAO, which is a little less than the 35 I had been using (mean=34.586).
Using T=18.130 as the “before” temp and 18.130+.117=18.246 as “after”, I find a “before” density of 1025.0639, and for a column 1×1×100 meters a mass of 102506.4 kg, specific heat of 4.001219 KJ/kg/K and heat capacity of 119468525 KJ. “After” density is 1025.0369, specific heat is 4.001262, and heat capacity is 119514517 KJ. The change over time is therefore 45991.5 KJ in 2629800 seconds, for 17.5 Wm^-2.
Using the Levitus ML depths gives for the LHS of the equation energy change rates of (A) 12.5 (B) 10.0 and (C) 8.0 Wm^-2 respectively. In other words, Dr. Dessler’s use of 9 Wm^-2 seems about right, if used with a corrected ML depth, while Dr. Spencer’s LHS values are substantially too low.
Frankly, I’m new at these equations and perhaps I’ve made a mistake somewhere. If so, I hope Dr. Spencer (or someone else) will correct me.
I am afraid that neither side in this dispute is going to settle the question of whether man-made global warming is real or fictitious.
Correlation does not equal causation.
There was considerable warming of land temperatures world wide between 1900 and 1940 during a period when there was little industrial activity and many fewer cars were on the roads.
There was no correlation between CO2 and temperature during this 40 year period, This does not disprove AGW however, because a lack of correlation does not disprove a hypothesis either.
There is one thing we can say with absolute certainty.
THE SCIENCE IS NOT SETTLED!!
R. Gates says:
September 11, 2011 at 5:15 pm
It seems basic physics and chemistry of the atmosphere is where certain skeptics and “warmists” part ways, rather than the more complex and interesting things like cloud feedbacks and sensitivity. The increase in CO2 in the atmosphere during the last few centuries over and above the normal 280 or so ppm during an interglacial is almost entirely based on human activities. To not get this basic science is rather sad.
No, what’s unfortunately sad is ….
(A.) … to ignore that even 400ppm is a tiny fraction of the total greenhouse gases which comprise the atmosphere,
(B.) … to ignore that according to your own comment the anthorpogenic portion of that Co2 is 4% – or just 16ppm
(C.) … to ignore the long term historical record – recorded data, not models – which show we are well overdue for an inevitable descent into another glacial period
(D.) … to ignore, that despite increases in CO2 there has been no increase in temps for 12,000 or more years
(E.) … to ignore that ALL OF THE WARMIST claims are based on between 30 and 100 years of temperature data – completely ignoring the long term historical record which shows temps to have been STABLE – moving in a natural range – UP AND DOWN – over 12000 years, and last
(F.) … to attempt to claim that the recent decades or century of temperature history has a meaningful relation to climate cycles that operate on clearly defining 100,000+/- year scales
(G.) … to ignore that DESPITE the increase in CO2 there has been no increase in the long term temp history – to ignore that the recent temperature changes are well within the natural variability, up and down, of the last 12,000 year record
And that is really the question for the ages isn’t it? Why do warmists completely ignore these simple basics? Yes – temperatures did increase recently, and now have leveled. And that increase is both well within the natural range of temps during the last 12,000 or so years of STABLE temps, and also brings temps back to just over the median temp over that last 12,000 year period.
To me the biggest question in the “climate change” arena is why temps stopped rising – that they leveled out well below normal peaks seen in inter-glacial warm periods over last 400,000 years? And why they remained stable for the last 12,000 +/- years instead of peaking and sharply falling as in each of the inter-glacial warm peaks over last 400,000 years?
To me the serious question is what is keeping us from the severe glacial period we are long overdue for – and how can we keep doing it.
To me – if CO2 really has the magical properties attributed to it by the AGW crowd – then I say we probably should be trying to figure ho to prolong it, lest things get very, very cold very quick …
R. Gates says:
September 11, 2011 at 5:21 pm
220mph said:
“CO2 began rising again appx 3500 years ago, and has risen at appx the same rate as today for the last 2500 years. Despite that increase there has been NO statistically significant increase (or decrease) in temps over 12,000+/- years.”
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Wow…just wow. This chart:
http://sitemaker.umich.edu/section3group3/files/icecores.jpg
And hundreds more easily prove you wrong…but again….wow.
And you yet again show that you simply (and most of the warmist community – sadly including many scientists) don’t “get it” … the historical climate record is not 30 years, 100 years or even the 1000 years which you show. The climate cycle – glacial cold minimum to inter-glacial warm peak – is appx 100,000 to 125,000 years.
And when you look at the entire record you’ll find the picture looks quite different.
A better version of data set and short time frame in your picture:
http://www.koshland-science-museum.org/exhibitgcc/images/historical03.gif
And the same source showing the long term historical record:
http://www.koshland-science-museum.org/exhibitgcc/images/historical02.gif
Low and behold – in the 2nd graph – CO2 has been rising at app the same rate since the Younger Dryas – appx 12,000 years ago …
Wow indeed.
Bob B says:
September 11, 2011 at 6:12 pm
R Gates, I like this better:
http://wattsupwiththat.files.wordpress.com/2009/12/noaa_gisp2_icecore_anim3.gif
Puts the recent tiny tiny warming in perspective
Thanks you Bob … I shoulda just looked that up – it tells the story best of all …
R. Gates says:
September 11, 2011 at 6:43 pm
220mph says:
September 11, 2011 at 3:36 pm
(R. Gates’) sweeping generalization that we do not have to worry about a glacial period.
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Earth to AGW skeptics…Coast is clear. No glacial period in your lifetime or your children’s children children children…etc. Milankovitch cycles don’t support it, and neither does the nearly 400 ppm of CO2.
Funny – seems you have a real issue with comprehension … I believe we are at far more risk of dropping into the long overdue glacial cold period than an extended warming one.
What I DID say was from what I see in the historical record we are overdue for a inter-glacial warm peak – and the resultant share drop into a glacial cold period. I said if anything CO2 is possibly delaying us dropping into that inevitable glacial cold period.
At least make the effort to characterize what others say accurately and honestly
Truthseeker says:
September 11, 2011 at 6:58 pm
R.Gates – let me help you understand that the concept of “greenhouse gas” is irrelevant.
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Truthseeker,
If I had an identical Earth to ours…identical in every way, except take away all the greenhouse gases, I’d gladly let you live there…but just a hint…bring a very very very warm pair of long underwear.