I received a number of emails about the newly published Guemas et al (2013) paper titled “Retrospective prediction of the global warming slowdown in the past decade”. It’s paywalled. The abstract is here. It reads:
Despite a sustained production of anthropogenic greenhouse gases, the Earth’s mean near-surface temperature paused its rise during the 2000–2010 period1. To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer2, 3 has been proposed to overcompensate for the Earth’s heat storage. Contributions have also been suggested from the deep prolonged solar minimum4, the stratospheric water vapour5, the stratospheric6 and tropospheric aerosols7. However, a robust attribution of this warming slowdown has not been achievable up to now. Here we show successful retrospective predictions of this warming slowdown up to 5 years ahead, the analysis of which allows us to attribute the onset of this slowdown to an increase in ocean heat uptake. Sensitivity experiments accounting only for the external radiative forcings do not reproduce the slowdown. The top-of-atmosphere net energy input remained in the [0.5–1] W m−2 interval during the past decade, which is successfully captured by our predictions. Most of this excess energy was absorbed in the top 700 m of the ocean at the onset of the warming pause, 65% of it in the tropical Pacific and Atlantic oceans. Our results hence point at the key role of the ocean heat uptake in the recent warming slowdown. The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models, but also enhances the socio-economic relevance of operational decadal climate predictions.
Not too surprisingly ClimateProgress has a post New Study: When You Account For The Oceans, Global Warming Continues Apace about the paper.
The abstract suggests that the tropical Pacific and Atlantic Oceans are responsible for 65% of warming of global ocean heat content for the depths of 0-700 meters since 2000. However, the much-adjusted NODC ocean heat content data for the tropical Pacific (Figure 1) shows a decline in ocean heat content since 2000, and the ocean heat content for the Atlantic (Figure 2) has been flat since 2005.
Figure 1
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Figure 2
The abstract also mentions a new-found ability to predict slowdowns in warming. But the warming of tropical Pacific ocean heat content is dependent on the 3-year La Niña events of 1954-57, 1973-76 and 1998-01 and on the freakish 1995/96 La Niña, Figure 3. And the warming of sea surface temperatures for the Atlantic, Indian and West Pacific oceans, Figure 4, depends on strong El Niño events.
Figure 3
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Figure 4
CLOSING
Can Guemas et al (2013) can predict 3-year La Niñas and freakish La Niñas like the one in 1995/96? Can they predict strong El Niño events, like those in 1986/87/88, 1997/97 1997/98 and 2009/10? Both are unlikely—the specialized ENSO forecast models have difficulty projecting beyond the springtime predictability barrier every year.
FURTHER READING
For further information about the problems with ocean heat content data, refer to the post Is Ocean Heat Content Data All It’s Stacked Up to Be?
And for further information about the natural warming of the global oceans, see “The Manmade Global Warming Challenge.”
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Paul Homewood says:
April 9, 2013 at 3:36 am
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Paul
Since DWLWIR can only penetrate matters of microns (not millimeters) only the sun heats the oceans. It is probable that such DWLWIR as is absorbed by the oceans in the top few microns, if the DWLWIR has the ability to perform sensible work in the ocean environ, largely goes to drive evaporation.
However, the claim is that because of DWLWIR, the atmosphere above the oceans is warmer than it would otherwise be, such that the rate at which the oceans cool is less, thereby resulting in a warmer ocean. In otherwords because of the warmer atmosphere above the oceans, the oceans retain more of the warmth which has been generated from the absorption of solar energy.
One point to think about.
If the ocean has the ability to sequester this ‘energy’ to depth, why after approximately 4.5 billion years is the deep ocean only about 2 to 3 degC?
Lets face it, at some 320 W m^-2 the oceans have these past 4.5 billion years received an awful lot of DWLWIR back radiated energy, and yet it does not appear to have heated the ocean to any significant extent.
To the left of centre:
Your post at April 9, 2013 at 3:43 am is ridiculous.
It says in total
No!
Science says that a prediction of a model is compared to reality. Any difference between observed reality and the prediction is an indication of a flaw in the model. This is because a model is a representation of an understanding of reality.
Therefore, the difference between the model prediction and observed reality is a demonstration of a flaw in the modeled understanding of reality.
The flaw may be in
(a) the understanding
or
(b) how the model is constructed to represent that understanding
or
(c) both (a) and (b).
There are no other possibilities. And it is pure pseudoscience to imagine a not-measured effect and to feed that into the model to determine if it can be used to adjust the model prediction to agree with observed reality.
Such a practice is pseudoscience because there are an infinite number of not-measured effects which can be imagined, but none of them add to understanding of what was modeled. Addition of such an effect pretends the modelers have an understanding which they do not have.
The model failed its empirical test. Using “retrospective-prediction” of the kind reported by Guemas at al. is pure pseudoscience and cannot be thought “an entirely reasonable thing to do” except by pseudoscientists.
Richard
Actually postdict is the right term.
Yet another demonstration proving that ‘bullshit baffles brains’!
‘To the left of centre’ does make a valid point; but we can hardly be expected to trust *any* of the data used, on previous form; and hasn’t it already been proven that Mannian datasets can be used to prove *anything*?
Btw speaking of ‘form’, in racing parlance this kind of retrospective prediction is called ‘after-timing’ and attracts the utmost scorn and disbelief from serious punters
As a matter of semantics, I believe ‘Natural Climate Change Deniers’ should read ‘Deniers of Natural Climate Change’; the first phrase is capable of too many meanings ; )
Trenberth commenting on Guemas:
“”Global warming is continuing but it’s being manifested in somewhat different ways,” said Kevin Trenberth, of the U.S. National Center for Atmospheric Research. Warming can go, for instance, to the air, water, land or to melting ice and snow.
Warmth is spreading to ever deeper ocean levels, he said, adding that pauses in surface warming could last 15-20 years.”
http://www.reuters.com/article/2013/04/07/us-climate-oceans-idUSBRE93608420130407
So now the pause could last up to 20 years according to Trenberth! Didn’t the Team say that 16 years was the marker?
Given the wonderful NCAA Champianship game last night it is interesting how basketball illistrates a guiding principle of my life. Consider this sequence: 1-Coach calls time out, 2- play is drawn up in the huddle, 3-play resumes, 4- Defence does something unpredicted, 5-Chaos ensues. This sequence applies to football too.
My guiding principle is “Planning is figuring out what’s NOT going to happen. Obviously we can add the corolalary [sp?] “Predicting and forecasting for the climate scientist [?] is figuring out what you WISH will happen.” Retrospective predictions are figuring out what you WISH had happened.
ps: I played alot of basketball in my misspent youth.
The “science” of CAGW hangs by a thread and it must be rescued somehow. Quite apparent is the fact that the “science” is not “settled”, but rather than admit this, the alarmists now present us with a new paradigm… one sufficiently cryptic to prolong (or stifle) the debate a while longer. Maybe I am oversimplifying this, but if the oceans are warming, then at what point would a thermal equilibrium be established between the oceans and the atmosphere? My guess is “long enough” to continue the charade. There were two general possibilities to explain the current (and ongoing) lack of warming: a) the CO2 greenhouse gas theory needs just a wee bit of tweaking or b) the theory is flat-out wrong. The evidence (and Occam’s razor) points strongly to “b”, but that won’t get your grant funded and it does not justify increased government control of energy policy.
To “to left of center” I would ask why the previous models, back-tested as they surely should have been (by “retrospective prediction”), failed to account for this? And why should we now accept the new model(s) as being any more accurate?
“The only logical explanation is the sun.”
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I am an ignorant journalist, not a scientist. Even with a Fourier Transform, I couldn’t distinguish my ass from a hole in the ground. So I hope someone can enlighten me as to the role undersea volcanism plays in ocean heating. It would seem to be large, and unquantifiable: If it can’t be quantified, it can’t be modeled. And if it is large, the role of “climate change” in warming the oceans would seem to be pretty much moot. Please advise.
Okay, the abstract says
Bob’s graphs says that’s not the case. So the interesting thing will be to see how the authors determined that the missing heat is in the top 700 m.
Oh come on guys, “retrospective prediction” (or calibration, etc) doesn’t warrant the frothing around the mouth posters here have given it. If you don’t like term, suggest a better one, perhaps Bill Gray’s tests of new tropical storm forecast techniques has a good hint.
At the very least it doesn’t have the screwed up mathematical conotation that “4X less energy input” is the same as “75% less energy input”. Or is it 80% less enegy input? Just where is that 4 supposed to go, anyway?
“Predict” is the wrong word. “Hindcast” or the more clumsy “postdict” would be a more accurate term for the type of model testing you propose. The mockery results from the authors failing to recognize and acknowledge how silly their terminology sounds as well as the general failure of models to actually estimate future conditions accurately. Being able to tell you where you’ve been when you know where you’ve been is a really small accomplishment — absolutely required if you hope to predict where you’re going, but nothing to brag about.
Richie says: “So I hope someone can enlighten me as to the role undersea volcanism plays in ocean heating.”
Richie, you’re not the first to ask the question, and you will not be the last. I do recall papers and blog posts that attempted to quantify this and if memory serves, the impact was negligible.
When will the CAGW team ever admit that evidence such as this is showing us that anthropogenic CO2 is playing a very minor role in slowing down energy lost to space and that the cyclical processes of evaporation, condensation, freezing, and thawing are the rate controlling factors? Also, very likely, these processes are controlling the atmospheric concentrations of CO2 rather than CO2 controlling the rate of energy loss.
@- Louis Hooffstetter
”Do they have any empirical data that supports their proposal?”
Yes, the measured thermosteric component of sea level change, as well as the other data that shows OHC increasing down, and probably beyond 2000m
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
Note graph 6.
@- Paul Homewood
“I’m still waiting for someone to explain to me how the ocean can be significantly warmed either by the atmosphere, or downwelling radiation, which Bob confirms only penetrates a few mm below the surface.”
Downwelling thermal radiation is absorbed by CO2 and water vapor in the micrometer above the water surface. That is energy gain from a photon by an absorbing molecule which is then thermalised by collision with other air molecules in the vicinity and by collision with the water surface. A significant amount of the water vapor in the saturated layer immediately above the water surface is in continual exchange with the liquid water evaporating and condensing back into this surface at the nanoscale.
That enables a process of thermodynamic partition that transfers those Joules into the liquid ocean.
Science of Doom goes into more detail if you are really wanting to know more about this, and not just declaring your ignorance as somehow representative of what science actually knows. I think he makes the point that this surface effect can be regarded as a form of energy transport that limits the rate at which a liquid water surface can shed energy by evaporation.
http://scienceofdoom.com/category/ocean-physics/
Lots of people have picked up on the apparent absurdity of the phrase “retrospective prediction”, so I Googled(tm) it. I got “about 5,170” hits, many from articles about this paper, but also from other references which suggest the phrase is not unprecedented in the modeling discipline.
At a (very) course glance, it appears to mean model validation by successful hindcasting.
“To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer2, 3 has been proposed” … reminds me of the increasingly complex models of cogs and wheels they were forced to use to retain the earth as the centre of the solar system.
The only certainty, is that sooner or later even the maddest scientist will realise that it is far simpler to accept the simpler model: that the sun is the centre of the solar system, just as now the same troglodytes are being forced to accept that with all the extra wheels and cogs they are being forced onto their climate models … there are so many wheels … they are falling off the bandwagon.
wayne Job says: “Question 1 is english the first language of these people ?”
The lead author, Virginie Guemas…
http://www.lmd.jussieu.fr/~vguelmd/index_english.html
…is from the Climate Forecasting Unit (CFU) team of the Le Laboratoire de Météorologie Dynamique (LMD).
Hmmm. Lots of people jumping on the term “retrospective prediction”.
Seems to me it’s the same thing as a hindcast.
John Trigge (in Oz) says:
April 8, 2013 at 9:06 pm
Brilliant post! And you didn’t use the word ‘Orwellian’.
We need a game. What is analogous to a “retrospective forecast?”
Oh come on guys, “retrospective prediction” (or calibration, etc)
Ric
What follows calibration is test and validation. Don’t see that here. What they did is still inexcusable and not scientific.
The paper is really so over the top that it occurred to me that it would be a perfect April Fools Joke from Willis to the warmistas.
The warmers have a really good misdirection going on with this Ocean Heat Uptake spin. Its showing up everywhere now.
The followers feel better after seeing that there is warming continuing. They assume it was the amount forecast all the time but that is false. They are left with this mistaken impression and they are never corrected by the authors of pieces like this.
They are never told it is just a fraction of that forecast and a fraction of the total radiative forcing which is occuring. I’ll write this up when I have some free time but I don’t right now.
72% of the energy is missing or has been emitted back to space at an increased rate.
http://s17.postimg.org/y2qsxky8f/OHC_Missing_Energy_Dec2012.png
Should have seen this coming!
Bob Tisdale says:
April 9, 2013 at 6:08 am
“Hmmm. Lots of people jumping on the term “retrospective prediction”.
Seems to me it’s the same thing as a hindcast.”
What is annoying is that they retain the term ‘prediction’ in their newly minted phrase ‘retrospective prediction’. The standard practice is to distinguish “predictions into the past” from prediction or forecast by using a term such as ‘postdiction’ or ‘hindcast’. The distinction is important because prediction is about the future.
At best, ‘retrospective prediction’ is a confusing substitute for ‘prediction into the past’. The value of ‘prediction into the past’ is that it says right up front that this is not prediction.