Bishop Hill Zeke on Spencer and Dessler
Sep 16, 2011 Climate: Models There's an excellent post by Zeke Hausfather at Yale Climate Forum. It's written as a layman's explanation of the controversy.
I was struck by this bit:
Dessler begins quite clearly by pointing out how "the usual way to think about clouds in the climate system is that they are a feedback — as the climate warms, clouds change in response and either amplify (positive cloud feedback) or ameliorate (negative cloud feedback) the initial change."
He suggests that Spencer and Braswell's formulation — that clouds are both a cause of and feedback on climate change — is rather outside of current norms.
Doesn't this just sum up the problem with climatology - that new ideas, particularly from those outside the mainstream, are seen as a problem rather than a possible step forward?
Reader Comments (48)
Perhaps much of the reaction of the mainstream to SB11 is attributable to the non-scientific factors in play. Namely that, once again, what Spencer says about climate sensitivity goes way beyond what he publishes. He is over-playing his hand.
Zeke Hausfather's piece at YCF is a sober overview. He makes the central point about the SB11 brouhaha abundantly clear (emphasis added):
Bish, I read the Zeke post a couple of days ago, and that para did not imply to me the reading you put on it. Assuming Zeke is right, for Dessler to say that an approach is outside of current norms is a reasonable view. It doesn't mean it's right or wrong, but implies that it challenges current thinking and therefore needs to be a reasonably strong argument.
Relatively modest claim: that clouds are both a cause of and feedback on climate change
Yes, I can live with that.
Svensmark can live with that.
Dragic can live with that.
Pity not all climate scientists can accept this.
BBD wrote
"In the mean time, to paraphrase the late Carl Sagan, be skeptical of any extraordinary results that are claimed in the absence of extraordinary evidence."
Or in the case of Dessler and his statistically incompetent use of regressions with R2 values of 0.02, any scientist worthy of the title must utterly dismiss any claim of results in such absence of any evidence whatsoever.
Furthermore, science professionals should extremely suspicious of the validity of work of an entire field whose peers allow such drivel to be published - it really is beneath contempt.
SNTF
Strong words. But then this is all about rhetoric, not science (see quotes from ZH's piece in my earlier comment).
What you say is to ignore that SB11 made no case for a revision of the median estimate for climate sensitivity. It was simply misrepresented widely as having done so, starting with the UAH press release. Which is troubling.
As Emmanuel states:
Actually, Dessler 2011 is largely irrelevant here. What is problematic is the media misrepresentation of SB11. Unchecked by Spencer. And Spencer's ongoing narrative that CS is lower than the mainstream estimate which is not supported by his published work.
Although you'd never guess that from his books, blog, public speaking, interviews and supporters in the blogosphere.
This is all about creating an impression of uncertainty, not solid developments in atmospheric physics.
BBD, I think you are overstating the disconnect between SB11's content and the overarching conclusions drawn from it in the press. Of course it does not single-handedly prove low sensitivity. No single paper could do that, probably. And it was over-hyped. So were a lot of pro-consensus papers - Steig on the cover of Nature? So are a lot of papers in other fields. But the shape of the Delta T - Delta radiation lag correlation curves is suggestive that sensitivity in many models might be too high. The Bart et al. phase space analysis seems to confirm that view. Not a strong conclusion, but an interesting one. And the degree of rhetoric & assorted nastiness in the campaign against SB11 has been quite something to behold...
Jeremy Hervey
It's not so much me that may be overstating the disconnect between SB11 and the 'overarching conclusions' drawn from it elsewhere. It's only the sceptics who really think that Spencer has hit on a game-changer. No-one else does. Look again at the quotes from Zeke's piece in my first comment.
This should not be ignored by calmer heads such as yourself. It is of central importance.
Perhaps the strength of the reaction to Spencer might be related to the length of time that he has been making claims for low CS which are not supported by his published work.
Zeke H is an agenda pusher and his agenda is AGW. He is very clever at searching out strawmen and turning them into his reality. Spencer's paper is what it is and nothing more. The press, as with all climate papers, exagerate, deceive and mislead at every opportunity. For the AGW's they exagerate to push the agenda for the less than AGW papers they mislead to maligne the authors.
Simple really. Spencer and Dessler put their papers out there for examination, neither said that the documents were definitive.
"Zeke H is an agenda pusher and his agenda is AGW"
I agree. He's been posting on The Blackboard for years nothing but graphs that are supposed to indicate AGW. He's a Global Warming salesman. He's in some kind of enviornmental business enterprise.
http://www.linkedin.com/pub/zeke-hausfather/9/769/732
Andrew
BBD, do you accept that SB11 has some bearing on climate sensitivity, and that what evidence it provides is on the low sensitivity side? How about Dessler's 2010 Science paper - do you think that the weak (even weaker?) evidence in that work, in favour of high sensitivity, got over-hyped by consensus people?
Jeremy Harvey
Not really, and not convincingly, to answer both your questions.
There is a large body of work that attempts to improve the estimated value for both transient and equilibrium CS. If you are genuinely interested, see (as a small sample only): Knutti et al. (2006), Annan & Hargreaves (2006), Tung & Camp (2007) and Hansen et al. (2008).
I'll take a risk and make a little prediction that can be falsified: SB11 will ultimately prove to be a side-track. The currently accepted estimate of ~3C per doubling is not cast in doubt by SB11, and will not be overturned by any future work by Spencer (or indeed Lindzen).
You can all save this and taunt me with it should it eventually be proved wrong. I won't care because I'll be too busy getting drunker than I've ever been in my life. Because this would mean that it's all been a terrible 'blunder' and there's nothing to worry about after all.
"it's all been a terrible 'blunder'"
BBD,
What event(s) should we look for so we can discern whether it's been a blunder ot a success? What will the landmarks be?
Andrew
BBD - why would you want to get so drunk if there's nothing to worry about? Some of us think that already, and we're pretty sober most of the time (although I often think that our legislators must be on something).
BA
While CO2 ppmv continues to rise, we'd need to see:
- a sustained fall in GATA (>15 y)
- a reversal of the currently rising trend in DLR flux measured at the surface
- satellite MR observations must show a reversal of the currently rising trend in precipitable water vapour over the major ocean basins
BBD,
As someone 15 years out of grad school who went into industry rather than science, I follow the climate change debate more as an outsider than as a member of the reseach and academic community. I try reading websites on both sides of the debate, but I have to be honest in saying that any doubts I may have (which are mostly centered around all of the predictions of calamity and doom awaiting us due to a warming climate) tend to be reinforced when I repeatedly hear statements that the debate is over. Such a statement sets off alarm bells for me, particularly when it is in regard to the topic of science.
So along comes SB11 and a significant part of the criticism I am reading about it has to do with the press release and media coverage. It being a day after Al Gore's 24 hr telethon, I doubt either the p-k quotient (pot-kettle) or level or irony could get any higher. 15 years ago it was my understanding that our understanding of clouds, the role they played on climate and the ability to accurately model them was poor at best. My impression today is that this is still largely true. The biggest takeaway I have from SB11 is exactly that - until we have a better understanding of clouds, we should maintain a healthy dose of Missouri "Show me" when it comes to predicted outcomes based on modelling.
BBD, I think your answer proves my point: SB11 *is* in part relevant to the question of sensitivity, and it *does* provide some evidence for low sensitivity. "Not really" means "yes a little bit"... I don't for a moment find it fully convincing, and do not discount the evidence for higher sensitivity. But the attempt by Trenberth, Wagner et al to present Spencer as having made a completely illegitimate contribution seems unfair to me. Wrong, maybe. Dishonest, I don't think so.
BBD,
Perhaps you could give me some quantifiable thresholds instead of the subjective:
"sustained"
"reversal"
That way we have some stable goalposts to kick through and we can crack those coldies. ;)
Andrew
BA
I said >15 y of sustained decrease in GATA, so let's say a fall of 0.2C. Reversal needs no qualification. Current trends are positive: they must turn negative and stay that way for >15 y.
Jeremy Harvey
If I may differ. SB11 really doesn't provide evidence for a low climate sensitivity. That's going too far. Also, it has to be considered in the context of the body of work pointing to an equilibrium CS of about 3C. If you look at the papers I picked out, you get a feel for the spread of methodologies that have been brought to bear on exploring the sensitivity problem. Collectively (and as I said, this is just a small sample), the effect is persuasive. SB11 is very much less so, when considered in this context.
If you are going to argue for a low CS, you have to answer The Question ;-)
Low CS requires that the climate system sheds energy efficiently to space following an increase in RF. By definition, a low sensitivity climate system cannot easily warm, because energy cannot accumulate within it.
So, how do we explain the transition from glacial to interglacial under sustained but only moderate increase in RF (DSW) from Milankovitch forcing?
Now I cannot answer that question unless the value for CS is at least 3C. Can you?
BBD,
Okkaayyyyy.
Which data product from which institution will be providing our Official Blunder or Boon numbers?
Andrew
BA
This is pointless, but to humour you, let's say that we'll look at RSS/MSU and UAH for TLT, HadCRUT and GISTEMP for surface GAT
Satellite MR observations of precipitable WV are likely to come via NASA. Surface measurement of DLR - who knows at this stage? So long as it's observational data, published in a mainstream journal and not subject to mainstream controversy, it will have to suffice.
Dream on, btw.
BBW:
"So, how do we explain the transition from glacial to interglacial under sustained but only moderate increase in RF (DSW) from Milankovitch forcing? Now I cannot answer that question unless the value for CS is at least 3C. Can you?"
Whoever said that climate sensitivity had to remain a constant under all conditions? Seriously... stew on that for a while.
Climate sensitivity is the sum total of ALL forcings and feedbacks acting on the climate system. Some factors operate more strongly over certain temperature ranges than others
For example, ice albedo feedback can only exist where there is a marginal melt/freeze zone... the magnitude of this feedback would be proportional to the surface area within the transition zone and the incidence of sunlight on that area, both of which would be substantially different in a glacial period than in an interglacial period, as the leading-edge of ice covers a greater surface area at lower latitudes.
Similar constraints would apply to other forcings and feedbacks.
So, how do I explain the transition from glacial to inter-glacial conditions with CS <3C? Easy... stronger feedbacks and higher sensitivity over a narrow range of temperatures, lower sensitivity above and below that range, resulting in a relentless flip-flopping between two stable equilibrium states... glacial, and interglacial.
Sorry, my comment above should have been addressed to "BBD", not "BBW".
BBD,
"While CO2 ppmv continues to rise, we'd need to see:
- a sustained fall in GATA (>15 y) "
Your criterion is telling. Why on earth would a sustained fall in GATA in the face of continued CO2 ppm rise be necessary to disprove CAGW?
Why would not a sustained flat GATA in the face of a (larger than anticipated) rise in CO2 ppm, or a rising trend lower than that predicted by the allegedly explanatory (and allegedly predictive) models, be sufficient? The answer, of course, is because we have that.
There is obviously a physical reason for Spenser and Braswell's finding that there was a reduction in planetary cloud cover that correlates with the warming periods. All researchers are in agreement that a reduction in planetary cloud cover will cause warming. What you are missing are a series of published papers discussing the reduction in planetary cloud cover (Spenser and Braswell's paper one of a series of published papers concerning the fact that planetary warming and cooling correlates with changes in planetary cloud cover) and a relate set of papers that discussion the underlying mechanisms for what is causing the change in planetary cloud cover.
What you are also missing in this discussion is the series of published papers that discuss past warmings followed by cooling and abrupt cooling that is recorded in the paleo climate proxy data. There is correlation of cosmogenic isotope changes that correlates with past climate change periods, as well as the current climate change period. There are at least three different mechanisms by which solar magnetic cycle changes modulates planetary climate. (i.e. The mechanism is more complicate that a simple increase or decrease in GCR causes an increase or decrease in planetary clouds.)
The reduction in planetary clouds that correlates with the late 20th century warming has at a latitude of 40 degree to 60 degree.
There is a second mechanism by which solar activity changes modulates planetary cloud cover. Solar wind bursts caused by coronal holes create a space charge difference in the ionosphere which removes cloud forming ions. The next paper provides data that shows there is close correlation with geomagnetic field changes (ak) which are caused by the solar wind burst and planetary temperature. The next review paper by Tinsley and Yu summaries the data that supports the assertion that solar activity changes modulates planetary cloud cover and shows how that mechanism is hypothesized to work.
See section 5a) Modulation of the global circuit in this review paper, by solar wind burst and the process electroscavenging where by increases in the global electric circuit remove cloud forming ions.
The same review paper summarizes the data that does show correlation between low level clouds and GCR.
http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf
http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf
http://www.agu.org/pubs/crossref/2009/2009JA014342.shtml
Rejecting the possibility that clouds can be a forcing agent in effect rules out any physical driver that would MAKE them a forcing agent; e.g., Svensmark's cosmic ray hypothesis, recently butressed by CERN findings. It is no accident that rejection of significant a solar variability effect on climate AND the presumption that clouds cannot force go together. If it is wrong, climate alarmism is out of business, and with it the grant money and appointments to national academies and all the rest of it.
If I ever come across a thread which has not degenerated to an examination of the 'wood for trees' graphs.
Zeke is a clever agenda-pusher. I like that statement.
"published in a mainstream journal and not subject to mainstream controversy"
How scientific.
"who knows at this stage?"
Screeeeeeeech. Crash. Burn. ;)
Andrew
"In the mean time, to paraphrase the late Carl Sagan, be skeptical of any extraordinary results that are claimed in the absence of extraordinary evidence."
This statement is just piffle, isn't it? It automatically rules out any advance that is caused by simply finding a different point of view.
...just what evidence did Einstein have?
but then again...just how much evidence did Wallace and Darwin have before they dared to publish!
cannot resist the wiki page on Arrhenius:
"Arrhenius estimated that halving of CO2 would decrease temperatures by 4–5 °C (Celsius) and a doubling of CO2 would cause a temperature rise of 5–6 °C.[5] In his 1906 publication, Arrhenius adjusted the value downwards to 1.6 °C (including water vapour feedback: 2.1 °C). Recent (2007) estimates from IPCC say this value (the Climate sensitivity) is likely to be between 2 and 4.5 °C. Arrhenius expected CO2 levels to rise at a rate given by emissions in his time. Since then, industrial carbon dioxide levels have risen at a much faster rate: Arrhenius expected CO2 doubling to take about 3000 years; it is now estimated in most scenarios to take about a century.
[edit] Racial biology
Svante Arrhenius was one of several leading Swedish scientists actively engaged in the process leading to the creation in 1922 of The State Institute for Racial Biology in Uppsala, Sweden, which had originally been proposed as a Nobel Institute. Arrhenius was a member of the institute's board, as he had been in The Swedish Society for Racial Hygiene (Eugenics), founded in 1909.[6]"
BBD - he subscribed to eugenicism...should you not feel obliged to disown him? (irony tag)
and I am still trying to find experimental confirmation of his 2 widely divergent estimates! This frokm 100n years ago. The fact that it is hard to find experimental confirmation of A's findings is, maybe, a travesty?
Russ R.
Good points. Climate sensitivity is different under glacial and interglacial conditions. But it is high enough during both to allow the transition between them, or such transitions could not occur.
From your example: marginal melt/freeze zones at the edge of the NH ice sheet modulate ice-albedo feedback. But in order for any change to occur, the climate must be sufficiently sensitive for relatively small changes in forcing (DSW from Milankovitch) to initiate melting/freezing in the marginal zones.
This is then substantially amplified by ice-albedo feedback. So climate is highly sensitive to small changes in DSW during glacials. Agreed. Because the climate is sensitive to small changes in RF.
The same holds true during interglacials. As it must, unless the laws of physics alter during transitions.
"extraordinary evidence" I mean, what the ... is that? What about someone who produces evidence against a consensus, which was formed in the first place, due to a lack such evidence?
Shub
;-)
Watch out, or I shall start posting links to graphs!
Scientific consensus emerges from a broad confluence of results. Not one or two questionable papers, eg MBH98/99 and SB11.
BBD
Can clouds be a forcing?
given that water vapour appears on both sides of the energy balance ( as a GHG and in clouds) it seems a no brainer to me that getting to the point where we have a functional model of the cloud effects and their balance is fundamental to the issue at hand. We clearly do not have that at present and the science cannot therefore be "settled". Its a bit like being cast out from Paradise, the only thing we can be absolutley sure of now is that we do not now live in Paradise and that everything else is just the consequent details.
We do not have a functional climate model and the rest is just the details.
Looking at this whole AGW thing I am increasingly reminded of the Lindy Chamberlain case in Australia ( see movie "Evil Angels" starring Merryl Streep ) . Her infant dead, she had the media pack shove cameras in her face and grill her " Did you murder your baby?". Her shocked expression "condemned" her in the kangaroo court of the public arena and she was eventually convicted under the law, largely thanks to some "science" that indicated a positive test for foetal blood. The same test later was shown to test positive for rust inhibitor and since the "sample" came from the floor of a car ..... The "science" was just an effing joke with hindsight, simplistic junk leaping to a conclusion with horrific consequences for the whole Chamberlain family and to the ( rightful) humiliation of the police, prosecutors etc. Years and a Royal Commission later she was freed from prison, apologised to and paid millions in compensation. Her infant's jump suit subsequently turned up, shredded and with dingo saliva all over it. A national embarrassment frankly.
Just food for thought, but can you imagine the fallout if/when this whole AGW thing is finally settled as a false alarm, an overblown, over reaction to a minor quantum of AGW about which it is impractical to try to revert or re-engineer. The scientists, lobbyist's and nations who bang on the most about AGW DOOM will be the rest of the world's village idiots.
But what is the QUALITY of those "results"? Can we not judge them against the best comprehensive measurements? (eg, MSU temps, modern SST & OHC, sea level measurements) And cannot we therefore ask "where is the extraordinary evidence"?
How is 1.4C linear century trend evidence of an Enhanced Greenhouse Effect? For me, this defines the Warmist / Denier, or Believer / Skeptic divide.
There is no "weight of the evidence" at play here, since so much of the 'evidence' is assumed or even built into the models, that now Trenberth (at Remote Sensing, SB11 Comment) says cannot be assayed until after 20 years or more....?
THAT'S simply not 'extraordinary' evidence, if it is even 'evidence'!
BBD
It is not clear to me why you are so concerned that the earth may be warming, just a little bit over a longish period.
As somebody said recently, a change from an average 288 degrees Kelvin to 288.8 degrees K over 100 years, given the chaotic nature of climate and the uncertaities of measurement, seems to be as close as dammit to "no change".
I have never seen a good summary of the net benefits of a small increase in global temperature compared with the net costs or dis-benefits of the same.
I read plenty about all the shock horror possible future dis-benefits, but none of the possible future benefits.
What I read is so one sided as to be laughable and only fit for the garbage can.
Now you seem to be a real scientist.
Please refer me to a good even handed summary of the possible effects, good and bad, and I'll begin to listen.
Until that it is all smoke and mirrors, all nighmare fairy tales told in a dark cavern on a bleak wintery night, with the wind howling all around us and nothing unusual happening.
BBD
I should have made clear that when I talked about rising temperature I was talking about evidence.
That means past temperature change, not model projections, forecasts or whatever of the future, which as you know are merely the output of the assumptions input.
Forecasting, particularly forecasting the future is very difficult.
I write this with more than just a tiny bit of knowledge of the art of developing both small and very large computer models.
Joe D'Aleo has a lot of fascinating charts up on Arctic cyclic patterns.
I'd call this one alternative explanatory perspective to AGW.
@Aussie Dan
+10!
An excellent question. And one that I am pretty convinced you will never get an answer to.
I have never been convinced that the absolutely optimum temperature for the Earth is exactly 288.00K and that any deviation by +/- a few percent will cause the End of the World as we know it. Nor that all effects of such a change necessarily bring disaster in their wake.....
If Zeke Hausfather wrote an article every time this happened in the climate change field, Yale Climate Forum would be filled with articles only written by Zeke Hausfather.
Re BBD
"be skeptical of any extraordinary results that are claimed in the absence of extraordinary evidence."
Yes, but wouldn't that in fact be a requirement for those who say that we shall spend trillions of dollars on global warming: to back it up with extraordinary evidence?
Yet what we have is not very much in terms of evidence at all. The IPCC relies heavily (almost exclusively) on models; models that on numerous accounts have been shown not to be valid; models that no modeller nor IPCC have validated.
The actual physical evidence point rather in the other direction (hot spots missing and thus indicating little positive water vapour feedback; the missing heat; the lower temperature than forecasted; the proof that cosmic rays alter droplets in the atmosphere, from Harrison 2006 to more recent laboratory experiments).
BBD, interesting range of studies. Knutti uses models, worthless as the models are tuned to a certain sensitivity, Annan, negative feeddback is within the 95% confidence bounds, hence entirely in reasonable accord with Spencer as a possibility, Tung uses the interannual variation, not so sure on this but possibly beset by much larger uncertainties than evaluated in the paper, especially around tmperature records. The last paper quoted, Hansen et al is utterly worthless as Hansen is scientifically unreliable (he's purely a politician these days and prepares his papers on that basis) and I wouldn't take anything he publishes as honestly prepared. The paleo evidence he uses is also unsound, and the paper would not survive a proper peer review.
Anything else you'd like to raise, so far you're batting a possible 1 from 4.
I don't think Spenser's paper is necessary all it's cracked up to be, but it is far more interesting for the barrage of dishonesty that the warmenist repsonse represents. Imagine Trenberth demanding methods and data ! Imagine, the only time in his climatological life he's ever thought that necessary. In fact I'd go further and say that he's both implicitly and explicitly supported NOT making data and methods available if he agrees with the results (and probably knows that it is methodologically dubious). He's a person without credible scientific honesty.
Dessler begins quite clearly by pointing out how "the usual way to think about clouds in the climate system is that they are a feedback — as the climate warms, clouds change in response and either amplify (positive cloud feedback) or ameliorate (negative cloud feedback) the initial change."
He suggests that Spencer and Braswell's formulation — that clouds are both a cause of and feedback on climate change — is rather outside of current norms.
--------------------------------
Please read the above that was copied from the leading post. Read it carefully. There is little difference in what was claimed by either.
Now ask yourselves, what do clouds do? Go have a beer and think about it.