Bishop Hill NIPCC interim report 2011
Aug 30, 2011 
The Heartland Institute's NIPCC interim report has just been published - see here. This is a summary of the new scientific literature since 2009.
I've taken a glance through the paleoclimate bits and it appears to have been put together in a very professional manner. I was blissfully unaware of just how much evidence has been emerging for the existence of a MWP in the world outside Europe.
If I had a criticism based on what I have read, I would say it's over the authors' tendency to slip into editorial mode - discussion of Mann being engaged in "subterfuge" looks out of place in a scientific report.
Lots of people are not going to like the report of course. Peter Gleick, the president of the Pacific Institute, tweets that the report makes him sick and refuses to link to it. Barry Woods and I have politely asked which bits in particular he is concerned with and he has told us that he doesn't need to do this when someone is arguing that the Earth is flat.
Reader Comments (144)
BBD, I has looked at Figure 3 and associated text before I made my comment, so I guess we'll just have to agree to disagree on what it implies. I also realise that Hansen's work does not use models but that wasn't the context for my comment, so your posting of the Hansen quote was irrelevant to that particular point.
I'd still like to know your thoughts on the implications of Hansen's conclusions but, given the way you're responding to comments, I'm not going to press the point... I think we've gone as far as we can on this one.
Shub
Your argument is, as usual, a bit muddled.
Now we've got the definition straight, we know we are talking about sensitivity to a change in RF, itself a combination of DSW and DLR. In the past, DSW has changed (Milankovitch; quite possibly MWP); in the present it appears to be substantially DLR (increasingly evident in GAT from the mid-1970s).
There's no clear evidence of significant forcings other than CO2 in play over this period. Nothing sufficient to explain the warming since the mid-1970s.
There's also no explanation forthcoming as to why our understanding of the physical properties of CO2 is incorrect.
What to think?
Dave Salt
Indeed.
Dear BBD,
'Sensitivity' of the climate system is not merely something to be defined and filed away. It is a problem in and of itself. How the system might 'respond' - from which we infer 'sensitivity', may be completely different for the different factors that cause such responses.
So, per your argument now, an unknown factor caused a significant amount of warming in the recent past. If the climate system possesses such high sensitivities to unknown factors, then, conversely, the influence of CO2 is being overstated for the present state.
'Sensitivity' based on a radiative physics framework, to a factor (CO2) that participates a chemico-biological entity (as opposed to being a purely physical factor). Yeah, I am totally convinced by these IPCC'ish arguments.
not banned
Your points:
1) How is CO2 expected to operate?
Oh come on.
2) Could anything else?
Yes, but we'd see it. And we don't.
3) If temperature stops rising, does this mean additional energy has stopped accumulating?
I'm assuming you mean atmospheric temperature. This is interesting. Why the pause? Don't know, but I shall be keeping an eye on OHC reconstructions. Things in that field can, as they say, only get better.
4) Are you talking about correlation?
Umm
5) How would you define criteria to decide this?
Too vague.
Shub
You are waffling.
BBD,
It is your argument about the MWP that is complete nonsense. They wrote a whole report - on the basis that it is to CO2 alone that the climate system responds with an 'unprecendented' rate of change and a magnitude of change. You now want to throw all that out - guess whose arguments you are going against, first.
BBD -
Is there any reason to believe that sensitivity in a glacial period is the same as in the interglacial?
Please Harold, don't ask those kinds of questions.
Sensitivity = change in degrees Celsius, per watts per square meter,°C/Wm-2
As it is clear from the equation above, the present state of the climate system, is not a part of the equation.
I wonder how strong the tilt of the earth must be, to counteract all the outgassed CO2 - the more of which is invariably present at the peak of an interglacial. An entity that can counteract the temperature-changing effect of CO2 by a change in temperature...can you imagine that?!
Ah, but wrong about what?
Lindzen believes passionately that it is important to try to measure sensitivity here and now. He seems to think that's crucial to the scientific method. You finally seem to be agreeing with him. That's a relief.
Lindzen believes that estimates of sensitivity from models and from sparse paleo data are far less reliable, and thus far less important, than measuring sensitivity in the here and now.
You haven't made clear whether you agree with him on this point. But I never tire of asking.
Lindzen, as I said originally, is very honest about the challenges of measuring sensitivity now. It's hard - but nothing like as hard as coming up with the right answer from paleo data or software models, where the chances are close to zero. Do you agree with Lindzen that measuring sensitivity from modern data is challenging? Or is it dead easy - and the answer comes out as around 3 deg C with very little uncertainty at all?
Talking of which, I noticed that 'BBD' wrote nothing when the good Bishop reported in July on Nic Lewis's exposure of how IPCC WG1 had treated Forster & Gregory statistically - the Bend it by Bayes episode. This was the one study of sensitivity in AR4 based on real world data and it had to be bent to not look like a complete outlier on the relevant graph with estimates from models. What did you make of Lewis's critique? Do you have any criticisms at all these days of the 'consensus' treatment of sensitivity?
Thanks in advance. (I realise by now that it may be years in advance. But I'm a patient man.)
HaroldW
Yes. Unless the laws of physics have changed, then climate sensitivity to changing RF is going to be the same over the long term.
shub
This is completely incomprehensible. You will confuse other posters, notably HaroldW. Not helpful at all. The opposite, in fact.
Richard Drake
Lindzen is largely discredited. Like it or not, that's how it is.
His Iris hypothesis did not pan out and L&C (2009) was a mess.
I can only suggest that you go back to Knutti & Hegerl (2008) and the recent Hansen & Sato paper and read them carefully.
I was away when the Forster & Gregory fuss happened, but IIRC, did not both authors approve the SOD? Did they not?
Unnecessary.
No, you haven't answered even one of my questions - and they are vital ones. You know that you haven't. You are playing games.
I didn't ask if Lindzen was discredited - because that word implies a body of experts who are trusted and in climate we don't have that luxury. I don't think this thread is the right place for a discussion of Lindzen's various papers (with Lindzen and Choi 2011 responding to and in some cases correcting for some of the criticisms that have been raised). But given your claim about the MWP and sensitivity I thought it was well worth revisiting which avenue of research and analysis for estimating sensitivity was true science:
1. paleo
2. models
3. modern data
Lindzen believes 3. is the only scientific way and I agree. What bothers me most is that this belief in itself seems to mark him as 'largely discredited'. But you can still put me right on that, as far as your own views are concerned. But I'm not holding my breath. I'm a patient man.
No Richard. The game-playing started well upthread, with your first dodge of this question:
How does a cold world with a low climate sensitivity accumulate enough energy in its climate system to exit a glacial?
You still haven't answered it and I am weary of your obfuscation and misdirections.
If you did as I suggested, and re-read K&H and H&S you would see your straw man for what it is.
Climate science uses all avenues to constrain a value for climate sensitivity. Models, modern observations, paleo data - everything. Your claim that Lindzen is a voice in the wilderness crying for modern data is simply wrong. And coincidentally tactically misleading. See Knutti & Hegerl.
And no more nonsense about me playing games.
I never dodged the question. I said that I didn't know, and I said it at the first opportunity. If you really know - or Hansen knows, or Knutti & Hegerl know - then climate science is at a level that is truly astounding and inspiring. The Nobel Prizes should be be flowing every single year. Presumably those maths prizes concerning a solution to Navier-Stokes and much else in all of earth science. And we should be enjoying every year, in every region, the fruits of accurate prediction of the climate system. That this has all happened and I have missed it is I admit a very black mark against me.
Back to the real world as I understand it. Inquiring of real data today is the only possible way to get a grip on sensitivity. The contortions in AR4 with Forster & Gregory were an abuse of the real world to which the authors rightly looked for answers. The fact that they did not finally register a public objection to this treatment (and as far as I know that's true) says much more about the surrounding culture than the quality of AR4 WG1. For anyone objective this one episode shows how little official climate science cares about testing its hypothesis of high sensitivity against modern data. I recommend the Climate Etc. threads concerned, particularly what Nic Lewis himself contributes.
I don't accept the cumulative argument for high sensitivity, from the three different sources. This isn't a trial with three equally credible witnesses. Only one is at the scene of the crime and is alive to tell us the story. I am interested only in what the real world is telling us in the modern era. That is hard enough to work out, as Lindzen has said. I once again recommend his latest presentation for the scientifically literate.
BBD
Can I turn that question on its head and ask: How does a warm world with a high climate sensitivity disperse enough energy from its climate system to enter a glacial?You know I'm an ignoramus on these things, BBD, but either the sensitivity is low or it is high OR it may possibly vary depending on circumstances. Or, from my limited reading, entering and exiting ice ages is more to do with the state of the earth's orbit round the sun in which case "sensitivity" is not really a factor, certainly not "sensitivity" as it appears to be defined these days which is "how much the climate responds to CO2 concentrations". apparently to the exclusion of all else.
It's telling us + 3C per doubling for fast feedbacks. As you would know, if you troubled to read the literature instead of limiting yourself to Lindzen's (unpublished) pronouncements.
The simple question about climate sensitivity which you dodge by feigned agnosticism can clearly only be resolved by assuming a higher climate sensitivity, which Hansen & Sato find as... 3C.
I have to say this. Scepticism means weighing all the evidence, not deciding in advance which little bit you like and wilfully ignoring everything else.
Mike
Very easily. A higher sensitivity means that reducing RF (here DSW, per Milankovitch forcing) has a strong cooling effect. Once a positive ice albedo feedback is established as the growing NH ice sheet increases the amount of DSW reflected back into space, cooling intensifies and a full glacial begins.
Research Milankovitch cycles, and check upthread for a correct definition of climate sensitivity which will resolve and dispel this confusion.
Have you ever considered the advantages of researching climate science before deciding to be a 'sceptic' by the way? It would seem only reasonable.
once more - can someone tell me if sensitivity is a constant?
So far I'm stuck at climate politics and from reading this thread I'm not sure which bit of 'climate science' would be correct. There seem to be so many different opinions.
Still, I'll keep trying. But my natural default is scepticism (comes of being an old-fashioned journalist). When I find some convincing empirical evidence I'll give it all the respect it deserves.
Mike
I was told - very sharply - about a year ago, that unless I had achieved a good working understanding of climate science, I should remain mute on the subject and simply pay attention. It was good advice. I listen better and learn more when I am not talking.
That is not scepticism. It is prior commitment to the belief that climate science is in error over CO2.
BBD: Not everything claimed as evidence is admissable as evidence. I have nowhere here assumed that Lindzen is correct in his current estimate of sensitivity; what I have done is to recommend his latest presentation. I have read others and will continue to do so. But I'm only interested in real evidence. Unprovable speculations about the distant past aren't evidence, any more than recent speculations (about clouds and aerosols, for example) embodied in GCMs. You think these are evidence and are on a equal footing with the kind of inquiries made by Lindzen. That's the reason I don't think the conversation is worth the candle. I'm gald to reach clarity on that point.
genuinely curious, BBD, in how you would respond to Lubos Motl/his guest poster
"http://motls.blogspot.com/2011/08/nir-shaviv-cloud-is-clearing.html#more"
Richard
You are an intelligent man. You know that for much of this exchange you have been avoiding addressing the implications behind a certain question.
That's the reason this conversation has been worth every minute I have devoted to it.
Having looked at L&C (2009) and critiques thereof, I can say with confidence that:
- you are mistaken to treat Lindzen as the purveyor of 'real evidence'
- you are mistaken to dismiss essentially everything else (GCMs; paleoclimate studies such as H&S 2011) as worthless
- this is clear evidence of severe bias on your part
- you confirm this by dismissing work such as H&S (2011) and presumably all other studies of the LGM and previous interglacial/glacial transitions as 'unprovable speculations about the distant past'
diogenes
A dispassionate look at the evidence strongly suggests that although the cosmic ray effect is real, its influence on climate is very small.
See Sloan & Wolfendale (2011). From the abstract, emphasis added:
Full text here: http://arxiv.org/abs/1108.1047
BBD,
Since you are so confused etc,
If 'sensitivity' is the response of the climate system to a change in radiative forcing, how can a decrease in one forcing factor, overwhelm the positive forcing of another?
In other words, in your simplistic linear sensitivity-based framework, how can temperature itself function as a forcing?
Shub
Are you talking about exiting interglacials? In other words decreased DSW (end peak Milankovitch forcing) vs DLR from ca 280ppmv CO2?
If so, the answer is simply time. DSW powers the show. Reduce it and after a while, DLR from GHGs falls. Give it long enough, and DSW becomes the decisive forcing and once the NH ice sheet starts to grow, ice-albedo feedback takes over.
BBD,
I don't want literal explanations from you.
My question is simple enough. How can temperature be a 'forcing'? How can the same term appear on both sides of an equation?
Please show this equation.
Also, please be specific: what about my literal explanation do you disagree with, and why?
Whoever wrote that I judge as dishonest or of poor judgment so it doesn't warm any cockles. I have no interest in knowing more, without the courtesy of the name by which they are known in real life declared publicly. Without that I have no relationship with this person to worry about. But the subject matter here is important and they have certainly proved adept at avoiding key questions and twisting the rest.
What is and isn't evidence for high or low sensitivity is of fundamental importance. I stick firmly to the assessment I reached looking into this around seven years ago: real world data now, in an age we have satellites and sensors of so many kinds, is a thousand times more important than the illusions of software models or post hoc guesses about paleo-climate. Not that estimation of sensitivity is easy even then. But, if one has limited time and a decent grasp of the scientific method, that's the only area it makes sense to delve in. That's not bias; that's common sense. Without that clarity, one becomes easy prey to propaganda from the unscrupulous, using the staggering complexity of the past and of software models to bamboozle the reader out of their better judgment.
That's not to say that study of paleo-climate events like the LGM is worthless. It's a wonderful thing to undertake, when done with scientific integrity. It's just never going to be anything but marginal in providing evidence about sensitivity to a doubling of CO2 in our current climate system, compared to real measurement today, for reasons that others have already given.
There's clear division on this and that for me is very good. Patronising though the person arguing the opposite view is, some of the references provided are helpful and it's good to have as many such issues out in the open.
As for Professor Lindzen I'm a very great admirer of the guy. He tells it like it is - in terms of what constitutes true science. That's my considered view. There's much still to learn from him - and as Judy Curry implied this week, he's gone up a gear in technical sophistication provided for the general public in his presentation to the American Chemical Society. I'm not, I repeat, saying that he's got the estimate of sensitivity right. I think it's too early to say. But he's looking in the right place. I will continue to read his critics, which have included Dr Curry, who has recently said we need to allow for the possibility of sensitivity being between 1 and 6 deg C. That's one heck of a lot of uncertainty and it's surely time, after 23 years trundling of the AGW bandwagon, to try and reduce it. Paleo and GCMs are not going to help.
Richard
I know I'm patronising, so I have nothing to lose. If sensitivity is between 1C and 6C, what is the median? Is it a familiar-sounding number?
And does it explain, to the best of our knowledge, much of what we think we know about how the climate system works?
If not, there are questions to answer.
Looking back, we never really did resolve these:
A low climate sensitivity means that eneregy is shed efficiently and does not accumulate significantly in the climate system if forcings increase. Agreed?
So, assuming a low climate sensitivity, how does a moderate change in solar forcing from orbital eccentricity (Milankovitch) terminate a glacial?
- the only known coherent explanation for the glacial/interglacial cycle is orbital dynamics
- a cold world with a low climate sensitivity cannot be warmed significantly by a minor change in RF (Milankovitch)
- low climate sensitivity is incompatible with a glacial/interglacial cycle governed by orbital dynamics
- climate variation during interglacials is the result of minor changes in RF (there is no evidence for significant changes in RF)
- episodes like the MWP and LIA are inconsistent with a low climate sensitivity
Let us keep it simple. Then there is less scope for confusion in a flowing discussion.
Under the sensitivity framework, can temperature be a forcing?
So you concede, with ill grace and by a side exit. Poor show.
Shub
Oh no. Not this time. You can stop the evasions and twistings and engage properly. Answer the question posed above, don't just pretend it never happened.
Or admit that you cannot sustain your argument.
What about my literal explanation (Sept 1 9:12pm) do you disagree with, and why? Be specific. Do not waffle. Bullet points would be ideal.
Shub
Stop muddling. RF is the forcing. Principally from DSW and DLR. The balance between them can change. The net forcing can change. The effect on global T can change.
Now, when I tried to answer your question above your response was this:
Frankly, that beggars belief. You then simply started trying to confuse the issue and had the gall to try and pose another question.
Stop it. Now.
And explain, in detail, where there problems are in my explanation at Sept 1pm 9:12.
A few lumps of gristle to throw into the pot and stir. It strikes me that definition of terms is rather tricky here. the term sensitivity is certainly used in a number of different ways, and that doesn't help things. (I don't mean specifically in the exchanges above, but in the topic in general). The discussion of current apparent sensitivity versus that in past ages is a really interesting one. What is the effect of time in averaging for instance. Are apparent forcings that we see acting over the short time we have been taking data actually representative of longer time scales? Are there short term fluctuations that are really just noise in the system? In long time scales there is no reason why a low sensitivity could not build up a large temp change over time; you're just integrating a low input over long time The issue of changing forcings is also one I've not see dealt with. In a straight two or three component problem you would certainly expect a simple relationship, but once you have multiple parameters each having interactions with each other, the sytem becomes much more complex, and it's difficult to separate out cause and effect, as well as the potential for different states of the systen to alter the magnitute or even nature of the interactions. So, data accumulates, but real understanding flows slowly behind.
MWP and RWM it seems to me are just small magnitude noise in the overall cycles. I don't want to get too Ptolemaic about it, but whose to say the Milankovich cycles are not similar short term effects in a much bigger system. one of the issues with long term data is it naturally smooths out high frequencies, so deciding what it 'normal' is not easy.
As a chemist with some experience of complex solution equilibria and interactions I'm quite happy with the concept of different temperatures and concentrations producing different outcomes. I think of the climate system as being much more like a complex buffered system than a straight calorimetric problem, which is how it's often treated in the straight energy balance sense.
There are some nice points made in these comments that are all grist to the mill, but I think BBD is a little too simplistic and deterministic in looking at this rather interesting problem.
A few people in the comments have come close to suggesting that there are indeed different sensitivities operating under different timescales and states. I don't see why that's not possible, and consistent with current observed facts.
Just a few penn'orth of general observations.
Cumbrian Lad
Good comment.
See Hansen & Sato above for a discussion of fast feedback CS and long term equilibrium. I think you will ultimately find that I am not so much being simplistic as attempting to simplify. It is difficult to prune away the complexity without damaging core concepts. If I have done so, my apologies.
It would be much better if you do some reading, then return to air you views.
Yes - a sensitive climate reacts to ca 2ky of increased DSW at the peak of the 100kya Milankovitch cycle by warming enough to initiate a massive break-up of the NH ice sheet. The physical dynamics of which, once under way, are self-propelling. The rapid fall in ice-albedo removes this hugely dominant feedback and T rises very rapidly indeed. Then levels off. An interglacial begins, complete with elevated GHGs relative to the glacial period (CO2 rises from 180ppmv to 280ppmv).
GHGs are a 'buffer' against abrupt cooling after peak Milankovitch forcing has waned. That's why interglacials start abruptly and end slowly.
But ultimately it's all about energy balance. Energy in vs energy out. Effects play out over different timescales and are often mediated by initial conditions (glacial vs interglacial). The laws of physics however remain constant. Change the RF and the corresponding change in T will ultimately be the same. Hence the concept of climate sensitivity.
BBD, I didn't anywhere say I had exited. I've just enjoyed reading Cumbrian Lad. I may not have much time to say anything substantial on this until next week. What is vital is the acknowledgement that the system we are dealing with exhibits spatiotemporal chaos. That's why PaulM thinks the concept of sensitivity is a huge oversimplification. Paul certainly agrees with me that you can't pull values out of the hat from little-understood episodes in the past. All the focus should be on what we can discover now. But I may have said that already :)
If I have a fault BBD ( a long shot I know) Mrs.Lad would strongly suggest it is that I read too much. I am familiar with the paper you mention. Quod scripsi, scripsi.
Richard
All the focus should be on what we can deduce by any rigorous means at our disposal. No properly conducted area of study should be closed off (ruled 'inadmissible as evidence') as you insist. That would be profoundly unscientific. Before you can dismiss a paper such as H & S you must critique the methodology and show where it fails. Until this is done, it all stays on the table.
You persist in refusing to accept that a moderately high climate sensitivity (ca + 3C for fast feedbacks) is necessary for glacial/interglacial transitions to be forced by Milankovitch without providing an alternative explanation.
In addition to Lindzen, you mention Spencer as a proponent of low CS. You will find this analysis of Spencer's methodology very interesting.
I wonder if you are also aware that the editor of Remote Sensing has now resigned over the publication of Spencer & Braswell (2011) in that journal.
On a side note, you have also accused me of game-playing, evasiveness, dishonesty, poor judgement and being patronising. While I will happily concede the last, I resent the rest. Can you avoid the catalogue of personal slights in future exchanges? It devalues your commentary.
Enjoy the weekend.
Cumbrian Lad
Forgive me. From your comment at Sep 2, 2011 at 4:31 PM, you do not appear familiar with H & S (2011), either conceptually or methodologically. Perhaps I misread you. I will have another look.
Richard
Apologies - only just now seen the BH article on Wagner's resignation and your comment below.