Rearranging The Deckchairs

Frank O'Dwyer's blog

Bishop Hill - ‘Not Entirely Open About Negative Feedbacks’

Bishop Hill has responded to my earlier post about his accusations against IPCC scientists in a comment here.

[Frank] suggests that the IPCC is being open about negative feedbacks from boundary layer clouds.

I think the answer is,”not entirely”. The Klein and Hartmann paper is discussed in Bony et al and I cover it in Hockey Stick Illusion too:

Later in the same paper, Bony had noted the findings of two earlier researchers, Klein and Hartmann, who had observed a correlation between cloud cover and temperature stability in the tropics. This, Bony reported, ‘leads to a substantial increase in low cloud cover in a warmer climate … and produces a strong negative feedback’. So once again, there was an unequivocal case being made that the feedback from boundary layer clouds is both strong and negative – tending to cool the Earth rather than warm it.

It is a mystery to me that Bishop Hill does not go on accuse himself of engaging in ‘charlatanry’, or at least ‘not being entirely open about negative feedbacks from boundary layer clouds’ here.

Because the above is yet another inaccurate summary from him of what Bony et al 2006 says. In this case, a wildly inaccurate representation of what Bony et al has to say about the Klein & Hartmann Paper, which is this (my emphasis):

Klein and Hartmann (1993) showed an empirical correlation between mean boundary layer cloud cover and lower-tropospheric stability […]. When imposed in simple two-box models of the tropical climate […] or into some GCMs’ parameterizations of boundary layer cloud amount […], leads to a substantial increase in low cloud cover in a warmer climate […] and produces a strong negative feedback.

Note the conditions - the strong negative feedback is seen only when the results of Klein & Hartmann are imposed in certain models.

Furthermore Bony et al immediately goes on to say:

However variants of lower-tropospheric stability that may predict boundary layer cloud cover just as well as the Klein and Hartmann (1993) parameterization, would not necessarily predict an increase in boundary layer cloud in a warmer climate.

So in addition to this strong negative feedback being seen only in certain models, it may not exist at all.

It is hard to see how Bishop Hill gets from an effect that may or may not exist, and then only according to some models, to this:

there was an unequivocal case being made that the feedback from boundary layer clouds is both strong and negative

Bishop Hill on Charlatanry

Update: Sandrine Bony confirms that there is nothing inconsistent between her 2006 review and the IPCC AR4 WG1 discussion on cloud feedbacks. See here

Bishop Hill accuses some IPCC scientists of ‘Charlatanry’ here.

The effect of low level clouds was touched on the Hockey Stick Illusion, where I briefly discussed a review paper by Bony et al (2006) looking at the low-level clouds (boundary layer clouds, in the jargon). I was struck by how different Bony’s story on the effects of low level clouds is to Tom Chivers’. Here is what she said in her paper:

Boundary layer clouds have a strongly negative [feedback effect] … and cover a very large fraction of the area of the Tropics … Understanding how they may change in a perturbed climate therefore constitutes a vital part of the cloud feedback problem.

So my understanding of the scientific literature is that low level clouds actually cool the planet. In Tom Chivers’ defence, it’s easy to get confused in this area because as readers of the Hockey Stick Illusion know, when the IPCC came to discuss boundary layer clouds in the Fourth Assessment Report, they lifted Bony’s text almost word for word, but making one rather important alteration:

Boundary-layer clouds have a strong impact … and cover a large fraction of the global ocean … . Understanding how they may change in a perturbed climate is thus a vital part of the cloud feedback problem.

Not all climate scientists are charlatans, and those who suggest they are are wrong. That said, I hope Tom will concede that there is a real problem with charlatanry among some scientists working on the IPCC assessments.

However Bishop Hill has made one rather important alteration of his own here. What Bony et al (2006) actually says is this:

Boundary layer clouds have a strongly negative CRF (Harrison et al. 1990; Hartmann et al. 1992) and cover a very large fraction of the area of the Tropics (e.g., Norris 1998b).

Bishop Hill paraphrases this as [negative feedback]. However CRF stands for Cloud Radiative Forcing, which is a forcing, not a feedback. Low level clouds would only represent a negative feedback if they tend to increase in a warming world, which Bony et al (2006) makes clear is debatable. This is rather the point of the phrase Understanding how they may change in a perturbed climate is thus a vital part of the cloud feedback problem.

What then of the IPCC’s wording, is it really misleading as to whether low level clouds could represent a negative feedback? No. It explicitly states that they could be.

Let’s look at more of the relevant paragraph from IPCC AR4 WG1, which Bishop Hill only partially quotes (my emphasis):

Boundary-layer clouds have a strong impact on the net radiation budget (e.g., Harrison et al., 1990; Hartmann et al., 1992) and cover a large fraction of the global ocean (e.g., Norris, 1998a,b). Understanding how they may change in a perturbed climate is thus a vital part of the cloud feedback problem. The observed relationship between low-level cloud amount and a particular measure of lower tropospheric stability (Klein and Hartmann, 1993), which has been used in some simple climate models and in some GCMs’ parametrizations of boundary-layer cloud amount (e.g., CCSM3, FGOALS), led to the suggestion that a global climate warming might be associated with an increased low-level cloud cover, which would produce a negative cloud feedback (e.g., Miller, 1997; Zhang, 2004).

That seems pretty clear. So, just who is the charlatan?

It’s also interesting to note that the case which Bony et al (2006) makes for low level clouds potentially representing a negative feedback is almost entirely based on models, which Bishop Hill normally poo poos, though oddly enough not on this occasion. Meanwhile empirical observations have since suggested that the net feedback of clouds is a warming feedback.

I wonder whether readers of The Hockey Stick Illusion will know that.

Blog Comments and Censorship

Matt Gemmell has collected some interesting thoughts on the idea of switching off comments on blogs. However one thing I have not seen mentioned in this whole discussion so far is the relationship between blog comments and censorship—and in my opinion the potential for censorship is greatly reduced with comments off.

This is most obvious when you look at political blogs, where discussions can become very heated. On such a blog with comments, it’s very easy to make the assumption that the comments on the site itself are the whole discussion. Very often, they aren’t.

Especially on blogs with a strong partisan viewpoint, individual participants may be banned entirely, or their comments may be edited by the blog host, without any indication that this has happened. This occurs not necessarily because those contributors are trolls or rude (though that of course is also common) but often enough because their viewpoint and/or the evidence they bring in support of it is inconvenient. For example in the global warming ‘debate’, both sides (rightly or wrongly) claim censorship of comments exists on popular blogs such as Realclimate and Watt’s Up With That.

In a centralised discussion with blog comments administered by a site host with a strong viewpoint, some degree of such censorship is almost inevitable. Whereas in a decentralised discussion across individuals’ own blogs, this kind of censorship is simply not possible.

Of course, some blogs will command almost all the audience, while others will command almost none, so the ‘right of reply’ is correspondingly skewed, but that is unavoidable. Still I think it’s clear that ‘comments off’ helps in so far as it decentralises the discussion and creates the expectation among readers that if they wish to get the whole story, they need to go look for it.

Naturally, none of this is going to help with the problem of finding rebuttals to political arguments, for those who are happy to stay in an echo chamber of those who agree with them. These people will never even look. But at the very least it makes it less easy for them to pretend that they are participating in some kind of ‘debate’ on a level playing field when they aren’t.

Cuckoo Clock

Bishop Hill writes about the NOAA surface temperature reconstruction:

We have seen this kind of thing before: the adjustments to the series produce cooling at the start of the series and warming at the end.

And we’ve seen this kind of cowardly and baseless insinuation that scientists are engaged in fraud before too.

(Of course, this doesn’t mean that it hasn’t warmed; only that the trend may be being exaggerated.)

And of course, the trend may not “be being exaggerated” at all.

The possibility that the adjustments are warranted, that the upward trend is therefore actually closer to the truth, and is entirely because of global warming seemingly never even occurs to him.

I think this kind of thing must set alarm bells ringing among reputable scientists.

I think this kind of thing must set alarm bells ringing only among barking lunatics. When multiple independent temperature reconstructions have come up with essentially the same answer as NOAA, objecting to one of them is like looking at six clocks all telling roughly the same time, and claiming that one of them is fast.

To top it all this (libellous?) insinuation that NOAA scientists are engaged in fraud comes only a day after approvingly posting this handwringing about one of their own:

Roger has been publicly libelled and abused across the world to the detriment of his reputation and has suffered distress, inconvenience and damage to property

Sound familiar? Truly you can’t make this stuff up.

(Amusingly, Bishop Hill has also campaigned for reform of the libel laws, which these days seems as understandable as it is hypocritical.)

Usability vs Individuality in the Mac App Store

John Gruber over at Daring Fireball has posted an interesting article about Uniformity vs Individuality in Mac UI design, prompted by a critique of the custom UI of the new Twitter for Mac app.

Key quote:

it’s worth keeping in mind which of his criticisms fall under “this is non-standard” and which fall under “this isn’t good design”.

But this misses a crucial point which is that, almost always, “this is non-standard” implies “this isn’t good design”. Users have a huge amount of accumulated knowledge about standard UI elements which work with every app. So if you want them to learn your ‘custom’ way of doing something, especially something basic, you better have a damn good reason. And you probably don’t.

In the case of the new Twitter it has (as usual) lots of nice and innovative UI touches and is visually stunning. However it is hard to see its lack of a window title bar as anything other than an epic and unnecessary usability fail.

If you’re anything like me you probably went through something like the following thought process on encountering this:

  1. No title bar?
  2. So how the hell do I move the window then?
  3. The little thing with the traffic lights must be the title bar
  4. Jesus it’s tiny
  5. I’ll try to drag it without clicking the little buttons
  6. This can’t be right
  7. Maybe the sidebar then
  8. I’ll try to find somewhere in the sidebar where there is no control and drag that
  9. OK that worked!
  10. Jesus, why do it this way?

Later, I found out that you could in fact drag anywhere in the sidebar, even on a control, and it worked. (Of course, if users expect that to work in every other app, they’re in for some big surprises.)

But this still leaves the question of ‘why’ unanswered. Until the other day, how to drag a window is not something I have had to think about about for over 20 years. Whether you’re using Windows, Mac, Ubuntu, X11, though the look may be different it works pretty much the same way on all of them1^. And that’s true going back umpteen versions too. How to drag a window has to be one of the most portable UI skills there is.

So is there really a good reason to invent a new way to do it for one app, never mind every app?


Fundamentally I think seeing this as ‘individuality’, instead of just bad design, stems from mixing up design (as in ‘looks well’) with design (as in ‘works well’). One is a visual design problem and the other is an engineering problem.


“Difficulty?” exclaimed Ford. “Difficulty? What do you mean, difficulty? It’s the single simplest machine in the entire Universe!”. The marketing girl soured him with a look. “Alright, Mr. Wiseguy,” she said, “if you’re so clever, you tell us what colour it should be.”

The only exceptions to ‘drag the titlebar to move the window’ I can think of offhand are a handful of apps along the lines of Quicktime player, which have no window chrome at all. But with these it’s still reasonably intuitive that you can drag anywhere in the window to move it, because there is nothing else that you can drag. Also as there are no controls, it feels like you can experimentally drag anywhere without unintentionally making the app do something.

Does Open Geodata Matter?

I said this quite a while ago. But looks like finally others are getting the idea too:

Here is the problem: These efforts at creating an underlying database of places are duplicative, and any competitive advantage any single company gets from being more comprehensive than the rest will be short-lived at best. It is time for an open database of places which all companies and developers can both contribute to and borrow from.

Indeed. But why should the driver be whether it is to these companies competitive advantage or not? How about thinking about what is to the advantage of the rest of us - i.e. the people contributing the information in the first place?

But in order for such a database to be useful, the biggest and fastest-growing Geo companies need to contribute to it.

Well, not really. All it takes is for people to stop shoving their place information into proprietary silos, and put into genuinely open licensed efforts instead.

You’re Entitled to Arguments, but Not (That Particular) Proof

Less Wrong has an excellent post on Creationism and Global Warming ‘Scepticism’:

We are, I think, dealing with that old problem of motivated cognition. As Gilovich says: “Conclusions a person does not want to believe are held to a higher standard than conclusions a person wants to believe. In the former case, the person asks if the evidence compels one to accept the conclusion, whereas in the latter case, the person asks instead if the evidence allows one to accept the conclusion.” People map the domain of belief onto the social domain of authority, with a qualitative difference between absolute and nonabsolute demands: If a teacher tells you certain things, and you have to believe them, and you have to recite them back on the test. But when a student makes a suggestion in class, you don’t have to go along with it - you’re free to agree or disagree (it seems) and no one will punish you.

Read the whole thing