Exxon Geosciences Union?

There's an interesting rumour floating around in EGU circles: apparently some people are considering the possibility of sponsorship from an oil company, specifically Exxon. The EGU is a broad church and some people (eg the solid earth types) see no problem with this, but of course many climate scientists find it problematic, to put it mildly.

It's not clear to me what is really in it for the EGU. Maybe they would like to have more money to spend on "good causes" but (AIUI) they are not actually in any financial difficulties. Surely they could raise money for specific goals without branding either the whole organisation or the EGU General Assembly, which is a fabulous interdisciplinary meeting. I can just imagine "The Exxon Climate Lecture", in which they fly over someone like Lindzen (or worse, jokers like Monckton or The Execrable Crichton [did I really coin that epithet?]) to feed soundbites to waiting Faux News reporters. Thanks, but no thanks.

If the idea goes ahead, I predict a bloodbath - but for that reason, I don't think there is any serious prospect that it will happen. As a mildly interested outsider, the EGU seems to work very well as it is. Why fix what isn't broken?

Food and fatness

Well I was going to blog about this article in which a Japanese TV chef utters the idiotic Nihonjinron nonsense that Japanese people have "DNA more suitable for rice than bread."

But then I read this article which claims that British people can't help eating too much and not doing enough exercise. And I can't honestly poke fun at some Japanese TV Celeb spouting rubbish when whole committees of scientists are saying things like that.

Here we have Sir David King saying "What we have to do is pay an enormous amount of attention to how much we exercise we take and how much food we eat." As just about anyone who cycles a modest distance to work can tell you, that is simply nonsense. If I didn't like beer I'd waste away. Maybe it's not fashionable to take a modest amount of exercise most days, but neither is it remotely difficult for the vast majority of the population (and while I'm in Japan now, I cycled in the UK in 3 different towns and 4 jobs).

In unrelated news, Mr Peter Bonehead (MP Wellingborough) is trying to criminalise any child who rides a bike without a polystyrene egg-tray on their head. As usual, his "argument" is the same old discredited lies and nonsense regularly trotted out by those whinging interfering do-gooders Be-Hit, and the Dept of Get-those-pesky-cyclists-off-the-roads^WTransport has fallen for it hook line and sinker (read cyclehelmets.org instead for some rational analysis). Shame the hand-wringers can't start up a campaign about something meaningful where they might do some good...like the rapidly increasing rate of obesity among schoolchildren for example. I dunno, maybe some exercise would do them good...like cycling, perhaps?

Peace, man

So apparently "the IPCC" has won the Nobel Peace Prize. Al Gore got the Fiction Prize.

According to the BBC, the IPCC is "Made up of more than 2,000 of the world's leading climate experts". I don't know who that counts and who it doesn't. But just in case it counts contributing authors, my share of the $1.5m can be sent to me c/o FRCGC, Yokohama, Japan :-)

Who was it that said that climate scientists were just in it for the money...

Seriously, I think the people who actually did the work did a good job overall, despite having some quibbles over the details (that's only WG1 of course). But for all that it's a worthy effort, it's depressing to think that no-one else made a greater contribution to world peace over the last year.

Gore gored

I'm surprised this hasn't already made more of a splash in the blogosphere, as it's been floating around in the press for a day or two already. Anyway, the gist of it is that An Inconvenient Truth can only be shown in British (English?) schools if accompanied by some guidance notes pointing out 9 significant flaws in the coverage of the science.

I saw AIT recently, and while it does not make up lies out of whole cloth in the way that Durkin's Swindle did, I was certainly uncomfortable with parts of the story Gore presented. There was a clear intent to persuade as well as inform, and he stretched reality to fit his agenda in a few places. So I think on balance the judge's decision is pretty fair.

Sorry to be boring and uncontroversial - but maybe agreeing with the judge will turn out to be controversial among climate scientists, so I await the views of others with interest. It's worth noting that most/all intelligent reviews have noted some problems with the original film (eg Eric Steig on RC: "There are a few scientific errors that are important in the film", and Stoat sez: "Its more or less OK, um, except the bits that aren't, and except its completely without qualifications, and consistently on the high side") so I don't expect too much harrumphing about senile judges. OTOH, bloggers have to harrumph about something, or they might as well not blog at all.

Debito packs it in

I was saddened to see that Arudou Debito, scourge of racist onsen-owners everywhere, has basically given up on his employer (a university in Hokkaido) and is looking for a new job.

The basic reason for leaving? Being denied a sabbatical, strung along with a line of bullshit as to the reasons why, and eventually getting to the bottom line: he's not worth anything to the old farts running the place. He's just an English teacher, after all.

I know Debito rubs some people up the wrong way but I have plenty of admiration for the effort he has put in to standing up for his, and others', rights. Moreover, he is the archetypal well-integrated immigrant, fluent in Japanese, with a Japanese (now ex-)wife, children, house, and indeed Japanese citizenship (born a US citizen, David Aldwinckle). If he is still hitting this sort of brick wall at his stage (and it's not as if a year of sabbatical is an unreasonable expectation for an academic after 14 years of service), then really I don't need to waste any more time wondering whether I have a long-term future here. I hope he finds something suitable for his talents (and I second the sentiment in his comments that something more explicitly activist-oriented may be more suitable than more teaching with activism as a side-line).

Incidentally, I was at a book launch party for the IPCC AR4 last week, organised by the Tokyo office of CUP. We were treated to the spectacle of a succession of Japanese researchers basically telling us all about what a wonderful contribution Japan had made to this project. Needless to say, there was no mention of yours truly, cited (along with jules) in 3 chapters and Contributing Author for one, all while employed full-time in a Japanese research institute. I realise that's hardly a big deal and I wouldn't have noticed were it not for the inordinate fuss they made over someone who managed to get his name mentioned on a figure or something. But it did bring it home to me just how much easier it was for us, as complete outsiders to the process, to affect (albeit in a minor way) the outcome of the massive international bureaucratic behemoth that is the IPCC, than it is to have any influence in the institute where we are nominally "Senior Researchers".

Jules was also invited to attend this event (by a senior manager at FRCGC who helped organise it) "as a researcher of Hadley". Yes, after 6 years here, we are still just visiting researchers to some. She didn't have the heart to tell him that she'd only ever been to the Hadley Centre about twice.

Probability, uncertainty, models and climate

I recently attended the second installment of this sequences of workshops, this time in Durham. It was if anything better than the first, not merely due to the fact that I had a trouble-free journey there, but also because it seemed like the Bayesians and climate scientists were better able to communicate this time around. As I've mentioned, Marty Weitzman's Dismal Theorem made a brief appearance but the most interesting discussion focussed on if and how we could use model output to generate (or inform on) the detailed probabilistic predictions of regional climate change that are increasingly being made.

Lenny Smith gave a very entertaining rant on this topic, which I found very useful as I'd been aware of his scepticism for some time, but not quite understood the reasons for it. Just for clarity, he is not sceptical of the broad picture of global climate change in terms of the expected large-scale future warming, but rather of the ability of models to provide such detailed predictions as say "typical" weather time series for specific locations and seasons several decades ahead (which UKCIP is promising). As he further points out, the time scale on which credibility may be lost is not the decades it takes for such predictions to be falsified observationally, but rather the much shorter time scale over which someone produces a new, conflicting, prediction with the next "bigger and better" model. I've generally been thinking in terms of global and large regional scales, with variables such as (ok, exclusively) mean temperature so had not really considered the detailed predictability of local climate changes, but he certainly painted a very persuasive picture of the difficulty of this. Note this is not the trivial "weather versus climate" meme, but rather the question of whether a model can usefully inform on (eg) the longest sequence of consecutive hot days in a summer, when it simply does not adequately simulate the processes that control long sequences of hot days. It is the statistics of "weather" events such as these that actually matters to end-users, much more so than global annual mean surface temperature.

However, I do think there is room for coexistence between his view and the Bayesian approach. Indeed it was suggested that his criticism was more an attack on a straw-man of "naive Bayesianism" (albeit that this naive Bayesianism is pretty much the path that has been followed so far in climate science) rather than on the principles of Bayesian probabilistic prediction themselves. The distinction as I see it is that the naive approach which Lenny is criticising is the generation of some model (ensemble) output, dressing it up in some sort of uncertainty kernel (to represent "model inadequacy") and presenting this as a pdf. Whereas perhaps a more sound way of addressing things is to start off with a prior on the future operationally-defined variable of interest, and then consider through the likelihood function to what extent the outputs of (highly imperfect) model runs should cause one to update that prior at all. That doesn't amount to any sort of get-out-of-jail-free card - all the hard judgements still have to be made - but it might perhaps encourage climate scientists to address the issues within in a more comprehensive, coherent and plausible framework than they have done previously.

My talks (one on my own behalf, one of jules' work) were fairly unadventurous. I was relieved to see that the uniform prior really does seem to be increasingly acknowledged as a dead duck now, with one of the climate scientists bothering to mention as an aside that of course one could not pretend that a uniform prior was really "ignorant" (only last year, the IPCC was asserting precisely the opposite, but perhaps this little episode has been airbrushed out of history now). Other than that, there was a range of interesting presentations, some maths that was way over my head, and other stuff I thought was probably wrong, including a claim that seems to contradict some well-established mathematical theory, of which the claim's originator was apparently not aware. Par for the course really :-)

Weitzman's Dismal Theorem

This got briefly mentioned at a workshop I attended last week, and has been splashed around the internet a bit so I might as well add my ¥2. Marty Weitzman has circulating early versions of his manuscript widely over a number of months (latest one can be found here), but despite several attempts I've not yet managed to convince him of my POV.

His paper, and main result ("we're all dooomed") has two basic components. The first is that under some assumptions about how one learns probabilistically about future hazards such as climate change, the pdf (eg of climate sensitivity S) will inevitably have a "long tail". By "long tail", he does not mean it will necessarily assign a particularly high probability to extreme cases such as P(S>6C), but rather that the pdf will naturally follow a shape that "only" decreases as a polynomial function in S (say 1/S² or 1/S³), rather than say the exponential decay of a Gaussian (e^-cS2) or other friendlier functions. The second component of his argument is the observation that under any reasonably risk-averse attitude, then as one considers increasingly high impacts, the loss in utility arising from such impacts increases more rapidly than their probabiity decreases (based on the long-tailed pdf), giving a divergent sum, infinite expected utility loss and a conclusion that Something Must Be Done. Or perhaps, that we are all doomed whatever we do.

But there are IMO a few problems with this work. I've had a long, interesting but ultimately fruitless exchange of emails with Marty, in which I failed to persuade him of my points. He's a famous economist and I'm not, so maybe I am wrong. But it's my blog, so here are my opinions, for better or worse.

Firstly, I disagree wth how he has characterised the nature of the uncertainty in the system. He models it as if S (climate sensitivity) is a sample from an unknown distribution, and the only way in which we can learn about S is to draw samples from this distribution in order to infer its shape. AIUI this is fundamentally incompatible with all of the Bayesian work that has been done, in which S is viewed as a constant about which we learn in various ways, with the pdf being simply an expression of our current uncertainty over S, rather than anything intrinsic to S itself. This may seem like a semantic detail at first but in fact it appears to be fundamental to his analysis. To appreciate the distinction, note that under his viewpoint, our estimate of S will converge to a pdf of finite width which must cover all of the recent individual estimates, whereas I (and I believe all climate scientists, even those with who I have had strong disagreements recently) would say that our pdf of S will in principle converge towards a point estimate, especially if we were to carefully operationalise the definition and then go and do a suitable experiment on the whole earth system, which is a plausible experiment at least in thought (we may in practice lose interest in estimating S).

I do wonder if it might be possible to rescue the mathematical content of what he has done via some reinterpretation of his framework but he doesn't seem to accept (or perhaps understand) my complaint in the first place, so I can't see that happening (at least not in his manuscript). I actually don't have any fundamental objection to distributions with polynomial tails, in fact this paper presents such a distribution and I had already realised when writing it that in principle it leads to an unbounded loss under even for a rather tame quadratic cost function (although I truncated the pdf at 20C for pragmatic reasons). My criticism of much previously published work on estimating climate sensitivity is not that their estimates have long tails, but that the probabilities in these long tails are unreasonably high due to the pathological decisions which have been taken along the way.

Next, we have the utility function. I'm not convinced that it makes sense to extrapolate some convenient (perhaps also theoretically and/or empirically justifiable) functional form right down to the singularity at 0 (yes, complete destruction of the entire world economy). But not being an economist, I don't have any particular grounds to criticise and it would be rash to express too much scepticism based on nothing more than my own ignorance of these matters.

Notably, although he talks in terms of climate sensitivity, there is nothing in Marty's maths that depends specifically on a doubling of CO2. A rise to 1.4x (which we have already passed) will cause half the climate change, but that would still give an unbounded expected loss in utility (half of infinity...). By the same argument, a rise even of 1ppm is untenable. Come to think of it, putting on the wrong sort of hat would become a matter of global importance (albedo effect).

When the Dismal Theorem was mentioned at the workshop, a wag in the audience (who had I'm sure already seen the full manuscript) described it as not so much an economic disaster, as an economics disaster. If it becomes widely endorsed by the economics community (Richard Tol is already on record as enthusiastically endorsing it, and there's a long list of acknowledgements to people who presumably did not all say it was bunk) it may come to have more significance in terms of determining to what extent modern economic theory can (or cannot) be used to credibly inform decision making under uncertainty, than in actually informing those decisions. Time will tell.

The future face of conferences?

Having just flown around the world for another meeting, I can't help but wish that someone would put this into production. It's good to meet people occasionally, but given the option, I'd generally prefer to save the cost, carbon emissions, and travel time (or more likely, I'd "attend" more meetings if I could do so virtually).

Mind you, even a decent web-cast of the presentations would be a start, and this would substantially cut down on the technical problems of multi-way communications. Why isn't anyone doing this already (at least, not that I know of in climate science)?

Climate sensitivity is 6C?

Belette alerted me to this article discussing what appears to be a new manuscript by Jim Hansen (which I have not seen, I'm basing this post purely on the quoted excerpt). In the manuscript, Hansen claimes that the "long term" climate sensitivity is 6C. Hansen has long been of the mainstream "climate sensitivity is about 3C" school of thought so it's interesting to see what appears at first glimpse to be a startling u-turn.

But things are not quite what they seem. Generally, when people talk about sensitivity, they mean the sensitivity of the atmosphere/ocean/sea-ice system to changes in boundary conditions such as (especially) CO2 and also other forcings such as the minor greenhouse gases and changes in solar forcing. The relatively slow-moving ice sheets, which can significantly affect the planetary albedo, also are generally placed in this "boundary condition" category.

In this new manuscript, Hansen simply considers the ice sheets as part of the interactive system - which of course they are on a long enough time scale. For colder climates, the ice sheet albedo change roughly matches the GHG forcing, so if we regress temperature against GHG forcing alone (rather than the conventional approach of adding the GHG and ice sheet forcing together) we get a result of about 6C per doubling of CO2, double the conventional figure. (There is no need to get into the question of lags vs leads and cause vs effect here, it is just a matter of what a cold climate state looks like compared to a warmer one.)

On a long enough time scale and looking backwards in time, this approach is not unreasonable. However, looking forward to a warmer climate, there is no significant ice sheet left still to melt (significant in terms of global temperature, that is - of course if the remaining ice sheets melt then sea level rise could be important for other reasons). So therefore there is no obvious reason to think this 6C value is the appropriate one to use in the context of ~100 years or more of future warming. Hansen appears to admit as much in his text, so I'm not really sure what the point of his article is. There's a vague claim that future feedbacks from vegetation will just happen to make up for the fact that the ice sheet feedback disappears, but there is no evidence shown for this and it seems nothing more than anthropomorphism to just say: "The real world will be aiming on the longer run at a warming corresponding to the higher climate sensitivity." Although some people expect a positive effect from the carbon cycle, expecting it to double the warming seems a stretch, to put it mildly.

[Jules spotted Harry Elderfield taking a similar approach in analysing paleoclimate data a few years ago in a poster at the EGU, but I can't find a ref to it - perhaps we (and/or others) persuaded him it was an inappropriate angle to pursue.]

Blognapped!

Well no sooner do I go away for a week than Jules makes a "special guest appearance" or three. Suppose I can't really complain since her name is invoked in the URL. But rest assured, the riot troops are in the lounge, tear gas grenades have been thrown (well, the after-effects of a Loch Fyne kipper and 24h of travelling come to much the same sort of thing) and I expect to have fully suppressed this insurgency shortly.

Actually, given that someone felt sufficiently motivated to comment, I may encourage her to write more.