Saturday, December 31, 2005
Thursday, December 29, 2005
You can find the debate about 37 minutes into the
Let me explain further. Many of Japan's biggest companies operate a "dual track system" with one career track for managers, and one for clerical staff. The managers have a proper career structure and (at least eventually) get paid far more, and the clerical staff have basically no promotion prospects at all. Maybe that doesn't sound too unreasonable, but the shocking fact is that essentially all men are put in the management track, and almost no women. For example, in 1991 JAL (the flagship air carrier) hired 147 men and 3 women to the career track, in addition to 52 women to the non-career track. For the financial company Tokyo Marine Insurance, the equivalent figures were 424 men and 24 women hired to career-track positions and 553 women and no men to the non-career track (figures from here). Clearly this is institutionalised discrimination on a scale that would not be considered remotely acceptable in the UK. It can certainly be argued that societal attitudes play a role - some women don't want to commit themselves to long hours and the risk of relocation, although it's also possible that these conditions are added as a way of discouraging them rather than because they are really necessary.
It remains to be seen if their proposal to outlaw "indirect discrimination" will have sufficient teeth to address this. Otherwise, this will not be a "Gender Equality Plan" as a westerner would understand it, but rather a "Please have babies, but don't give up your menial dead-end job" plan. The fact that they feel the need to specifically mention "Doll Day" (a festival in whch young girls are basically taught that they should grow up to be a good wife and mother) suggests to me that they don't plan significant changes.
I promise I'll get back to posting about science soon, honest...
The nearest main station is Tokyo itself, and immediately on leaving the station - or rather, joining the queue to leave the station - it was obvious that we were not going to go the wrong way and miss the event:
About an hour later, we eventually shuffled the 2 blocks to reach the lights.
This picture really doesn't do them justice - they were much more boring and inconsequential than they appear. Folks, save yourselves the bother, look at the posters on the trains, and stay away. Or if you must go and don't mind missing out on walking under the arch at the very start, approach via a side-street half way along and avoid the queues.
Wednesday, December 28, 2005
As a further update to my previous post, it looks like the decline in total population (even including immigration) has happened sooner and more markedly than expected, with preliminary census figures showing a year-on-year population drop of 20,000 to October 2005. This figure includes foreigners with more than 3 months of residence, so I'm not quite sure how it squares with the recent previous estimate that a small excess of deaths over births this year would be cancelled out by immigration. But anyway, it's the first fall since records began in 1920 (excepting a one-off in 1945), and it seems certain that next year will see a substantial fall.
This article suggests that the drop in numbers might be easier made up with robots than people...
Wednesday, December 21, 2005
A year or so ago, the trees were heavily pruned, right back to ugly bare stumps. According to this newspaper comment, it was to discourage the birds which were considered to be making a mess. At the time I was disappointed that this attractive area would be so gratuitously uglified just in the name of "tidiness".
Walking past the pond at the weekend, we saw that the area has been taken over by flocks of seagulls and pigeons. As a consequence it's covered in bird shit, far worse than it ever was before. I can't quite say "told you so" but it can hardly be surprising that these natural scavengers have moved in to claim an open space. I only hope that the authorities learn from their mistake and allow the vegetation to re-establish itself rapidly, rather than taking the next logical step of filling up the pond with concrete.
Monday, December 19, 2005
RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists. We aim to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary. The discussion here is restricted to scientific topics and will not get involved in any political or economic implications of the science.And I should make it clear at the outset that I think they are doing a really good job overall. But I have to wonder about some of the issues they've chosen to highlight recently. They have always had an inordinate focus on the hockey stick affair (from which none of the main protagonists emerge with a great deal of credit IMO), which in scientific terms is really not that important. At least this can perhaps be excused by the fact that it has been a high-profile story in the public eye, even if it doesn't really deserve to be. More recently, they have plucked a couple of fairly minor papers out of relative obscurity and thrust them into the limelight for no apparent purpose other than to tear into them (here and here). The authors' crimes? In each case, they included a throwaway phrase which appears to pose some sort of challenge to the "consensus" view. In both cases, the papers make some valid points, and I don't find the RC rebuttals entirely convincing. But it's not so much the science I'm objecting to, as the tactic itself, which I don't think is really warranted. With RC's dominant influence on the web comes a responsibility to treat people - and the issues - fairly. They risk looking more like a playground bully than an honest broker, especially with the rather obvious targetting of anything containing sceptic-friendly phrasing. It's a rare scientific paper that does not contain a single dubious sentence, and any significant error can always be dealt with by a "Comments on ..." reply within the peer-review system.
In contrast (and not just to prove I can hand out compliments as well as criticism) the Ruddiman article seems like a shining example of how it should be done - I would hazard a guess that most RC contributors think his ideas are rather speculative, but they still made room for sensible debate. Please, let's have more discussion of the interesting and/or important science, and less acting as judge, jury and executioner towards anyone who is perceived to be stepping out of line.
[Oh, ok, a few words about the science in the RC articles. The first article refers to comments by Esper et al suggesting that a more variable past would imply lower sensitivity to anthropogenic perturbations. While Esper et al's point is somewhat awkwardly made, it's not necessarily quite as stupid as the RC article implies. If the past was more variable, this could suggest that the variability of natural forcings is stronger (either in absolute terms, or in terms of the climate's response) than is currently thought. This might lead to some re-evaluation of the radiative forcing concept (which is only an approximation, not a law) and a conclusion that anthropogenic effects aren't quite as big as we think. However I think in practice we can accommodate significant historical variability without being too worried about implications for our understanding of climate sensitivity - if anything, the smoothness of the MBH98 reconstruction is harder to swallow.
As for the Cohn and Lin paper on trends, discussed here - it is hard to deny that scientists in all fields have sometimes used somewhat simplistic statistical tests and assumptions, and this provides a rich seam of opportunities for people to "rediscover" the limitations of these approaches. I recall this presentation at the EGU a couple of years ago making effectively the same point (it seems to have appeared recently as a paper here, which I've not read), and I've even discussed the issue myself on occasion. It hardly seems as cut and dried as RC's presentation would seem to imply.]
Sunday, December 18, 2005
It seems likely that this "population decline" headline is slightly misleading. Even if deaths outnumber births, net immigration is likely to keep the total resident numbers rising slightly this year. Here is an article discussing the issues:
Conservatives eager to preserve what's left of Japan's "man at work, woman in the home" family model have been loathe to vastly expand the day-care system, for instance, for fear of encouraging more women to join the work force.
Another obvious possibility - loosening Japan's tight immigration laws to allow more foreigners to come here to work - has been blocked by a widespread distrust of outsiders and fear that foreigners would disrupt the country's social order.
I know I joked previously about the car-mounted wind generators on show in Japan, but in that case at least they were clearly designed as a promotional exercise rather than a serious attempt at power generation. These guys, on the other hand, are for real! Listen to the voice-over on the movie if you don't believe me - this is not being presented as a convenient way of powering off-grid road signs in remote areas, or a way of making speed bumps slightly useful. They actually claim "free electrical energy" and suggest installing them widely in cities:
...designed to generate electricity using kinetic energy from passing traffic. This energy, which is free, would otherwise be lost... The ramp...consumes no aditional fuel, produces no emissions, and is environmentally friendly.
I hope it doesn't really need pointing out to my reader why this is bogus - the ramp steals energy from the passing vehicles, meaning that their fuel consumption is necessarily increased and it's a racing certainty that the overall efficiency of power generation from oil to electricity is way below that of a competently designed power station, for example. I am astonished that anyone with the technical competence to actually design and build such a construction should not be aware of the fundamental physical law that it claims to break.
As an aside, I can't imagine that it would be much fun to cycle over one, still less with a car overtaking simultaneously. But I'm optimistic that no-one will actually get taken in by their claims.
According to this BBC news article, my assessment of the competence of local authorities was badly misplaced:
More than 200 local authorities had expressed an interest in ordering the £25,000 ramps to power their traffic lights and road signs, Mr Hughes said. Around 300 jobs are due to be created in Somerset for a production run of 2,000 ramps next year.What a bunch of numpties. I can only hope the manufacturers go bust before too much taxpayers' money gets wasted on these stupid contraptions. Even from the local authorities' narrow viewpoint (ignoring the added cost on the motorist, and the pollution they will generate), the payback time will be decades.
Thursday, December 15, 2005
The accompanying box (link) "Challenges of being a Wikipedian" mentions William Connolley's involvement in the "climate wars". The fact that Wikipedia works at all suggests to me that most errors are due to ignorance rather than malice, but a handful of trouble-makers can clearly make quite a nuisance of themselves. I'm not really convinced that it's worth the effort but I'm glad someone else is :-)
There's some slightly odd spin in the Nature article, on the number of contributors:
As well as comparing the two encyclopaedias, Nature surveyed more than 1,000 Nature authors and found that although more than 70% had heard of Wikipedia and 17% of those consulted it on a weekly basis, less than 10% help to update it.A figure in the region of 10% seems like an extremely high contribution rate to me. I would have probably bet on 1% or lower - and how many contribute to usenet or other interactive internet-based media such as blogs, I wonder? Note that this figure represents about 80% of those Nature authors who actually use it regularly (17% of 70%)! In contrast to his tone, I find such a high participation rate to be very encouraging.
The article mentions that the organisers plan to introduce "stable" versions of pages once they reach a high enough quality. In the meantime, here's a small tip for users: when referring to a Wikipedia page, always use a specified version rather than linking to the current editable page (you can get a permanent link to the current version from the "permanent link" in the "toolbox" on the LHS of the page, or use the "history" tab at the top to look though older versions - eg here is a decent page on the Earth Simulator, but this version - although identical at the time of posting - may be changed at any time). That way, at least you know your readers will get to see what you saw, rather than some potentially very different (possibly vandalised) version. Checking the history also allows you to see how controversial the page is. Of course this doesn't ensure that the information is correct, but anyone who bets the farm based on a single unverified web page pretty much deserves what they get anyway.
Friday, December 09, 2005
Guess who banks with them? Yes, yours truly. But I'm thinking of upgrading to an under-the-mattress account for easy access and extra security :-)
From his rather curt reply, it seems clear that he is not prepared to consider a wager at all.
[I'm going to be pedantic this time and refer to the circulation in question as the North Atlantic Meridional Overturning Circulation (MOC for short). The name "Gulf Stream" is IMO best restricted to the rapid surface current flowing north in the Caribbean/Gulf of Mexico area close to the east coast of the USA. Some of this doesn't get very far north before returning south at or near to the ocean surface (essentially forming a large clockwise gyre in the Atlantic), but the rest continues flowing further north, up to the latitude of the UK and beyond. This bit, sometimes called the North Atlantic Drift, is what keeps NW Europe mild in winter. When the water gets cold enough, it sinks (is mixed with deep water via convection) and returns at depth (there's a diagram here, described in this article by Stefan Rahmstorf). It is this northerly branch that Bryden claims to have decreased markedly, based on estimated changes in how the return flow varies with depth (more of it is coming back near the surface, implying a stronger subtropical gyre and weaker MOC). One possible mechanism for this would be if the surface water is freshened by increased river flows and ice melt near the limit of its northern extent - fresh water is less dense than salty, hindering convection.]
Anyway, there seem to be three cases to consider:
A) The MOC has decreased and will stay weak (or weaken further) in coming years/decades
B) The MOC has decreased but will increase again in the near future
C) The MOC didn't really decrease at all, the measurements (or their analysis) are inaccurate.
I think everyone agrees that case A implies a strong cooling for the UK in the near future. In fact many people have suggested that the reduction, if real, should have already caused some noticeable cooling, given that the decrease is supposed to have happened over the past several decades (half the measured change was in the interval 1957-1992). My money would have to be on case C, but I'm not sure what Bryden and his co-authors think. His paper certainly mentions the possibility of observational inaccuracy, saying that "the observed changes are uncomfortably close to these uncertainties", but follows this immediately with "but [foo] and [bar] represent strong arguments that the observed changes are robust". But although he argues that the MOC really has decreased, he's not prepared to bet that temperatures will drop. I don't think anyone has proposed a plausible argument for the MOC increasing again soon, if it really has decreased (case B), but it seems to be the only option left open to him.
Monday, December 05, 2005
And for the rest of climate science, "sceptic" seems even harder to justify. Sure, I've poked a bit at what I see as one or two excesses from the alarmist wing, but not half as hard as I've kicked at the septics who lie and dissemble and run away when challenged to back up their beliefs with hard cash. It's early days, but I am optimistic that the forthcoming IPCC AR4 will represent a balanced summary of the state of climate science that I will struggle to find much fault with, as the TAR before it did. I would have thought that such a statement pretty well rules me out of the sceptic camp. I'm not sure that "traditionally pro-warming scientist" is quite the best choice of words either, but the intention seems clear.
So if he thinks I'm a sceptic, I wonder what he thinks the mainstream is - Greenpeace, perhaps, or the Monster Raving Green Party?
Sunday, December 04, 2005
Our local bus-stop is beside the shrine Kamakura-gu, which has a good Japanese maple (momiji) outside. Before coming here, I used to think these trees were a miniaturized version of the larger Canadian equivalent. But here they grow into a fair size, albeit slowly. I suppose the ones in the UK are mostly young. Usually we get the bus from here, but it was so bright and sunny that we continued wandering through the back streets towards...
...Hachiman-gu which is Kamakura's most important shrine, where millions (literally) of visitors come at the New Year (quite a sight - the whole town centre is closed to traffic, and the main street from the station is absolutely packed with people). Here's another momiji beside a bridge at one of the shrine's two ponds.
Saturday, December 03, 2005
The first is pension reform. It's long been clear that something had to be done, with people living longer, and no increase in the number of workers (through population growth and/or immigration) necessary to keep them in the style to which they would like to become accustomed. The Govt seems to be heading down the obvious and entirely appropriate path of staged increases in the state pension age, perhaps raising it to 68 by 2050. This in itself won't be quite enough (or indeed acceptable) while they maintain their present unsustainable retirement age of 60 for all public sector employees, but it's always struck me as a stupid waste of ability to throw people out of work at such an early age and I'm sure this will change too (this rule applies to scientists such as me, assuming I return). In fact, it's often even worse than it sounds, because the early retirement packages are attractive to anyone past the age of about 54. Prior to coming to Japan, it seemed like the number of early retirees at my lab substantially outweighed those who survived to full term. For a lab with a budget deficit, it makes some sense (in the short-term) to replace an old expensive employee with a youngster on half the salary. The retiree also gets about half his old salary as pension, but this doesn't come out of the lab budget. So as far as the national economy is concerned, the net result is the same payment for (probably) less good work. But the lab stays afloat to struggle on for another year or two. If this sounds grim, it's because it is :-)
Of course, I'm not against people retiring as early as they want to, so long as they can afford it. Us scientists are certainly lucky to get paid for what sometimes feels like a hobby, and I'm sure that some people don't enjoy their work as much. I don't much fancy 30 years of golf, but I don't discount the possibility that I might feel differently in a few more decades. Anyway, a more gradual wind-down seems more sensible to me than a sudden stop, at whatever age. My father-in-law is still working quite gently in a university department at age 75 - he goes in about one day a week or so, and churned out his 100th paper not long ago (and in fact Jules and I co-authored one of the previous ones, which was fun). That seems like a very civilised approach to retirement. But anyway, I digress.
The other issue which has hit the headlines is the fuss over nuclear power. Many of the UK's existing nuclear power stations are due to close by about 2020, and with the North Sea gas also running out, new nukes is one obvious option. It's not without problems of course - mainly opposition from various environmental groups. I'm certainly not overly keen (it seems to me that the level of funding they seem to require could be usefully applied to research into renewables, which are now close to the point at which they could make a real contribution eg, not that the UK is particuarly well-suited to solar power). Nuclear power should cut CO2 emissions, but perhaps not by as much as one might hope, due to the energy demands of extracting the fuel (plus construction and disposal, I guess).
The point I want to draw from this lengthy ramble is the encouraging fact that the Govt is prepared to take a long-term view - not something that any politicians (and especially the present crop) have often been accused of. 50 years into the future is usually way off the radar and even 2020 is far off. On this time scale, climate change becomes a significant consideration, and it is possible that we will see the meaningful debate that has so far been largely absent. The emissions argument is already being used as a justification for more nuclear power, although it's been said that the possibility of rising sea level may also interfere with using some of the best coastal sites (actually, I find it hard to believe this is really a serious issue given the rate of a few mm per year - note that we have a 6 metre tidal range in some places). I'm not sure if this is Tony Blair trying to create a lasting legacy, or simply not caring about re-election. Either way, I think they deserve some credit for at least being prepared to address the problems, whether or not they choose exactly the solutions that I would prefer. In contrast, here in Japan, the long-anticipated population crash has already started a couple of years ahead of schedule. The population is declining (for the first time ever, near enough) and the proportion of retirees is rocketing. With lifetime fertility now below 1.3 children per female (replacement rate being about 2.1) this is shaping up to be a crisis of epic proportions compared to the UK's relatively stable situation. And what do we have in the way of planning? Occasional giggles in the scandal-sheets over how some naughty politician or other has been caught not paying into the voluntary-compulsory national pension scheme that everyone knows cannot possibly cope with the future demands. As for the pension rights of foreigners - that can only be described as state-sponsored theft, but that rant is for another day.
Friday, December 02, 2005
It's one of a set made by a couple of strange people, featured on this BBC News webpage.
Thanks to my brilliant sister for spotting this. Her Youth Hostel in the Duddon Estuary (on the edge of the English Lake District) is surrounded by dozens of interesting things to see and do, including some very exciting ruins and a nature reserve containing the elusive natterjack toad, which she recently was awarded a "Green Oscar" for looking after.
Thursday, December 01, 2005
I should make it quite clear that I'm not going to be presumptious enough to criticise what they've done - the work looks fine, and they are up-front about their estimated uncertainties in their result. But the press does seem to have gone overboard on what is an interesting, but perhaps slightly anomalous result. Firstly, I would never want it to be thought that I prefer models to measurements - quite the reverse - but such a strong effect seems a bit unlikely, given what is understood about the dynamics. The 30% reduction in overturning circulation that they infer is a realistic estimate of the response to a century or more of substantial future warming, but no model suggests anything of this nature under recent historic conditions. In fact, according to these new figures, all of the slow-down happened prior to 1998, and half of it prior to 1992. Since 1998, things have not changed significantly. Assuming a drift speed of 3cms-1 (feel free to correct this calculation), 10 years represents 10,000km of travel, plenty of time to cover the distance from tropics to UK latitudes. But there hasn't been any significant cooling observed yet in the northern Atlantic, let alone the UK climate.
I also have to say that I'm increasingly jaded about the type of stuff that gets published in Nature. Sure, this is easily (and indeed correctly :-)) dismissed as the bitter and twisted response of someone who's never likely to get published there. But their deliberate policy to select only the most "exciting" results, which are then picked up and amplified by the press, pretty much guarantees that the outliers are given a prominence that substantially overstates their true significance (I'm wondering if I should even draw attention to this again, or if it would be more polite to let it die a natural death). When all the world's climate models predicted a steady modest decline in THC which would only partially offset the future warming, it only rated an unheralded paper in GRL. I don't see this new work in itself as being enough to justify the suggestion that the UK Govt should now start planning for a colder, rather than warmer, future. And talk of a "smoking gun" also seems a bit premature. The uncertainty in the analysis is "uncomfortably close" (their words) to the observed effect, and that's assuming they haven't underestimated their errors, which is always a possibility. But it's certainly interesting, and I look forward to future analyses.
Oh ok, time for a minor nit-pick that I thought of while cycling home. They infer a change of about 8-9Sv which they admit is "uncomfortably close" to the error estimate of 6Sv on each value. But (unless I've misread something) the 6Sv refers to the uncertainty of each value individually, so the error on the difference between two values is 6*sqrt(2) = 8.5Sv. That's a bit more than uncomfortably close to the estimated change, in my book. Set against that, both the recent values are low and both the first two values are high, so I'm not claiming to have completely wiped out their result with a spot of mathematical sleight-of-hand.
I see RC also give a somewhat guarded (and more scientifically detailed) assessment here.
Tuesday, November 29, 2005
Interesting snippet in the Grauniad, which I didn't notice making much impact elsewhere: Keep science off web, says Royal Society. I think this is a terrible idea. Through the internet, information can be shared rapidly and freely. Obviously the peer-review process is valuable, but note that the reviewers themselves don't get paid under the current system anyway! Many journals already charge authors (institutions) for the priviledge of publishing in them. IMO that is a better method of supporting them, than giving them full copyright control and preventing authors from disseminating their work freely. In fact, most journals do allow authors to post their papers on the web anyway - all of my recent papers are available from my web site.
Saturday, November 26, 2005
The introductory talks were all very interesting, which was a pleasant surprise. Not too much of a focus on abstruse details, but a broad exploration of interesting issues well exemplified by Julia Slingo's discussion of the competing demands of complexity vs resolution vs uncertainty. Kimoto-sensei presented some evidence that although increasing resolution doesn't change the broad picture, it strongly affects the ability of the model to represent changes in extremes - in the particular case of rainfall in Japan, this will likely lead to more days with either no rain or extremely heavy rainfall, and fewer with modest rainfall. Observations over the 20th century seem to support these modelled trends.
Then we went on to more detailed modelling, with different people illustrating the effects of focussing on complexity and resolution (not much on uncertainty). The details were certainly interesting but it's not quite my field of research - I'm primarily interested in prediction skill and uncertainty, and the question of deciding what the priorities are (from a modelling POV) for future work is mostly someone else's problem. I was not alone in making the point that exploring feedbacks and processes is not the same thing as improving predictive skill, and it's important to be clear what the specific goals are when new stuff is added to models. There seems to be widespread agreement that increased resolution should certainly help us, since the basic fluid flow equations are well understood (and NWP results are also available as support), but, even though it's been shown that feedbacks due to the ecosystem etc certainly can be important, it's less clear that we understand them well enough that including these sub-models will actually improve the model output.
Jules and I gave our talks on Friday morning - she presented work from our SOLA paper, and I talked about something we did more recently. The latter stirred up a bit of debate, as we had hoped. The last session was about the computer science relating to making large models run efficiently on huge computers - which I'm relieved be able to say is not of much direct importance to me (though I'm glad other people exist to worry about this stuff). We then closed with an interesting discussion about the sort of scientific problems we were hoping to solve, and what sort of models would be necessary to achieve this. There was quite a lot of grumbling at how IPCC deadlines and priorities were forcing people to rush into big modelling efforts and "global warming prediction" at the expense of the underpinning science. It's hard to see a good answer to this - it is only due to the political demands that the science is so heavily funded in the first place, so IMO we can hardly complain if the funding is tied to political demands. OTOH there has to be some room for process-oriented and fundamental reseach without it necessarily having to be justified and presented in terms of the next generation of IPCC results. Does the grumbling indicate a really fundamental problem with the sustainability of climate science and the IPCC process, or is it just the standard cynicism and jockeying for position that can usually be expected from British scientists? Time will tell.
Tuesday, November 22, 2005
Here are a few more UK climate-related acronyms, culled by my mother from a recent English Nature magazine:
ACCELERATES: Assessing Climate Change Effects on Land use and Ecosystems; from Regional Analysis to the European Scale.
AUDACIOUS: Adaptable Urban Drainage - Addressing Changes in Intensity, Occurence and Uncertainty of Stormwater
BESEECH: Building Economic and Social information for Examining the Effects of Climate Change
CRANIUM: Climate change Risk Assessment; New Impact and Uncertainty Methods.
POPPYCOCK: Promoting Oceanic Policy Preparation for Youth Council On Climate Kinetics
Sunday, November 20, 2005
Recently, he sent round a new press release proudly boasting about his success in predicting "Storm 27" in the Caribbean/Gulf area in the time window 13th-16th November. And indeed, on the surface, it looked like there could have been some substance to his claim.
The only problem is that his actual prediction was for "a major Tropical Storm or hurricane", and in fact what he optimistically called "Storm 27" was not a storm at all, let alone a major one or a hurricane, but in fact only a very weak tropical depression which died a few days later. Look here for its history, including wind speed ("DEP" in the type column is a bit of a giveaway).
Here's a picture of its track, with colour-coded wind speed:
For the picky, his original forecast actually said "around the 13-16", and you can be sure that he would have allowed himself a day or two either side if that had been necessary to score a "hit". But since he's already claimed "storm 27" as his validation, I don't think even he could have the chutzpah to claim Tropical Storm Gamma (born on the 18th) instead. I'll email him with the link to this post and maybe he will grace me with a comment.
Friday, November 18, 2005
It's always fun to show round visitors - it gives us a bona-fide excuse to take a few days off and re-visit some of the best sights around here.
Apart from acting the tourist guides, we've also been feverishly scribbling a new paper that we think is fairly important, and which is certainly urgent. I'll wait to see how well-received it is before saying any more about it...
Wednesday, November 16, 2005
So I got to thinking about what day was most likely. It was immediately obvious that it can't be scheduled for the 30th, because if it has not happened before we come into work on that day, we would know it has to happen that afternoon, and therefore it would not be a surprise. But on the morning of the 29th, there would only be two possible days left, and having already ruled out the 30th as impossible, it would have to be the 29th. So there is no surprise there either. Having ruled out the 30th and 29th, it is easy to show that the 28th is similarly impossible. And so on, right back to the 1st. I conclude that we can't have the surprise fire drill at all!
I know you will all be fascinated to hear how things turn out.
Update 16 Nov
Well, it happened today. Was it a surprise? No not really, as someone had already told me it was planned for this day. In fact I made up the story about it being a surprise. But it was only after glancing at the Wikipedia page on the paradox of the unexpected hanging that I found out that this is also known as the paradox of the unexpected fire drill. If you still don't know what I'm talking about then read the page and all will become clear.
Thursday, November 10, 2005
Chris invites me to deride their uselessness vis-a-vis global warming. Sorry, but if our "OLs" (office ladies) wish to walk around in skimpy clothes all winter, I'm not going to object too strongly. And you thought I was here for the higher salary and status, great working conditions, strong infrastructure, academic freedom, lovely climate and fabulous countryside?
More underwear fun can be found here.
Sunday, November 06, 2005
How can we trust climate forecasts 50 and 100 years into the future (that can’t be verified in our lifetime) when they are not able to make shorter seasonal or yearly forecasts that could be verified?This is standard septic drivel that is easily disposed of (and if you want more technical details, my own work demonstrates some ideas about how to do it in practice). Note: this does not in itself prove that the models are right, it merely illustrates why Gray's line of reasoning is garbage. But anyway, this isn't really my main point. You won't find it in his written statement, but in the video of the proceedings, he clearly says:
I predict, now I think I know as much as anybody, I'll take on any scientist in this field to talk about this, I predict in the next 5 or 8 years or so the globe is going to begin to cool as it did in the middle 40's.I emailed him some time asking if he will back up this statement with a bet. William Connolley and Brian Schmidt at least have done the same. None of us (to my knowledge) has had the courtesy of a reply. Given his statement above, I do not believe it is too much to expect that he should at least quantify his prediction in terms of his confidence (what odds he would place on his prediction being provved correct). To not do so seems to be clearly misleading the Senate Committee hearing.
I guess I shouldn't be surprised that something which is so obviously a circus has a few clowns present...
Thursday, November 03, 2005
Following on from the silly gadget of yesterday, today was the national holiday of "Culture Day". Living in Kamakura, most of the culture is of the ancient Buddhist variety (Kamakura was Japan's capital in the Kamakura Era [1185-1333], and a huge number of temples were built around that time). So we wandered over the hill to Kenchoji, which has its annual "airing of the treasures" on this day. We've seen it before so just had a quick look at this friendly dragon painted on the ceiling of one of the halls (whose eyes seem to follow you round the room) and then headed into town.
November - February is oyster season in Japan, so we had some, fried, for lunch. They don't seem to be eaten raw here much, which is odd considering what else does! There's my plate of deep-fried oysters and assorted side-dishes, all to be washed down with a cold beer. Oishiiii!
Walking home takes us through the grounds of Hachimanguu, Kamakura's main shrine. The "7-5-3" festival is going on around now. At this time of year, boys (5 yo) and girls (7,3 yo) get dressed up in kimonos, taken to shrines by their proud parents, and wished luck by the priest for the coming year. All for a suitable fee, of course. The more you pay, the better your luck.
I've just heard that one of our senior members of staff was yesterday presented with "The Orders of the Sacred Treasure" for services to the nation and public (Dr Ninomiya is a former Director-General of the Japan Meterological Agency). This award is one of the 5 Orders of Culture handed out annually on this day. I will resist the temptation to add any comments about him being brought out for public viewing once a year :-)
Wednesday, November 02, 2005
a taxi with a wind-powered mobile phone charger mounted on its roof. Ok, maybe I'm being a bit unfair to Japan. I should also mention that many of the world's coolest gadgets are invented here too (this one is relatively mundane, although still very cool). But putting a wind turbine on a car roof certainly crosses the line between normal and wacky.
It is justified here as a purely promotional exercise to encourage the use of greener energy, which I suppose is fair enough. Some other web coverage seemed to believe that it was a genuine (though small) contribution to reducing carbon emissions, which is a bit worrying. Putting a fan on the roof, thereby increasing drag, just so a small proporrtion of the extra fuel burnt could be converted into electricity, is a bizarre approach to energy efficiency!
Saturday, October 29, 2005
- We use an efficient multivariate parameter estimation method with a state-of-the-art GCM for the first time. This is many many orders of magnitude more efficient than multifactorial sampling, and several people have told us over the last couple of years that it couldn't be done. (I won't deny it has some potential drawbacks, though - but we haven't found any show-stoppers).
- We have tried to take some account of model inadequacy - by which I mean the fact that there are no "correct" parameters for which the model actually looks just like the real world, so the standard "perfect model assumption" is wrong.
- We have used out-of-sample data (in this example, a simulation of the Last Glacial Maximum) to attempt to improve the rigour with which predictive skill is assessed. Merely managing to fit a set of data doesn't automatically mean that the model will skillfully predict climate under a different forcing!
Oh, by the way, we didn't really learn anything startling about climate sensitivity. But we all know that's about 3C anyway :-)
Sunday, October 23, 2005
One winner is usually a top-notch scientist in the traditional mold (past winners include Wally Broeker, Suki Manabe, Robert May) and the other more of an activist or politician (Vo Quy, Gro Harlem Brundtland, various worthy organisations I may have vaguely heard of). This year, Nick Shackleton and Gordon Hisashi Sato were the joint winners. They talked at some length about their work, which was very interesting, but then both ended with rather incongruous calls to cut CO2 emissions. The sentiment may be well-meaning but it all seemed a bit odd.
However, their comments were nowhere near as odd as the introductory film we were shown for the first time this year, which consisted of pictures of war, devastation, pestilence and natural beauty all overlaid with an inane voice-over asking cheesy things like "Why are we killing Mother Earth". It would have been rude to laugh out loud, but I couldn't suppress the odd snigger.
I hope they received enough negative feedback that next time they'll revert to just having the talks!
Saturday, October 22, 2005
Markets have now been shown to out-perform collections of "experts" in predicting monthly economic data better than the best economists, or in accurately forecasting whether WMD would be found in Iraq. Mathematicians believe that the existence of a market allows large numbers of people effectively to "pool" their collective wisdom, with each new trader able to bring a unique new insight into the mix.
How can this power be harnessed for the social good? Iowa has recently been experimenting with the trading of "flu predictions", in which traders have been asked to forecast the state of flu alert that will be in place in the state several weeks in advance. Researchers have found that the flu prediction market has been able to predict the state of flu alert with 90% accuracy a fortnight ahead of time - long enough to allow medical staff to gear up prevention and treatment regimes. Iowa economists will next turn their attention to a market that will predict the number of bird flu cases in the US. It cannot come soon enough.
Tuesday, October 18, 2005
The issue the shadowing lemma addresses is this: given a set of differential equations which describe a chaotic system (such as the Lorenz equations), we have no way of calculating a true trajectory, since all of our numerical methods make various approximations (such as using the finite difference (x(t+Dt)-x(t))/Dt in place of the true derivative dx/dt, for example). Moreover, digital computers only calculate and store results to finite precision, so there are rounding errors at every step. In a chaotic system, these errors will grow exponentially and so the model's trajectory (when initialised from a particular state) will differ wildly from the exact system. So what can we hope to learn from the model?
The shadowing lemma provides a very encouraging answer to this problem. It assures us that, although the true system does not track the model's output when they are initialised from the same starting point, there is a trajectory of the true system (starting from a slightly perturbed initial state) that stays close to the model for an arbitrary length of time. So the model output does in fact "look like" a trajectory of the system after all. The pdf file linked from here is one of the most accessible descriptions I've found on the web (the "hyperbolic system" it refers to is a technical term which includes the standard chaotic systems of classical physics).
Stoat has a nice set of graphs showing the growth of small perturbations in the HADAM3 model (atmosphere component of the HADCM3 atmosphere-ocean GCM). As I mentioned in the comments to his post, I am a little suspicious that a small local perturbation can kick off differences across the whole globe within a day or so. Note that the "model physics" does not support pressure (sound) waves so information should only propagate at around the speed of the flow. It seems likely that the propagation speed in these experiments is instead a numerically-determined rate of one grid box per time step. Fortunately, the shadowing lemma comes to the rescue here. Although the perturbation he used would probably not grow in this way given a numerically precise solution to the fundamental equations, the shadowing lemma tells us that there is a true trajectory of the exact system which looks similar to each model run, and therefore their two sets of initial conditions form a (control,perturbed) pair whose difference really does grow as the plots show. Their initial difference would necessarily be small in magnitude, but I expect it would be globally dispersed in nature.
Now, Professor Eykholt made repeated reference to the shadowing lemma in his emails to me, which you can read on Roger Pielke's blog. (I'm amused to note that they're both happy to publish my email without bothering to ask, which rather puts Eykholt's "totally unethical" accusation into context). I struggled to find a way of interpreting his first comments so as to be somewhat relevant, and I can see now how I misunderstood them as a result. However, given that the shadowing lemma only applies to chaotic systems in the first place, it seems bizarre to attempt to use it to demonstrate that a system is not chaotic. In fact, on re-reading his emails his line of argument appears very strange indeed. It is precisely the shadowing lemma that tells us that there are initially-close trajectories of the real system which diverge in the way that the numerical trajectories do, as per the discussion of HADAM3 above. I cannot see how his statement "The shadowing lemma gives you a scale beyond which small perturbations cease to have any important effects" can be reconciled with what is generally understood about chaotic systems. Unfortunately, he refuses to communicate any further on the matter, so I'll never get to the bottom of what he is thinking.
Saturday, October 15, 2005
The butterfly effect refers to the exponential growth of any small perturbation.So I am now more puzzled than ever as to what he really means. I've asked him and Roger if they can supply any theoretical or practical support for Roger's claim that below a certain size, small pertubations fail to affect chaotic systems (at least, the atmosphere in particular)...
Ok, on re-reading Prof Eykholt's emails, I can now see how I misinterpreted them, and I'm sorry for any confusion I have caused. In my defence, I did email him back to check that I had understood his point correctly (he explicitly invited me to do so) last Thursday, and never received a reply. I still think that my comments on chaos are entirely uncontroversial and in line with the overwhelming maority of the field. Prof Eykholt's emails to me lean heavily on the Shadowing Lemma, so I'll probably do a post about this shortly, explaining its relevance (or otherwise) to the debate.
Friday, October 14, 2005
"The point of the [exponential growth of minuscule perturbations] effect is that it prevents us from making very detailed predictions at very small scales, but it does not have a significant effect at larger scales."which RPSnr takes as vindication of his claim that small perturbations do not affect the real world, only models.
The quotation seemed a bit unclear, and RPSnr's position is clearly wrong, so I emailed Prof Eykholt to see what he really meant. He explained that he was referring to issues of practical prediction, in which case any additional perturbation of a similar size to the rounding error of a finite precision computer model cannot harm predictability over broad spatial scales, since the model already has lots of perturbations of equal size (not to mention more substantial errors) which limit predictability. Of course this is true (to the point of triviality), but it hardly seems relevant to RPSnr's claims. Further, Prof Eykholt explicitly agreed that a small random perturbation in a chaotic system will grow to a point at which the original and unperturbed systems are completely decorrelated.
Meanwhile, back in the comments section of his post, RPSnr seems so determined to defend his untenable position that he is now claiming that not only turbulent energy but even momentum itself will dissipate in the real world...
Monday, October 10, 2005
Less widely-known than Lorenz's work is the fact that the chaotic dynamics of the 3-body problem had been shown much earlier by Poincare. Following the links on wikipedia (and googling) should cover the historical and technical background adequately.
The significance of chaos to weather prediction is sometimes overstated - the existence of a Lyapunov (watch the spelling, wmc!) exponent of > 1 does not in itself preclude accurate long-term predictions, since it relates only to infinitesimal perturbations integrated over infinite time (note that we are staying in the realm of mathematics and classical Newtonian physics here - I'm not going to start talking about molecular and quantized effects). In realistic applications, it is the current (and near-future) growth rate of finite perturbations that is more important, and this may well be negligible or negative over significant periods of time. And even that ignores the effect of model error, which means that even a perfectly initialised model state will inevitably diverge from truth over coming days. Some analysis of weather prediction I've seen indicates that model error is a substantial source of forecast error, with chaos relatively unimportant. But this is not my current field of interest, and this is also probably getting a bit obscure...
Anyway, the point is that a random perturbation will have a non-zero projection onto Lyapunov vectors with exponents greater than 1 (ie, growing vectors). In the atmosphere and many other chaotic systems, most of the perturbation will project onto decaying vectors, so overall it will initially shrink. However, ultimately the growing component will come to dominate and the pertubation will grow (with probability 1).
This is the sort of thing that is easy to show with numerical models of the atmosphere. Simply perturb a reference run, and see what happens. There are a couple of "gotchas" that could confuse the results. Firstly, limited numerical precision means that a small pertubation could fall below the level of numerical precision and be rounded out of the system. This is demonstrated by running the model at diffferent precisions. A perhaps more subtle problem is that many codes contain max and min operators, to prevent nonphysical solutions (eg turbulent energy is not allowed to fall below a threshold, velocities may be limited for computational reasons). If a variable crosses such a threshold and is reset to the limit, then a slightly perturbed version will be reset to the same point and again the perturbation is lost. But these are nit-picks in a result that is otherwise robust across all adequately realistic models. It is possible in theory to devise a perturbation that shrinks even without relying on these factors (align it precisely with only the shrinking LV), but a random pertubation will not have this property. Of course the existence of an unknown butterfly flapping its wings has no direct bearing on weather forecasts, since it will take far too long for such a small pertubation to grow to a significant size - if it affects the weather 100 years from now, this will be obvious in the atmospheric state 99 years and 51 weeks hence, and so will be accounted for in the forecast.
I might as well point out again here that the chaotic sensitivity of a system has no direct bearing on forecasting the climate (ie the long-term statistics) of the system. To copy from my comment on realclimate:
Not only is the climate of the Lorenz model easy to understand, it is also simple to predict how it will respond to a variety of "external forcings", in the form of either a parameter perturbation or direct forcing term in the dynamical equations. Eg see here and here. However the detailed trajectory is unpredictable except in the very short term.
Anyway, this is all pretty well-known stuff - or so I thought, before reading Roger Pielke Sr's blog. He seems to deny that this "butterfly effect" exists at all. Myself, Gavin and William have all pulled him up on it, so it will be interesting to see how he justifies this in his promised follow-up post.
Sunday, October 09, 2005
Thursday, September 29, 2005
Gavin Schmidt and Michael Mann comment on this and other aspects of the hearing on Realclimate. I feel I should gently point out that they have rather missed the point in their suggestion that
This would appear to be a direct call to those "global warmers" (see also here, here and here) who are trying to get contrarians to put their money where their mouths are (with very limited success).Bill Gray's comments are a challenge to all mainstream climate scientists who agree that the dominant cause of the recent warming is anthropogenic and ongoing. I might take up Gray's offer, but I'm really more interested in what the wider consensus is - I don't need to make bets to work out my viewpoint!
So, I'm probably going to sit back and wait for a while to see how many others are prepared to join the fray...
Wednesday, September 28, 2005
I only hope that he doesn't attract any climate septics. There are already several people lined up with offers on the table that should be attractive to any honest sceptic, and I'm sure they would happily accept odds more strongly in their favour should anyone really want to make a splash!
Thanks to Chris Masse for the tip.
Friday, September 23, 2005
Piers did eventually comment on my blog article (in the comments section here). I emailed him the reply which I posted below his comment, but have not heard from him again. Since he doesn't seem willing to communicate with me, I alerted William Connolley (WMC) to his offer to bet. WMC emailed him and did initially get a vague reply, which appeared to show interest, but did not address the specifics of a bet. WMC has emailed him several times over the past month, offering either to duplicate my existing bet with Bashkirtsev and Mashnich, or alternatively to negotiate something else along similar lines, but Piers has studiously avoided a direct response. He did refer to my blog article as "deceitful" and "libellous", but as far as I can see, all I have done is accuse him of ducking the challenge, and this seems to be a fair summary of the current state of play. Of course I'll be happy to help publicise any bet if only he would agree to one.
I remind all sceptics that there are offers on the table of up to 3:1 odds, depending on details such as the duration of the bet. That bookends the "market consensus" at between 2% and 25% (the lower figure referring to Lindzen's 50:1 offer). That's still quite a range (and I hope it will narrow further), but the important point, which underlies the whole "betting market" concept, is that this estimate explicitly accounts for the opinions of the sceptics. If anyone wants to take up any of these offers, or make a better one, please let me and/or the bet originators know.
Sunday, September 18, 2005
In case it gets changed, the version I'm referring to is the one archived here. No, I'm not going to bother adding to or editing it - pages about me and my work are already available from the links at the RHS of this page. And anyway, it's not far from the truth :-)
Saturday, September 17, 2005
It should give pause for thought for all those trying to excuse the killing of Jean Charles de Menezes. "Just one of these things" or a pattern of violent disregard for minimally acceptable standards of human behaviour, especially when the victim is black?
Wednesday, September 14, 2005
Most of the chasing has been done by William Connolley and Brian Schmidt. In the aftermath of my bet being announced, various pundits boldly claimed that they would be willing to take the "cold" side of a bet on the same terms or similar. Chris Randles quickly took one of them on for 500 pounds, which I reported here. However, subsequent attempts to chase down the others have so far proved fruitless.
Brian Schmidt tried here, with no response so far.
William Connolley has tried to get something out of "I'm happy to bet loads of money" Piers Corbyn, but nothing's been arranged yet. He's also emailed Tim Haab and I wait to see what, if anything, transpires.
Lubos Motl made a rather childish offer that he would accept odds of 8:1 in his favour on a 10 year bet, but only so long as it used only a single year of data at each end. Of course, this makes the temperature change very noisy due to interannual variability, as you can see on the graph below:
Here I've plotted the NASA GISTEMP annual temperature anomalies, and a 5-year smoothed version (both offset by 1C). The decadal temperature changes are shown below that, with the zero line indicated. As you can see, there have been two occasions in recent decades (three if you go back as far as 1976-1966) when the 10-year change has been briefly negative even during a period which has seen strong warming. William Connolley gets a similar result using a different data set. So Motl's 8:1 offer is roughly a fair bet even under conditions of continued strong warming - hardly a sceptical viewpoint. With a 5-year smoothing filter, the cooling peaks are eliminated, but he wasn't prepared to negotiate on such a bet.
An analytical look at the data gives a similar result. The annual temperatures have a variability of about 0.09C about the trend, which means that a straight decadal difference has a variability of 1.41*0.09C = 0.13C. The trend itself is about 0.17C, which implies that under the assumption of continued warming, the overall decadal temperature change is (roughly) a sample from the Gaussian distribution N(0.17,0.13) which has a 10% chance of being negative. Smoothing substantially reduces the variability - under the (perhaps slightly questionable) assumption that the temperature anomalies of consecutive years are independent, the distribution would be close to N(0.17,0.06) which has less than 1% chance of being negative.
So, no new bets yet. But both Brian and William have now offered significantly better odds than I had to, in the hope that this might tempt some of the sceptics who merely claim that future temperature change is no more likely to be up than down, as opposed to my opponents (and Piers Corbyn) who confidently predicted that cooling was imminent. William has offered 7:3 for an unsmoothed decadal difference. Brian has offered 2:1 on decadal bet, and 3:1 over 20 years. Until and unless they find any opponents, it seems reasonable to conclude that whatever the market rate is, it is higher than those offers on the table.
Tuesday, September 13, 2005
From the English Nature Press release:
Phil Webster and Helen Annan became unofficial wardens of the nature reserve next door to the youth hostel they manage and their infectious enthusiasm helped found a Friends group. This year hundreds of natterjack toadlets emerged – an enormous success for a vital species.Their hostel, in Millom, Cumbria, is right on the edge of the Lake District, surrounded by a mix of stunning coastal and mountain scenery, and with a number of significant nature reserves nearby. You can listen to the rare natterjack toad on their website.
As all Brits and Aussies will have worked out (and probably no-one else), this is a post about cricket, which has always been my favourite sport (probably because it's the only one I was any good at when I was at school). After an epic battle between the two best sides in world cricket (which you can read all about here), England have won the Ashes for the first time in 16 years. The past two months have seen a gripping contest between the long-time champions of Australia, and a resurgent England team who have swept all before them over the past couple of years. And I've spent many long evenings listening to the commentary on TMS. After losing the first Test match to go 0-1 down, England fought back brilliantly to a 2-1 lead (including one of the best test matches ever), and so were left only needing a draw in the final Test. For the past 5 days they have been doing their best to withstand everthing the Aussies could throw at them, and eventually the whole summer rested on the final day's play. Nervously at first, then with increasing confidence and finally with exuberance (Kevin Pietersen's 7 sixes being the most in an innings in any Ashes Test), they weathered the storm and battled to safety and the series win.
Most of the Australian team looked a bit past their best, and their two star bowlers (including the fat spinner featured in the title, Shane Warne) are in the twilight of their careers. England, on the other hand, are young and several of them should have their best years yet to come. It would be foolish to predict a decade of world domination, but they certainly have no-one to fear.