Friday, December 28, 2007

Chylek on sensitivity

Another one of this strange collection of papers has an odd attempt to estimate climate sensitivity by Chylek et al, which has recently been published.

They start from the familiar zero-dimensional energy balance

(1) dH/dt = F - l.T

where H is the total heat anomaly (dominated by ocean heat uptake), F is the forcing anomaly and T the surface temperature anomaly (note that my notation is slightly different from theirs). Here l = 1/S is the radiative feedback parameter, the inverse of climate sensitivity S. At equilibrium, the LHS of equation (1) is zero and so the formula T = F/l gives the equilibrium temperature change for a given forcing.

Chylek cites Raper et al (2002) to justify the substitution

(2) dH/dt = k.T

where k is a constant. This is slightly different from the "effective heat capacity" approach of Schwartz: in this expression, the rate of heat uptake is assumed proportional to the surface temperature anomaly, whereas for Schwartz, the heat content is assumed proportional to surface temp anomaly - with heat content being the integral of heat uptake over time. This expression that Chylek uses may be a reasonable approximation during an experiment in which the forcing is increasing steadily (as Raper et al state), but is clearly not valid in general, as we shall see shortly. (For reference, Raper et al apply their analysis to the standard test case in which the CO2 level increases at 1% per year and all other forcing are held fixed.)

Substituting (2) in (1), we get

(3) k.T = F - l.T

which can be differentiated (or finite-differenced) with respect to time to get

(4) k.DT = DF - l.DT

where the D indicates the decadal trend (it's a greek Delta in Chylek et al).

This can be rearranged to give

(5) S = 1/l = DT/(DF - k.DT)

which is the expression that Chylek use to diagnose S using data from the past decade.

But it is immediately obvious that this expression will have some problems when used to diagnose S over an arbitrary interval. For example, if we take a decade over which the net forcing does not change, then DF = 0 and from equation (5) we get

(6) S = DT/(0 - k.DT) = -1/k

unless DT is also zero (in which case the expression is undefined) which is implausible to say the least. So something odd is going on here. Let's look a little closer...

Stepping back to equation (3), we can rearrange it to give:

(7) T = F/(l+k)

which implies that (in order for the equation to be valid) the surface temperature must always be directly proportional to the forcing - with constant of proportionality 1/(l+k) - and thus is instantaneously in equilibrium with the forcing, with no lag.

However, we started off with the zero-dimensional energy balance (1) which as I already pointed out has the equilibrium solution

(8) T = F/l

These latter two expressions (7) and (8) are only compatible if k=0 (which it certainly isn't, and Chylek never claim it is).

So we have a contradiction here. The fundamental problem is that the expression dH/dt = k.T is only a plausible approximation under certain circumstances. Chylek's formula (5) cannot be used as a general expression to diagnose the sensitivity of the climate system, as it gives nonsensical answers when forcing does not follow a steadily-increasing profile such as that of the CMIP (1% pa) experiments. There is no justification in their paper as to why their expression should be accurate when applied over the last decade, and I'd bet dollars to doughnuts that it fails to usefully diagnose sensitivity when applied to GCM output such as that in the AR4 database (I've not bothered to do this).

So in the absence of any evidence that their method actually works, it's hard to take their results seriously. I haven't even started to talk about how sensitive their calculation is to natural variability noise, which they have not accounted for either.

Wednesday, December 26, 2007

When is a democracy not a democracy?

When half the ruling party (and 8 out of 10 recent prime ministers) have inherited their seats:
After the last election, 185 of 480 Diet members (39 percent) were second- or third- (or more) generation politicians ('seshuu seijika'). Of 244 members of the LDP (the ruling party for practically the entire postwar period), 126 (52 percent) are seshuu seijika. Likewise eight of the last 10 prime ministers, and around half the Shinzo Abe and Yasuo Fukuda Cabinets. When the average turnover of lawmakers per election is only around 3 percent, you have what can only be termed a political class.
Debito is a bit in-your-face but rarely significantly wrong in his facts, so I see no reason to doubt these figures. I'd be interested to hear of equivalent stats for other countries. I know that in the UK "Fatty" Soames is related to Churchill, for example. And of course the USA has its dynasties of Bushes, Kennedys and Clintons (although perhaps the last ones were both destined for politics before they got together). There's a Mussolini in Italy, but I can't help but think that the fame of these few cases may be a sign of their relative rarity.

Correspondents say the law will deal a blow to themed resorts across the world where large-scale copies of Egyptian artefacts are a crowd-puller.
This correspondent says the law is a joke or political stunt that will have no effect outside Egypt's borders. Obviously.

Hmm...on the other hand, maybe the Scottish parliament should charge worldwide royalties for users of pneumatic tyres, tarmac roads, televisions, bicycles, penicillin, and deep-fried Mars Bars...they'd probably have to go halves with Italy on deep-fried pizza though.

Tuesday, December 25, 2007

A Christmas Poem

Just thought I'd like to share this, from a collection of Christmas poems:
`Peace upon earth' was said. We sing it,
And pay a million priests to bring it.
After two thousand years of mass,
We've got as far as poison gas.
That was "Christmas: 1924" by Thomas Hardy. Happy turkey-stuffing to you all.

Sunday, December 23, 2007

AGU: the science

OK, enough joking around. I was actually there for work, having received a generous invitation to present at the session on "Climate Sensitivity From Modeling, Current Observations, and Paleoclimate Data."

We've often thought about going to the AGU Fall Meeting, since while we are in Japan it's actually more convenient than the EGU, but never previously got round to it. The organisation is rather different to the EGU, and took a bit of getting used to. For some reason, the poster sessions are not clearly linked to their corresponding oral sessions (the code numbers indicate the section and the time, but eg there is no obvious link between U43A and U51B, despite them being posters and oral session on the same topic). They don't even arrange things in alphabetical order in the book. There is also no Climate section and very little Nonlinear Geophysics (the two most interesting sections in the EGU), but a whole lot of Paleoclimate.

Here are some highlights from my notes. Errors and omissions all mine, of course.

After a couple of paleoclimate talks first thing on Monday morning I ducked into a rather bizarre session entitled "Navigating a Career in the Geosciences: Strategies for Success." It started off with some important successful guy telling us how the rewards would come if we just put in enough hard work and perseverance and were prepared to take our chances. He told us his own life story of how there were not enough jobs in his PhD speciality, so he changed topics. Then he found funding hard to come by in his next field...so he changed again, becoming Director of NCAR. Why didn't we all think of that? The next presentation was a similar pep-talk from another senior professor about how great life was if only one persevered, but the last talk actually did have some useful content based on real research about what distinguishes the more successful from the less. But I'm hardly going to give away the secrets to you lot :-) One of the most important factors seemed to be the Y chromosome, which reliably distinguishes the "outstanding" from the merely "hard working" (Trix and Psenka, 2003). Later on that day, a session on extremes had Tom Knutson sounding rather sceptical about whether or not hurricanes were likely to increase much (and he thought it would take some time to see a signal in the data).

Tuesday morning started with a session on aerosols, not really my thing but I'd spotted both Schwartz and Chylek were presenting, so I turned up to listen. Steve Schwartz presented his sensitivity analysis, but admitted it had received a lot of criticism and he would not "bet the ranch" on it, which probably defused some potential criticisms (in the questions after someone did say that they thought his detrending was a dodgy step). Later on in the week I spoke to him in person, he said he'd just got our comment and hadn't yet planned his reply. Petr Chylek presented a somewhat similar paper from in the same special issue of JGR (guest editor: P Chylek) which I'll probably blog about in more detail later. I got the impression of a bit of a clique separate from mainstream climate science here. Someone in the audience actually asked where they might get the opposing point of view. It wasn't 100% clear what they meant by "opposing", but one good answer might be chapters 9 and 10 of the IPCC AR4 WG1, or indeed the whole book. There was also a session concerning use of the multimodel ensemble (ie the AR4 runs), which I am getting interested in. In fact there were a few sessions with this sort of flavour that during the week.

After 2 consecutive 10h days and fairly late nights, Wednesday morning had nothing much of interest so we had a lie-in (and tested the crappy hotel gym). The afternoon had some stuff on ocean tracers, including some adjustments to the ocean heat content data, and also estimates of ocean mixing based on various other tracers (tritium from bombs, helium from the mantle). This is something I've tried to point out to some climate sensitivity estimation people who claim that we can't say much about the ocean mixing rate (and thus heat uptake, which affects climate sensitivity estimates) because the temperature data are so uncertain. Even if the direct measurements of temperature are uncertain, we have other evidence about the mixing rate, which they studiously choose to ignore!

Thursday morning had some fun stuff on carbon sequestration, including various air capture schemes. I'm not really convinced that these make sense, but I've nothing against their consideration. Rather than harvesting and burying biomass, it might be simpler to just use it for energy in place of the fossil fuels. In the afternoon we had the exciting session on "Tipping points", which started off with a well-attended talk by Jim Hansen. He didn't actually talk about tipping points in much detail but argued for a rapid halt to coal use (unless sequestration-enabled).

Friday morning was our big thrill of the week, with presentations in the session on climate sensitivity. I was due to talk 2nd up, immediately after Jim Hansen, which (as is generally the case in these situations) I presumed would mean a mass exodus throughout my talk. I consoled myself with the thought that at least most would hear the start of it. Anyway, we arrived bright and early, checked that our presentations were set up and bagged good seats. At about 8:02 the convenor stood up, and said that she was very very sorry, but unfortunately Jim Hansen's presentation wasn't ready yet, so we would have to start with the 2nd presentation! Well at least that saved me another 15 minutes of nerves, and since Hansen's presentation was "in the pipeline" people didn't have time to run out for a coffee so I had a packed house. When initially invited, I'd really planned to steal jules' paleo work and talk about that, but then she also got a talking slot in the same session so I had to leave that in her hands and revamped the "Can we believe in high climate sensitivity" stuff instead. I had some fun reading a bit of Steven Goodman's Nature letter ("This technique would be a wonderful contribution to science were it not based on a patently fallacious argument, almost as old as probability itself") against a back-drop of quotes from the recent climate science literature all claiming that uniform priors represent a state of pure ignorance (this of course being the patently fallacious argument Goodman was ridiculing). Lest anyone think I was picking on anyone in particular, I quoted from 3 papers from largely different groups, plus an extract from the Nobel-winning consensus of 2500 climate scientists otherwise known as the IPCC AR4. However I had noticed that Myles Allen was supposed to be talking straight after me, and I was disappointed that he did not attend and defend his beliefs. I guess if I keep on turning up to the major conferences we can't continue to miss each other indefinitely. The rest of the session had a mix of old and new stuff, nothing too revolutionary. We wound down with a session on geoengineering which was fun.

Nameable names that I met for the first time (mostly very briefly) included, in no particular order: Steve Schwartz, Ray Pierrehumbert, Michael Tobis, Michael Mann and of course there were numerous others I've met before. The weather was great and SF is easily the nicest city I've visited in the USA (not that I'm very well travelled over there) so we thoroughly enjoyed ourselves. On scientific grounds, I think I prefer the EGU, but maybe that is partly a matter of familiarity.

Friday, December 21, 2007

sci-wimmin

Apparently women scientists are all very very unhappy. James pointed me to the "I am woman I do science and I'm not telling you my name" blogs. I even subscribed to one. But I'm giving it up. I find it boring. I'm not sure if it's the anonymity or the boasting about how great their science is that bores me most. Or is it really that I just don't share any of their experiences?

As far as I can make out they all live in countries which actually have anti-discrimination laws, where many women can have careers, by which I mean not just a job with no prospects where they are treated basically as slave labour and blamed for everything which goes wrong. In fact it seems that in their countries any women with a degree can expect to have some sort of career! wow!

I was really starting to wonder how can they bear to almost everyday write another post about every perceived unfairness in their lives when I came across this post.

And it was at that point I realised that for the last 6 years I have been living their dream. I'm not very girly by nature. Once a year I go away to the "Women's Conference" at Amagi Sanso to see what women are like. I really enjoy that, especially since it is only 2 days long. Americans are so noisy! :-) My status here is foreigner first and woman, well - I don't really count as one of them at all. Luckily. Women in Japan get a really bad deal. Here I am treated equally with James. This was not how it was in the UK, but to be honest I think their problem was more that they liked to put all their workers into little boxes ... and the memory is fading.

Everyone here takes my scientific opinion as seriously as anyone else's - actually more seriously in some ways, because I'm a Westerner. And yes, all you girls, who so sadly have never experienced this, it's great. After a while you start to get less angry, less shrill, and to take people as you find them. You start to think before you speak because you realise that when you speak people will listen and act! That bit is a real shock the first few 100 times it happens. So, bloggy sci-wimmin with side degrees in wimmin's stuff, please come to Japan - Japan seriously needs feminism! Well I think it does - the Japanese female workforce is seriously under-employed, and by the same token the men are employed above their natural station. I tried pointing out to my female friends that Japan is 91st in the world in male-female equality but they didn't seem to react at all to the news... which was very puzzling. Bring in the pros!

jules

Wednesday, December 19, 2007

A puzzle

Here's something to keep you amused while I compose my summary of the AGU. It's from one of the presentations I attended.

The left hand side shows global mean surface temperature from an 800 year integration of a well-known climate model (click on the pic for a larger version). The puzzle is to identify what the colour changes represent, and what caused the climate change. The right hand pic (from the IPCC AR4) is simply to provide some context on the vertical scale, it has no direct relevance to the puzzle - note the horizontal scales aren't the same either.

Those who actually know the answer are invited to not answer too soon, so others can have the fun of trying to work it out.

Tuesday, December 18, 2007

The AGU report

We set off on Saturday afternoon, arriving early the same morning in San Francisco. After checking in at the hotel, we stumbled around town trying to ward off sleep for as long as possible.

We had the one disastrous culinary experience of the week, a truly awful sandwich in Lefty O'Doul's just off Union Square - a monstrous wedge of cold, virtually raw (and definitely unchewable) beef between a couple of doorstops of bread made soggy with a smear of cold gravy (to be fair, my pastrami, beans and mash was just about ok, but still rather tepid). Things could only get better...and after a ride home on the California Street cable car, they did, with a tasty snack in the hotel restaurant before an early night.

On Sunday, we found a tandem to rent on Fisherman's Wharf - nothing special, but perfectly serviceable and just about large enough for me. So we cycled over the Golden Gate bridge in brilliant sunshine, and caught a ferry back after an ice cream in Sausalito.

What a great way to spend a sunny day in San Francisco. Monday night's treat was dinner in the much-hyped "Slanted Door" restaurant - it was good, but probably not really worth all the fuss. Tuesday featured a few beers in the Thirsty Bear followed by a curry with a group of friends. On Wednesday we were back in the TB for lunch, crashing a private Texas University party (no, we were invited by mt, honest) and then off to the circus in the evening. We were going to get a taxi there, but Dan decided we should travel in style and flagged down a stretch limo instead.

On Thursday we had a quiet night back at the hotel, in preparation for an early start on Friday - did I mention we were at a conference? - and on Friday afternoon we celebrated the end of the week with another trip to the Thirsty Bear followed by a rather good Asian-stylee "fusion" meal at a nearby restaurant. You might notice a bit of a theme here in our choice of watering hole - we were a little disappointed in the local beer, which (as it had recently in Colorado/Utah) mostly seemed about on a par with my mediocre home-brew, but the Thirsty Bear was exceptional.

Saturday saw us enjoying 12h of stress positions in a Japanese-sized airplane seat (would be illegal in Guantanamo Bay) which made the trip feel like 29h but we eventually got back to Japan by Sunday afternoon.

Overall it was a fun trip, I'm not sure whether we'll be back next time but San Francisco is a great place to visit. I'll not fly ANA though if I can help it. Many carriers these days sell the exit row seats for a modest premium, and sometimes I get one for free if I turn up early enough and ask nicely. ANA just sat random midgets in them, even though their feet barely reached the ground. The food was awful, and they even woke us up a full 3h before landing. On an 8h flight that doesn't leave much time to sleep!

(We managed to fit in some science too, which will follow...)

Friday, December 07, 2007

That Bali Declaration in full

1. We're stuffed
2. Er...that's it
3. See 1.

For the longer version, see here. It's perhaps as interesting for who hasn't signed, as for who has. I know climate science is western-dominated as a field, but it is slightly surprising to me that the organisers did not make more effort to reach out globally - I count a total of 2 Indian signatories, zero Chinese, and 2 Japanese (oceanography types whose names I do not recognise - I'm sure that reflects more on me than them). One Indonesian rounds out the Asian contingent.

In contrast, there are 7 Canadians, 10 Swiss, 11 Norwegians. Yes, there are more than twice as many signatories from the global powerhouse of Norway (population: 5 million) as there are from the entirety of Asia (population: 3.7 billion). I'm not going to start counting the French and USAian signatories. They even found someone from the Faroe Islands and three Belgians (do you know three Belgians?)!

I want one

Well, I don't quite want one like this, but I can see a time in the future when they are a practical proposition. It's encouraging to see people are actually developing these things commercially (as opposed to the odd home-brew like this). Of course for scientific meetings the ideal would be to rent one in-situ rather than own your own and post it around the world.

Meanwhile, the AGU is offering a handful (only) of presentations from the upcoming meeting on webcast (see here), and Nature is doing something on Second Life to coincide with Bali. I can't see the latter catching on - the only reason the bureaucrats have international meetings at all is so they can go somewhere exotic (I'll eat my hat when the UN has a conference in Scunthorpe or Wigan). JAMSTEC has a "booth" there, apparently (Bali, not Scunthorpe). Pity the poor sods who have to man it...not. Not that I'm in a position to throw stones, heading off to the AGU tomorrow. Honestly, I would pay good money to avoid travelling there in person if there was a viable web-based solution.

Tuesday, December 04, 2007

Another bet on (not so much) climate change

Brian has already blogged the details. and so has William. All three of us are joining forces to oppose Joe Romm's claim that the Arctic will be essentially ice free (down to 10% of the historical mean minimum) by 2020.

Brian originally bravely offered to stake a spare button and an old stick of part-chewed gum. William offered up \$500, and I suggested \$1000. At this point, Brian decided he could be a bit braver and Joe started to sound a bit lukewarm. In the end we agreed to evenly share \$1000. It is interesting to observe, and experience, how the contemplation of putting down hard cash (even if not very much) focusses the mind!

I don't even have a strong view on the short-term fate of Arctic ice. But for that reason, I think it is unreasonable to claim that all the models and research (which suggests ice-free around mid-century and perhaps later) is badly wrong. I wasn't planning this as a deliberate hedge, but I certainly don't think I can lose both this bet and the original warming v cooling one.

The gathering storm

Piers Corbyn, 12 November:
At Weather Action we are forecasting at the frontiers of Sun-Earth weather and climate science and are 90% confident there will be a major storm in the period 24th-28th November and the public should be warned and preparations made. The main threat to Holland, as before, is sea defences which will be under attack from the North Storm Surge we predict - and the next one is likely to be worse than the last one.
(the blue ink is his)

Piers Corbyn, 15 November:
To The Secretary of State for Environment, Food and Rural Affairs Rt Hon Mr Hilary Benn MP

Dear Hilary,

Long range severe weather warning for UK storms in period 23rd –26/27th November 2007

Further to the letter I sent at the end of October warning of impending dangerous storms – including explicit warning of threats to sea defences (especially in view of new and full moon high tides at the same times) and tornado type developments in the periods 8th-13th November and 24th-28th November I am writing with an update which can help you prepare via COBR (Cabinet Office Briefing Room) for potentially dangerous severe weather which is likely to hit the UK in the period 23rd to 26/27th November (slightly earlier timing).

[...]

Given recent confirmation of expected developments in Sun-Earth relations we are now over 90% confident that there will be major damaging storm(s) including serious risk of breaches of sea defences* in a number of parts of the UK in the period 23rd to 26/27th November and therefore it is in the public interest for those involved in Emergency Services - and the public - to be given maximum advance warning. We make this information freely available in the public interest. (* NB Full Moon 24 Nov 14.31hrs).

Piers Corbyn 20 November:
Storm Update Message from Piers Corbyn WeatherAction Tues 20th Nov 2007
PLEASE PASS ON TO ANYONE CONCERNED
Citizens,
The first storm wave is now showing on forecast maps for Friday 23rd/Sat 24th Nov. AS PREDICTED.
The situation is also open for the second storm wave to follow.
We repeat our warnings
1. Standard meteorology will underestimate winds and rain even from 24hours ahead particularly for forecasts of weather in period 24th to 28th Nov.
Our estimation of top gusts over 90mph very likely in the region of the storm track remains, with 100mph likely to be topped in exposed North sea/Island/and perhaps some headland parts.
2. FORECAST USERS should note our projected storm tracks and short range information for estimating top gusts in their area. From 24 hours ahead standard meteorology will probably be reasonable about storm tracks but underestimate wind strength and rain.
The core regions under threat in our long range forecast map for Storm wave 1 remain Scotland, parts of NE England and Central/South Norway and - to a lesser extent - North Denmark.
Forecast Users in Holland and Belgium please note that they were never forecasted to be in the core storm track for storm wave 1 and will not be in it. (Wave 2 is likely to be more important in wind terms for Holland and Belgium). The main threat to Holland and the East/SouthEast coast of England from storm wave 1 (and probably also storm wave 2) will be the North Sea storm surge which will coincide with a series of exceptionally high tides - close to highest possible tides on and after 24th November.

Piers Corbyn 25 November:

URGENT AND IMPORTANT SEVERE WEATHER WARNING
You are welcome to circulate this warning as you may require
Our apologies if for circulation list reasons you receive this document twice

25th/26th Nov 2007
To Emergency Services, Local Authority Risk managers, media and WeatherAction forecast users.
UPDATE on forecast period 23-28th Nov (original central highest risk period for dangerous events) - now extended to 1st/2nd Dec
[This is a 'superstorm' period in English & US usage of the word meaning it is likely to include in the most exposed parts of main storm tracks winds gusting to over 100mph (160kph) - ie resulting from Hurricane (Beaufort Force 12 ) winds]
The period is on the 304th anniversary of the devastating Tempest of 26th/27th (modern calendar) Nov 1703 in which thousands died mainly in Bristol, the South coast of England and London, and Portsmouth was destroyed. Although there are some similarities concerning solar forcing factors of storms developments, events of that magnitude are NOT forecasted for this period.
At the time of writing (25th Nov 22.00hrs), deep low pressures are developing -as forecasted - over the Atlantic and short range standard forecasts show 'dartboard' (exceptionally deep - eg 955mb*) lows. Predicted solar effects make the present period one of rapid and accelerating weather change for the whole of the north Atlantic region from Greenland to St Petersburg and from North Norway to Belgium which will often get ahead of standard meteorology forecasts.
We continue to forecast the British Isles and the North Sea area are likely to be hit (90% confidence) by a major storm(s) and associated substorms including possible tornado type events - particularly in England - starting to show from Weds/Thursday Nov 28th/29th onwards and this or these storm systems to then move into Scandinavia in an now extended period to 1st/2nd December

Piers Corbyn 1 December:

LATEST STORM NEWS UPDATE Sat 1st Dec 20:00hr GMT
The storm now approaching is set to track on Sunday 2nd Dec through England
and into the South of the North Sea and Denmark and bring storms, damaging
winds and exceptionally heavy seas through parts of a wide area including
Ireland, Wales, England (Central, SouthWest, South, SouthEast and East Anglia),
North France (especially Cherbourg Peninsula and Normandy) , Belgium, Netherlands
and Denmark. TRAVEL is best avoided
These events are in line with WeatherAction's long range forecast for the second - 'Southerly
track' storm(s) in the extended time period to 1st/2nd Dec and the original warnings spelt out
in WeatherActions long range forecast first issued 11months ago

For those who don't know the region, the UK generally has a wet and windy period around now. The local name for this phenomenon is "winter". My own patented long-range forecasting methodology(*) enables me to exclusively reveal here, for the first time, my prediction that "winter" will return in November/December next year. With 90% probability, anyway.

(*) Sadly the margin of this blog post is too small to contain the marvellous proof of the skill of my approach.