2005-04-29
EGU: friday
The complete disconnect between the publicly visible debate and the scientific debate is very striking. No one here is saying, will there be GW, only, how much will it be, and I didn't see anyone with a sensitivity below 1.5 oC (and the author of that noted that it was probably low). And even starting with that example is misleading: the vast bulk of the conference is about things invisible to the outside: atmospheric teleconnections (e.g. my poster...), model inprovements, etc etc etc etc. The reason is easy to understand: discussing the technical details is tricky, requires technical knowledge and access to the literature; whereas wurbling about what Richard Lindzen said n years ago requires (perhaps even demands...) very little. And of course the things that the press depts direct into the outside world are biased towards the sexy stuff.
Palaeo session, which should be good. Whaqt would be intesting would be some detailed debate about the discrepancies between the various recons. But we don't get that, sadly.
Medal-winning Goosse: ECBILT model: EMIC, 100 sims, last 2kyr. Ensemble mean v similar to MBH (later shows also sim to Moberg, if you scale Moberg down. Someone Qs this: to which Goosse replies (what the RC post on Moberg pointed out) that most of the Moberg wavelet stuff is non-dimensional; it needs to be scaled at the end, and is, to ?1850-1980?, so there is ambiguity in the scaling)). Now, we assume that the ensemble mean averages out the noise and so represents the response to the forcing. He then points out the obvious: that individual members can differ strongly from the ensemble mean. But the true climate of the earth was like one of these members: so we have to be careful about over-interpreting regional effects in the reconstructions: they may just be natural var. He then selects the member most like a reconstruction (either fit to MBH hemispheric mean, or a European only, or) and then that effectively gives you a sort of model interpolation of the proxies.
Allan: 5x5 degree MSLP reconstructions back to 1850 (www.hadobs.org). He seems to lack Antarctic data... I must mail him.
American/Pacific proxies during the "MCA" (ie, Mediaeval climate anomaly, a term he prefers since calling it the MWP is odd, because the period usually called the MWP was cold and dry over there...). Then deducing some ENSO-type EOF'd tropical pacific SST pattern and using that to force a GCM, but possibly that was stretching things a bit.
Edwards: W N America/Canada: otoh he has a MWP that is +4 oC (from something to do with C13). Whew! But when q'd on this he appears to be unconfident of the scaling, though he insists on the shape.
And then off to the posters, and mine in particular. And thats about it...
2005-04-28
EGU: thursday
But on to the science. Starting with Stephan Rahmsdorf (of RC fame...) presenting The Case for Anthropogenic Climate Change. By which he doesn't mean why it would be a good idea. Mostly, he is reminding us all of the std case, the overall picture which can sometimes get lost in the details. He draws an interesting distinction between the two cases: (a) that there is an anthro signal in 20C climate, and (b) that there will be anthro ch in the future. And points out that only (b) is policy-relevant, and that a and b are logically distinct. Which are both quasi-true, but of course they are linked: the same models that reproduce 20C are used to run forwards; and if you are the sort of person who can't cope with the 20C results you are liable to reject the future ones too. Finishing with what is the climate sensitivity? The 1.5-4.5 oC value has been around for a while now, and he suggests more convergence at around 3 oC. And certainly (see below) the UK and French AR4 trends end up similar to the TAR trends.
Dansgaard-Oerscher events session: dip into this for a few talks just long enough to discover once again that I don't get much from them. D-O events exist (during the last ice age), they have global implications (they can be seen in, say, Indian ocean proxies). But apart from that, what? They are either quasi-1500 year periodic, as a result of internal osc of a non-linear system; or they are exactly 1490y periodic (with a few missing; Rahmsdorf, recently) which implies an unknown external forcing. And then Bond now says that his haemetite-stained-grains as a proxy for arctic ice advance-retreat says a 500 y cycle fitting into the D-O cycle. Errrm.
A trilogy of talks about IPCC AR4 simulations from 3 european models. Firstly (of course...) HadGEM1. Probably the key end result is that the transient global temperature trends are about the same as for hadcm3. In more detail: hadgem is now n96 (ie, twice cm3 atmos res, etc etc: see the tech note for details). Gem has mostly lower land-sea trend contrasts, ie the land warms less and ocean more than cm3, except, Antarctica warms more, though the diffs aren't large. The ocean heat uptake is sim to cm3, perhaps a bit more. Storm track changes (to CO2 doubling) small. Rather more interesting to me are the P-E changes over Antarctica and Greenland, which are rather different to CM3. Ant P-E increases by a factor of 3 more: due to inc T there and higher P there to start with, apparently. Which bears investigating: since the Ant ppn was a small lowering of sea level in cm3, it might now be a rather larger one. Over Gr, the reverse: there is less melting in GEM. As for the THC changes, GAM starts with a lower THC than CM3, but the drops are about the same, so the GAM % drop is larger... The number of IPCC scenarios run seems to be growing: a1, b2, a1b, etc.
Salas-Melia, on the CNRM-CM3 model (nb their CM3 isn't anything to do with hadcm3). And again, the AR4 trends are pretty similar to the TAR, with various details.
Hagemann: the MPI model, completing the trilogy of european coupled models. He mostly talks about the hydrology, which appears rather messy to me - river catchments and stuff. The coupled simulations show improvements over the AMIP (ie forced SST) runs. This is in some senses wrong, in that it means there is probably some cancelling of competing errors in the improvement, but he also asserts some improvements via the coupling process. Hmm.
A Danish sim of 1500-2000. Not sure exactly which model (probably echam/opyc, but run with Danish forcing). End result is lower var that von S - fits between Moberg and MBM.
NARCCAP (www.narccap.eucar.edu) talk: but I'm not interested in regional models... Phase I involves 50km res regional models run from NCEP/ERA boundary conditions. But why bother, since ERA res is just about 50km anyway (isn't it?; it can't be far off).
Last of the morning: is cl ch res dep? Looking at ECHAM4 (t106) then REMO
regional model (for eastern Europe) at 0.5 degree and 0.16 degree. Forced, I think, by SST changes from a transient run (with the REMOs run from ECHAM4 atmos boundary conditions, I assume). And the end result is... no, it doesn't make a great difference. But of course the regional model only has limited freedom, as it should be.
Boring first after-lunch talk (I won't embarass myself or the speaker by saying who; while away the time by finding that there were more than 25 talks I could be attending at 13:30, not to mention the poster sessions) redeemed by an excellent poster session with a number of interesting ideas, notably from James Annan. He has several posters... one on a futures market for climate change, trying to explain to the climate folk how these markets work, the value of y/n coupons and stuff. Which I confess I find rather hard, probably just the unfamiliarity. It is said that weather futures markets demonstrate useful weather-type predictability up to a month ahead: www.cme.com/files/EPSept03.pdf. More mainstream is his (why do I keep saying his? They are joint with Julia Hargreaves) on ensemble Kalman filters for doing things more efficiently than climateprediction.net (or Qump). He convinces me though I'm still a little unclear what an eKf actually is, in some sense it constructs the probability distribution function for a perturbed-physics ensemble. Then you weight the sensitivities for 2*CO2 by how well they match the LGM (of about 5-7 oC). And you get 4 oC +/- 0.6 oC, plus or minus some problems with the ancil files.
Someone on the probs of exceeding 2 oC T change... which has recently been re-affirmed by the EU heads of state as a target level. So, with 550 ppm you get a pretty good chance of exceeding it, and you have to drop down to 400 ish to be reasonably sure of not doing so. So we will exceed it.
Mori on ICA which is better than PCA/EOF apparently.
Various THC talks, not really my thing.
Coffee with Gavin.
Climate sensitivity. James A again! A rather good (as far as I can tell) talk but the details are complex: he really needed an hour not 15 mins, at least if he wanted to make me understand it all. So... using the forced Lorenz model as an example (Palmer), and a deliberately imperfect model (ie, by making one of the parameters wrong) he then fits, using the std techniques, an ensemble of models to the "obs". And the point is not to get the right results (its "climate sensitivity": you get the wrong answer, and you know you will) but to get a result where your estimate of the PDF of the climate sens includes the true value within what you consider to be the 95% range. And he demonstrates that the std estimate doesn't do this: the true value is 25 stdevs away. But... aha, using magic (including the model error in the metric) you still get the same wrong asnwer *but* you end up with the true value within range. Then, comments on the Murphy et al Qump results, pointing out what appears to be an arithmetic error of theirs, which effectively scales their results, and I think the point is that this scaling makes their results fit, whereas if they hadn't they wouldn't. An anonymous questionner asks if simply scaling the J matrix (cost function) makes no difference but this seems to be not true, or at least JA maintains it so.
Section 889, Ney York state code of criminal procedure, section 901: persons claiming to predict the future should be considered disorderly...
Frame: CP.net stuff. Not what I wanted to hear (which was, what happens when you exclude the implausible results based on tighter criteria) but misc: fixing the entrainment doesn change the spread of climate sensitivity. Fixing the cloud scheme does: with just the std scheme, the max goes down to about 6 (from 12 oC).
Enough. I'll just about survive tomorrow I think.
2005-04-27
EGU: wednesday
Talk 2 is Beer on the forcings, with lots about solar. He says that most of the irradiance reconstructions are scaled to a Maunder Minimum value. He doesn't believe (and gives the impression that this is generally so) Lean's value of ?0.24%? based on sun like stars, which leaves the question of what the value actually is "open".
Cubasch then does the modelling aspect, mostly over the last 1000 years, which is mostly the von S Science paper. The forcing (it emerges in questions after) is probably the Lean '94 (not '01) that people now think is too big. They combine (for quickness) solar+volcanic into a modified solar input, which then looks like small variations and big downward spikes for the volcanoes. This presumably misses interesting interhemispheric diffs you would get if the volcanic went in more realistically via aerosols. He compares his results to Mann and to Moberg (ignoring all the others) and finds, of course, a better fit to Moberg; but is careful to leave open the question of which is correct. He also claims a natural Hadley run supports his model - must take a look at that (apparently its in the supplementary material for the von S Science paper).
Tarasov does some archaeology for a site in China. A bit detailed, in itself, but this is to illustrate (1) the value of interdisciplinary talking and (2) to point out the way that people from different disciplines view one anothers data... modellers tend to believe the obs, whereas to obs people know enough of their faults; historians use "MWP" myths to support his studies which the climate people take up to classify their results which the hist people use to... and it can be somewhat circular.
Vinther: an innovative attempt to deduce temperature profiles from the GISP site. The idea being that the diffusion of the O18 signal in the firn is T dependent, in the upper cores, so for suitable cores, with enough but not too much accumulation you can potentially invert the reduction-in-seasonal-o18 signal to deduce T. This applies for 4kyr at GISP. And the result is... about 3K drop over that period. Which is more that the raw d-O-18 gives you, and more than inversion-of-borehole-thermo gives you, at GISP. So it was clear that there was opposition to this new idea, presumably people will check it out. Qs were, how do you know there wasn't a ch in the input seasonality cycle (eg from Milank; sez Beer) over that period? Ans was that at Dye-3 (where acc is higher, so diffusion doesn't smear the seasonal cycle) there is no corresponding ch in amplitude.
And lastly some sea ice. Results from IPCC AR4 runs from Salas-Melia; and some sea glider obs of, err, a piece of sea which all the oceanographers knew by name but I didn't; poss the Labrador sea; between Greenland and Canada. Sea gliders are fun: they are about 2m long, and they glide. So they are better than buoys (you can direct then, pre-programmed, on various trajectories) and better than powered AUVs (because they use little power they can stay out for 6 months).
And now I'm bunking off for a nuice sunny afternoon of Vienna-viewing.
2005-04-26
EGU: tuesday
EPICA session: starts off with Berger: origin of 100kyr cycle: maths. As he says, the full sets of periodicities for the various elements of ecccentricity, obliquity, etc are rather complex, and he reports on often getting annoyed by the over simplifications some papers present. Nice pictures of wavelet analysis of the various components, showing how the eccentricity has been shifting from 100kyr in the past towards 400kyr in the future (yet another reason not to take the future predictions of an immenent ice age seriously: again, the future is not necessarily like the past).
Quick run round and downstairs to: global dimming or brightening? (Lohmann) From ISCCP rather than ground (not quite clear how this is done); since 1983; more brightening than dimming; BUT clear artefacts in the data showing the edges of the satellite field-of-view. So the results are hard to interpret. But brightening is consistent with Wild since the start of the 90's. If you can trust the satellite data, then Australia is an island of mild dimming in an ocean of brightening; so the few ground measurements may not be typical. If (again) you believe the satellite data then the trends are due to cloud trends (which I suppose is obvious, given that this all starts from ISCCP data). OTOH that was all for direct radiation; the total (inc diffuse?) shows far smaller variations (which would explain the lack of climate effect).
Eric Wolff: very interesting talk (as representative of the EPICA chemistry team) about chemistry from ice cores (disclaimer: he is a colleague of mine). He had a few controversial things to say. That MSA glacial/interglacial changes (at least at low-accumulation sites) is dominated by post-depositional effects. So that the "conventional" interpretation of MSA is completely wrong. Proceeding, he convinces us that the Sodium (non-sea-salt fraction?) is a proxy for sea ice (frost flowers), and then shows that there is a near-linear relationship between sea ice extent and temperature over the last 800kyr (with no break at the 440kyr point, where the cycles change their nature: the interglacials before then are cooler and longer, so the overall cycle is smaller). Using the sulphate (not the MSA) signal, he finds it near constant (in complete constrast to MSA), hence that marine biogenic production was near constant, which may have some implications for CO2 drawndown and stuff.
Ganopolski: CLIMBER model. How well it does for the past; spectrum matches SPECMAP well for past 800kyr. But it doesn't fit the volume before 400kyr, because it assumes compete deglaciation, which didn't happen before the last 4 cycles. So he stuffs in a 15% floor before 400kyr and gets a better match. This model predicts a 50kyr long "natural" holocene (so MIS 11 400 kyr ago, which was 23kyr long, is not a good natural analogue for now; instead, he predicts that the "natural" now would be an analogue for the stage about 400kyr in the future). But as he notes, anthro CO2 will impact this. Using Archer (2005) CO2, of 5000 Gt CO2 (C?) emitted now, which lasts for a *long* time (goes up to 1000 ppm; doesn't recover below 400 ppm out for 400kyr), which wipes out the glacial cycles for the next 400kyr. Mysak has much the same results.
Coffee break: no coffee :-( no water :-(((. Is this really Vienna?
More EPICA. Zeng looks at carbon fluxes, and what happened to the high latitude forests during the last ice age. the conventional picture (apparently) is that this veg gets swept away during an ice age and the carbon ends up in the atmos, which means that the ocean needs to draw down even more, since CO2 does down during ice ages. He proposes, instead, that it gets buried under the ice. This is an interesting question, though for all I know well discussed already. Would there be remains to see? Perhaps.
Siegenthaler gets to show the long-awaited EPICA CO2 record. The O18 record has been around for a whie (published in Nature) but CO2 takes longer: pics of the "cracker" (which crushes the ice: reproducibility 2.5 ppm) and the "sublimator" which is more efficient but slower: 2 samples/day. It is important not to let the ice get wet in the process. So: the "EPICA challenge" was to predict the CO2, given the O18 (and anything else you liked). The O18 shows lower cycles before 440kyr; it turns out that the CO2 pretty well follows the O18: smaller amplitude cycles and lower interglacial values. But they don't say who won the challenge :-). The CO2-ice age offset varies from 2-6 kyr (I presume by modelling / acc rate) and the CO2 lag to T is 1-2kyr, ish, based on matching some key events, though with one +ve lag.
Lunch: giving up on the Qs go to the ubahn and a nice backerei; then walk down by the river. The conference centre is in a block of huge glass-steel-concrete buildings on the far side of the Neu Danube from the main city. The biggest (and to my tastes the best) is "UNO city". The conf center is probably the ugliest, a squat concrete object with a generic resemblace to the Acropolis (in Nice, *not* the one in Athens...). There is an interesting "cube" building which has a projecting glass cube near the top that gives the illusion of floating in front of the building. However, the entire grouping lacks human scale: you walk vast windy inhuman alleys between monsters. Though at least the grouping of the buildings allows for nice parks all around.
After lunch: more misc things; the EPICA Dronning Maud Land core (EDML) matched to Dome C (EDML is not on a dome hence the ice flow modelling is harder (indeed they seem to be aging it by matching to EDC) and the core shorter (in time)). But, it gets influences from a different sea and the comparison is therefore interesting, allowing people to deduce that dust transport doesn't change much but sources (Patagonia) do. Interesting factoid: the 41kyr obliquity signal is missing in EDC before 440kyr.
Poster time: standing in front of the Hadley+me Hadgem-sea-ice poster. Time to look round first: misc: Kaspar and Cubasch: 115 and 125 kyr sims with ECHO-G run for 3000 years! Finding that insol variations *are* enough to explain the T response and to show a long term cooling at 115 kyr: this explained by feedbacks from growing snow cover. This is more like it...
Talking with TJ re the "1860 control" question. HadGEM (and CM3, and indeed most/all coupled GCMs) are spun up to "pre industrial" conditions nominally 1860. Most of the reason for this is that you want to start your transient runs from then to avoid a cold sart problem. But, it means you control run is not really for modern conditions but a colder world. Which affects, eg, your validation of the sea ice. By an unknown amount.
GRACE: continental water storage and the 2003 drought. If you look at the estimsates of sea level rise and the various contributions, continental water storage is one of the major uncertainties. Apparently you can use the GRACE gravitational measurements to look at the year to year variations of water storage, which is interesting. Something like 8 cm (locally) for the 2003 drought.
Eric Steig: siple/byrd/taylor dome ice cores and cross comparisons to GISP. Looking at the coherence and phase at various frequencies shows good coherence up to about 1-2 kyr periods, and then little past then. Which he interprets to mean that the timescales are not synchronised to better than that. There is a 20kyr Rapid Warming in the siple core not seen elsewhere. There is a "feature" at 15kyr in the taylor core which he is coming round to interpreting as a snow hiatus (either, no snowfall or it gets scoured off, resulting in the loss of an unknown length of the core. Which could mean re-interpreting some of its matches to the other cores. All of this is "only" the last 100kyr)
2005-04-25
EGU: monday
Today: talking to B on the way in about Why Vienna, since although its a nice city its rather less convenient than Nice. The answer is that Nice (acropolis) was, err, abusing its commanding position to lean on EGU; so we had to show independence. And EGU has grown from 2k to 8k over the past 10 years so other venues, eg Grenoble, no longer work.
Anyway: the science.
First, to the Cryosphere for Hans Oerlemans work on temperature reconstructions from glacier lengths back to 1700. This was RC'd a little while ago. The talk pulled out some stuff that wasn't in the RC post, and perhaps not in the Science paper: that the changes are quite synchronous globally (the available glaciers are widely but sparsely distributed: but if you remove the alps, where most are, the picture doesn't change much). And that this isn't the sort of thing that the glacios are used to doing. And that most of Oerlemans records stop in mid-1980's and he would like to get them up to date.
A bit more cryo from Alaska: more lowering glaciers.
Then solar stuff: a bit outside my field. Usoskin (...and Solanki) on T-solar corrs back to 200 AD, using CR (cosmic rays) and SN (sunspot #) reconstructed from isotopes. Some split into, I think, short-term var (ie 50-y odd) and long term trends. CR fits better than SN. No good corrs for short-term; better for trends. Which brings up the question, why doesn't it corr to the short term? Do they expect a very delayed response? Which brings up the next talk...
Gleisner/Thejll: looking at solar/t corrs in the reanalyses. Oddly, ERA and NCEP are quite different: good corrs in NCEP, poor/none in ERA. I would have said ERA was better, but then I'm european. He does some multi-var regression to extract solar/enso/volcanic signals, leaving residuals. In ERA, the residuals look like noise: in NCEP, there is clearly a pattern left. He didn't mention that... But he did look at the match to the RS dataset: which was interesting: looking at the fit over the RS and non-RS areas shows patterns that on first insepction look bad for ERA, though imperfect for NCEP too. So I ask, "you expect an instantaneous response?" and clearly they do, since they are correlating unlagged T and Solar. But this is the opposite of what the prev speaker did, though on rather different timescales. And its fairly clear that they haven't really thought about this. The answer I get is "but these are very different timescales" but I don't find this fully convincing: the 50-y average of a good correlation should still be good. They are at the correlating things stage, which is a long way beyond the modelling/mechanisms used for GW type stuff.
After that, brief attempt to make wireless work: fail: the DHCP is broken, apparently.
Coffee time: there is no coffee, unless you get there early or Q long. This is tradiational. To my/our poster (hadgem sea ice vs hadcm3 vs obs), with AJ, and find a Met O chap reading it (JKn, I think), and we have a good talk about the poster, and hadgem. Bill Hibler has the poster next door but its technical. Other misc posters, finally meet Joy S.
After this misc; get wireless working (the man in the magic brown jacket knows the answer, which is 10.59.1.x. Aha! Meet up with NvL, now in Munich; and James Annan, who has a mail from RL saying that the quote at the bottom of http://www.reason.com/rb/rb111004.shtml - viz, Richard Lindzen says he's willing to take bets that global average temperatures in 20 years will in fact be lower than they are now is actualy a misquote, and he won't make any such bet. So JA is trying to pin him down. Doubtless RL will be writing to Reason to correct this misquotation which might potentially be considered a bit misleading.
Lunch: again, Q's of stupendous vastness, fortunately I have half a roll I didn't finish at breakfast :-). Again somewhat worse than Nice, where the cafes began just outside the venue; here the conf is out in "UNO city" about 10 mins U1/metro from the center.
[Update: pm]
Try to see a solicited talk about N Pacific T from argos floats; but cancelled. Only realise this when I start hearing something different (and less interesting). Still, the wireless now seems to work in the lecture halls. Skip out in the hope of coffee (missing Lherminier and Mertens, sadly (thats a mustelid joke folks).
After to the polar session, and about time too. It is mostly Arctic, which is dull, since we all know the Antarctic is far more interesting. Goosse gives a talk about NAO, modelling, etc; trying to select the best run (from more than 100 of the last 150 years), the idea then being to use the best run to help diagnose what has happened. This might be an interesting idea but isn't worked out in detail yet.
After yet another coffee break without coffee (it seems that the only way to get a short Q is to take your coffee breaks during the sessions), back to Polar. Peter Wadhams is still doing the ice-thickness-from-wave-propagation stuff, but no actual results yet. Dethloff on "global impacts from the arctic" but this turns out to be mostly changing the albedo parametrisation and discovering the effects on h500, which don't seem to be huge, though predicatably enough there are blobs scattered around, somewhat on an NAO/AO-ish style.
Elizabeth Hunke (so thats her! I've written a paper with her, and now see her talk,
and then go up and say hello afterwards): some interesting differences in the
kinetic energy of ocean models runs with Gent-McWilliams vs Biharmonic diffusion. GM is cleverer (hadcm3 and hadgem use it, it does lots of good things), but appears to be lacking in the Arctic, and this turns out to be because of some scale-selectivity of the diffusion which over-smooths in the smaller grid boxes (only when you get rather close to the poles, past 70 ish). The obs being sparse its not too easy to say which is correct, but runs "correcting" the over-smoothing looked good.
Then arctic sea ice (var and declines; interesting freshening of deeper waters) and water masses and stuff: quote "ACIA may be over-optimistic" in that the changes could be faster than that... still, with natural variability, its hard to be sure.
And thats it for the day. The wireless magic IP numbers have changed, but DHCP is still not working. I get some new magic numbers, and somehow accidentally type in an incompatible gateway/ip combination: nonetheless it works. How odd. Cafe time...
2005-04-22
I dwindle, go unnoticed now
Osip Mandelstam was a poet in Russia, but his later poetry didn't please Stalin, and he spent his later years in exile, serving sentences for counter-revolutionary activities in various work camps, until his death on December 27, 1938, in the Gulag Archipelago. I only know of him because of the fragment that starts "The Sword of the Lictor" by Gene Wolfe:
Into the distance disappear the mounds of human heads.
I dwindle - go unnoticed now.
But in affectionate books, in childrens' games,
I will rise from the dead to say: the sun!
Now I look for the source, I find that the "official" translation is:
Mounds of human heads are wandering into the distance.
I dwindle among them. Nobody sees me. But in books
much loved, and in children's games I shall rise
from the dead to say the sun is shining.
I prefer the Wolfe version (is it his own version? I don't know). I would also omit "from the dead" from the last line, and perhaps change rise to arise, if I was writing my own book. Since Osip Mandelstam is a bit of an odd name, and the poem distinctly odd, I had wondered if it was an invented quote, with no convenient way to find out. But now google will tell me in seconds.
For completeness:
Book 1 starts with A thousand ages in thy sight/Are like an evening gone./Short as the watch that ends the night/Before the rising sun - which is a hymn based on Psalms 90.
Book 2 with But strength still goes out from your thorns,/and from your abysses the sound of music. / Your shadows lie on my heart like roses / and your nights are like strong wine, which appears to be a GW original and I think you can tell [*].
Book 4 is AT two o'clock in the morning, if you open your window and listen, / You will hear the feet of the Wind that is going to call the sun. / And the trees in the shadow rustle and the trees in the moonlight glisten, / And though it is deep, dark night, you feel that the night is done, which is Kipling.
TUotNS (which I found rather disappointing) is "Awake, for morning in the bowl of night..." by Fitzgerald; my father used to quote that a lot.
[*] Ha, I'm wrong. But I'm correct that its weird. Its actually Gertrud von Le Fort; see for example google books. "Thorns" is then the obvious Christ reference; but "Your shadows lie on my heart like roses" is beautiful. Thanks to JY.
2005-04-20
Royal Soc: A guide to facts and fictions about climate change
2005-04-19
New Scientist woes
Why does NS print these things? Ignorance? Stupidity? Or just a mischievous attempt to stir up controversy and try to sell more magazines? Probably the latter.
2005-04-18
2005-04-15
We can’t predict the weather a week in advance. How can we do it 100 years in advance?
To get you in the right frame of mind, consider an analogy: sea level at the beach. You can't predict the height of the next wave, or even when a wave will strike ten minutes from now. Yet the tide can be easily predicted years (centuries, probably millenia) ahead.
A better analogy is with throwing a (fair) die: you can't predict whether the next throw will be 1, 2, 3, 4, 5 or 6; yet you can be fairly sure that if you throw it 1000 times you'll get very bored. Sorry: If you throw it 1000 times, the average throw will be close to 3.5. And to pursue this a bit more, if you make the die a bit unfair (by, say, making the 6 twice as likely to come up) then you still can't predict what the next throw will be. But you can be sure that the long-term average will go up to... thinks... about 4 1/3.
Weather is, we are fairly sure, intrinsically unpredictable past a certain limit that isn't precisely known, but is about 1 month. In practice, current NWP (limited by computer size, model completeness and starting obs) can be useful out to about 2 weeks at a stretch. The weather is thus chaotic. As far as can be seen, climate isn't. Obviously, some features of climate can be predicted far further out: we know that winter will be warmer than summer, for a trivial example. But what about the trends in global mean temperature over 100 years? In this situation we have an imposed forcing (increasing GHG concentrations) on top of a chaotic system (weather) which appears to average to a non-chaotic system with intrinsic predicatability (climate).
If you trust the models, you can test this: if you start an atmosphere-only model with differences in the starting state differing only at the numerical-accuracy level (which is far below the obs error the NWP starts from) they diverge within a month. But if you then take the long-term mean of the runs, they are the same. If you start coupled models off with small differences and GHG forcing, they again differ on the weather, and the year-to-year variations in the global mean; but the long term trends match.
2005-04-12
Oh Larsen B
Is this the first ever song written for an ice shelf? I suspect so.
The lyrics are:
You're fractured and cold, but your heart is unbroken
My favourite, foremost coastal Antarctic shelf
Oh Larsen B, oh you can fall on me!
Oh Larsen B, desalinate the Barents Sea!
Oh I, I think it's over again
Like sawblades through the air, your winter overture
Cut through everything, and now we're not so sure
Oh Larsen B, oh won't you fall on me!
You had 12,000 years, and now it's all over
500 billion tonnes of the purest packice and snow
Oh Larsen B, oh won't you fall on me!
Oh Larsen B, desalinate the Barents Sea!
Oh I think it's the start of the end
Like sawblades through the air, your winter overture
Cut through everything, and now we're not so sure
Oh Larsen B, oh fall on me!
Oh Larsen B, oh fall on me!
Oh Larsen B, won't you fall on me!
Oh Larsen B, Oh Larsen B
Oh won't you fall on me!
Oh you can fall on me!
Quite why they pick the Barents sea when there is a perfectly good Weddell Sea to use instead I don't know. Ditto the 12kyr. And it wasn't packice. Isn't pedantry wonderful.
2005-04-10
UK govt record on climate change
The general tone of this assessment, in case you want to skip the details, is that the rhetoric has been good but the action disappointing.
I don't dismiss the value of the rhetoric, though. Compare it to the Bush presidency, which has done its best to downplay climate change: Blair has said some strong things, like "What is now plain is that the emission of greenhouse gases, associated with industrialisation and strong economic growth from a world population that has increased sixfold in 200 years, is causing global warming at a rate that began as significant, has become alarming and is simply unsustainable in the long-term. And by long-term I do not mean centuries ahead. I mean within the lifetime of my children certainly; and possibly within my own. And by unsustainable, I do not mean a phenomenon causing problems of adjustment. I mean a challenge so far-reaching in its impact and irreversible in its destructive power, that it alters radically human existence." (#10). Well: you can't get much plainer than that, and Brown says much the same. Greenpeace could ask nothing better, from a speech. In fact (from my own WGI perspective) he has gone rather further than he might (see here too). Whereas Bush has never acknowledged that humans are causing climate change.
So: rhetoric OK, what about action? If you were faced with a challenge so far-reaching in its impact and irreversible in its destructive power, that it alters radically human existence you'd be doing some pretty serious things, yes? Well, no. "The UK government is not doing enough to tackle climate change, according to a report by a parliamentary committee. The Environmental Audit Committee attacked ministers for believing that new technology and market mechanisms will reduce greenhouse gas emissions." (from the BBC; thanks HET). And the reason why is not hard to see, when reports say stuff like: "Eighty-thousand houses need to be demolished yearly for the next decade if the UK is to meet its climate change commitments, research suggests. Such demolition of older houses built to low environmental standards would be four times the current rate, Oxford University researchers said. It would mean the replacement of about 14% of homes, with 220,000 new homes built and others improved. ". (BBC again). The govts isn't going to be keen on spending money on that, when money is tight anyway (arguably they have done a fair job demolishing old houses in Iraq, but that doesn't help). Its a commonplace to note that the only reason the UK is at its current emission levels is that the Thatcher govt encouraged/permitted replacing coal fired power stations with gas. Labour has done nothing comparable; and its given way to the car-driving lobby over fuel prices.
Looking at the Blair speech again, lower down (after a review of some modest things) he says:
I want today to highlight three key parts of my G8 strategy.
First, I want to secure an agreement as to the basic science on climate change and the threat it poses. Such an agreement would be new and provide the foundation for further action.
Second, agreement on a process to speed up the science, technology, and other measures necessary to meet the threat.
Third, while the eight G8 countries account for around 50% of global greenhouse gas emissions, it is vital that we also engage with other countries with growing energy needs - like China and India; both on how they can meet those needs sustainably and adapt to the adverse impacts we are already locked into..
This isn't impressive. Point 1 is perhaps a nice idea, not sure exactly what it means, probably it means "get the b*st*rd Bush to agree on what everyone else knows" (at least as far as the basic science goes; well we have IPCC, what more do you want?; perhaps the "and the threat it poses" is the point at issue). Point 2 is vague-to-useless. Point 3 looks like a sop to the Bush-y view that developing countries need to sign up too. Nice idea, but with rich folk like us (we are rich, aren't we? People tell us so, but nowadays it seems that both parents in a family need to work whereas in the good old days only one half did...) not doing much, why should the developing folk do more?
And at the end of it all, the reason that there is less action that the rhetoric suggests, and why for example Blair is supporting a new runway at Standsted with little regard to the extra CO2 it will generate, is that while people will generally nod to the dangers of climate change, they don't want action to get in the way of their cheap flights or their driving or... So anyway, its not all Blairs fault: he will, quite often, do what the voters want (the Iraq war being an obvious exception).
2005-04-09
"Honest broker"?
All this starts with RPs "Scientizers. This large and diverse group actively works to frame the climate issue as a scientific debate under the expectation that if you win the scientific debate then your political agenda will necessarily follow. This group is comprised mostly of scientists of one sort or another. I would include here the dueling science-cum-politics weblogs Realclimate.org and Climateaudit.org (we had an exchange with Reaclimate folks a while back). I would also include here CATO's Patrick Michaels..."
Naturally enough, various RC folks including me objected to being lumped in with the objectionable Michaels, not least because of comments RP himself has made about Michaels. And I object to the assertion that we're doing this because "...political agenda will necessarily follow". RP seems to have a real problem believing that things can be done for good science not for political reasons.
However, my real problems with RP are his response post, on 8th April. Much of this is to do with language, words and nuances. I think RP is spinning things. From my point of view, the language he uses is slippery, not straightforward, designed to lead you into his viewpoint rather than argue you into it. I find this hard to put into words.
1. RP starts with "Firstly, there is the honest broker who seeks to expand (or at least clarify) the scope of choice". At this point, all is fine: "honest broker" is a nice phrase, sounds good, not quite sure what it means and doesn't seem to fit the scientific context, but never mind. If you're making a choice - like, how should we consider our future CO2 emissions policy - then the scope of that choice can clearly be clarified by, say, better predictions. Ie, by science. But then, RP defends himself with I equate "scope of choice" with "openly discuss policy options". Which I find bizarre. Its just a complete disconnect. Words mean what I say they mean, humpty-dumpty stuff.
2. RP says I "wonders why I [RP] differentiate between RealClimate and Journal of Climate". No, of course I don't wonder that, because to differentiate us is easy. What I said was "Finally, your saying "there is plenty of discussion of climate science with no extra-scientific context. Just look at the Journal of Climate..." is misleading - you are using that to imply that RC isn't in that state, without ever presenting any arguments for why." (refer back to Gavins comment and further). I'm saying, RC is science - which it is - with no policy (or as little as we can manage). RP has created a strawman to avoid answering the point: which is contained in his response to Gavin: "You appear to be under the impression that no discussion of climate science can take place without having an explicit or implicit policy agenda." Of course I believe that there is plenty of discussion of climate science with no extra-scientific context - RP has now twisted this to try to exclude RC from the pure-science arena.
3. RPs My interpretation of the RealClimate blog is that prevailing opinion there is that the political debate on climate centers on science. Where on earth does he get this from? RC doesn't have a lot (anything?) to say on what the political debate centers on. Were you to ask me (about the US pol debate) I'd say that it has a distressing tendency to ignore the science (RPs post trying to paint Prez Bush as accepting the scientific consensus is more sleigh-of-hand).
4. His point 3 - the wide scope of the category he has stuffed RC into - just seems to be some kind of laziness. Or perhaps, RC is unique, and it really is the only climate-science blog out there.
5. RPs response to Stephan (number 2 in his list) is a travesty, and the quote from a previous post "[RealClimate] claims to be "restricted to scientific topics and will not get involved in any political or economic implications of the science." This is a noble but futile ambition. The site's focus has been exclusively on attacking those who invoke science as the basis for their opposition to action on climate change shows this for me. RC has concentrated on presenting the science; and where we've been attacking people or positions we've been attacking the most obvious abuses of climate science. As it happens (and RP has nothing to say to this) the most obvious abuses of the science are coming from the septic/denialist side - which is unsurprising, because the weight of science is against them.
6. Response to Eric. Another travesty. If the folks at RealClimate think that the political debate about climate is in fact not about science then I'd be happy to be corrected. This completely misses the point: whether or not the political debate involves science doesn't affect whether the scientific debate involves politics. We're doing our best to stick to the science, to provide people - ordinary folk and policymakers too - with good information about the science. Who does what in terms of policy is not up to us. RP is obsessed with policy, presumably because its his bread and butter, but there is no need to drag everyone else into it.
2005-04-05
Betting on climate
2005-04-04
Burning my past
The obvious motto, of course, is don't accumulate junk. But its soooooo tempting. Most of the broken-but-fixable things I binned have a history and I can remember it; I find it hard to sever ties with the past. The pencil box I made in woodwork at school, that lost its lid years ago. Gone. A tin of screws and nuts and stuff I inherited from my grandfather. Gone.
I got more ruthless as I went along, of course: being time-limited is the only way, or I would still be agonising over things. But will I learn this lesson and start applying it to the piles of stuff still in the house...?
2005-04-02
Global warming is not from waste heat
From this, global energy use in 1990 was 13.2 TW. It'll be a bit bigger now I suppose. So what is a terawatt? Its a billion kilowatts, err, so that makes it 1e12 watts. All of that ends up as waste heat somehow. I think the area of the earth is 4*1.3e14 m2. So the average global forcing is... 13.2e12/(4*1.3e14) = 0.025 W/m2. Compared to which, the well mixed GHG's are about 2 W/m2 TAR spm fig 3. So waste heat is about 1/80th of the GHG forcing. Which is clearly small globally, and probably so locally too.
[Note: this calculation is wrong, at least in the long term. See here.]