2005-02-28

Global cooling, again.

I wrote about the Global cooling myth on RealClimate a while ago; and there is a more complete but less organised set of stuff at http://www.wmconnolley.org.uk/sci/iceage/. I had hoped that the RC peice would throw up some interesting new references; but only one appeared:

From Physical Geology by Eugene Mitacek, 1971:

WILL THE ICE AGES RETURN? Climatologists report that the world's weather is turning sharply cooler. Signs of this are evident. Drifting icefields have hindered access to Iceland's ports for the first time in this century. Since 1950 the growing season in England has been shortened by two weeks. Director Reid Bryson of the Institute for Environmental Studies at the University of Wisconsin reports that, if this trend continues, it will affect the whole human populace.

A long term study of climactic conditions would place the first half of the twentieth century into an exceptionally warm period. The warming trend peaked in 1945, and the temperatures have been dropping since. The drop to date is on 1.5 degrees C, far from the 10 degrees C drop necessary for a new Ice Age. If this trend is not reversed, however, the planet may be caught in an ice-forming cycle similar to that of the Pleistocene.

That quote is probably copied from http://www.kuro5hin.org/story/2001/3/2/03449/27856. Note that the drop-to-date of 1.5 oC is wrong (by todays climatology, and probably by what they had then). The global cooling from peak (1940's) to trough (1970's) is barely 0.2 oC (see the SPM) and the northern hemisphere only somewhat larger (about 0.3 oC: see fig 2.7). If you took peak-to-trough for individual years (which you shouldn't, because only slightly different years would then get you a warming) you might get 0.6 oC. But not 1.5 oC. However, thats from modern records: what was available at the time might be wilder.

The reference turns out to be wrong (initially I suspected it might simply be invented, but no). The real ref is Physical Geology, Principles, Processes, and Problems by Charles J. Cazeau, Robert D, Hatcher, Jr.; and Francis T. Siemankowski, 1976 (not 1971; thats a relief because 1971 would be an implausible date for a quote of this sort). The confusion arises because the endpapers are a geological chart by Mitacek, which *is* copyright 1971. With the ref sorted out (thanks JM) I got a copy from abebooks, which arrived today (the wonders of the internet; once apon a time getting hold of a copy would have been too tedious to bother with).

However although the ref needed correction the quote, somewhat to my surprise, is in context (you wouldn't believe the out-of-context quoting that goes on elsewhere). The book continues (thanks JM):

Long range weather forecaster Edward M. Brooks believes that the present cooling trend follows a 40-year cyclic pattern. He feels that this trend will continue until 1985. We will not need to wait much longer to see if the trend will reverse. Both Bryson and Brooks are in agreement, however, that the world is heading into a period of weather unfavorable for agriculture. This is extremely bad news because of the explosion of population in many countries of the world. It appears as if we will be producing less, rather than more, food. As food reserves dwindle we may move into a period of massive, unimaginable tragedy. Long-range plans to feed as ever-growing population must be made.

In the last paragraph of the chapter it also says the following:

It is difficult to forecast the outcome of the present cooling trend. Climatologists differ regarding whether a new Ice Age lies ahead. There is agreement, however, in predictions of shorter growing seasons and lower crop yields for the next 10 years.

Now, what do I say to this? Bad news for the good guys? Well no (surprised?). I think it accurately reports Brysons views, but not the general views of the time. The views of the time were "we don't have good enough theory and measurements to predict the future (100 years) climate, and we know it" (see, e.g., the conclusions of the NAS report, 1975). This is a textbook, not the primary literature. So how do we explain the presence of this stuff in a textbook? Its only a tiny fraction (less than one page out of more than 500) and its a geology book not a climatology book. Textbooks are (I presume) not peer-reviewed in the way papers are; and even if it was reviewed it would have been sent to geologists, since its a geology book. People often make mistakes when they go out of their field...

On the authors:

Charles J. Cazeau (1931-1999) was a prof of geology at the State University of New York at Buffalo: this is the major google hit :-); he also seems to have been marginally invovled in debunking "nessie".

Robert D. Hatcher is rather easier to find: he is currently Tectonics and Structural Geology UT Distinguished Scientist and Professor of Geology Department of Geological Sciences University of Tennessee.

Francis T. Siemankowski I couldn't find much on - mostly refs to this book. The book says he is in the dept of science education, so he may well not be a geologist, somewhat supported by this.

Civil liberties and terrorism

This one *isn't* science and it definitely *is* my personal opinion on some political issues. Recently, I've discussed (in the real world) our goverments attempts to bang people up without trial, on the grounds of vague terrorist threats. To which I would say They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety following Benjamin Franklin, Historical Review of Pennsylvania, 1759 (found here). After the end of internment, the IRA were still killing people and we didn't need these powers. Now, terrorists have killed *no-one* in then UK for years and sudddenly we need house arrest. No we don't.

Read the Liberty briefing on it.

BTW, I don't believe in some conspiracy, vast or otherwise, to take these liberties away. A more plausible explanation seems to be that the politicians would be dreadfully embarassed if there was some attack, and they hadn't been pushing the boundaries of what is permissible to try to stop it. That is an ignoble motive. [Don't you think you should soften that a bit, says my wife. Otherwise you're pontificating. Well, I'll leave it].

[Update (as I'm writing this): the govt have finally backed down partially and made the house arrest dependent on a judges say-so not the govts. Listening, over the past few weeks, to ministers on the radio explaining why this was really not possible made me want to bash my head against the wall because of its total illogic. Now they have essentially confessed they have been lying to us for weeks.]

2005-02-27

Looking at: www.globalwarming.org

In my last post I looked at FOE's climate stuff and commented. I said I'd look at the "dark side" too (there are no prizes for guessing where my sympathies lie, but I'll try to be honest anyway). I struggled to find something sensible to analyse. Exxon's search engine found not a single match for "global warming" on their pages, so it looks like they've ducked out. In the end I settled for the Cooler Heads Coalition & their website, http://www.globalwarming.org/, though I'm not sure this is what I really wanted.

Top pic: two laughing children in a bush. Motto: be happy? be irrelevant? Not sure.

They don't have quite such a clear policy section as FOE, but if you go to resources you can find Global Warming In Brief - Q&A so I'll look at that. Its dated November 2000 (though the copyright notice is 2004), but presumably they still consider it up to date. In fact, leaving it un-updated from 2000 may be a deliberate ploy: there is a lot of good research since then, most of it going "against" them and what they write. If challenged, they can perhaps just say "oops we forgot to update it". I'm going to measure it against current science.

So we have: under the header (theirs in italics, mine in std):

Is global warming occurring?



According to Accu-Weather, the world’s leading commercial forecaster, "Global air temperatures as measured by land-based weather stations show an increase of about 0.45 degrees Celsius over the past century. This may be no more than normal climatic variation...[and] several biases in the data may be responsible for some of this increase.". This is a bit weird, why ask accu-weather? They don't do climate monitoring. The true answer is about 0.6 oC, and studies show that its probably not all natural, and that biases (if they mean urban heat island) are small.

Satellite data indicate a slight cooling in the climate in the last 18 years. These satellites use advanced technology and are not subject to the "heat island" effect around major cities that alters ground-based thermometers.. This was written in 2000. The satellite record starts in 1979. 1979+18 is not equal to 2000. They have missed some years out... why? For the std septic reason: the satellite record (S+C version) shows cooling if you take the trends up to about 1996-7. If you take the trends past then, it shows warming. If you take the record to end 2000, the warming is 0.047 oC/decade. So, they are lying. The UHI stuff, as noted before, is spurious: http://en.wikipedia.org/wiki/Urban_heat_island for more

Projections of future climate changes are uncertain. Although some computer models predict warming in the next century... well no, *all* the models predict warming these models are very limited. The effects of cloud formations, precipitation, the role of the oceans, or the sun, are still not well known and often inadequately represented in the climate models --- although all play a major role in determining our climate. There are uncertainties, true. The models are as likely to underestimate change as overestimate it. And... when did you notice them make the same caveats about economic models? Scientists who work on these models are quick to point out that they are far from perfect representations of reality, and are probably not advanced enough for direct use in policy implementation. Dubious. Interestingly, as the computer climate models have become more sophisticated in recent years, the predicted increase in temperature has been lowered. Very dubious indeed. The 1.5-4.5 oC range for doubled CO2 didn't change much up to the SAR; by the TAR it had increased somewhat.

Are humans causing the climate to change?



98% of total global greenhouse gas emissions are natural (mostly water vapor); only 2% are from man-made sources. This is standard septic nonsense. See water-vapour-is-not-dominant.

By most accounts, man-made emissions have had no more than a minuscule impact on the climate. Although the climate has warmed slightly in the last 100 years, 70% percent of that warming occurred prior to 1940, before the upsurge in greenhouse gas emissions from industrial processes. (Dr. Robert C. Balling, Arizona State University). I don't think thats true: http://www.grida.no/climate/ipcc_tar/wg1/figspm-1.htm. But more than that, they are ignoring the vast bulk of attribution analysis which say things like "Statistical assessments confirm that natural variability (the combination of internal and naturally forced) is unlikely to explain the warming in the latter half of the 20th century".

A Gallup survey indicated that only 17% of the members of the American Meteorological Society and the American Geophysical Society thought the warming of the 20th century was the result of an increase in greenhouse gas emissions. I guess this may be true, but unsourced and with no way to tell what the actual question was, I wouldn't trust it.

If global warming occurs, will it be harmful?



The idea that global warming would melt the ice caps and flood coastal cities seems to be mere science fiction. A slight increase in temperature -- whether natural or mankind induced -- is not likely to lead to a massive melting of the earth ice caps, as sometimes claimed in the media. Also, sea-level rises over the centuries relate more to warmer and thus expanding oceans, not to melting ice caps. The idea that GW would melt ice caps is entirely reasonable. It won't happen in a hurry - centuries for Greenland - though. It does correctly point out that much of the warming is predicted to come from thermal expansion... but so what? Are we suppose to say "this flood is OK because its from thermal expansion not ice caps"? Weird. Recent research (it is fair that they didn't take this into account) does suggest that we are not far (decades perhaps) from irreversibly setting Greenland on a course to melt. It still wouldn't be quick, but it would commit us to 5m rise in 200-500 years.

Contrary to some groups' fear mongering about the threat of diseases, temperature changes are likely to have little effect on the spread of diseases. Experts say that deterioration in public health practices such as rapid urbanization without adequate infrastructure, forced large scale resettlement of people, increased drug resistance, higher mobility through air travel, and lack of insect-control programs have the greatest impact on the spread of vector-borne diseases. As far as I can tell, they are right about that, though this isn't my area.

Larger quantities of CO2 in the atmosphere and warmer climates would likely lead to an increase in vegetation. During warm periods in history vegetation flourished, at one point allowing the Vikings to farm in now frozen Greenland. Could be, and to be fair there certainly will be some winners from GW as well as some losers. But theres a lot of stuff they are omitting here - ecosystem responses to T change tends to get predicted as -ve not +ve in general.

Overall: poor. On the science: is GW occurring, and are we to blame, their stuff is a woeful summary of current state-of-play. On will-it-be-harmful (which should be their strong suit) they do better.

[Oops: it looks like I stopped after 3 headers and omitted the policy bits. Well, I'm sick of them for now, tomorrow maybe... :-)]

2005-02-22

Looking at FOE's "Energy and Climate Change"

There is a certain vein of thought that says that "both sides of the global warming debate fling around wild inaccuracies" and so neither can be trusted. This is a tempting point of view for people who feel vaguely guilty but would rather like an excuse for not doing anything or trying to find out the science. In fact (as I've argued before) the state of discussion is better characterised by a vast weight of science in the middle, with small but loud extremes at each end. I've seen it recently argued in comments at RealClimate (see e.g. comments 27 and 34 to this post) that most of the extremism comes from the anti-GW crowd. So... I thought I would examine some recent stuff from Friends of the Earth - who are really quite environmental - to see what they say. Specifically, I'll pick their Energy and Climate Change document, since its conveniently available. What do we see?

Front cover: a hurricane from space (I think; it might be a visualisation of model output). Presumably there to put the idea of dangerous weather in your mind.

Page 2: text starting "Top scientists agree – climate change is real, it’s happening and it’s time to take action to stop it." As I've argued elsewhere, the first two are OK but the vital point - time to take action - is more controversial. I don't have a firm opinion myself, and indeed nor am I sure whether its up to scientists - top or otherwise - to be deciding. "... the burning of fossil fuel energy is largely to blame for the climate changes we are now experiencing worldwide." Fair enough, though what the changes are has been left undefined.

Page 3: graphic showing split of energy use: about 1/4 transport, 1/4 domestic, 1/2 industrial.

Page 4: Headlined "Climate Change Hurts", presumably to justify point 3 above. "An overall rise in average global temperatures is changing the world’s weather. Scientists use complex computer models to predict what may happen. Rising sea levels, caused by melting glaciers and the thermal expansion of sea water, will lead to the flooding of huge areas of lowlying nations like Bangladesh. Extreme weather events like floods and storms may be much more common across the world, devastating homes and livelihoods.". Reasonably fair. Sea level is predicted to rise 0.5m by 2100-ish, which (I presume) won't flood huge areas. Extreme weather *may* be more common... or may not. Examples: NH sea ice thinning by 40% (probably scaled back by more recent publications, but fair enough); spring 3 weeks earlier, possible problems for plants (true; though some people might welcome an earlier spring); higher T bleaches coral.

Page 5: Picture of severe rainstorm in New Orleans, captioned something like "over the past 30 years the number of extreme weather events has trebled". Very dodgy. Economic damage may have trebled, but not the events. See IPCC: "Some important aspects of climate appear not to have changed... Changes globally in tropical and extra-tropical storm intensity and frequency are dominated by inter-decadal to multi-decadal variations, with no significant trends evident over the 20th century. Conflicting analyses make it difficult to draw definitive conclusions about changes in storm activity, especially in the extra-tropics... No systematic changes in the frequency of tornadoes, thunder days, or hail events are evident in the limited areas analysed." The temptation to try to link nice big weather changes - rather than small-sounding temperature changes - to GW is too strong, it appears.

Page 6: "Costly energy": fossils finite and problems; vested interests from energy companies; nuclear not the answer. Nuclear power is certainly hopelessly uneconomic (even now, given oil price rises?) in the UK, making that obvious was a benefit of privitisation, not that it stops the govt propping it up. Note the slight contradiction between worrying about climate change and fossil fuels are finite. Also text box: "There is enough coal to last for around 200 years but to avoid climate change we must not use it.". True. But that means fossil fuels aren't finite enough, from the climate POV...

Page 7: oil-slicked beach photo. Motto: oil is evil, in the wrong place.

Page 8: Clean, green future. Benefits, possibilities, examples of renewables.

Page 9: photo of house with PV solar cells on the roof. "Sunny delight: Susan Roaf lives in an ordinary-looking, six bedroom house in Oxford with extraordinary energy saving thanks to south facing windows, triple glazing, solar panels and good insulation. It costs £120 for a year’s energy and produces only 140 kg CO2. (A similar sized poorly insulated house produces 4,000-5,000 kg CO2 per year)." No mention of the economics of the PV system, but you can find it here (scroll down). By my calculation, the PV roof is producing electricity worth something like 1% of its installation cost per year. Thats not economic as it stands.

Page 10-13: What you can do. Various sensible suggestions, including "If you can only do one thing, then keep putting pressure on the decision makers".

Page 14: Friends of the Earth’s Climate Campaign. OK.

Page 15: Energy and climate change directory. OK. Links include IPCC, and (no surprise) none of the septics.

Overall: a bit thin on the economics; over-emphasises the certainty of dangers but not vastly so. Definitely not neutral. And yet... the public do need to be alerted to the potential dangers of climate change, and this tries to do so. Anyone who wants the full IPCC picture can just read it themselves so there is not much point reproducing it.

Coming soon... an analysis of the Dark Side. If I can think of something suitable.

2005-02-21

Lost. One submarine. (Doesn't) answer to the name "autosub".

We seem to have lost autosub, as the Guardian reports today. Is this a Beagle II moment? Its hard to know. I always found the fact that it was powered by a gigantic number of "D" cells rather funny, and its impossible to resist jokes like "oh they probably used some cheapo ones they got from a bloke on the market". I'm being unfair, of course.

OTOH, using autonomous vehicles under the ice shelves is fun (I wanted them to go under the sea ice to profile the ice thickness in winter; sadly thats not on the cards yet; if Autosub had stuck to sub-sea-ice and kept away from sub-ice-shelf, they could have got it back). "Gliders" are probably the future, though navigation under ice is tricky.

He now has Isengard to fear as well as Minas Tirith

He now has Isengard to fear as well as Minas Tirith.

You can have a point if you can work out why I've posted this, and another for the details. It may be too easy, since I didn't cheat :-) Reading http://www.inkstain.net/planetfleck/ may help.

2005-02-18

The Science Museum

The Science Museum it calls itself and I think of it as such, but I know that there are others in the world as well as the one in London and I'm told that others are quite good too... Its half term, so I took Daniel and Naomi and Mr Weasel to South Kensington for the day. Its a fair trip: Coton to Cambridge, train to Kings Cross (full:we sat on the floor - on the way back even more full and we struggled to find room on the floor!), underground to South Ken, then the long subway to the Museum: about 2:15h in all.

But its worth it. Not only does it have some great galleries, it has some great play areas (ahem, I mean of course "educational facilities cunningly disguised as play"). Sadly the main hall (most of the steam engines) was shut for refurb (during half term? are they mad?), and they were on strike on wednesday, which probably contributed to the crowds - the LaunchPad was very crowded, the Garden less so but we had to queue a bit. And the children (7 years old) enjoyed these two areas so much we barely had time to wander the galleries. Which brings me on to my rant...

When I were a lad, ee, we didn't have none of this play areas, we had galleries of models of the different sorts of steam engines and you could twirl the knobs and watch them work. I have dim and distant memories of this (and of slam-door trains filled with cigarette smoke) - overlain with more recent memories of doing it as an adult. Sadly those galleries are the ones shut for refurb. But the Wellcome wing isn't shut, and that wing is really really weird. A large bit of it is the IMAX cinema - fair enough I suppose, though rather peripherally science, more entertainment - and it does seem to make walking round the rest of it tricky, with odd changes of level, and no stairs where you would expect stairs. The odd bit is the funny crawling lights with messages on (Daniel loved it, but I can't see the point) and the pattern pod, and the "games" bit upstairs.

The pattern pod: intrinsically, a nice idea. There is a computer touch-screen that makes 5-symmetrical versions of the dots you draw. Nice; always overcrowded. There was a "fractals" thing with drop-in keys that grew patterns on the screen - but always the same (and no explanation). And there are some foam-rubber magnetic Penrose Tiles for you to tesselate. And there is a computer-touch screen to guide you through all of this... which is where I start to get mad. Because the touch-screen explanation is hopelessly, laughably inadequate. It mentions the Penrose tilings, but doesn't tell you how to do it. There are *only two pages* of screen, which only contain a few words, about this. The lost opportunity is terrible. There is no explanation of their properties; of the history; etc etc. Why not? There would be space in the machine for endless sub-levels of explanatory text for the interested. And don't tell me its because they are short of money: the Wellcome wing drips money (or did when first done; its fraying at the edges a teensy bit). Possibly the idea is that rather than feeding people science, you allow it to infuse gently. Possible... but I don't think its sensible. Not having a more detailed explanation available, when it could be, unobtrusively, just doesn't make sense.

Then I dragged them off under protest to look at Puffing Billy and the Rocket and they loved that too.

2005-02-17

Trying to create mountains...

James Annan has a very nice post to sci.env that I'll quote in its entirety. Hey, it beats thinking for myself. Although, to briefly think for myself, I should say that I have rather less sympathy for M&M than James does. His original is available through google here. This is all in the context of McIntyre waffling about "due diligence":

James says:

Steve McIntyre has found a molehill and is doing his best to make a mountain out of it. I do not mean to be unduly critical of him in those words - I understand the frustration that can occur when one finds what appears to be a significant problem, only to be brushed off in a manner that seems to be rude and dismissive. IMO (and IME), scientists are probably no better and no worse than other types of people in this respect, they have their own egos and prejudices and do not like to be told that they are wrong. My own experience in this area is already in the public domain and does not need repeating again.

Although it is only natural that McIntyre should try to talk up the importance of his work, he seems to completely misunderstand the scientific process in his talk of audit trails and replication. Sure, work should be reproducible, and it is embarrassing for those who find errors in their work or, what is worse, have errors pointed out by others. Peer review is indeed a rather superficial check on the validity of the work, and can certainly be subverted by a determined effort at dishonesty. But scientific research is already subject to a far more relevant and stringent test than he advocates. It is an intensely competitive and adversarial process, with rivals continually trying to improve on each others' work. One could even characterise this as "prove each other wrong", but generally it takes the form of incremental advances that modify the previous results, rather than completely overturning them. Results that are strongly divergent from the existing status quo will certainly be carefully checked in subsequent research. But, except in the most exceptional cases, merely checking that a rival had done their sums right is very unlikely to reap any real benefits - even if some error or inaccuracy is found in the calculation or description, it may well not impact significantly on their results [1], and if no error is found, then this replication still provides no assessment of the validity of the underlying assumptions and methodology of the work. However, the alternative - which is how science actually works - of developing new and improved methodologies, more accurate data sets and better models actually provides a much more rigorous check of the correctness of the underlying assumptions and conclusions of earlier research, which is, after all, the main goal.

I have no direct knowledge of the IPCC process, but McIntyre's picture of climate research consisting of a cosy coterie of pals all working towards supporting a "consensus" and patting each other on the back certainly doesn't ring true with me. The "consensus", such as it is, represents the equilibrium in a dynamic tension with different people pulling in different directions. Taking the example of the climate's equilibrium response to 2xCO2, the consensus view of ~2-6C is not because everyone one is trying to agree on this range, but because no-one has yet found any credible cause for disagreement, despite numerous alternative models and methods (the range itself represents the amount of disagreement, to a certain extent). We can see in eg the recent climateprediction.net results, and the comment published on realclimate.org, evidence of the dynamical tension underlying that consensus view.

So while I have some sympathy for McIntyre's cause, I disagree with his conclusions. While his molehill should not just be ignored, it must also be kept in perspective.

James

[1] It may be worth noting James's Law of computer bugs - the undiscovered bug probably doesn't matter. FWIW, I found a bug in code I used for a recent publication, and correcting it just makes the results marginally more accurate. The bugs that made the method fail completely were corrected at a much earlier stage :-)

2005-02-15

GNU data language

GDL is a free IDL (Interactive Data Language) compatible incremental compiler (ie. runs IDL programs) by, mostly, Marc Schellens. Check out its homepage at
http://gnudatalanguage.sourceforge.net. IDL is a registered trademark of Research Systems Inc and is what I use at work for all my data analysis and plotting, its tremenously useful. Its fast and powerful, allows compile-on-the-fly, etc... well, read about it on http://www.rsinc.com/idl/ if you want to. The only thing wrong with IDL (apart from needing /cell_fill on polar stereo projections...) is that its quite expensive. Which means that sharing code with people that don't have it won't work. But along comes GDL... or at least, its coming.

The current (0.8.8) version says it features:

Full syntax compatibility with IDL 6.0

ALL IDL language elements are supported, including:


* Objects,
* Pointers,
* Structs,
* Arrays,
* System variables,
* Common blocks,
* Assoc variables,
* All operators,
* All datatypes,
* _EXTRA, _STRICT_EXTRA and _REF_EXTRA keywords...


The file input output system is fully implemented
(Exception: For formatted I/O the C() sub-codes are not supported yet)

Which all sounds very nice. I don't need it, because I have IDL, but I decided to try downloading it and seeing if I could make it work. First I needed to download plplot, which it relies on, and make that; OK. Then make GDL. This proved a bit problematic as I lacked a few things (hdf; ImageMagick; etc) that it didn't actually need but wanted. Sadly it wasn't clever enough to turn these off in the configure and I had to manually, but having done that I get an executable that runs and understands usual IDL syntax. Some things clearly work; others (.run; the normal-random-generator randomn) don't. Plotting to the z-buffer didn't work.

So it looks to me that if you can't afford IDL, it might well be worth looking at GDL, but probably some rather important bits are missing at the moment.

Traffic etc

My readers (and investors :-) may care to know that this blog just broke through the 200 visits a day barrier for the first (but surely not the last) time, probably because of the many links people made for the Moberg et al post - thanks. I was initially somewhat unsure about whether I'd continue this but the steadily increasing traffic, and my own enjoyment, means that I will. One thing that isn't currently too encouraging - no surprise - is the google advertising revenue, currently between $0.50 and $1.00 :-(

The Moberg post has now been updated and improved on RealClimate, though if you've read the version here you won't find a lot new. It is so much easier writing posts for this blog than for RC - standards being higher there, mistakes rather more visible and chattiness being deprecated. The RC post ended up using a GFDL figure from wikipedia so that post becomes GFDL - we might make them all that way.

2005-02-13

2004: 4th warmest year on record

2004 was the 4th warmest year on record, says NASA - though you knew that already since it appeared on RealClimate. What I hadn't quite realised, but NASA writes out in nice large letters so even simpletons like me can see it - is that they go (1) 1998, (2) 2002, (3) 2003, (4) 2004. Which is just the teensiest bit odd and possibly worrying (though the trend is clearly downward over the last 3 years - clear cooling - hah!), because even if the std GW projections are spot-on (of course they are...) natural variability should still jiggle the years around a bit (well, as they did after 1998 I suppose). And if you believe various reconstructions (e.g. last post on Moberg) then its the warmest in 2000 years.

Blogshares

Lubos posted a somewhat megalomaniac (can you be *somewhat* mega?) comment asserting that he was "the majority shareholder" of this blog (see blogshares). I'm not quite sure what weirdness this is, but fear not folks, my editorial independence is on no danger from this hostile takeover.

Anyway: blogshares: it says the value of this blog is B$3,411. And my share price is above $2. Does this mean anything? By contrast, Deltoids price is B$0.20, yet his traffic is far higher, so either I have a golden future ahead of me... or the numbers mean nothing. Errr... or something else...

2005-02-11

Moberg et al: Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data

The 10th Feb edition of nature has a nice paper Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data by ANDERS MOBERG, DMITRY M. SONECHKIN, KARIN HOLMGREN, NINA M. DATSENKO & WIBJÖRN KARLÉN
(doi:10.1038/nature03265). It is sure to attract a lot of attention, but I'm writing this without having read reviews, except the News and News&Views in Nature. Having read what I've written, I suspect that this post requires a lot of background knowledge to make sense of... do feel free to ask questions, here or on sci.env.

What the paper does is to use wavelets to do the temperature reconstruction. It arrives at a more variable record than before, but the temperatures since 1990 are still the warmest in the last 2000 years. something for everyone...

The novel thing about this paper is the wavelets. What they have done is to combine the high-frequency (< 80 y) signal from tree rings with the low-frequency (> 80 y) signal from lake sediments and other such non-annually resolved proxies. This does two things that they think are good: it allows the non-annually resolved proxies to be used (previous, e.g. MBH98, used only those with at least a value each year, to allow calibration against the instrumental record; this study can use data that only provide 50 y means); and it throws away the long-term signal from the tree rings, which they don't trust. There *are* problems with the long-term signal from tree rings, as I understand it, but I'm not sure that throwing all that away is such a good idea.

The result is a more long-term variable signal than, e.g., MBH98. They end up with two "warm peaks" in the smoothed record in 1000 and 1100, at about zero on their anomaly scale, and with annual peaks up to +0.4 oC or a bit less; the most recent data from the instrumental record post 1990 then peak at +0.6 or a bit more, on the same scale. Their minimum about 1600 (the "LIA") is then about -0.7.

On the politics side, this is bound to stir up interest, since the "hockey stick" has become so totemic. Moberg et al note the disparity with MBH (and Mann & Jones 2003; incidentally there is a nice chain of papers: Moberg et al; Jones and Moberg 2003; and then M&J03 which links Moberg to Mann) and unsurprisingly prefer their version, and quote von S in their support, again no surprise. I strongly expect to see unbalanced quotes from this paper in the septic press, with the increased variability emphasised and no sign of "We find no evidence for any earlier periods in the last millenia with warmer conditions than the post-1990 period - in agreement with previous similar studies (1-4,7)" where (1) is MBH98, (2) is MBH99, (7) is Mann and Jones '03. The "News" article in Nature explicitly rejects the idea that this means we're not causing the current warming. And it quotes von Storch: "it does not weaken in any way the hypothesis that recent observed warming is a result mainly of human activity".

Now for my concerns about the paper. I'm no palaeo person, so these comments are not to be taken too seriously, though I have elsewhere attempted to make sense of some of these issues:

I am slightly doubtful that the wavelets stuff has added much to the mix, though it looks impressive. As far as I can tell, they use the wavelets to merge the high-frequency data from the tree rings with low-frequency data from the other sources, which have lower temporal resolution. But... that means the low-res proxies are doing all the work, and the tree rings are just adding a pretty-looking fringe of noise that your eye reads as sort-of error bars. Or have I missed something?

Second, the lack of spatial averaging seems a bit unfortunate, though they say it doesn't matter.

Third, because they have used the wavelets, they end up with a non-dimensional signal which has to be normalised against the instrumental record from 1859 to 1979. So if (for example) their reconstruction was too flat in that period, the renormalisation would pump it up in the pre-industrial period. Or if too noisy, it would get toned down. The adjustment is done to match "mean value and variance" but (being in Nature) this is a bit brief: do they mean the variance of the smoothed or full series? If the full series (which is the default I suppose), then most of the variance is probably coming from the interannual variations of the tree rings, *but* the bit thats really interesting is the long-term signal. If its the long term signal that is being matched, then you only have 1-2 dof's to match in the period 1859-1979.

Refs




  1. EurekAlert: Natural climate change may be larger than commonly thought
  2. Nature: news: Past climate comes into focus but warm forecast stays put; News & Views; Article (first para); nb Nature content requires subscription.
  3. Quark Soup (inc graph)


[Correction: v1.0 of this omitted the text "80y) signal from tree rings with the low-frequency ("]

2005-02-08

Astonishing train ticket prices

I had to go to the Met Office in its shiny new Exeter building today. This involves getting up at 6:30, catching the 7:15 from Cambridge to Kings Cross then the 9:05 from Paddington to Exeter. Guess how much the return ticket by train cost? Bought then-and-there, from the station? Can't guess? I bet you can't. The answer is a truely mind-boggling £160. Fortunately my employer is paying that not me.

Now... I do my best to be eco-friendly and take the train not drive when possible. But not everyone is so keen; and not everyone has their employer paying. How can we expect people to choose the train when the prices are that high? I think, though due to shortness of time and a queue behind me I didn't have time to check, that the main price element was the cost of the 9:05 out of Paddington, this being priced to gouge the business folk. But oddly enough, that train was nearly empty, as who wants to pay that kind of price? They would make more money with prices half as high but trains half full instead of 95% empty. For £160 I could get to Nice and back twice, or to Vienna once and a bit. In fact, it would be both cheaper and quicker (err... if we went back to pre-panic checkin times) for me to get there if the Met Office had relocated to Nice not Exeter...

2005-02-07

An odd post at Prometheus

Roger Pielke has a rather odd post over at Prometheus. To me, it seems that he is riding his hobby horse (the "honest broker") rather hard. What is he complaining about? That the recent steering committee report of the Exeter conference: Avoiding Dangerous Climate Change mentions stabalising (equivalent) CO2 levels:

Limiting climate change to 2 deg C implies stabilizing the atmospheric concentration of all greenhouse gases. The CO2 concentration must not exceed 500ppmv, if the climate sensitivity is 2.5 deg C. Global emissions would need to peak in 2020 and decline to 3.1 GtC/year by 2095... Major investment is needed now in both mitigation and adaptation. The first is essential to minimise future impacts and the latter is essential to cope with impacts which cannot be avoided in the near to medium term.”.

(Thats quoting RP quoting the report; if you want to read the uninteresting bits in the ..., then see the report itself). But this is innocuous (at least the bit before the ...): its just a statement of fact (or rather, of the current best-guesses at fact). RP concludes:

If the Exter conference is indicative of the direction that the IPCC will be taking in its Fourth Assessment Report, then it will be remembered as a key milestone in the continuing evolution of the IPCC from honest broker to political advocate.

Which is weird. Because it wasn't an IPCC conference at all. It was sponsored by DEFRA. The steering committee was chaired by someone from the OECD and none of them list IPCC affiliations; the report that RP dislikes so much is also pretty innocuous. The last sentence that RP quotes looks like it was stuffed in by the politicoes, but quite why he blames IPCC for that I don't know. Adding the "If..." just about saves it, but his thrust is clear and I simply can't agree with it.

If you read the keynote presentation by Pachauri (who identifies himself with IPCC) you find "defining dangerous is a value judgement" and "Can a temperature target capture the limits
dangerous?" (unfortunately I don't know exactly what he said there, as I only get the bullet points of the presentation) - these are exactly the points that RP himself is keen on, but he gives Pachauri no credit for this.

In fact, it all looks like at attempt to fulfill the second part of his prophecy:

So if the conference reports scientific understandings and uncertainties for emissions stabilization scenarios related to (a) a magical instantaneous ending of CO2 emissions, (b) unrestrained emissions (a maximum scenario), and (c) everything in between, then it would clearly give policy makers a sense of what science can say about stabilization scenarios and their consequences. This information would allow policy makers in the the UK, or any other country, to debate and discuss the concept of "dangerous climate change" and, if desired, work towards a political consensus. Such a perspective would be a valuable outcome of the meeting.

But if the meeting results in a recommendation for stabilization at one particular concentration level over others, and increasingly we hear calls for a 2 degree/400 ppm target, then the meeting will have devolved into an exercise in political advocacy under the cover of the authority of science and scientists.


And if you read the report, it fulfills part I of his prophecy. But you wouldn't guess that from his follow-up post.

2005-02-06

The real world and the virtual world

Non science this time.

While playing computer games (not that I waste much time that way of course...) I sometimes wonder where all the maids, gardens and sweeper-uppers are. The virtual world is always so clean (apart from the gore, of course) and you never have to dust or tidy.

Things like that strike me forcefully when I spend an hour down on the allotment and manage to dig over a few square meters of turf; or this afternoon I spent an hour or more demolishing the old compost heap and putting in a new hopefully rat-proof one (no rats in the compost online), then tidying the soil and sowing new grass seed. Virtually, a few clicks of a mouse would have done all that!

Which must be why I often find myself of an evening typing bright shiny words onto the web rather than face the chore of tidying up at home.

Meanwhile, Miriam is practicing Etude Tableau #1 opus 33 by Rachmaninov, which is part of a different virtual world.

2005-02-04

The Economist on Climate Change

This column was going to be called "Dishonest Economist" (it sort of rhymes) but I thought that was too provocative. The 5th February edition of the Economist has a story
Hotting Up (subscription required) subtitled "The debate over global warming is getting rancorous". The first thing wrong is the subtitle, because its wrong. The debate isn't getting more rancorous - in fact if anything it does seem to be settling down to the consensus view. But the Economist doesn't like that, so it is pretty well resorting to the old favourite, stir up confusion and retreat in a cloud of ink. I think this is because climate change doesn't fit into their worldview - it would complicate their lives so much if they had to take account of climate externalities, so they would rather hope and argue that there is no problem.

Beginning the article with a quote from the egregious Crichton (you get 1 point if you can spot the joke there, other than Crichton of course) is the next mistake (or perhaps a pointer - are they trying to tell us that their article is a potboiler?).

Continuing, the article says very little for a while, before supplying a nice quote from Trenberth over the Landsea affair: politics is very strong in what is going on, but it is all coming from Landsea and colleagues. He is linked to the sceptics. I'd like to know what T means by that: does he mean the Michaels paper, or something more?

Overplaying MM05 comes next (sigh) followed by a misleading section on the failed Castles and Henderson critique - they don't even mention the IPCC rebuttal.

However, there is quite a nice section on what was wrong with the Climate Change section of Lomborgs "Copenhagen consenus" project.

All in all, a bit of a waste of pages in the paper. Disappointing.

2005-02-03

Einstein restored faith in the unintelligibility of science

The title is a quote from "Einstein as icon" by John D Barrow in the 20th Jan edition of Nature. I really like it. It follows on, in the article, from a discussion of other major figures - Newton, Darwin - and the comment that Darwins work was too well known. People thought they could understand what Darwin saw saying. But almost everyone agrees they don't understand Einsteins work.

And it reminds me, irresistibly, of the wise words of Gavin Schmidt on the launch of RealClimate:

Climate science is one of those fields where anyone, regardless of their lack of expertise or understanding, feels qualified to comment on new papers and ongoing controversies. This can be frustrating for scientists like ourselves who see agenda-driven 'commentary' on the Internet and in the opinion columns of newspapers crowding out careful analysis.

And Gavin is correct. Any old fool - politician or physicist - with almost no knowledge of the issues seems to feel free to comment. Where is our Einstein?