2006-01-30

More Hansen

The "Hansen gagging" story has been around a bit... now I find (via Roger on sci.env) this: I am writing in response to several recent news articles indicating that officials at NASA may be trying to "silence" Dr. James Hansen, the director of the Goddard Institute for Space Studies. It ought to go without saying that government scientists must be free to describe their scientific conclusions and the implications of those conclusions to their fellow scientists, policymakers and the general public. Any effort to censor federal scientists biases public discussions of scientific issues, increases distrust of the government and makes it difficult for the government to attract the best scientists. And when it comes to an issue like climate change, a subject of ongoing public debate with immense ramifications, the government ought to be bending over backward to make sure that its scientists are able to discuss their work and what it means. And so on.

[And now checking, I see Prometheus has this already]

"Rising concentrations of greenhouse gases may have more serious impacts than previously believed, a major new scientific report has said"

Umm... whats happened? (I wondered to myself, lying fuzzy in bed at 8 a.m. listening to this stuff on the R4). Did they publish the AR4 a year early with major revisions to the conclusions? No. All this is about (source: BBC) the conference report from the Exeter conference in Feb '05. So (a) its not news; anything in the report (should!) have been said a year ago; and (b) I don't recall the Exeter conf saying much new at the time, either (backed up by the RC post I wrote at the time). And is this a "major report"? Probably not.

The Beeb (check out the video...) picks up on the sea level rise from Greenland: It fears the Greenland ice sheet is likely to melt, leading sea levels to rise by seven metres over 1,000 years. OK, this is fair enough (depending on your scenario it might be more or less than 1000 years, and it might not all be gone for quite a bit thereafter, but its fair enough to be going with... say 5m in 1000 years). But again, its not news, its pretty well in line with the TAR (isn't it? I can't say I've bothered to check). 5m in 1000y is 5mm/yr which is more than the 2-3 mm/yr we have at the moment (and is effectively additional to it) and presumably wouldn't be linear but would come in spurts. Current (and TAR-like) projections for Greenland for the 21st century are much smaller - about 40 mm - which is about right: increasing T increases ppn, but also ablation, so past some (TA-DA!) "tipping point" the SLR contribution from Greenland goes up a lot. But... that pushes the problem a way into the future. Is it reasonable for us to "commit" our descendants to a melting Greenland? (assuming the std.science is correct, and no magic is found, this is what we would be doing).

What else? Above two degrees the risks increase very substantially, involving potentially large numbers of extinctions or even ecosystem collapses. This is onto the bio stuff: could be plausible, I can't comment usefully (I could make it up if you like...). This is linked to the 2oC target the EC has; see my RC post. So, supposing you didn't want to break +2oC (with probability X) you need to limit CO2 to Y; X=60% apparently translates into Y=450 ppmv; since we're currently at 380 my guess is we'll go through 450.

And then it got onto Slashdot which (finally) prompted me to get a slashdot ID and post a comment. See if you can find it. I don't think I'll pursue commenting there... there is just so many comments, so much junk (though some good). This one I quite liked, though others didn't.

[Update: RP has a link to the report pdf itself (I haven't read it yet). Sadly RP also has some dumb comments by Peiser; still, no-one is perfect :-) ]

Gazillion year old ice

Before the post, a quick joke, brought on by the word "Gazillion": Bush in the White House; an Aide says "Mr Prez, I'm afraid that 3 Brazillian soldiers were killed in Baghdad today". Bush is shocked, to an unlikely degree, and the surrounding Toadies are surprised. Bush asks: "Just how big is a Brazzillion, anyway?" (here is one source). And if you didn't like that, you can try The Onion.

But onto more serious matters. Nature has a report about some new ice cores from Antarctica (thanks het, who has more links), and something of a race for the first "million year old ice". Kohnen Station in Antarctica's Dronning Maud Land has a new core, and Preliminary tests show that the bottom of the core might be as much as 900,000 years old. They sensibly hedge their bets with The age will have to be confirmed in their laboratory back in Germany, "but we're pretty confident,". But no sooner is this in, than Japanese scientists working at the Fuji Dome Antarctic research station said they have retrieved an ice core sample that could be up to one million years old (again, hedged). If you're wondering where all these various cores are, then look at the pic; original here.

But the important thing about ice is not how old it is (if you want super-old ice, go mine a comet; mind you that might be quite expensive too...) its how well preserved it is and its stratigraphic sequencing. There are, if you look closely at the Nature report, hints of this: The Kohnen core should also provide more detailed climate evidence than the one from Dome C, at least for more recent times. In the upper parts of the core, ice accumulated more than twice as fast as at Dome C, so it will be easier to distinguish between ice layers laid down in consecutive years. The ice at the bottom of the core, however, seems to be at least as old as that at the bottom of Dome C, so it must be very compressed. Err yes. So we'll get a more detailed *recent* record (which may have some value, e.g. looking again at D-O events in the Antarctic) but that could have been got from a much shallower core. And we'll get a record from a different sector (nice to see how things co-vary). But... a more detailed recent record implies a less detailed deep record; which is probably the greatest interest. The EPICA core goes down reliably to 780 kyr; does the Kohnen core provide useful info for [780,900] kyr? It will be good if it does. OTOH, since Kohnen isn't at a dome, the bottom is probably smeared, and very hard to work out where it came from.

And a postscript, on how rapidly things get sensationalised: Researchers dig up million-year-old ice (bad headline, text not so bad). Ditto from physorg.

Torture and Terrorism

From the Grauniad, an interesting article about torture, but its about the Inquisition. The assertion that Torture and execution were always carried out by the secular authorities, not church officials is new to me, and perhaps has modern-day analogies. The interesting bit is the quotes from Very Rev Joseph Augustine Di Noia, attempting to put it all into context. He says:

It is a mistake to torture people. However, torture was regarded as a perfectly justified, legitimate way of producing evidence and it was therefore legally justified. Killing people over ideas, generally speaking, seems to us not to be a very good idea after 2,000 years of history ... and generally we disapprove deeply of this kind of purgation, but it seems to me it is possible to understand it within the context of its times and also to understand it within the sociology of religion, how communities react to threats which they regard to be dire or fatal.


There are things to quibble here. Describing killing people as not to be a very good idea is a bit weak; and the "is" of the first sentence seems to delicately assert that it might not have been a mistake in the past. But the arguement that it can all be understood "within the sociology of religion" makes sense to me. But then, I'm an atheist, not a member of a church that claims to be the One True Faith, and on occaision, claims inerrancy. So is this the new Catholic policy? No Eternal Verities, just religion understood from within sociology and context. Sounds radical.

Moving right along, we come to... Terrorism. Which brings me to Israel's shooting of young girl highlights international hypocrisy, say Palestinians (also from the G). And of course links to the recent Hamas victory (for which I'll refer you to CIP and subsequent). And the demands for Hamas to eschew Violence. Which is total nonsense: *we* don't eschew Violence, and nor do the Israelis (what do you think all those guns, tanks and warplanes are for?). Oh... you didn't mean *Violence* from the dictionary definition... you mean Violence excluding anything we do? And as for the equally slippery Terrorism: The army said the boys planned to throw rocks at Israeli cars, which the military defines as terrorism ah yes, Terrorism is what we define it to be. But shooting dead 9 year old girls definitely *isn't* terrorism ...as long as the right side is doing it, of course.

2006-01-29

Not the bristlecone pines again!

Yes indeed. See this take on science publishing (via Island of Doubt). "My policy with regard to conclusions is to make the maximum plausible claim. It is foolish to leave any unncessary foothold for competitors...". Not only is this close-to-the-knuckle funny, its far more scientifically literate than anything you could hope to find in any UK newspaper.

[Update: I've just corrected my spelling of "knucle". I new it looked rong. Phortunately English is so ezy too spel]

2006-01-28

Fun with hurricane trends?

Over at http://www.eas.gatech.edu/research/candr.htm there is some fun, with Webster/Holland/Curry/Chang disagreeing rather strongly with Gray (also findable via this) over... yes you guessed it, hurricanes and trends. Its all a bit more raw and bloody than usual science correspondence (In spite of his concerns about data between 1970 and 1984 in the WHCC analysis, Gray nevertheless uses data from 1950 to bolster his arguments. Gray presents an alternative hypothesis for variations of hurricane characteristics in the North Atlantic that involves salinity variations; this hypothesis is not substantiated either in his paper or in the published literature. His analysis of the impact of warmer sea surface temperature on the stability of the lower troposphere contains basic errors in thermodynamics. In summary, there is no credence to any of the issues that Gray raises), so worth a quick read. JA's quote from Myanna Lahsen I think also applies.

[ps: I think I found this via SB; but it may have been CB; in either case I can't remember where. Please remind me...]

[pps: Over in Bogota even weirder things are happening...]

2006-01-27

CO2 and SRES

The graph shows recent CO2 changes. Top are the CO2 themselves (monthly, plus 13-month running mean); bottom are change-on-12-months earlier. Data from Mauna Loa; sadly I can only find them up to end 2004. Which means I can't provide a decent answer to SB, who asked about reports that this years CO2 rise was 2.2 ppmv. However, even if it was 2.2 (can anyone find a report, or better still the data?), that looks to be nothing surprising, in view of the past. And its clearly lower than the 1%/y assumed by some of the idealised scenarios. When I find the SRES data I want to look at how the various scenarios look around now.

I find it hard to get too excited about the exact levels for any one year; what matters are the long term trends; for the future, those are clearly Upwards, but by how much depends on economics that are rather tricky to forecast. But T rise (etc) can largely be scaled to CO2 level, rather than date. James Annan (ref lost) pointed out that methane levels seem to be well below SRES trends (indeed this shows them to be currently flat; whether that will continue I don't know).

Meanwhile, JF has a post sort-of about this too, with a vigorous exchange of comments.

[Update: And John Quiggin has a post too. Pure co-incidence... he too appears to be on the it-does-make-much-difference idea, but with the advantage of understanding the economics]

2006-01-23

Dynamical amplification of polar warming

Polar amplification, again. RC recently had a post on this; though now I look again its a teensy bit vague about the actual *causes*. Which I've posted on before. Now along comes... Cai, M. (2005), Dynamical amplification of polar warming, Geophys. Res. Lett., 32, L22710, doi:10.1029/ 2005GL024481. Unfortunately, I have failed to do my duty, which is to carefully read and understand the paper. Maybe someone else will do that and comment. All I've done is skim it. But read on...

This paper presents theoretical and modeling evidence suggesting that the atmospheric poleward heat transport can lead to a polar warming amplification (i) by redistributing part of the extra energy intercepted by the low-latitude atmosphere to high latitudes, and (ii) by strengthening the water vapor feedback in high latitudes. For an anthropogenic radiative forcing of 4 Wm/2, we illustrate that the dynamical amplifier contributes to about 1/4 (1/10) of the total high-latitude (global) surface warming in winter in a simple coupled atmosphere-surface moist radiativetransportive climate model. Budget analysis of the radiation fluxes at the top of the atmosphere derived from IPCC AR4 CGCM climate simulations seems to support the dynamical amplifier theory for the larger warming in high latitudes.


The most interesting part of this is part (ii) - the strengthening of the WV feedback in high latitudes. Its interesting because although many people think its why polar amp occurs, this is the first paper I've seen to assert it. The least interesting is part (i), because thats been done already (and better, from a brief scan) by Alexeev in Cli Dyn (see my prev post). The problem is that Cai is using a 4-box coupled atmosphere-surface moist radiative-transportive climate model to illustrate the dynamical amplification of the high-latitude surface warming due to an anthropogenic forcing. And the WV feedback isn't done properly, The water vapor feedback has been crudely parameterized using an ad-hoc formula Equation 5 to mimic the strong dependency of the atmospheric absorption of longwave radiation to the amount of water vapor. Specifically, the total atmospheric effective emissivity in the model is made of two parts: a constant part e0 representing the absorption due to other gases, such as CO2, and a part that varies as a function of the total amount of water vapor in an atmosphere column. And worse than that, I can't see where they seperate out effects (i) and (ii), so at the end of it all I can't see where they say how important the WV feedback is (if we trusted their eq 5).

[Updated to fix funny char (ctrl-A?) in the Wm/2 that was doing naughty things to the feed, apparently]

2006-01-21

Just eat it!

James Annan has another classic post up, displaying his characteristic incisive wit and complete lack of sentimentality.

According to the 10 o'clock news, its now dead anyway. As far as I can tell, this always happens: great public interest, pointless but newsworthy rescue attempts, and a dead whale. Presumably to be sunk at sea by naval gunfire (to quote the late great Spike Milligan). Perhaps they should just have left it alone: people can never resist the urge to fiddle.

2006-01-20

Sci.env: IPCC understates the risks?

There is an interesting exchange today over at sci.env, which touches on some things I've been thinking about recently. See here for the thread & if you want to know who they are (well scroll up a bit); I'll extract some here and then comment. Both sides are people I respect (well they are on my blogroll) and yet they are in violent disagreement. I had the slightly unsettling experience of reading the first post, thinking "yes thats spot on" then reading the reply and thinking "hmmm, some valid points there too".


> I believe the IPCC genuinely constitutes a consensus, but I believe
> that the consensus severely understates the risks.

> There are several reasons for this. Notably:
> - models are tuned for small signal accuracy and can't capture
> large nonlinearities

I don't really understand what you can mean by this point. The models
perform reasonably well across a wide range of conditions including the
6C cooling at the last glacial minimum, the ~12C annual temperature
cycle (more at higher latitudes), not to mention the basic spatial
patterns in the first place. A 3C temperature rise is not large
compared to the range they've already simulated, and there are good
reasons to expect the models to be largely correct in broad detail.

> - carbon cycle exacerbating feedbacks are not sufficiently attended
> to, and are buried under the rug in the simulation scenarios

Carbon cycle feedbacks have been included in a number of models
(C4MIP), my understanding is that the effects are generally modest, and
even for the outliers it is not something that turns a mainstream
projection into a nightmare. One possible wildcard is a methane burp,
about which I know little but it does on the face of it seem worthy of
consideration.

> - the IPCC seeks the most likely response of the system rather than
> the risk-weighted outcome, which essentially hides the worst cases

Um...no. That's simply not true. It describes the range of outcomes
(according to some rather vague probabilistic statements).

> - most scientists are conservative in personality and don't like
> making a big fuss, so shy away from clear statements of the enormity of
> the risk we face

Well...this may be true but even if so is highly misleading. It's not
"most scientists" who we hear, either in the media or through
assessments such as the IPCC. It's those scientists who make their
opinions forcefully enough who are heard, and I absolutely disagree
that this subset are conservative in personality and do not like making
a fuss.


The point of all this is, what-do-you-tell-the-public. There's no great problem with what-do-you-tell-fellow-scientists: thats easy: you publish your research and they read it, or not (thats not really true either when I think about it: its true within physical climate; but when you start to try to do impacts on ecology, then the Bio's need the phys stuff interpreted). But the public need it all interpreted: they are not going to read the original papers (even if they have access to them).

I have much sympathy for most likely response of the system rather than the risk-weighted outcome (its not technically true: the scenarios are not probability-weighted; but you know how it goes). When I give general-public talks (and you can find the stock one I do, by following a few levels of links from this, if you want to) I downplay the overenthusiasm you find in the media for disaster scenarios, but always with the ever-so-slightly guilty feeling that I may be wrong. I point that out too - I try to mention the uncertainty - but I have the impression that people have problems keeping up with everything and are going to miss the subtle side messages.

2006-01-18

Sex at BAS

James "added 1.5 inches to the crotch length" Annan recently blogged about Sexism in Science (and ref'd some interesting CV stuff). So I thought I would offer my (male) perspective.

In terms of recruitment, we don't seem to be doing too badly. Quite frequently there are as many women as men around our coffee table at work (because the Real Men are too busy researching to come to coffee... ha ha no; coffee time is close to obligatory unless you're John Turner). We get plenty of female candidates, and in the interviews I've done there has never been a hint of bias against (or for) the women. And I'm one of the people working part-time to help bring up children.

OTOH there are no women at all in our senior management structure (or a few, if you lower the seniority bar a bit). Whether this is because its a remnant of previous discrimination, or continuing disc, or innate female unsuitability for senior management I don't know (though I doubt the latter).

2006-01-17

Masquerade

On the plance back from NZ, I got to watch a weird Japanese TV show called "Masquerade". It was very funny, and I've never seen anything like it before. But then I don't watch much TV. The photo is a screenshot: one chap is a basketball player, and the other chap is the ball (his head; he is dressed in white because you are supposed to not see his body). As a screenshot it doesn't look to impressive: the skill of it is the way the two moved around, with the player bouncing the other chaps head realistically. Another very good one was of a snooker table, where ten people had coloured their heads and then bounced around when struck by the white ball. The contestants make all their props, and jumped around happily when their clapometer scores went up... someone should take it up over here. I didn't have much luck finding it on the web: the closest I found was this pdf (which also features "I’M OLD ENOUGH!": Very small kids are sent out by their parents to go shopping alone for the first time ever. Is that real? Could you do that over here?).

2006-01-16

Lovelock: We're all going to die!

Well, if I must be called alarmist I may as well justify it :-)). The source (thanks CH) is James Lovelock in the Independent, who doesn't use those exact words but does say:

My Gaia theory sees the Earth behaving as if it were alive, and clearly anything alive can enjoy good health, or suffer disease... The climate centres around the world, which are the equivalent of the pathology lab of a hospital, have reported the Earth's physical condition, and the climate specialists see it as seriously ill, and soon to pass into a morbid fever that may last as long as 100,000 years. I have to tell you, as members of the Earth's family and an intimate part of it, that you and especially civilisation are in grave danger... We are in a fool's climate, accidentally kept cool by smoke, and before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.


Obviously, billions of people *will* die before the end of the century; I will probably be one of them to die of old age. As long as I don't fall of a mountain or some other accident. Will I die of climate change? At the moment it seems unlikely to me. He also says:

Unfortunately our nation [the UK] is now so urbanised as to be like a large city and we have only a small acreage of agriculture and forestry. We are dependent on the trading world for sustenance; climate change will deny us regular supplies of food and fuel from overseas.


We *are* quite urbanised, but the farming area is still much larger than the urban area.

Anyway, enough knockabout, what about the substance of Lovelocks words? I disagree with the *certainty* he uses. The temperature rises are not certain; they depend on future CO2 etc emissions (if he is trying to say that these are already committed due to existing forcing, then he is way off the mark; but its all so broad-brush its rather hard to tell). This applies to the "impacts" bit too: i.e. the billions-will-die. He may be right; he may be not. He certainly doesn't back it up with any evidence. Apart from his reputation, why should anyone believe him? Also, his the climate specialists see it as seriously ill, and soon to pass into a morbid fever that may last as long as 100,000 years misrepresents what the "climate specialists" do (if he means the physical climatologists): which is to say, we may well predict (or project) temperature rises, but... tend to leave the impacts alone. And of course the we're-all-going-to-die stuff plays into the hands of the septics: if its going to happen anyway, well then why bother do anything. Lovelock doesn't quite say this, or perhaps he says it then unsays it I cannot see the United States or the emerging economies of China and India cutting back in time... which if read carefully does make it clear that all this *is* contingent on future emissions.

His temperature predictions are:

...as the century progresses, the temperature will rise 8 degrees centigrade in temperate regions and 5 degrees in the tropics.


and thats about all the substance (apart from noticing the recent global dimming; perhaps he has got carried away with that?) (He also sez We have given Gaia a fever and soon her condition will worsen to a state like a coma. She has been there before and recovered, but it took more than 100,000 years - what is the 100kyr a reference to? One stoat-point to the first convincing answer). Now we all know (having read James "Pielke Demolisher" Annan) that high values of climate sensitivity are unlikely. And the IPCC range is something like 1.5-5 oC (e.g. here). However, what I wanted to hang on this is the fact that temperature increases are expected to vary very strongly by region, and in particular the continents warm rather more than the seas. So its quite possible to get 5-6 oC increases even from the multi-model mean (e.g. this, which is admittedly the TAR but I don't think the numbers are bigger now). But I'm not sure where the 8 oC in the temperature regions and 5 oC in the tropics comes from - perhaps some particular model?

is it possible that all this is explained by My new book The Revenge of Gaia expands these thoughts...? I hope not. All in all I'm inclined to file this under "irresponsible journalism".

Wikinews

A few snippets from wikipedia... I'm now an admin, and hence have ultimate power to CRUSH ALL MY ENEMIES HA HA HA HA!!! <evil laugh trails off into the distance>. Sadly no: the rules prohibit me from abusing my powers and there are always other people watching anyway. And not that I have too many enemies, Of Course. Some of the comments are interesting though: try the RFA, scroll down for the Opposes.

And I've just made my 10,000th edit. That slacker Lubos only has 2.3k, & Charles matthews has a feeble 54k.

Blogroll update &c

A boring post pointing out that I've mildly updated my blogroll (its those cryptic letters at the top...). Now the second line is non-climate blogs; or things I don't read so often. Or something.

Also (hint to JF...) Deltoid has now moved to Seed/Scienceblogs; as has Chris Mooney; and as will I, at some point, I think/hope.

2006-01-12

Plants and Methane

There is an interesting paper out in Nature today (don't send me it, I've just discovered we have Nature online from work, how nice; if you too have access, the article is here and the commentaries here and here: so I've downloaded the pdfs into my computer but not yet into my brain). In the meantime I will of course recomment to you the RealClimate take: Scientists Baffled. I will strongly disrecommend the Grauniad's stupid Global warming: blame the forests; the BBC's Plants revealed as methane source is a bit better.

The point being that this (if true) is a change to the methane source (by up to 30%) but CO2 is a bigger forcing that the total methane; and of course the total methane levels in the atmosphere remain what they have always been measured to be, so historical forcing estimates from total methane remain unchanged. Perhaps the attribution will change a little bit: though to first order we have lost forest over the last century I think, so if plants are a net source that means we've been losing plant sources which means (given that we know the absolute levels) that anthro methane sources have grown more than previously believed...

2006-01-11

Blair and Hobbes

I'm a bit of a fan of Hobbes (I love the language in [[Leviathan]]; its like the King James bible. The book itself is a great read, and a wonderful source of ideas and argument. But... would you want to live in a society where, for example it is annexed to the sovereignty to be judge of what opinions and doctrines are averse, and what conducing to peace; and consequently, on what occasions, how far, and what men are to be trusted withal in speaking to multitudes of people; and who shall examine the doctrines of all books before they be published?).

I had (independently of many others, I'm sure) the idea that US (foreign) policy is based on Hobbes-type ideas (this briefly mentions the same; I assume its a commonplace). And now Blur is citing him... or so sez the Grauniad: when I read "PM cites Hobbes and Tawney to justify new police powers" I was agog. Which bit does he quote? there can happen no breach of covenant on the part of the sovereign; and consequently none of his subjects, by any pretence of forfeiture, can be freed from his subjection perhaps?

But with characteristic newspaper distain for sourcing, all the paper says is Quoting the 17th-century political thinker Thomas Hobbes and 20th-century social critic RH Tawney, the prime minister hoped the Respect action plan launched yesterday would not be judged on whether or not it was "tough" or populist but as opening a "genuine intellectual debate about the nature of liberty in a modern developed society". Hmmm, I suspect Hobbes would not have been very impressed by a Sovereign with a Respect Action Plan. The Civil Sword was more in his line.

So I'm forced off to the #10 website to find the speech. And Prez Blur sez: More grandly, it is the answer to the most fundamental question of all in politics which is: how do we live together? From the theorists of the Roman state to its fullest expression in Hobbes's Leviathan, the central question of political theory was just this: how do we ensure order? And what are the respective roles of individuals, communities and the state? And thats the only use of Hobbes I can find. So: Blur is *not* quoting Hobbes, only citing him: or rather, invoking H's mighty name in an effort to lend weight to B's pallid policies.

And does he seriously believe that politicial theory attained its fullest expression in Hobbes's Leviathan? Its bizarre. Yes I love the book and the language but you can't use it as a textbook for running a state (I'm sure Blur would love to, but even our supine parliament wouldn't let him go that far).

2006-01-09

Your blog seems to be corrupted a little bit...

Not, not the content, the format. IJ points out that viewed with Internet Exploiter the sidebar on the right drops down to the bottom. Indeed it does, though if you look closely you'll see it puts it in the correct place to start with, then reformats the sidebar to the bottom later. Odd.

I've fiddled with the page width to see if that helps, but it doesn't, so for the moment: my apologies to IE folks, and perhaps you need to upgrade to Firefox :-). If anyone understands CSS and/or IE, please take a look at the page source and tell me whats wrong...

2006-01-05

Poor headlines: meat and CO2

I read this in the paper Grauniad; but Chris Mooney provides an on-line link. CM doesn't commit himself to an opinion on it, but I will: its poor, at least in terms of headlines. Read New research indicates that gas-guzzling cars are a much less important factor in climate change than the huge amounts of food devoured by carnivorous 'burger man' (or even Meat Eating Causes Global Warming, ahem) and you get the impression that... meat eating causes GW. But the bottom-line factoid of the story is An average burger man (that is, not the outsize variety) emits the equivalent of 1.5 tonnes more CO2 every year than the standard vegan. By comparison, were you to trade in your conventional gas-guzzler for a state of the art Prius hybrid, your CO2 savings would amount to little more than one tonne per year. This probably tells you more about the smallness of the savings from a Prius. Average annual CO2 emissions are something like 10t most of which is fossil fuels not food, so however you look at it diet isn't the *major* cause. However, even though the article sez "Stop eating meat" is unlikely to be the favourite slogan of the new Stop Climate Chaos coalition. Even "eat less meat" might not go down too well... I'm not sure why it does (disclaimer: I'm a vegetarian, but not a vegan). The UK is struggling to emit less CO2. If we could save 10% just by a minor change in diet, why not...



[All this vaguely relates to an earlier post of mine, GW, methane and vegetarianism: http://www.earthsave.org/globalwarming.htm]

Aerosols again

Having just said that not much is happening in the climate world, there was an interesting paper in Nature just before Christmas in Nature: Bellouin et al., about possible underestimates of the aerosol effect. Oddly enough I haven't heard much about this... maybe its because it was just before Crimbo (someone has just posted it to sci.env though). Or maybe its because no-one wants to talk about it: from the Grauniad: "We found that aerosols actually have twice the cooling effect we thought," said Nicolas Bellouin, a climate modeller at the Met Office. The consequence is that as air quality improves and aerosol levels drop, future warming may be greater than we currently think.". Thats not really anything the skeptics are going to want to tell you. And if you're a... opposite-of-skeptic I suppose, then the idea that the GCMs have got the aerosol forcing wrong is nothing to trumpet either.

I did read the Nature article and I remember thinking it seemed Fair Enough (though I can't re-read it because the evil information-hoarding folk at Nature won't share it... I can't even find a free abstract); you can read the UKMO press release. There was some kind of let-out clause (that maybe, to compensate, the *indirect* effect could be weaker).

Someone over at wiki got round to asking someone at NCAR, who said:

The exact magnitude of various forcings is uncertain. The new estimates you refer to for aerosols are larger than what some models use (the magnitude of what models compute, for example, for sulfate aerosols varies depending on the nature of their sulfur cycle models or types of sulfate aerosol concentrations they use) but not out of the range of uncertainty for aerosol forcing used across all of the more than 20 models currently being assessed in the IPCC AR4. This accounts for some of the range of model responses to the simulation of 20th century climate. Even with this uncertainty in aerosols, the GHGs are still the largest forcing by far, and are the big driver for late 20th century warming and estimates of 21st century warming. The latest simulations will be assessed in the IPCC AR4, but many modeling groups are publishing their latest findings in the peer reviewed literature now (for example, from our group see: Meehl et al., 2005: How much more warming and sea level rise? Science, 307, 1769—1772). [1]


so its possible that another answer is as she says: the new numbers may be different to previous UKMO ones but are within the uncertainty range.

[Update: the pdf fairy has been to visit, so I've read it again (or rather, for the first time: I now realise I only read the commentary; reading the paper I don't see the bit about indirect effect, so maybe that was invented by the commentary...). They estimate a (clear sky) RF of -1.9 W/m2 whereas the TAR (graph estimates about -0.4, with a range up to nearly -1.0. Though the TAR value isn't clear-sky... but B et al. say the model value is -0.5 - -0.9, which is similar.

Anyway, here is the abstract:

Atmospheric aerosols cause scattering and absorption of incom­
ing solar radiation. Additional anthropogenic aerosols released
into the atmosphere thus exert a direct radiative forcing on the
climate system 1 . The degree of present­day aerosol forcing is
estimated from global models that incorporate a representation
of the aerosol cycles 1--3 . Although the models are compared and
validated against observations, these estimates remain uncertain.
Previous satellite measurements of the direct effect of aerosols
contained limited information about aerosol type, and were
confined to oceans only 4,5 . Here we use state­of­the­art satellite­
based measurements of aerosols 6--8 and surface wind speed 9 to
estimate the clear­sky direct radiative forcing for 2002, incorpo­
rating measurements over land and ocean. We use a Monte Carlo
approach to account for uncertainties in aerosol measurements
and in the algorithm used. Probability density functions obtained
for the direct radiative forcing at the top of the atmosphere give a
clear­sky, global, annual average of 21.9 Wm 22 with standard
deviation, 60.3 Wm 22 . These results suggest that present­day
direct radiative forcing is stronger than present model estimates,
implying future atmospheric warming greater than is presently
predicted, as aerosol emissions continue to decline


I'm sure Nature won't mind that.]

Wiki: Cold Fusion

Since the wiki climate pages have been pretty sane recently, and not a lot has been happening on the climate front, I've been browsing further afield and contributed to the [[Cold Fusion]] page. Or rather, to the discussion of it. Its interesting in itself, if you're interested (so to speak) but its also interesting as an illustration of the problems of psuedo/fringe science: that the True Believers in such are generally far more commited, and often more knowledgeable (in some sense; they know more things about it but not the one key thing: that its wrong...) that the larger mass of folk.

So if anyone out there has a reasonable knowledge of nuke-related matters (hello, John!) do go and have a look and leave a comment at least.

And while I'm on this stuff, I really ought to mention the RFA against Reddi.

2006-01-03

Nuclear CO2

A while ago I posted tangenitally on the CO2 output from Nukes here. Now a new study (whose reliability I have no way of assessing) says:

The nuclear process emits 2-6 grams of carbon equivalent per kilowatt-hour, while coal, oil and natural gas emit 100-360 grams of carbon per kilowatt-hour [1].


(actually thats The Age's paraphrase; hopefully they can report figures accurately).

After my last post, an anonymomous commenter pointed me to the opendemocracy posting which asserts that:

A complete life-cycle analysis shows that generating electricity from nuclear power emits 20-40% of the carbon dioxide per kiloWatt hour (kWh) of a gas-fired system when the whole system is taken into account.


Hmm... how do we reconcile these two estimates? Firstly gas is better than oil or coal so perhaps we can take the "100" from the first; but even then taking the "6" from the first and the lowest, 20%, from the second we have 6% compared to 20%, a factor of 3 disparity. Unfortunately the source for the second lot (http://www.oprit.rug.nl/deenen/) is currently offline.

Based on a simple argument (I think most of the monetary costs of nukes is engineering and safety and disposal; if the CO2 costs were really 40% nukes would probably be even more uneconomic than they are) I'm disinclined to believe the second set. That doesn't mean I do believe the first, though.

I do agree with SB on the comments to my first post: that there are vast energy efficiency gains possible. BS's argument that nukes are too safe is worth reading too. But having said that, any other refs to nukes CO2 would be welcome.

Oh... and this *isn't* going to become an energy-sources blog... back to the science soon!

2006-01-02

Gas excitement

Happy New Year folks. Peace and Good Will to all people. Now read on...

Gas delivery is in the news here, not a usual topic even in winter. But the shut-off by Russia of the Ukraines gas supply is having interesting consequences. So far they are only interesting, hopefully they won't get worrying. Refs for this: Guardian and again and more; and the BBC.

The story so far... the EU imports 40% of its gas; the UK, 10%, since the North Sea is starting to run out. Russia exports a lot, but recently decided that the Ukraine ought to pay full market price instead of being subsidised (which is sort-of a pay-off for them cosying up to Nato and the EU and stuff; though exactly why the Ukraine should be subsidised I'm not sure; anyway, thats all the politics bit). Ukraine refused, Russia turned off the taps (in some sense). The complicating bit is that a lot of EU gas goes via Ukraines pipelines; the Russians (in absolutely direct terms) have accused the Ukrainians of diverting some of this and stealing it. Meanwhile the Ukraine accused Russia of resorting to "blackmail" in order to undermine Ukraine's economy.

Now France, Italy, Germany and Poland have reported shortages because of Russias actions and are understandably p*ss*d off; its not clear whether the Russian text is designed to divert blame. The EU have called on Russia and the Ukraine to resume discussions; the US seems to be leaning on Russia a bit.

None of this has much to do with climate or science, of course. But it does give some taste of the unpleasantness that might happen when gas supplies really start to run out. It may also affect the should-we-build-more-nukes debate. No-one wants to be left cold in the winter.