climate science
stoat | November 5, 2007A point I had forgotten about the recent Canadell et al paper, which mt's recent post reminds me of: as he quotes (scroll down to the update):
Ceci suggèrerait d'après eux que les feedbacks carbone/climat se produisent plus rapidement que notre compréhension des phénomènes gouvernant l'absorption des puits ne le laissait penser.
This is indeed what C et al say, and its one possible interpretation. Another, of course, is that since obs show the airbourne fraction going up, and the models say that they should be going down, then... the models are wrong.
stoat | November 3, 2007OK, the Knight et al. paper is here, thanks folks. Clearly they have had some jolly fun dividing the runs up into trees, but the paper is a disappointment to me, as it doesn't really deal with the main issue, which is the physical plausibility of some of the runs. It *does* talk about "Our findings reinforce the fact that variation of parameters within plausible bounds may have a substantial systematic effect..." but that rather slides over the fact that varying a parameter within a plausible range is *not* the same thing as producing a model with a viable climate. As I reported ages ago, and…
stoat | November 2, 2007OK, so I missed it, not that I was looking for it. Why did everyone else miss it? Because cp.net is obsolete? Since I don't have a subs to PNAS I can't read it except the abstract.
Here is the abstract so you don't have to follow the link and I show up on google:
In complex spatial models, as used to predict the climate response to greenhouse gas emissions, parameter variation within plausible bounds has major effects on model behavior of interest. Here, we present an unprecedentedly large ensemble of >57,000 climate model runs in which 10 parameters, initial conditions, hardware, and…
stoat | October 26, 2007There is a paper by Roe and Baker out in Nature Science arguing that Both models and observations yield broad probability distributions for long-term increases in global mean temperature expected from the doubling of atmospheric carbon dioxide, with small but finite probabilities of very large increases. We show that the shape of these probability distributions is an inevitable and general consequence of the nature of the climate system. Predictably enough it will get misinterpreted, and indeed Nature itself leads the field in doing so. See-also Grauniad.
For a general take, you'll want to…
stoat | October 23, 2007AF (ie, Airbo(u)rne Fraction, ie the proportion of emitted CO2 that stays in the atmos, the rest being sunk in land or ocean) is in the news; I wrote up part of it recently (and detected some nonsense about it a year ago). There is a PNAS paper, Canadell et al; Eli has already done it.
When talking about the N Atlantic results, I was unwise enough to say "But airbourne fraction is still about 55%, so this can't be happening globally." This was in the context of the North Atlantic halving its uptake, which I instinctively thought couldn't happen globally or it would be obvious in the CO2 data…
stoat | October 22, 2007An old line from Steve Bell, BM of course being Margaret Thatcher (as I recall, this was in the context of "batting for Britain" and Mark Thatcher). Ahem. Anyway. Thatcher, of course, as the destroyer of our coal industry in favour of the dash-for-gas, is responsible for any faint hopes that the UK has of meeting its Kyoto targets, so is an appropriate patron for this post.
What brings this on is "Climate change and trace gases" (Phil. Trans. R. Soc. A (2007) 365, 1925-1954 doi:10.1098/rsta.2007.2052 Published online 18 May 2007) where Hansen goes wild with whipsaws and other related stuff ("…
stoat | October 21, 2007Via R4 and mt, Scientists fear climate change speed-up as oceans fail to hold greenhouse gases. Its about the North Atlantic, which is absorbing less CO2 over the last 10 years (note that the article, wrongly, says holds half; Slioch, who does a rather good job in the comments, picked that one up).
But airbourne fraction is still about 55%, so this can't be happening globally. [Update: I now consider that to be dubious, it will get re-considered in an upcoming post -W]
stoat | October 17, 2007[Ooh err. DC points out that she may mean 10 oF. Being American, this is possible. Being a scientist, it shouldn't be (but were she being a scientist there should be a unit symbol, so this is probably the newspaper, so this may well be oF). 3% chance of 10 oF is probably plausible, though I'd still be curious as to where she gets it from. The realisation that this is oF not oC makes this post just about pointless, but I'll leave it up anyway :-) -W]
Thats what Judith Curry says the IPCC says (she is trying to counter Lomborg; thanks to CC for pointing out the article). It doesn't look…
stoat | October 13, 2007On with the boring. Disclaimer: this is nit-picking, for the question "is Gore accurate?". On the wider issue, I'm with the judge and with RC: Gore is basically correct. First off, its not really Tuvalua, its vaguer: "that's why the citizens of these Pacific nations have all had to evacuate to New Zealand" is what the judge has him saying (p 26). Which also fits a transcript NJ kindly pointed me to. Just in case we're in any doubt as to the tense Gore is using, the book rather helpfully has a double page spread with large letters for the hard-of-reading (p186-7) saying "Many residents of low…
stoat | September 26, 2007Not a very good title I fear. I'm referring to Lovelock and Rapley propose cure for global warming wherein James "we're all doooomed I tell 'ee" Lovelock and Chris "used-to-be-my-director" Rapley propose a load of floating pipes to haul up nutrient rich water to cause blooms to lock up CO2.
Its rather short on numbers (how many of these things would you need?) or that wave action via a flap valve will do the pumping required (I presume it must, because they can't have got that bit wrong, can they?). A diagram might help. Ah, the BBC has one but I'm still not sure. Maybe I need a video :-).…
stoat | September 26, 2007 Look at my nice picture. It shows a height-latitude zonal mean of (modelled) temperature, a difference of two 20 year means: 2080-2099 minus 2000-2019. This is for the far-future but we'll pretend its a rough proxy for the present day trends, suitably scaled, shall we.
If you're at all familiar with the "lapse rate problem" you see the familiar: that (at least in the tropics) the upper atmosphere gets to warm far more than the surface: up to 5 oC compared to about 2.5. The reverse is true in the arctic, the antarctic is nearly isothermal except for the top which is probably ozone hole…
stoat | September 24, 2007Eli had a note on this, forgetting of course that I had scooped this long ago :-).
Its worth noting that the paper got slightly weaker after review: the published version says
Whatever the cause of the 1age overestimate, our finding suggests that the phase relationship between CO2 and EDC temperature previously inferred for the start of the last deglaciation (lag of CO2 by 800±600 yr) seems to be overestimated.
The submitted said:
Our finding suggests that the phase relationship between CO2 and EDC temperature inferred at the start of the last deglaciation (lag of CO2 by 800±600 yr) is…
stoat | September 17, 2007Inel drags me into the polar bear wars again by quoting the Heartland Institute: "Real-world evidence shows polar bear numbers are increasing rapidly throughout the Arctic". She offers no evidence against this, which is fair enough as they offer no evidence for it past the bare (geddit?) assertion.
So wot is happening to PB numbers? As in, now, not as in, wot might happen in the future.
The top google hit for polar bear numbers is
Nude Scientist (under myth: Climate myths: Polar bear numbers are increasing). They say "There are thought to be between 20,000 and 25,000 polar bears in 19…
stoat | September 15, 2007 A reader writes... why don't I write about the Arctic sea ice? The answer is, what is there to say that others haven't already? Cryosphere today seems to be a good source, from which my graph is taken. Actually there is something to say which others don't seem to, which is "don't get too carried away with one years anomaly". 2007 is exceptional; so was 1995 which wasn't exceeded until 2005.
[Update: oh dear, Ctoday have now corrected themselves: the Ant ice *wasn't* quite a maximum after all: Correction: we had previously reported that there had been a new SH historic maximum ice area.…
stoat | September 12, 2007The title tells you what I'm going to say, doesn't it? Ah well.
Desmogblog seems to have gone hyperbolic: Dr. Robert L. Park, a professor of physics at the University of Maryland, was more blunt about the importance of DSCOVR's data: "Not knowing may kill us." He is on record as stating that sending DSCOVR to L1 is "the most important thing we could be doing in space right now.". And "Project leader Dr. Francisco P. J. Valero, of the Scripps Institution of Oceanography, described the mission as "an urgent necessity"." Weeeell... you would expect the project leader to be in favour of it,…
stoat | September 10, 2007And they don't come more mega than polar bears. There's a new report out, ClimateFeedback has blogged it, so I feel duty bound to snark about it.
Skipping rapidly over the press release (note how the "will" of the title is "could" in the text) we come to the reports themselves. And how nice: there is one on model uncertainty. Which even tells you how the models they used were selected: The proposed selection criterion selects models with less than 20% error in their simulations of present-day September sea ice extent. Its probably fair enough, if not very exciting (if you want to feel…
stoat | September 6, 2007Thanks to Inel for finding this; look there for the links. So Schwartz (yes that Schwartz) said: "The latest report from the Intergovernmental Panel on Climate Change assesses the skill of climate models by their ability to reproduce warming over the twentieth century, but in doing so may give a false sense of their predictive capability". Exactly why they think this gets quite messy but seems to amount to not knowing the aerosol forcing too well; and they go on to link this to AR4 estimates for climate sensitivity.
This reads wrong to me; and Forster et al reply "However, they have…
stoat | September 6, 2007http://www.zerocarbonbritain.org/ says that Britain can eliminate emissions from fossil fuels in 20 years... by halving energy demand and installing massive renewable energy generation. This contradicts my memories of a talk by David MacKay which (I recall) said that no plausible amount of UK renewables could generate 50% (or even that much) of our energy.
Could someone check their and his numbers to save me the trouble, please?
Thursday: it would seem not :-). So I'll make a start. Looking at the ZC stuff (p94) the vast bulk of the power is coming from offshore wind and wave. In fact the…
stoat | September 4, 2007The kerfuffle over my intemperate denunciation of Chris Mooney refers. Check the comments.
As CM observes, "There have now been eight Category 5 Atlantic hurricanes in the past five years (Isabel, Ivan, Emily, Katrina, Rita, Wilma, Dean, Felix); There have been two Atlantic Category 5s so far this year; only three other seasons have had more than one (1960, 1961, 2005); There have been eight Category 5 Atlantic hurricanes so far in the 2000s; no other decade has had so many. The closest runner up is the 1960s with six (Donna, Ethel, Carla, Hattie, Beulah, Camille)."
I dislike the way CM is…
stoat | September 3, 2007"I can't get over these numbers: The 1980s saw three official Category 5 hurricanes. The 1990s saw two. The 2000s, so far, have seen eight..." says Chris Mooney.
But what are these numbers supposed to mean?
Well, Chris doesn't say what they mean, but since he talks about paradigm shifts (!?!) I'm sure we're supposed to be relating these numbers to global warming in some way. And his co-bloggers comments clarify that these numbers *are* supposed to be linked to GW.
But in what way? The world hasn't suddenly got warmer since 2003 (indeed 1998 was warmer than 2003). And (as Chris says) there…