Bishop Hill More Rose reaction
Mar 19, 2013 Climate: Models Climate: Surface A couple more reactions to David Rose's article have appeared.
First up is James Annan, who feels that his views have been misrepresented. Rose quoted Annan as saying this:
James Annan, of Frontier Research For Global Change, a prominent ‘warmist’, recently said high estimates for climate sensitivity now look ‘increasingly untenable’, with the true figure likely to be about half of the IPCC prediction in its last report in 2007.
The quote appears to have been derived from an interview Annan gave Andy Revkin, where he was quoted as follows
T]here have now been several recent papers showing much the same – numerous factors including: the increase in positive forcing (CO2 and the recent work on black carbon), decrease in estimated negative forcing (aerosols), combined with the stubborn refusal of the planet to warm as had been predicted over the last decade, all makes a high climate sensitivity increasingly untenable. A value (slightly) under 2 is certainly looking a whole lot more plausible than anything above 4.5.
I'm guessing that Rose has read this as Annan writing down climate sensitivity from 4.5 to just under 2°C (hence the reference to "about half"). If so it looks like a misunderstanding.
The second, perhaps more amusing response is from Phil Plait ("Bad Astronomer") at Slate. This is quite extraordinary nonsense.
Plait's case is that Rose's article represents "denial of climate change", and his argument appears to rest on a number of pillars. Firstly, he seems to be saying that Rose should have examined ocean rather than surface temperatures. Now the argument that ocean temperatures should be preferred is undoubtedly well-founded, but it is hardly "denial" to use the measure favourted by the IPCC itself. It would be interesting to see how often Phil Plait has made the case in favour of catastrophic global warming based on surface temperatures.
He next misrepresents Rose's argument, suggesting that he doesn't understand what the graph shows:
Now look again at the graph, and note the measured temperatures are still within that band. Sure, it’s at the low end, but even if the temperatures fell outside the band it doesn’t mean “the world isn’t getting warmer” as Rose so incorrectly claims. It just means the temperatures weren’t quite as high as predicted. They are still within the expected range, though, and still running at a high confidence level.
This is very silly, because it's easy enough to see that Rose understands perfectly well that the graph is comparing predictions to outcome. The first words of his article are:
The Mail on Sunday today presents irrefutable evidence that official predictions of global climate warming have been catastrophically flawed.
Plait goes on to show that if, instead of comparing the outcome to the model ensembles that were used in Rose's comparison (CMIP5), you use the some older simulations (CMIP3), spanning a much broader range of possible outcomes, the predictions are still in play. The latter comparison is based on an article at Real Climate, which notes of CMIP3:
The CMIP3 model simulations were an ‘ensemble of opportunity’ and vary substantially among themselves with the forcings imposed, the magnitude of the internal variability and of course, the sensitivity. Thus while they do span a large range of possible situations, the average of these simulations is not ‘truth’.
So old, uncertain predictions are still in play. More up to date, somewhat less uncertain ones are not. And this is meant to be evidence of Rose's "denial"? (As an aside, we should not Plait's failure to criticise RealClimate's discussion of surface rather than ocean temperatures).
There's what looks like some straw-clutching with invocation of La Nina - presumably as we shift into El Nino conditions, the temperature will leap upwards and Rose's arguments will fall apart. Unfortunately, we have been in El Nino conditions for most of the last 12 months and global temperature still seem to have responded.
Finally we have the usual obfuscation about temperature trends:
He also says, “The graph confirms there has been no statistically significant increase in the world’s average temperature since January 1997 – as this newspaper first disclosed last year” which again was wrong last year and just as wrong now.
Which presumably means that Pachauri and Forster are deniers too. Forster's quote was:
‘The fact that global surface temperatures haven’t risen in the last 15 years, combined with good knowledge of the terms changing climate, make the high estimates [of climate sensitivity] unlikely.’
It's an amazing piece and reading it is an educational experience. See it here.
Back in the real world though, we seem to have three of the top UK experts on climate sensitivity - Allen, Forster and Annan - agreeing that the lack of warming in the last 15 years means that climate sensitivity must be lower than previously thought. And no amount of fulminating from Phil Plait is going to change that.
Reader Comments (58)
Nick - you are wrong. "A value [slightly] under 2 is certainly looking a whole lot more plausible than anything over 4.5" is perfectly compatible with estimating the most likely value to be somewhere "slightly under 2" (*).
This might or might not extend to 1.5C, i.e. "about half of the IPCC prediction in its last report in 2007" (**), a prediction that was 3C. As it happens, that's how I intepreted Annan's statement myself, at the time.
Come to think 1.8C would fall even better under both categories (*) and (**). I would go as far as surmising that the vast majority of readers of this blog plus maybe the Bish, would find themselves at difficulty in trying to disagree with a 1.8C sensitivity estimate.
Annan should be thankful for Rose's article as it has allowed to make his (Annan's) original statement much clearer.
OT: Pharos, I didn't know Bishop Hill had a search tool, and after looking everywhere I can think of, I can't locate one.
Is this perhaps some feature not present for all browsers? It would explain why several differents users have tried to work out how to link to messages without success.
omnologos -
I have staked out my claim to sqrt(pi) at Jeff's blog. ;-)
HaroldW - a sensitivity of sqrt(pi) would be an even stronger Message to the Whole of Creation than Ellie Arroway's discovery of the repeating pattern in base-11.
Re: Mar 20, 2013 at 10:48 AM | steveta_uk
Steveta, Look under 'Navigation' and expand "Navigation tools" - you'll find the 'Search' option there -
and my thanks to Pharos - I too was unable to link directly to a comment - his method of doing so will be really useful.
Omnologos,no it ain't. Something has become a little more plausible than it was,which was very implausible... They're still describing bounds. Rose was making a different 'case' out of that anyway.
The fact that it "was very implausible" might have been implied but am not sure how many people got that nuance in the original by Annan.
Don't know about theoretical sensitivity estimates, but do know from "The Impeccable" observational data set that the 30 year rate of change to date this century is +1.80C/century.
Peaked at +1.99C in 2003, now down to +1.65C, Jan 2013. Where does it go next? Only observational indication at present comes the shorter 10 year trend which turned negative (actual cooling) two years ago and remains negative.
So to achieve +2C this century, never mind by 2050, there is some catching up to do and the direction of the 10 year trend doesn't suggest that the catch up may be imminent.
As always only time will tell what the future holds.