Bishop Hill Revkin does low climate sensitivity
Feb 4, 2013 Andy Revkin has taken a long hard look at the trend towards low climate sensitivity estimates and seems to conclude that things are just as the sceptics have said.
I can understand why some climate campaigners, writers and scientists don’t want to focus on any science hinting that there might be a bit more time to make this profound energy transition. (There’s also reluctance, I’m sure, because the recent work is trending toward the published low sensitivity findings from a decade ago from climate scientists best known for their relationships with libertarian groups.)
Nonetheless, the science is what the science is.
It's a must-read.
Bishop Hill
Anthony has further insights, gleaned from an email exchange Revkin had with Gavin Schmidt of NASA. Schmidt's view is this:
Andy, I think you may be slightly misrepresenting where the ‘consensus’ on this issue has been. While there have been occasional papers that have shown a large tail, and some arguments that this is stubborn – particular from constraints based on the modern tranisent changes – there has always been substantial evidence to rule these out. Even going back to the 2-11deg C range found in the initial cpdn results in 2005, many people said immediately that the high end was untenable (for instance).
Indeed, the consensus statements in the IPCC reports have remained within the 1.5 – 4.5 range first set by Charney in 1979. James’ work has helped improve the quantifications of the paleo constraints (particular for the LGM), but these have been supported by work from Lorius et al (1991), Kohler et al (2010), etc. and therefore are not particularly radical.
By not reflecting that, you are implying that the wishful thinking of people like Ridley and Lindzen for a climate sensitivity of around 1 deg C is tenable. It is not, and James’ statement was simply alluding to that. For reference, James stated that his favored number was around 2.5 deg C, Jim Hansen in a recent letter to the WSJ quote 2.5-3.5 (based on the recent Palaeosens paper), and for what it’s worth the CMIP5 GISS models have sensitivities of 2.4 to 2.7 deg C. None of this is out of the mainstream.
Lindzen has of course argued for sensitivity around 1deg;C, but Ridley was arguing for 1.6 in his WSJ essay. The idea that figures like this are "untenable" seems to me to be extraordinary given that our only fully empirical estimate and a series of other studies give precisely this figure.
To Schmidt's comment, Revkin adds this:
In policy circles, including popular calculations of emissions trajectories necessary to avoid a high chance of exceeding 2 degrees C. of warming, the hot tail has not been trimmed (unless I’m missing something?).
To me, that says the climate science community — including the Intergovernmental Panel on Climate Change science working group — has not adequately conveyed the reality you state here.
And Richard Betts agrees:
You’re right – see, for example, the Stern Review, Table 1.1 right-hand column, citing Meinshausen (2006) to give a wide range of warming for different stabilisation levels, and compare that with the other 2 columns (TAR range and Hadley Centre model range) – the Meinshausen range was then used later in the review to inform the economic impacts modelling (Box 8.1, page 220)
So Stern used a fat-tail distribution not the TAR distribution.
Bishop Hill
I'm struggling to reconcile Richard Betts' observations with the remarks on climate sensitivity by Chris Hope on the PAGE2002 model (the basis of the Stern Review) as reported in my post on Climate Sensitivity and the Stern Report.
The mean value is unchanged from the default PAGE2002 mean value of 3°C, but the range at the upper end is greater. In PAGE2002, the climate sensitivity was input as a triangular probability distribution, with a minimum value of 1.5°C and a maximum of 5°C.
I'm going to ask Richard and Chris to clarify. Please don't jump to conclusions in the meantime.
Bishop Hill
Gavin tweets:
@Revkin somewhat overstates impacts of changes in CS. It is not too small to be negligible, nor so large to be a nightmare
Reader Comments (147)
Again not the fault of the well funded right wing illuminati obstructing climate science. When is it, one might ask? ;-)
Sounds like people rowing back from a early absolute position of climate doom while rather desperately hopping that people will not remember that they where made in the first place .
Sorry but these guys way over sold 'settled science' and overdid the 'insults and smear approach' to support the cause for past claims to be forgotten nor these insults to be excused .
Meanwhile in reality even the 'less wild ' claims look like fallen on their face as the temperatures still fail to raise despite the increases in CO2.
Interesting to see Connolley's take in this.
The sad thing is that hell will freeze before Revkin will even entertain the possibility that Mother Nature is simply doing what Mother Nature has always done and that humanity's contribution — up or down — is minuscule.
Andy Revkin also discusses 'changes in ocean chemistry', as something to be worried about. This subject is a special interest of mine right now.
I've posted this:
'Hi Andy
I'd be very interested to see the actual observational data representing the 'change in ocean chemistry' you mention.
I'm thinking of something like the ocean chemistry equivalent of GISS or HADCRUTx. A substantial database of regular readings taken at many sites over a substantial period. With enough such readings over a sufficient period of time we should be able to understand our ocean chemistry - and any changes - much better.
Can you or your readers point me to it?
Thanks.'
It'll be interesting to see if it passes moderation.
There's a nice record of ocean chemistry changes here: (NOT)
http://stevengoddard.wordpress.com/2011/02/17/monterey-bay-aquarium-shows-no-change-in-ocean-ph/
And once again there is much handwringing about the "policy message". Not only from bloggers, but the supposed "scientists" themselves. Towhit:
From William Connelley referring to the scientists:
and your own quote:
Interesting take on Gavin's explanation in the updates. I don't think he bought it...
Feb 4, 2013 at 5:32 PM | Sean Houlihane
Gavin is a lapdog. He will not buy it until his lords and masters buy it.
Mike Jackson: "Interesting to see Connolley's take in this." I'm tempted to ask why, but on reflection, why bother? As Connolley (with an e) says, he's willing to shill for Schmidt and Annan.
More amusing is that wikipedia has the following, rather good, description, but it seems to have ended up in the wrong place: "is the philosopher and intellectual (though far more so in the image he has created for himself in the novel's provincial backwater than in reality) who is partly to blame for the revolutionary ideas that fuel the destruction that occurs in the book."
All settled sciences are equal, but some are more settled than others.
Looks like slowly but surely the AGW edifice is breaking apart especially now as the mainstream scientists and newspapers try to get out of it with "lukewarming". See NPR on Polar bears, mainstream IPCC Climate Scientist in Sweden saying its all basically tripe and so on and on ect. Even Google I think is giving up on trying to keep antiAGW stories out of its search engine. Only the AGW diehards will still be around maybe for another year or so. I wonder if any of people responsible for the AGW fraud and keeping the game up at the expense of billions around the world will ever be brought to a Court of Justice (The Hague?)
We told him years ago, but he had not ears to hear. I've long defended Andy's intellectual integrity and curiosity, but the hands over his ears didn't help him. Graciously, his moderation of his blog reflects his curiosity.
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you have to enjoy the sight of His StoatiEness, trying to blame journalists for the fact that climate science is so poorly represented in the media, trying to distance himself as far as he can from Annan, and also trying to blame everything on "wackos" - he is not a great example of what the ancient universities produce as science graduates.
Where did he do his first degree, if he has one?
I wouldn't count 3C as low climate sensitivity. But it's a small step in the right direction, acknowledging that very high values are unlikely. Perhaps the start of a long slow climbdown, which will be accompanied by much goalpost-moving and history-rewriting. Revkin still has no clue, regarding Billy Connolley and Gavin as reliable sources of information.
I think Gavin is misrepresenting Annan's estimate.
Annan's 2.5 deg estimate appears to have been made before including the halt in temperature increase, the reduction of aerosol forcing the increase of black cabon forcing and the discovery of statistics errors in multiple papers.
"Yeah, I should probably have had a tl;dr version, which is that sensitivity is still about 3C.
The discerning reader will already have noted that my previous posts on the matter actually point to a value more likely on the low side of this rather than higher, and were I pressed for a more precise value, 2.5 might have been a better choice even then. But I'd rather be a little conservative than risk being too Pollyanna-ish about it."
http://www.blogger.com/comment.g?blogID=9959776&postID=1573684829816144955
kim - you are too generous. I don't see anything approaching integrity or curiousity from Revkin. IMO putting your hands over your ears and eyes, whilst keeping your mouth fully operational, renders you irrelevant as a journalist. Comments like this reinforce it:
"There’s still plenty of global warming and centuries of coastal retreats in the pipeline, .."
A must read? What for?
[Snip - venting]
Update
To Andy Revkin's credit, my post survived moderation unscathed and has been published .
I await any further replies with interest.
I just read the update from Gavin and, as you might expect, it is fascinating in a Cluedological sense:
It recalls the way that climate scientists and Connolley, Hansen et al have been trying to deny that the consensus back in the 1970s was that the world was about to enter a new ice age.
just checked wiki...seems that His StoatiEness went to Teddy Hall - so either he caught the rugby ball at his interview or was able to identify a "blade" - not, in themselves, signs of great perspicacity but they would let you get into Teddy Hall.
Seems to me that those who are trying to rewrite history in vain and futile attempts to show that they were right all along should draw pause from the existence of the Wayback machine.
They should recall that after the BBC spent a lot of effort in a court case to prevent the details of 28gate becoming public, Maurizio Omnologos found it lying around in a Wayback archive anyway. A terrible warning that your words can come back to haunt you.....
Schmidt may have control of the copy of RC that you see today...but that's no guarantee that it wasn't saved somewhere else when it was new. It's rarely the original offence that gets you ...it's the cover-up.
As the vile Huhne has just discovered.
How could anyone seriously have ever suggested a sensitivity of more than 2C per doubling? Temperatures have barely risen 1.5C since the end of the little ice-age, when CO2 was about 265ppm:
Nik's long slow thaw graph
It is now at 390ppm. 390/265 = 1.47
So 1.47 gives c. 1.5C warming.
therefore a doubling gives 1.5C x 2/1.47 = 2C.
And that is only if we accept that all the warming from the end of the LIA to present was due to CO2 (very unlikely - did the atmospheric concentration of CO2 decrease from the end of the MWP?) Hence natural variability / long term oceanic or solar cycles are significant. My feeling is that climate sensitivity is only about 0.75C at the most. That or negative feedbacks (increased cloud cover and hence lower insolence kick in very quickly and cancel out the alleged increased GHG effect).
Just to be clear, Revkin is a true believer - he and Joe Romm have the same goals. Revkin is simply more of a strategic thinker. Romm speaks only within the echo chamber. Revkin wants to convince the uncommitted middle. Thus, Revkin will carefully backtrack when necessary. And when he does, he always apologizes to his tribe. Note this: "Of course, I may still be exhibiting “reverse tribalism” even by digging in here, but at least I’m stating that up front." Here he's like a Communist party member at a show trial, apologizing for his sins. Reverse tribalism is what they're now calling admitting the truth, in spite of the fact that it makes 'the tribe' look bad. Revkin will always qualify any admission that the consensus orthodoxy may not be correct.
Not banned yet. Your name is the clue. Andy did not ban my comments during 2008, when the bitter ones called his place DotKim. Well, he did take out me calling one of his bitter one's body 'the bag of bones that cages your soul'. Heh, I thought it was pretty tame.
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The marvelous irony, Iapogus, is in thinking where we would be if man were not responsible for the rise in temperature since the LIA. The children would know what snow is, from walking up hill five miles both ways from school. We are blessed if we did it, and blessed if we didn't.
Next year we'll learn just how blessed be we once sensitivity is better circumscribed.
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So kim - a journalist allowing a contrary view is something of note? Surely the null reversed?
Its beginning to look as if Arrhenius (a fellow chemist hem, hem, not a 'climatologist') got the sensitivity about right (1.6-2.1K) in 1907, and it's all been a terrible waste of time, tears, money and MIPS ever since. The results are no more accurate than his.
Perhaps it's because Chemistry is deeply founded in observations, not in theories, while 'Climatology' - and especially climate modelling - is the exact opposite.
Yes, nby, in my sad and long experience a journalist allowing a contrary view on climate is something of note. And I note Andy.
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I took on Eco-alarmer sylvia Tognetti and Eli Rabett (Josh Halpern) with Annan's post here:
http://tallbloke.wordpress.com/2013/02/04/consensus-what-consensus-the-lie-comes-undone/
'Nor so large to be a nightmare'. But you promised, Gavin; where are the Wild Things?
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The bottom line of this is that bigger numbers are scary so are more useful to gain 'political' buy-in even if their not supported by the science. Hence the fact that there finding it hard to drop them altogether but at the same time looking to row back from their early silly claims and say face .
But we been here a few times has with the 'settled science ' idea where they attempt to say they never made any such claim in the first place despite all the evidenced then did . It shows how, once you gone down the 1984 route to 'historic accuracy', its easy to make it a habit that is hard to break.
Surely the alarmists could not fail to be aware that if they always predicted the worst case scenario and kept on exaggerating the threat of global warming, that eventually there would come a day of reckoning. They were knowingly over selling the problem, reality had to intervene eventually, it was inevitable.
Am I reading it right, that Schmidt regards it as a "nightmare" if climate sensitivity turns out to be low?
NW, I read Revkin to mean a high sensitivity would be the nightmare.
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Feb 4, 2013 at 6:27 PM | Latimer Alder
Mr Alder,
Your observations at the above post are so right. The liars will be very publicly exposed by their own lies in their own words - verbatim.
SJ
Dang, NW, that should be Schmidt means a high sensitivity would be the nightmare. But I don't read Gavin so I don't really know what's in his head, besides rowing back catastrophically through Scylla and Charybdis.
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Am I reading it right, that Schmidt regards it as a "nightmare" if climate sensitivity turns out to be low?
For the consensus climate scientist or the antii-fossil fuel eco-green, or the carbon tax by necesity to survive crowd, yes.
To hitch your wagon to the IPCC-derived, Al Gore/David Suzuki narrative requires you to believe that what we are doing will KILL the planet, or at least the human life on it, and do so within one hundred years. You are committed to this horror: so unless you are willing to have your core beliefs and sense of self as a warrior saviour trashed, you will be looking for the signs of impending death, not signs that we will be all right after all.
A strange situation to be in. The probable death of your grandchildren defines your importance in the universe.
No wonder Suzuki holds his wife at night and cries for the fate of humanity (his admission, truly).
The Stern Review did not use a fat-tailed distribution. I used the standard triangular one in PAGE, and add an ad-hoc amount to account for catastrophes.
The impact of a lower climate sensitivity on emission reduction policy is one of three:
If the aim is stabilize concentrations at some level, climate sensitivity is irrelevant (apart from the feedback of climate on vegetation).
If the aim is to stabilize temperature at some level, a lower climate sensitivity implies higher (cost-effective) emissions.
If the aim is to balance the costs of climate change against the costs of emission reduction, a lower climate sensitivity implies higher (Pareto optimal) emissions.
Feb 4, 2013 at 5:15 PM | steveta
From your link:
Good grief! We are truly doomed if governments truly believe this!
That's how I read it too.
Despite these guys' lavishly expressed "love for the planet", the thing that wakes them up in the small hours, tossing & sweating, is the ever growing possibility that the planet's doing fine - but their careers are going down in flames.
'To hitch your wagon to the IPCC-derived, Al Gore/David Suzuki narrative requires you to believe that what we are doing will KILL the planet, or at least the human life on it, and do so within one hundred years. You are committed to this horror: so unless you are willing to have your core beliefs and sense of self as a warrior saviour trashed, you will be looking for the signs of impending death, not signs that we will be all right after all.'
One wheel on my wagon,
And I’m still rolling along
Them Cherokees after me
I’m all in flames, at the reins
But I’m singing a happy song
Are you sure it's his wife?
http://nofrakkingconsensus.com/2013/02/03/david-suzuki-john-abbott-college/
How many of the sensitivity estimations are Not based on simulations (models)?
“What if climate change appears to be just mainly a multi-decadal natural fluctuation? They'll kill us probably.”
Not if you give us our money back.
"Revkin somewhat overstates impacts of changes in CS. It is not too small to be negligible, nor so large to be a nightmare"
Gavin cannot possibly mean what this statement appears to say. It just is not possible. Please someone give me an alternative interpretation, please.
'Gavin cannot possibly mean what this statement appears to say. It just is not possible. Please someone give me an alternative interpretation, please.
It's Gavin Goldilocks and the Three Bears. Not too hot, not too cold..just right,
But the idea that Schmidt ever had locks at all is quite disturbing....Among his many 'challenges', follicular features highly.
Must be a language thing. I see now that Gavin of course refers to CS itself and not the change (towards a lower CS).
Patagon at 8:29
"How many of the sensitivity estimations are Not based on simulations (models)?"
They are easily separated: If the first number is a "1" or "2", they are not by models.
Observations over the last 15 years show empirically that climate sensitivity is about plus 0 degrees.
And you should all feel lucky its not minus 0 degrees!
Yes, pax, that was his confusing ambiguity. He's probably just a little bit cognitively dissonant, and maybe his ears don't want to hear what his mouth says.
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