Bishop Hill RealClimate on Lewis and Curry
Oct 6, 2014 Climate: sensitivity RealClimate has emerged from its latest bout of torpor to publish an article commenting on the recent Lewis and Curry climate sensitivity paper. It's written by Richard Millar, one of Myles Allen's post-docs, and the author seems to have adopted a much more businesslike tone than is normal at RC. Unfortunately, according to the first comment, which comes from Lewis himself, he hasn't got his facts right.
Richard Millar, you write
“They use the latest IPCC numbers for radiative forcing and global temperature changes, but not the latest IPCC ocean heat content data”.
The statement that Lewis and Curry (2014) does not use the latest IPCC ocean heat content data is simply untrue.
Section 3.2 of the paper explicitly states that it uses the climate system energy accumulation observational best estimates and uncertainty ranges shown in Box 3.1, Figure 1 of AR5, which extend to 2011, the final year of all the analyses carried out in the paper. The change in ocean heat content accounts for the bulk of the accumulation. Gregory Johnson is acknowledged in the paper for supplying the underlying data.
The bulk of Millar's case seems to be that the Lewis and Curry estimates are broadly similar to the 5-95% ranges of the IPCC's preferred estimates. However, as Nic points out in his comment, this obscures the fact that the energy budget estimates all have best estimates much nearer the 5% end than the 95% end.
Reader Comments (62)
I love it when the rebuttals come so quickly. Three thousand cheers for Nic Lewis!
I didn't know real climate was still going.
The Climate Establishment seem to be focusing on this 5th percentile range, claiming that recent work that find a reduced mean estimate for climate senstivity still sits within a similar range of likely estimates.
First year statistics students should have had it drummed into them at an early stage, that measure of spread of a distribution, such as variance, or standard deviation give onl the most simplified summary of the distribution of potential outcomes.
A question for Lewis and Curry: what significance if any would the sea ocean energy papers just released (and now written up on Curry's blog) have on the calculations made in your paper? How do those new data and estimates vary frmo the IPCC ocean heat content figures you used and how might htey change wour resullts?
OK, re last post "I didn't know real climate was still going."
Looking down a list of their articles:
Unforced variations: Oct 2014
The story of methane in our climate, in five pie charts
On arguing by analogy
Unforced variations: September 2014
Unforced variations: Aug 2014
Unforced variations: July 2014
Unforced variations: June 2014
I think I can see where they are going wrong.
Sic transit gloria Gavini
I find it amazing it could all be mistaken for science.
Pointman
Amazing how this rebuttal is so easily rebutted by palin and simple facts. A sure sign of panic amongst the warmunists.
And a probable indicator of the quality of a doctorate in climate science these days.
Latin's indispensible at moments like this.
A dictionary too (a not i).
Simon? What a not i?
"The recent Lewis and Curry study of climate sensitivity estimated from the transient surface temperature record is being lauded as something of a game-changer" say RC.
err, is it? Who claimed that? Straw man argument?
omnologos I see your concern. It was an English dictionary I had in mind.
Rud: "...easily rebutted by palin (sic)" So good!
I'd assumed the silence from Real Climate was in hushed but febrile anticipation of Gavin's definitive magnum opus "On Sensitivity Part III": http://www.realclimate.org/index.php/archives/2013/01/on-sensitivity-part-i/comment-page-2/#comment-313424
Realclimate greatest moment was when Jo Abbess (of minor climate fame) suggested the following:
http://www.realclimate.org/?comments_popup=3690#comment-169598
5.I would like to propose that we form a “Phil Jones Devotional Circle”, and put a nice logo on our personal and organisational websites, linking through to a page here at RealClimate (or elsewhere) that extols the virtues of said Phil Jones, and catalogues his many great achievements.
That, at least, could warm Phil Jones’ heart, in letting him know how much we value and support him. If those suffering from septicaemia choose another target, we should have a “We Love…” page for them as well. I think it’s about time we had a page explaining just how much we venerate and adore Michael Mann, for example. And James Hansen. And Malte Meinshausen. And Tom Wigley… There’s such a long list…
Over Easter, I was reflecting on the work of J. S. Bach in his Johannespassion, based on Chapters 18 and 19 of the Gospel of John. So many parallels to the campaign to denigrate, humiliate and crucify Phil Jones…including that immortal, mocking question “What is truth ?”…
We could perhaps entitle our Phil Jones page “Der Jonespassion” ? Or “Stations of the Climate” or somesuch ? Or is that going a tad too far ? - Jo Abbess
-----------------------------
there was a hug a clmat scientist initiative, but know we love you page.... yet
(for the avoidance of doubt, Jo wasn't joking)
Wow, Barry, thanks for that. It matters who we follow, it matters even more who we look to as messiah. I doubt the hard-drinking, mostly impoverished and deeply devout JS Bach would have had such inspiration based on the Climategate emails. But that's the wonderful thing about freedom: you get to choose which messiah, which role model, which wounded hero. All the best with your choices Ms Abbess.
I hadn't seen that before about Jo Abbess, so thank you for that. I suppose if you have a religious name, you're drawn to some sort of religious worship, but this goes so far it disappears over the horizon.
"...the energy budget estimates all have best estimates much nearer the 5% end than the 95% end."
This point is also made about the global temp history, that only 3 out of the 117 models looks like the last 20 years of observation. Yet there is no impact on belief in the models.
It is said that a "longer" term is required to show the general or gross connection between CO2 and temperatures (or other parameters of the changing climate). IMHO this is only true if some of the models allow a step-change from the current style to the future end. I don't see any models that do that.
So, how do you get from here to there? This is a question I have never seen answered wrt temperature, sea level or "extreme" weather. The idea of the warmists is clearly that of of "tipping points", or thresholds, after which an enhanced physics - the large feedback mechanisms, I would suspect - takes place. Models which show this, however, are, to my best knowledge, lacking.
So I would say: answer "How do we get from here to there?" and I will be prepared to be convinced.
Let me give an unfashionable word of approval for Phil Jones who did much good research but obviously tarnished his reputation over climategate.
This from a 2005 paper by Jones and Briffa about the very warm period noted in old records and especially CET;
” The year 1740 is all the more remarkable given the anomalous warmth of the 1730s. This decade was the warmest in three of the long temperature series (CET, De Bilt and Uppsala) until the 1990s occurred. The mildness of the decade is confirmed by the early ice break-up dates for Lake Malaren and Tallinn Harbour. The rapid warming in the CET record from the 1690s to the 1730s and then the extreme cold year of 1740 are examples of the magnitude of natural changes which can potentially be recorded in long series. Consideration of variability in these records from the early 19th century, therefore, may underestimate the range that is possible.”
Phil Jones has written several good books on historic climate and is somewhat more sceptical than some might think. In recent years the Met Office has also moved away from their notion of a steady climate until mans influence from 1900, to one in which natural variability is somewhat more centre stage. The biggest Hockey Stick in the CET series from 1659 (and there are several) is the period noted in the article and not the modern period.
This was an interesting paper – the title is ‘UNUSUAL CLIMATE IN NORTHWEST EUROPE DURING THE PERIOD 1730 TO 1745 BASED ON INSTRUMENTAL AND DOCUMENTARY DATA’. Jones and Biffa. Revised version published 2006.
tonyb
Tony: I really appreciated your input on CET at the meeting at Caroline K's in Bristol with Anthony, Andrew, Nic and co last month. I also appreciate you putting in a justified positive word about Phil Jones here. For what it's worth I think, above and beyond the bad things in the Climategate emails themselves, that the mythology of 'Poor Phil' seeded by Neil Wallis in the PR cleanup of 2010 served not just truth but its subject really badly. That's where this wounded hero motif comes from, picked up in extreme form by Jo Abbess. It doesn't help any of us get near reality, least of all the man himself.
I've always suspected that Phil Jones is a pretty decent bloke who got into bad company and was too polite to resist.
These papers are free-access available online until January 2015 at http://www.annualreviews.org/toc/statistics/1/1:
Statistics and Climate,
Peter Guttorp, Department of Statistics, University of Washington, Seattle, Washington 98195
Abstract
For a statistician, climate is the distribution of weather and other variables that are part of the climate system. This distribution changes over time. This review considers some aspects of climate data, climate model assessment, and uncertainty estimation pertinent to climate issues, focusing mainly on temperatures. Some interesting methodological needs that arise from these issues are also considered.
First paragraph of Introduction:
1. INTRODUCTION
This review contains a statistician’s take on some issues in climate research. The point of view is that of a statistician versed in multidisciplinary research; the review itself is not multidisciplinary. In other words, this review could not reasonably be expected to be publishable in a climate journal. Instead, it contains a point of view on research problems dealing with some climate issues, problems amenable to sophisticated statistical methods and ways of thinking. Often such methods are not current practice in climate science, so great opportunities exist for interested statisticians.
Climate Simulators and Climate Projections,
Jonathan Rougier and Michael Goldstein
Department of Mathematics, University of Bristol, Bristol, BS8 1TW, United Kingdom;
Department of Mathematical Sciences, University of Durham, Durham, DH1 3LE
Abstract
We provide a statistical interpretation of current practice in climate modeling. In this review, we define weather and climate, clarify the relationship between simulator output and simulator climate, distinguish between a climate simulator and a statistical climate model, provide a statistical interpretation of the ubiquitous practice of anomaly correction along with a substantial generalization (the best-parameter approach), and interpret simulator/data comparisons as posterior predictive checking, including a simple adjustment to allow for double counting. We also discuss statistical approaches to simulator tuning, assessing parametric uncertainty, and responding to unrealistic outputs. We finish with a more general discussion of larger themes.
1. INTRODUCTION
Our purpose in this review is to interpret current practice in climate modeling in the light of statistical inferences about past and future weather. In this way, we hope to emphasize the common ground between our two communities and to clarify climate modeling practices that may not, at first sight, seem particularly statistical. From this starting point, we can then suggest some relatively simple enhancements and identify some larger issues. Naturally, we have had to simplify many practices in climate modeling, but not—we hope—to the extent of making them unrecognizable.
Climate: your distribution of weather, represented as a multivariate spatiotemporal process (inherently subjective)
Weather: measurable aspects of the ambient atmosphere, notably temperature, precipitation, and wind speed.
Richard
last year I was at the Met office for a meeting about CET with David Parker, who created the 1772 version, and Kate Willet senior scientist. both very charming and it turns out that Kate was Phil Jones' post grad mentor. She spoke very highly of him.
I would like to meet Phil much more than I would like to meet Dr Mann.Perhaps Dr Betts can facilitate another rapprochement?
Tonyb
tonyb
"Jones and Biffa"
Trivial, but that made me smile, as Biffa is our local waste/recycling company. I wonder if there are Briffa trucks that go round collecting larch logs?
RoyFOMR I am afraid you expect suspect wrong . Jones was one of 'the Teams' main people behind attempts to manipulate journals to toe the team line and keep others out . He planed to avoid FOI's before he even got one and got the university FOI office to do his dirty work for him by bullying and misleading them . And this is guy who said 'why should I share the data with you , you only want to find something wrong with it '
Although he loves to sell himself as a victim when the Team was riding high he was more than happy to be the villain enjoying his ill gotten gains. Unlike Mann he may keep his head down , but he is still very much one of those who put ego and politics before the truth and good science. And attacked any who dare point out how unsettled the science really was. It is just sad that a 'retirement' is probable the worst thing that can happen to him facts to his own poor actions, we can but hope that like the rest of the Team he lives long enough to see his lives work dumped for the junk it is .
PJ criticised the HS publicly, got a call or 200 from the Mann, then sold his soul to the Cause, or maybe just got himself manipulated, earthenware in a shipment of cast irons as an Italian writer would say.
KNR
University of East Anglia refused to share information on global warming
The university at the centre of the 'climategate' scandal behaved in a "reprehensible" manner by refusing to release research behind the science of global warming, according to MPs.
http://www.telegraph.co.uk/earth/environment/climatechange/7538446/University-of-East-Anglia-refused-to-share-information-on-global-warming.html
If you sleep with dogs, you will get fleas. even if they are professors of fiddling and dirty tricks. Too many people here just want to sit at the top table and look important..
Is there any mileage in Robert Way's response to Nic
Perhaps you're right KNR. I was aware of that side of PJ from CG but every dog is entitled to a bite. I've little doubt that he was deeply scarred by the revelations of CG and regrets his time of running with the pack.
As time has revealed he would not have been able to stand up against Mann or the core of the coterie. It takes a Steyn or a Judy or a Steve McIntyre to do that.
His silliness will not be forgotten but, hopefully, it can be forgiven.
One out of work post-doc seeking careful supervision, or possibly a job in politics.
"However, as Nic points out in his comment, this obscures the fact that the energy budget estimates all have best estimates much nearer the 5% end than the 95% end."
This turns out not to be the case. Two recently published papers in Nature Climate Change suggest that the temperature changes (on which the ocean heat budget is based) have been underestimated.
I just want to retract my claws on this and similar issues, somewhat. We have all ended up in situations at work we'd rather not be in.
In my opinion,the climategate E-Mails do not tell you who Phil Jones was, but they do tell
you exactly who he is now.
Sadly, Nic received an abusive comment within an hour of his reply. Typical of the likes of WebHubTelescope, aka Paul Pukite.
Re Phil,
When I renewed a recreational interest in global warming, after a gap from 1994 to 2005, the first email exchange that I started was with Phil and some of his group.
This was because there was a prima facie case of cherry picking in studies of UHI in three countries.
Phil's answers were evasive then. They were anomalously strange compared with scientist-to-scientist exchanges in other sub disciplines of science, under way in the same period.
It was not many months later before I did a Richard Muller choice and added Phil to a group of people with whom I would no longer choose to interact.
Those who are going soft might be excused if they are not hard scientists accustomed to a certain standard of discourse. They can be excused if they are young enough to have never lived in the days before climate researchers elevated intellectual dishonesty to an art form. They can be excused if they imagine that standards are unimportant.
However, there is no excuse for senior, experienced scientists with proud and visible track records to condone, overtly or covertly, the systematic trashing of science conducted by many climate researchers over the past 20 years or so.
It will take another 2 decades to repair the main harm, to allow the general public to see the value that good science adds to society. If cherished personal beliefs in the poor science of global warming have to suffer along the way, too bad. No amount of obfuscation can ultimately overcome fundamental outcomes of good science, when it is allowed to be seen.
The work that Nic is presenting has a quality not apparent in Phil's work. Forget the losers in this business and spend your time with quality scientists and their work.
RichieRich,
I can't speak for Nic Lewis, or how he spends his time. Or who he chooses to respond to. There may be merit in your latest question.
But there may be more mileage in your question if it wasn't posted at RC.
It is possible other people may have relevant technical comments they could make on the matter. But if such comments were supportive of Nic Lewis, I could not trust RC to exercise any reasonable degree of impartiality. The probability that "incorrect" opinions would be deleted at RC discourages me from even bothering to click on your link.
I know they are not quite as bad as you-know-who, and are far more techically competent, but their high-handed intolerance of dissenting views means that they are tarred with the same brush.
Entropic man:
"Two recently published papers in Nature Climate Change suggest that the temperature changes (on which the ocean heat budget is based) have been underestimated."
First, and most importantly, the observational estimate for TCR -- which is the relevant metric for prediction of temperature over say, 50 to 100 years -- does not depend on ocean heat uptake. Thus, Lewis&Curry's best estimate of 1.33 K is unaffected, even if the Durack et al. paper is correct.
On the other hand, the estimate of the (less relevant) ECS is affected by ocean heat uptake. While a proper recalculation would require some work from me to modify the values in their software and re-run it, one can make a reasonable stab at the effect by noting that the denominator in the ECS estimate is ΔF-ΔQ; for Lewis&Curry's best comparison (1859-1882 vs. 1995-2011) the mean ΔF is 1.98 Wm-2 and the mean ΔQ is 0.36 Wm-2. [From their Table 3.] From the summary at Judith Curry's blog, "This would imply that the that during the period from 1970 to 2000 the Earth was absorbing between 0.04–0.13 Wm-2 more than previously estimated, they [Durack et al.] say." So the mean denominator changes from 1.98-0.36 = 1.62 to a value 0.085 less; this is about a 5% reduction and would thus entail approximately a 5% increase in the ECS estimate. So the median value of 1.64 K/doubling becomes 1.72 K/doubling. There is some effect upon ECS, but hardly a huge change.
@ Bob Tisdale | Oct 7, 2014 at 12:43 AM
You're not wrong. That said, the way Nic closed his reply i.e.
doesn't strike me as overly conciliatory and I can see why it might have prompted the response it did from Robert Way.
Do my eyes deceive me - Nic is starting to talk about modes (best estimates) rather than his preferred median (midrange)? Well better late than never.
However this shows how it is impossible to meet these zealots halfway. Nic uses the official IPCC data and the official IPCC-touted method even though both of them smell like week-old fish and then he is told that he didn't use the latest even fishier upwards adjustments (some of which were even unpublished) and the originator of the 'method' says they don't now think it's any good at all. But hey never mind the quality [of the data], feel the width (5%-95%)! Gavin is the originator of much truthiness and the backwards idea that an increasing error band somehow makes estimates better rather than blindingly obviously worse has been slavishly copied by the headless chickens that seem to dominate climate communications.
Having looked at some of Phil's comments on http://wattsupwiththat.com/2012/01/06/250-plus-noteworthy-climategate-2-0-emails/, I agree that PJ is a complex character. However, I am with Geoff [Oct 7, 2014 at 12:58 AM] and find it difficult to give Phil the benefit of doubt. Under his leadership, CRU has lost raw data, adjusted data, fudged data, mislead decision-makers and the media, and broken UK data protection law.
Paul Pukite is one of the ever-dwindling climate clique who still think there has been no hiatus/pause/plateau/peak despite the cause for the pause being the current climate hot topic. Such a blinkered outlier criticising anyone else's work is beyond parody.
Robert Way has shown hiimself on SkS to be a person who knows that much of the climate field is not only wrong but wrong-headed:
http://climateaudit.org/2013/11/20/behind-the-sks-curtain/
yet seemingly he doesn't really care because both the luddite underlying message and (more importantly) his own career is far more important than mere truth. Why would anyone then care about his minor contribution in the field of creating data out of thin air, which was originally touted by the press with a headline and corresponding trendline totally unsupported by the actual paper? In fact using Best (imo Worst as it doesn't reconcile satellite data) makes absolutely no sodding difference to the shaky notion of climate sensitivity based on biased, pessimistic guesswork - which by the way is still only an upper bound; the accepted lower bound being a no-feedback 1K.
"...I can see why it might have prompted the response it did from Robert Way."
Robert Way thinks Lewis should have used Robert Way's paper and gets upset that he won't. No surprises there.
Talking about the confidence intervals instead of the medians as though they meant were the same thing is the latest virus to spread among the brain-dead climate activists. It's one thing to say high values for sensitivity (or any estimated risk parameter for that matter) should not be ignored in favour of lower values. It is a different thing to adopt a probabilistic approach using available data to actually calculate sensitivity. The former is appropriate in 'deep uncertainty' - per Judith Curry's approach, whereas the latter is to take a deterministic, physical approach. Now the climate community, including the activists have been hell-bent on insisting that our understanding of the climate system based on known physics is complete.
Treating 5th and 95th percentile estimates the same as the median implies the activists think there is deep uncertainty about what future sensitivity is likely to be. Who believes this to be true? We can go so far as to say climate activists forfeited the right to any sane risk estimation approach with their cries of 'the science is settled'. When the best estimate was 3C and the upper end was 4.5C, all one could hear was how settled everything was. Why perform data analyses and calculate probabilities when all that's is required is high enough an upper bound and paleoclimate estimates have given all that is needed?
Geoff Sherrington: For me your history is more interesting than that of Phil Jones. Thank you for caring about good science all these years.
I didn't know real climate was still going.
Oct 6, 2014 at 2:32 PM | mike Haseler
===================================
It is indeed, Mike. Nowhere, fast :-)
RichieRich
Robert Way conveniently quotes only part of the final paragraph of my response to his taunting at Climate Audit about not using the Cowtan & Way GMST estimate based on infilled temperature data, or the BEST GMST record. The main parts of my response, which he omitted, were:
The final sentence was aimed at the use by Cowtan & Way of the Bromwich reconstruction at Byrd in West Antartica, a key location in Antarctica, as if it were the record of a single weather station with no moves or instrumentation etc changes. In fact, it is a stitching together without any homogenisation of two quite different stations whose records are separated in time by the best part of a decade.
Harold W
Thank you. Nice to see quantitative discussion.
I always remember being told as a student that proper science is done with numbers.
It also put a lot of the hot air from both sides (including some of my own :-\ )nto perspective. Lewis and Curry have proposed TCR and ECS figures well within the uncertainty range that IPCC derived from the ensemble of papers on the subject. Why are llukewarmers getting hot under the collar about them?
|Nic Lewis Oct 7, 2014 at 2:39 PM
Nic
Many thanks for taking the time to clarify. Very helpful and much appreciated.
Ironic to see somebody comment about the importance of quantitative science and then display an absolute ignorance wrt quantities in climate science.
Entropic man -
Regarding hot air from both sides...there was some umbrage taken in the "Dinner" thread a few days ago, at Rose's observation that views on TCR are not hugely at variance. Taking a single value for convenience (but understanding that any such estimate is necessarily imprecise), AR5 WG1 suggest 1.8 K, while Lewis&Curry suggest 1.33 K, or 3/4 as much. [It makes more sense to consider the ratio, than the difference.] Most of the objections, I think, were from non-lukewarmers, who claim zero or minimal temperature sensitivity to CO2. My comment on that thread gave an estimate of expected warming rate as ~0.1 K/decade, which I think would be the perspective of most lukewarmers.
Much of the hot air(!) on the warmer side of the aisle lies with taking the upper end of the range of sensitivity, combined with the highest emission scenario RCP8.5. Such projections are often conveyed as the result of "business as usual", or provided with only minimal caveats.
Harold W -
The average TCR of the 38 CMIP5 models used for the RCP8.5 runs appears to be close to 1.9 K, rather than 1.8 K. And, as set out in the Lewis and Crok Report on climate sensitivity in AR5, 'A sensitive matter', published by the GWPF, the warming projected over this century by CMIP5 models appears on average to be consistent with a TCR about 10% higher than actual model TCRs, for various reasons. The projected warming per the CMIP5 ensemble mean is about 70% higher than using a TCR of 1.33 K and an allowance for emerging warming in the pipeline.