A curiosity from Slingo's paper

Here's something else from Julia Slingo's briefing to central government that caught my eye:

Haven't temperatures been higher in the past? Isn't the hockey stick
graph flawed?
In 2006, the US National Academies of Science carried out a full review of the evidence of past temperature-the so-called 'hockey stick graph'. They found that for the Northern Hemisphere at least, the rapid warming of the past half century has resulted in a level of warmth not seen in at least 500 years, and likely for at least the past 1300 years.

This is rather odd, because the NAS panel concluded nothing of the sort. Slingo appears to have taken the IPCC's conclusions and ascribed them to the NAS.

One could again wonder about whether this represents a partial or impartial view of the science. Can one really brief policymakers on the paleoclimate reconstructions without mentioning the fact that the whole basis of these reconstructions is potentially undermined by the divergence problem?

Comments

[michel]

Here are some more direct quotes. I am afraid that the NAS report simply does not say what Slingo says it does. Here we go. Source is here, read for yourself:-

http://books.nap.edu/openbook.php?record_id=11676&page=5

_____________________________________________________________

Both the number and the quality of the proxy records available for surface temperature reconstructions decrease dramatically moving backward in time. At present fewer than 30 annually resolved proxy time series are available for A.D. 1000; relatively few of these are from the Southern Hemisphere and even fewer are from the tropics (Figure O-2). Although it is true that fewer sites are required for defining long-term (e.g., century-to-century) variations in hemispheric mean temperature than for short-term (e.g., year-to-year) variations, the coarse spatial sampling limits our confidence in hemispheric mean or global mean temperature estimates prior to about A.D. 1600 and makes it difficult to generate meaningful quantitative estimates of global temperature variations prior to about A.D. 900. Moreover, the instrumental record is shorter than some of the features of interest in the preindustrial period, so there are very few statistically independent pieces of information in the instrumental record for calibrating and validating long-term temperature reconstructions.

Despite these limitations, the large, diverse, and coherent collection of evidence represented by the samples shown in Figure O-5 indicates that global surface temperatures were relatively cool between 1500 and 1850 (the Little Ice Age) and have risen substantially from about 1900 to present. The tree-ring-based and multiproxy-based surface temperature reconstructions shown in panel C also suggest that the Northern Hemisphere was relatively warm around A.D. 1000, with at least one reconstruction showing surface temperatures comparable in warmth to the first half of the 20th century. The timing, duration, and amplitude of warm and cold episodes vary from curve to curve, and none of the large-scale surface temperature reconstructions show medieval temperatures as warm as the last few decades of the 20th century.

The instrumentally measured warming of about 0.6°C during the 20th century is also reflected in borehole temperature measurements, the retreat of glaciers, and other observational evidence, and can be simulated with climate models.

Large-scale surface temperature reconstructions yield a generally consistent picture of temperature trends during the preceding millennium, including relatively warm conditions centered around A.D. 1000 (identified by some as the “Medieval Warm Period”) and a relatively cold period (or “Little Ice Age”) centered around 1700. The existence of a Little Ice Age from roughly 1500 to 1850 is supported by a wide variety of evidence including ice cores, tree rings, borehole temperatures, glacier length records, and historical documents. Evidence for regional warmth during medieval times can be found in a diverse but more limited set of records including ice cores, tree rings, marine sediments, and historical sources from Europe and Asia, but the exact timing and duration of warm periods may have varied from region to region, and the magnitude and geographic extent of the warmth are uncertain.

It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries. This statement is justified by the consistency of the evidence from a wide variety of geographically diverse proxies.

Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600. Presently available proxy evidence indicates that temperatures at many, but not all, individual locations were higher during the past 25 years than during any period of comparable length since A.D. 900. The uncertainties associated with reconstructing hemispheric mean or global mean temperatures from these data increase substantially backward in time through this period and are not yet fully quantified.

Very little confidence can be assigned to statements concerning the hemispheric mean or global mean surface temperature prior to about A.D. 900 because of sparse data coverage and because the uncertainties associated with proxy data and the methods used to analyze and combine them are larger than during more recent time periods.

[spartacusisfree]

http://tallbloke.wordpress.com/2012/01/05/i-am-spartacus-stand-up-and-be-counted-for-science/#more-4146

'This morning, I noticed someone had visited and commented on an old thread from last year about the republican vote to defund the IPCC. The comment showed a strong belief in science, and condemnation of the way politics and other non-scientific forces have tried to turn science into a tool of propaganda. What impressed me the most was that this is a person of good standing in the science community, who was prepared to put his full name and list his qualifications and institutional affiliation at the bottom of his comment.'

[Paul Matthews]

One thing set my alarm bells ringing in the covering letter.
Alan Ogden commented on this but unfortunately he put it on the footie thread:

From the covering letter.
'(4) I have asked my staff to prepare a summary document on our recent work with releasing the surface temperature observations and the code, along with showing that the global warming signal is robust. I expect to send that on to you later this week. Hopefully that will be enough to convince Muir Russell not to call in statisticians to repeat the exercise. We would of course be happy to brief him on our findings.'

She could have added 'Statisticians might find something wrong with our work.' :-)

[KnR]

The is statement merely uses science as its 'bitch' to achieve political and finical goals , and anyone that uses such a approach as no role as a scientists, they are however free to sell themselves to sell themselves as PR person or a spinner and so be treated as such .

[Pharos]

Judith Curry has a brand new post up, with considerable relevence to the inherent groupthink risks in the official AGW storyline such as presented in the Slingo briefing.

http://judithcurry.com/2012/01/05/error-cascade/

[jorgekafkazar]

'Latimer and Ian E: Ha, ha! I misread "climatologits" and for a moment understood to be "Climatologititus": '--Justin Ert

And I read the latter as "Calamitologistitis."

[Richard Betts]

Jan 5, 2012 at 12:57 PM | Bishop Hill

I think the NAS summary is much closer to the truth than the IPCC.

WOW!

Putting aside the issue of where "likely" came from (you are right that NAS did not use that word), you actually seem to be accepting the NAS summary, which includes the following:

The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically diverse sites experienced exceptional warmth during the late 20th century than during any other extended period from A.D. 900 onward.
Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium.

See here for source.

Also see Figure S1 here for the NH temperature reconstructions which you say you find "closer to the truth" than those of IPCC

Like I said.... wow....!

:-)

[Shub]

Dr Betts
There are lots of old blog back-and-forths over the word 'plausible'.

Secondly, we *know* exactly how the so-called 'array of evidence' supports (or actually not!) the Mannian hypothesis.

That is exactly where your boss(is she?) is hiding, in all this. I am afraid no reconciliation is possible.

[edward getty]

So. The question is whether Slingo was incompetent or dishonest.

Either way, it does not look good.

I would suggest that it is "very likely" that in this case she was both.

Of course, that tentative conclusion is based on the hockey stick of incompetence and dishonesty exhibited by the IPCC Climastrology Industry in the past two decades.

It is "very likely" that every year since 1998 has been among the worst for climate "science," although that trend has hopefully turned... thanks to blogs like this one.

[mrsean2k]

@Richard Betts

"Closer" != "Close"

It can easily be the more accurate of two vastly-overstated-levels-of-certainty-from-suspect-data without being close to accurate

[Richard Betts]

Hi Shub

My point is, BH seems here to be rather more accepting of the NAS panel's conclusions than appeared to be the case in HSI.

[Green Sand]

Richard Betts,

Slightly OT but pertinent to MO presentation.

I take it you are au fait with the two following “Decadal Forecasts”?

“2009 decadal prediction of global average temperature and validation of past predictions.”
http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/decadal-prediction

and the latest 2011 “Decadal prediction”

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/long-range/decadal-fc

Could you please explain the differences in the two associated charts?

As they are both only related to predictions that started in 1985 as shown in the 2009 prediction, why does the latest chart now start in 1950? It makes it very difficult to assess the changes. One could get the wrong impression.

Why have the historic predictions changed in value between the two charts?

Why does the latest chart include data from Hadley Centre, GISS and NCDC, whilst the prediction is only against Hadley Centre?

Why does the MO not provide the actual data used to produce the charts? Sorry if it is there but I have not found it yet? Whether it is sensible or not people will extrapolate from the charts and that is getting more inaccurate as the latest projections are shown in “thick blue curve”.

This is a request for plain and simple presentation from which maybe, just maybe an understanding and trust may develop. At present this is a very difficult concept, every presentation changes and every change only aids the presentation in one way.

PS, I take it that you are quite happy with the predicted rate of acceleration in mean global temperatures over the next two years?

[Richard Betts]

Jan 6, 2012 at 12:11 AM | mrsean2k

If so, why bother making a big thing of it?!

[woodentop]

@Richard Betts

Richard, the NAS report inconsistencies were noted by no less than Zorita over at CA at the time:

Steve,

in my opinion the Panel adopted the most critical position to MBH nowadays possible. I agree with you that it is in many parts ambivalent and some parts are inconsistent with others. It would have been unrealistic to expect a report with a summary stating that MBH98 and MBH99 were wrong (and therefore the IPC TAR had serious problems) when the Fourth report is in the making.

I was indeed surprised by the extensive and deep criticism of the MBH methodology in Chapters 9 and 11 .

eduardo

http://climateaudit.org/2006/06/22/nas-panel-report/#comment-53380

[MikeA]

Think SteveW might mean sulphur hexafluride.

[Shub]

My point is, BH seems here to be rather more accepting of the NAS panel's conclusions than appeared to be the case in HSI.

I think it would be more accurate to state that there are parts/passages in the NAS report we can all accept, and sceptics do accept. But I am sure, that is strictly more on a literal text-to-text, passage-to-passage basis, rather than taken as a whole. There are several skeptics whose understanding of the issues match precisely, what the scientists at CRU say (only in private of course, in their emails).

Taken as a whole however, I doubt you would find sceptics who would admit that the NAS report's claims are representative of what they think paleoclimatology can confidently lay claim to, especially the tree-ring variety.

[pat]

links to the original nasty piece of work:

5 Jan: PlanetSave: Zachary Shahan: Republican Presidential Candidates Win Climate B.S. of the Year Award
Climate scientists and communicators got together to come up with a list of 2011′s biggest climate B.S.-spewers recently. B.S. standing for Bad Science, of course. Here’s the full list, via Climate Progress:
by Peter Gleick
Fifth Place: Anthony Watts for his BEST, and worst, climate hypocrisy…
Steve McIntyre
And finally, the “dishonorable” mention of the year goes to Steve McIntyre for his despicable smear of climate scientist Dr. Michael Mann of Penn State University (and to Anthony Watts for amplifying that smear) by drawing a parallel between the Penn State pedophilia investigation and their separate scientific investigation of questions about climate research (in which Professor Mann has been completely and repeatedly exonerated). Joe Romm discusses this disgusting case here.
http://planetsave.com/2012/01/05/republican-presidential-candidates-win-climate-b-s-of-the-year-award/

the US obsession with blaming the Right for lack of action on CAGW is hilalrious. Europe is the only horse in the CAGW race right now, yet its Govts are almost entirely rightwing.

would Gleick like to explain why not one memberof Europe's sitting rightwing Govts have even uttered the word "CLIMATEGATE", much less suggested it's all a scam?

18 Nov: Globe & Mail: Map: Europe's shift from leftist to right-wing governments
http://www.theglobeandmail.com/news/world/map-europes-shift-from-leftist-to-right-wing-governments/article2242058/

[AusieDan]

Dr. North was the chairman of the NAS committee.
He was cross examined by the then chairman, Barton of the US Senate House Energy and Commerce Committee hearing on 19th July, 2006:

QUOTE
CHAIRMAN BARTON. I understand that. It looks like my time is expired, so I want to ask one more question.
Dr. North, do you dispute the conclusions or the methodology of Dr. Wegman’s report?
DR. NORTH. No, we don’t. We don’t disagree with their criticism. In fact, pretty much the same thing is said in our report.
UNQUOTE

Dr. Wegman's report had confirmed the findings by McIntyre and McKitrick that Mann's claim that the recent warming was unprecedented in the last 900 years was invalid as it was based on faulty statistical methods.

The NAS report was wishy washy and can be read either way, as was probly the intention.
But North did NOT disagree with Wegman when he was asked the straight question under oath.

[Phillip Bratby]

To those who don't like accusations of lying, here are James Delingpole's latest writing on the subject. (TM James Delingpole)

We're on the lying liars' case. As we saw in Climategate and Climategate 2.0 the Warmist establishment – and that's everyone from the climate "scientists" at the CRU to the IPCC to the Royal Society to the EPA to the entire Obama administration – is so slippery and devious it makes Wormtongue look purer than Sir Galahad. But these days they're so discredited that their bluster, appeals to authority and outright lies just don't seem to work any more. Take this brilliant analysis by Tim Worstall of some unutterable hogwash produced by the Department for Energy and Climate Change (DECC). They're lying. He shows they're lying. Thank you Tim!

[Perry]

In the UK, the Met Office failed to do its job once again.

A spokesman said: “The squally nature of the winds meant that gusts were much stronger than we were expecting.

“Given the impact the winds have caused, had we known, we would have put out a warning across the south.”

http://www.telegraph.co.uk/topics/weather/8995705/Britain-battered-by-hurricane-force-winds-after-forecasters-underestimate-strength-of-gusts.html

[Bishop Hill]

Shub

Indeed. Nobody on this side of the debate is going to disagree with the panel's findings on bristlecones and short-centred principal components.

[Martin A]

Perry Jan 6, 2012 at 7:54 AM

In the UK, the Met Office failed to do its job once again.

A spokesman said: “The squally nature of the winds meant that gusts were much stronger than we were expecting.

“Given the impact the winds have caused, had we known, we would have put out a warning across the south.”

Oh come on. Give the Met Office a break, for heaven's sake.

It was the wrong kind of wind.

[Marion]

It seems the Met Office is little more than a propaganda machine. For example recall the guide they sent out in the run up to Copenhagen in 2009 -

"Warming, Climate Change the Facts" with such alarmist snippets as -

"It is now clear that man-made greenhouse gases are causing climate change. The rate of change began as significant, has become alarming and is simply unsustainable in the long-term"

"Even if global temperatures rise by only 2 degrees Centigrade, 30-30% of species could face extinction"

"Man-made greenhouse gases have altered the balance and are causing climate change"

"Are computer models reliable? - Yes. Computer models are an essential tool in understanding how the climate will respond to changes in greenhouse concentrations, and other external effects, such as solar output and volcanoes."

Accompanied by one of the most nonsensical 'hockey stick' type graphs it has been my misfortune to witness -

http://www.metoffice.gov.uk/media/pdf/p/a/quick_guide.pdf

And wasn't it Slingo who contributed to Stern's notorious "Economics of Climate Change" report, not to mention that disgraceful petition that attempted to exonerate the CRU scientists before any of the 'inquiries'.

So sorry my sympathies are definitely not with Slingo but rather with the taxpayers who have to fork out for this rubbish and the consumers who are faced with massively increasing energy bills.

[Jane Coles]

Phillip Bratby: "The whole thing is a pack of cherry-picked and distorted lies from beginning to end. Of course it was sent to John Beddington to inform Ed Miliband"

For an utterance to be a lie, it has to be both untrue and known to the speaker to be untrue. But those two conditions are not sufficient. In addition, the utterance has to be made with the intention to deceive (thus jokes, irony, satire, drama, etc. escape the net). Absent grotesque incompetence, Slingo's utterance meets the first two conditions. But it may not meet the third. If she believed that Beddington would recognize that what she said was false, then she would not have been intending to deceive him (and thus not lying). When Beddington subsequently reported what she had said to Miliband, then he would also escape any need to lie since she had indeed said what he reported her as saying.

[If your eyebrows have met your hairline as you read the above, then I urge you to return to your boxed set of "Yes, Minister" DVDs for further study.]