While the media circulates the talking points pre-release “leaked draft” of IPCC’s AR5 amongst themselves, there are a few nuggets of interest coming out here and there we can write about. One such nugget is contained in a series of bullet points on the Washington Post Capital Weather Gang in an article by Jason Samenow:
7) The 30 years from 1983-2012 was very likely the warmest 30-year period of the last 800 years.
That is an interesting statement, not so much for what it says, but for what it doesn’t say. A caveat; that’s likely the reporter’s summary, not the exact text from the IPCC “leaked draft”. IPCC verbiage tends to be a bit more bloated. But, I think it is a fair summary.
Bishop Hill points out what was said in IPCC’s AR4 in 2007:
Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1,300 years.
So, they’ve gone from saying warmest in the last 1300 years to the last 800 years. Where does that figure in on Mann’s hockey stick graph from AR3 in 2001?
![Hockey_stick_chart_ipcc_large[1]](http://wattsupwiththat.files.wordpress.com/2013/08/hockey_stick_chart_ipcc_large1.png?quality=75)
Figure 1. The hockey stick graph as it appeared in the IPCC Third Assessment Report WG1 (2001) summary, Figure 2.20, Northern Hemisphere temperature reconstruction.
So basically what they are saying is that at the year 1200 (2000AD minus 800 years), temperatures were warmer (or at least equal to) temperatures today.
This is curious, because it looks like we are back to what the IPCC said in the first report in 1990. Notice the bump, peaking at 1200AD:
![800px-IPCC_1990_FAR_chapter_7_fig_7.1%28c%29[1]](http://wattsupwiththat.files.wordpress.com/2013/08/800px-ipcc_1990_far_chapter_7_fig_7-128c291.png?quality=75)
Figure 2: IPCC 1990 FAR chapter 7 fig 7.1(c) from http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf
Compared and overlaid with Mann’s work, which was highly criticized for turning all the proxy data from 1000AD to 1900AD into a nearly straight flat shaft with an upturned blade at the end, that 1200AD bump looks like the elephant in the proxy samples room.
Figure 3: IPCC 1990, Mann 1999 and Moberg 2005 data overlaid.
- (red) IPCC hand-digitised from IPCC 1990 figure 7.1c (note: it has been assumed that the tickmarks on the y axis are in units of °C and that the middle of the three represents zero).
- (blue) Mann from ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/jones2004/jonesmannrogfig5.txt
- (black) Moberg from http://www.nature.com/nature/journal/v433/n7026/suppinfo/nature03265.html
- (green dashed line) Central England temperatures to 2007 overlaid from Jones et al. 2009 page 34 fig. 7. http://pubs.giss.nasa.gov/docs/2009/2009_Jones_etal_2.pdf
Somewhere, Hubert Lamb must be pleased that his work from IPCC’s FAR in 1990 showing a warmer Medieval Warm Period than the present is getting attention again. Steve McIntyre must also be smiling at this.
The question now is: will this inconvenient bump be flattened and sanitized in the final version of IPCC AR5?
UPDATE: WaPo’s Jason Samenow adds in comments –
I’m the author of the blog post on the IPCC report. My post just featured a handful of findings… it’s not at all comprehensive…just a teaser.
As I note in my post, I’ll dig deeper into the report once it’s finalized. As for the MWP, the IPCC says a couple things:
“Analyses of paleoclimate archives indicate that in the Northern Hemisphere, the period 1983–2012 was very likely the warmest 30-year period of the last 800 years (high confidence) and likely the warmest 30-year period of the last 1400 years (medium confidence).”
“Continental-scale surface temperature reconstructions show, with high confidence, multi-decadal intervals during the Medieval Climate Anomaly (950−1250) that were in some regions as warm as in the late 20th century. These intervals did not occur as coherently across seasons and regions as the warming in the late 20th century (high confidence).”
The IPCC stresses these statements are draft and subject to change via the government review.
Thanks for reading…
Arctic Sea Ice Concentration – 365 Day Animation – (NRL):
Arctic Sea Surface Temperature – 365 Day Animation – (NRL):
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Arctic Sea Ice Speed & Drift – 365 Day Animation – (NRL):
No longer available ?
Subject off topic: Can anyone following the literature?
Suggestions for the Explanation of Probable Connections between Solar activity and rainfall variation in Southeastern Brazil. Proceedings of the Eighth American Scientific Congress (1940)
May 1940. Washington, D.C. 1942. Vol. VII, p. 373.
Let’s be careful. The decision to use 800 rather than a longer period most likely means that they do not feel comfortable using a longer period. However, not being able to say that a current period is warmer than an older period is not the same as saying the older period is warmer. It may simply mean they accept that they cannot make a strong claim about that time period. The inference
So basically what they are saying is that at the year 1200 (2000AD minus 800 years), temperatures were warmer (or at least equal to) temperatures today.
is too strong, and does not follow from the choice of words.
It is fair to say that the IPCC wording is a rowback, and that is worth mentioning, but going too far just opens one up to a counter-claim.
MattN
I think it is fair to say they’ve made progress, and while previously they felt they could rule out the existence of a MWP warmer than today, they not longer feel that they can rule it out.
However, the statement:
This seems to me they are in a roundabout sort of way without saying it that the MWP existed and was as hot or hotter than we are today.
is, IMO, too strong.
They aren’t saying the MWP was warmer, they are saying it might have been, with a high enough probability that it cannot be ruled out.
Village Idiot says:
August 21, 2013 at 9:02 am
“(Ah, yes, Hubert Lamb, one of the first ‘alarmists’: “In 1973 and 1975 he arranged for two international conferences which were hosted in Norwich. At first his view was that global cooling would lead within 10,000 years to a future ice age and he was known as “the ice man”, but over a period including the UK’s exceptional drought and heat wave of 1975–76 he changed to predicting that global warming could have serious effects within a century. His warnings of damage to agriculture, ice caps melting, and cities being flooded caught widespread attention and helped to shape public opinion”)”
CFR / UN / CoR decided in 1971 to use environmental concerns for their globalist agenda. From that moment on government science funding in the West depended on the perpetuation of any alarmist scenario the scientists could come up with.
there is no sign of relenting. The NGO’s are still funded by the EU to keep up the pressure from above – pressure from below strategy.
I see the 800 year claim by the IPCC as a minor tactical retreat; the media will continue to show us angry Greenpeace thugs etc. Nobody in the media will talk about the tacit admission of the existence of the MWP. It can easily be ignored in the political arena.
Village Idiot:
<<<<<<<<<<<<<<>>>>>>>>>>>>>>>
I take it that you view the hockey stick as a fraud that is an embarrassment to your movement and should be covered over and hid.
Jason, next time you talk to one of your IPCC sources, why not “dig a little deeper” and ask them what physical theory and what physics-based equation they use to convert a tree metric into a temperature degree.
Here’s a prediction: they won’t have one.
Then, you digging deeper, ask, ‘If you don’t use science, then where those temperature numbers come from?‘
Prediction: complicated non-explicatory writhing that translates as tendentious re-scaling.
So, deep digging leads you to, paleo-temperature reconstructions: no physics, no science, all opportunistic statistics.
That’s the real story. Not the IPCC press releases or AR leaks
The real story is found right down there at the bottom — when you discover that paleo-temperature reconstructions are pseudo-science.
And if the IPCC is peddling pseudo-science, then what?
From the article:
Not necessarily. They could just as easily be able to say “We don’t know the global temperature before then.
I’m content to point to the warm period 5,000 – 7,000 years ago tha seems to pop up frequently, though it does predate the hockey stick. http://wermenh.com/climate/6000.html
What you could say is “Given the IPCC’s reluctance to compare to the earlier years on the hockey stick, that shows they believe the error bars should be much greater than Mann draws and that the science is not as settled as claimed.”
And the the hockey stick is somewhere under the bus.
Government review? What is the government doing reviewing scientific reports?
To bad nobody ever mentions the RATE of warming during specific periods over the last 1300 years that on many occasions exceeded the more recent rate. For example late CET 17th Century to early 18th Century (no emissions to speak of) the temp rose by 2 deg C over about 40 years.
So the IPCC are finally catching up with Richard Courtney’s email to Chick Keller (who sent it on to Mann), 18 Jul 2000
Village Idiot says:
August 21, 2013 at 9:02 am
“Clever move to keep dragging the old hockey stick out of the cupboard, Tony. It keeps the image clear in our minds – after all, it is around 15 years old.
Before you work yourself up into too much of a lather, though, isn’t it best to wait for publication?”
No, because we just learned that Mann is fighting for his reputation within the IPCC at this time. Because Alarmists do not use the word ‘falsification’, I wonder what new word they will invent if Mann loses this fight?
Hey all you guys on the other thread! Come over here! I think they found the missing hotspot!
Pat Frank says:
August 21, 2013 at 10:39 am
Brilliant post, as usual. Yes, they have done no work in physics to support their “dendro” claims. They have conducted not one experiment on proxies. Comparing one set of proxies to another does not count as an experiment.
FrankK said
“Too bad nobody ever mentions the RATE of warming during specific periods over the last 1300 years that on many occasions exceeded the more recent rate. For example late CET 17th Century to early 18th Century (no emissions to speak of) the temp rose by 2 deg C over about 40 years.”
Not so. I wrote about precisely that aspect in two linked articles that appeared here just a couple of days ago.(as referenced by Rud earlier)
http://wattsupwiththat.com/2013/08/16/historic-variations-in-temperature-number-four-the-hockey-stick/#more-91765
The Mann (and others) paleo climate proxies do not pick up the real world annual and decadal temperature which show considerable variability. This is because the paleos use ‘smoothed’ 30 and 50 year calculations that don’t find this information-in other words the paleos are very coarse sieves and the finer grain annual and decadal records fall right through the models without being seen.
The past climate being ‘smoothed’ therefore looks much more stable than it actually was when looking at the actual temperatures we all actually experience.
I suspect this also happens in other climate science fields such as ice cores
tonyb
BBould says “Which comes first — the science of climate, or the art of persuasion?
Not meant to cast aspersions on the dedicated and ethical climatologists, physicists, paleontologists, etc. who work in the field of climate study, but just how scientific is “climate science?” Maybe about the same as the “science” of psycholgy, where theories can’t be fully tested because the one quadrillion neural connections in the human brain can’t be controlled for comparative experimentation, Hypotheses predicting quantifiable global climate behavior are for the most part unprovable, even over hundreds or thousands of years into past and the future, as experimentation has been and will be fettered by an uncontrollable set of millions of climatic inputs and switches, as in the “butterfly effect.” Too many people assume that the statistical probability attributed to climate computer models is actionable certainty because of these 97% and 95% figures constantly quoted. Can we really predict solar activities and anomalies? Have we ever accurately predicted climate changes? I don’t know. It seems that Climate Science is still in the hypothesis and prediction phases, with a lot of theories, a large accumulation of data, and little scientific proof of anything. This is exactly why the AGW crisis “movement” is so unacceptable and why I am addicted to WUWT.
Jimbo says:
August 21, 2013 at 8:48 am [ … ]
I just finished reading your link:
http://themigrantmind.blogspot.com/2010/03/why-climatologists-are-not-to-be.html
Very well done, and the links within it are informative.
Mann’s hokey stick chart never was any good. It is not science; Mann will not disclose how he constructed the chart [although McIntyre & McKitrick figured it out], it is contrary to all previously published, peer reviewed literature, and the data was cherry-picked to fabricate what is a very alarming [but false] chart.
It is past time when the IPCC should have thrown Mann under the bus. He is no honest scientist.
MangoChutney:
Thankyou very, very much for your post at August 21, 2013 at 10:52 am
http://wattsupwiththat.com/2013/08/21/ipcc-throws-manns-hockey-stick-under-the-bus/#comment-1396294
which links to an email from the egregious Mann in response to having been provided by an email from me to Chuck Keller long, long ago.
I was not aware of Mann’s having seen it or having commented on it until I saw the link in your post today.
And Mann’s comments made me laugh out loud!
For example, these
Deceipt!? Mann accuses me of “deceipt” for pointing out what he had done!?
Now that IS funny!
Mike’s Nature trick (aka Hide The Decline) DID include “splicing of two different datasets” but one data set was covered by the other instead of being truncated.
I have had the honour to work with Fred Singer for many years on several things. But “hired”? How wish that were true. My contributions have almost entirely been at my own cost in time and in money.
And I could not have been – as I was – the first to point out what Mann, Bradley & Hughes (MBH) had done if I had not read their ridiculous paper.
And I love – I really love – the bluster about “for [my] sake”.
I first made a public statement (in a widely circulated email) reporting my observation (n.b. NOT a “misrepresentation”) within a week of the publication of the MBH paper in 1998. I have often repeated the observation since then including on WUWT.
It is now public knowledge and has induced many articles (including on WUWT) and much amusement such as this very funny video
But the Mann has never contacted me.
Again, thankyou for the link and the laughs it gave me. I have copied the link.
Richard
IPCC confidence is revealing itself, once again, to be negatively correlated, with high certainty, with any form of validated data.
Does anyone want to point out we were measuring temps with satellites only since 1978. How do we know if previous warm periods, such as the 30s-50s, would not have shown up warmer. The next 15-25 are going to show alot, because the pdo and then the amo will be cool again and we will be able to measure it.
While Proxies are nice, aint nothing like the real thing, and that started when this so called 30 year warmest period ever started ( sat measurements)
BTW this also takes away from the fact that even with satellites, the warming as stopped, which would fit in nicely with this being a decadol response to coming out of colder, ocean driven period. We have our test case in front of us now. Its just frustrating to see people just assume that measurements of temps in pre satellite era can simply be assumed to be as valid as now. Case in point, Noaas playing with arctic temps, which there is no way they could have known the way they do now, before the satellite era.
Nice to see ol MM tossed under the bus. Guess we’ll take what we can get. Truthfully, I’d have been shocked to see this august body who’s very existence depends on the very thing they’re entrusted to tell us is there or not, backed off in the slightest.
“So basically what they are saying is that at the year 1200 (2000AD minus 800 years), temperatures were warmer (or at least equal to) temperatures today.”
No, they don’t say that. They say that they’re not sufficiently certain that they were not warmer than today. That’s a good sign but let’s not be too enthusiastic about it.
Pat Frank says…………………..
August 21, 2013 at 10:39 am
Right on! Will Jason do as you ask? Not likely.
Jason and his ilk do not care about the truth. NO! They just keep pushing the soialist/marxist political agenda.
Give them a sandwich board and put them on the street.
Jason says:
August 21, 2013 at 8:48 am
“I’m the author of the blog post on the IPCC report. My post just featured a handful of findings… it’s not at all comprehensive…just a teaser.”
==============
A teaser for what ?
The government approved take on the science ?
You gotta be kidding me, or is their hold on you that strong ?
You thanked us for reading it….it only made me sick to my stomach.
Here’s a link to the Washington Post’s story about the leaked draft:
http://www.washingtonpost.com/national/health-science/scientists-nearly-certain-that-humans-have-caused-global-warming/2013/08/20/d6e4a20a-09b8-11e3-b87c-476db8ac34cd_story.html