Excerpts from the leaked AR5 Summary for Policy Makers

I’ve been given a copy of the “leaked” AR5 SPM, which has been widely circulated and cited in advance in the MSM, but I’ve just now been able to get a copy.  Reportedly, there are some 1800 changes requested by government participants in the upcoming meeting to hammer out the final version, so it is doubtful that what I’m posting below will be the same as the final.

Still we need a baseline for comparison, and now I have one, so that will be a future post. These are a few things that caught my eye. I’ll post them as time permits, and I don’t have time to comment today as I have other pressing issues.

First, there doesn’t appear to be a single skeptic (correct me if I’m wrong) in the author list.

AR5_SPM_page1

Atmosphere

2

3 Each of the last three decades has been warmer than all preceding decades since 1850 and the first decade of

4 the 21st century has been the warmest (see Figure SPM.1). Analyses of paleoclimate archives indicate that in

5 the Northern Hemisphere, the period 1983–2012 was very likely the warmest 30-year period of the last 800

6 years (high confidence) and likely the warmest 30-year period of the last 1400 years (medium confidence).

7 {2.4, 5.3}

8

9

10 [INSERT FIGURE SPM.1 HERE]

 

AR5_SPM_fig1

11 Figure SPM.1: (a) Observed global mean combined land and ocean temperature anomalies from three surface

12 temperature data sets (black – HadCRUT4, yellow – MLOST, blue – GISS). Top panel: annual mean values, bottom

13 panel: decadal mean values including the estimate of uncertainty for HadCRUT4. Anomalies are relative to the mean of

14 1961−1990. (b) Map of the observed temperature change from 1901−2012derived from temperature trends determined

15 by linear regression of the MLOST time series. Trends have been calculated only for grid boxes with greater than 70%

16 complete records and more than 20% data availability in the first and last 10% of the time period. Grid boxes where the

17 trend is significant at the 10% level are indicated by a + sign. {Figures 2.19–2.21; Figure TS.2}

18

19

20 • The globally averaged combined land and ocean surface temperature data show an increase of 0.89

21 [0.69 to 1.08] °C 3 over the period 1901–2012. Over this period almost the entire globe has experienced

22 surface warming. (Figure SPM.1). {2.4.3}

23

24 • Global mean surface temperature trends exhibit substantial decadal variability, despite the robust multi-

25 decadal warming since 1901 (Figure SPM 1). The rate of warming over the past 15 years (1998−2012;

26 0.05 [−0.05 to +0.15] °C per decade) is smaller than the trend since 1951 (1951−2012; 0.12 [0.08 to

27 0.14] °C per decade). (Figure SPM.1) {2.4.3}

28

29 • Continental-scale surface temperature reconstructions show, with high confidence, multi-decadal

30 intervals during the Medieval Climate Anomaly (950−1250) that were in some regions as warm as in

31 the late 20th century. These intervals did not occur as coherently across seasons and regions as the

32 warming in the late 20th century (high confidence). {5.3.5, 5.5.1}

33

34 • It is virtually certain that globally the troposphere has warmed and the stratosphere has cooled since the

35 mid-20th century. There is medium confidence in the rate of change and its vertical structure in the

36 Northern Hemisphere extra-tropical troposphere and low confidence elsewhere. {2.4.4}

37

38 • Because of data insufficiency, confidence in precipitation change averaged over global land areas since

39 1901 is low prior to 1950 and medium afterwards. The incomplete records show mixed and non-

40 significant long-term trends in global mean changes. Precipitation has increased in the mid-latitude land

41 areas of the Northern Hemisphere since 1901 (medium confidence prior to 1950 and high confidence

42 afterwards). {2.5.1}

43

44 • Changes in many extreme weather and climate events have been observed since about 1950 (see Table

45 SPM.1). It is very likely that the number of cold days and nights has decreased and the number of warm

46 days and nights has increased on the global scale. In some regions, it is likely that the frequency of heat

47 waves has increased. There are likely more land regions where the number of heavy precipitation events

48 has increased than where it has decreased. Regional trends vary, but confidence is highest for North

49 America with very likely trends towards heavier precipitation events. {2.6.1, 2.6.2; FAQ 2.2}

 

 

3 In the WGI contribution to the AR5, uncertainty is quantified using 90% uncertainty intervals unless otherwise stated. The 90% uncertainty interval, reported in square brackets, is expected to have a 90% likelihood of covering the value that is being estimated. The upper endpoint of the uncertainty interval has a 95% likelihood of exceeding the value that is being estimated and the lower endpoint has a 95% likelihood of being less than that value. A best estimate of that value is also given where available. Uncertainty intervals are not necessarily symmetric about the corresponding best estimate.
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Ken
September 16, 2013 12:43 pm

Is there a link to the full PDF anywhere?

Neil
September 16, 2013 12:46 pm

It would be very interesting to have a detailed list of the 1800 government- proposed changes…

FerdinandAkin
September 16, 2013 12:46 pm

Remind me again how much money the IPCC has spent documenting the Earth is warming out of the Little Ice Age.

September 16, 2013 12:48 pm

Figure SPM.1 (b), the Change in Global Surface Temperature 1900-2012 is an abomination on many dimensions:
1. there is no indication of sample density. Most of the cells have no measurements but are calculated by gridding neighbors.
2. Who believes that we have measurements of any quality for the first two decades of the 1900-2012 date range over even 30% of the globe?
3. Isn’t it strange that the one place where we probably have good ocean surface temperatures in the early 1900’s, The North Atlantic shipping lanes between NY and Europe, is the only place showing a cooling? What a coincidence!
4. the color scale: Abominable. First the colors bounding the zero are highly contrasting. These should be neutral and no greater in contrast than any other 0.2 deg C (i.e. 0.019 deg C per decade) interval.
5. Color scale units are “the entire measurement period.” Not deg C per decade. Not even deg C per century. But Deg C from 1900 to 2012.
6. What was the smoothing in time? What is being measured? The least squares slope of the temps? The line between two averaged points in time?
This map is all hype, advertizing, marketing, and devoid of science.

September 16, 2013 12:52 pm

Fig. SPM.1 (a) Decadal Average:
“Pause? What Pause?”

Pippen Kool
September 16, 2013 12:53 pm

The decadal average is pretty interesting. The last century can be summarized with three straight lines.

kadaka (KD Knoebel)
September 16, 2013 12:53 pm

First, there doesn’t appear to be a single skeptic (correct me if I’m wrong) in the author list.
Why include dissidents in the writing of a political position statement?

Jimbo
September 16, 2013 12:57 pm

45 SPM.1). It is very likely that the number of cold days and nights has decreased and the number of warm
46 days and nights has increased on the global scale.

Has it or hasn’t it? What use are the satellites?
I’m sensing cherry picking. Picking those bits that back up the case for CAGW. In the meantime Peru is suffering and has been for the past few years. So have many Europeans. Those warm nights are terrible.

milodonharlani
September 16, 2013 12:58 pm

Thirty years warming in first half of 20th century looks similar to 30 years warming in second half, even with major adjustments to that century’s really hottest decade, the 1930s. All without benefit of extra man-made carbon dioxide.

Miboupop
September 16, 2013 1:22 pm

Being French, I wanted to check who the French authors are among the drafting authors of the AR5 report. Well, the very first French is François-Marie Breon. Here is what I find on the web site of his “digital university” in France (http://www.uved.fr/ouvrage-numerique/differentes-entrees/auteurs-des-modules.html):
“François-Marie Bréon est persuadé du danger du changement climatique. Il a donc choisi d’être un militant écologique actif dans le but de diminuer les émissions de gaz carbonique. Ainsi, il fait de nombreuses interventions pour faire prendre conscience au grand public de la nécessité d’un changement du mode de vie.”
English translation: “F-M Breon is certain of the danger of climate change. This is why he has chosen to be an alert ecologist activist with the aim to reduce CO2 emissions. He makes many speeches to make people understand the necessity of a change in our lifestyle.”

kadaka (KD Knoebel)
September 16, 2013 1:25 pm

The figure mentions the MLOST temperature dataset. This is a NOAA/NCDC product, the “Merged Land-Ocean Surface Temperature Analysis”, info and data found here:
http://www.ncdc.noaa.gov/ersst/merge.php
This is the merging of the GHCN land-only non-satellite dataset, with the ERSST v3b ocean temperature dataset which is noted on that page as not containing satellite data.
See a trend? The satellites don’t show warming that’s as alarming nor are open to the manipulations done on the surface-based data. The ALARMING UNPRECEDENTED figure has excluded satellite data completely. Want to guess why?

milodonharlani
September 16, 2013 1:34 pm

kadaka (KD Knoebel) says:
September 16, 2013 at 1:25 pm
You’re right that there is no good reason not to tack onto the longer series the satellite data since 1979:
http://www.drroyspencer.com/latest-global-temperatures/
No reason except the same one as to why the adjusted data sets that are shown differ so markedly from the raw data, & always in the direction of greater warmth for recent years & cooler for more distant. And why adjusting for urban heat islands makes the temperatures hotter instead of cooler.

Harry
September 16, 2013 1:34 pm

It must be hard to create good presentations when the only colours you can use over a very narrow range are varieties of red. If only there was a larger colour palette visible to humans.
But perhaps I misinterpret the intent, I would have thought clarity would be the objective rather than alarm.

Crispin in Waterloo but really in Beijing
September 16, 2013 1:36 pm

If I wanted to reflect rapid warming, increasing with time, I would also pick 1951 as a starting point so the cooling in the early part of the period would accentuate the appearance of a rise with industrialization.
Starting in, for example, 1930 would yield quite a different set of final figures because that would be taking a different analysis length on a cycle of about 60 years.
Given people’s predisposition to allow others to do their thinking for them, I think the presentation is pretty well worded, meaning it will be effective in communicating alarm without saying too much that is specific.
I am sure there will be no mention of the tapering and stalling of temps in the past 17 years. Now would be a good time to stop writing these things because it is going to be very difficult to explain a 30-40 year ‘pause’ with colder temps all round.
I see they are trying to fly the “MWP was not global” balloon (as opposed to Mann’s ‘not there’). That surely is a reaction to the investigations of the skeptical community. Shouldn’t take much to pop it.
Remember how far we have come: from MBH98 to Svensmark13. Congratulations everyone.

Mike Haseler
September 16, 2013 1:46 pm

Whoever thought it would be impartial? It is a party manifesto for the warmist party!

milodonharlani
September 16, 2013 1:48 pm

In the statement below the phrase “in some regions” & its last sentence are lies & the perpetrators of IPCC must know it to be so:
29 • Continental-scale surface temperature reconstructions show, with high confidence, multi-decadal
30 intervals during the Medieval Climate Anomaly (950−1250) that were in some regions as warm as in
31 the late 20th century. These intervals did not occur as coherently across seasons and regions as the
32 warming in the late 20th century (high confidence). {5.3.5, 5.5.1}
That both the LIA & MWP were global has been well established for decades & never falsified. Same goes for previous cold & warm periods during the Holocene, & of course the Eemian Interglacial was much warmer than the Holocene. To take but one paper among the many to this effect:
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Glacial.pdf

September 16, 2013 1:53 pm

IPCC AR5 leak:
Each of the last three decades has been warmer than all preceding decades since 1850 and the first decade of the 21st century has been the warmest.
Using their decadal average graph of temperature anomalies since 1850 (Figure SPM.1), I’d like to put that preceding statement in perspective.
Token alarmist, circa 1880:
The decade of 1870 to 1880 has been warmer than all preceding decades since 1850 and is the warmest on record.
Token alarmist, circa 1930:
The decade of 1920 to 1930 has been warmer than all preceding decades since 1850 and is the warmest on record.
Token alarmist, circa 1940:
The decade of 1930 to 1940 has been warmer than all preceding decades since 1850 and is the warmest on record.
Token alarmist, circa 1950:
Each of the last three decades has been warmer than all preceding decades since 1850 and the decade of 1940 to 1950 has been the warmest.

lemiere jacques
September 16, 2013 2:01 pm

Miboupop
sure and when i wanted to check about he first ion the list
i found that http://nofrakkingconsensus.com/2010/10/18/the-non-stop-ipcc-spin-machine/
and this http://www.climatescience.org.au/staff/profile/lalexander
you have to admire “the climate change research center” they are nit cilmatologist anymore climatechangologist

Steve Oregon
September 16, 2013 2:05 pm

(correct me if I’m wrong)
Ya sure never hear that from the other side.
I wonder why that is?

Werner Brozek
September 16, 2013 2:09 pm

Each of the last three decades has been warmer than all preceding decades since 1850
That is true, but it is noteworthy that the statement would not be true had they said “four decades”. When it suits them, they talk of the last three decades, but when it does not suit them, they base anomalies on very different decades such as GISS: “base period: 1951-1980”
On Hadcrut4, the average from 1940 to 1950 was -0.0029, but the average from 1973 to 1983 was -0.02398. So it was cooler 33 years later. See:
http://www.woodfortrees.org/plot/hadcrut4gl/from:1940/to:1950/plot/hadcrut4gl/from:1973/to:1983

Latitude
September 16, 2013 2:31 pm

why would they include skeptics?? You guys seem to forget who they are….
“…to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change”

Jean Parisot
September 16, 2013 2:34 pm

How big is the whole document? Can we crowd source a response or re-write?

RACookPE1978
Editor
September 16, 2013 2:49 pm

Interesting that the “purple” regions (the areas of highest continental temperature rise) are all heaviest forested! Amazon and hills between the Amazon basin and south Atlanta coast, upper Canadian forest, central Africa, Siberia, etc.
One area near the Atlas Mountains of the Sahara is the only region that matches the highest regions of the world of high CO2 concentrations: CO2 is always highest over deserts, lowest where the trees are growing. .

September 16, 2013 2:50 pm

I don’t know what numbers they use. I’m just a guy. (A Joe Six-pack?) But I do know that the temperature records for my little spot on the globe have been tampered with (“adjusted”, if you prefer) between March of 2007 and April of 2012. Specifically, record highs and lows in 2012 are often different than they were in 2012. Not old records broken, old records changed.
I have no confidence in recent reports of temperature records.

September 16, 2013 2:53 pm

Specifically, record highs and lows in 2012 are often different than they were in 2012.

=============================================================
WOW! That was quick! Make that”
“Specifically, record highs and lows in 2012 are often different than they were in 2007,/b>.”

September 16, 2013 2:55 pm

(Usually when I go for “comic relief” it’s intentional.)

Jimbo
September 16, 2013 3:43 pm

That Warm period was not as warm as today. This is really bad and we must act now.

Medieval Climatic Optimum
Michael E Mann – University of Virginia, Charlottesville, VA, USA
It is evident that Europe experienced, on the whole, relatively mild climate conditions during the earliest centuries of the second millennium (i.e., the early Medieval period). Agriculture was possible at higher latitudes (and higher elevations in the mountains) than is currently possible in many regions, and there are numerous anecdotal reports of especially bountiful harvests (e.g., documented yields of grain) throughout Europe during this interval of time. Grapes were grown in England several hundred kilometers north of their current limits of growth, and subtropical flora such as fig trees and olive trees grew in regions of Europe (northern Italy and parts of Germany) well north of their current range. Geological evidence indicates that mountain glaciers throughout Europe retreated substantially at this time, relative to the glacial advances of later centuries (Grove and Switsur, 1994). A host of historical documentary proxy information such as records of frost dates, freezing of water bodies, duration of snowcover, and phenological evidence (e.g., the dates of flowering of plants) indicates that severe winters were less frequent and less extreme at times during the period from about 900 – 1300 AD in central Europe……………………
Some of the most dramatic evidence for Medieval warmth has been argued to come from Iceland and Greenland (see Ogilvie, 1991). In Greenland, the Norse settlers, arriving around AD 1000, maintained a settlement, raising dairy cattle and sheep. Greenland existed, in effect, as a thriving European colony for several centuries. While a deteriorating climate and the onset of the Little Ice Age are broadly blamed for the demise of these settlements around AD 1400,
http://www.meteo.psu.edu/holocene/public_html/shared/articles/medclimopt.pdf

Gail Combs
September 16, 2013 3:59 pm

Interesting that the Koppen decadal climate boundaries say something completely different. link

September 16, 2013 4:17 pm

IT IS ALL GARBAGE.
It is not worth the paper it is written on.
That is my opinion of the latest IPCC assessment.

TomRude
September 16, 2013 4:30 pm

Hadcrut 4… makes 2005 warmer than 1998… anything helps

Katherine
September 16, 2013 4:39 pm

34 • It is virtually certain that globally the troposphere has warmed and the stratosphere has cooled since the
In other words, after a lot of massaging of the data, the models say the tropospheric hot spot should be there.

RC Saumarez
September 16, 2013 4:44 pm

55 Authors. What percentage of climate scientists is this? I not that Tim Osbourne is a contributing author, After publication of the “Harry_READ_ME” file, I’m surprised to see him here.

RC Saumarez
September 16, 2013 4:50 pm

I’m sorry, I forgot add:
What the hell is the 90% certainty? in most sciences, the two tailed probability is taken as significant at +- 2SD, i.e.: the cumulative probability is 2.5% beyond each tail and the probability is 1 in 20 as being from the observed distribution.
Not only has climate science managed to screw up temperature records, they are now playing fast and loose with basic statistical reasoning..

JPeden
September 16, 2013 5:03 pm

“I’ve been given a copy of the “leaked” AR5 SPM, which has been widely circulated and cited in advance in the MSM, but I’ve just now been able to get a copy.”
You’re lucky at that, because you are just going to “try to find something wrong with it.”

Goldie
September 16, 2013 5:32 pm

I sense a moving of the goal posts here – most of the stuff I hear is about how the temperature is rising so quickly over the last 30 years. Now all of a sudden we are moving to consider that the 20th century was warmer than other centuries.
The thing is, that I see there is some kind of surrender on the instrumental record and now with “virtual certainty” the last, instrumented, century is warmer than all of the other non-instrumented centuries.
I am unsure how one gets virtual certainty when there was no instrumental record, but its going to be very difficult to prove or disprove.

JPeden
September 16, 2013 5:51 pm

September 16, 2013 at 4:44 pm
RC Saumarez says:
“55 Authors. What percentage of climate scientists is this?”
According to one earlier study [Doran?] there were only about 77 “climate scientists” found, 75 of which agreed that ~”the world is warming and that humans might have something to to with it” = 75/77 = 97%.. But now it appears that the ipcc can’t find the other 22, so that the 55 might be all there are left today, as defined by Doran! Fortunately for the ipcc and still using “mainstream” Climate Science’s “method”, this means its “certainty” of our impending doom is still a healthy 53-55/55, or as much as 100%!/sarc
[(53+55)/55 ? 8<) Mod]

Robber
September 16, 2013 6:09 pm

Wow, three expert authors from Australia:
Dr Lisa Alexander
Chief Investigator
Climate Change Research Centre
Mathews Building University of New South Wales SYDNEY 2052 Australia
Dr Alexander’s primary research focusses on understanding the variability and driving mechanisms of climate extremes. Of particular significance is her ongoing work assessing global changes in temperature and rainfall extremes, which has contributed significantly to the Intergovernmental Panel on Climate Change (IPCC) Assessments.
Professor Nathaniel Bindoff
University of Tasmania
Professor Bindoff is a physical oceanographer specializing in ocean climate and the Earth’s climate system. He is a prominent researcher who has worked to quantify the changing state of the global ocean through analyses of new oceanographic data sets and simulations. He has documented some of the first evidence for changes in the climate change signals in the Indian, North Pacific, South Pacific and Southern Oceans and has shown some of the first evidence of changes in the Earth’s hydrological cycle.
Dr John Church
Leader, Sea Level Rise Program
University of Tasmania
John Church is an oceanographer with the Center for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research and the Antarctic Climate and Ecosystems Cooperative Research Centre. He has published across a broad range of topics in oceanography and his area of particular expertise is the role of the ocean in climate, particularly anthropogenic climate change.

Niff
September 16, 2013 6:20 pm

RC Saumarez and JPedan. Indeed the IPCC have already admitted that the “certainty” is based on the opinions of the authors….nothing scientific or statistical in it at all.

OldWeirdHarold
September 16, 2013 6:44 pm

Aside from the sensationalistic visuals, I don’t see much controversial there. Warmer than the LIA? No shirt, Shylock?

September 16, 2013 7:40 pm

1800 changes …??? … I’m listening to the same voices ….. always …. Fernando….. Fernando …. You are out of date……the nightmare continues …..

Pete of Perth
September 16, 2013 7:43 pm

Robber
You forgot Steve Rintoul CSIRO
Dr Rintoul is a physical oceanographer studying the role of the ocean in the Earth’s climate system, with a particular interest in the Southern Ocean.
His current interests include:ocean currents and how they affect Earth’s climate
the Southern Ocean and the Antarctic Circumpolar Current
how ocean currents influence sea ice, biogeochemical cycles, and the distribution of biological productivity. Dr Rintoul was awarded the inaugural Georg Wüst Medal by the German Society of Marine Research in 2005.

Henry Clark
September 16, 2013 7:50 pm

First, there doesn’t appear to be a single skeptic (correct me if I’m wrong) in the author list.
When, for instance, Mann was richly rewarded (or, for example, how the Gleick affair turned out), some (good people) were disgusted, but others got the message loud and clear, flocking to the opportunities for them. By this point, the set of individuals calling themselves climatologists is no longer remotely like a random sample of a broad populace, and everyone who naively extrapolates assumptions of honesty prevalence based on experience in more ordinary contexts has no idea whatsoever.
Going from having skeptics in earlier reports to none is of note but totally unsurprising, for, in circumstances like this, ideological polarization applies, getting worse and worse over time by default. Those trying to enforce CAGW-movement convenient views will be behind the scenes actively attacking and trying to drive away purveyors of other information, for dishonesty is never secure until divergence from the group is suppressed, until particular facts are never spoken, posted, or distributed (as seen, attempted or successful, in online community after community, for instance, most of which have nothing to do with climate but for which similar psychology applies).
Nothing short of more and much more global cooling, beyond the capability of anyone to fudge away, will necessarily be saving in the future at this point, for more and more every last major inconvenient dataset gets rewritten. (Temperature, cloud cover, solar activity, humidity, and sea level history are all among examples).

Richard M
September 16, 2013 8:11 pm

No one argues that is warmed in the late 20th century. The issue is what caused the warming. I see nothing in these statements that discusses attribution. Are they just going to ignore that topic?
Most of us know that ENSO is a major part of that warming. It appears they will just stare blankly into space whenever the topic is brought up.

Louis
September 16, 2013 8:21 pm

“In some regions, it is likely that the frequency of heat waves has increased.”

Saying “some regions” is not the same thing as saying “most regions,” so I would have to assume that most regions are not seeing an increase in the frequency of heat waves and may even be seeing a decrease.
They use the word “likely” a lot. That tells me they’re guessing and don’t have reliable data. Are they basing their assumptions on climate models rather than actual observations?

TalentKeyHole Mole
September 16, 2013 9:18 pm

Oh Dear indeed.

September 16, 2013 11:10 pm

All the given information is fine… But can someone explain me how the measurements were taken over the globe in the time period like a 1900 or even back where there were no instrumnets. Don’t get me wrong iam a noob.

kadaka (KD Knoebel)
September 17, 2013 5:06 am

srinivas2036 said on September 16, 2013 at 11:10 pm:

All the given information is fine… But can someone explain me how the measurements were taken over the globe in the time period like a 1900 or even back where there were no instrumnets. Don’t get me wrong iam a noob.

The real answer is, they weren’t.
The parts of the surface of this planet that aren’t large bodies of water are only about 30% of the surface area. This includes large places like the Antarctica continent that never has had nor ever will have enough thermometers on the ground for a trustworthy record.
Of the remaining land, the US has arguably good coverage of volunteer temperature takers who sent in their daily measurements. Quality wise it’s better than nothing. In there were readings from many airports, which went from grass strips to dirt to tarmac, and tarmac heats up very well in sunlight and releases that heat slowly at night. Likewise many individual thermometers started as purely rural, then civilization grew up around them with heated buildings, brick and concrete, and more tarmac. Amazingly enough, “global warming” has largely shown up as warmer nighttime temperatures.
Other places, perhaps all you’ll get is a record taken from outside the Ministry of Agriculture headquarters or similar, completeness and quality of records highly questionable.
From this a “global” record is built on assumptions, mainly that a spot between two temperature stations will be similar to them. Thus a deep shaded river valley is to be similar in temperatures to the two airports on flat ground it is between, a mountain is similar to stations in valley towns, a swamp is similar to dry ground, etc.
For the oceans, there are some records of water temperatures taken by crews on seafaring ships, with a water temperature at the surface close enough to a surface air temperatures as taken on land. Thus there are sparse but useable records of the usual trade routes, but not elsewhere. Add more assumptions.
They throw all this into the computers, top off the pixie dust dispenser, and from this a global land+sea average temperature dataset is crafted, as with those used above for the IPCC figure. They also change the recorded readings based on many assumptions, which they call “adjustments” and insist are needed. Which invariably make the older readings suddenly become colder, “proving” there is a threatening large rate of warming.
Hope this helps.

thomam
September 17, 2013 6:05 am

Louis says:
September 16, 2013 at 8:21 pm
“In some regions, it is likely that the frequency of heat waves has increased.”

Saying “some regions” is not the same thing as saying “most regions,” so I would have to assume that most regions are not seeing an increase in the frequency of heat waves and may even be seeing a decrease.
=============================================
This is the same linguistic dexterity that advertisers use – “Surveys show that some of our customers could save up to 30%”. There are three distinct qualifiers in that sentence, rendering it utterly meaningless.
Likewise the “some regions” and “likely” qualifications here. The IPCC is desperately trying to sell its message, so is reduced to using the tricks of the advertising agency.

September 18, 2013 2:29 am

Get things in perspective !!!
The last millennium 1000 – 2000 AD was the coolest of the whole Holocene epoch and in the last ~10,000 years the world has cooled about -1.5degC overall.
And in the UK the MO CET has lost about -1 degC since 2000 and even more in the winter and spring of 2013.
Look at the sunspot cycle its going downhill fast.
The future is cold.

Brian H
September 20, 2013 1:53 am

Niff says:
September 16, 2013 at 6:20 pm
RC Saumarez and JPedan. Indeed the IPCC have already admitted that the “certainty” is based on the opinions of the authors….nothing scientific or statistical in it at all.

Indeed; incredible as it seems, the consensus ‘expert opinion’ was cooked up first, then numbers appended to make it sound scientificy.
Green Jelly Beans Cause Acne – 95% confidence.