By Paul Homewood
In an attempt to downplay the recent halt in global warming, the IPCC have claimed in their Summary for Policymakers that:
As one example, the rate of warming over the past 15 years (1998–2012; 0.05 °C per decade), which begins with a strong El Niño, is smaller than the rate calculated since 1951 (1951–2012; 0.12 °C per decade.)
Simply translated, this means that warming has slowed down to just under half what it was before. This message has been quickly picked up by the media, which, of course, was the main intention.
The dreadful Geoffrey Lean comments in the Telegraph:
The IPCC did, however, address a much more substantial sceptical point, that the temperature increase at the Earth’s surface has slowed down since 1998 to about 40 per cent of its average rate since 1951 – something it accepts it didn’t predict. One reason is that 1998, the year invariably chosen by sceptics, was one of the warmest ever.
So, at a stroke, the “pause” has become a “slowdown, but still significant” in the public’s eyes. But look deeper, and you will see this is a piece of devious trickery.
Is 1998 the best place to start?
First, let’s get rid of the 1998 red herring. The implication is that you can only get this “slowdown” by picking 1998 as the start year. The reality is that temperatures have been flat since 2001, which was a neutral ENSO year, and therefore comparable to this year. The Wood For Trees graph below shows this well.
Figure 1
They could also have mentioned that RSS satellite data actually shows a drop in temperature since 1998, not the small (and statistically insignificant) amount shown by HADCRUT4.
Figure 2
http://www.woodfortrees.org/plot/rss/from:1998/to:2013/trend/plot/rss/from:1998/to:2013
Longer term trends
But much more important than this attempt to deflect attention form the pause, is the way the IPCC have totally misrepresented the longer term trends. Figure 3 shows HADCRUT4 numbers going back to 1941.
Figure 3
Spot what they have done? Their base period of 1951-2013, against which they have measured post 1998 trends, includes:-
- 28 years of cooling – 1951-79
- 22 years of warming – 1979-2001
- 12 years of cooling again – 2001-2013
So, in total, during 40 out of the 62 years there has been a cooling trend. They are comparing a statistically insignificant amount of warming since 1998, with three decades of cooling. The result is to make this small trend sound much more significant than it is.
It would surely have been more honest to have compared the post 1998 trend with the 1979-98 period. If they had have done this, of course, most people would realised that the much trumpeted global warming really had stopped for the time being. And, in the IPCC’s eyes, that was not the message they wanted people to hear.
By this dodgy use of statistics and the 1998 red herring, they have also tried to distract attention from the clear fact that temperatures really have flatlined since 2001.
How temporary is the “temporary pause”?
It is commonly argued that a short pause in warming, of a decade or so, is not unexpected, amidst all the natural variability.. Back in 2010, the UK Met Office commented:
Recent Met Office research investigated how often decades with a stable or even negative warming trend appeared in computer-modelled climate change simulations.
Jeff Knight, lead author on the research, says: “We found one in every eight decades has near-zero or negative global temperature trends in simulations. Given that we have seen fairly consistent warming since the 1970s, the odds of one in eight suggest the observed slowdown was due to happen.”
But, if you go back to 1941, you have actually got 50 years of near zero or negative trends, and only 22 years of warming.
So which is the norm, and which is the rarity?
Footnote
It appears that the IPCC’s Thomas Stocker now claims that climatic trends should not be considered in periods of less than 30 years.
I don’t remember the IPCC suggesting that after just a decade of warming, when they wrote their first report.
A) I don’t like WoodForTrees’ Figure 3 because the discontinuous line segments tend to down-play the upward trend (in both cases the discontinuity is upward to the right).
B) The misleading summaries issued by the IPCC will only work for so long. Eventually (and this is already happening) reporters will actually look at the data. Presumably those who rely heavily on global-warning grants and speaking engagements know this, and they know that when the cat is out of the bag they will have to go back to real science, so they are just trying to keep up the facade as long as possible to pay off the condo, etc.
C) CBC (always keen on supporting the left-wing agenda) had an interview on Quirks and Quarks about the IPCC report. They interviewed two pro-IPCC scientists who made it sound like there was absolutely no problem with the models.
According to figure 3, they used the coldest year as their start point. Any other reason for such an odd number of years like 62 ?
galileonardo says: “The bigger question is why are you unable to accept that the cooling trends over the last 70+ years have lasted nearly twice as long as the warming trend?”
How can this be a “bigger Q” when the temperature is warmer after 70 years? You sound like the explorer boiling in the cannibal pot saying it’s not so hot, this pot has been getting cooler for 23 of the last 24 hours.
Pippen the Hater, your entire argument is based on unmeasurable assertions. That fails here at the internet’s “Best Science” site. So run along back to Pseudo-skeptical pseudo-science, they like unmeasurable assertions there.
And FYI, the planet has been warming naturally since the LIA. Doesn’t matter if CO2 is low or high, the warming is repeated exactly. Thus, the alarmist fantasy is once again debunked.
Paul, the thing is the IPCC is grasping at the oddest of straws. But almost nobody gets this! Only sentient beings. Of which there are precious few these days. Of course the MSM picks up on whatever allusion the IPCC deigns to make. They are journalists, not scientists, what else can they do but respond to authority perceived to be beyond their ken? Well, they COULD do what a lot of non-scientists do here at WUWT, pay attention, and with as much “ken” as any of us can muster, expand their knowledge base.
Very few “journalists” even bother post-Nixon. And why should they? Marx would appear to have been correct, the proletariat. If you were a low information journalist, why would you suffer the angst of attempting to inform the lower information proletariat of things you cannot be bothered with understanding, in all of its sundry detail? Probably because they consider themselves journalists, the in-the-know class. Assuming they “know” anything other than that they are told too.
And that is the problem.
The IPCC assessment reports are supposed to be an assessment of the state of the literature, the research. Since AR4 (or AR3 for that matter), the literati have been treated to an astonishing array of things climate which make the IPCCs “worst case” scenario (+0.59 meters sea level rise by 2099) pale in comparison to an order of magnitude plus higher than that (+6.0 meters) end extreme interglacial normal climate noise at the end of the last interglaciation.
But how many amongst use even know what an interglaciation is?
Sure, most all of us know to turn down the volume if someone of some authority attempts to communicate with us (wife, child, boss etc……). But how many of us? How many journalists, nowadays, could give even a layman’s cogent description of signal to noise ratio? And how many lay men and women would glom-on to it even if they could?
Innately, we all actually do understand signal to noise. We just have not been apprised, by the cognoscenti of the import here. Because few of them get-it either.
Whilst that may appear to be a potentially bad thing, such might be far from another potential eventuality. The sun went all quiet on us, and the PDO went negative, a few years ago now. The AMDO is likely to follow soon. And all at the half-precession (plus a few centuries and change) old Holocene. One can only hope that there is a silver-lining in each end extreme interglacial…….
The possibility consequently exists that both those in “authority”, and those enamored of authority (maybe even their progeny) could come to the exact wrong conclusion. Regardless of whether or not CO2 is the heathen devil gas it is made out to be, the only relevant questions to be asked are:
1) Does the possibility exist that we could extend the current interglacial by some other means than GHGs?
or
2) Assuming that we don’t, and there isn’t, will the version of the genus Homo that emerges from the next glacial be better at discerning the difference between fact and fiction?
Because if we haven’t already hidden the decline, we better get very serious, and very real, about doing exactly that…………
It hasn’t been that long ago they were still harping acceleration of warming, OMG, we’re doomed.
http://wattsupwiththat.com/2013/06/28/is-it-time-to-prosecute-the-ipcc-for-fraud/
it has been COOLING SIGNIFICANTLY SINCE 2010….just three years…if it persists…the trend will fit a 30/60 year cycle…warming 1919-1950…cooling 1950-1980…warming 1980-2010…cooling since…no supercomputer needed for this model…just paper and pencil
Sippen Kool-Aid says:
September 29, 2013 at 8:25 pm
How can this be a “bigger Q” when the temperature is warmer after 70 years? You sound like the explorer boiling in the cannibal pot saying it’s not so hot, this pot has been getting cooler for 23 of the last 24 hours.
It’s the bigger question because that happens to be the subject of this thread and it’s something you are apparently unprepared to address. Your sad “but look it’s hotter” straw man has been put to bed countless times here. dbstealey tries to persuade you to look at the data since the LIA and shows you the historical warming trends that one of your heroes Phil Jones agreed were “not statistically significantly different from each other” but obviously none of that empirical stuff is sinking in. You have your beliefs and ego to protect. Never yield an inch.
Now go run off to SS and gather your next thoughts about how the LIA doesn’t matter and how the former warming trend (as in the trend that ended over a decade ago) is different this time and come back for another round. Just know in advance that through the exercise you will have learned nothing other than how to beat a dead horse. I have done this more than once as of late, but here goes again since you apparently need the lesson.
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 on record.
Cheers!
When do we start officially calling it the “Former Warming Period” or “Recent Warming Period”? It doesn’t warrant the name “Current Warming Period” anymore. MWP will persist, but I’m afraid CWP is ready for retirement. Bring on the RWP.
Latitude cited that climatic trends should not be considered in periods of less than thirty years.
For what reason then do we need the deep-ocean explanation?
The latter implies that something has to be explained regarding the past 17 years or so.
Is it true that all those model simulations were done as a test of the null hypothesis that
the deep oceans do not absorb heat?
I very specifically remember warning the 0nline warmists in 1999-2000 not to use the record breaking El Nino as ‘proof’ of man made global warming. I cautioned that it would bite them in backside when the following years did not show any warming. They, of course, continued to use the El Nino heat to generate their ‘trend lines to doom’ in all the reports.
So when they cry foul when skeptics use 1998 to define the length of the halt, just remind them that we are only following their lead and their methods. Of course, we don’t need to use 1998. All the years after that work just as well. Soon, the trend will be unmistakably down, and all of this will be a mute point.
CRS, DrPH says:
September 29, 2013 at 5:40 pm
“…what is the mechanism for heat to reach the deep ocean?”
It is the Immaculate Convection. Somehow, the heat was teleported to the depths without leaving any trace of its passage through the upper layers. I suspect some cowboy Captain disregarding Star Fleet orders again.
“And, if it is so obvious, why haven’t the climatology folks brought this up in the past & included the phenomenon in their models?”
Because, shut up. Really. That’s their answer.
Luke Warmist says:
September 29, 2013 at 6:32 pm
“while co2 continued rising like a homesick angel… I recognize what’s in the bowl they’re trying to give me ain’t food.”
Thanks for the laughs.
“It appears that the IPCC’s Thomas Stocker now claims that climatic trends should not be considered in periods of less than 30 years.
I don’t remember the IPCC suggesting that after just a decade of warming, when they wrote their first report.”
Don’t remember? But did you read it? They did say something quite like that (FAR SPM p xxiv):
“The observed increase could be largely due to natural variability, alternatively this variability and other man-made factors could have offset a still larger man-made greenhouse warming The unequivocal detection of the enhanced greenhouse effect from observations is not likely lor a decade or more, when the commitment to future climate change will then be considerably larger than it is today.”
@Nick Stokes – a “decade or more” is nowhere near “no less than 30 years”!!!! That is a 200% error margin!
200% Phil?
That’s quite good for climate scientists!
I am a sceptic but the third graph in this posting seems to me to give more support to the warmists than the sceptics since the amount of warming in the period 1980-2000 is obviously a lot greater than the cooling before that and the cooling in the past decade.
A.D. Everard says:
Not one of them suggested waiting ANY number of years – not 15 and certainly not 30. If and when we reach the 30-year mark, they’ll start insisting on 50 years and we all know it.
Possibly 45 or 60… Keep moving the “goalposts”.
Of course after those 30 years the PDO will have moved back into its warm phase, so we’ll probably see some “warming” by then anyway.
Galileonardo:
At September 29, 2013 at 9:51 pm you write in total
Respectfully, I suggest that it is correct to say
we are in the Present Warm Period(PWP)
that has followed recovery from the Little Ice Age (LIA)
which most recently included the Ended Warming Period (EWP).
This terminology cannot be rationally disputed and will enrage the irrational (e.g. Pippen Kool) because it is unarguably true.
Richard
Martin 457 says:
Every time somebody pulls a tree or plant matter from underneath a receding glacier, I giggle.
You mean it was actually this warm along time ago? How did that happen?
There are the remains of buildings being found in such places. Even the odd human body!
Paul, please don’t mention Geoffrey Lean in polite company. It spoiled the breakfast I was having on the train from North Wales to London!
Good article otherwise
Nick Stokes:
Your post at September 29, 2013 at 11:34 pm is disingenuous.
In response to a comment saying
<blockquote <blockquote “It appears that the IPCC’s Thomas Stocker now claims that climatic trends should not be considered in periods of less than 30 years.
You reply
The quotation does NOT say there could be a halt to warming “for a decade or more”.
It says, “The UNEQUIVOCAL DETECTION of the enhanced greenhouse effect from observations is not likely for a decade or more” FROM THEN.
But the “unequivocal detection” has not been obtained after more than two decades. So, you have attempted to pretend a failed IPCC prediction is a successful prediction of something else!
Richard
@UnfrozenCavemanMD: discreet jumps (step changes) in temperature are not indicitive of CO2. A real sceptic wouuld have researched this simple fact before making accusations of dishonesty. I think we can all see now who is being dishonest.
richardscourtney says: September 30, 2013 at 12:15 am
“The quotation does NOT say there could be a halt to warming “for a decade or more”.”
I never said it did. What it does say in 1990 is that, after more than a decade of warming, we’ll still have to wait a decade or more to tell. They aren’t predicting the future temperature; they are describing the requirement for “unequivocal”. And it’s not inconsistent with Stocker’s, and made at a time of rising temperature.
Who are these “scientists” meeting behind closed doors in Stockholm and telling us what to think.
Could we please have a list of delegates, after all they are there on the taxpayers dime.
Fig 3. looks like a sine-wave with a slight upwards trrens to me. And we all know what happens to a sine-wave, after the peak is past.
Can none of the IPCC ‘scientists’ see this?
Nick Stokes:
Your post at September 30, 2013 at 12:34 am simply will not do!
My post at September 30, 2013 at 12:15 am explained how you had blatantly misrepresented the FAR SPM. You had claimed at September 29, 2013 at 11:34 pm that is said, “something like”
“climatic trends should not be considered in periods of less than 30 years”.
But the FAR said nothing like that.
Indeed, the FAR was published in 1990 and four years later in 1994 the IPCC used 4-year periods to assess changes(i.e. trends) in hurricane frequency.
Furthermore, the context of the point put to you – and you were answering – was and is that the ’30-year limit’ has been introduced to hide the halt to global warming over the most recent – at least – 16 years.
My post explained that the quotation you provided from the FAR SPM does not suggest anything like you said. I replied
I am replying to your response to that which is as disingenuous as your post I rebutted. That response says in total
You did not SAY the FAR SPM suggested there could be a halt to warming “for a decade or more”, but in context you SUGGESTED that.
You claimed the FAR SPM suggested “something like” a need for 30-years to assess climate. IT DID NOT.
What the IPCC said was that “unequivocal detection of the enhanced greenhouse effect” would require “a decade or more”. Well, there has been much more than two decades, and that “unequivocal detection“ has receded.
Nick, if you continue to spin like this you will drill yourself into the ground.
Richard