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.
Don’t get me wrong, my skeptical credentials are above reproach, but the breakdown of the temperature anomaly record into chunks of differing linear trends is a little dishonest if the gaps between linear segments invariably contain discreet upward jumps.
“I don’t remember the IPCC suggesting that after just a decade of warming, when they wrote their first report.”
I don’t know of any scientific basis for this. Is there one? It seems like pure heuristics.
Thank you, Paul. Clearly some reporters need a kick in the pants to get them investigating properly, as many still have their CAGW blinkers firmly in place.
As the alarmist crowd will now start insisting on a 30 year wait for confirmation, we might be wise to apply that straight back at them (every chance we get), as that first warming “trend” that triggered the first alarmist claim was so short. “You’re right,” we can say, “And that kicks out the warming meme right from the start.”
We’ve got to teach these guys and gals that they can’t have their cake and eat it too.
I still can’t get over Michael Mann calling Judith Curry a “serial climate disinformer.” Somehow the words “pots,” “kettle,” and “black” come to mind…
“But look deeper, and you will see this is a piece of devious trickery.”
Tomorrow the IPCC is set to release the report titled “The Physical Science Basis.” Namely, the report the “summary” is supposed to have summarized. The only reason not to release the two on the same day is the summary does not exactly jibe with the report (an IPCC tradition). So even deeper looks for devious trickery in the summary are likely worthwhile starting tomorrow.
Tom Jones says:
September 29, 2013 at 3:59 pm
there is no scientific basis for that statement – and the goalposts keep getting moved!
Excellent analysis. The IPPC and its hangers on couldn’t be honest if their lives depended on, its their stock and trade!
the odds of one in eight suggest the observed slowdown was due to happen…
…still batting zero
Tom Jones says:
September 29, 2013 at 3:59 pm
“I don’t remember the IPCC suggesting that after just a decade of warming, when they wrote their first report.”
I don’t know of any scientific basis for this. Is there one? It seems like pure heuristics.
*
Tom, the alarmists couldn’t wait to launch the fear-mongering. 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. They’ve just doubled up on the 15 years they first claimed to need – just how many times do they have to move the goal post before we say enough is enough? The alarmists have had their way, way too often and for way too long, with WAY too much funding. It’s more than time to draw the line.
Even WUWT is being shunted onto the back foot in the fight over the term to describe the trend since 2001. The alarmists were calling it a pause or a hiatus a year ago when the Daily Mail broke the story and sceptics weren’t happy with that because it implied knowledge that the rise would continue at some future date.
Then they started calling it a slowdown. That was a plain lie so the sceptics said it’s a pause forgetting that they had ceded part of the semantic terrain. You are now using their term, ‘pause’, a loaded term. You have no certain knowledge that the upward trend will resume in the future.
There is only one word applicable at present. It is a halt.
If the next year of temp data shows enough downturn to show more than the hundredths of a degree we currently see, I think you can progress to ‘downturn’.
But right now, it is not a pause.
Reblogged this on wwlee4411 and commented:
When you have an agenda you’re trying to advance you have to be willing to do everything you can to protect it. Especially when it is being revealed to be based on lies, falsehoods, and deception. It is particularly important, and thus vulnerable, when it is affected by power and money.
It is a halt….
100% correct
Anthony, how about a bet on how soon a “new Ice Age” meme will arise?.
Just finished reading “Why the West Rules – for Now” by Ian Morris 2010. Gripping analysis of how history can be linked to archaeology to get the broad sweep. Morris shows how climate influences social development in both Asia and Europe. The response to the warm periods and cool downs are strikingly similar on both sides of Eurasia. It might have been luck that the West got past the Little Ice Age better than the East. But the threat of global cooling is real and our ability to respond to it is a worry. Morris has a chapter on future outlook but doesnt include the new ice age possibility. Maybe we are just a couple of Pinatubos away from a real bad scene.
“One reason is that 1998, the year invariably chosen by sceptics, was one of the warmest ever.”
Typical strawman. Skeptics don’t make the argument that they declare “invariable”.
First, we don’t start at a point in the past. Our starting point is not 1998, it is 2013. Then we see how far back we can go, and still have a trend so low that it demonstrates the lack of skill of the climate models. If temps were rising as the models had predicted, we would no be able to go back very far.
Second, we don’t end in 1998, either. Most analyses of the model-busting break in trend currently indicate ~17 years of insignificant trend. They end in 1996 or 1997 – the pre-trough or mid-rise rather than the El Nino peak in 1998. This 17 year period is longer than the NASA modelers had previously claimed was the longest period consistent with their predictions. It is as long as the period that Santer et al gave as the starting point for its soon to be continuous goal-post-moving exercise.
Recent Met Office research investigated how often decades with a stable or even negative warming trend appeared in computer-modelled climate change simulations.
Negative warming trend. Otherwise known as a cooling trend outside of the circle of activist climate pseudoscientists.
I have said this before..
My feeling is Carbon tax schemes will cause a greater threat then sub prime and CDS’s ever did in time. If the global temperatures do decline like I feel they will all hell is going to break lose.
We are all doomed!!!
i agree with scute,it is a halt ,cessation,complete stop of “warming” . though to be fair ,if the room temperature in my sitting room increased or decreased by 0.8c i would not call it warming or cooling ,i would be hard pressed to notice.it certainly cannot be described as a pause,as that implies that at some point in the near future it will resume.
i really look forward to those with far better knowledge than i to really examine the report for errors.there is one obvious one regarding the claim of deep ocean warming in the 2000 m to 3000 m range ,and beyond 3000 m depth,where as far as i know there have been no statistically significant measurements taken. to me,this means the attribution of the heat to the deep oceans is based purely on belief and not physical measurement.
Just a reminder for some, regarding the global temperature rise (happening since the late 1800s, stepwise or otherwise) and the IPCC report, Richard Lindzen recently said:
” in attributing warming to man, they fail to point out that the warming has been small, and totally consistent with there being nothing to be alarmed about. …”
Very few of the so called skeptics deny this small temperature rise during that particular period.
One more thing. Hiding the decline is an addiction with this lot. I tried this before with this same topic (to no avail…which is my expectation again), but we should come up with a list of inconvenient declines they would rather not discuss. I have a few to start with:
• The decline in the rate of warming since 1980
• The decline in the warming since 1998
• The decline in the rate of sea-level rise
• The decline in concern over climate change
• The decline in deaths from extreme weather
• The decline in major hurricanes
• The decline in NH ACE
• The decline in hair count on Mann’s head
UnfrozenCavemanMD, in those upward gaps I think you may be seeing the signatures of the unnatural upward adjustments (or downward in the distant past). That is, can the entire Earth globally warm that fast to create those curiuos upward gaps in such charts?
Its obvious that the real threat is global cooling – shorter growing seasons, unseasonal frosts, hardship and hunger.
Humans have nothing to fear from a warmer climate, we are one of the most hot climate adapted animals on the planet. In anything except the baking tropical savannahs and jungles of our distant ancestors, we have to wear clothes to protect us from the cold.
Why are we so well adapted to the heat? It goes back to how our ancestors used to hunt. We couldn’t run faster than an antelope, but we could run further than an antelope, in hotter weather, until the antelope ran out of steam and simply lay down and died.
http://en.wikipedia.org/wiki/Persistence_hunting
when the question is “how long has it been since there has been any statistically significant warming?” its is impossible to cherry pick a start date because the start date is now
JJ
I had just that problem yesterday in the comments on this BBC article.
http://www.bbc.co.uk/news/science-environment-24308509
I was accused of using a start date ‘around’ a high El Niño event. I had stated ‘1997’ so this guy knew I was avoiding the 1998 peak in order not to cherry-pick. He still went for that knee jerk argument thinking I wouldn’t call him on it. I did.
I even got accused of cherry-picking my end date (your start date), the present, because one day in the distant future the present could be in the middle of a Maunder type minimum!
There are possibly millions reading these articles and many thousands reading the comments. And these guys are doing their best to erode the sum of human knowledge just by turning up to comment and leaving little bomblets all over the shop for me to diffuse.
For anyone who’s interested (and I wouldn’t actually expect anyone to traipse over there and read them) it’s Scute versus Sagacity from comments 25 to 50. Plus a tag partner who fans the flames when Sagacity goes shopping.
This isn’t a “hide” or a “trick” or a “downplay”.
It’s a deliberate misrepresentation designed to extract money from others.
Also known as fraud!
I don’t remember the IPCC suggesting that after just a decade of warming, when they wrote their first report.
The figure proclaimed (much later) was 17 years and will no doubt become 70 if the cooling trend continues indefinitely.
In order to separate human-caused global warming from the “noise” of purely natural climate fluctuations, temperature records must be at least 17 years long, according to climate scientists.
And:
Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature.
From our old friend Ben Santer-punch. Santer, Stocker, and then someone else off the bench to extend it if necessary. Don’t expect them to yield an inch, ever. Thus we shall never stop fighting and exposing this fraud until they are embarrassed to even broach the subject of AGW…likely not in our lifetimes.